The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. CO{sub 2} mass transfer rates are second order in piperazine concentration and increase with ionic strength. Modeling of stripper performance suggests that 5 m K{sup +}/2.5 m PZ will require 25 to 46% less heat than 7 m MEA. The first pilot plant campaign was completed on June 24. The CO{sub 2} penetration through the absorber with 20 feet of Flexipac{trademark} 1Y varied from 0.6 to 16% as the inlet CO{sub 2} varied from 3 to 12% CO{sub 2} and the gas rate varied from 0.5 to 3 kg/m{sup 2}-s.

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. The stripper model with Aspen Custom Modeler and careful optimization of solvent rate suggests that 7 m MEA and 5 m K+/2.5 m PZ will be practically equivalent in energy requirement and optimum solution capacity. The multipressure stripper reduces energy consumption by 15% with a maximum pressure of 5 atm. The use of vanadium as a corrosion inhibitor will carry little risk of long-term environmental or health effects liability, but the disposal of solvent with vanadium will be subject to regulation, probably as a hazardous waste. Analysis of the pilot plant data from Campaign 1 has given values of the mass transfer coefficient consistent with the rate data from the wetted wall column. With a rich end pinch, 30% MEA should provide a capacity of 1.3-1.4 mole CO{sub 2}/kg solvent.