NASA is currently using a solid amine sorbent known as HSC + for regeneratively removing CO 2 in space shuttle applications. This sorbent may also be of value for CO 2 removal in various industrial processes such as greenhouse gas control, industrial syntheses, and natural gas purification. To design novel sorbents and to design a CO 2 scrubber based on HSC + , physical and thermochemical property data are required. In this paper, we present a detailed experimental investigation of property data and long-term performance results using HSC + as a CO 2 sorbent. Differential scanning calorimetry was used to determine the heat capacity of the material. Cyclic and equilibrium capacities of the material for CO 2 pickup were determined and long-term test data show excellent performance. In addition, we have determined the heat of adsorption associated with CO 2 pickup by HSC + and the effect of moisture, using isothermal flow calorimetry. We have also performed thermal gravimetric analyses on the materials to gain insight into the stability of the material and determine the temperatures at which CO 2 and constituents of HSC + leave the surface of the material.

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Liquid amines can be immobilized within the pores of polymeric supports to provide a regenerable CO 2 sorbent. This paper describes the capture of CO 2 by a range of ethanolamines (primary, secondary, and tertiary) immobilized within the pores of high-surface-area poly(methyl methacrylate) beads. These supported amines were used to remove low concentrations (7.6 mmHg) of CO 2 by a pressure swing absorption process, where low-pressure vacuum was used to desorb the CO 2 and regenerate the sorbent. The effect on CO 2 capture of modification of primary amines to secondary amines by reaction with acrylonitrile was also evaluated. The modified amines provided nearly a factor of 2 increase in CO 2 removal capacity compared to the original primary amines. These results suggest that modified amines could potentially be used for CO 2 capture in space life support systems as well as for terrestrial flue gas CO 2 removal applications.

In this study, the absorption properties of CO 2 in seven different solid amine absorbents were measured. The specific characteristics, such as absorption capacity, absorption/desorption rate, cyclic capacity, cycle decay effect, temperature of reaction in the absorber, and optimal conditions for the CO 2 absorption process were measured. This absorption process occurred at two temperaturesseither 296.15 or 313.15 Kswhile the desorption process temperature was raised to 348.15 K. The solid amines (TEPAN and E-100AN) demonstrated higher cyclic capacity than others under these conditions. Our testing showed high reproducibility for the CO 2 capture of TEPAN and E-100AN in measuring their cyclic capacity. Diminished cyclic capacities were noted for the MEA and 194B materials, with measured drops at the third cycle of about 16.17% and 15.79% lower than those in the first cycle, respectively.