One exemplary embodiment can be a process for removing carbonyl sulfide in a gas phase hydrocarbon stream. The process may include combining the gas phase hydrocarbon stream with another stream including an alkali and an alkanolamine, and passing the combined stream to a prewash zone including a vessel. The gas phase hydrocarbon may include carbonyl sulfide, and the alkali can include at least one of potassium hydroxide, sodium hydroxide, and ammonia. Usually, the vessel contains a contacting zone and a coalescing zone for removing the carbonyl sulfide.