George R. Hill

The Characteristics of a Low Temperature In Situ Shale Oil

A 40

Characterization and classification of Rocky Mountain coals by Curie-point pyrolysis mass spectrometry

API crude shale oil has been produced from the Green River Formation in the Piceance Creek basin of Colorado by injection of hot natural gas at a controlled temperature. The quality of the shale oil differs very markedly from the customary shale oil from the same formation produced in a high temperature retort. The characteristics of the oil fractions have now been determined. These included distillation analyses, viscosity, and pour point determination. Kinetic data on the production of the shale oil under the conditions used in the field, but carried out on a small scale in the laboratory are presented. A possible mechanism for the production of this oil, as well as a mechanism for the production of shale oil by more usual high temperature methods is presented.

Characterization of phenols and indanols in coal-derived liquids: Use of Curie-point vaporization gas chromato-graphy/mass spectrometry

A set of 102 coal samples from the Rocky Mountain coal province, selected from the Penn State Coal Sample Bank, was analysed by Curie-point pyrolysis mass spectrometry in combination with computerized pattern recognition techniques. The spectra obtained were shown to be quite representative for the coal seams with characteristic differences often present between different seams, fields or regions within the Rocky Mountain Coal province. In general, the spectra were found to be dominated by homologous ion series, e.g., representing dihydroxybenzenes, phenols, naphthalenes, benzenes, alkenes, dienes, alkyl fragments and sulphur compounds with varying degrees of alkyl substitution. The relative abundances of dihydroxybenzenes and naphthalenes were shown to correlate closely with differences in rank, whereas those of phenols, aliphatic hydrocarbons and sulphur compounds appeared to correlate more closely with differences in depositional environment. Different spectra -dominated by aliphatic compound series -were obtained from several samples of a boghead coal (Cannel King seam). Moreover, spectra of two of these boghead coal samples, known to be severely weathered, showed markedly increased CO2+ and C6H6+ signals, indicating the presence of benzenecarboxylic acids. Factor analysis of pyrolysis m.s. data revealed the two main underlying chemical tendencies to be a shift from heteroatomic compounds to hydrocarbon series with increasing rank and a difference in degree of aromaticity corresponding primarily to differences in depositional environment. The dominant rank-related factor exhibited a clear coalification break between the ASTM hvC bituminous and hvB bituminous ranks and appears to represent a significant shift in coalification mechanisms. It was demonstrated that rank-dependent differences in the pyrolysis mass spectra enable correct classification of the spectra into four ASTM rank classes (subbituminous, hvC, hvB and hvA bituminous) in 90% of all cases. Moreover, the discovery of a marked aliphaticity/aromaticity factor in the data could be useful for the direct measurement of aromaticity (fa) from pyrolysis mass spectra of whole coals.

Characterization of U.S. lignites by pyrolysis mass spectrometry and multivariate analysis

A combination of liquid chromatography, gas chromatography and mass spectrometry techniques was used to characterize (alkyl)hydroxyaromatic compounds in several coal liquefaction process fractions, including Exxon Donor Solvent (EDS) atmospheric bottoms and hydrotreated atmospheric bottoms. Solvent extraction failed to provide representative subfractions independent of overall sample composition. Satisfactory subfractionation was achieved by liquid chromatography with increasingly polar solvents on a silica gel column. Subfractions as well as parent samples were analysed by g.c.-m.s. using a Curie-point flash vaporization technique for splitless injection onto glass SCOT columns. C0-C6 alkylphenols and C0-C3 alkylindanols were almost completely recovered in the benzene/ether subfractions and were found to be the dominant hydroxyaromatic series in both liquids. Whereas phenol distributions were virtually identical in both samples, indanol distributions differed markedly, indicating strong differences in reactivity towards hydrotreatment. The possible role and origin of indanols, the only major class of hydroxyhydroaromatic compounds in these coal-derived liquids, is discussed.

