CO2 Recovery Plants : Process Flow
Flow of the Standard Process
The flue gas blower feeds flue gas from the plant stack to the KM CDR Process®. After cooling in the flue gas cooler to a temperature of 45 degrees centigrade or lower, the flue gas is fed into the bottom section of the absorber and upward through the packing material inside the tower. As the flue gas passes through the material, the KS-1™ solvent is distributed evenly from the top of the absorber onto the packing material, allowing the solvent to selectively capture the CO2 from the gas. Next, the KS-1™ solvent with the captured CO2, "CO2-rich solution", is collected in the bottom section of the absorber, heat exchanged, and pumped into the stripper from the upper section. Once within the stripper, the CO2-rich solution is distributed onto a strip of internal packing placed in contact with an upward stream of stripping-steam produced by the reboiler. This steam strips the CO2 from the CO2-rich solution at the stripper, yielding CO2 with a high purity of 99.9 vol. percent or more at 1.6 barA (Dry Base). At the final stage, the stripped lean solution is cooled down and reintroduced into the absorber through the heat exchanger and cooler.
Unique concept to utilize lean solvent and steam condensate heat for regeneration inside the stripper.
Performance & Improvement
- Steam Consumption
1.30 Tons Steam/Ton CO2
(660 Kcal/Kg. CO2: Expected)
Note: Steam = 3 Bar G. Saturated
- Regeneration Energy less than 700 Kcal/Kg.
CO2 can be guaranteed.
The "Improved KM CDR Process" consumes 15 percent less than the conventional KM CDR Process».
Application for Recovered CO2
EOR (Enhanced Oil Recovery)
CO2 is a highly effective media for enhanced oil recovery. When injected and mixed into crude oil, CO2 and crude oil form a miscible condition thus enhancing its flow ability in the oil layer. Increased flow ability improves the productivity and recovery ratio of crude oil. The use of CO2 EOR with the CO2 recovered from the flue gas of industrial plants is an efficient way to prevent global warming and reinforce energy security at the same time. The figure below indicates a typical industrial scale CO2 EOR operation.
CO2 Geological Sequestration
Geological sequestration projects are being carried out in several countries. The recovered CO2 from flue gas is stored in deep saline aquifers about 1000 meters below the surface of the ground. Various large scale coal fired flue gas CO2 capture and sequestration projects are being developed and will on-stream around 2012-2015.
Chemical Use - UREA Production
- Maximize Urea Production
- Minimum Reconstruction
- Reduced CO2 Emissions
Chemical Use - Methanol Production
The carbon/hydrogen ratio is adjusted for optimum methanol synthesis by introducing CO2 into the process from the reformer or boiler flue gas, thereby increasing the production of methanol. This process has five important merits:
- Increased Methanol Production
- Minimum Reconstruction
- No Reformer Reconstruction
- A Reduced Rate of Natural Gas Consumption
- Reduced CO2 Emission
Dry Ice, Welding, Etc.
Conceptual "Large-Scale Plant" Design Study
MHI has developed large-scale CO2 recovery plants based on its proven experience and technologies. MHI has recently completed a basic design package for a 3,000 metric T/D (ton per day) -single train. The package is now ready for delivery on demand under full commercial arrangements.