Skip to content


for optimal performance


Active guard/ high-temperature sour shift catalyst

SSK-20 is a cobalt-molybdenum (CoMo)-based catalyst that is used in sour water-gas shift reactors in chemical and power-producing plants based on gasification of coal or petcoke. The SSK-20 catalyst is optimized for use in the guard and high-temperature sour shift reactors.

Combined poison protection and stable shift activity

SSK-20 is a special large-size version of TOPSOE™’s low-temperature sour shift catalyst, with a lower pressure drop and an excellent capacity for arsenic, iron carbonyl, and nickel carbonyl uptake. The SSK-20 catalyst is furthermore uniquely engineered to provide stable long-lasting shift activity in high-temperature applications.

Protection from dust

If dust or other impurities are present in the raw process gas, the GSSK sour shift guard material can be used to effectively protect the downstream SSK-20/SSK-10 catalysts.

Low-temperature sour shift catalyst

For downstream low-temperature sour shift applications, we recommend the installation of the SSK-10 catalyst.

Conversion of COS

SSK-20 will convert carbonyl sulfide (COS) to hydrogen sulfide (H2S); however, the COS slip will be defined by the temperature at the outlet of the sour shift section, and a low COS slip is favored by low temperatures. If a very low COS slip is required, the CKA-3 COS hydrolysis catalyst can be installed downstream of the sour shift catalysts and operated at a lower temperature.