Coal-derived Liquids CDL

The NiMo catalyst supported on nanoporous CB was compared with the commercial NiMo/Al203 catalyst and synthetic pyrite during the two-stage liquefaction of several coals.In this study the eifect of the tetralin/coal ratio on the yield of oil was the focus of attention. As expected, the yield of oil decreased with the decreasing tetralin/coal ratio. However, in every case, the NiMo/CB catalyst was the most active. Thus, even in the absence of tetralin, the yield of oil reached 52 and 64% after the first and second stage, respectively. Moreover, the 373 to 573 K fraction was the largest in the oil product obtained using the NiMo/CB catalyst. 

The slurry of coal with tetraline + toluene was mixed with a series of catalysts and tested in an autoclave at 643-763 K and 10-12 MPa. The catalysts were 

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Figure 4.2 presents a simplified flow diagram of the ENCOAL Liquid from Coal (LFC) process. The process upgrades low-rank coals to two fuels, Process-Derived Coal (PDF ) and Coal-Derived Liquid (CDL ). Coal is first crushed and screened to about 50 mm by 3 mm and conveyed to a rotary grate dryer, where it is heated and dried by a hot gas stream under controlled conditions. The gas temperature and solids residence time are controlled so that the moisture content of the coal is reduced but pyrolysis reactions are not initiated. Under the drier operating conditions most of the coal moisture content is released however, releases of methane, carbon dioxide, and monoxide are minimal. The dried coal is then transferred to a pyrolysis reactor, where hot recycled gas heats the coal to about 540°C. The solids residence time... 

The objective of this communication is to report structural information on a bituminous coal from a thorough characterization of its extracts. The characterization was carried out according to a scheme devised on the basis of our current understanding of coal chemistry. The scheme consists of considerations in preparation, fractionation, and analysis of coal-derived liquids (CDL) to obtain molecular-level information on the CDL per se as well as on the parent coal. The information obtained relates mostly to the structure of component clusters. 

Procedure A. Coal derived liquids (CDL) were obtained by hydrogenating dry powdered coal in a coiled-tube reactor (j)). 

A proper method of fractionation is indispensable in the study of the composition of coal-derived liquids (CDL). Data in Table II show large differences between solvent extraction and distillation as fractionation methods. Two fractions, ES and EI-AS, from ethanol extraction exhibited little differences from each other, while two fractions from distillation of ES revealed marked differences in molecular weight, H/C ratio, hydroxyl group content and physical appearance. 

Hydrotreatment (HT) of coal-derived liquids (CDL) is required to remove heteroatom constituents. These are reacted at high hydrogen pressures and high temperatures to hydrocarbons, H2S, NH and water. A typical catalyst is NiMo/alumina. 

Figure 2. PDMS for heavy coal-derived liquid produced from Clear Creek (Utah) high-volatile bituminous coal. The liquid was produced by hydrogenation at 10-20 s in a catalytic process. The test was based on University of Utah heavy CDL (HCG) No. 267-22 positive ion 4 ns/CH 20000 s.

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