Selection of Optimal Solid Sorbents for CO2 Capture Based on Gas Phase CO2 composition

Abstract

Abstract One method to reduce anthropogenic CO2 emissions is carbon capture via the separation of CO2 from gas streams that would otherwise be released to the atmosphere. In this work, we examine the applicability, performance, and desired material properties of solid sorbent materials to capture CO2 from gas streams with varying CO2 compositions. This paper focuses on optimizing material selection and process design for given applications and determines the effect on the calculated imposed load of performing carbon capture on various gas streams. For each gas stream for CO2 separation, an optimal separation material and operational process can be identified. Previous work on this topic has been focused on sorbent and process selection for CO2 separation from coal-derived flue gas [1] , [2] . In the current work, we expand the range of possible gas streams to include a wide range of CO2 concentrations from 1-99% CO2 with the balance N2. The purpose of this is not only to identify the sorbent materials that are energetically optimal for each application, but also to determine the effect of varying CO2 concentration on overall process performance. By quantifying the effect of increased CO2 concentration or partial pressure, trade-off curves can be calculated and the effect of combustion, pre-treatment, or recycle processes that can increase CO2 partial pressure can be analyzed. Further, this can provide a trade-off analysis between using process steps, such as recycling flue gas streams, to increase CO2 concentrations before carbon capture versus capturing CO2 directly from a lower concentration gas stream. Results include the range of materials that provide near-optimal energy performance for a given application and act as a guide for material developers.