Coal-derived liquids analysis

LC-MS has been used to study various aromatic fractions from coal derived liquids, and there are also a number of reports on its use in the analysis of porphyrin mixtures [601,602]. The early work by Dark et al. [601] using LC-MS for coal-derived liquids was mainly concerned with the separation and identification of polycyclic aromatic components. However, it is interesting to note that... 

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. 

T. D. Perreira, N. B. Determination of Field-Ionization Relative Sensitivities for the Analysis of Coal-Derived Liquids and Their Correlation with Low-Voltage Electron-Impact Relative Sensitivities. Anal. Chem., 1976, 45 (14), 2105-2113. 

In this paper, methods to estimate the heat of formation AHj0 and the absolute entropy S° for coal and coal-derived liquids are proposed based on the group contribution method. By applying these methods and the Structured Process Energy-Exergy-flow Diagram (SPEED, 11), an exergy analysis for the H-Coal process is performed. 

Given a formula CHxOyNz of coal-derived liquid from its elemental analysis, moles of groups C-(H)n(C )4 n, Cb-(OH), and Ni-(Cb) are given as 1-fa, y, and z, respectively. Since the degree of oxygen substitution as well as of aliphatic substitution... 

The objective of this communication is to report structural information on a bituminous coal from a thorough characterization of its extracts. The characterization was carried out according to a scheme devised on the basis of our current understanding of coal chemistry. The scheme consists of considerations in preparation, fractionation, and analysis of coal-derived liquids (CDL) to obtain molecular-level information on the CDL per se as well as on the parent coal. The information obtained relates mostly to the structure of component clusters. 

The newly developed 600 MHz NMR Spectrometer is used to characterize coal-derived liquids and their chromatographically separated fractions. The distinct and well resolved proton resonance lines in both aromatic and aliphatic regions and IR analysis have been used to identify the major compounds and compound types. Double resonance technique has been applied for the chemical shift identification of donor protons (or-CHg, p-CH,) of partially hydrogenated polynuclear aromatic compounds. An NMR difference technique is applied to determine specific compositional changes in upgraded liquids derived under identical process conditions, but from different coal sources. 

The extracts were fractionated by a Preparative Liquid Chromatography method - PLC-8 [2], in eight distinct chemical classes FI-saturated hydrocarbons (HC), F2-monoaromatics, F3-diaromatics, F4-triaromatics, F5-polynuclear aromatics, F6-resins, F7-asphaltenes and F8-asphaltols. This method, proposed by Karam et al. as an extension of SARA method [4], was especially developed for coal-derived liquids. It combines solubility and chromatographic fractionation, affording discrete, well-defined classes of compounds which are readable for direct chromatographic and spectroscopic analysis. 

Separation Techniques. The complexity of the organic composition of coal-derived liquids, shale oil, and their related effluents presents a formidable challenge to the analytical chemist. Our approach to this problem has been the classical separation technique based on acid-base-neutral polarity of the organic compounds. We further subdivide the neutral fraction into aromatic and non-aromatic fractions using dimethyl-sulfoxide (DMSO) extraction. DMSO effectively removes multiringed aromatic compounds with great eflBciency (85-95%) for these complex mixtures and thus allows a straightforward analysis for polynuclear... 

Selucky, M. L. (1983) Quantitative analysis of coal-derived liquids by thin-layer chromatography with flame ionization detection. Analytical Chemistry, 5S, 141-3. 

Coal-derived liquids, heavy petroleum fractions, vegetable oils and polymers are mixtures that have very large numbers of components. It is practically impossible to identify each component by ordinary chemical analysis. One can no longer use mole fractions of individual components. Traditionally, the pseudo-component approach, or the key component approach, has been used to handle such complex mixtures. 

Applications. The methods summarized above are applicable to coal, petroleum, and shale-derived liquids. Experience acquired during the last 10-15 years shows that they yield reliable information, although obviously there are more difficulties in the analysis of heteroaromatics than in the analysis of aromatic hydrocarbons. 