Rate data of tar hydrocracking

Abstract Sixteen Texas (Gulf Province) lignite samples and six Montana and Wyoming (Northern Great Plains Province) lignitic coals were obtained from the Pennsylvania State University Coal Bank and analyzed in triplicate by pyrolysis mass spectrometry (Py-MS) using Curie-point pyrolysis (equilibrium temp. 610°C) in combination with low-voltage (12 eV) electron ionization. The spectra obtained were evaluated by means of factor analysis, followed by discriminant analysis using only factors with eigenvalue ⩾ 1 and regarding each set of triplicate spectra as a separate category. The discriminant analysis results showed a definite separation between lignites from the two provinces as well as some clustering of samples from the same seam field or region. Six additional lignite samples obtained from an independent source and representing other regions of the Gulf Province were found to cluster with the Texas lignite samples when treated as “unknowns” in the discriminant analysis procedure. Chemical interpretation of the spectral differences underlying the clustering behavior of the lignite samples in the discriminant analysis procedure was attempted using a newly developed, unsupervised numerical extraction method for chemical components in complex spectra. This procedure, the Variance Diagram (VARDIA) technique, revealed the presence of six major chemical component axes. Examination of the spectral patterns corresponding to these component axes showed a softwood lignin-like component (high in Northern Great Plains lignitic coals) and an alipathic (algal?) hydrocarbon component (high in Gulf lignites) to be primarily responsible for the differences between the two provinces. In addition, two biomarker patterns, namely a terpenoid resin-like component and an unknown component, were shown to be highly characteristic for the Northern Great Plains and Gulf Province samples, respectively. Two other component axes were found to consist largely of sulfur-containing ion series, one of which appeared to represent an obvious marine influence on the South Texas region of the Gulf Province. Furthermore, a set of seventeen conventional coal parameters, including petrographic, ultimate and proximate analysis data as well as sulfur content, calorific value and vitrinite reflectance, obtained from the Pennsylvania State University coal data bank on all twenty-two samples, was also submitted to factor analysis. Comparison of the scores of the first two factors from this set with the scores of the first two discriminant functions of the Py-MS data set revealed an overall similarity in clustering behavior of the samples from the two provinces. Subsequently, canomical variate analysis was used to rotate both the conventional and Py-MS data sets to a common set of vectors describing the correlating (“overlapping”) portions of both data sets. Examination of the first two pairs of canonical variate functions revealed strong correlations between the conventional data and the Py-MS data, e.g., with regard to alipathic vs. aromatic or hydrocarbon vs. heteroatomic tendencies, as well as sulfur containing moieties. This enabled a final, tentative synthesis of all the data into several highly simplified schemes relating compositional aspects to depositional environments.

Activated extraction of coal using a hydrogen-donor solvent

Abstract The rate data of the hydrocracking reaction of low-temperature tar are presented. The overall order of the reaction was found to be second order below 1500 psi and first at and above 1500 psi ∗ . The rate of gasoline formation from tar was found to be represented by k1g = 0.14 k1N.O + 0.16 k1S + 0.14 k1O + 0.12 k1N + 0.08 where k1N.O′k1S′k1O′ and k1N are first order rate constants for the hydrocracking of hydrocarbons, and sulphur, oxygen and nitrogen compounds present in tar respectively.

Effects of low temperature air oxidation (weathering) reactions on the pyrolysis mass spectra of US coals

Abstract The kinetics of the extraction of a high-volatile bituminous coal with 1,2,3,4-tetrahydronaphthalene (tetralin) under the influence of ultrasonic energy has been studied at five temperatures: from 47 to 87°C. The effects of intensity of ultrasonic energy, particle size, and hydrogen content of the coal were also recorded. Analysis of the results showed that a second-order reaction followed by a first-order reaction best describes the kinetics of the extraction process. The enthalpies of the second-order and first-order regions were respectively 8.7 and 2.5 kcal/mol, suggesting essentially physical control. The entropies were respectively −44 and −70 e.u. Auxiliary experiments and the kinetic data obtained suggest a model for the extraction process. The mechanism of the overall reaction is undoubtedly complex, but the data indicate that van der Waals and hydrogen-bonding forces are most affected by the ultrasonic energy, although stronger bonding is also affected giving much higher yields than would be expected. From the yields obtained in this study it is concluded that ultrasonic energy acts by rupturing bonds that are not affected by the solvent alone; the bonds affected are either strong hydrogen bonds or aliphatic covalent bonds, but not aromatic bonds.

Conference summation and future directions

Abstract Two high volatile bituminous coals (Upper Freeport and Hiawatha seams), a subbituminous coal (Adaville seam) and a lignite (Anderson seam) were used to investigate the effect of low temperature air oxidation (‘weathering’) on the yield and composition of vacuum pyrolysis products. Fresh coal samples were exposed to air at 80 and 100°C for up to 10 days under controlled laboratory conditions. Curie-point pyrolysis mass spectrometry combined with computerized data analysis was applied to study the weathering induced changes in a series of samples weathered for various lengths of time. It was found that the abundance of small oxygen-containing molecules such as carbon monoxide, carbon dioxide and aliphatic carboxylic acids increased in the pyrolysate of all samples, whereas phenols and dihydroxybenzenes showed decreased yields, especially in the two lowest rank coals. Besides phenols, alkylnaphthalenes and alkyltetralins showed decreased abundances in the pyrolysis mass spectra of the two high volatile bituminous coals. An attempt is made to explain the difference in pyrolysis patterns observed before and after weathering experiments in terms of underlying structural changes.

Kinetic relationship of coal hydrogenation, pyrolysis and dissolution

Rapport de synthese des communications presentees a la Conference sur la Science du Charbon tenue a Pittsburgh en aout 1983