Gas-to-Liquid Process Optimization for Different Recycling Configurations and Economic Evaluation

Abstract

Synthesis gas production by the steam methane reforming process and its subsequent use in Fischer–Tropsch synthesis for gas-to-liquid applications is studied in this work. A base case of synthetic crude oil production is developed and is compared with three different alternative designs. Common tail gas recycling configurations from the Fischer–Tropsch products to the upstream units are investigated with and without carbon dioxide separation prior to the Fischer–Tropsch reactor in the three alternates. A kinetic model proposed for a nickel based catalyst is used for synthesis gas production and a cobalt based model is used for Fischer–Tropsch synthesis in the process simulation. Process optimization was carried out, for economic evaluation of different designs, subject to a well-defined and concise set of constraints. Economics of all four designs are evaluated by the Aspen Process Economic Analyzer for a comprehensive and meaningful comparison.