appendix e best available techniques assessment

MT PIPER ENERGY RECOVERY PROJECT

APPENDIX E BEST AVAILABLE TECHNIQUES ASSESSMENT

Mt Piper Energy Recovery Project – BAT Assessment ___________________________________________________

Report for Re.Group

ED 13034100 | Issue Number 4 | Date 13/10/2019 Ricardo in Confidence

Mt Piper Energy Recovery Project – BAT Assessment | i

Ricardo in Confidence Ref: Ricardo/ED13034100/Issue Number 4

Ricardo Energy & Environment

Customer: Contact:

Re.Group Rob Davies Ricardo Energy & Environment Gemini Building, Harwell, Didcot, OX11 0QR, United Kingdom

t: +44 (0) 1235 75 3230

e: [email protected]

Ricardo-AEA Ltd is certificated to ISO9001 and ISO14001

Customer reference:

BAT Assessment

Confidentiality, copyright & reproduction:

This report is the Copyright of Re.Group. It has been prepared by Ricardo Energy & Environment, a trading name of Ricardo-AEA Ltd, under contract to Re.Group dated 08/08/2019. The contents of this report may not be reproduced in whole or in part, nor passed to any organisation or person without the specific prior written permission of the Commercial Manager, Ricardo Energy & Environment. Ricardo Energy & Environment accepts no liability whatsoever to any third party for any loss or damage arising from any interpretation or use of the information contained in this report, or reliance on any views expressed therein.

Author:

Rob Davies

Approved By:

David Woolford

Signature

Date:

13 October 2019

Ricardo Energy & Environment reference:

Ref: ED13034100- Issue Number 4

Mt Piper Energy Recovery Project – BAT Assessment | ii



Table of contents

1 Introduction ................................................................................................................ 3 1.1 Background .................................................................................................................. 3 1.2 Objectives..................................................................................................................... 3 1.3 Overview of the ERP .................................................................................................... 3 1.4 Assessment .................................................................................................................. 4 1.5 References ................................................................................................................... 5 1.6 Costs ............................................................................................................................ 5

2 Background / Policy Context .................................................................................... 6 2.1 Policy Overview ............................................................................................................ 6

3 Indicative BAT Assessment .................................................................................... 10 3.1 Introduction................................................................................................................. 10 3.2 Refuse Derived Fuel ................................................................................................... 10 3.3 Best Available Techniques .......................................................................................... 10

3.3.1 Combustion Techniques ..................................................................................... 11 3.3.1.1 Moving Grate ........................................................................................... 11 3.3.1.2 Fluidised Bed Combustion ........................................................................ 11 3.3.1.3 Gasification and Pyrolysis ........................................................................ 12

3.3.2 Conclusion ......................................................................................................... 13 3.3.3 Flue Gas Cleaning Technologies ........................................................................ 13

3.3.3.1 Pollution Absorption Systems ................................................................... 13 3.3.3.2 Control of NOx ......................................................................................... 14

3.3.4 Conclusions ....................................................................................................... 14

4 Quantitative BAT Assessment ................................................................................ 15 4.1 Nitrogen oxides abatement method (SNCR vs SCR) ................................................... 15 4.2 Acid gases abatement method (semi-dry vs dry vs wet); ............................................. 15 4.3 Acid gases abatement reagent (lime vs sodium bicarbonate) ...................................... 17

5 Review of Proposed ERP against Indicative BAT .................................................. 18 5.1 Introduction................................................................................................................. 18 5.2 Reference Facility ....................................................................................................... 18 5.3 Technical Criteria ........................................................................................................ 20

6 Assessment against BATC...................................................................................... 23

7 Commentary and Conclusions ............................................................................... 34

Mt Piper Energy Recovery Project – BAT Assessment | 3



1 Introduction

1.1 Background This report has been produced in support of the planning application for the Mt Piper Energy Recovery

Project (‘ERP’).

The proposed ERP comprises a refuse derived fuel (‘RDF’) energy from waste (‘EfW’) plant situated at

the existing EnergyAustralia (‘EA’) Mt Piper Power Station (‘MPPS’), near Lithgow NSW.

The proposed development involves the construction and operation of a dedicated boiler and RDF

receival infrastructure with a design capacity of 200,000 tonnes per annum (tpa). The boiler will be fired

with RDF to generate steam for integration into the existing MPPS, which is coal fired. This will generate

electricity at the existing power station, augmenting the 1,500-megawatt (MW) MPPS with lower

emissions generation and reducing the amount of coal required by the power station.

The development comprises two distinct areas (the ‘Project’):

1. The ERP, where combustion of RDF will occur.

2. The ash placement facility, where ash generated at the ERP will be placed.

This report is only concerned with the first point above, the ERP.

1.2 Objectives Ricardo Energy and Environment (‘Ricardo’) was commissioned to assess compliance of the proposed

ERP development with the NSW EfW Policy requirements. The NSW EfW Policy is published by the

NSW EPA.

1.3 Overview of the ERP The steam generated at the ERP will be supplied into the Mt Piper steam system, at appropriate steam

conditions, to supply the reheat steam loop and, therefore, reducing the amount of coal that would be

required by the power station.

The RDF will be produced elsewhere for delivery to the ERP and no unprocessed municipal or

commercial waste will be accepted at the ERP, which reflects the NSW status where waste incineration

is banned.

The RDF will be delivered in either baled1 or bulk compacted form.

Bulk compacted RDF will be delivered to the ERP by bulk loader and will either be tipped or ejected out

of the trailer using a walking floor mechanism. Bulk compacted RDF will enter a concrete storage bunker

which can hold enough RDF for several days’ operation. This will be contained within the ERP building,

preventing the escape of any material. Odours will be removed by the combustion system which will

draw its air from the ERP building. Should the ERP not be operating, a standby system will operate to

prevent odours being released from the plant.

1 Bales are RDF that has been compressed into a cuboid shape, in a baling machine (a ‘baler’), and then wrapped in a plastic

wrap that seals the bale. A wrapped bale typically weighs between 1-1.5te and is more easily handled and stored without any

release of odour or material.




The RDF will be fed into the feed hopper of the combustor (furnace) by a grab crane which can be

operated by an operator or automatically. The crane will also be used to mix the fuel to ensure greater

consistency of RDF entering the system.

The combustion system will be a moving grate, where the RDF is gradually moved down the grate whilst

it is burning, being agitated by the mechanical action of the grate thereby ensuring an even combustion

and release of heat. Air will be added to the system either through the grate or immediately above it.

The combustion process will be controlled by an advanced control system which ensures that not only

is complete combustion attained, leading to a bottom ash with a very low carbon content, but also that

any compounds present in the combustion gases are destroyed by achieving the regulated conditions

of 850°C for a minimum of 2 seconds.

The ash produced at the end of the grate will be conveyed out of the system and stored prior to transport

to the ash placement facility .

The hot flue gas will then pass into the boiler, where steam will be generated via several heat exchange

surfaces. These surfaces will be kept clean of ash by a variety of inline cleaning technologies to

maintain the efficiency of the process and any ash will be collected at the bottom of the boiler for

disposal.

The steam generated from the boiler will then be supplied by pipe to the adjacent power plant, where it

will be used to generate electricity.

On exiting the boiler, the flue gases will pass into the flue gas cleaning (‘FGC’) plant. The FGC plant,

in conjunction with the combustion control system, is designed to ensure that the plant complies with

all current regulatory requirements in relation to air emissions, and to do this in the most resource

efficient way.

The key elements of the FGC system include the injection of lime and activated carbon to react with

any acid gases or heavy metals, taking them out of the gas stream leaving the cleaned flue gas to pass

up the stack. Any ash, together with the lime and activated carbon following reaction, will be captured

by a fabric (bag) filter and stored in silos prior to being taken away from the ERP by road. Additionally,

the plant includes for the upstream injection of urea into the upper part of the combustion chamber, to

control emissions of nitrogen oxides (‘NOx’).

1.4 Assessment The assessment undertaken and discussed in this report is based upon the following brief/requirements:

a) Qualitative commentary on the “current international best practice” for “proven, well understood

technology” as described in the NSW Energy from Waste policy. The commentary includes

reference to European (e.g. Industrial Emissions Directive and Best Available Techniques

Reference document) and non-European best practice.

b) A summary of the techniques nominated in the project documents. Where techniques are not

identified in the relevant project documents, Consultant is to clarify or identify proposed measures

(e.g. operational controls) for confirmation by technology provider or Owner. The scope of

techniques/technologies to be considered includes all aspects of the Best Available Techniques

Reference document, including receipt of fuel and ash handling

c) A Quantitative BAT Assessment, justifying the techniques/technologies selected in comparison with

other technologies. In particular, considering:

i) Nitrogen oxides abatement method (Selective Non-Catalytic Reaction-SNCR vs Selective

Catalytic Reaction- SCR);

ii) Acid gases abatement method (semi-dry vs dry vs wet);




iii) Acid gases abatement reagent (lime vs sodium bicarbonate); and

iv) Combustion technology and/or parameters.

d) Commentary with a clearly stated conclusion on whether:

i) The selected technology and techniques are “capable of handling the expected waste and

variability” and whether this is adequately demonstrated through the references nominated; and

ii) The concept design includes “Heat recovery as far as practicable”.

1.5 References The ERP is currently at the proposal stage and, whilst the key principles of the design have been

identified, the detailed design has not yet been completed. The information on which this report is

predicated has been provided by Re.Group, with additional reference information considered for the

purposes of completing the BAT assessment.

