Sample records for exinite

  1. EPR evidence for thermally excited triplet states in exinite, vitrinite and inertinite separated from bituminous coal

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    Slowik, G.P.; Wojtowicz, W.; Wieckowski, A.B. [University of Zielona Gora, Zielona Gora (Poland). Inst. of Physics


    In this work we have made an electron spin resonance (EPR) study of macerals obtained from the lithotype clarain separated from Polish medium-rank coal (85.6 wt.% C). For three macerals (exinite, vitrinite, and inertinite), the temperature dependence of intensity of EPR spectra in the temperature range of 100-373 K was investigated. The experimentally obtained EPR spectra of macerals were fitted by curves of the derivatives of the Gaussian and Lorentzian functions. The best fitting was obtained, when the experimental EPR spectra were assumed to be a superposition of three lines, for exinite and vitrinite - a broad Gaussian (G), a broad Lorentzian (L1) and a narrow Lorentzian (L3) line, but for inertinite of two lines - a narrow Lorentzian (L2) and a narrow Lorentzian (L3) line. The computer-assisted fitting has shown that each individual component line has similar values of resonance field, but different linewidths and amplitudes. The temperature dependence of line intensity I of the broad Gaussian (G) and narrow Lorentzian (L2 and L3) lines fulfils the Curie law in the form I = C/T or IT = C, whereas the broad Lorentzian (L1) line does not fulfil the Curie law. In the last case the temperature dependence of the Lorentzian (L1) component was fitted by the relation I = C/T + B/(T(3 + exp(J/kT))) or IT C + B/(3 + exp(J/kT))), valid for thermally excited triplet states (S = 1). For exinite and vitrinite the curves presenting the temperature dependence of the product IT versus temperature T were resolved into two curves, one for paramagnetic centres in the doublet state (S = ), and the other for paramagnetic centres in the thermally excited triplet state (S = 1).

  2. Reactions of oxygen containing structures in coal pyrolysis

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    Hodek, W.; Kirschstein, J.; Van Heek, K.-H. (DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany, F.R.))


    In coal pyrolysis O-containing structures such as ether bridges and phenolic groups play an important role. Their reactions were studied by non-isothermal pyrolysis of a high volatile bituminous coal and some model polymers with gas chromatographic detection of the gaseous pyrolysis products. The coal was separated into the maceral groups vitrinite, exinite and inertinite, which showed markedly different pyrolysis behaviour. The formation of CO, methane and benzene was measured versus temperature. By comparison with polyphenyleneoxide and phenol-formaldehyde resins, it was found that the main volatilization, during which most of the tar is evolved, is initiated by cleavage of alkyl-aryl-ethers. Rearrangements of the primarily formed radicals lead to the formation of CO and methane at higher temperatures. 5 refs., 8 figs., 1 tab.

  3. Analysis of the relationship between the coal properties and their liquefaction characteristics by using the coal data base; Tanshu data base ni yoru tanshitsu to ekika tokusei no kaiseki

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    Kanbayashi, Y.; Okada, K. [Coal Mining Research Center, Tokyo (Japan)


    The relationship between coal properties and liquefaction or gasification characteristics was analyzed by using the analysis and test results and liquefaction characteristics in the coal data base. On liquefaction reaction, the close relation between an oil yield and coal constituent composition or a coal rank is well-known. Various multivariable regression analyses were conducted by using 6 factors as variables such as calorific value, volatile component, O/C and H/C atomic ratios, exinite+vitrinite content and vitrinite reflectance, and liquefaction characteristics as variate. On liquefaction characteristics, the oil yield of dehydrated and deashed coals, asphaltene yield, hydrogen consumption, produced water and gas quantities, and oil+asphaltene yield were predicted. The theoretical gasification efficiency of each specimen was calculated to evaluate the liquefaction reaction obtained. As a result, the oil yield increased with H/C atomic ratio, while the theoretical gasification efficiency increased with O/C atomic ratio. 5 figs., 1 tab.

