Pretreated coal, analyses

Taking advantage of its high separation strength, a combination of SEC with MS enhances the capability of MS and makes it possible for the analysis of coal liquids. SEC can be used as a coal liquid sample pretreatment method prior to GC-MS. For SEC, 1-methyl-2-pyrrolidinone (NMP) is often used as eluent. Analytical result for a coal liquefaction extract sample prepared from SEC by GC-MS showed that only the pentane-soluble components could be analyzed [16] the larger aromatic molecules identified by SEC to be present were lost in the GC column. The molecular weight of the aromatics analyzed in the coal liquids were up to 352 with very few aliphatics. 

A modem direct coal liquefaction plant can produce about 0.5-0.6t of liquid fuel from every ton of dry coal. In the cases where the hydrogen supply is also produced from coal, the overall system can produce about 11 of liquid fuel from every 3—4t of coal. China Shenhua Coal Liquefaction Co. Ltd is currently building a 20,000 bbl/day direct coal liquefaction plant in Inner Mongolia, China. The economic viability of this large-scale direct coal liquefaction remains to be revealed. Economic analysis performed in 19903 showed that the process of the two-stage conversion of CTL has a product cost of 38 per barrel. Several areas, such as improved pretreatment and cleaning methods, novel catalysts, and improved hydrocarbon recovery, were identified as ways to lower the cost further.1... 

The activation of DNT has been shown to be a multistep process involving metabolism in the liver, excretion into the bile, deconjugation of metabolites and further metabolism by the intestinal flora, re-uptake (enterohepatic transport) of metabolites into liver, and finally activation and binding to cellular macromolecules in the liver [56], More recent studies [57] involving rats pretreated with coal tar creosote, which potentiates the genotoxicity of 2,6-DNT, elucidated a complex interaction that balances metabolic activation, uptake, and detoxification. The study monitored intestinal flora enzyme activities, bacterial analysis, mutagenicity of urine samples, HPLC analysis, and hepatic DNA adducts over a five-week exposure period. The location of nitroreductase activity was an... 

Materials evaluation in pilot plants covers all phases of the coal gasification process. Test specimens are installed in the coal pretreatment, gasification, gas quench systems, and methanation equipment in the plants. Three exposures, nominally 1, 3, and 6 months, at plant operating conditions are scheduled for each test location. Post-exposure corrosion evaluation employed in Phase II are the same as those used in other phases of the IITRI program, i.e., metallography combined with gravimetric analysis. 

Examples of the AAS analysis of powdered samples, as well as such solid foods as chocolate and flour, are presented in [ 137]. [ 138J. The direct determination of mercury in soils, coal, and ash is di.scussed in [139]. ICP—OES (and ICP—MS) can also be transformed into a direct process through solid sample introduction and electrothermal pretreatment [140J. 

During the first part of the nineteenth century considerable attention was paid to the chemistry of humic substances. A detailed description of the analysis of humic acid with particular reference to its acidic properties was given by Sprengel. One of his innovations still in vogue today was the pretreatment of soil with dilute mineral acid prior to its extraction with alkali. Sprengel also observed that after removal of all the mineral acid, freshly precipitated humic acid partially dissolved in cold water, but after drying, the humic material was converted into a less water-soluble form for which the term humus coal was proposed. 

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