Coal-derived materials

Surjit, S., Coke for the steel industry. In Proceedings cf the Corference on Coal-Derived Materials and Chemicals, ed. T. F. Tonies and C. L. Irwin. West Virginia Univesity, Morgantown, WV, 1991, pp. 1 14. 

In addition to knowing the total MTC solubility, it was important to determine the amount of methanol or other solvent retained by the MTC. This quantity, the incorporation ratio (R, gm incorporated organic material/gm coal-derived organic material), was determined by a carbon balance on the reaction. By assuming that any solvent retained in the dried MTC is pyridine-soluble, and subtracting it from the total dissolved material, the minimum solubility of the coal-derived material may be calculated. This quantity, the corrected solubility, is an indicator of the true solubilizing effect on the coal by the particular run conditions. ... 

Kilbane, J. J., and Jackowski, K., Biodesulfurization of Water-Soluble Coal-Derived Material by Rhodococcus-Rhodochrous IGTS8. Biotechnology and Bioengineering, 1992. 40(9) pp. 1107-1114. 

Generally, conversions to material bpt <450°C were in the range of 70-75%. These values would indicate that much of the coal derived material was ix)t converted under the conditions used and that a longer reaction time or a higher reaction temperature would be required to... 

Later, D. W., Nitrogen Polycyclic Aromatic Compounds in Coal-Derived Materials, in Handbook of Polycyclic Aromatic Hydrocarbons (A. Bjprseth and T. Ramdahl, Eds.), Vol. 2, Dekker, New York, 1985. 

Several other methods have been used to determine the trace elements in the mineral matter of coal, as well as in whole coal and coal-derived materials. These methods include spark-source mass spectrometry, neutron activation analysis, optical emission spectroscopy, and atomic absorption spectroscopy. 

Along similar lines, carbon-13 magnetic resonance has been applied to coal and to the elucidation of the character of soluble coal fractions and other coal-derived materials (Bartuska et ah, 1978 Ladner and Snape, 1978 Miknis, 1988). In fact, it is the advances in carbon-13 magnetic resonance that have brought new thoughts to the chemical nature of, and structural types in, coal. The technique brought with it the innovative solid-state techniques that allowed coal to be viewed in its natural solid state without invoking the criterion of sample solubility. This removed the need for dissolution of coal fractions and the often... 

Tandem mass spectrometry is also developing into an important analytical method for application to coal-derived materials (Wood, 1987). The analysis of heteroatom ring species and hydrocarbon species in coal-derived liquids offers indications of the location of the heteroatoms in, or on, ring systems, as well as indications of the hydrocarbon systems. 

Many of the feedstocks for the chemical industry, especially aromatic hydrocarbons, were originally obtained as by-products from the carbonization of coal. (1,2) However, nowadays, most of these chemical feedstocks are derived from petroleum. Nevertheless, it is probable that, within the next few decades, the shortage of world reserves of petroleum will mean that BTX will once again have to be produced from coal, as will ethylene. It is, therefore, appropriate to examine ways in which these materials can be produced from coal the present investigation was designed to study the formation of BTX and ethylene by the thermal cracking of coal-derived materials from the NCB coal liquefaction/hydrogenation processes. (3)... 

Unhydrogenated Coal-Derived Materials - Preliminary experiments on cracking the vapor from coal extract (B) at 1133°K for 0.7-8 s showed that the BTX yield peaked at 2 s whereas, ethylene was favored by shorter residence times. 

Figure 2. Effect of cracking temperature on yields from unhydrogenated coal-derived materials top, Linby coal middle, anthracene oil extract of Linby coal bottom, anthracene oil carbonizer temperature, 873 K vapor residence time, 2 s ...

Natural Gas Condensate - To compare the yields from coal-derived materials with those from a petroleum material, a full range, North Seal gas condensate (F) was cracked at 1158°K for 0.4 s. Its analysis is given in Table 1, and the yields obtained are listed in Table 2. More ethylene (30%) but less BTX (16%) were produced than from the highly hydrogenated coal materials ... 