  4. Preliminary investigation of predictors of the cutting forces for some South African coals

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    MacGregor, I M; Baker, D R


    This paper discusses the possible use of petrological data and proximate analyses in the prediction of cutting forces for coal. It is restricted to the development of univariate predictors based on data from thirteen collieries in five major Transvaal and Orange Free State coalfields and three coal provinces. The aim of the work was the identification and development of the best predictors of mean peak cutting force and Hardgrove grindability index from among the independent variables evaluated. The data were processed according to the SPSS computer package. The analysis revealed reasonable correlations between the Hardgrove grindability index and (1) the volatiles and vitrinite content in the Vereeniging-Sasolburg and South Rand Coalfields, (2) the contents of vitrinite, vitrinite plus exinite, and minerals plus inertinite in the Eastern Transvaal Coalfield.

  5. Trace elemental analysis of bituminous coals using the Heidelberg proton microprobe

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    Chen, J R; Kneis, H; Martin, B; Nobiling, R; Traxel, K [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany, F.R.); Heidelberg Univ. (Germany, F.R.). Physikalisches Inst.); Chao, E C.T.; Minkin, J A [Geological Survey, Reston, VA (USA)


    Trace elements in coal can occur as components of either the organic constituents (macerals) or the inorganic constituents (minerals). Studies of the concentrations and distribution of the trace elements are vital to understanding the geochemical milieu in which the coal was formed and in evaluating the attempts to recover rare but technologically valuable metals. In addition, information on the trace element concentrations is important in predicting the environmental impact of burning particular coals, as many countries move toward greater utilization of coal reserves for energy production. Traditionally, the optical and the electron microscopes and more recently the electron microprobe have been used in studying the components of coal. The proton-induced X-ray emission (PIXE) microprobe offers a new complementary approach with an order of magnitude or more better minimum detection limit. We present the first measurements with a PIXE microprobe of the trace element concentrations of bituminous coal samples. Elemental analyses of the coal macerals-vitrinite, exinite, and inertinite - are discussed for three coal samples from the Eastern U.S.A., three samples from the Western U.S.A., and one sample from the Peoples Republic of China.

  6. Berau coal in East Kalimantan; Its petrographics characteristics and depositional environment

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    Nana Suwarna


    Full Text Available asses the characteristics of the Early to Middle Miocene Berau coal in the Berau Basin, leading to interpretation of coal depositional environments, some fresh outcrop and subcrop samples and also drill cores of the coals have been analyzed microscopically. Coal petrographic analysis was performed on twenty four coal samples from the Middle Miocene Lati Formation. Vitrinite, present in a high value, and ranging between 66.2 - 96.2%, is dominated by vitrinite B. On the other hand, inertinite and exinite, showing a similar value, exist in a low to moderate amount. Vitrinite reflectance, present in a low value, varies from 0.40 - 0.58%. Low mineral matter content is dominated by clay minerals (0.4 - 6.6% with minor pyrite. Transitions from wet and very wet forested swamps to drier conditions with lower tree density are indicated by the higher content of vitrinite B, whilst a reverse trend is indicated by the lower content of vitrinite A. Petrographic indices obtained from facies diagnostic macerals show that an accumulation of the ancient peats under prevailing relatively wet limited influx clastic marsh to very wet forest swamps or moors is considered. The composition of the coal samples supports the interpretation of a system of fluvial to meandering streams in an upper delta plain environment. The original peat-forming vegetation was composed mainly of cellulose rich, shrub-like plants, tree ferns, herbaceous plant communities, with minor amount of trees. Thereby, the organic facies concept is thus applicable in basin studies context and has potential to become an additional tool for depositional environment interpretation.  