Information provided by Re.Group:

Preliminary Technical Proposal for Mt Piper Project (12 February 2019) - Steinmüller Babcock

Environment GmbH

Feasibility Report Energy Recovery Project - Technology Selection – EnergyAustralia/Re.Group

Mt Piper Energy Recovery Project Knowledge Sharing Report - Version 1.0 – 23 March 2018 -

EnergyAustralia/Re.Group

Draft Air Quality Impact Assessment, Mt Piper Energy Recovery Project – ERM July 2019

Additional reference information:

Environmental Statement 2019 – IKW Rudersdorf Waste to Energy Plant – Steag - https://www.steag-

waste-to-energy.com/uploads/pics/Umwelterklaerung2019_engl_kl..pdf (Accessed August 2019)

EU 2010 Directive 2010/75/EU of the European Parliament and of the Council of 24 November 2010

on Industrial Emissions (Integrated Pollution Prevention and Control), Official Journal of the European

Union, 17 December 2010 (the ‘Industrial Emissions Directive’, or ‘IED’).

EU 2000 Directive 2000/76/EC of the European Parliament and of the Council of 4 December 2000 on

the Incineration of Waste, Official Journal of the European Communities, 28 December 2000 (the

‘Waste Incineration Directive’, or ‘WID’).

IPPC 2006, Reference Document on Best Available Techniques for Waste Incineration, European

Commission Integrated Pollution Prevention and Control, August 2006,

http://eippcb.jrc.ec.europa.eu/reference/BREF/wi_bref_0806.pdf (accessed July 2019)

Best Available Techniques Reference Document for Waste Incineration, European Commission Joint

Research Centre Directorate B European IPPC Bureau, December 2018,

http://eippcb.jrc.ec.europa.eu/reference/BREF/WI/WI_BREF_FD_Black_Watermark.pdf, (accessed

July 2019)

1.6 Costs This report discusses the broad technical options that are available to meet and exceed the environmental requirements of the project. At this time a review of the directly associated capital and operational costs of each option has not been progressed.

A further review into the viability of these options against local costs and drivers, for example costs of effluent treatment, water quality, availability and cost of reagents and disposal routes may be required by the Client but are not within the scope of this report.

https://www.steag-waste-to-energy.com/uploads/pics/Umwelterklaerung2019_engl_kl..pdf

https://www.steag-waste-to-energy.com/uploads/pics/Umwelterklaerung2019_engl_kl..pdf

http://eippcb.jrc.ec.europa.eu/reference/BREF/wi_bref_0806.pdf

http://eippcb.jrc.ec.europa.eu/reference/BREF/WI/WI_BREF_FD_Black_Watermark.pdf




2 Background / Policy Context

2.1 Policy Overview NSW Energy from Waste Policy Statement (2015)

EfW technology is primarily regulated via the adopted NSW Energy from Waste Policy Statement2 (“the

Policy”). The NSW EPA3 states that the Policy encourages EfW if it can deliver positive outcomes for

people and the environment and that it ensures that EfW:

• Poses minimal risk of harm to human health and the environment.

• Facility emissions are below levels that may pose a risk of harm to the community.

• Does not undermine higher-priority waste management options, such as avoidance, reuse or

recycling.

• Meets current international best practice techniques, particularly with respect to process design

and control, emission control equipment design and control, and emission monitoring, with real-

time feedback to the controls of the process.

The Policy is prescriptive and sets-out the requirements listed below. It is important to note that the

Policy sets out two levels of control for EfW processes. The first level applies to certain ‘eligible’ wastes

when treated in EfW facilities, and the second to all other waste types, with more stringent controls

being applied in facilities that are then termed energy recovery facilities.

• Eligible waste derived fuels are permitted for use in simple combustion processes with limited

controls. This is because those fuels pose a low risk of harm to the environment and human

health due to origin, low levels of contaminants and consistency over time (what is ‘eligible’ is

subject to review by NSW EPA). The Policy defines eligible wastes as:

o Biomass from agriculture, forestry, sawmills and virgin paper pulp residues.

o Uncontaminated wood waste.

o Recovered waste oil.

o Landfill gas and biogas.

o Source separated green waste when used to make char.

o Tyres in cement kilns only.

• Waste must be unavoidable residual waste, where material recovery is not financially or

technically viable.

• EfW must represent the most efficient use of the resource and be achieved with no increase in

the risk of harm to human health or the environment (referring to the Protection of the

Environment Operations Act 1997 (POEO Act), which sets the framework to ensure that human

health and the environment are protected from the inappropriate use of waste). In relation to

EfW of eligible fuels:

2 https://www.epa.nsw.gov.au/-/media/epa/corporate-site/resources/epa/150011enfromwasteps.pdf?la=en&hash=50211762E1746B2E444D3869E5E409183312B5BB 3 https://www.epa.nsw.gov.au/your-environment/waste/waste-facilities/energy-recovery

https://www.epa.nsw.gov.au/your-environment/recycling-and-reuse/warr-strategy/the-waste-hierarchy

https://www.epa.nsw.gov.au/-/media/epa/corporate-site/resources/epa/150011enfromwasteps.pdf?la=en&hash=50211762E1746B2E444D3869E5E409183312B5BB

https://www.epa.nsw.gov.au/-/media/epa/corporate-site/resources/epa/150011enfromwasteps.pdf?la=en&hash=50211762E1746B2E444D3869E5E409183312B5BB

https://www.epa.nsw.gov.au/your-environment/waste/waste-facilities/energy-recovery




o A resource recovery order or exemption must have been granted by the EPA.

o The emissions standards set out in the Protection of the Environment Operations

(Clean Air) Regulation 20104 must be met.

o Facilities need to meet current international best practice techniques, particularly with

respect to process design and control, emission control equipment design and control,

and emission monitoring with real-time feedback to the controls of the process.

• That ‘mass burn’ incineration (waste destruction or energy recovery from unprocessed mixed

waste streams) is not acceptable, and innovation is encouraged.

• Facilities that do not treat only eligible wastes must meet the requirements of an energy

recovery facility (ERF), in summary:

o Apply current international best practice techniques, particularly with respect to process

design and control, emission control equipment design and control, emission

monitoring with real-time feedback to the controls of the process (and the following

which are over and above the requirements for eligible waste) arrangements for the

receipt of waste; and management of residues from the energy recovery process.

o Facilities must use technologies that are proven, well-understood, capable of handling

the expected variability and type of feedstock and be demonstrated through fully

operational plants using the same technologies and treating like waste streams in other

similar jurisdictions. Must meet the following technical criteria:

▪ Meet 850°C for at least 2 seconds in the combustion chamber [equivalent to

the European Industrial Emissions Directive] or 1100°C for 2 seconds if the

waste contains more than 1% of halogenated organic substances, expressed

as chlorine.

▪ Meet or exceed the Group 6 emission standards in the POEO Act [Ricardo

assumes that the limits for ‘general activities and plant’ apply] (solid particles

50 mg/m3; NOx 350 mg/m3; SOx 100 mg/m3; H2S 5 mg/m3; HF 50 mg/m3; Cl

200 mg/m3; VOCs 40 mg/m3 or CO 125 mg/m3; HCL 100 mg/m3; Cd or Hg 0.2

mg/m3; dioxins or furans 0.1 ng/m3; type 1 (Sb, As, Cd, Pb, Hg) and type 2 (Be,

Cr, Co, Mn, Ni, Se, Sn, V) substances 1 mg/m3; smoke Ringelmann 1 or 20%

opacity.

▪ Continuous measurements of NOx, CO, particulates, total organic

compounds, HCL, HF and SO2 and available in real time to the EPA, plus

combustion temperature, pressure and temperature in stack, oxygen

concentration and water vapour in exhaust gas.

▪ Proof of performance trials as part of the licence conditions to demonstrate

compliance with emissions limits and subsequently twice-yearly

measurements of heavy metals, PAHs, chlorinated dioxins and furans, and all

to be subject to continuous monitoring if and when appropriate measurement

techniques are available.

▪ Total organic carbon (TOC) or loss on ignition (LOI) content of the slag

and bottom ashes must not be greater than 3% or 5% (dry weight)

respectively.

4 https://www.legislation.nsw.gov.au/regulations/2010-428.pdf

https://www.legislation.nsw.gov.au/regulations/2010-428.pdf




▪ Waste feed interlocks to prevent feeding when required temperature

has not been reached.

▪ Air quality impact assessment must be undertaken in accordance with

the Approved Methods for the Modelling and Assessment of Air

Pollutants in NSW.

o Thermal efficiency criteria:

▪ Plants that do not recover energy are outside the scope of the Policy.

▪ At least 25% of energy will be captured as electricity (or an equivalent level of

recovery for facilities generating heat alone).

▪ Any heat must be demonstrated to be recovered as far as practicable.

o Resource recovery criteria:

▪ Feedstock must be from waste processing facilities or collection systems that

meet specific criteria, unless agreed by the EPA on a case-by-case basis.

▪ For mixed municipal waste there are limitations on waste that can be subject

to EfW depending on whether the council separately collects dry recycling,

food and green waste.

▪ Mixed commercial and industrial waste that can be subject to EfW is limited if

no separate collections are in place for all waste streams being generated.

▪ Mixed construction and demolition waste can only be subject to EfW up to 25%

by weight.

▪ Limits apply to the percentage of residues from the processing of separated

recyclables, green and food waste that can be subject to EfW.

▪ Waste wood and textiles can be subject to EfW if sourced directly from a waste

generator (e.g. manufacturing).

o Other requirements:

▪ Waste must not contain batteries, light bulbs, other electrical and hazardous

waste.

• An EfW or ERF development must be subject to public consultation; engage in genuine

dialogue with the community; ensure that planning consent and other approval authorities are

provided with accurate and reliable information; and be ‘good neighbours’, particularly when

near residential areas and employment.

Further consideration of NSW Energy from Waste Policy

Since the publication of the Policy, Federal and State Environment Ministers agreed at the 7th meeting

of Environment Ministers on 27 April 2018 to a series of 6 announcements, including investigation of

waste to energy in line with the waste hierarchy5.

