Background: Natural gas consumption is large and growing worldwide. Compared to other fossil fuels, natural gas is advantageous environmentally and as an energy source because it burns cleaner, has a lower carbon footprint, and possesses a higher thermal efficiency. Before raw natural gas can be useful, several impurities must be removed or reduced to acceptable levels. Popular methods (amine absorption) for removing impurities carbon dioxide (CO2) and other impurities from natural gas are costly and environmentally disadvantageous. Membrane separation has also been employed to remove impurities from raw natural gas, but the membranes currently available are either incapable of removing key impurities or are not robust enough to handle the conditions common to natural gas extraction.
Technology: William Koros and Shouliang Yi from the School of Chemical and Biomolecular Engineering at Georgia Tech have developed a novel method for simultaneously removing CO2 and hydrogen sulfide from raw natural gas containing unacceptable levels of these impurities. The invention provides and utilizes a polymeric membrane that is grafted with silane agents to achieve adequate removal of CO2 and H2S from natural gas, biogas, and any other gaseous mixture containing those impurities. The membrane is comprised of a cellulose-based polymer, and the invention provides a method of enhancing the membrane by grafting with silane agents to yield properties a durable membrane capable of removing these key impurities and handling the conditions common to natural gas extraction.
Potential Commercial Applications: The invention is useful for extracting impurities, such as CO2 and H2S, from raw natural gas and making it suitable for pipeline delivery for industrial and household application. A large percentage of natural gas produced in the United States and natural gas reserves contain unacceptable levels of these contaminants. Unlike current methods and membranes, this invention provides a method for producing a novel membrane that can simultaneously remove these impurities in a cost effective and environmentally friendly manner.
Benefits / Advantages:
- The invention provides a simplified and lower cost device and method for simultaneously removing key impurities from raw natural gas
- The invention provides enhanced membranes that can remove impurities from any gaseous mixture
- The process is more environmentally friendly than existing alternatives