pilot and bench scale fuel characterisation service for ......cfbc technology with co2 capture the...

Pilot and bench scale fuel characterisation

service for plant investors

Toni Pikkarainen

Jyväskylä, 23rd September 2014

VTT Technical Research Centre of Finland

2

Content

Introduction to fluidized bed combustion

Development of fluidized bed combustion technology

Characterization services

Test rigs

Results

References

Case examples

Summary

3

COMBUSTION

GASIFICATION

PYROLYSIS

CATALYTIC PROCESSES

VTT’s Fluidized Bed Platform

There are nearly 100 professionals working at VTT around the fluidized bed technologies

All these areas share the common ”process heart” - fluidized bed

The main differences between processes are mostly related to the temperature levels and gas atmosphere

Process integrations, close co-operation with industry, excellent experimental capabilities

4 23/09/2014 4

Advantages of fluidized bed combustion technology

• Burn simultaneously various kind of fuels from coal to biomass and mixtures of different fuels

• Applicable for high moisture, high ash and high sulphur fuels Fuel flexibility

• In-furnace sulphur capture by limestone (no need for FGD unit down stream)

• Low NOx due to low and uniform combustion temperature (typically 800…900ºC) and air staging

Low emissions

• Unit size from small district heating plant ~ 1 MWth (BFB) to utility scale power production 800 MWe (CFB) Scalability

• Utility scale CFB (OT SC) about 42…45 % LHV efficiency (similar to PC)

• Uniform temperature/heat flux profile suitable for OT water/steam cycle High efficiency

• Potential to decrease the investment and operating costs by high O2 content in combustion gas

Flexi Burn oxy-CFB concept with CCS

5 23/09/2014 5

Development steps in

fluidized bed combustion

0

50

100

150

200

250

300

350

400

1976

Pilot Plant 0,05

Pihlava 5

Kauttua 20

Leykam 40

Tri-State 2 x 55

Kajaani 85

Vaski- luoto 125

Nova Scotia

180

Turow 235

MWe

1979 1981 1987 1987 1989

Year

1990 1993 1998

Alholmen

240

2001

Natural circulation

First OTSC CFB

Lagisza

460

2009 2010 2011

CIUDEN

30

VTT coordinated R&D project related to …

*

*

*

*

550

Build up of VTT’s first FB pilot

Four 550 MWe block

Samcheok Green Power

Project in Korea

Demonstration of

oxyfuel combustion

CIUDEN project

In Spain

* CFB800 Design

201x

6 23/09/2014 6

500

550

600

650

700

750

800

850

900

2001 2003 2005 2007 2009 2011

CO

2e

mis

sio

n [k

g/M

Wh

ele

ctr

icit

y]

Year

CFB COMBUSTORS

Compact drum boiler, 260 MWe

HIPE CFB

OTSC 460 MWe

CLEFCO

OTSC 460 MWe with biofuel

0

CFB800

OTSC 800 MWe

FLEXI BURN CFB

with CO2 capture

100% coal

80% coal

20% biomass

multifuel

design

BIOMAX

drum boiler with 100%

biofuel, 260 MWe

Unit Capacity (MWe)

0

100

200

300

400

500

600

1970 1975 1980 1985 1990 1995 2000 2005 2010

Start-Up Year

Pilot PlantOriental Chem

Lagisza

JEA

Turow 1

Vaskiluodon

Nova ScotiaTri-State

General Motors

800800 MWeUnit Capacity (MWe)

0

100

200

300

400

500

600

1970 1975 1980 1985 1990 1995 2000 2005 2010

Start-Up Year

Pilot PlantOriental Chem

Lagisza

JEA

Turow 1

Vaskiluodon

Nova ScotiaTri-State

General Motors

800800 MWe

O2GEN

2012-2015

Optimisation of Oxygen-based

CFBC Technology with CO2

capture

The project objective is to

demonstrate a significant (50%)

reduction the overall efficiency

penalty of CO2 capture into power

plants, from approximately 10 to 5

efficiency points

Development of CFB technology under EU

programs with VTT’s participation

7

Scaling up CFB’s (EU project HIPE CFB)

