Char-Oil Energy Development Process

The liquid products are filtered to remove particulate matter and then hydrotreated (370°C-425°C [700°F-800°F] 1750-2500 psi hydrogen) to produce a synthetic crude oil (Table 19.1) from whieh the majority (90%) of the nitrogen, oxygen, and sulfur have been removed. As already noted for the Lurgi-Ruhrgas process, the majority of the sulfur originally in the coal occurs in the char and, therefore, combustion of the char may be an environmental problem unless there is some effort made to install stack gas cleaning equipment. 

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Char Oil Energy Development Process U.S. Department of Energy Exxon Donor Solvent Process fluidized bed combustion hydrogenated anthracene oil hydrogenated phenanthrene oil Hydrocarbon Research, Inc. 

Charging, batteries, 3 410 CHARM analysis, 11 519-520 Char Oil Energy Development (COED) process, 6 853... 

In the char-oil energy development (COED) process (Figure 19.3), crushed coal (0.125 in. [3 nun]) is dried and heated to successively higher temperatures in a series of reactors, which results in the incremental removal of volatile matter from the coal (Jones, 1973, 1975 McCray et al., 1979). The maximum temperature of each reactor has to be carefully controlled so that it r ains appreciably lower than the temperature at which the coal will cake (or agglomerate), thereby reducing the effectiveness of the individual fluidized beds. Thus, reactor temperatures and the number of reactors are dictated by the character of the coal feedstock in the final reactor, the product char is used to generate heat for the process. 

Direct liquefaction processes under development are typically carried out at temperatures from about 450 to 475°C and at high pressures from 10 to 20 MPa and up to 30 MPa. Despite the slow rate at which liquefaction proceeds, the process itself is thermally rather efficient, since it is only slightly exothermic. However, hydrogen must be supplied and its manufacture accounts for an important fraction of the process energy consumption and cost of producing the liquid fuel. The hydrogen itself may be produced, for example, by the gasification of coal, char, and residual oil. 

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