Topsoe's sulphur tolerant water gas shift technology (sour shift) is used after the gasifier to convert part of the CO to H2. The shift conversion is adjusted to match the required CO/H2 ratio, depending on the end product.

The sour shift catalyst requires a certain minimum of sulphur in the feed gas to maintain its high activity.

Sour shift reaction features

The features of the sour shift reaction include

• flexible layout of the sour shift section due to a broad range of temperature and steam to carbon monoxide ratios 
• the sour shift catalyst allows operation at lower steam to carbon monoxide ratios than conventional high temperature shift catalysts resulting in lower steam consumption 
• high catalyst flexibility allows the use of adiabatic beds which are easy to operate and cost-efficient

Sour shift technology is a proven and efficient technology that is easy to operate.