Emerging Best Energy Practices in Seshasayee Paper related to

Cross –sector application

Dr T.G.Sundara Raman Seshasayee Paper and Boards Limited

2nd National Workshop for Promoting Energy efficient & Cleaner Production for Sustainable Industrial growth

BEE/IIP/BHC

New Delhi 9th March 2018

ENERGY SECTORS - PAT A. Thermal Power plants

B. Iron & Steel

C. Cement

D. Fertilizer

E. Aluminium

F. Pulp & Paper

G. Textile

H. Chlor-Alkali

I. Petroleum Refinery

J. Sugar

Independent Captive Power Plants

Cross – Sector Energy Scheme Exchange

S

P

B

Circular /Linear Economy : Cross-Sector

WASTE/RESOURCE Management

Plant Waste

Linear

Economy

---------------------

Reduction

Circular

Economy

-----------------------

Elevation to

Resource

REPLICATION

Within the

Plant

Within the

Sector

Across the

Sector

Best Energy Practices for Replication in Other Industries [ Cross –Sector Application]

• Successfully Implemented Schemes A

• Schemes under Implementation B

• Emerging Schemes Planned for Implementation in near future C

SPB Unit : Erode

Best Energy Practices

•Successfully Implemented Schemes A

Multi-Sector Cascading from Waste {of Paper Sector} to Resource{ for Cement Sector}

CPP Coal fired Boiler Paper Mill

Waste Bottom/flyash

from Boiler

Bottom ash [ Low LOI] supplied to Cement Industry

Used as Clinker aggregate

Cement-Final Product

400 TPD

Ash : 4 %

LOI redn.from 12-14% to 6-8%

15 TPD

~10 TPD

Combustion effy incr. by 0.5%

AFBC Boiler [# 10 ] Air & Flue Gas Diagram

Waste to Energy Conversion

Boiler #10- LOI redn. in Bottom-flyash ----------------------------------------------------------------------------------------------------

•P.A. pressure reduced from 1400 to

1200 mmWC

LOI in Bottom-Flyash reduced from 12% to 8%

Combustion η incr.by : 0.4 to 0.5 %

Coal saving : 50 to 60 t/m

GHGE reduction: 750 to 900 tCO2e/yr

Easy disposal of FA to Cement mill

Equipment

Steam

Rate

TPH

Efficiency

%

Power

Consumption

Power

Savings

%

Daily

Power

Savings

in Units

Feed pump 90 60 15200 Basis Basis

HE BFP with

Lower

Disch.Head* 95 77 12000 21

3200-

3400

HP Chemical Recovery Boiler Feed Pump

8

* : Lower Discharge Head with Lower DP Control Valve in place

Spin-off Benefit: HPSteam : 6 TPD

Replication : All Sectors

Maximizing Cycle Efficiency with Waste heat recovery through

Exhaust steam Vacuum-Dryness fraction integration in 21MW Steam Turbo-Generator

Technology and Working of Innovation • In Steam turbo-generators related to exhaust

steam in condensing mode, the heat to power conversion ratio is invariably low [ poor low turbine heat rate] with the heat rejection- due to latent heat- from exhaust steam condensation to cooling water in closed cycle being of a very high order. The innovation concept focused on maintaining lower exhaust steam dryness [89% to 93 %] alongside conventional improved condenser vacuum in maximizing Power generation without additional energy intake.

• With around DF gain of over 1% from otherwise wasted exhaust steam , the electrical Power conversion realized is –

from 0.15/0.2 MW [ at lower condensing loads]

to 0.25/0.32 MW [ at higher condensing loads].

21 MW STG Exhaust steam Dryness

Fraction –Snap shot

Cross- Sector Replication

• Paper & Pulp Sector

• Industrial CPP & Thermal Power PlantsPlants.

.

