Techno-economic assessment of Fischer-Tropsch synthesis and direct methane-to-methanol processes in modular GTL reactors

摘要

The aim of this study is to perform a techno-economic assessment of the Fischer-Tropsch synthesis (FTS) process in a microchannel reactor (MCR) to produce clean syncrude, and the Direct Methane to Methanol (DMTM) process in a compact plant footprint. The operational and economic performances of the two processes were modeled using the Aspen HYSYS v7.2. The operational performance parameters include products yield and the economic performance parameters include net present value (NPV), payback period (PBP) and internal rate of return (IRR). In addition, the effects of tailgas recycle ratios and water integration on the performances of the FTS process and the effect of methane recycle ratios on the performances of the DMTM were investigated. The simulation results showed that the unit cost of the DMTM process was sensitive to the methane recycle ratio, however, that of the FTS in MCR was less sensitive to the tailgas recycle ratios. In order to maintain an IRR > 10 %, the tail gas recycle ratio of the FTS in MCR had to be greater than 8 % and 30 %, at CO conversions of 80 % and 72 %, respectively, whereas in the DMTM process, a minimum methane recycle ratio of 60 % was required to achieve any profitability. In addition, the DMTM process appeared to have significantly higher net energy requirements per product yield when compared with those of the FTS in MCR process; however, both processes had higher energy requirements than those of conventional GTL technologies.