Fourth Annual Conference on Carbon Capture & Sequestration · Fourth Annual Conference on Carbon...

transcript

Fourth Annual Conference on Carbon Capture & Sequestration

Developing Potential Paths Forward Based on the Knowledge, Science and Experience to Date

Capture and Separation- Oxyfuel Combustion

CO2 Compression Units for Oxy-Fuel CombustionKourosh E. Zanganeh, Ahmed Shafeen, Carlos Salvador, Murlidhar Gupta, and Bill

Pearson

Fossil Fuels and Climate Change Group,CANMET Energy Technology Center, Natural Resources Canada, 1 Hannel Drive, Ottawa, ON, K1A 1M1, Canada

May 2-5, 2005, Hilton Alexandria Mark Center, Alexandria Virginia

Outline

• Fuel combustion and CO2 capture pathways• Oxy-fuel Combustion• CO2 compression and capture processes

– Once-through process– Autorefrigeration (Fluor process)– Novel CETC process

• Pretreatment and moisture separation• Process modeling and simulation• Results• Conclusions

Capture Pathways

Air-combustion

Biomass

Petcoke

Gasification

Oxy-combustion

CO2 Capture

Power & Heat

CO2 (>90 bar) Transport for

Storage

CO2 Capture

Combustion Power & Heat

Power & Heat

CO2 Capture & Compression

Flue gas

5-15% CO2

@ 1 bar

Syngas

20-40% CO2

Flue gas

>80% CO2

@ 1 bar

CO2 (~20 to 50 bar)

CO2 Compression

> 99%@ 1bar

Schematic of Oxy-Fuel Combustion for Power or Heat Generation

Recycled Flue Gas

Air SeparationUnit

Gas Purification

Fossil fuelcombustion

Power or Heat

StorageCO2

Compression

1/5 exit gas volume relative to airCO2 at 80-98% by volume

Other pollutants and/or water

For process heaters, furnaces and boilers

An Idealized Thermodynamic Path of Compression, Cooling, and Pipeline Operations

for CO2

Mohitpour M., Golshan H., and Murray A., Pipeline Design and Construction: A Practical Approach, New York, American Society of Mechanical Engineers Press, 2000

CO2 Phase Diagram

http://www.acpco2.com/index.php?lg=en&pg=2121

Conventional Multistage Compression

Autorefrigeration Separation of Carbon Dioxide (Fluor Process)

PretreatmentModule

Vent Module

PumpingModule

Expander &Separator

Module

2nd StageCompression

Module

1st StageCompression

Module

ToAtmosphere

(Stack Flue Gas)

CO2 Product Stream

Stream 1 Stream 5

Stream 8

Stream 3

Stream 4

Stream 7

Stream 6Stream 2Feedgas

(Extract Energy)

(H2O) (H2O)

Novel CETC Process

• Proprietary process• Some process simulation results will

be presented• Comparison between the results:

– CETC Compression process versus Fluor Autorefrigeration/separation process

Assumptions for Simulation

• Same baseline design conditions • Inlet pressure and temperature

– 1 bar, 40 0C• Vent pressure and temperature

– 6 bar; above dew point• Product pressure and temperature

– Optimum pressure is derived from the simulation at -5 0C

Feed Gas Composition

Properties Unit Compressor InletFeed gas-1 Feed gas-2 Feed gas-3

Temperature 0C 40 40 40Pressure bar 1 1 1Flow Rate kg/hr 181.0 181.0 181.0Composition

CO2 - 0.7443 0.800 0.8467H2O - 0.0667 0.070 0.0667O2 - 0.0335 0.030 0.0304N2 - 0.1355 0.0845 0.0519SO2 - 0.0012 0.005 0.0014Ar - 0.0183 0.010 0.0024NO - 0.0005 0.0005 0.0005NO2 - 0.0001 0.0001 0.0001

Mole Fraction Mole Fraction Mole Fraction

Pretreatment and Moisture Separation• The extent of pretreatment depends on:

– Design considerations( ice formation, corrosion, metal properties, etc.)

– Cost (cleaning cost, additional energy penalty, material cost, etc.)

– Application (EOR, Storage, ECBM, etc)

Feed Gas Inlet Temperature to 1st StageTemp Vs Moisture remained in Line

-35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40

Inlet Temp ( 0C)

% Moisture remaining with increased Cooling

00.10.20.30.40.50.60.70.80.9

0 1 2 3 4 5 6 7

Cooling Energy Demand (kW)

-25-20-15-10-50510152025303540

Moisture remain/Initial Moisture Cooling Temperature

Process Modeling and Simulation

• Process Modeling– Both processes were modeled in HYSYS– Same initial feed gas characteristics and final product

conditions.– Product CO2 purity equal or above 95%

• Processes Optimization– CO2 recovery– Energy requirement– Stage pressure and recycle ratio

Comparison of Results

Fluor Process CETC Process

Feed Gas 1 Feed Gas 2 Feed Gas 3

CO 2 r

Fluor Process at Different Optimized 2nd

Stage Pressure

Optimized Fluor Process Optimized CETC Process Fluor w /CETC pressure

CO 2 r

Impurities Distribution in Vent Stream

F luo r Process C ET C Process

F eed Gas 1 F eed Gas 2 F eed Gas 3

F luor Process CETC Process

F lu o r Pro ce ss C ET C Pro ce ss

F eed G as 1 F eed G as 2 F eed G as 3

F luor Process CET C Process

Impurities Distribution in Product Stream

F luor Process CET C Process

F lu o r Pro ce ss C ET C Pro ce ss

F lu o r P ro ce ss C E T C P ro ce ss

F lu o r P ro c e s s C E T C P ro c e s s

Conclusions• Many factors impact the design of a CO2 compression

unit for oxy-fuel combustion• The impact of impurities in the process design is an

open area for research• The once-through CO2 compression process is well

established and easy to implement.• Autorefrigeration process performance is superior to

the once-through compression process• Process simulation results shows that CETC process

offers significant improvement over Autorefrigerationprocess. – Improved energy efficiency at product purity above 95% – Lower liquid product pressure before the pumping module– Higher recovery rates

Fourth Annual Conference on Carbon Capture & Sequestration · Fourth Annual Conference on Carbon...

Documents