  7. Petrography and rank of the Bhangtar coals, southeastern Bhutan

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    Pareek, H S [BH23, Meerut (India)


    In Bhutan, a potential coal deposit is exposed at Bhangtar in the 'landslide zone'. Nineteen coal seams are encountered in this area, and occur in the Lower Gondwana Supergroup preserved in between the Main Boundary Fault and the Thrust. The coal is low in moisture, {lt}1.76%, but the coal cores show moisture values of 3.16%. The ash content is up to 48.87% and increases substantially in the younger seams. The volatile content (on a pure coal basis) ranges from 23.38% to 41.02%. The sulphur content is less than 0.61%. The coals are non-coking. The amount of trace elements in the coal is quite low. The average petrographic composition of the Bhangtar coal is vitrinite - 31%, exinite - 2%, inertinite - 31%, and mineral and shaly matter - 36%, the vitrinite proportion decreases from the older to the younger seams, which are shaly. an age can be assigned to the Bhangtar coal. Based on oil reflectance, the rank of the coal is metalignitous to hypobituminous. The average microlithotype composition of the coal is vitrite - 30%, clarite - 1%, vitrinertite V - 14%, vitrinertite I - 11%, durite - 3%, fusite - 14%, and carbominerite - 27%. Vitrite decreases in proportion towards the younger seams, 'intermediates' show a concomitant increase, while durite and fusite remain constant. Carbonaceous shale contains fragmentary inertinite and vitrinite macerals and is interlayered with micro-bands of shaly coal which is characterised by abundant fragments of fusinite and vitrinite. The coal is very fragile and thus amenable to economic beneficiation. The coal is used as fuel in electric power plants. The Bhangtar coal is characteristically distinct from the Gondwana coals of India in petrography and rank, but correlates petrographically with the Kameng coals of Arunachal Pradesh, India. 18 refs., 4 figs., 8 tabs., 3 plates.

  8. Mass spectrometric and chemometric studies of thermoplastic properties of coals. 1. Chemometry of conventional, solvent swelling and extraction data of coals

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    Marzec, A.; Czajkowska, S.; Moszynski, J.; Schulten, H.-R. (Polish Academy of Sciences, Gliwice (Poland). Inst. of Coal Chemistry)

    Twenty-seven coals from Carboniferous seams in Poland were studied with the aim to find links between thermoplastic properties and chemical characteristics of the coals. Three sets of data were obtained for all the coals: (1) thermoplastic properties measured using the Gieseler plastometer; (2) yields of pyridine extractables and swelling measurements for pyridine residues; (3) ultimate, proximate, and petrographic analyses. The three data sets were evaluated using chemometric techniques with the purpose of looking for significant correlations between all the data. Temperature of softening is a linear regression of pyridine extractables and hydrogen content in coals as well as of swelling data. Temperatures of maximum fluidity and resolidification are correlated with each other and with oxygen, exinite, and moisture contents of the coals as well as with the swelling data. It has been concluded that temperature of softening is a colligative property and indicates a phase transition resulting in an increase of thermal induced mobility of coal material; the energy demand of the transition is dependent on contents of bulk components of coal system that were specified in this study. Temperatures of maximum fluidity and resolidification appear to have the same chemical background; i.e. the temperatures depend on the content of the same structural units or components. However, the means of chemical characterization of coal material used in this study were not capable of identifying them. Volatile matter and petrographic composition showed rather limited value as predictive means for some (T{sub F(max)} and T{sub R}) and no predictive value for the other thermoplastic properties. 20 refs., 1 fig., 5 tabs.

  9. Eo-Oligocene Oil Shales of the Talawi, Lubuktaruk, and Kiliranjao Areas, West Sumatra: Are they potential source rocks?

