A process for cleaning gases from a gasification unit comprising the steps of: gasifying a fuel to raw synthesis gas comprising carbon monoxide and steam in a gasification reactor in the presence of a calcium-containing compound and steam removing halogen compounds from the raw synthesis gas catalytic conversion of carbon monoxide and steam in the raw synthesis gas to carbon dioxide and hydrogen in a water gas shift conversion step to provide a shifted gas contacting the shifted gas with a solid sulphur sorbent regenerating the solid sulphur sorbent by passing a stream of steam through the solid sulphur sorbent counter current to the flow direction of the shifted gas to provide a hydrogen sulphide-containing stream of steam transferring the hydrogen sulphide-containing stream of steam from the solid sulphur sorbent directly to the gasification reactor removing the cleaned shifted gas from the solid sulphur sorbent.