Research On Pressure Swing Adsorption To Recover Ethylene From Off-gas Of Ethylene Oxide Plant With Complexation Adsorbent

With the purpose of recovering ethylene from industrial off-gas of ethylene oxideequipment by pressure swing adsorption (PSA), two different adsorbents, activatedcarbon and self-made NJ adsorbent were researched. The research focused on theadsorptive capacity for ethylene, selectivity for ethylene/ethane separation, effect ofeach main component of several concentration ratios on the PSA performance forethylene of different adsorbents and regenerative performance of the adsorbents.Static adsorption isotherms of each monocomponent of the industrial off-gaswere measured on these two adsorbents by OMNISORPTION 100CX surface andvoidage measuring instrument. It showed that the adsorptive capacity formonocomponent ethylene on activated carbon was much greater than self-made NJadsorbent. The adsorption equilibrium data of ethylene and ethane could be properlyfitted by the models considering respectively physical adsorption and chemisorption.It had good consistency between model calculated value and experimental result.A single-column measurement equipment for dynamic adsorption was set up tostudy the PSA performance of the adsorbents by simulating the composition ofindustrial off-gas.It showed from the dynamic adsorption experiments for multicomponent gasmixture that under the same condition, the adsorbed amount of ethylene on activatedcarbon was greater than self-made NJ adsorbent, but its selectivity for ethylene wasvery low, which was under 1.0. The NJ adsorbent had a better selectivity for ethylenethan activated carbon did. The stability of the NJ adsorbent for PSA cycles was alsothe best. Meanwhile, it was studied that the feasibilities for industrial application ofNJ self-made complexation adsorbents, on recovery of ethylene from ethylene oxideoff-gas by PSA. The results indicated that the NJ adsorbent had high gasconcentration by desorption, great PSA stability and pressure swing regenerativeperformance, which was very good for industrial application.The NJ adsorbent was also proved by experiments that it could also be i戴岳:络合型吸附剂变压吸附环氧乙烷生产尾气中乙烯的研究 2004 年 5 月successfully regenerated by purging of inert gas and methane gas.According to the experimental results, the methodology for recovery of ethylenefrom the off-gas of ethylene oxide equipment was initially designed to select theappropriate PSA operation flowchart. It showed from the feasibility study forindustrial application that the recovered ethylene was pure enough and the percentrecovery was high. Compared to other methods, the recovery of ethylene by PSA hada marked economic effectiveness.