Coal liquefaction process developed

W. R. Eppedy and J. W. Taunton, "Exxon Donor Solvent Coal Liquefaction Process Development," paper presented at Coal Dilemma II ACS Meeting, Colorado Spriags, Colo., Feb. 12, 1979. 

Epperly, W. R. (Project Director). "EDS Coal Liquefaction Process Development—Phase IV", Annual Tech. Rept. for July 1978-June 1979 from Exxon Research and Engineering Company to U.S. Department of Energy and Electric Power Research Institute under Contract No. EF-77-A-01-2893, September 1979. 

W. P. Epperly and T. W. Taunton, "Exxon Donor Solvent, Coal Liquefaction Process Development", Proceedings of the 13th Intersociety Energy Conversion Engineering Conference, Vol. 

Exxon Donor Solvent, Coal Liquefaction Process Development... 

Epperly, W.R. Taunton, J.W., Exxon Coal Liquefaction Process Development, paper presented at the Thirteenth Intersociety Energy Conversion Engineering Conference,... 

Flash Pyrolysis Coal Liquefaction Process Development, FE-2244-4, Quarterly Report for July-Sept. 1976, Occidental Research Corp., Irvine, CA, 1976, pp. 35-41. 

IG-NUE A coal liquefaction process developed by Bergbau-Forschung in Germany during World War II. Catalytic metal salts were impregnated in, or precipitated on, the coal. A pilot plant was to have been built in Westphalia in 1977. 

Ireland Mine hvAb coal was used in the coal pyrolysis studies. The method of heat treatment was essentially that reported by Petrakis and Grandy (8), Ireland Mine coal was also the feed coal used to obtain most of the coal liquefaction products. The coal-derived liquids investigated were centrifuged liquid products (CLP) and their subfractions from selected runs in the Pittsburgh Energy Technology Center s 400-lb coal/day coal liquefaction process development unit (PDU) (9). 

Different types of other coal liquefaction processes have been also developed to convert coals to liqnid hydrocarbon fnels. These include high-temperature solvent extraction processes in which no catalyst is added. The solvent is usually a hydroaromatic hydrogen donor, whereas molecnlar hydrogen is added as a secondary source of hydrogen. Similar but catalytic liquefaction processes use zinc chloride and other catalysts, usually under forceful conditions (375-425°C, 100-200 atm). In our own research, superacidic HF-BFo-induced hydroliquefaction of coals, which involves depolymerization-ionic hydrogenation, was found to be highly effective at relatively modest temperatnres (150-170°C). 

The significance of the above-described work is that in all of the presently developing coal liquefaction processes, the initial step in the conversion is thermal fragmentation of the coal structure to produce very fragile molecules which are highly functional, low in solubility, and extremely reactive toward dehydrogenation and char formation. A more detailed discussion of the chemical nature of these initial products has been presented elsewhere (4). ... 

The type of quantitative analytical data which are needed for modelling and kinetic studies on coal liquefaction process could not be obtained by using general analytical techniques. We have developed a new analytical approach for obtaining qualitative information as well as quantitative data on coal liquid species. Coal liquefaction produces smaller molecules from coal which is composed of larger molecular species or a matrix of larger molecular species in which smaller species are entrapped. 

The SRC-II process is one of several coal liquefaction processes currently under development in programs funded by the Department of Energy (DOE). Product from this process is a distillate that is relatively attractive as a feed for conversion to transportation fuels. Essentially all of the nitrogen, sulfur, and oxygen can be removed in a single catalytic hydro-treating stage to yield a naphtha that is an excellent feed for a catalytic reformer and a middle distillate fraction that is a... 

This paper describes the status of the development of the Exxon Donor Solvent (or EDS) coal liquefaction process. It includes an overview of the jointly funded project and a brief description of the EDS process. It also includes a discussion of the project status, including a description of coal feed flexibility, hydrogen and fuel gas production alternatives and the progress in the construction of the 250 T/D pilot plant. Other communications have covered the R D program, the outlook for commercialization, and the organization of the EDS Project (1,2, 3,, 5, 6, J) ... 

