A comparative study between a fluidized-bed and a fixed-bed water perm-selective membrane reactor with in situ H2O removal for Fischer-Tropsch synthesis of GTL technology

In order to eliminate the pressure drop problem and mal distribution of the temperature profile along the reactors, fluidized-bed membrane reactors are proposed as an alternative for Fischer-Tropsch synthesis (FTS) in gas-to-liquid (GTL) technology. Regarding this, a novel cascading fluidized-bed membrane reactor (CFMR) is proposed in this study and compared with a fixed-bed membrane cascading with fluidized-bed membrane reactor (FMFMR). The CFMR configuration consists of a fluidized-bed water perm-selective membrane reactor followed by a fluidized-bed hydrogen perm-selective membrane reactor. The performance of CFMR is compared with FMFMR in order to investigate the effect of fluidization concept on the reactor performance. Unlike CFMR where a fluidized-bed concept is applied in the first reactor, a fixed-bed concept is used in the first reactor of FMFMR. The modeling results show 5.3% increase in the gasoline yield and 12% decrease in CO2 yield in CFMR in comparison with FMFMR owing to applying a fluidized-bed concept instead of a fixed-bed concept in which more effective temperature management is achieved. According to the modeling results, CFMR is superior to FMFMR for FTS in GTL technology owing to achieving excellent temperature control and a small pressure drop and consequently higher gasoline yield and lower CO2 yield. (C) 2011 Elsevier B.V. All rights reserved.