Hydrogen production from partial oxidation of methane in a membrane reactor

Abstract

Partial oxidation of methane was performed in a packed-bed reactor (PBR), packed-bed membrane reactor with a porous membrane distributor (PBMR#1), packed-bed membrane reactor with a Pd membrane separator (PBMR#2) and a dual membrane reactor equipped with membrane distributor and separator (DMR). Product with H 2/CO = 6 was obtained from the PBR operating within flammable region with a feed mixture of CH 4/O 2 = 1. Safer operation was obtained using the PBMR#1 by partitioning and adding the oxygen reactant through the membrane distributor. Continuous and selective permeation of H 2 by Pd membrane in the PBMR#2 allow the production of 97% pure H 2 stream, while simultaneously suppressing CO production. Carbon monoxide was absent in both the retentate and permeate streams of the PBMR#2. However, the Pd membrane in the PBMR#2 suffered from severe coking leading to membrane failure. The DMR showed that partitioning oxygen through the membrane distributor could ameliorate coking on the Pd membrane and improve hydrogen selectivity ( i.e., PBR = 45%, PBMR#1 = 60%, PBMR#2 = 60% and DMR = 75%). A 100-h monitoring showed that a stable hydrogen permeance rate and purity could be obtained from the DMR.