“Ministers agreed to… Explore opportunities to advance waste-to-energy and waste-to-

biofuels projects, as part of a broader suite of industry growth initiatives, recognising the

reduction, reuse and recycling of waste is a priority, consistent with the waste hierarchy.

This will include support from the Clean Energy Finance Corporation and the Australian

Renewable Energy Agency.”

5 https://www.environment.gov.au/system/files/pages/4f59b654-53aa-43df-b9d1-b21f9caa500c/files/mem7-agreed-statement.pdf

https://www.environment.gov.au/system/files/pages/4f59b654-53aa-43df-b9d1-b21f9caa500c/files/mem7-agreed-statement.pdf

https://www.environment.gov.au/system/files/pages/4f59b654-53aa-43df-b9d1-b21f9caa500c/files/mem7-agreed-statement.pdf




Also post-dating the Policy, the 2018 Australian Senate Inquiry into waste and recycling and an

extension of the NSW Parliamentary Inquiry into Energy from Waste6 published “‘Energy from Waste’

technology”. The objectives included: consideration of the “role of ‘energy from waste’ technology in

addressing waste disposal needs”, a review of worldwide regulatory standards for EfW and “additional

factors which need to be taken into account within regulatory and other processes for approval and

operation of ‘energy from waste’ plants”.

The inquiry acknowledged concerns over EfW, particularly whether they pose an undue risk to human

health and the environment but recognised the importance of managing waste in accordance with the

waste hierarchy and the NSW Waste Avoidance and Resource Recovery Act 2001, which dictate that

energy recovery is preferable to disposal. The inquiry report goes into a detailed discussion of the

findings of the inquiry, which is outside the scope of this review. There is however a notable reference

to the need for a reference facility and that this stifles innovation and investment.

There is also reference to the expectation of the NSW EPA publishing Energy Recovery Facility

Guidelines in early 2018, indeed its publication forms a specific recommendation of the inquiry.

However, at the time of writing the EPA website refers to this document as being in progress.

Considering these anticipated guidelines, and a further recommendation to set up an “expert advisory

body on energy from waste chaired by the Chief Scientist to examine and report on the energy from

waste regulatory framework”, Ricardo would anticipate an update to the Policy in the short-medium

term.

6 https://www.parliament.nsw.gov.au/committees/DBAssets/InquiryReport/ReportAcrobat/6146/Final%20-%20Report%2028%20March%202018.pdf

https://www.parliament.nsw.gov.au/committees/DBAssets/InquiryReport/ReportAcrobat/6146/Final%20-%20Report%2028%20March%202018.pdf

https://www.parliament.nsw.gov.au/committees/DBAssets/InquiryReport/ReportAcrobat/6146/Final%20-%20Report%2028%20March%202018.pdf




3 Indicative BAT Assessment

3.1 Introduction This section of the report identifies the technology groupings that are currently considered “Best

Practice” internationally, drawing on experience in Europe, the USA and Asian markets (in particular

the European market). The use of these technologies can be dependent on the nature of the fuel and

wider scope of the project, and so following a review of the key policy drivers, we identify the fuel type

proposed and how it fits within the resource hierarchy.

3.2 Refuse Derived Fuel Before entering into a discussion on the different technologies, it is important to note that this project is

based upon the use of an RDF prepared from Municipal Solid Waste. The EFW Policy states very

clearly that some facility types are excluded from compliance. One of these specific categories that

excluded facilities include those that are “facilities proposing the thermal treatment of unprocessed

waste streams”.

This is an important reference as it makes clear that any fuel must first be processed to remove anything

of immediate value to the resource market leaving only residual elements with no current value to be

combusted within an Energy from Waste scheme.

A Refuse Derived Fuel (RDF) is derived from residual waste that has been through a processing

operation, removing metals and other readily recyclable items as well as non-combustible materials

(bricks, stones, glass etc) before shredding the material to a consistent size that can be transported

either in bulk compacted form or baled and wrapped for longer term storage.

Therefore, it is apparent that the Mt Piper Energy Recovery Project meets the requirements of the Policy

in terms of its feedstock, i.e. that “Further material recovery through reuse reprocessing or recycling is

not financially sustainable or technically achievable” though is not classified as one of the “Eligible

Waste Fuels”.

3.3 Best Available Techniques This section considers the Best Available Techniques (BAT) in each of the main areas of consideration

under the NSW EFW Policy document as they are seen in the EU, but also drawing on the experience

elsewhere in the world.

It should be noted that many industrialised nations draw upon UK and European standards for their

projects and define their national standards using these as a starting point. As an example, many

projects in the Middle East also refer to these standards as being best practice for any implementation

of projects. For this reason, consideration of BAT, in this report, particularly focuses on European

standards.

The NSW EFW Policy document also draws a distinction that any technology used should be “proven,

well understood technology” and therefore those technologies that are considered to be emergent or

disruptive technologies are not considered here.




3.3.1 Combustion Techniques

There are a number of different technologies that exist for the combustion of municipal waste derived fuels. In general, the proven technologies can be grouped into 4 main categories which we discuss here.

• Moving Grate

• Fluidised Bed

• Gasification

• Pyrolysis

3.3.1.1 Moving Grate

Overview

Worldwide, the vast majority of plants used for the thermal treatment of municipal waste utilise moving

grate technology. Moving grates exist in a variety of different designs (roller grates, reverse

reciprocating, reciprocating) but each involves the use of a system that distributes the fuel across a

grate. A mechanism for moving the material down the grate as it burns, agitating and turning the

material as it does so, whilst primary air is blown through the grate to support the combustion. This

allows for good mixing of material, breaking it up as it progresses. Secondary air is commonly

introduced above the grate, creating areas of turbulence to ensure the complete burn out of volatile

compounds.

Moving grate technology can be used for a wide range of fuels as the control systems can vary the

residence time that the material remains on the grate thereby ensuring good burnout and a low TOC

content in the bottom ash.

Environmental Performance

The moving grate system is well established technology and the provision of advanced control of the

combustion system means that it can operate with low NOX levels. However, it will still not achieve the

requirements of the industrial emissions directive (‘IED’) without the addition of secondary measures.

Incorporation of SNCR (discussed later) means that the NOX levels set by the IED can be achieved

(400 ppm for ½ hr average and 200 ppm for daily average, noting that the EPAs Group 6 Emissions

from the Protection of the Environment Operations (Clean Air) Regulation 2010 limit is 357 ppm for 1

hr average).

In relation to ash generated, in general terms the moving grate presents most of the ash (~80%) as

bottom ash with the remainder being carried into the gas path to be extracted by the Flue Gas Cleaning

Plant. With the bottom ash being able to be reprocessed in some economies, this creates even more

opportunities for resource recovery.

3.3.1.2 Fluidised Bed Combustion

Overview

Fluidised bed combustion systems require a reasonable degree of pre-treatment of the fuel to ensure

that it is of a consistent size and free of non-combustible elements. It is typically used on biomass and

sludge-based fuels due in part to the high degree of consistency of the fuel and the thermal “inertia”

within the sand medium used to support the combustion process. An RDF fuel, where incombustibles

are removed, would be appropriate for this type of technology based on fuel feed characteristics.

Fluidised Bed systems exist in a number of different forms, from bubbling bed (where the bed material

remains in a contained volume within the first pass/combustion chamber) to circulating bed types (where

the material is subject to a greater primary air flow, carrying the bed material through the first pass at

the top of which it passes through a cyclone to return the bed material and unburnt material to the base

of the combustor).




While fluidised bed combustion can lead to slightly lower NOx generation, the injection of ammonia

solution or urea is still required to achieve the emission limits specified in the waste incineration articles

of the IED and relevant BAT Reference Notes.


In general, Fluidised Bed Combustion can achieve lower NOx levels as thermal NOx generation can be

lower. However, even assuming for a pre-prepared fuel, the overall the energy efficiency of the plant

is lower due to the greater energy flows required by the process.

With regards to ash generation, the sand material of the bed has a degradation through the constant

agitation of the bed and adds a further element of material to the fly ash. The proportion of bottom ash

to fly ash is much more in favour of the production of fly ash in fluidised bed systems, whether bubbling

or circulating.

3.3.1.3 Gasification and Pyrolysis

Overview

Pyrolysis is the thermal degradation or decomposition (thermolysis) of organic materials by heat,

without combustion, in either the complete absence of oxygen or where it is so limited that gasification

does not occur to any appreciable extent. Conventional pyrolysis takes place at temperatures between

400-900°C and products include syngas, liquid and solid char. Liquid product is also known as pyrolysis

oil, olefin, or bio-oil when processing biomass. Utilising pyrolysis for waste treatment is currently less

well developed than gasification although there are some examples of these systems being installed.

Pyrolysis is a mature technology in terms of its application to coal, peat and liquid fossil fuels, however

there are limited examples in its application to waste derived fuels. There is some experience of slow

pyrolysis of MSW, but these still tend to be in development stages, and there are several examples of

project failures (for example, the MSW and clinical waste-based pyrolysis process operated by Compact

Power, later Ethos, in the UK is no longer operational). Successful examples of pyrolysis tend to be

those plants using homogenous waste streams such as tyres and wood chip. There are different

configurations of pyrolysis equipment, including fluidised bed, moving bed and rotating cone.

The design of the pyrolysis process will impact on the characteristics of the process outputs. For

example, slow pyrolysis will produce charcoal, oil and gas, whereas fast pyrolysis is designed to

maximise the production of pyrolysis oils. The pyrolysis process requires the input of energy to sustain

pyrolysis process (equivalent to 20-25% of input energy). Whilst gasification systems can be designed

to release some of the energy in the feedstock to sustain the gasification process, Pyrolysis generally

needs energy from an external source to sustain the process.

