What is the issue?
Natural Gas (NG) and Bio-Gas (BG) is extracted from a well and diverted through gathering pipelines to a treatment plant where the impurities are then removed to meet specific pipeline composition specifications. Methane (CH4) is commonly stripped using chemical processes like Pressure Swing Adsorption (PSA). This requires complex chemicals, heat, high electrical consumption, and associated mechanical equipment each with significant capital, operational and transportation costs. Chemical treatment plants are generally large permanent structures and therefore not suitable for installation at small-scale gas production operations. The inability to process gas locally to the production source (i.e. wellhead) contributes significantly to gathering pipeline costs and greenhouse gasses through routine gas flaring.
What is GreenTech Energy doing?
Membrane gas filtration has many beneficial uses across industry. The recent introduction of micro-turbines capable of combusting untreated gas and hydrocarbons straight from the well has disrupted some gas flaring practices. Our patent protected process takes feed gas and separates Methane from the remaining reject byproducts. The Methane may be injected direct into a pipeline, compressed or liquefied for further use. The rejected byproducts are then combusted by the micro-turbine to generate electricity and heat. Utilizing the waste heat from the turbine exhaust can drive efficiency up to 80%. Depending on the inlet gas composition, the byproducts may be further separated by another membrane array into different gas components eg CO2 for well reinjection or use as an improved fracking fluid as demonstrated in recent studies. CO2 has higher mobility than water, and, therefore, the injection pressure can be better delivered into the natural porosity of the formation. This changes the mechanism by which the fractures are created, generating more complex fracture networks that result in more efficient shale gas production. Benefits of CO2 fracturing also include eliminating the need for a hefty water supply (making fracking viable in arid locations), reducing the risk of damage to reservoirs (as often happens when aqueous solutions create blockages in the rock formation), and providing an underground repository for captured CO2. Alternatively dissolved CO2 may be injected into tanks using our air lubrication technology to induce growth in algae based bio-fuels such as those developed by Exxon. Downstream uses include purifying pipeline gas for small-scale liquefaction operations at ports and other underdeveloped locations.
What are the benefits of membrane technology?
Lower gas flaring, simplicity, cost, reduced operational service and zero chemicals are major benefits to membrane gas filtration. As membrane and system performance at high gas purity levels improves, membrane technology will potentially open up the small-scale LNG plants to meet Tier 4 emissions targets for oil field machinery, and increase the number of small marine LNG fueling facilities.
Courtesy of Generon: Process Gas Separation