Gardner et al. reported that H2S catalytic partial oxidation technology with an AC catalyst is a promising method for the removal of H2S from fuel cell hydrocarbon feedstocks.206 Three different fuel cell feedstocks were considered for analysis sour natural gas, sour effluent from a liquid middle distillate fuel processor, and a Texaco 02-blown coal-derived synthesis gas. Their experimental results indicate that H2S concentration can be removed down to the part per million level in these plants. Additionally, a power-law rate expression was developed and reaction kinetics compared with prior literature. The activation energy for this reaction was determined to be 34.4 kJ/g mol with the reaction being first order in H2S and 0.3 order in 02. 

The analytical methods used to quantify creosote and related mixtures in biological and environmental samples are summarized below. As noted in Chapter 4, coal-derived mixtures (creosote, pitch, tar) are chemically very similar the methods used for their analysis are directed to the primary components of these mixtures. In most cases uncovered through a search of the recent literature, the methods used for coal-derived mixtures are based on analysis of high-pressure liquid chromatography (HPLC) with ultraviolet (UV) absorbance detection to nondestructively separate these compounds for collection and characterization. 

Despite its smaller size and lower production, the 9 F-T plants contributed 455,000-576,000 metric tons of coal-derived oil per year during the war years 12-15 percent of Germany s total liquid fuel requirement. The historical analysis that follows examines the T-T s invention and industrial development during several decades of German social, political, and economic unrest and complements the historical literature on Germany s coal hydrogenation process. The... 

Coal liquids need to be refined to finished products such as jet fuels and diesel by hydrotreating and hydrocracking. Before GC-MS analysis of coal-derived JP-8 fuels, these fuels were first tested by separation into five distillate fractions using a fractional distillation apparatus. Table 32.9 lists the yields and boiling range of fractional distillation [33]. 

Lai, W.-C. and Song, C. Temperature-Programmed Retention Indices for GC and GC-MS Analysis of Coal- and Petroleum-derived Liquid Fuels. Fuel, 1995,74 (10), 1436-1451. Edwards, T., System Drivers for High Heat Sink Fuels. Am. Chem. Soc. Div. Petrol. 

Using microbore LC columns, a separation method was developed for a series of weakly basic cyclic and noncyclic secondary amines, which were identified as components of coal-derived solvents. As shown in another study, using normal HPLC on silica gel with Freon-113 elution, model mixtures of aliphatic and aromatic hydrocarbons and nonpolar constituents can be separated in coal-liquefaction process solvents. Encouraging results were obtained on both semipreparative (4.6 mm i.d.) and microbore (1 mm i.d.) columns. According to further reports, carbamate pesticides, polymer additives and solvent-refined coal were analysed, and the components of bergamot oil can be identified. GPC/FT-IR can be used to detect components of cold-rolling oil and to analyse polymers, whereas SEC/FT-IR can be applied to the analysis of coal liquids and to improve detection and identification of proteins. 

The quantitative estimation of species by SEC-GC-MS technique requires a mathematical solution. Two types of approaches for the quantitative estimation can be envisioned. One for the estimation of one or more selected species of interest. The second approach is based on grouping of various species in coal liquids into a few chemical lumps and estimating the quantity of these lumps by using the data derived from the analysis is technique. 

Samples Preparation. The coal liquids were derived from the catalytic liquefaction of Pittsburgh Seam bituminous and Wyoming sub-bituminous coals. The analysis of these coals is given in Table I. The coals were liquefied in a bench-scale catalytic unit using cyclone overhead product as recycle solvent to insure that the liquid products were derived from the coal and not the solvent. The product streams from... 

Mineral matter was a Deis ter table concentrate from Robena mine coal. It contained 68% pyrite and less than 4% organic material. The remainder was largely clay. In one case, a handpicked sample taken from a pyrite nodule found in a Pittsburgh seam coal was used. The microcrystals were crushed and sieved to 325 x 400 mesh. X-ray diffraction analysis indicated the only major component was pyrite, with a trace of marcasite also present. After heating in tetralin at 450°C for 15 min., the X-ray diffraction patterns of the recovered microcrystals indicated conversion was complete to pyrrhotite 1C. The coal was hvB, Homestead Mine, Kentucky, ground to pass 200 mesh. Ash and pyrite contents were 16.8% and 4.9%, respectively. The asphaltene was a homogenized mixture of samples isolated from liquid products derived from Pittsburgh seam, hvA coal. Its ash content was <0.1%( ). 

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