In the development of coal liquefaction processes considerable effort has been concentrated on the coal liquefaction part of the process. In contrast, less effort has been directed toward utilization of the coal liquefaction residue or vacuum tower bottoms. 

Several processes have been developed for coal liquefaction. Large-scale pilot plants have been in operation for the solvent-refining coal (SRC) process, and a pilot plant is being constructed for the H-Coal process, which is a direct catalytic process. Construction of demonstration plants is under consideration. The coal liquids produced from the current processes contain large amounts of residual fuels. They probably will be used initially as boiler fuels for stationary power plants. However, the nitrogen content of coal liquids is much higher than the petroleum residual fuels. The sulfur contents of coal liquids can vary considerably they depend on the type of coal and the liquefaction process used. Current coal liquefaction processes are capable of produc-... 

Exxon Donor Solvent Also known as EDS. A coal liquefaction process in which coal in solution in tetrahydronaphthalene is hydrogenated, using a cobalt-molybdenum-alumina catalyst. So called because the hydrogen is donated by the tetrahydronaphthalene to the coal. Developed from the Pott-Broche process. Piloted by Exxon Research Engineering Company in the 1970s and operated at 250 tons per day in the Exxon refinery in Baytown, TX, from 1980 to 1982. 

LSE [Liquid Solvent Extraction] A coal liquefaction process, under development in 1990 by British Coal, at Point of Ayr, North Wales, now closed. The coal is dissolved in a coal-derived hydrocarbon solvent and then catalytically hydrocracked. 

NEDOL [New Energy Development Organization Liquefaction] A coal liquefaction process in development in Japan by the New Energy and Industrial Technology Development Organization (NEDO), Tokyo. Crushed coal is mixed with a pyrite catalyst and slurried in a hydrogenated heavy oil. Liquefaction takes place at 450°C, 170 bar. The overall oil yield is 59%. The used solvent is hydrogenated and recycled. Piloted in Kashima, Japan, in 1997 to 1998. Two Chinese companies were licensed to build test units in 2006. 

In the areas of fuel production and utilization the focus is in two directions the search for an unsupported catalyst for use in direct coal liquefaction processing, and the development of catalysts capable of generating specialty l roduct chemicals from coal and petroleum feedstocks. 

Past efforts in developing coal liquefaction catalysts have focused on alumina-supported systems and, except for exploratory studies, little attention has been given to systematic development of novel formulations. A particularly promising approach to the development of new catalysts specifically designed lor coal liquefaction processes lies in the formulation of multicomponent systems that, in comparison to work on single or bimetallic systems, are essentially unexplored. Use of multimetallic systems offers the possibility of multifunctional catalysts that are needed to perform the many different reactions encountered in coal processing. Because of its versatility for the preparation of multimetallic catalysts, the HTO system is an excellent candidate for further development. 

Conventional liquefaction processes developed for Eastern bituminous coals might not be the best choice for Western low-rank coals because of the substantial property and structural differences between them. In general, low-rank coals are more susceptible to reaction with H2, CO, or H2S. 

The coal liquefaction process from which experimental liquids were derived is the H-Coal technology (1,2) developed by Hydrocarbon... 

In the 1960s, two direct coal liquefaction processes were under development in the U.S. the Exxon Donor Solvent (EDS) process and the H-Coal process. The distinguishing feature of the EDS process was a separate solvent hydrogenation step to carefully control the hydrogen donor characteristics of the solvent. The most important feature of the H-Coal process was the emulated bed reactor in the process. 

The first direct coal liquefaction process was developed and patented by Bergius from Germany in 1913 and, therefore, is often referred to as the Bergius process. The world s first industrial-scale direct coal liquefaction plant was built in Leuna, Germany, in 1927 with an annual fuel production of 10,0001. By 1939, Germany built 12 direct coal liquefaction plants with a combined annual fuel production of about 4.23 million metric tons, which supplied about 70% of the aviation fuel and 50% of the transportation fuel for German troops during World War II. 

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