Scale up CFB from 300 to 460 MWe (first step)

Integrate the once through sliding pressure

steam cycle with large scale CFB combustion

Understanding of

Combustion profile, fuel and char reactivity

Material behaviour process

Boiler dynamics and boiler response times

Fuel/combustion air mixing process

Effect of increased lateral dimensions on mixing, combustion performance, temperature profiles and heat transfer

Design – furnace, superheaters, process components, material and construction issues

Lagisza 460 MWe, commissioned June 2009

First reference for Once Through CFB technology concept

World’s largest CFB in operation

8

Next step to scale up CFB - from 460 MWe to 800 MWe

(EU project CFB800)

In CFB800 project viable CFB plant design in size of 800 MWe

was developed.

The calculated net plant efficiency of the CFB800 was 45%

(600/620°C and 300/50 bar).

The water and steam side of the design is based on low mass

flux BENSON once-through technology.

A cost structure of the CFB800 concept was determined for the

complete power plant.

The design resulted in a furnace cross-section of 40 x 12 m,

and a furnace height of 50 m

9

Co-firing of biomass and coal in once through units,

nature of biomass vs. coal

(EU project CLEFCO)

The key issue is to understand multifuel operation

• combustion profiles

• temperature profiles

• emission formation and furnace heat transfer

For that testing was carried out in VTT’s

CFB pilot and Chalmers’ 12MW CFB boiler to analyse

ash and limestone fragmentation

• furnace solids loading

• particle size distributions

• furnace heat transfer- solids and fuel mixing in the furnace lower region

ash management possibilities for coal, and co-combustion of coal and biomass.

As a result development of combustion models and control strategy for

co-firing at OT CFB conditions

10 23/09/2014 10

Summary – fluidised bed combustion (FBC)

During last 30 years fluidised bed combustion has become well

established combustion technology

Having wide fuel flexibility and low emissions

Matured to utility scale with high efficiency (OTSC)

Well adaptable to oxyfuel with CCS (with air combustion capability)

VTT has been key research partner when taking these development

steps with world leading boiler manufacturers

Targets of development in FBC technology

Scaling up and increasing efficiency

Improving environmental performance

Widening the fuel flexibility (agro- and short rotation biomass,

challenging coal wastes)

Improving the dynamic performance (load following, minimum

load)

Towards zero CO2 with coal and negative CO2 emission with bio

Source Foster Wheeler

Source Valmet

11 23/09/2014 11

http://www.vtt.fi/img/research/ene/combustion/VTT.html


12 23/09/2014 12

Fuel characterization tests in pilot scale

Combustion

Combustion profile (heat release), fuel

reactivity

Unburned carbon (UBC)

Emissions

Main components such as CO2, O2, CO, H2O, SOx, NOx, N2O

Trace elements e.g. HCl, HF, NH3, CxHy,

Hg

Ash

Ash composition and split: bottom ash vs.

fly ash

Agglomeration, fouling and corrosion

tendency

Limestone

Reactivity compared to reference one

Estimate limestone dosage to reach the

emission limits

• optimal combustion conditions (temperature, air staging)

• furnace dimensioning

• type and location of heat transfer surfaces

• material selections

• emission control system

• ash removal systems and utilization

Data to design and optimize high

performance boiler with low emissions and high availability in terms of


http://www.vtt.fi/img/research/ene/combustion/VTT.htmlhttp://www.vtt.fi/img/research/ene/combustion/VTT.html

13 23/09/2014 13

Example results of characterization tests

14 23/09/2014 14

Slagging and deposits formation

in pilot scale CFB

Upward view to the riser after

tests with high-Ca fuel

Upward view to the

deposition probe

(simulating super heater tube)

Flue gas flow

15 23/09/2014 15

Combustion efficiency in pilot scale CFB

(100-[unburned carbon loss])

