Hydrocracking of coal

Antimony trichloride is used as a catalyst or as a component of catalysts to effect polymerisation of hydrocarbons and to chlorinate olefins. It is also used in hydrocracking of coal (qv) and heavy hydrocarbons (qv), as an analytic reagent for chloral, aromatic hydrocarbons, and vitamin A, and in the microscopic identification of dmgs. Liquid SbCl is used as a nonaqueous solvent. 

Major work on zinc chloride catalysts for hydrogenation and hydrocracking of coal has been carried out by Zielke, Gorin, Struck and coworers at Consolidation Coal (now Conoco Coal Development Co.) (1). The emphasis there has been on a full boiling-point range of liquid product, from treatment at temperatures between 385 and 425°C and hydrogen pressures of 140 to 200 bars. 

A substantial program was also previously conducted in a batch autoclave unit on the direct hydrocracking of bituminous coal (1) with zinc chloride melts, but no work was done in either batch or continuous units on regeneration of spent melts from direct hydrocracking of coal. 

The fluid-bed combustion method (2) has been chosen, however, for process development in the regeneration of spent melts from the hydrocracking of coal. In this method, from one to two parts by weight of spent melt is generated for each part of coal fed to the hydrocracking process. The carbonaceous residue, sulfur, and ammonia retained in the melt are burned out with air in a fluidized bed of inert solids. The zinc chloride is simultaneously vaporized, the ash separated from the overhead vapors, and the zinc chloride vapor is condensed as pure liquid for return to the process. 

U. S. Dept, of the Interior. Interim Report No. 2, Research on Zinc Chloride Catalyst for Converting Coal to Gasoline—Phase I—Hydrocracking of Coal and Extract with Zinc Chloride, Vol. Ill, Book 1, March 1968. 

Hydrocracking of coal, coal oil, anthracene and phenanthrene was carried out in batch stirred tank reactors (Figures 1 and 2) in the temperature range 450 - 540 c under pressures up to 3500 psi. Reactor... 

Figure 2. Hydrocracking of coal. 1 and 2 Batch stirred tank reactor.

Product distribution data (Table V) obtained in the hydrocracking of coal, coal oil, anthracene and phenanthrene over a physically mixed NIS-H-zeolon catalyst indicated similarities and differences between the products of coal and coal oil on the one hand and anthracene and phenanthrene on the other hand. There were differences in the conversions which varied in the order coal> anthracene>phenanthrene coal oil. The yield of alkylbenzenes also varied in the order anthracene >phenanthrene>coal oil >coal under the conditions used. The alkylbenzenes and C -C hydrocarbon products from anthracene were similar to the products of phenanthrene. The most predominant component of alkylbenzenes was toluene and xylenes were produced in very small quantities. Methane was the most and butanes the least predominant components of the gaseous product. The products of coal and coal oil were also found to be similar. The most predominant components of alkylbenzenes and gaseous product were benzene and propane respectively. The data also indicated distinct differences between products of coal origin and pure aromatic hydrocarbons. The alkyl-benzene products of coal and coal oil contained more benzene and xylenes and less toluene, ethylbenzene and higher benzenes when compared to the products from anthracene and phenanthrene. The gaseous products of coal and coal oil contained more propane and butanes and less methane and ethane when compared to the products of anthracene and phenanthrene. The differences in the hydrocracked products were obviously due to the differences in the nature of reactants. Coal and coal oil contain hydroaromatic, naphthenic, heterocyclic and aliphatic structures, in addition to polynuclear aromatic structures. Hydrocracking under severe conditions yielded more BTX as shown in Table VI. The yields of BTX obtained from coal, coal oil, anthracene and phenanthrene were respectively 18.5, 25.5, 36.0, and 32.5 percent. Benzene was the most... 

The experimental data obtained in the hydrocracking of coal, coal oil and phenanthrene were tested with equations (iii) and (iv) as shown in Figures 8 and 9 and the data were found compatible with the model. This compatibility confirmed that the rates of hydrocracking were controlled by surface chemical reactions as were also indicated by arrhenius activation energies (Table VIII). 

Alkylbenzenes (BTX) are mainly made from petroleum and coal in the United States. Petroleum refineries produce about 95% of BTX and the rest comes from coal. Coal based BTX is obtained as a by-product from high temperature carbonization of coal employed for the production of metallurgical coke. Carbonization process yields only 2-3 gallons of BTX per ton of coal. BTX can be produced in larger quantities by hydrogenation and hydrocracking of coal (1,2). The organic... 

Hydrocracking of coal, coal oil, anthracene and phenanthrene was carried out in batch stirred tank... 

Sharypov V.I., Kuznetsov B.N., Beregovtsova N.G., Reshetnikov O.L., Baryshnikov S.V. (1996) Modification of iron ore catalysts for lignite hydrogenation and hydrocracking of coal-derived liquids. Fuel, 75, No 1, 39-42. 

Buchanan et alP" conducted model studies on the hydrocracking of coal by studying in detail the action of SbCb melts with (and in some cases without) AlCb on a,(i>-diphenyialkanes. They observed selective sp sp bond cleavage for the four classes of diphenylalkanes studied, as shown in equations (116) to (118). Notably, 1,3-diphenylpropane and 1,4-diphenylbutane gave only the indan and tetralin derivatives, respectively. 

C.W, Zielke and E. Gorin. Kinetics of Hydrocracking of Coal Extract with Molten Zinc Chloride Catalysts in Batch and Continuous Systems. lEC Proc. Des. Dev. (1969) 546. 

It will be an ultimate problem for hydrocracking of coal or heavy petroleum residues to transform effectively polycondensed aromatics to lower hydrocarbons. Two simplified model compounds of polycondensed aromatics were adopted, i.e., anthracene (ANT) which is linear and phenanthrene (PHN) which is angular cata-con-densed aromatics. Processes for degradation of these molecules to lower hydrocarbons, preferably to monocyclic aromatics, have been explored. 

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