Hydroliquefaction of coal

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). 

Figure 8.3. Gas-Liquid Fluidized Bed C"Ebullating" Reactor for Hydroliquefaction of Coal CKampiner, in Winnacker-Kuehler, Chemische Technolagie 52, 19723. ...

Hydroliquefaction of Coal Liquids in Spinning and Falling Basket Autoclaves... 

Lanning, W. C. Green, J. B. Dooley, J. E. Catalytic Hydroliquefaction of Coals for Hydrocarbon-Type Analysis in Relation to Refining. ACS Div. Fuel Chem. Preprints, 1978, 22 (1), 62-70. 

FIG. 19-39 Gas-liquid-solid reactors, (a) Three-phase iluidized-bed reactor, b Ebullating bed reactor for hydroliquefaction of coal. (Kampiner in Winnacker-Keuchler, Chemische Technologie, vol. 3, Hanser, 1972, p 252.)... 

Table IX. Precipitation of Nitrogen Compounds by Application of Schemes A, B, and C to Products of Catalytic Hydroliquefaction of Coal in Anthracene Oil...

SRC II (Solvent-Refined Coal (SRC) II, Pittsburg and Midway Coal Mining Co.)—hydroliquefaction of coal with slurry recycle, 25.3 wt % on dry Western Kentucky coal, < 10 cP 850°F endpoint. 

Synthoil (U.S. Bureau of Mines—Bruceton)—catalytic hydroliquefaction of coal in a fixed-bed reactor, 59.3 wt % on dry West Virginia coal 30SSU 180°F 50% 850°F+. 

The hydroliquefaction of coal in the Bergius process is not a simple reaction or process in fact, it involves a series of organometallic transformation, such as insertion, migration, and reductive elimination. Therefore, only a small part of the reaction scheme is displayed here to show a possible conversion. 

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