88

90

92

94

96

98

100

0 10 20 30 40 50 60 70 80 90 100

Co

mb

ust

ion

eff

icie

ncy

[%

of

LHV

]

Volatile content [w-%, dry ash free]

Blue dots from test with different fuels at temperature level 790...890ºC

Red dots from tests with ”project fuel” at varying temperature levels

16 23/09/2014 16

SO2 emissions in pilot scale CFB –

sulphur capture by inherent and added limestone

0

10

20

30

40

50

60

70

80

90

100

725 775 825 875 925

Sulp

hu

r re

ten

tio

n [

%]

Bed temperature [ºC]

With limestone

Without limestone (inherent)

17 23/09/2014 17

Nitrogen oxide emissions in pilot scale CFB –

effect of temperature and limestone

0

50

100

150

200

250

300

350

400

700 750 800 850 900 950

Emis

sio

n [

mg

/m3

n @

6%

O2

dry

]


NO (without limestone)

NO (with limestone)

N2O (without limestone)

N2O (with limestone)

18 23/09/2014 18

NO emissions in pilot scale CFB –

effect of air staging and temperature

0

50

100

150

200

250

300

780 800 820 840 860 880 900

NO

em

issio

ns [

mg/m

3n @

6 %

O2 d

ry]


Primary air share increased 50% -> 60%

Tomorrow on-line demonstration of air staging in CFB-pilot

19 23/09/2014 19

Fuel reactivity testing in bench scale BFB

15 13

46 51

111

86

258

184

0

50

100

150

200

250

300

800 900

Tim

e [s

]


High volatile fuel t50% High volatile fuel t90%

Low volatile fuel t50% Low volatile fuel t90%

Tomorrow on-line demonstration of fuel reactivity testing in bench scale BFB

20 23/09/2014 20

Limestone sulphur capture testing

in bench scale BFB

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 20 40 60 80 100 120 140 160 180

Cal

ciu

m u

tilis

atio

n [

-]

Time [min]

Limestone 1 - 780ºC Limestone 2 - 780ºC Limestone 3 - 780ºC



21 23/09/2014 21

Bed agglomeration and bed material testing

in bench scale BFB

1 Bed material feed into reactor

2 Start of fuel feeding

3' First signal of fluidisation problems

3 Defluidisation signal

4 End of fuel feeding

22 Anthracite Bituminous coal Brown coal/lignite Pet coke/Coal waste Peat Oil shale Biomass

(wood, bark etc) Agro biomass

(straw, rapeseed etc) Waste

(SRF etc) Limestone

Worldwide references of the fuels tested at VTT site

23 23/09/2014 23

Polish bituminous coal (2001)

Estonian oil shale (2001)

Hungarian brown coal (2003)

Turkish brown coal (2004)

Polish bituminous coal (2004)

Australian bituminous coal (2005)

Polish bituminous coal, oxyfuel (2006)

Rapeseed expeller (2007)

Anthracite, culm, slurry (2007)

Lignin, straw (2007)

South-African bituminous coal, Russian anthracite culm (2007)

Some VTT’s CFBC references

Direct work for customers - fuel characterisation services

Coal, coal waste, (2008)

Polish bituminous coal, wood pellets, oxyfuel (2008)

Lignin (2008)

Turkish lignite (2008)

Russian bituminous coal (2009-2010)

Brazilian sub-bituminous coal, (2010)

Spanish anthracite, petcoke (2011)

Russian anthracite (2011)

Jordanian oil shale (2012)

Coal washery rejects (2012)

Bulgarian lignite (2013)

Spanish petcoke (2013)

24 23/09/2014 24

25

Deposition of ash related material

onto heating surfaces

Agglomeration of bed

material High temperature

corrosion

Ash related problems generated from challenging fuels

Most of the problems can be avoided with a proper boiler design based on

understanding of fuel combustion behaviour

26 23/09/2014 26

Case example with lignite

27

Method for preventing chlorine

deposition on the heat-transferring

surfaces of a boiler. Aho, Martti Pat.

