Development of selective adsorption process with various pore size A-type zeolite on removal of acetylenes for isoprene purification

Abstract

This study focused on the development of effective adsorbent to remove acetylenes for the purification of isoprene. The adsorbents with various pore sizes from 4 ？ to 5 ？ were prepared to investigate the effect of pore size on selective adsorption of acetylene as an impurity. The pore size of zeolite A was adjusted by ion-exchange between Na and Ca ions. The pore size of adsorbents has affected the removal of acetylenes selectively because of the kinetic diameter of acetylenes, such as 2-methyl-1-butyne-3-yen (IPA) and 2-butyne. In a batch adsorption experiment, 5A zeolite with pore size of 5 ？ showed the highest removal capacity of 2-butyne. However, IPA was hardly removed from isoprene by the A-type zeolites. For the adsorption isotherm, modified Langmuir model was well fitted with 2-butyne adsorption. Moreover, the regeneration of adsorbent was carried out to determine optimum method. The adsorbent heated for 12 h at 300 °C was regenerated significantly.