Gasification is the thermal breakdown/partial oxidation of waste under a controlled oxygen atmosphere

(the oxygen content is lower than necessary for combustion). The waste reacts chemically with steam

or air at a high temperature (>750°C). The process is sustained by the heat generated by the partial

combustion of the feedstock. The syngas (primarily consisting of CO and H2) produced by gasification

has a lower calorific value than pyrolysis gas and is dependent upon the gasification process. The tar

levels in the syngas are lower than for pyrolysis gas but depend on the actual gasification technology.

Potential syngas uses are the same as for pyrolysis.

Gasification technologies have been promoted heavily within the UK as one of the Advanced Thermal

Conversion (ATC) technologies that were eligible for additional electricity subsidies when using biogenic

wastes, of which Municipal Waste was considered eligible. A number of schemes have been installed

in the UK, but to date many have experienced problems in their construction and commissioning and

have not yet achieved their promised potential.





Although the syngas produced by either pyrolysis or gasification has potential uses in many applications

if it can be subject to an appropriate cleaning and purification process, the only systems to have been

installed at scale are relatively close coupled systems that immediately combust the syngas to generate

steam and subsequently electricity. The char produced from the process contains heavy metals and

other contaminants and may be classified as a hazardous waste in some jurisdictions.

3.3.2 Conclusion

From the above assessment and the requirements of the NSW EPA Energy from Waste Policy, it is

clear that the most proven, and hence BAT for the treatment of municipal waste derived fuels such as

RDF is the moving grate combustion system. When fitted with an advanced combustion control system

it is able to achieve good burn out of combustion products and produce bottom ash that is low in total

organic carbon (TOC). Secondary flue gas treatment systems are still required for the control of oxides

of nitrogen as would be standard across the technology selection.

3.3.3 Flue Gas Cleaning Technologies

3.3.3.1 Pollution Absorption Systems

Basic FGT is regarded as being raw combustion gas treatment to limit the emissions of: particulate

matter or dust; acidic gases (Hydrogen chloride HCl, Hydrogen fluoride HF and Sulphur dioxide SO2);

heavy metals (mainly adsorbed on the surface of fly ash particles); and dioxins (highly toxic molecules

produced in very small amounts during part of the combustion process, absorbed by activated carbon

reagent).

NOx is treated in a separate system within the EfW plant, see below.

Carbon monoxide (CO) and TOC content requirements are addressed by controlling the combustion

conditions in the furnace.

Absorption systems are categorized into distinct systems: dry, semi-dry, wet systems and combinations

thereof:

• ‘Dry’ systems are where the chlorine and sulphur content of the waste leaves the facility as a

dry product, and no wastewater is produced. This system is commonly employed in EfW plants.

Lime is the most commonly used reagent in a dry system, sodium bicarbonate-based systems

are also specified where there is a market that is able to supply and recover the reagent.

Another differentiator between lime and Sodium Bicarbonate is the need to remove the fly ash

from the system before the introduction of the reagent, to avoid contamination. This requires

the addition of a further separation stage which would typically be an Electrostatic Precipitator

(ESP) due to its presence in a higher temperature gas stream as the optimum reaction

temperature is greater than that for hydrated lime. This means that the efficiency of the heat

recovery system is lower due to higher stack losses.

• ‘Semi-dry’ systems where hydrated lime and water are added to the gas stream, the moisture

evaporating to leave dry products. The reagents may be recirculated to reduce reagent

consumption. Both dry and semi dry systems employ a bag house filter to capture residues for

disposal.

• ‘Wet’ scrubbing systems have several processing stages. These include a wet scrubber that

produces a calcium chloride solution containing the majority of the chloride released from the

combusted waste, thereby limiting the generation of solid residues.




3.3.3.2 Control of NOx

Waste combustion in grate fired systems results in the production of several oxides of Nitrogen

described collectively as NOx. The most commonly employed system to remove NOx from the flue

gases is Selective Non-Catalytic Reduction (SNCR).

The SNCR process entails ammonia water, or urea, injection in the upper part of the combustion

chamber of the furnace where gasses are at a temperature of 850-950°C. These temperatures are

suitable for ammonia to react with nitrogen oxide (NO) and nitrous oxide (NO2). Optimisation of the

process requires careful control of ammonia injection, flow rates and stable combustion control.

Depending on the level of optimisation, the process causes some un-reacted ammonia to leave the

boiler with the flue gas. This is known as ammonia slip.

In both dry and semi-dry FGT-systems, a certain amount of the ammonia slip is caught by the residue

in the bag house filter. The remaining ammonia leaves the plant with the clean flue gas. A typical

requirement for the maximum ammonia slip would be 5 - 10 mg/Nm³, though the slip is indicated as a

limit value in the EU Directive.

Selective Catalytic Reduction (SCR) is an alternative process that can reduce NOx levels further than

SNCR. However, it requires a catalyst to be able to operate as well as a reagent. Due to the costs and

increased complexity (different temperature range, location of injection and catalyst etc) it is considered

BAT to use SNCR.

3.3.4 Conclusions

SNCR has a lower cost of implementation but remains able to achieve the levels of NOx emissions

specified within the IED. Its effectiveness and efficiency of reagent consumption can be monitored

using analysis instrumentation to detect ammonia slip allowing the control system to vary the amount

of reagent added into the system.

For the control of dioxins, the BAT is to ensure that the process achieves the time and temperature

requirements that are specified in IED and in the NSW Policy of 850°C for 2 seconds and then ensure

the correct design of the energy recovery plant to rapidly drop the temperature of the flue gas to prevent

de novo reformation of dioxin. For residual control, and also for control of any heavy metals and

mercury, Activated Carbon injection is BAT.

The selected FGC technology is sometimes classified as a semi dry system as it operates slightly

differently to the dry system described here in that it has a flue gas conditioning/evaporative cooling

system immediately before the injection of dry reagents. This system ensures that the flue gas is at the

correct temperature and humidity, and therefore enhances the efficiency of the system, reducing the

consumption of reagents and offering improved performance to the BAT. The reagent, in addition to

the aforementioned Activated Carbon, is a dry, hydrated lime flue gas cleaning process. In this way

both reagents are injected at a similar location and reaction time is optimised through the plant control

system monitoring both stack conditions and also pressure drop across the bag filter candles.

The above technology selection confirms that the proposed project does represent BAT for the

treatment of RDF.




4 Quantitative BAT Assessment

In this section, a quantitative / semi quantitative BAT assessment is provided, justifying the

techniques/technologies selected in comparison with other technologies.

4.1 Nitrogen oxides abatement method (SNCR vs SCR) There are two abatement methods that are available for the reduction of NOx emissions from a facility.

The difference between these two systems is that one employs a catalyst to provide the conditions for

the reaction which is typically costly in its installation and requires expensive periodic maintenance.

Selective Non-Catalytic Reduction (SNCR) systems can achieve NOx emission levels of around 100 to

150 mg /Nm³ which is well within the current daily average emission limit set in the IED of 200 mg /Nm³.

Selective Catalytic Reduction (SCR) systems can reduce NOx emissions to lower than those seen with

SNCR systems as an SCR system is much more costly to build and operate. Most EfW plants opt for

SNCR as this provides adequate performance within current IED limits, however more recent facilities

have incorporated an allowance within their design for conversion to SCR if needed.

The SNCR system proposed would, therefore, appear to be the best choice in terms of meeting

applicable emissions limits. A more costly SCR system is not justified, noting that the Air Quality Impact

Assessment (AQIA) concludes that there would be no/minimal improvement on the environmental

performance of the facility by reducing the NOx emissions to SCR levels.

4.2 Acid gases abatement method (semi-dry vs dry vs wet); Table 2 below presents positive, neutral and negative aspects of commonly available FGT systems. It

can be seen that no single flue gas treatment concept is advantageous under all the evaluation criteria

considered. Therefore, the evaluation criteria need to be weighed against the specifics of the project,

according to site location, the individual priorities and needs of the operator / owner.

Table 2: Assessment of base concepts for dry, semi-dry, combined and wet FGT technology

Evaluation criteria: Dry Semi-

dry Wet

Operational availability

- Performance history of reliable operation + + 0

- Reduced unavailable risk due to less technical

complexity + + 0

Capability

- Ability to handle changes in raw gas composition - 0 +

Flexibility

- Ability to meet more stringent future emission limit - 0 +

Health and safety




Evaluation criteria: Dry Semi-

dry Wet

- Reduced human contact with hazardous material 0 0 0

Sensitivity to local conditions

- Limited plume visibility + + -

- Discharge of treated wastewater N/A N/A -

Other environmental issues

- Low chemical consumption - 0 +

- Low water consumption + 0 -

- Low electricity consumption + + 0

- Low residue production - 0 +

‘+’= attractive for project, ‘0’= neutral and ‘-‘=negative

When the key assessment criteria are considered, the following conclusions are drawn:

Most attractive concept

A dry or semi-dry FGT system is recommended as being the most attractive option for the Mt. Piper

development. This is due to:

• The system is optimal for EfW plants processing waste where the pollutant content is not

expected to vary significantly in future years.

• Water consumption is low (particularly for a dry system) and there is no production of

wastewater requiring specialist treatment and discharge.

• It is not envisaged that flue gas condensation is beneficial.

• Relatively simple operational requirements.

• Relatively low capital investment requirements.

Alternatives

Wet scrubbing systems are only of interest where:

• Wastewater discharge is an option.

• The waste pollutant load is high.

• There are highly stringent emission requirements and exceptional environmental ambitions.

• Low residue generation is a key factor.

The drawbacks of the system are:

• Increased technical complexity – especially where wastewater treatment is necessary

• Increased plume visibility, particularly in cold climates.

• Higher capital investment requirements.

This would exclude a wet system from consideration for the Mt. Piper development.




4.3 Acid gases abatement reagent (lime vs sodium bicarbonate)

Table 3 below presents positive, neutral and negative aspects of a dry lime and bicarbonate system

relative to each other. Once again, it can be seen that neither reagent is advantageous under all the

evaluation criteria considered and specific project circumstances need to be taken into account.

