COS (carbonyl sulphide) is gas which is naturally occurring or an off gas from chemical processing, natural gas and oil recovery, combustion of coal, biomass burning, etc. In high concentrations, COS can cause serious nervous system effects and acute respiratory failure. COS remains stable in air for many years eventually decomposing to sulphur oxides, which are known greenhouse gases.
Johnson Matthey offers a system of absorbents to remove COS, in line with our vision for cleaner and healthier world.
COS removal is commonly driven by process emission or purity requirements. For example, COS is typically counted as part of the total sulphur content and there might be a specification for the latter in duties such as olefin polymerisation. Under certain conditions, COS can liberate hydrogen sulphide which is highly toxic and corrosive.
Johnson Matthey’s solution for COS removal is a two-stage process: an initial hydrolysis step to convert COS to CO2 and H2S, and the subsequent absorption of the H2S using our market leading PURASPEC™ sulphur removal absorbents.
The performance of the hydrolysis catalyst depends on the temperature, pressure and concentrations of other impurities within the hydrocarbon stream. Johnson Matthey representatives should be consulted to determine which product is most appropriate for any given application/duty.