PRODUCTION OF LOW SULFUR SYNGAS FROM NATURAL GAS WITH C4+/C5+ HYDROCARBON RECOVERY

摘要

Sour natural gas is processed to remove the sulfur compounds and recoverC4+/C5+ hydrocarbons by scrubbing the gas with an aminesolution to remove most of the sulfur, followed cooling the gas to removeC4+/C5+ hydrocarbons and more sulfur compounds as liquidcondensate to produce a gas having less than 20 vppm of total sulfur. Thecondensate is sent to a fractionator to recover the C4+/C5+hydrocarbons. The sulfur and hydrocarbon reduced gas is contacted first withzinc oxide and then nickel, to produce a gas having less thanvppb of total sulfur which is passed into a synthesis gas generating unit toform a very low sulfur synthesis gas comprising a mixtureof H2 and CO. This synthesis gas is useful for hydrocarbon synthesis withincreased life of the hydrocarbon synthesis catalyst and greaterhydrocarbon production from the hydrocarbon synthesis reactor. Contacting thesynthesis gas with zinc oxide further reduces the sulfurcontent to below 3 vppb.