Table 3: Assessment of lime and bicarbonate reagents

Evaluation criteria: Lime Bicarbonate Comments

Installation and operation

0 0 Either reagent (in a dry system) has low investment

costs and is relatively simple to install and operate

Performance

0 0

Acid gas removal performance is similar for both reagents.

Efficiency of lime usage may be improved by using a higher grade of lime with improved reactivity. Lime is used in many plants, particularly smaller facilities, hence the wide availability of references and operational experience.

Chemical consumption - +

Bicarbonate consumption is more moderate because approximately 20% excess reagent use is typically required.

Chemical costs and supply

+ - Bicarbonate is relatively expensive to purchase and there is often a limited number of suppliers.

Chemical residues

- +

A significant excess of hydrated lime is required to treat flue gases to levels that comply with emission limits. This is typically 100-200% excess hydrated lime and this results in large quantities of residue generation.

With bicarbonate, the use of an electrostatic precipitator before the main process results in a chemical residue at the bag filter, which can in principle be recycled. This reduces the amount of residues produced when compared to a lime-based flue gas treatment plant.




5 Review of Proposed ERP against Indicative BAT

5.1 Introduction Although the RDF meets the requirements of some elements of the policy, it is not classified as an

“Eligible Waste Fuel” and therefore the proposed facility has to comply with the requirements of the

policy in terms of its definition of “Energy Recovery Facilities”.

As such it is required that these plants are using current international best practice techniques in the

following key areas:

• Process design and control.

• Emission control equipment design and control.

• Emission monitoring with real-time feedback to the controls of the process.

• Arrangements for the receipt of waste.

• Management of residues from the energy recovery process.

The above parameters are included within the requirements of the BATC (Best Available Techniques

Conclusions) as set out in the revised draft of the Waste Incineration BAT reference document (BREF).

Although these criteria are currently in draft, they are anticipated to be formulated by the end of 2019

and therefore represent the most likely scenario.

Ricardo’s findings against the BATC are identified in Section 6 of this report and we have provided

commentary against each element where they are both relevant and our opinion in relation to the

requirements of BAT.

5.2 Reference Facility Ricardo recognises that within the Australian market there has been little investment in facilities of this

type. However, confidence can be derived from consideration of other facilities worldwide that are able

to meet the same requirements.

Although many plants exhibit similar attributes, it is important for this project that a reference plant

closely resembling that of the proposed ERP can be identified and, if required, visited to allow any

concerns to be allayed.

The reference facility selected in discussion with the contractor is the Rudersdorf Facility operated by

STEAG. Ricardo understands the reference facility has been visited by the proponents and they have

provided relevant performance data.

The reference facility differs in that it DOES generate electricity itself, rather than providing steam to a

third party to generate electricity on its behalf. However, in all significant aspects, it exhibits strong

similarities to the proposed ERP.

It is important to note that EfW plants suffer significantly greater maintenance costs at steam

temperatures much in excess of 400°C, despite the use of specialist materials (Inconel etc.) due to ash

fusion and high temperature corrosion mechanisms. A steam temperature of 400°C has, therefore,

become a “standard” temperature for modern EfW plants. Turbines are designed against the pressure

and temperature of the steam generated, with higher pressure units driving towards greater efficiency.

It is proposed that the ERP is operated with a steam temperature of 400°C, with flexibility to operate

between 380°C and 425°C.




The plant does utilise RDF as a fuel, with an assumed wide range of flexibility in its “firing diagram”

allowing it to operate on fuels of between 6-18MJ/kg, which is wider than the proposed Mt Piper plant.

The plant has been operating since 2009. It is also of a very similar size, having a thermal rating of

110MWth, against the proposed sites 104MWth.

More information is provided within the BATC appraisal, but a summary of key points is noted here:

Table 4. Reference Plant Characteristics Applicable to ERP7

Key Area Commentary

Process design and control. The plant will be controlled by A DCS / SCADA system

that take information from instrumentation plant wide.

Control loops within the program monitor all the

essential parameters and control the process in real

time.

Emission control equipment design and

control.

The emissions control equipment is described

elsewhere in this report, but follows standard principles

to ensure that reagent use is optimised, especially

when using a recirculation system of reagents to

improve the efficiency of use. Monitoring of factors

such as pressure drop across the fabric filter as well as

feedback from the CEMS system are all important to

reduce operational costs.

Emission monitoring with real-time

feedback to the controls of the process.

The CEMS system continuously monitors the

emissions leaving the stack and is a key indicator for

the emissions control equipment. An example would

be the direct link between ammonia injection for NOx

control. The first element for control of NOx is the

combustion control system which operates to make the

combustion process as efficient as possible. However,

the NOx levels will always need monitoring and

additional control implemented. By monitoring the NOx

level from the CEMS it can be identified if reagent

needs to be added to reduce the NOx levels further and

by monitoring other parameters can determine the

optimal level of addition.

Arrangements for the receipt of waste. The arrangements for the receipt of waste for the

reference project have to be in line with European

requirements, ensuring that any received waste,

including RDF, is clearly identified for what it is, who is

the producer and where it is going. The management

of materials on site, from receipt, inspections and

sampling, is noted within the Mt Piper Energy Recovery

Project RDF Feedstock Report by Ricardo.

Management of residues from the energy

recovery process.

Residues from the FGC plant are treated as hazardous

waste and much work has been carried out to identify

whether these can be used in block manufacture as an

example to achieve “End of Waste” status in the EU.

Bottom ash is processed and supplied into the

7 Parameters noted in Table 4 are common to the reference facility and the proposals for the ERP




aggregates market as an inert material rather than

disposed of as a waste. In Australia we understand that

this market is yet undeveloped but has potential to

recover this material in a similar way.

5.3 Technical Criteria Table 1 below identifies the Technical Criteria from the NSW Energy from Waste Policy and confirms

whether the reference plant meets the requirements of the policy.

Table 5: Technical Criteria

Technical criteria: Proposed Plant Reference Plant

Meet 850°C for at least 2

seconds in the combustion

chamber [equivalent to the

European Waste Incineration

Directive] or 1100°C for 2

seconds if the waste contains

more than 1% of halogenated

organic substances, expressed

as chlorine.

Yes. The proposed plant has

been selected to meet this

requirement.

Yes. The plant achieves this

requirement.

Meet or exceed the Group 6

emission standards in the

POEO Act [Ricardo assumes

that the limits for ‘general

activities and plant’ apply]

(solid particles 50 mg/m3; NOx

350 mg/m3; SOx 100 mg/m3;

H2S 5 mg/m3; HF 50 mg/m3; Cl

200 mg/m3; VOCs 40 mg/m3 or

CO 125 mg/m3; HCL 100

mg/m3; Cd or Hg 0.2 mg/m3;

dioxins or furans 0.1 ng/m3; type

Yes. The proposed plant will be

able to achieve the emissions

limits stated in European

Directive 2010/75/EU, the

Industrial Emissions Directive

which has more stringent

requirements for some

parameters than NSW set limits.

The plant operates to the

requirements of the Waste

Incineration Directive (WID),

the forerunner of the

Industrial Emissions

Directive.





1 (Sb, As, Cd, Pb, Hg) and type

2 (Be, Cr, Co, Mn, Ni, Se, Sn,

V) substances 1 mg/m3; smoke

Ringelmann 1 or 20% opacity.

Continuous measurements of

NOx, CO, particulates, total

organic compounds, HCL, HF

and SO2 and available in real

time to the EPA, plus

combustion temperature,

pressure and temperature in

stack, oxygen concentration and

water vapour in exhaust gas.

Continuous monitoring of the flue

gas at the stack is available

within the DCS. Subject to

providing a secure portal this

data will be made available to the

EPA.

Continuous monitoring of the

flue gas by a CEMS system

is in place.

It is not a requirement of the regulator to have online access to these readings, a public website is available with summary data8

Proof of performance trials as

part of the licence conditions to

demonstrate compliance with

emissions limits and

subsequently twice-yearly

measurements of heavy metals,

PAHs, chlorinated dioxins and

furans, and all to be subject to

continuous monitoring if and

when appropriate measurement

techniques are available.

Regular testing will be carried out

and sample points fitted at

appropriate locations on the flue

gas ductwork and stack to

facilitate the taking of those

measurements.

A regular monitoring regime

is required by the regulators

and it is understood that this

takes place at similar

intervals.

Total organic carbon (TOC) or

loss on ignition (LOI) content of

the slag and bottom ashes must

not be greater than 3% or 5%

(dry weight) respectively.

The proposed plant will be

including this as standard within

its design.

No specific information

provided to Ricardo, but this

is a standard parameter that

has been in place across

plants for a long time.

Waste feed interlocks to prevent

feeding when required

temperature has not been

reached.

The proposed plant will be

including this as standard within

its design.

This is a requirement of the

regulations and will be fitted.

This is a common

requirement on Energy from

Waste plants since the

introduction of WID.

Air quality impact assessment

must be undertaken in

accordance with the Approved

Methods for the Modelling and

Assessment of Air Pollutants in

NSW.

An Air quality Impact Assessment

has been carried out for the

facility.

A full air quality impact

assessment in accordance

with local requirements was

undertaken for the facility.

8 https://xn--ikw-rdersdorf-0ob.de/emissionswerte.htm





Thermal efficiency criteria:

Plants that do not recover

energy are outside the scope of

the Policy.

Not applicable. Not applicable.

At least 25% of energy will be

captured as electricity (or an

equivalent level of recovery for

facilities generating heat alone).

It is anticipated that

approximately 30MWe will be

attributed to the steam provided

by the facility. Performance

modelling of the scheme has

provided an indicative figure of

29% for overall energy recovery,

a significant step above the

Policy threshold level.