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    M. Iqbal


    Full Text Available DOI:10.17014/ijog.v1i3.198To anticipate the increasing energy demand, additional data and information covering unconventional fossil fuels such as oil shale must be acquired to promote the usage of alternative energy sources to crude oil. The Talawi and Lubuktaruk regions situated within intra-montane Ombilin Basin, and the Kiliranjao assumed to be a small intra montane basin are occupied by Eo-Oligocene sediments of Sangkarewang and Kiliran Formations, respectively. Field activity, geochemical screening techniques, and organic petrographic analysis, supported by SEM mode, are methods used. Most of the oil shale sequence is typically of an organically rich-succession comprising predominantly well-bedded, laminated and fissile, brownish to dark grey organic-rich shale and mudstone rocks. The exinite macerals within oil shale comprise mainly Pediastrum-lamalginite with minor cutinite, resinite, liptodetrinite, sporinite, bituminite, and rare Botryococcus-telalginite. Therefore; the oil shale deposits can be described as “lamosites”. Minor vitrinite maceral is also recognized. TOC analysis on selected shale samples corresponds to a fair up to excellent category of source rock characterization. The hydrogen index (HI for all samples shows a range of values from 207 - 864, and pyrolysis yield (PY ranges from 2.67 to 79.72 mg HC/g rock. The kerogen is suggested to be of mixed Type II and Type I autochthonous materials such as alginite, with minor allochthonous substances. Oil samples collected appear to be positioned within more oil prone rather than gas prone. Thermal maturity of the oil shales gained from Tmax value and production index (PI tends to show immature to marginally/early mature stage. A consistency in the thermal maturity level results by using both Tmax and vitrinite reflectance value is recognized. On the basis of  SEM analysis, the oil shale has undergone a late eodiagenetic process. Thereby, overall, vitrinite reflectance

  10. Application of automated image analysis to coal petrography (United States)

    Chao, E.C.T.; Minkin, J.A.; Thompson, C.L.


    The coal petrologist seeks to determine the petrographic characteristics of organic and inorganic coal constituents and their lateral and vertical variations within a single coal bed or different coal beds of a particular coal field. Definitive descriptions of coal characteristics and coal facies provide the basis for interpretation of depositional environments, diagenetic changes, and burial history and determination of the degree of coalification or metamorphism. Numerous coal core or columnar samples must be studied in detail in order to adequately describe and define coal microlithotypes, lithotypes, and lithologic facies and their variations. The large amount of petrographic information required can be obtained rapidly and quantitatively by use of an automated image-analysis system (AIAS). An AIAS can be used to generate quantitative megascopic and microscopic modal analyses for the lithologic units of an entire columnar section of a coal bed. In our scheme for megascopic analysis, distinctive bands 2 mm or more thick are first demarcated by visual inspection. These bands consist of either nearly pure microlithotypes or lithotypes such as vitrite/vitrain or fusite/fusain, or assemblages of microlithotypes. Megascopic analysis with the aid of the AIAS is next performed to determine volume percentages of vitrite, inertite, minerals, and microlithotype mixtures in bands 0.5 to 2 mm thick. The microlithotype mixtures are analyzed microscopically by use of the AIAS to determine their modal composition in terms of maceral and optically observable mineral components. Megascopic and microscopic data are combined to describe the coal unit quantitatively in terms of (V) for vitrite, (E) for liptite, (I) for inertite or fusite, (M) for mineral components other than iron sulfide, (S) for iron sulfide, and (VEIM) for the composition of the mixed phases (Xi) i = 1,2, etc. in terms of the maceral groups vitrinite V, exinite E, inertinite I, and optically observable mineral

  11. Recommended procedures and techniques for the petrographic description of bituminous coals (United States)

    Chao, E.C.T.; Minkin, J.A.; Thompson, C.L.


    Modern coal petrology requires rapid and precise description of great numbers of coal core or bench samples in order to acquire the information required to understand and predict vertical and lateral variation of coal quality for correlation with coal-bed thickness, depositional environment, suitability for technological uses, etc. Procedures for coal description vary in accordance with the objectives of the description. To achieve our aim of acquiring the maximum amount of quantitative information within the shortest period of time, we have adopted a combined megascopic-microscopic procedure. Megascopic analysis is used to identify the distinctive lithologies present, and microscopic analysis is required only to describe representative examples of the mixed lithologies observed. This procedure greatly decreases the number of microscopic analyses needed for adequate description of a sample. For quantitative megascopic description of coal microlithotypes, microlithotype assemblages, and lithotypes, we use (V) for vitrite or vitrain, (E) for liptite, (I) for inertite or fusain, (M) for mineral layers or lenses other than iron sulfide, (S) for iron sulfide, and (X1), (X2), etc. for mixed lithologies. Microscopic description is expressed in terms of V representing the vitrinite maceral group, E the exinite group, I the inertinite group, and M mineral components. volume percentages are expressed as subscripts. Thus (V)20(V80E10I5M5)80 indicates a lithotype or assemblage of microlithotypes consisting of 20 vol. % vitrite and 80% of a mixed lithology having a modal maceral composition V80E10I5M5. This bulk composition can alternatively be recalculated and described as V84E8I4M4. To generate these quantitative data rapidly and accurately, we utilize an automated image analysis system (AIAS). Plots of VEIM data on easily constructed ternary diagrams provide readily comprehended illustrations of the range of modal composition of the lithologic units making up a given coal

