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Chapter 22.4.18 Use of sulphur resistant catalysts for shift reaction of syngasfrom partial oxidationDescriptionThis is an integrated technique applicable in new partial oxidation plants. The technique allowsfor the removal of CO 2 and sulphur compounds, traditionally carried out in separate steps, to becombined into one step. In an ammonia plant using partial oxidation for syngas production, twobasic process configurations can be used. In one configuration, the syngas is cooled after thegasifier in a waste heat boiler. The H 2 S is subsequently recovered from the syngas in a coldmethanol wash unit. The cleaned gases are saturated with steam before entering the hightemperature shift reactor, using a conventional iron-based catalyst. After the shift reactors, CO 2is removed in a conventional CO 2 removal unit, for instance in a second stage cold methanolwash unit.In the second configuration, cooling of the syngas after the generator is carried out by a directwater quench, which also provides the steam needed for the shift conversion. In this case thecold methanol wash unit is placed after the shift conversion, removing CO 2 and H 2 S in twoseparated fractions. In this configuration, the feed for the shift conversion still contains all thesulphur in the syngas and so a sulphur tolerant shift catalyst is needed. Energy savings may beachieved in the second configuration, as it is not needed to reheat the syngas before the hightemperature shift.Achieved environmental benefits• energy savings.Cross-media effectsNot believed likely.Operational dataNo information provided.ApplicabilityThis is an integrated technique applicable to new partial oxidation plants.EconomicsNo information provided, but cost benefits can be assumed.Driving force for implementationCost benefits.References to literature and example plants[3, European Commission, 1997]82 Large Volume Inorganic Chemicals – Ammonia, Acids and Fertilisers