WO2006134227

CorroStop – water soluble sulphates

Al2(SO4)3

Fe2(SO4)3

Long-term testing done at UPM Caledonia

An example from VTT’s Lab to Market: CorroStop™

Injection

nozzles

Sulfate water

solution

Sulfate in

Sulfate

tank

Sulfate to levels

Control of flow

Sulfate pump

Injection

nozzles

Sulfate water

solution

Sulfate in

Sulfate

tank

Sulfate to levels

Control of flow

Sulfate pump

Injection

nozzles

Sulfate water

solution

Sulfate in

Sulfate

tank

Sulfate to levels

Control of flow

Sulfate pump

Before After

AEROSOLS FROM ALKALINE CHLORIDES CAN

BE BIND IN NON-HARMFUL PHASE USING ADDITIVES

28 23/09/2014 28

15 %

20 %

25 %

30 %

35 %

40 %

45 %

50 %

350 400 450 500 550 600 650 700

Steam temperature, °C

Ele

ctr

ic e

ffic

ien

cy,

%

Grate fired CHP waste incinerator

420°C, 60bar

Fluidised bed CHP plant for waste

470°C, 65bar

Ultra super critical pulverised coal fired condensing

power plant, 700°C, 330bar

Super critical coal fired condencing power plant, fluidised bed

580°C, 275bar

Grate firing for MSW

Fluidised bed for SRF

Biomass

combustion

Coal fired condencing mode

power plants

Grate fired CHP plant for biomass

500°C, 70bar

ADCOF TARGET AREA:

Fluidised bed CHP plant for biomass,

520°C, 120bar

15 %

20 %

25 %

30 %

35 %

40 %

45 %

50 %

350 400 450 500 550 600 650 700

Steam temperature, °C

Ele

ctr

ic e

ffic

ien

cy,

%

Grate fired CHP waste incinerator

420°C, 60bar

Fluidised bed CHP plant for waste

470°C, 65bar

Ultra super critical pulverised coal fired condensing

power plant, 700°C, 330bar

Super critical coal fired condencing power plant, fluidised bed

580°C, 275bar

Grate firing for MSW

Fluidised bed for SRF

Biomass

combustion

Coal fired condencing mode

power plants

Grate fired CHP plant for biomass

500°C, 70bar

ADCOF TARGET AREA:

Fluidised bed CHP plant for biomass,

520°C, 120bar

® DOUBLING THE ELECTRIC EFFICIENCY IN WASTE-TO-ENERGY :

by utilising the capability of coal ash to adsorb and chemically react with the waste-originated salts

ending to a complete absence of halogen salts in the combustion gases wherefrom

the energy can be recovered with electric efficiency of 41%.

The process has been demonstrated at VTT’s CFB unit in May 2012

In full scale demonstration target 540°C/160bar single reheat, e 40%

29 29 23/09/2014

Boiler performance analyses

Boiler performance and availability analyses at different operation conditions

Boiler-specific results on the effects of new challenging fuel blends (field testing)

Measurements and analyses for deposit formation, heat transfer and high

temperature corrosion on boiler surfaces

Tools for process feasibility, boiler economy evaluation and concept simulations

30 23/09/2014 30

Ash utilisation

Characterisation of ash and evaluation of technical

and environmental applicability for

Fertilizer use

Civil engineering applications

Concrete production

Landfilling

Evaluation of ash quality dependence on

Fuels

Combustion technology and process parameters

Additives

Development of refining methods for ashes

Productisation (End of Waste)

Techno-economical studies of whole ash chain

31 23/09/2014 31

Summary of benefits

Economy

• Fuel characterization tests can secure the investment in terms of

• high efficiency

• low emissions

• high plant availability with low costs

• Typical saving potential millions of €/year

Sustainability

• Fuel characterization tests provide facts needed in early phase of the investment

• environmental permits and public acceptance

• planning of by-products utilization(e.g. ash)

TECHNOLOGY FOR BUSINESS

pilot and bench scale fuel characterisation service for ......cfbc technology with co2 capture the...

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