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 best K{sup +}/PZ solvent, 4.5 m K{sup +}/4.5 m PZ, requires equivalent work of 31.8 kJ/mole CO{sub 2} when used with a double matrix stripper and an intercooled absorber. The oxidative degradation of piperazine or organic acids is reduced significantly by inhibitor A, but the production of ethylenediamine is unaffected. The oxidative degradation of piperazine in 7 m MEA/2 m PZ is catalyzed by Cu{sup ++}. The thermal degradation of …
continued below
Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.
Descriptive information to help identify this report.
Follow the links below to find similar items on the Digital Library.
Description
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 best K{sup +}/PZ solvent, 4.5 m K{sup +}/4.5 m PZ, requires equivalent work of 31.8 kJ/mole CO{sub 2} when used with a double matrix stripper and an intercooled absorber. The oxidative degradation of piperazine or organic acids is reduced significantly by inhibitor A, but the production of ethylenediamine is unaffected. The oxidative degradation of piperazine in 7 m MEA/2 m PZ is catalyzed by Cu{sup ++}. The thermal degradation of MEA becomes significant at 120 C. The solubility of potassium sulfate in MEA/PZ solvents is increased at greater CO{sub 2} loading. The best solvent and process configuration, matrix with MDEA/PZ, offers 22% and 15% energy savings over the baseline and improved baseline, respectively, with stripping and compression to 10 MPa. The energy requirement for stripping and compression to 10 MPa is about 20% of the power output from a 500 MW power plant with 90% CO{sub 2} removal. The stripper rate model shows that a ''short and fat'' stripper requires 7 to 15% less equivalent work than a ''tall and skinny'' one. The stripper model was validated with data obtained from pilot plant experiments at the University of Texas with 5m K{sup +}/2.5m PZ and 6.4m K{sup +}/1.6m PZ under normal pressure and vacuum conditions using Flexipac AQ Style 20 structured packing. Experiments with oxidative degradation at low gas rates confirm the effects of Cu{sup +2} catalysis; in MEA/PZ solutions more formate and acetate is produced in the presence of Cu{sup +2}. At 150 C, the half life of 30% MEA with 0.4 moles CO{sub 2}/mole amine is about 2 weeks. At 100 C, less than 3% degradation occurred in two weeks. The solubility of potassium sulfate in MEA solution increases significantly with CO{sub 2} loading and decreases with MEA concentration. The base case corrosion rate in 5 M MEA/1.2M PZ is 22 mpy. With 1 wt% heat stable salt, the corrosion rate increases by 50% to 160% in the order: thiosulfate< oxalate<acetate<formate. Cupric carbonate is ineffective in the absence of oxygen, but 50 to 250 ppm reduces corrosion to less than 2 mpy in the presence of oxygen.
This report is part of the following collection of related materials.
Office of Scientific & Technical Information Technical Reports
Reports, articles and other documents harvested from the Office of Scientific and Technical Information.
Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.
Rochelle, Gary T.; Sexton, Andrew; Davis, Jason; Hilliard, Marcus; Xu, Qing; Wagener, David Van et al.CO2 Capture by Absorption with Potassium Carbonate,
report,
March 31, 2007;
Austin, Texas.
(https://digital.library.unt.edu/ark:/67531/metadc879158/:
accessed April 25, 2024),
University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu;
crediting UNT Libraries Government Documents Department.
