SYSTEM AND METHOD FOR PREPARING A SYNTHESIS GAS STREAM AND CONVERTING HYDROCARBONS

摘要

A system and method of operating a pre-reformer (12) in a gas-to-liquids plant at minimum steam/carbon levels in order to reduce the C2+ content is provided that allows for the efficient production of synthesis gas to be used in producing liquid hydrocarbons preferably through a Fischer-Tropsch synthesis. The process and system involves providing steam, natural gas having greater than 3 percent C2+, and possibly hydrogen to a pre-reformer (12) and converting a significant amount of the C2+ to methane and CO2 and then using a synthesis gas generator (14) to prepare a synthesis gas feedstock with about a 2:1 H2:CO ratio and without undue soot formation. The synthesis gas is used in a Fischer-Tropsch synthesis unit (16) to convert the synthesis gas to heavier hydrocarbons. Water, light hydrocarbons, and portions of the tail gas may be recycled in different embodiments.