Coal To Liquids: Can It Be Clean Energy?
Production of synthetic liquid fuels from coals via traditional technologies is commercially viable but with significant environmental problems. Indirect liquefaction proceeds via production of synthesis gas from coal, followed by Fischer-Tropsch synthesis of liquids. Based on carbon balance, a Fischer-Tropsch plant is basically a carbon dioxide factory that produces synthetic liquid fuels as a by-product. Direct liquefaction is theoretically a one-step production of liquids from coal, but usually the primary liquid product is similar to an aromatic, sour crude, requiring significant downstream upgrading. The EMS Energy Institute has developed a process for solvent extraction of coal followed by two-stage hydrotreating, which produces clean diesel and jet fuel. A conceptual design has been developed for making the process essentially emission-free, which could lead to the world’s first zero-emission CTL technology.
Harold Schobert was an active faculty member at Penn State for 25 years, and served at various times as director of the EMS Energy Institute and as chair of the Fuel Science program. He has held various offices in the Division of Energy and Fuels in the American Chemical Society, and has participated in numerous advisory committees at international, national, and state levels. He is the author of 13 books and about 150 peer-reviewed papers. Dr. Schobert currently works as an independent consultant and expert witness, and serves as Extraordinary Professor of Natural Sciences at North-West University in South Africa.