Mechanisms of Wave Liquefaction Conversion of Coal to Liquids for Reactor Refinement and Optimization

With 27% of the world’s coal reserves located in the United States, development of a clean, efficient, and economically viable pathway to coal utilization is of strategic importance. Development of advanced coal-to-liquids technologies provides this direct pathway, while improving energy security, reducing coal environmental footprint, and promoting economic development directly in the communities affected by the downturn in the coal industry. The microwave plasma technology under development presents a novel approach to the direct conversion of solid hydrocarbons (including coal and biomass) to value-added chemicals, liquid fuels and other materials. With no intrinsic CO2 emissions or water consumption, the low-cost, small-footprint microwave plasma process decidedly overcomes inherent economic and environmental challenges of the conventional coal liquefaction technologies. Modular design and scale-up through replication enable flexible plant deployment geared to meet site-specific production needs. Planned developments will expand technology applications to production of renewable, low-cost fuels from coal/biomass blends and woody biomass, while in the short term, these coal conversion plants will enable efficient and lucrative utilization of coal fines – a waste by-product of the coal preparation plants, - reducing or eliminating the need for hazardous coal slurry impoundment ponds. The current engineering pilot system was developed and used to demonstrate the process at throughput rate of several pounds of coal per hour. Conditions necessary to promote conversion are known, but the exact mechanisms driving the conversion are unclear. Improved understanding of the plasma chemistry and physics behind the conversion process will enable targeted optimization of process conditions and implementation of process control solutions. Proposed project will retrofit the microwave plasma reactor to enable online plasma and process diagnostics. Operating conditions and recorded data will be analyzed and correlated with the product yields and distributions. Based on the sensor integration solutions and developed correlations between process data and product properties, process control solutions will be proposed. These activities will support and enable Phase II process engineering and development of the optimized, commercial scale reactor equipped with an industrial process diagnostics and control system... Phases I and II will lead to subsequent deployment of a modular, mine-mouth 50-100 ton per day coal conversion plant within the next 2 to 3 years.
Summary: Microwave-enabled coal-to-liquids process presents a novel, cost-effective way to produce chemicals, fuels and other materials from domestic coal reserves without CO2 emissions. Development of process diagnostics and control methods is necessary to commercialize this technology, deployment of which will improve energy security, reduce coal environmental footprint, and promote economic development. Key Words: coal, coal to liquids, synthetic oil, coal tar, microwave pyrolysis, plasma