Process condensate polishing

Waste heat recovery through PHE

Condensate polishing resin bed

ACF MB

ST

FWT

Process Hot / Condensate Tank

Filter

Polished Condensate

To Deaerators

PHEs Hot

Fluid

Process Condensate : 90°C to 40°C

DM Water Preheating : from 32°C

Heat Recovery : 4 MWt

CPU+ HRU - INTEGRATED WATER & ENERGY MANAGEMENT -BOILERS [CFB & CRB]

Replication : Sectors with HP Cogen Boilers

Green Power – Export

& LP steam- Process

Bagasse- Fuel in

HP Cogen

Cane Milling for Juice extraction

& Bagasse

Sugar cane to Ponni Sugar Mill

Lift Irrigation for Sugar-Cane

Growth

Little Green Power used for

lift irrigation

Waste Effluent to Renewable Energy

Cycle

Residual Waste: Minimal

Waste Effluent Discharge Eutrophication

Impact Reduction

Circular Economy

Treated waste water for Sugarcane irrigation Ponni

Sugars Bagasse (of SPB) fired in HP cogen

Generation of Green Power Green Power (0.5 MW) Export Replication : Paper-Sugar

Complex

Parameter Present Earlier

Heat Exchanger SHE Shell &

Tube

White liquor outlet

temperature

100-120 C 85-100 C

Hot white liquor

temperature [with

Fouling/Corrosive ]

140-145 C 120-125 C

LP steam saving 2 TPH Basis

Emission Reduction 2000 tCO2e Basis

Advanced Energy Scheme for Fouling Fluid

SPIRAL HEAT EXCHANGER Performance Feed-back- RDH Station

.

Replication: Sugar,PC& Fert.

Innovative WHR Schemes

Hot Air Dissipation in SPB

STG

Generator Air Cooler

HRU

RLK

Satellite Cooler

HRU

AC-CPP

Oil Cooler

HRU

First of its kind

Air Compressor - Heat Available for Recovery

To

tal p

ow

er

100% 90%

A

vl h

eat

5% heat from drive motor

13% heat from After cooler

76% heat from Oil cooler

2% heat inside the canopy

2% heat radiated through canopy

Oil & Lubricant Cooling through Ambient air but Hot Air is being discharged into atmosphere. Not utilized in Process

Replication : All Sectors

Waste Heat recovery- Schematic

Waste heat recovery

MB

ST

FWT

Oil Boiler Feed Water

To Deaerator

PHE

Screw Air

Compressor

INNOVATIVE PROJECT

Elgi Screw Air Compressor – Water cooled HRU Micro PHE

ECS –AC –HRU COMBINE-

RECOMMENDATIONS

• Waste heat from Air Compressor [AC] is gainfully converted to usable energy through Boiler Feed water heating

• Not only the new Air compressors need be fitted with integrated HRU, but also HRUs should be added to the existing energy guzzling AC to suit.

• Stage is set for recovering the heat from after-cooler.

CPP-Boiler 10

Sonic Horn – Performance Enhancement OF CFB-CPP

HP Coal Fired Boiler

SH coil kept clean

Steam saving

Dedusting of SH Coil Exterior

Superheater Coils

Replication : Sectors with Solid fuel fired Boilers

Best Energy Practices

•Schemes under Implementation

B

Paper Machine- Yankee Cylinder ECS through arresting Radiation heat loss

. State of the art Insulation of Dryer end

• Drying Cylinder Length : 3.65 m

• Radiation heat loss across DC ends: 8-10%

• Insulation of DC ends : Mattress containing special Ceramic long fibre

• Double layer insulation

• Steam saving est: 2 TPD

Spin-off Benefits

# Uniform DC surface temperature across entire length

# Product quality enhanced

# Operators comfort from heat of radiation

Replication :Sugar

CPP –CFB-Exhaust Flue Gas HRU

ESP

Flue Gas

exhaust –

Condensate HX

• TG Condensate heating : 10 °C

• FG Exit Temp. : 130-132 °C

• CPP-Cycle η enhanced

• Deaer. Steam con. redn: 15 TPD

• Emissio redn: 100 tCO2e/m

ID

Fan

Flue Gas

Flue Gas

Replication : Coal fired Boiler

Best Energy Practices

•Emerging Schemes Planned for Implementation in near future

C

CPP: 21 MW DEC STG - INNOVATIVE ECS

DM water switch related to heat recovery from Turbo-generator winding heat dissipation for increased Cycle efficiency

Demonstration successfully done . Getting Ready for Implementaton on a continuous basis

Proposal: DM water- instead of cooling tower circulation raw water- is to be supplied to generator air cooler and is returned to the Deaerator at a higher temperature, thereby reducing LP steam.

