evaluation of post-combustion carbon capture processes
TRANSCRIPT
Evaluation of Post-Combustion Carbon Capture Processes
Dr. Satish Reddy
Post Combustion CO2 Capture
P t C b ti C t i th l f CO f l Post Combustion Capture is the removal of CO2 from low-pressure
flue gases
Reasons for post combustion CO2 capture:
E i t l R l t– Environmental or Regulatory
– CO2 for EOR or industrial use
Examples of Post Combustion Capture ProcessesProcesses
Ammonia/Chilled ammonia processes:– Powerspan– Alstom
A i b d Amine based processes:– Aker Kvaerner– Cansolv– Fluor– Mitsubishi Heavy Industries
Siemens– Siemens
Typical Amine ProcessPRODUCT CO2
ABSORBER VENT
CW
DEMIN WATER MAKEUP
CW
CWCW
LPSTEAM LP
STEAM
CW
FLUE GASFEED
EXCESSWATER
WASTE TODISPOSAL
MAKEUPSOLVENT
SODA ASH
Fluor’s Background in CO2 capture
Fluor has been involved in CO2 capture since the early 1990s.
Built/licensed over 26 plants worldwide Built/licensed over 26 plants worldwide.
Executed numerous types of projects on gas, fuel oil and coal
fluegas
Fluor has worked on several projects and has a good knowledge of Fluor has worked on several projects and has a good knowledge of
the variables that affect process performance.
Benchmark for New Processes
New processes often report their performance as compared to monoethanolamine (MEA) because it was the first solvent used in the marketplacethe marketplace.
However when reporting the performance data, there are several unknowns about the reference MEA process comparison:unknowns about the reference MEA process comparison:
– Solvent strength and capacity
Type of flue gas– Type of flue gas
– Coolant type and temperature
Not knowing the exact basis of the MEA benchmark, comparisons are often flawed.
The Effect of Varying Parameters
The following slides present the effect of varying the following SMparameters on the performance of Fluor’s Econamine FG PlusSM
(EFG+) process:– Type of flue gas (coal-fired boiler, gas turbine, hydrogen plant
reformer)– Coolant Temperature– Site ElevationSite Elevation– Flue Gas Temperature– Air cooling vs. Water cooling
S C– Solvent Concentration
Each parameter will be varied while keeping other variables constantconstant.
Reboiler Duty is the process heat required (usually supplied by low pressure steam).
Types of Flue Gas
Hi h t ti f CO i th fl ill t i ll i Higher concentrations of CO2 in the flue gas will typically require a lower reboiler duty.
CO
Type of Gas
CO2Concentration
(mol %)Normalized
Reboiler DutyGas Turbine (with Fluegas Recirculation) 4.6 1.00
Coal-fired Boiler 9.0 0.97
H2 Plant Reformer with PSA 18.3 0.95with PSA
Types of Flue Gas
Hi h t ti f CO i th fl ill t i ll Higher concentrations of CO2 in the flue gas will typically require a lower power consumption.
Type of GasCO2 Concentration
(mol %)Normalized Power
ConsumptionType of Gas (mol %) ConsumptionGas Turbine (with Fluegas Recirculation) 4.6 1.00
Coal-fired Boiler 9.0 0.71
H2 Plant Reformer with PSA 18.3 0.58PSA
Coolant Temperatures –Effect on Reboiler DutyEffect on Reboiler Duty
Reboiler duty for various coolant temperatures
Site Elevation –Effect on Reboiler DutyEffect on Reboiler Duty
Reboiler duty for various site elevations
Coolant Type
Water cooling will allow for deeper process cooling than air cooling.
Water cooling will have a lower power consumption and reboiler duty g p p y
than air cooling.
Hybrid cooling: Bulk air cooling followed by trim water cooling Hybrid cooling: Bulk air cooling followed by trim water cooling.
– This is typically done at locations where the availability of cooling
i li i dwater is limited.
