Simulation and optimization of an integrated GTL process

Abstract

Gas to Liquid (GTL) process involves the chemical conversion of natural gas into synthetic crude that can be upgraded and separated into different useful hydrocarbon fractions including liquid transportation fuels. Generally, GTL process includes of four units: 1) Synthesis gas production 2) Gas sweetening 3) Fischer Tropsch synthesis (FTS) 4) Product separation. In this study, an optimized integrated GTL process for converting of natural gas to valuable hydrocarbons such as gasoline and diesel fuels has been proposed. Steam & CO2 methane reforming, Amine gas sweetening, and FTS based on fixed bed reactor have been considered for simulation of integrated GTL process. In simulation step, all units were optimized, separately. Recycling of unconverted and light gas to suitable point has been investigated and optimized. Results showed that the total productivity was changed versus recycle of light gases to various point in same conditions. So, optimization process for integrated GTL plant was done. In optimization step, productivity and split ratio of recycled gas between several units were selected as single objective function and decision variable, respectively. Optimization results showed in recycle gas split ratio of 13:87 between amine and reforming units, GTL process has highest productivity value.