Performance figures from

Rudersdorf indicate that the

efficiency of the process is

around 30%.

Any heat must be demonstrated

to be recovered as far as

practicable.

The facility will supply the

recovered heat to the Mt Piper

Unit 2 in the form of superheated

steam for the generation of

electricity.

There is some heat offtake

from the process, supplying

local industrial consumers.




6 Assessment against BATC

The IED specifies that a BATC review is considered to be a process whereby site-specific BAT is

determined with reference to relevant BATC. A BATC document is defined in the IED as a document

containing the parts of a BREF laying down the conclusions on best available techniques. In basic

terms the BATC will describe the issues to be considered and the expected performance levels of an

installation; it is then for the operator to demonstrate and ensure that the installation can meet these

performance levels.

BATC have a key role in the review process as their publication is the reference for setting permit

conditions.

BAT 1. In order to improve the overall environmental performance, BAT is to elaborate and

implement an environmental management system (EMS).

Compliant due to the following:

The Operator is experienced in the development and implementation of the necessary procedures

under an Environmental Management System (EMS) and have already put in place a certified system

for the existing Mt Piper installation. The nature of the different core activities means that for clarity the

ERP will not be incorporated into the wider Mt Piper EMS, but instead will have its own procedures and

systems in place and will seek to implement a certified ISO14001 EMS as soon as practicable.

The procedures to be put in place to implement the Environmental Policy will be developed as part of

the ongoing review of the operations throughout the design and construction of the project. This will

ensure that a robust and viable set of procedures can developed that are effective and achievable at

an early stage. The ERP has been fully assessed through the Environmental Impact Statement (EIS)

process to identify areas in which there is potential for any environmental risks to be present and these

have been identified for incorporation into the emergency planning for the site.

In operation, the plant will be controlled by a DCS/SCADA based system that will allow monitoring of

all systems ensuring effective and efficient operation of the plant. The system will provide for logging

and monitoring of key process parameters that can be used to seek resolution to any issues that arise

on the plant.

The ERP will be subject to its own safety permitting scheme, ensuring that any operations and

maintenance work is carried out in a safe manner and that “safety from the system” can be achieved

prior to any normal maintenance activity.

Maintenance procedures shall be put in place that will provide for condition monitoring and Planned

Preventative Maintenance (PPM).

In order to ensure that these, and other monitoring requirements are maintained, the Operator will be

subject to a system of both Internal and External audits that will serve to identify any ways in which the

EMS and other systems can be improved.

The EMS will also incorporate procedures that relate to the monitoring of residues and fugitive

emissions generated from the process as well as emissions to air and water, for example bottom ash

and odour.

These will be subject to appropriate plan documents that will be put in place as part of the EMS to

ensure that adequate controls are present and applied to minimise any impact of the plant.

With any facility, it is important that the decommissioning of the plant is covered within the construction

phase, to ensure that the plant can be safely taken out of service at the end of its useful life. As such

a Decommissioning Plan will be included in the EMS, covering key aspects of work that will be required.

Note that at this time this will be a high-level document in accordance with any local requirements.




BAT 2. BAT is to determine either the gross electrical efficiency, the gross energy efficiency, or

the boiler efficiency of the incineration plant as a whole or of all the relevant parts of the

incineration plant.


The ERP will be supplying steam into the reheat cycle of the Mt Piper unit and therefore electrical

efficiency is not able to be monitored directly. Boiler Efficiency will therefore be used as an indicator of

the plant’s performance.

The operational efficiency of the plant will be monitored on a continuous basis through the DCS, but a

formal test would be required on a periodic basis to validate this.

A full load test will need to be carried out taking into account the potential variation in Calorific Value of

the RDF, and the net energy supplied to Mt Piper.

It is anticipated that due to the arrangement with Steam being supplied into the existing unit that

correspondingly higher electrical generation per unit of steam can be achieved.

BAT 3. BAT is to monitor key process parameters relevant for emissions to air and water.


A Continuous Emissions Monitoring System (CEMS) will be installed on the plant located in the stack

or flue gas ductwork.

Sensors within the ductwork will allow the measurement of pressure and temperature and flow rate will

be monitored by using an ultrasonic device.

The parameters will be monitored through the DCS and should there be a significant variation alarms

will be raised to alert the operator.

Any waste water from the plant is normally stored for reuse within the plant and will be monitored for

pH, temperature and production rate.

If there are any other residues, these will also be similarly monitored and treated prior to disposal in

accordance with the relevant discharge consents.

BAT 4. BAT is to monitor channelled emissions to air with at least the frequency given below

and in accordance with EN standards. If EN standards are not available, BAT is to use ISO,

national or other international standards that ensure the provision of data of an equivalent

scientific quality.


Channelled emissions to air relate to the release of emissions from the stack as the single point source

emission from the ERP.

There is potential for (fugitive) emission from other areas of the plant in the form of noise, odour and

dust, though these are subject to local controls as discussed elsewhere in this document.

Channelled emissions to air shall be monitored through the use of an appropriately certified Continuous

Emissions Monitoring System (CEMS) that will be installed in the stack or flue gas ductwork after all

flue gas treatment operations.

This will provide for regular monitoring in accordance with the Industrial Emissions Directive

(2010/75/EU).

In addition, there are some determinants that are to be monitored on a periodic basis and sampling

ports to meet the requirements of the monitoring agency are to be installed on the plant.

Any sampling point needs to be in a location that can ensure that representative samples can be taken

and that a stable gas flow condition has been achieved.




BAT 5. BAT is to appropriately monitor channelled emissions to air from the incineration plant

during OTNOC.


Monitoring of the plant during Other Than Normal Operating Conditions (OTNOC) will be carried out

using the direct CEMS instrumentation.

Emissions during start up and shutdown will be estimated as the start-up conditions will not generally

provide for adequately stable conditions for monitoring.

BAT 6. BAT is to monitor emissions to water from FGC and/or bottom ash treatment with at least

the frequency given below and in accordance with EN standards. If EN standards are not

available, BAT is to use ISO, national or other international standards that ensure the provision

of data of an equivalent scientific quality.

Not Applicable.

Waste water from the processes on site will normally be reused within the site, for example bottom ash

quenching, and therefore there will not be any releases from the site.

Should there be a requirement for waste water to be released from site, it would be carried out under a

defined trade discharge consent or tankered from site for disposal via a facility licensed to receive that

waste.

BAT 7. BAT is to monitor the content of unburnt substances in slags and bottom ashes at the

incineration plant with at least the frequency given below and in accordance with EN standards.

As part of the EMS, the plant will implement monitoring procedures to review the quality of bottom ash

produced.

BAT 8. For the incineration of hazardous waste containing POPs, BAT is to determine the POP

content in the output streams (e.g. slags and bottom ashes, flue-gas, waste water) after the

commissioning of the incineration plant and after each change that may significantly affect the

POP content in the output streams.

Not applicable.

The Mt Piper ERP is not going to be processing Hazardous wastes, and therefore this requirement is

not applicable.

BAT 9. In order to improve the overall environmental performance of the incineration plant by

waste stream management (see BAT 1).

Please also see Mt Piper Energy Recovery Project RDF Feedstock Report - Ricardo

The Plant has been designed to accept an RDF that has bene specifically prepared to meet the

requirements of the combustion plant. The RDF specification is derived from municipal and Industrial /

Commercial (I&C) waste streams with a target CV of and waste (commercial waste which is similar in

composition to municipal waste) with a calorific value of 15MJ/kg. Over time it is likely with changing

lifestyles through regulation it is possible that the CV of the RDF will change, but the operating envelope

(aka “firing diagram”) of the plant allows for operation between 9 – 18MJ/kg giving significant ongoing

flexibility.

Prior to delivery to the plant, the specification for the RDF will be clearly communicated to the providers,

with regular audit and checks carried out to ensure that the RDF is suitable for processing at the plant.

Particular reference will be made to those criteria that are important for the management of

environmental issues on site, such as the fraction size of the RDF (large items may cause blockages in

the feed system or in the ash discharge of the combustion unit) and the component waste streams

being processed (to ensure that the RDF comprises non-hazardous material) to create the RDF.




Procedures will be in place for material received at the plant. Visual inspections of bulk compacted

loads will take place on arrival against any potential fire risk, and on depositing in the bunker for any

non-compliances in material. Occasional loads will be deposited on the floor for inspection and

sampling prior to pushing into the bunker.

Samples will also be taken to check the calorific value, moisture content and other characteristics of the

waste on the basis of individual suppliers to the plant.

As the material is all RDF, there is no need for specific segregation of material and once deposited in

the bunker it will become mixed and blended with other material already in place. This creates a

homogenous mix of material for feed into the combustion, aiding the plants ability to maintain stable

combustion conditions.

Whilst there may be a storage area identified for bales, the preference is that baled material will be

opened and delivered to the bunker as soon as practicable. In the event that storage is required, this

will be managed on a first in / first out basis with clear labelling to identify the bales

BAT 10. In order to improve the overall environmental performance of the bottom ash treatment

plant, BAT is to include output quality management features in the EMS (see BAT 1).


The bottom ash from the ERP will not have any appreciable metal content as this will have been

extracted as part of the fuel preparation (RDF) process.

The bottom ash will be monitored in order to ensure that the necessary requirements (BAT 7) are met

prior to its transport and storage within a landfill.

Within the UK and Europe, the market for bottom ash as a material is well developed due to the number

of facilities and the volume of material generated. In Australia, this market, and the associated

regulatory environment, is yet undeveloped and so, until such time as it becomes viable to recover it, it

will be stored in a dedicated cell.

BAT 11. In order to improve the overall environmental performance of the incineration plant,

BAT is to monitor the waste deliveries as part of the waste acceptance procedures (see BAT 9

c) including, depending on the risk posed by the incoming waste.


