Conference Dates

May 22-27, 2016


Temperature swing adsorption processes have been proposed as an alternative to common amine scrubbing processes for CO2 capture from stack flue-gas streams, as they have the potential to reduce the overall capture costs significantly. In the recent years, researchers have put a great effort into the development of highly selective CO2 adsorbent materials with sufficiently large CO2 transport capacities and cyclic operating stability. However, comparably little work has been attributed to the development of suitable reactor designs or to the experimental study of continuously operated temperature swing adsorption (TSA) processes that utilizes those adsorbent materials.

The authors of this work most recently introduced a reactor system that allows for effective and efficient operation of the TSA process. The system comprises two interconnected multi-stage fluidized bed columns that enable counter-current contact of adsorbent and gas streams in both columns whilst allowing for effective heat management through indirect heat exchange in each stage. Based on the proposed reactor design, a fully integrated bench scale unit (BSU) has been constructed and put into operation to deliver a proof of concept and to further study the process experimentally (see Figure 6). Each of the BSU columns comprises five fluidized bed stages that are operated in the bubbling bed regime. Transport of solids between the two columns is carried out in two transport loops consisting of a screw conveyor, a riser and a gravitational gas/solids separator each. An amine-functionalized solid sorbent selectively adsorbs CO2 in the adsorber at low temperature and is subsequently regenerated in the desorber column at higher operating temperature, before it is returned to the adsorber. This work presents results obtained from the first continuous CO2 capture experiment within the unit.

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