A cheaper way to convert natural gas to liquid fuel
Production from methane of a precursor to liquid fuel called syngas, or synthesis gas, is one of the most costly steps of conventional routes to gasoline. Scientists working on the EU-funded project NEXT-GTL (Innovative catalytic technologies and materials for next gas to liquid processes) examined the main cost and technical challenges associated with conventional gas-to-liquid (GTL) processes. Researchers explored novel routes for catalytic syngas production from natural gas. They also investigated direct catalytic conversion (without the syngas intermediary) of methane to methanol/dimethyl ether (DME) and to aromatic compounds – organic molecules having one or more six-carbon rings such as benzene. In order to reduce the costs associated with syngas production, scientists developed a novel and advanced multi-stage process. This exploited catalytic partial oxidation (CPO) of natural gas together with gas separation membranes. Developed catalysts and membranes were tested in a pilot plant facility for comparison with semi-commercial ones. Eliminating the syngas production step is another promising route to decreased production costs of liquid transportable fuels, both gasoline and diesel. Scientists therefore explored routes for direct, low-temperature catalytic conversion of methane into methanol and extensively investigated suitable methane activation sites. Researchers also studied direct catalytic conversion of methane to aromatics that can be upgraded (by chemically combining with ethane or propane in a so-called alkylation reaction). Important progress was also made in the development of novel active and stable catalysts, both for aromatisation of methane and for benzene alkylation. In addition, project partners developed selectively permeable membranes and separation technologies for H2, O2 and CO2. These could be used in a variety of other refinery, petrochemistry, combustion and other non-chemical processes to increase their efficiency. NEXT-GTL successfully developed novel cost-effective and efficient methods for catalytic conversion of methane to liquid fuels for the transportation sector. Significant cost reductions will truly make GTL a viable alternative to traditionally less costly production of liquid fuels from crude oil, with important benefits for the environment and industry.
Keywords
Methane, syngas, NEXT-GTL, gas-to-liquid processes, methanol/dimethyl ether, DME, aromatic compounds, catalytic partial oxidation, alkylation reaction, selectively permeable membrane
