Liquid-Phase Guard Bed for Removal of Synthesis Gas Contaminants

This article describes a single guard bed that is effective for the removal of all poisons from a methanol synthesis process. The guard bed consists of a methanol synthesis catalyst suspended in a nonreactive liquid (a liquid-phase guard bed). The key to making the guard bed universal is operating the guard bed at a temperature below the operating temperature of the reactor but at a sufficiently high temperature and residence time to allow achievement of equilibrium with the incoming gas. The successful use of this guard bed is demonstrated for several catalyst poisons. In addition, the use of spent catalyst for the guard bed is demonstrated.