Coal extraction

In the United States there was Httie interest in solvent processing of coals. A method to reduce the sulfur content of coal extracts by beating with sodium hydroxide and zinc oxide was, however, patented in 1940 (116). In the 1960s the technical feasibiHty of a coal deashing process was studied (117),... 

Catechol is produced by coproduction with hydroquinone starting from phenol. Other techniques such as coal extraction remain marginal. The installed capacities (- 25,000 t/yr) are now sufficient to cover the demand. Catechol is mainly used for synthesis in food, pharmaceutical, or agrochemical ingredients. A specific appHcation of / fZ-butylcatechol is as a polymerisation inhibitor. 

Table 18. Effect of blending hydrogenated coal-dcrived pitch and coal extract on green coke yields, WVGS 13421...

Reneganathan, K., Zondlo, J. W., Mintz, E. A., Kneisl, P., and Stiller, A. H., Preparation of an ultra-low ash coal extract under mild conditions. Fuel Processing Technology, 1988, 18, 273 278. 

Wu, Z. Jernstroem, S. Hughey, C. A. Rodgers, R. R Marshall, A. G. Resolution of 10,000 compositionally distinct components in polar coal extracts by negative-ion electrospray ionization Fourier transform ion cyclotron resonance. Mass Spectrom. Ener. Fuels 2003,17, 946-953. 

The coals were crushed 80% less than 75 jjlm. The solvents used were anthracene oil (ex British Steel Corporation), hydrogenated process solvent (produced in a continuous coal extract hydrogenation plant) and several pure organic compounds (ex Koch-light). 

The present authors studied the solvolytic liquefaction process ( ,7) from chemical viewpoints on the solvents and the coals in previous paper ( 5). The basic idea of this process is that coals can be liquefied under atmospheric pressure when a suitable solvent of high boiling point assures the ability of coal extraction or solvolytic reactivity. The solvent may be hopefully derived from the petroleum asphaltene because of its effective utilization. Fig. 1 of a previous paper (8) may indicate an essential nature of this process. The liquefaction activity of a solvent was revealed to depend not only on its dissolving ability but also on its reactivity for the liquefying reaction according to the nature of the coal. Fusible coals were liquefied at high yield by the aid of aromatic solvents. However, coals which are non-fusible at liquefaction temperature are scarcely... 

The results of the two donor solvent experiments (E10 and E19) are discussed below. The coal extraction experiment (E20) is discussed in a subsequent section. 

The catalytic gas detector was originally developed in 1958 for the mining industry. It has become the standard means of detection worldwide in virtually all oil and gas operations. It is also used extensively in coal extraction and the chemical process industry. 

Analysis of coal extract with the ion-trap detector. Finnigan MAT Application Data Sheet ADS 12. 

Correctness of the sixth parameter equation (7) and its simplified forms for the generalization of the swelling data was proved for other coals including the Donbas coal [32] at the parameters B and VM- If to apply the equation (7) to the coal extraction data, then the factor of molar volume VM is insignificant, and the connection between quantities of extracted substance (in g/mole of the solvent) and physical-chemical characteristics can be satisfactorily described by fifth parameter equation (6) or by its simplified forms in this case possible acid-base interaction is the decisive factor, that is factor B [33 - 35], This confirmation is in good agreement with the above-said bigger molecules harder introduce... 

This approach is also applicable for the generalization of data concerning to the coal extraction under sub-critical conditions, but the role of the specific solvation is also insignificant, evidently as a result of its suppression at high temperatures. 

Flory Interaction Parameters for Illinois Number 6 Coal Extracts and Benzene... 

Finally, due to the extremely heterogeneous nature of coal, x parameters derived from Equation 1 can only represent at best an average interaction between a solvent and coal extract. It is also clear that pyridine extracts contain a substantial amount of low molecular weight material. Thus, an estimate of the degree of polymerization, x, which appears in Equation 1, is required. 

Prior to conducting the sorption experiment, the coal extract (200 mg) was first placed in a Wig-L-Bug capsule and ground for 1 minute under nitrogen. This grinding effectively reduces the extract to a fine powder, which is then used for the sorption experiment. Approximately 50-70 mg of the extract was then placed on the sample pan and the hangdown tube was replaced. The sample was maintained at 30.00 0.02 C by means of a constant temperature bath which surrounded the hangdown tube. 

We suggest that the rapid process corresponds to hole-filling and/or adsorption onto surfaces, and that the slow process, which follows first-order behavior, corresponds to swelling of the coal extract. Extrapolation of the linear portion of the curves shown in Figures 10 and 11 to time zero should yield the total uptake of benzene attributed to swelling. The results of this analysis are summarized in Table IV, where the total benzene uptake, M , and the uptake attributed to the hole-filling/adsorption and the swelling processes, and M., are shown. 

Production of Filtered Coal Extract Solution with Very Low Levels of Mineral Matter... 

Previous work in this laboratoiy (9-12) has shown that, by altering various parameters in the liquefaction process, the ash level of the filtered coal extract solution... 

One of the aims of the work carried out in this laboratory was to investigate the deposition of trace elements on the hydrocracking catalyst. To this end, a continuous laboratory hydrocracker was installed and, to provide feed material for this, a 2-1 autoclave and pressure filter were also installed. It was noticed on the initial runs with the autoclave that the ash level of the filtered extract solution was considerably lower, at 100-200 ppm, than that normally obtained by British Coal, at 500-600 ppm. The reason for this difference was not known, so an investigation was carried out which found that the lower ash levels could be produced by a higher digestion pressure. Table 1 shows some of the results obtained, which have b n previously published (10). Note that throughout all the experiments described in this paper the coals used were Point of Ayr and Calverton, whose analyses are given in Table 2, and that the HAO to coal ratio us was always 2 1. Hence, ash analyses in the coal extract solution are comparable. 

In another series of e q>eriments in this laboratory (U), it was found that the particle size of the coal fraction used affected the ash level in the filtered coal extract solution. In these e q>eriments, the coal sample, which is nominally < 200 pm, was divided into different size fractions by sieving, and each fraction digested using the normal procedure. Table 3 shows the results obtained with Point of Ayr and Calverton coals. Note that the Point of Ayr coal was a different batch to that used for the results described previously, with a simil analysis except for ash, which was higher at 19 %. 

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