Coal liquefaction materials

DOE. 1986e. Effeets of eoal rank on the chemical composition and toxicological activity of coal liquefaction materials. Contraet no. DE-AC06-76RLO-1830. Washington, DC U.S. Department of Energy. Doeument no. DE86011015. 

In addition to supplying transportation fuels and chemicals, products from coal liquefaction and extraction have been used m the past as pitches for binders and feedstocks for cokes [12]. Indeed, the majority of organic chemicals and carbonaceous materials prior to World War II were based on coal technologies. Unfortunately, this technology was supplanted when inexpensive petroleum became available dunng the 1940s. Nevertheless, despite a steady decline of coal use for non-combustion purposes over the past several decades, coal tars still remain an important commodity in North America. 

Curlee, R. M., Materials Coatings for Valves Coal Liquefaction Components and Instrumentation, SAND82-2137, Sandia National Laboratories, Albuquerque, NM 87185 (1982)... 

In most cases, the inert materials are merely held together by matrices of the internally generated solids. It is important to recognize that there are two very distinct types of material generated by coal liquefaction namely carbonaceous (coke-like) solids and carbonates. 

Other Reaction Products. In addition to SRC, gas, light oil, and a filter cake of unreacted coal and inorganic materials are produced in the first step of the short residence time coal liquefaction process. One of the objectives of short residence time coal liquefaction is to minimize the loss of hydrogen to gases and light oil. 

McKee RH, Kapp RW Jr, Ward DP. 1985. Evaluation of the systemic toxicity of coal liquefaction-derived materials following repeated dermal exposure in the rabbit. J Appl Toxicol 5(6) 345-351. 

It has been known for some time that the yields of desirable products from coal liquefaction can be enhanced by dispersing the hydrogenation catalyst into the coal. For example, in the liquefaction of a high volatile bituminous coal, the total conversion to tenzene-soluble material, the asphaltene (hexane-insoluble), and oil yields were all enhanced when the catalyst was impregnated into the coal rather than mixed with the coal as a dry powder (2). In that work, impregnated salts of iron. 

Mueller, J. J., et al., Application of advanced materials and fabrication technology to let down valves for coal liquefaction systems, Electrical Power Research Institute Report, AF-305, January 1977. 

Coal liquefaction that can provide liquid fuels at the price of current petroleum (not cost but price) is one of the most important technologies that needs to be developed. The catalyst and control of its operating conditions are still key to technology for advanced coal liquefaction. The creative design of catalyst materials and reaction schemes is an important and challenging goal for the future. 

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)... 

Also, it should be noted that shale oil is predominently in the middle distillate boiling range with low residue and naphtha content. The absence of resid in coal liquids results from the severe hydrogenation conditions imposed in the coal liquefaction processes and the use of the remaining residue for hydrogen production. For shale oil, the retorting process destroys most the residual materials leaving a syncrude that is mainly a distillate. 

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. 

The software system, to meet the needs of the 1980 s, has wide flexibility and capabilities. For processes such as coal gasification or coal liquefaction, it can be used to perform steady state material and energy balances, calculate sizes of equipment, and carry out economic evaluations. Its flexibility can allow for the handling of coal or other solids in streams and equipment, and its capabilities allow for the simulation of many different types of process equipment and the calculations of physical properties under widely different conditions. Included in this is the ability to analyze conventional chemical and petroleum processes. Another valuable feature 1s a good preliminary cost estimation capability that permits the comparison of alternative processes on an economically consistent basis at an early stage of development. 

Furthermore, S-FFF has been applied to nuclear-energy-related materials [448,449] and Gr-FFF for residues from coal liquefaction processes [423]. 

In certain cases, such as the separation of PAHs obtained from a coal liquefaction process, using reversed-phase HPLC is complicated as sample preparation is elaborate. This is due in large part to the fact that most complex fuel-related materials contain compounds that are not usually soluble in acetonitrile, the solvent of choice in reversed-phase HPLC. Here, NPC, which employs a variety of solvents, offers an alternative to the analysis of such samples. Separation of five well-studied coal liquefaction process stream samples was achieved and 19 isomers were resolved when NPC was used [33]. The method employed a tetrachlorophthalimidopropyl-modified silica column (TCPP) with a charge-transfer mechanism. 

Hydrous titanium metal oxide catalysts are extremely versatile materials that have promise as direct coal liquefaction catalysts. Previous studies have shown that they perform well in both batch and bench-scale coal liquefaction tests. 

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