This Small Business Innovation Research Phase I project will develop a novel membrane for hydrocarbon separations. The initial focus of the project is the development of a selective membrane for efficient separation of hydrocarbons from methane in natural gas processing and separation of hydrocarbons from hydrogen in refinery applications. The chemically robust polymeric membrane will be of a composite configuration comprised of a hollow fiber porous support with a superimposed separation layer that is several hundred angstroms thick. The nano-structured morphology of the separation layer will enable selective fractionation of hydrocarbon molecules.
The broader impact/commercial potential of this project will be reduced energy consumption in separation and purification of hydrocarbons in oil, gas, and petrochemical industries. The environmental benefit is the associated reduction in emissions of green house gases methane and carbon dioxide. The technology will effect molecular level separation of hydrocarbons and will be capable of operation in harsh environments and high temperatures. A large initial market with an immediate impact for hydrocarbon selective membrane technology is the recovery of natural gas and hydrocarbon liquids from associated natural gas (gas generated during oil production) currently flared at remote geographic locations. Development of the proposed technology will enable recovery of the methane and high value hydrocarbons at the well with extensive economic and environmental benefits. The membrane is expected to find broad utility in high value gas and liquid separation applications including hydrogen recovery from refinery fuel gas, olefin/paraffin separation and generic hydrocarbon fractionation.
PoroGen Corporation, 6C Gill Street, Woburn, MA, 01801 NSF Award Number: 0944820 NSF Program Manager: Dr. Ruth Shuman Principal Investigator: Dr. Yong Ding Phase 1 and 1B Performance period: 1/1/2010 – 12/30/2010 Hydrocarbon separations are at the core of the chemical and petrochemical industries and are carried out almost exclusively by distillation or deep refrigeration. Distillation is energy intensive and does not scale down efficiently which can lead to underutilization of hydrocarbon feedstock. For example, a number of hydrogen containing streams in refineries are currently used as a fuel due to the lack of efficient hydrogen/hydrocarbon separation technology. Large volumes of natural gas generated during oil production (associated gas) are flared due to the lack of an efficient separation technology that can treat the gas at the well head. Membrane technology can be energy efficient and it is very compact. The technology is ideally suited for treatment of natural gas at isolated geographic locations and on off shore platforms. However, poor separation efficiency and the lack of chemical durability have limited membrane utilization in hydrocarbon separation applications to date. The overall objective of this Phase 1 NSF SBIR program was to develop a comprehensive membrane separation platform for a broad spectrum of hydrocarbon separations. This objective was successfully accomplished by developing a novel composite polymeric membrane comprised of ultra-thin separation layer formed from a nanostructured polymer superimposed on a porous hollow fiber support formed from advanced engineering polymer polyether ether ketone (PEEK). The composite membrane exhibits reverse permeation characteristics, i.e., the membrane permeates larger hydrocarbon molecules faster than smaller size hydrocarbons in contrast to conventional glassy polymeric gas separation membranes that preferentially permeate smaller molecules. The membrane structure and its separation characteristics are shown schematically in Figure 1. In Phase 1 of the program, PoroGen Corporation, PGC, has successfully demonstrated the technical and economical feasibility of preparing the novel composite hollow fiber membrane. Defect free composite membranes were prepared and their hydrocarbon separation performance measured. Bench scale membrane modules were constructed and their separation performance evaluated utilizing multiple hydrocarbon mixtures. The hydrocarbon gas separation performance was evaluated with both pure and mixed gas feeds. The composite membrane exhibited exceptional hydrocarbon separation characteristics. For example, butane/methane separation factor as high as 18 was demonstrated for natural gas feeds with high C3+ hydrocarbon content at ambient operating temperatures. Initial process design and economic analysis was completed. The analysis indicates that the membrane process utilizing the novel membrane is more economical in terms of capital cost and operating cost as compared to the conventional propane refrigeration process. In the Phase 1B part of the program, PGC designed and constructed several pilot size membrane modules equipped with nanostructured composite hollow fiber membranes. The module ability to purify natural gas was filed tested. The results of Phase I and Phase 1B programs have demonstrated the feasibility of preparing the polymeric nanostructured composite membrane, the feasibility of manufacturing scale up and the improved hydrocarbon separation efficiency by the novel membrane. The results provide the foundation for product optimization and product development scale up to be carried out in Phase II of this program.
