Liquid, slurry and flowable powder adsorption/absorption method utilizing waste heat for on-board recovery and storage of CO
A method and system are described for on-board treatment of an exhaust stream containing CO 2 emitted by a hydrocarbon-fueled internal combustion engine (ICE) used to power a vehicle in order to reduce the amount of CO 2 discharged into the atmosphere which include: a. a treatment zone on board the vehicle containing a capture agent that is a liquid, a slurry or a finely divided flowable solid having a predetermined capacity for extracting CO 2 from the exhaust stream, the treatment zone having an inlet for admitting the exhaust gas stream and an outlet for passage of a treated exhaust stream to contact the capture agent having a reduced CO 2 content, the treatment zone including a heat exchanger with an inlet for receiving the hot exhaust gas stream from the ICE for passage in heat exchange relation with the capture agent to release CO 2 and regenerate the capture agent, and an outlet for the cooled exhaust gas stream, the treatment zone having a CO 2 discharge outlet for CO 2 released from the regenerated capture agent; b. a compression zone in fluid communication with the CO 2 discharge outlet from the treatment zone, the compression zone including one or more compressors for reducing the volume of the CO 2 ; c. a storage zone for receiving the compressed CO 2 for temporary storage on board the vehicle; d. an exhaust gas conduit in fluid communication with the treated exhaust gas stream outlet from the treatment zone; and e. at least one waste heat recovery zone for recovery of heat energy from the exhaust gas stream, the ICE cooling system and/or directly from the ICE for conversion to electrical or mechanical energy.
1. A method for reducing the amount of CO 2 discharged into the atmosphere with the exhaust gas stream emitted by an internal combustion engine (ICE) used to power a vehicle, the method comprising:
a. circulating a CO 2 capture agent between an absorption zone and a regeneration zone;
b. cooling the exhaust gas stream and contacting the cooled exhaust gas stream with the CO 2 capture agent in the absorption zone on board the vehicle, the capture agent having a predetermined capacity to extract CO 2 from the exhaust stream;
c. discharging a treated exhaust gas stream having a reduced CO 2 content into the atmosphere;
d. measuring the CO 2 level remaining in the treated exhaust gas stream and comparing the value of the measured level to a predetermined limiting value corresponding to the predetermined capacity of the CO 2 capture agent;
e. discontinuing the contact of the exhaust gas stream with the capture agent when the concentration of the CO 2 extracted by the capture agent has reached the predetermined limiting value of (c);
f. heating the CO 2 capture agent to release the extracted CO 2 and regenerate the capture agent;
g. recovering an essentially pure CO 2 gas stream;
h. compressing the recovered CO 2 gas on board the vehicle to reduce its volume; and
i. temporarily storing the compressed CO 2 on board the vehicle.
2. A method for reducing the amount of CO 2 discharged into the atmosphere with the exhaust gas stream emitted by an internal combustion engine (ICE) used to power a vehicle, the method comprising:
a. circulating a CO 2 capture agent between an absorption zone and a regeneration zone;
b. cooling the exhaust gas stream and contacting the cooled exhaust gas stream with the CO 2 capture agent in the absorption zone on board the vehicle, the capture agent having a predetermined capacity to extract CO 2 from the exhaust stream;
c. discharging a treated exhaust gas stream having a reduced CO 2 content into the atmosphere;
d. discontinuing the contact of the exhaust gas stream with the capture agent when the concentration of the CO 2 extracted by the capture agent has reached a predetermined level;
e. heating the CO 2 capture agent to release the extracted CO 2 and regenerate the capture agent, wherein the CO 2 capture agent is heated by heat exchange with the hot exhaust gas stream or hot engine coolant, wherein the heat exchange occurs while the capture agent is moving;
f. recovering an essentially pure CO 2 gas stream;
g. compressing the recovered CO 2 gas on board the vehicle to reduce its volume; and
h. temporarily storing the compressed CO 2 on board the vehicle.
3. A method for reducing the amount of CO 2 discharged into the atmosphere with the exhaust gas stream emitted by an internal combustion engine (ICE) used to power a vehicle, the method comprising:
a. circulating a CO 2 capture agent between an absorption zone and a regeneration zone;
b. cooling the exhaust gas stream and contacting the cooled exhaust gas stream with the CO 2 capture agent in the absorption zone on board the vehicle, the capture agent having a predetermined capacity to extract CO 2 from the exhaust stream, wherein the CO 2 capture agent is selected from the group consisting of
a liquid absorbent,
a high boiling temperature ionic liquid,
a high boiling temperature heat transfer fluid,
a solution of an alkali metal carbonate in a high boiling temperature liquid,
an ionic liquid carbonate,
a high boiling temperature colloidal solution of small particles,
a high boiling temperature liquid with suspended solid particles,
a high boiling temperature solvent that stabilizes a carbamate of a conventional amine solute, and
a finely divided flowable solid absorbent that is contacted with the exhaust gas stream in counter-current flow relation;
c. discharging a treated exhaust gas stream having a reduced CO 2 content into the atmosphere;
d. discontinuing the contact of the exhaust gas stream with the capture agent when the concentration of the CO 2 extracted by the capture agent has reached a predetermined level;
e. heating the CO 2 capture agent to release the extracted CO 2 and regenerate the capture agent;
f. recovering an essentially pure CO 2 gas stream;
g. compressing the recovered CO 2 gas on board the vehicle to reduce its volume; and
h. temporarily storing the compressed CO 2 on board the vehicle.
4. A method for reducing the amount of CO 2 discharged into the atmosphere with the exhaust gas stream emitted by an internal combustion engine (ICE) used to power a vehicle, the method comprising:
a. circulating a CO 2 capture agent between an absorption zone and a regeneration zone;
b. cooling the exhaust gas stream and contacting the cooled exhaust gas stream with the CO 2 capture agent in the absorption zone on board the vehicle, the capture agent having a predetermined capacity to extract CO 2 from the exhaust stream;
c. measuring the CO 2 content of the exhaust stream downstream of the capture agent;
d. discharging a treated exhaust gas stream having a reduced CO 2 content into the atmosphere,
e. discontinuing the contact of the exhaust gas stream with the capture agent when the concentration of the CO 2 extracted by the capture agent has reached a predetermined level;
f. heating the CO 2 capture agent to release the extracted CO 2 and regenerate the capture agent;
g. recovering an essentially pure CO 2 gas stream;
h. compressing the recovered CO 2 gas on board the vehicle to reduce its volume; and
i. temporarily storing the compressed CO 2 on board the vehicle.
5. The method of claim 4 , in which the CO 2 content of the exhaust gas stream is reduced by at least 5%.