Technical Assessment for Reducing CO2 Emissions
CUMMINS & BARNARD, INC
CONSULTING ENGINEERS / SINCE 1932
Assessed Value Compared to Ideal
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Assessed Value Compared to Ideal
150
Operating Cost
Operation
Weight
Size
Maintenance Protocols
Energy Consuption
CO2 Capture Efficiency
Environment Issues
Product Cost
Function and Performance
Figure 1. Evaluation of Technologies for Capturing CO2 for PC
and IGCC Power Plants.
cost
Volatility
Resistance to Corrosion
Resistance to Degradation
CO2 Capacity
CO2 Absorption Rate
Heat of Absorption
Figure 2. Evaluation of Chemical Absorbents for Capturing CO2
in a PC Power Plant.
Physical Absorption
These physical solvents were evaluated based
on 7 criteria. Selexol™ and Rectisol™ were
found to be the best physical solvents because
of their selectivity and CO2 absorption capacity.
Evaluation of Physical Absorbants
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60
40
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There are many solvents that can remove
CO2 from flue gas including: primary,
secondary, and tertiary amines, ammonia,
and formulated solvents.
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Chemical Absorption
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Chemical and Physical absorption were
found to be the best technologies, mostly
due their CO2 capturing abilities.
The best absorbent was found to be
formulated solvents, followed closely by
methyldiethanolamines (MDEA).
Michigan State University
Design Students
Faculty Advisor
Kathryn Anderson
Dr. Farhad Jaberi
Alexis Bauer
Mary Martin
Kristen Penk
80
M
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Evaluation of Available CO2 Technologies
The absorbents were evaluated and the top
solvents were recommended for chemical
absorption in a PC power plant.
Cummins & Barnard
Sponsor Representatives
Steve Herrygers
Christopher Zuelch
100
R
Provide Cummins & Barnard, Inc. with an
assessment of technologies that can be utilized
in the power industry to capture CO2 from
pulverized coal (PC) and integrated gasification
combined cycle (IGCC) power plants.
120
Assesed Value Compared to Ideal
Problem Statement
140
The industry is currently using four solvents to
capture CO2 in the gasification process:
Rectisol™, Purisol®, Selexol™, and Fluor®
solvent.
200
Ab
Physical absorption processes are temperature
and pressure dependent with absorption
occurring
at
high
pressures
and
low
temperatures.
Such processes are typically
used for CO2 separation when partial pressures
of CO2 are high, like with CO2 rejection from a
gasification process.
These technologies were evaluated on 10
criteria to determine the best CO2 capture
process for PC and IGCC power plants.
ica
l
Chemical absorption is the most widely used
method for removing CO2 and has been utilized
for the past 60 years. It is effective for low CO2
concentrations, like flue gases from coal-fired
power plants.
The six technologies determined as being
commercially
viable
were:
chemical
absorption, physical absorption, separation
membranes, low temperature distillation,
adsorption, and mineral carbonation.
he
m
Capturing CO2 post-combustion is difficult due
to the large volume of flue gases generated.
SO2 and NOx are currently sequestered, but
capturing CO2 is difficult because of the larger
process units that require more energy and
solvents.
CO2 Removal Technologies
C
Background
Evaluation of Chemical Absorbants
Cost
Non-corrosive
Solvent Stability
Solubility of Impurities
Low Vapor Pressure
Low Viscosity
High Selectivity
Figure 3. Evaluation of Physical Absorbents for Capturing CO2 in
an IGCC Power Plant.
Economics of CO2 Removal
Adding CO2 removal processes has been found
to increase capital cost as much as 77% and the
cost of electricity by at least 50%. This fact
makes optimization of methods and products
important when implementing this technology.
Conclusions
While it is expensive, using chemical and
physical solvents are the best choice to make
CO2 capture a commercially viable option.
Formulated solvents and Selexol™ should be
used to minimize cost for the PC and IGCC
processes, respectively.