By Dr. James Smith, Eco-Tec Inc.
A number of commercial processes are available for removing hydrogen sulfide (H2S) from natural gas, tail gas from the Claus Process (containing un-reactive sulfur compounds, particularly CS2 and COS), coke-oven gas, pyrolysis gas and solution tail gas from heavy oil production. These processes are often limited by economics and technology.
In the economic range from about 0.1 to 20 tons sulfur per day, a new process affects the Claus Reaction in a single (pressure) vessel, not unlike the conventional amine acid gas absorption tower. Sulfur, in the form of large crystals, is removed by cooling a slipstream. Carbon dioxide is not absorbed, and water formed is carried out in the clean gas. This process does not emit any contaminants to the environment. The sulfur produced is in marketable form. This paper discusses the technology of this new, patented, sulfur purification process that offers clear economic and environmental advantages over current, conventional technologies.