An Advanced Sorbent for Direct Air Capture

Anthropogenicemissionsofcarbondioxide(CO2)areasignificantrisktoglobalclimate .The atmospheric CO2 concentration has surpassed 400 ppm on several occasions since 2013, an increase of 100 ppm since pre-industrial revolution levels. The removal of CO2 from the atmosphere via direct air capture (DAC) is considered as an alternative to the post-combustion capture systems that can remove CO2 from the flue gases of industrial point sources. Unlike other carbon capture technologies, DAC has the advantage of not being directly linked to the existing energy infrastructure that generates the CO2, achieving mitigation irrespective of where and how emissions occur. For example, half of today’s emissions come from distributed or mobile sources (e.g. houses and cars) that are difficult to capture at the source. However, because DAC deals with low CO2 concentrations rather than concentrated streams the cost of capture is expected to be higher. TDA Research, Inc. proposes to develop adsorption-based process to directly remove CO2 from air. The new process uses a unique adsorbent that can effectively remove CO2 at ery low concentrations (i.e., 400 ppmv). A mild temperature/concentration swing will be employed to regenerate the sorbent that will enable the recovery of CO2 as a concentrated product. The sorbent will be housed in a unique gas-solid contactor that is designed to minimize the pressure drop and the associated parasitic losses (which is essential for the Direct Capture Systems). In Phase I, we will optimize the sorbent structure through molecular modeling and synthesize the new sorbent at large-scale using high throughput commercial equipment. We will use low energy densification techniques to make pellets or granules while preserving the desired adsorptive properties. We will demonstrate the stable operation of the new material through many cycles for DAC under representative conditions. We will design and optimize a cycle sequence that will achieve both high product (CO2 capture) yield and high purity. We will complete a techno-economic analysis to assess the economic merits of the new technology. CO2 is a major greenhouse gas and the major source for the anthropogenic CO2 emissions. It is the result of the combustion of fossil fuels, in particular the burning coal to generate electricity and from automotive exhaust. The proposed technology will provide a cost effective way to directly remove CO2 from the atmosphere.