Wood-structured carbon with reassembled pores showing high propylene adsorption rate for efficient separation of propylene/propane
Abstract
Efficient separation of propylene/propane requires enhancing adsorption rates on adsorbents, while maintaining high adsorption capacity and selectivity, heavily relying on engineering pore structures within the adsorbents. Herein, we have prepared wood-structured carbon with reassembled pores by using wood frameworks incorporated with CuCl2 and a polymer coating. Upon carbonization, the wood framework transforms into microporous carbon, while the polymer coating converts into molecular sieving carbon. Notably, the evaporation of CuCl produced from the in-situ reduction of CuCl2 creates additional micropores in the molecular sieving carbon layer. This wood-structured carbon adsorbent exhibits a propylene diffusion constant of 0.011 min-1 at 0.5 bar, which is 4.1-fold higher than the sample without CuCl2. Additionally, this adsorbent shows a high propylene uptake of 2.38 mmol g-1 and a propylene/propane dynamic selectivity of up to 161 at 298 K and 1 bar. Aspen simulation suggests that a propylene purity of 99.9% can be achieved with a 70% recovery using a vacuum swing adsorption process. The enhanced performance is primarily attributed to the unique pore structures of the wood-structured carbon adsorbent.