The ERP will only be receiving RDF that has been processed from Municipal waste and other similar

non-hazardous waste streams. Therefore, only the first category of this section is relevant to this project.

Please see BAT 9 above also. The RDF being delivered to the site will be in either baled or bulk

compacted form and as such will be delivered in different ways.

Bales

Delivery of bales that are being immediately processed will be batch weighed as they are delivered to

site over the weighbridge. Any that are going into storage will be noted to ensure that accurate stock

records can be maintained.

Visual inspection of the bales to ensure their integrity will be carried out, particularly where the bales

are going to be stored. The internal content of bales cannot be checked until it has been passed through

the bale breaker / shredder on feeding into the bunker. However, appropriate quality checks and audits

at the producer sites will be carried out to ensure consistency is achieved.

This will also include periodic sampling and/or the consideration of an analyser within the RDF process

line to confirm the typical energy content and other key composition parameters of the material.




Bulk Compacted

Bulk compacted material will also be weighed as it enters the site and the producer sites will also be

subject to regular review to ensure that the material is appropriate for processing by the ERP.

A visual inspection of each load prior to tipping may be carried out, though this will only be relatively

cursory for issues such as large items, or serious issues such as a potential hot load (i.e. visible signs

of smouldering).

Periodic samples of the RDF being tipped at the site will be taken on a supplier and load frequency

basis so that key parameters such as energy content can be monitored, thereby ensuring a consistent

feed into the plant.

BAT 12. In order to reduce the environmental risks associated with the reception, handling and

storage of waste.


RDF coming into the site will either come in bulk compacted or in baled form. Wrapped bales of RDF

are, by their nature, sealed to prevent any release of liquid effluent/leachate and on arrival will be

processed through a large shredder and discharged into a large concrete storage bunker. Use of a

concrete storage bunker is common practice throughout the vast majority of EFW plants worldwide and

provides a sealed unit that prevents leachate from the fuel seeping into the local environment. It also

means that groundwater cannot ingress into the fuel causing combustion problems.

In general, leachate in the fuel is reabsorbed and processed through the plant.

The bunker area is fully enclosed to prevent odour emissions, wind-blown litter and dust emissions from

the site and any excessive bunker leachate is extracted and treated.

The bunker will have a design capacity of 4.5 days, which is based on the requirement to continuously

operate through periods when no deliveries are being accepted at the plant. At this level there is little

risk of spontaneous combustion of the stockpile. For the majority of the time the storage bunker will not

be full (perhaps operating around 50% capacity), and the operators will make reasonable efforts to

process “older” RDF first. There is also the capability to stack RDF further during short term plant

outages for continuity of deliveries.

The plant operator would liaise with waste suppliers to control deliveries as set out in the Operation and

Maintenance plan which would be developed during the plant design and construction phase

BAT 13. In order to reduce the environmental risk associated with the storage and handling of

clinical waste.

Not applicable.

BAT 14. In order to improve the overall environmental performance of the incineration of waste,

to reduce the content of unburnt substances in slags and bottom ashes, and to reduce

emissions to air from the incineration of waste, BAT is to use an appropriate combination of the

techniques given below.


Use of an RDF fuel provides for some relative consistency in feedstock relative to an unprocessed

Municipal Waste. However, some fluctuations in quality can arise depending on its source and therefore

mixing and blending operations with the bunker crane are a crucial part of the process to ensure good

operation of the plant.

At regular intervals, when the crane is not involved in feeding the hopper, selective mixing of the bunker

material will take place, allowing not only for consistency of feed but also for the operator to spot any

larger items of waste within the RDF that would present a risk to the process.




The combustion control system incorporated as part of the DCS also provides for online adjustment of

primary and secondary combustion air flows and fuel feed-rate to ensure that the combustion process

is optimised.

BAT 15. In order to improve the overall environmental performance of the incineration plant and

to reduce emissions to air, BAT is to set up and implement procedures for the adjustment of the

plant’s settings, e.g. through the advanced control system (see description in Section 2.1), as

and when needed and practicable, based on the characterisation and control of the waste (see

BAT 11).


The ERP will be controlled via a Distributed Control System (DCS). This allows for the operators to

monitor and control all aspects of the process from the control room. It will incorporate various

automatic control set points for the process that will allow the DCS to monitor and adjust key parameters

such that the overall process efficiency is maintained.

The advanced combustion control system is incorporated within the DCS and therefore meets this

requirement.

BAT 16. In order to improve the overall environmental performance of the incineration plant and

to reduce emissions to air, BAT is to set up and implement operational procedures (e.g.

organisation of the supply chain, continuous rather than batch operation) to limit as far as

practicable shutdown and start-up operations.


The ERP will maintain strong links with its fuel supply chain, as much as to ensure that the RDF being

received is of a consistent quality as to ensure security and regularity of supply. By incorporating a 4.5

day storage bunker as well as bale storage facility, the plant can continue operating even over some

days of breakdown of the supply chain, allowing any issues arising to be managed. It is standard

practice across Waste to Energy plants of this type to have a bunker sized at this capacity.

The core principle of operation for the ERP, and other energy from waste facilities of this type, is to

operate as “base load”, i.e. to be operating continuously except for periods of planned maintenance.

BAT 17. In order to reduce emissions to air and, where relevant, to water from the incineration

plant, BAT is to ensure that the FGC system and the waste water treatment plant are

appropriately designed (e.g. considering the maximum flow rate and pollutant concentrations),

operated within their design range, and maintained so as to ensure optimal availability.


At this stage of the design the techniques proposed to control emissions are broadly categorised into

two key areas:

1. Control of NOx.

2. Absorption of Pollutants.

The selection of technologies to be used do not require waste water treatment as a “Dry” FGC system

is proposed rather than ‘Wet’ scrubbing systems which have several processing stages.

NOx control will utilise two key methodologies. Flue Gas Recirculation, where a proportion of the flue

gas is recirculated back into the combustion system, and Selective Non-Catalytic Reaction (SNCR).

The SNCR process entails ammonia water, or urea, injection in the upper part of the combustion

chamber of the furnace where gasses are at a temperature of 850-950°C. These temperatures are

suitable for ammonia to react with nitrogen oxide (NO) and nitrous oxide (NO2).




There is potential for an emission of ammonia from the stack using SNCR, which is termed “ammonia

Slip”. However, this is a useful parameter as it can be continuously monitored and kept to a minimum

level, therefore allowing the process to operate efficiently.

A dry absorption systems is where the chlorine and sulphur content of the waste leaves the facility as

a dry product, and no wastewater is produced. This system is commonly employed in EfW plants. Lime

is the most commonly used reagent in a dry system, noting that sodium bicarbonate-based systems

are also sometimes specified.

BAT 18. In order to reduce the frequency of the occurrence of OTNOC and to reduce emissions

to air and, where relevant, to water from the incineration plant during OTNOC, BAT is to set up

and implement a risk-based OTNOC management plan as part of the environmental management

system (see BAT 1).


As part of the design process critical failure items will be identified and, where appropriate, redundancy

included within the design.

The core principle of the ERP will be to maintain the plant effectively to ensure that there are limited

opportunities for OTNOC to apply and procedures will be in place to coordinate and control the

maintenance of the plant. By controlling and monitoring the plant through the DCS, many situations

can be identified early and a shutdown of the plant avoided.

A key component of the design is to ensure that the plant operates to achieve the required post

combustion residence requirements of 850°C for 2 seconds. Should the DCS (or operator) identify that

the operating temperatures are dropping, then the auxiliary start up burners will be initiated to keep the

plant operating at its required temperatures.

Should power to the site be lost for any reason, it is normal that an emergency / standby generator be

employed in order to provide sufficient power that the site can shut down in a controlled fashion.

Through the design phase the potential for secure power supplies to be provided from the existing

network (Mt Piper Power Station) may also be considered as an alternative.

At all times the CEMS system will be operational and will ensure that the emissions to air are monitored

in accordance with the requirements of the EPA.

BAT 19. In order to increase the resource efficiency of the incineration plant, BAT is to use a

heat recovery boiler.


The ERP will recover energy in the form of steam through a boiler. This steam will be provided to the

Mt Piper Power Station at a pressure and temperature to be introduced into the existing “reheat” steam

circuits. The pressure and temperature of this steam circuit is typical of Energy from Waste boiler

conditions, as being a temperature, at which fouling and corrosion of the boiler can be minimised

providing for economic operation.

BAT 20. In order to increase the energy efficiency of the incineration plant, BAT is to use an

appropriate combination of the techniques given below.


The ERP will use a variety of techniques in order to maintain high levels of energy efficiency. As is the norm for these plants, the entire combustion system and boiler will be well insulated and

incorporate the use of heat recovery tubes in the membrane walls of the combustion chamber and

immediately adjacent gas path.

Combustion air is carefully controlled through the control system to maintain optimum combustion

conditions and defines the amount of draught required.




The boiler will incorporate a number of tube bundles as part of the heat recovery system, including

evaporator, superheater and economiser tubing sections and these will be positioned to ensure that

good quality steam can be produced at the same time as ensuring a rapid temperature drop of the flue

gas through critical temperature bands to prevent the reformation of dioxins and furans via de Novo

Synthesis.

The steam conditions have been selected to meet the requirements of the adjacent power station, and

by operating in this steam supply mode allows for a greater electricity yield per unit of ERP steam than

by fitting a dedicated steam turbine.

The use of heat exchangers beyond the economiser within the system, e.g. after the FGC system, is

restricted in many plants as the flue gas temperature at the exhaust of the stack needs to have sufficient

temperature to encourage plume buoyancy and dispersion of the flue gas. In addition, the opportunity

for recovering this heat into the cycle remains very low as other sources of waste heat are already

utilised in order to preheat combustion air, for example.

This is carried out by using the cooling system of the grate to preheat air and, in some circumstances,

feed water. Feedwater will be provided from the Mt Piper power station and therefore the requirement

to preheat raw water is negligible.

