Process for producing a synthesis gas

Abstract

A process for producing a synthesis gas, comprising the steps of: (i) reforming a feed gas containing methane and an oxygen-containing gas in an autothermal reformer 24 (ATR) to produce a crude synthesis gas 28 at a temperature above 850 °C; (ii) cooling the crude synthesis gas 30 to 350 to 400 °C; (iii) passing the cooled crude synthesis gas 38 adiabatically through a first water gas shift vessel 40 (WGSR) to form a first hydrogen-enriched synthesis gas 20 at a temperature above 425 °C; (iv) cooling the first hydrogen-enriched synthesis gas (v) passing the cooled first hydrogen-enriched synthesis gas adiabatically through a second water-gas shift vessel 44 to form a second hydrogen-enriched synthesis gas 14, and (vi) cooling the second hydrogen-enriched synthesis gas 12 to generate a cooled second hydrogen-enriched synthesis gas 46; wherein the feed gas containing methane is preheated to a temperature of 375 °C or higher. The methane containing feed gas may be sourced from recovery loops of a hydrogen or methanol plant or may be natural gas. The first WGSR may have a high temperature catalyst and the second WGSR may have a high or medium temperature catalyst.

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