dynamic simulation study on igcc process with novel activated carbon ... 8b and 9b/9b1 yu… ·...

Dynamic Simulation Study on IGCC Process with Novel

Activated Carbon based Pre-combustion Carbon Capture

10th ECCRIA Conference (UoH)

Authors: Y. Wang1, S. Caldwell2, *J. Wang1, J. Wood2, S. Guo1

1School of Engineering, University of Warwick, UK

2School of Chemical Engineering, University of Birmingham, UK

17th Sep 2014

Power and Control Systems Research Laboratory

School of Engineering

University of Warwick

Content • Overview of the project

• Project introduction

- ASU unit

- Gasifier module: raw syngas

- WGS module: shifted syngas

- Combined cycle and power generation

- Energy analysis of IGCC with/without CC unit

• Summary

Overview of the project

• General acceptance that CO2 emissions are affecting the

climate

• UK emissions targets for power stations is a reduction from

500 to 50 gCO2/kWhr by 2030 (1)

• Up to 18 GW of investment of CCS power stations is

possible in the 2020s

• By 2030, 26% of global emissions from China, with 98% of

power generation emissions from coal (2)

• $2.7 trillion investment in power by 2030 (3)

• 50/50 split favouring pre-combustion to post-combustion

capture (3) 1. Turner, A. et al. The Fourth Carbon Budget - Reducing emissions through the 2020s. London :

Committee on Climate Change, 2010.

2. Grubb, M. Generating Electricity in a Carbon Constrained World. London : Elsevier, 2010.

3. Liang, X et al. 2011, Applied Energy, Vol. 88, pp. 1873-1885

Overview of the project • Collaboration between Nottingham, Birmingham, Warwick, UCL,

Institute of Coal Chemistry (Chinese Academy of Sciences) and

Tsinghua University (China)

• Project looks to investigate the next generation of Activated Carbon

adsorbents for CO2 capture in IGCC processes

• Project Split into 2 tasks

– Active Carbon preparation, characterisation, testing and modelling

– Modelling the impact of CO2 capture on the operation of IGCC

processes

• The role of Warwick:

– To develop a complete process of IGCC power plant model integrated

with pre-combustion carbon capture process.

– To conduct simulation study and analysis of dynamic responses of the

whole plant.

Overview of the project

Key modules for IGCC process:

a.GEM with auxiliary systems：Coal feed, ASU, Gasifier, WGS;

b.Combined cycle system: Gas turbine, Heat recovery boiler, steam turbine.

Figure1. Simplified ‘capture ready’ IGCC power plant procedure



- ASU unit




- Energy analysis of IGCC without CC unit

• Summary

Project introduction- ASU

Figure1. Simplified ‘capture-ready’ IGCC power plant procedure

Stream Air O2 HP N2 MP N2

LP N2

F 1 0.21 0.066 0.262 0.459

X N2 0.781 0.017 1 0.991 0.982

X O2 0.21 0.95 0 0.002 0.004

X Ar 0.009 0.033 0 0.007 0.014

P bar 5.07 48 88 25 1.15

T 293 295 295 500 295

Air separation unit (distillation process)

Coal type Illinois 6 Australia Fluid Coke

Specific energy

consumption KJ/mol air 4.76 4.76 4.76

Total energy

consumption MW 17.7 17.9 21.2

Feed pre-processing

MW 8.3 8.4 10.0

MHX MW 3.0 3.0 3.5

Distillation MW 4.7 4.7 5.6

Post processing MW 1.7 1.8 2.1

Table 1: Break-down of the total energy destruction over the different process parts of the

two-column ASU design.



- ASU unit





• Summary

Project introduction- Gasifier

Figure1. Simplified ‘capture-ready’ IGCC power plant procedure

Project introduction- Gasifier

Gasifier module

Gasifier model input Comparison of simulation

result and reference data

Used for the raw syngas

input to the following

modules

Gasifier module steady state analysis

Figure6.Syngas content change with coal slurry

concentration unit(kg/kg)

Figure7. Syngas content change with coal slurry concentration

unit (kg/kg)

Figure8. Syngas content change with oxygen/coal

ratio unit(kg/kg)

Figure 9. Syngas content change with oxygen/coal

ratio(kg/kg)

Three different type of coal are applied to the simulation to test the process

dynamic response. The syngas flow rises from 0.1 to 100mol/s within 100

seconds and it will first enter the WGS module for shift reaction.

