Modeling of adsorber/desorber/catalytic reactor system for ethylene oxide removal

Abstract

The removal of ethylene oxide (EtO) in a combined system adsorber desorber/catalytic reactor has been investigated. The combined system was a modified draft tube spouted bed reactor loaded with Pt/Al2O3 catalyst. The annular region was divided into two sectons, the "hot" section contained about 7 % of catalyst and it behaved as a desorber and catalytic incinerator while the "cold" section, with the rest of the catalyst, behaved as a sorber. The catalyst particles were circulated between the two sections by use of a draft tube riser. The Computational Fluid Dynamics (CFD) program package FLUENT was used for simulations of the operation of the combined system. In addition, a one-dimensional numerical model for the operation of the packed bed reactor was compared with the corresponding FLUENT calculations. The results of the FLUENT simulations are in very good agreement with the experimental observations, as well as with the results of the one-dimensional numerical simulations.

U kombinovanom sistemu adsorber/desorber/katalitički reaktor izvršena su ispitivanja uklanjanja para etilen oksida (EtO). U kombinovanom sistemu je primenjen modifikovani fontanski sloj Pt/Al2O3 katalizatora sa cevnim umetkom. Anularni prostor sloja katalizatora se sastoji iz dve zone, "tople" zone koja sadrži oko 7 % ukupne količine katalizatora koja ima ulogu desorbera i katalitičkog konvertora, i "hladne" zone koja sadrži preostalu količinu katalizatora i ima ulogu adsorbera. Cirkulacija katalizatora između ove dve zone je omogućena pneumatskim transportom kroz cevni umetak. Izvršena je dvodimenziona parcijalna simulacija korišćenjem programskog paketa "FLUENT Computational Fluid Dynamics Software" u cilju simulacije odvijanja procesa u pojedinim zonama kombinovanog sistema. Jednodimenzioni model katalitičkog reaktora sa pakovanim slojem, iskorišćen je za numeričku simulaciju reakcionog dela kombinovanog sistema, i ovi rezultati su upoređeni sa odgovarajućim FLUENT-simulacijama. Dobijeno je veoma dobro slaganje rezultata FLUENT-simulacija sa eksperimentalnim zapažanjima i jednodimenzionim numeri čkim simulacijama.