Development of a pressure swing adsorption process for Carbon Dioxide capture from flue gas using solid amine sorbents.

摘要

Solid amines are comprised of adsorbent materials, like silica gel, that contain amine based organic compounds, either physically or chemically, attached within their pores. The major characteristic of these sorbents that makes them interesting for CO2 capture from flue gas is that unlike zeolites they are not negatively affected by the presence of water. The current work has been focusing on the development of a novel PSA cycle for CO2 capture from flue gas using a solid-amine sorbent composed of PEI physically immobilized on a commercial silica substrate. The goal was to achieve > 90% recovery and > 95 vol. % purity of CO2at reasonable throughputs and operating cost. A non-equilibrium kinetic model was developed to describe the reversible adsorption and desorption of CO2 on this material over a wide range of industrial relevant conditions. Effect of water on adsorption and desorption of CO2 was studied at various temperatures and pressures of CO2 using TGA. Considering the adsorption of water on this particular material and utilizing the developed model for CO2-solid amine, a series of simulations were carried out for two PSA cycles under different operating conditions for both dry and humid feeds. In this dissertation the key results regarding the use of solid amines for post combustion CO 2 capture from flue gas by PSA are presented. The effects of different parameters on the performance of the PSA process in terms of recovery and purity of CO2 and the required energy are discussed. The process conditions under which the separation goal is achievable are provided. The role of water in the PSA process performance is explored. Finally two hypothetical sorbents are proposed. The use of these sorbents can improve the performance of the PSA process in terms of water recovery in the CO2-enriched product.