The process design and simulation for the methanol production on the FPSO (floating production, storage and off-loading) system

Abstract

A process for methanol production from 100 MM scfd of stranded gas and CO2 is proposed and simulated using a commercial process simulator, PRO/II v.9.1, for a FPSO (floating production, storage, off-loading) system. The process consists of wSteam-CO2 Reforming (SCR), methanol synthesis, a Reverse Water-Gas Shift (RWGS) reaction and ancillaries with recycle streams to SCR and RWGS. All reactors were simulated using the Gibbs reactor model. Also, the Plug Flow Reactor (PFR) model with reaction rate equations was used for the methanol reactor and the result was compared to the Gibbs reactor model. To maximize the use of the carbon source in stranded gas and CO2 while avoiding an undesirable increase in process size, the optimum recycle ratios were calculated with a satisfying constraint, a steam-to-carbon ratio >= 1 in the SCR. In the proposed Methanol-FPSO process the RWGS reactor can maximize CO2 utilization and case studies were performed to analyze the influence of RWGS. (C) 2013 Published by Elsevier B.V. on behalf of The Institution of Chemical Engineers.