Coal, hydrocracking

Work has also continued on the solvent-refined coal + hydrocracking concept (the NT.SL, or non-integrat-ed, two-stage liquefaction process), and a pilot plant was operated by Amoco, DOE and the Electric Power Research Institute (EPRI) from 1974 to 1992. 

The proportions of ZnCl f/NH3 and ZnCl2 j/NH4C1 depend on the ratio of nitrogen to sulfur in the feed. In addition to these inorganic compounds, the catalyst leaving the hydrocracker also contains residual carbon that cannot be distilled out of the melt. In the case of direct coal hydrocracking, the catalyst also contains the coal ash. 

Inspections on the four mid-distillates are presented in Table II. The 560°F endpoint for the H-Coal mid-distillate is caused by the fact that the 560° F+ material was delivered as process residue containing the ash and unreacted coal. The residue material was very difficult to distill in a batch system. Scheduling pressures forced the H-Coal hydrocracking runs to be done on the available material. 

In an effort to obtain higher value products from SRC processes, a hydrocrackiag step was added to convert resid to distillate Hquids. The addition of a hydrocracker to the SRC-I process was called nonintegrated two-stage Hquefaction (NTSL). The NTSL process was essentially two separate processes ia series coal Hquefaction and resid upgrading. NTSL processes were iaefficient owiag to the inherent limitations of the SRC-I process and the high hydrocracker severities required. 

British Coal Corp. is developing a gasoline-from-coal process at a faciUty at Point of Ayr (Scotiand). This process involves treatment with Hquid recycle solvents, digestion at 450—500°C, filtration to separate unconverted residues, and separation into two fractions. The lighter fraction is mildly hydrotreated, and the heavier one is hydrocracked (56). 

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. 

During World War II German scientists developed a method of hydrogenating soHd fuels to remove the sulfur by using a cobalt catalyst (see Coal CONVERSION processes). Subsequently, various American oil refining companies used the process in the hydrocracking of cmde fuels (see CATALYSIS SuLFUR REMOVAL AND RECOVERY). Cobalt catalysts are also used in the Fisher-Tropsch method of synthesizing Hquid fuels (21—23) (see Fuels, synthetic). 

Cobalt—molybdenum alloys are used for the desulfurization of high sulfur bituminous coal, and cobalt—iron alloys in the hydrocracking of cmde oil shale (qv) and in coalhquefaction (6). 

Magnitudes of /cg, /cp, /c, and indicate the importance of direct reactions with coal, where and are for hydrocracking reactions in the conversion process. Data for and from the experiments with HPO indicate that oil production from coal is increased by the use of a good hydrogen donor solvent. 

Gasoline, coal solvent extn, hydrocracked naphtha... 

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. 

Products Company and Davison (W.R. Grace) Catalysts) and Hydrocarbon Technologies, Inc. ART provides non-zeolitic catalysts for ebullating residue hydrocracking and fixed bed pretreating HDT [140], A nanoscale iron based, slurry catalyst is recommended for coal liquefaction, while a molecule-sized and chemically in situ generated catalyst is employed for the high conversion of asphaltenic fractions or heavy oils [141],... 

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

Hydrocracking, 30 48-52 behavior, thermal, 29 269 catalytic, 26 383 deethylation, 30 50 demethylation, 30 50 metallocarbene formation, 30 51-52 of f -decane, 35 332-333 primary coal liquids, 40 57 procedure, 40 66-67 product distribution, 30 49 reactions, over perovskites, 36 311 suppression by sulfur, 31 229 zeolite-supported catalysts, 39 181-188... 

All the hydrocracking/hydrogenation experiments were carried out in 500 ml capacity spinning type autoclaves. Two autoclaves of this design were used and the autoclaves were compared in experiments using the model compound phenanthrene, chosen because phenanthrene and its hydro-derivatives represent a large proportion of the solvent which is recycled in coal liquefaction processes. 

Table V summarises the data of the sulphur analysis of the hydrocracked liquids and the various bpt fractions for CoMo and NiMo catalysed experiments. The sulphur contents of neither the total hydrocracked liquids nor the individual bpt fractions showed any dependence on repeat contact or catalyst type. The values did show that the sulphur concentrated in the recycle solvent fraction (275-450°C), suggesting that, even under the relatively strong conditions used, certain sulphur-containing compounds will survive to be recycled in the solvent However, the sulphur content of the coal liquid feed was reduced by about 50% and the sulphur content of the likely upgradable product was low.

---