The ERP plant design incorporates good practice techniques as can be seen on the reference plant

and will have a high efficiency of energy recovery to steam.

BAT 21. In order to prevent or reduce diffuse emissions from the incineration plant, including

odour emissions.


Odour from the plant will be managed through the implementation of an Odour Management Plan, to

be included within the EMS.

In general, when the plant is operational air for combustion will be drawn from the area above the waste

storage bunker, bringing that area of the building under a slight negative pressure and therefore

reducing the potential for release of odour. Limiting the openings into the building through door

management procedures also improves this control.

Material in the bunker will be processed in reasonable time frames from receipt and therefore will not

be allowed to remain in the bunker for long periods of time increasing their potential to emit odorous

compounds.

At times when the plant is offline, the bunker area will be closed and a bunker standstill odour extraction

system will mitigate any emission of odours.

Any other waste stored in bales will be sealed preventing any release of odour.

BAT 22. In order to prevent diffuse emissions of volatile compounds from the handling of

gaseous and liquid wastes that are odorous and/or prone to releasing volatile substances at

incineration plants, BAT is to introduce them into the furnace by direct feeding.

Not applicable due to the nature of the acceptable wastes for the ERP.

BAT 23. In order to prevent or reduce diffuse dust emissions to air from the treatment of slags

and bottom ashes, BAT is to include in the environmental management system (see BAT 1).

The bottom ash will be deposited on site in a controlled fashion with water addition to minimise dust

production during transport and placement in the ash repository.

Due to metals being removed from the RDF pre-combustion, no treatment or separation processes are

proposed at this time.




BAT 24. In order to prevent or reduce diffuse dust emissions to air from the treatment of slags

and bottom ashes, BAT is to use an appropriate combination of the techniques given below.

Not applicable, as bottom ash treatment processes do not form part of this facility – see BAT23.

BAT 25. In order to reduce channelled emissions to air of dust, metals and metalloids from the

incineration of waste.


A dry system will be used that allows for the injection of hydrated lime and activated carbon for the

control of acid gases and dioxins, mercury and other heavy metals respectively. This will be separated

from the gas steam by means of a bag filter.

BAT 26. In order to reduce channelled dust emissions to air from the enclosed treatment of slags

and bottom ashes with extraction of air, BAT is to treat the extracted air with a bag filter.

Not applicable as bottom ash treatment processes are not part of the ERP.

BAT 27. In order to reduce channelled emissions of HCl, HF and SO2 to air from the incineration

of waste.


The ERP will incorporate a system for the injection of Hydrated Lime within the gas path. The ERP will

use a dry Sorbent Injection system of hydrated lime and activated carbon for the control of acid gases

and dioxins, mercury and other heavy metals respectively. This will be separated from the gas steam

by means of a bag filter.

BAT 28. In order to reduce channelled peak emissions of HCl, HF and SO2 to air from the

incineration of waste while limiting the consumption of reagents and the amount of residues

generated from dry sorbent injection and semi-wet absorbers


The FGC system will use online monitoring from the CEMS to control the operation of the fabric filter

and dosing rates.

The fabric filter operates in its most effective mode when it has a collection of material over its service,

decreasing its effective pore size yet also providing increased residence time for acid gas control.

However, the deposition of material also creates an increased pressure drop over the system and

therefore requires cleaning via a reverse pulse air jet.

The system collects the ash in the bottom of the hopper and a proportion of the material is recirculated

back to the injection point in the gas path. This means that the efficiency of FGC using hydrated lime

and activated carbon is increased yet the consumption of the reagents is much lower.

BAT 29. In order to reduce channelled NOx emissions to air while limiting the emissions of CO

and N2O from the incineration of waste and the emissions of NH3 from the use of SNCR and/or

SCR.


A combination of the techniques will be listed, including:

Optimisation of the incineration process – The plant and its combustion system will be controlled by a

DCS, monitoring the combustion process.

Flue Gas Recirculation – This will be further considered in the detailed design phase for the further

reduction in NOx levels.

Selective non-Catalytic Reduction (SNCR) – This is a preferred option for the control of NOx, providing

easy application in the use of Urea or Ammonium Hydroxide.




Optimisation of the SNCR System – All the FGC systems will be monitored continuously through the

DCS.

With the selection of the above processes, there is no requirement to use SCR, Catalytic Filter Bags or

Wet Scrubber.

BAT 30. In order to reduce channelled emissions to air of organic compounds including PCDD/F

(dioxins and furans) and PCBs from the incineration of waste.


Optimisation of the incineration process – The plant and its combustion system will be controlled by a

DCS, monitoring the combustion process and thereby ensuring that the time / temperature requirements

(2 seconds at 850°C) for ensuring destruction of compounds are met.

In order to keep the boiler and its associated gas passes clear of significant build-up of dust, and to

ensure that it operates efficiently as a heat transfer surface, the ERP will be equipped with online

cleaning sprays and soot blowers at different points in the gas path. These online measures have been

employed on many plants and reduce the requirement to come offline for cleaning.

The boiler will incorporate a number of tube bundles as part of the heat recovery system, including

evaporator, superheater and economiser tubing sections and these will be positioned to ensure that

good quality steam can be produced at the same time as ensuring a rapid temperature drop of the flue

gas through critical temperature bands to prevent the reformation of dioxins and furans via de Novo

synthesis.

By ensuring the destruction and reducing the potential for reforming of dioxins and furans compounds

the residual quantities are controlled by the injection of sorbents into the gas stream.

The ERP will use a dry Sorbent Injection system of hydrated lime and activated carbon for the control

of acid gases and dioxins, mercury and other heavy metals respectively. This will be separated from

the gas steam by means of a bag filter.

BAT 31. In order to reduce channelled mercury emissions to air (including mercury emission

peaks) from the incineration of waste.

Compliant for the following reasons:

The ERP will use a dry Sorbent Injection system of hydrated lime and activated carbon for the control

of acid gases and dioxins, mercury and other heavy metals respectively. This will be separated from

the gas steam by means of a bag filter.

BAT 32. In order to prevent the contamination of uncontaminated water, to reduce emissions to

water, and to increase resource efficiency, BAT is to segregate waste water streams and to treat

them separately, depending on their characteristics.

Not applicable as there are no waste water streams from the plant.

BAT 33. In order to reduce water usage and to prevent or reduce the generation of waste water

from the incineration plant, BAT is to use one or a combination of the techniques given below.


The FGC equipment is a dry sorbent injection process and therefore does not generate an aqueous

effluent. Any process derived liquids are reused on site, for example in the bottom ash quench, and the

process overall is a net consumer of water.




BAT 34. In order to reduce emissions to water from FGC and/or from the storage and treatment

of slags and bottom ashes, BAT is to use an appropriate combination of the techniques given

below, and to use secondary techniques as close as possible to the source in order to avoid

dilution.


The FGC equipment is a dry sorbent injection process and therefore does not generate an aqueous

effluent. Any process derived liquids are reused on site, for example in the bottom ash quench, and

the process overall is a net consumer of water.

BAT 35. In order to increase resource efficiency, BAT is to handle and treat bottom ashes

separately from FGC residues

Compliant as both streams will be handled separately.

BAT 36. In order to increase resource efficiency for the treatment of slags and bottom ashes,

BAT is to use an appropriate combination of the techniques given below based on a risk

assessment depending on the hazardous properties of the slags and bottom ashes.

Not applicable, as bottom ash treatment processes do not form part of this facility.

BAT 37. In order to prevent or, where that is not practicable, to reduce noise emissions, BAT is

to use one or a combination of the techniques given below.

The detailed design phase will identify areas in which there are noise generating plant and seek to

enclose them where necessary. The majority of plant will be enclosed within the building, and therefore

any noise generated is attenuated by the building.

On the site of the ERP, with the close proximity of the Mt Piper Power Station, the noise levels for the

plant are not believed to be critical contributors to the surrounding environment.




7 Commentary and Conclusions

Following the review and assessment of the technology proposals provided, Ricardo concludes that the

technology proposed for the Mt Piper Energy Recovery Project represents the Best Available Technique

in accordance with the EU Reference Document9.

In reviewing the technology proposals Ricardo has also reviewed information pertaining to an existing

power plant at Rudersdorf. This EfW plant has many similarities to the proposed scheme, including

similar steam temperature (Rudersdorf is a higher-pressure boiler but it generates steam at 400°C as

proposed at the ERP), FGC train and, most importantly, operates on an RDF feedstock. The plant has

operated for many years on RDF and through its high efficiency of operation meets the requirements

of an R1 “Recovery” process.

Whilst this reference facility is important due to its many similarities, the technologies proposed at all

stages of the ERP have many references. The technologies proposed for the ERP are not novel and

have been applied on many projects worldwide and operate effectively on different types of fuel that

exhibit much more variability than the RDF fuel proposed to be fed to the ERP.

Ricardo concludes that the selected technology and techniques are capable of handling and processing

the RDF, along with its inherent variability.

In relation to heat recovery, the performance of the plant and use of the steam within the existing power

plant represents the option to gain most efficiency from the steam produced. On this basis Ricardo

considers that the conceptual design includes heat recovery to the extent practicable.

9 Best Available Techniques Reference Document for Waste Incineration, European Commission Joint Research

Centre Directorate B European IPPC Bureau, December 2018,

http://eippcb.jrc.ec.europa.eu/reference/BREF/WI/WI_BREF_FD_Black_Watermark.pdf, (accessed July 2019)

http://eippcb.jrc.ec.europa.eu/reference/BREF/WI/WI_BREF_FD_Black_Watermark.pdf

The Gemini Building Fermi Avenue Harwell Didcot Oxfordshire OX11 0QR United Kingdom

t: +44 (0)1235 753000 e: [email protected]

ee.ricardo.com

appendix e best available techniques assessment

Documents