The results from the thermal cracking of unhydrogenated and hydrogenated coal-derived materials, a gas condensate, and model compounds led to the conclusions that ... 

Hausler, D.W. and Taylor, L.T. (1981) Size exclusion chromatography of organically bound metals and coal-derived materials with inductively coupled plasma atomic emission spectrometric detection. Anal. Chem., 53, 1227-1231. 

It seems likely that aromatic amines which are found in liquefaction products have been produced by a combination of thermolysis and hydrogenation. There is no evidence for aromatic amines in coals from either selective oxidation degradations (22) or from direct X-ray Photoelectron Spectroscopy measurements (23). Oxidations would produce very stable nitroaromatics which are not seen. Another possible structure for this formula is phenoxazine(Vb). Such a molecule would not survive high temperature combined with long reaction times. Although annelated thiophene with a pyrrole(VI) would appear to be a likely structure in coal, there is no evidence for its existence in any of the coal derived materials. 

This paper describes the advanced engineering capabilities of ASPEN and demonstrates their use by means of an example problem. The advanced capabilities include the ability to model unit operations involving solids, the ability to compute the properties of coal and coal-derived materials, and great flexibility for the user to add specialized models or other computations. 

Characterization of Coal-Derived Materials by Matrix Isolation Spectroscopy... 

The identification and quantitative determination of specific organic compounds in very complex samples is an area of intense current research activity in analytical chemistry Optical spectroscopy (particularly UV-visible and infrared absorption and molecular fluorescence and phosphorescence techniques) has been used widely in organic analysis. Any optical spectroscopic technique to be used for characterization of a very complex sample, such as a coal-derived material, should exhibit very high sensitivity (so that trace constituents can be determined) and extremely great selectivity (so that fractionation and separation steps prior to the actual analysis can be held to the minimum number and complexity). To achieve high analytical selectivity, an analytical spectroscopic technique should produce highly structured and specific spectra useful for "fingerprinting purposes," as well as to minimize the extent of overlap of spectral bands due to different constituents of complex samples. 

For the direct excitation of fluorescence from low-temperature samples of coal-derived materials, without prior separation steps, use of a laser as the source appears absolutely essential ( 2, 17). 

To a limited extent electrochemical methods have been used to study coal extracts and coal-derived materials. Two examples are cited (50,51). 

Results of these tests are shown in Table IV. The average emissions values are shown for the coal-derived fuels. As previous testing has shown, the EDS fuel oils produced little particulate relative to the petroleum fuel, while the smoke values for the coal-derived materials were equal to or less than that of the RSFO. As with the laboratory testing, the N0X level was a function of the fuel nitrogen level, although N0X emissions from the commercial unit were lower than from the laboratory boiler. 

Precipitation of Coal-Derived Bases from Toluene. A solution of coal-derived material in toluene was prepared by stirring 50 g of sample per liter of solvent at reflux temperature for 6-8 h. After cooling, suction filtration through a sintered glass funnel was used to remove the undissolved solids, which were dried in vacuo at 80° C and weighed the quantity of material dissolved was determined by difference. The filtrate was placed in a stoppered bottle and used as a stock solution for several precipitation experiments. Immediately before the use of the toluene solution, an accurately pipetted volume was evaporated to dryness in vacuo and the remaining solid was weighed to calculate the concentration. 

Coal derived materials These products were obtained from our 1 kg h continuous reactor unit (7) as oils (X4 soluble) asphaltenes (tetralin soluble/X4 insoluble) preasphaltene (also known as asphaltol) (tetralin insolubles/tetrahydrofuran (THF) solubles) and THF insoluble materials for subsequent reactivity studies. 

Samples of each of the coal derived materials were reacted separately in the presence of several catalysts in a 70 ml batch autoclave using a 1 1 slurry of tetralinrmaterial at 425 C with an initial hydrogen pressure of 6 MPa for 1 hour at reaction temperature. The products from these reactions were separated into oils, asphaltenes, preasphaltene and THF insolubles. 

Thermal instability of coal derived materials leading to interconvertibility between products including retrograde reactions and the establishment of steady state conditions. The principle of reversibility is of importance in these processes. 

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