A Membrane Process to Recover and Use Methane Emissions

Methane is an important global warming gas. Large amounts of methane and other light hydrocarbons are produced as solution gas in the production of oil, and as biogas from landfills and animal feedlots. Some of this gas is emitted directly to the atmosphere, some is flared, and some (from the very largest sources) is used as fuel in specially modified turbines or engines to generate electricity. The gas is not more commonly used in this way because most sources are small, and the gas is very impure. Membrane Technology and Research, Inc., proposes to develop a membrane process to separate and upgrade the gas. The treated gas will be a much cleaner, richer turbine fuel with which to generate electric power. If this process is to be successful, the systems must be rugged, reliable, and low in cost. This project focuses on adapting current technology to meet these targets. The best application is to treat solution gas formed during oil production operations. The process achieves a simple payback time of only 2.3 years from the value of the heavy hydrocarbon liquids recovered and the electric power produced. There is a total potential market for about 10,000 of these units in North America. Treatment of biogas has a payback time of approximately 5 years. The market for these units will depend on acceptance of regulations requiring these gas emissions to be treated. If successfully developed, the process could be applied very widely. The first target market is to treat gas currently flared in natural gas operations. The second market, treatment of biogas from small landfills and animal feedlots, will be developed later.