23

STEAM

TURBINE

DM WATER IN

DM WATER OUT

G

GENERATOR AIR COOLER

PLANNED

REPLICATION POTENTIAL : Steam turbines with condensing units related to Cogeneration can take advantage of the scheme through implementation . Concept can be suitably modified for Thermal Power plants by utilizing turbine condensate instead of DM water.

BENEFITS ESTIMATED: • Deaerator steam consumption redn: 12 TPD

• GHG emission redn :1100 tCO2e/annum • Fouling of generator air cooler tubes is avoided

• Enhanced winding temperature reduction.

Radiation Heat Recovery –Hot Air to Boiler water heating

.

Parameter Units Value

Radiation Heat

transfer from

RLK-SC Exterior

Mkcal/day 4 -5

SC Surface temp. °C 280-310

Feed water inlet

temp. to HRU

°C

60

GHGE Reduction tCO2e/yr 500

LP steam saving TPD ~ 7

WHRS Proposed to capture Radiation & Convection heat from Satellite Cooler [SC] exterior of Rotary Lime Kiln[FLS]. The surface temperature of the SC is around 310°C. HRU panel enclosing the existing Rotating Satellite Cooler unit shall be in place so as to capture the heat of radiation. This radiation heat shall be captured by the boiler feed water for preheating & then on led to storage tank of CRB [ Boiler # 11].

Replication Sector : Cement Plants

CONCLUSIONS

• SPB had led the way for Cross-sectoral Energy [Industry] schemes implementation with minor/no modification

• Unique Waste Energy Low grade Heat Recovery schemes successfully implemented/in pipe-line.

• As for the Paper & Pulp Sector & CPP/IPPs, the stated Energy schemes can straightaway be implemented in their plants.

• Circular Economy : Waste from One Sector is to be used as valued Resource in same/cross-sector

Paper & Pulp

Sugar Mill

Paper Mill

CPP

Cement Plant

SUN

CO2

Tree Farming

Effluent

Bagasse

Bottom

Ash

Pith

Cross-Sector Waste to Resource

Multi-Sector Cascading

The new concept envisaged and successfully implemented relates to – • Waste to conversion of multi-industrial sectors. • Waste from one sector serves as resource of other sector; • This in turn yields waste which in turn becomes the resource for third sector; • Finally the waste from this plant serves as resource for yet another sector

WAY FORWARD

• In similar fashion there should be transfer of Knowledge from other Sectors in terms of Advanced Energy schemes successfully implemented for gainful use of the receiving sector with little/no modification

• Through Cross-sector Knowledge exchange, the Energy Intensity as well as Emission reduction shall comfortably be achieved.

Clean , Green & Strong

Continuously strives for improving the 3 Es-

• Energy Conservation

• Environment Control &

• Emission Reduction

On a Sustained and Continuous basis

ECS Replication in Recovery Complex

Proposed Spiral Heat Exchanger In pipe-line for Implementation

.

Parameter WBL [14%con.]

Evap. Steam condensate

Inlet Temp. 90 67-68

Outlet temp. 82 78-80

Heat Exchange

1 Mkcal/h

LP steam saving

~60 TPD

Emission reduction

~4000 tCO2e/yr

Waste Heat Recovery from Energy efficient Air Compressor

Micro-PHE attached to Screw Air Compressor exhaust

Energy & Emission Gains

• Annual Energy saving : 800-900 t LP Steam

• Carbon Emission reduction : ~170-190 tCO2e/yr

Boiler feed water : 2 TPH Heating from 30 to 70 C

Heat Recovery : 0.075Mkcal/h