Coolant Type –Effect on Reboiler DutyEffect on Reboiler Duty
1
uty
0.99
boile
r Du
0 98zed
Reb Air Cooling
Water Cooling0.98
Nor
mal
iz
0.97
N
Coolant Type
Coolant Type –Effect on Power ConsumptionEffect on Power Consumption
1
0 8
0.9
Pow
er
ptio
n
0.7
0.8
mal
ized
on
sum
p Air CoolingHybrid CoolingWater Cooling
0.6Nor
m Co Water Cooling
0.5Coolant Type
Solvent Concentration –Effect on Reboiler DutyEffect on Reboiler Duty
1
uty
0 8
0.9
boile
r Du
0.7
0.8
zed
Reb Generic (20 wt%)
EFG+
0.6
Nor
mal
iz
0.5
N
Solvent Concentration
Solvent Concentration –Effect on Power ConsumptionEffect on Power Consumption
1
0 8
0.9
Pow
er
tion
0.7
0.8
mal
ized
on
sum
p
Generic (20 wt%)EFG+
0.6Nor
m Co
0.5Solvent Concentration
Performance Assessment Basis
A i th i lid i b t As seen in the previous slides, a comparison between technologies could be significantly off if the basis for each is differenteach is different.
Based on the parameters selected, reboiler duties and power consumption estimates could be off by 30 to 50%!power consumption estimates could be off by 30 to 50%!
Performance Assessment Basis
In order to evaluate different technologies, all parameters should be
compared on a standardized basis.compared on a standardized basis.
Similar to ISO rating conditions for gas turbines, a standard needs to
be developed for post combustion CO2 capture technologies.
Performance Assessment Basis:Gas TurbineGas Turbine
Gas Turbine Exhaust Example:
– 3.5 mol% CO2
– 15 mol% Oxygen
– < 1 ppmv SO22
– A water cooled plant with cooling water supplied at 30°C.
– Site elevation = Sea levelSite elevation Sea level
– Flue Gas Temperature and Pressure = 65°C and 1 bar a.
CO 90%– CO2 recovery = 90%
Performance Assessment Basis:Coal-fired BoilerCoal fired Boiler
Coal-fired Boiler Exhaust Example: Coal-fired Boiler Exhaust Example:– 12 mol% CO2– 4 mol% Oxygen
200 SO– 200 ppmv SO2– A water cooled plant with cooling water supplied at 30°C.– Site elevation = Sea level– Flue Gas Temperature and Pressure = 50°C and 1 bar a.– CO2 recovery = 90%
Performance of technologies should then be quoted based on these standards.
Normalization of Other Parameters to make a Technology SelectionTechnology Selection
Th CO d t d lit t b l The CO2 product pressure and quality must be equal.– The product pressure is approximately the regeneration
pressurepressure.– Chilled ammonia has a higher regeneration pressure than
amines.– Therefore, other processes need to include the extra power
required to achieve the same pressure as an ammonia process.p
Normalization of Other Parameters to make a Technology SelectionTechnology Selection
The minimum temperature approaches on the heat exchangers must be optimized (equal if appropriate).
If steam consumption is given as a flowrate, the steam pressure and temperature must be identified.
Reboiler condensate return temperature must be identified.
Emissions should be in compliance with federal and/or local Emissions should be in compliance with federal and/or local standards.
Normalization of Other Parameters to make a Technology SelectionTechnology Selection
If a process requires additional capital
or utilities (e g to normalize productor utilities (e.g. to normalize product
pressure or for emissions control) to
put the comparison on the same
basis the CAPEX and OPEX need tobasis, the CAPEX and OPEX need to
be accordingly adjusted.
Parameters required to make a Technology SelectionSelection
O ti th t t ll b Operating expenses – these parameters must all be included in the operating cost:– Steam consumptionSteam consumption– Electric power consumption– Solvent/other chemicals consumption– Operating and Maintenance costs
Capital cost
Plot space requirements
Commercial Experience Commercial Experience
Technology Verification
Parameters required to make a Technology SelectionSelection
Environmental Signature – clients are becoming extremely sensitive to the environmental impact of CO2 capture processes.
– Emissions to Air
– Solid/Liquid Waste
– Material Safety Data Sheets for all chemicals in the process
– Health, Safety, Environmental (HSE) Standards for the location
Costs of CO2 capture
By amortizing the capital cost over the life of a project and adding the
annual operating cost, a cost per ton captured/avoided can be
calculated.
In addition to the calculated costs commercial experience In addition to the calculated costs, commercial experience,
environmental signature, plot space required, and technology
verification should be completed to make a proper technologyverification should be completed to make a proper technology
selection.
Conclusions
There is a considerable technology development activity in the CCS
field.
Inflated or inaccurate claims of process performance can create
f i d l d t th h i f t h lconfusion and lead to the wrong choice of technology.
Standards for quoting performance need to be urgently established.
Questions
Thank you for listening!
28
Questions?
C t t Contacts:
http://www.fluor.com/econamine
Satish Reddy
(+1) 949 349 4959(+1) 949 349 4959