Gasifier module generate raw syngas

Figure 10. Analysis of Texaco gasifier (quench)

Ilinois6 Australia Fluid Coke

Coal input (t/h) 100 100 100

Dry feed stock thermal energy input -

LHV(MW) 817.89 770.64 824,77

Oxygen input (t/h) 86 87 103

Syngas generation (kmol/s) 3.1 3.1 3.2

Carbon conversion rate(%) 98 98 98

Cold gas efficiency (%) 71.5 70.0 74.2

Raw syngas H2 mol% 30.1 29.6 23.7

Raw syngas CO mol% 41 35.4 47.2


• Progress introduction

- ASU unit





• Summary

Project introduction- GEM

Raw syngas contains H2, CO, CO2, CH4, H2O, N2,O2

WGS reaction:

Built with Simulink-based toolbox- Thermolib:

Calculation of syngas content

change and heat recovery

Water gas shift reactor module

Figure 11. Shifted syngas CO2

concentration dynamic change

Figure 12. Shifted syngas H2

concentration dynamic change

Water gas shift reactor module

Figure 13. Shifted syngas temperature dynamic change



- ASU unit





• Summary

• Future work

Gas turbine module Brayton cycle

Gas turbine with HRSG

Project introduction- Combined Cycle

Fig5 . Gas turbine power

output dynamic change

Combined cycle module

Figure 14. Gas turbine power output dynamic change

Combined cycle module

Figure 15. Combined cycle power output dynamic change



- ASU unit





• Summary

Energy analysis of IGCC without CC unit Ilinois6 Australia Fluid Coke

Gross electricity efficiency (%) 45.2 45.3 45.2

Net power efficiency (%) 41.7 43.8 43.6

Coal input (t/h) 100 100 100

Dry feed stock thermal energy input -

LHV(MW) 817.89 770.64 824,77

Oxygen input (t/h) 86 87 103

Syngas generation (kmol/s) 3.1 3.1 3.2

Cold gas efficiency (%) 71.5 70.0 74.2

Carbon conversion rate(%) 98 98 98

Gas turbine output (MW) 238.2 220.2 236.4

Steam turbine output (MW) 158.8 146.8 157.6

Combined cycle output (MW) 370 367 394

ASU power consumption+O2

compression (MW)

19.35 19.575 23.175

Total ancillary power

consumption

28.88 29.22 34.59

Energy analysis of IGCC with CC unit

Power consumption:

Pressurization; H2 loss along with CO2 capture;

Fig 16. Experiment bed in UoB

Reference: Calin-Cristian Cormos, Integrated assessment of IGCC power generation technology with carbon capture and storage (CCS), Energy, Volume

42, Issue 1, June 2012, Pages 434-445, ISSN 0360-5442, http://dx.doi.org/10.1016/j.energy.2012.03.025.

(http://www.sciencedirect.com/science/article/pii/S0360544212002162) Keywords: Power generation; IGCC; CCS (Carbon capture and storage); Techno-

economic and environmental evaluations

1. Pressurization;

2. Adsorption;

3. Depressurization

& pressurization;

4. Blow down;

5. Purge(rinse)

Energy analysis of IGCC without CC unit

Heavy product: CO2 stream

Light product: sweet syngas


Shifted syngas H2 mol% 57.6 56.8 53.2

Shifted syngas CO2 mol% 41.1 42.0 45.3

Sweet syngas CO2 mol% 3.27 3.35 3.61

Sweet syngas H2 mol% 50.2 49.51 46.34

Gross efficiency loss%

(92% CO2 captured) 12.8 12.8 12.8

Reference efficiency loss%

(93% CO2 captured post-combustion) 8.78 8.78 8.78

92% CO2 captured

Energy analysis of IGCC without CC unit

Heavy product: CO2 stream

Light product: sweet syngas


Shifted syngas H2 mol% 57.6 56.8 53.2

Shifted syngas CO2 mol% 41.1 42.0 45.3

Sweet syngas CO2 mol% 3.27 3.35 3.61

Sweet syngas H2 mol% 50.2 49.51 46.34

Gross efficiency loss%

(80% captured) 6.5 6.5 6.5

Reference efficiency loss%(93.98%

captured post-combustion) 8.78 8.78 8.78

80% CO2 captured


• Progress review

- ASU unit





• Summary

Summary • For air separation unit, the pre-processing of air accounts for 47% of total

energy consumption while the distillation process takes 26.5%, the transport

of liquefied oxygen and nitrogen will cause further loss;

• Rise of coal slurry concentration will improve the syngas quality while the

oxygen input need to controlled carefully;

• The integration of individual ASU and IGCC is important for energy saving

and efficiency improvement;

• The main reason of energy loss cased by CO2 capture is the H2 loss, in terms

of carbon capture rate higher than 90%, PSA consume relative more energy

than post-combustion capture process;

• Shifted syngas can be used to heat the steam of HRSG, and cooled shifted

syngas will be ready for carbon capture process;

• Model in Matlab and Simulink environment can successfully reflect the whole

picture of IGCC dynamic system;

THANKS FOR

YOUR ATTENTION!

dynamic simulation study on igcc process with novel activated carbon ... 8b and 9b/9b1 yu… ·...

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