  12. Coal Reservoir Physical Property Features and CBM Resource Potential in Xingtai Coal-bearing Region%邢台含煤区煤储层物性特征及煤层气资源潜力

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    高亮; 上官拴通; 张国斌; 李英英; 闫家栋


    为了评价邢台含煤区煤层气开发潜力,采集不同矿井的2、8、9号煤样进行了煤岩组分、孔裂隙分布、等温吸附及水单相渗透率实验分析,采用体积法和综合排队系数法对底板标高-2000 m以浅的煤层气资源量进行了预测和评价.结果表明:区内目的煤层厚度、煤级适中,具有较好的生储条件;煤岩的镜质组、惰质组和壳质组含量依次减少,水分随煤化程度的增加呈现先减小后增大,挥发分随煤化程度的增加而减少;孔隙度随煤化程度增大而增大,且孔径分布不均匀,微孔的孔容和比表面积所占比例最大;显微裂隙密度级别为一级,部分裂隙被脉状方解石和粒状黄铁矿充填;煤的吸附量受煤级控制,且在一定压力范围内,吸附量随压力增加而增大,吸附能力随压力增加而减小;煤层渗透率离散性较大,属中~高级渗透率.估算底板标高-2000 m以浅潜在的煤层气资源量为427.31亿m3,优选出中等有利区块6个,其中FY区、QHY区、GZ区为煤层气勘探首选区块.%To assess CBM exploitation potential in the Xingtai coal-bearing region, collected coal samples from coal seam Nos. 2, 8 and 9 in different coalmines, carried out experimental analysis of coal lithotype, pore and fissure distribution, isothermal adsorption and wa-ter single-phase permeability. Through the volumetric method and integrated queuing coefficient method carried out prediction and as-sessment of CBM resources above floor elevation-2000 m. The result has shown that the target coal thickness and coal rank are moder-ate, thus have better CBM generation and preservation conditions. Contents of coal macerals vitrinite, inertinite and exinite are sequen-tially deceasing;moisture content increasing along with coalification degree increasing presents deceasing first than increasing;volatile matter decreasing along with coalification degree increasing. Porosity is increasing along with coalification

  13. Organic petrology and Rock-Eval characteristics in selected surficial samples of the Tertiary Formation, South Sumatra Basin

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    M. H. Hermiyanto


    Full Text Available petrologic data of the DOM of Talangakar and Muaraenim Formations show that the organic matter consisting mainly of vitrinite group is essentially composed of telocollinite (1.0 – 70.8 % and desmocollinite (0.8 – 66.6 % with minor telinite (0.6 – 9.4 %, detrovitrinite (0.6 – 6.0 %, and cor- pocollinite (0.6 – 2.0 %. Minor exinite (0.4 – 7.8 % and inertinite (0.4 – 8.0 % are also determined. However, mineral matter varies from 0.6 – 99.44 %. Downwards, the increase in vitrinite reflectance (0.33 – 0.48 % is concomitant with the depth of each formation. Furthermore, based on Rock-eval pyrolysis, TOC value of the Talangakar Formation ranges from 0.09 – 15.38 %, Gumai 0.34 – 0.39 %, Airbenakat 0.32 – 4.82 %, and Muaraenim between 0.08 – 15.22 %. Moreover the PY (Potential Yield value variation of the Talangakar, Gumai, Airbenakat, and Muaraenim Formations are between 0.04 – 36.61 mg HC/g rock, 0.53 – 0.81 mg HC/g rock, 0.1 – 4.37 mg HC/g rock, and 0.07 – 129.8 mg HC/g rock respectively. Therefore, on the basis of those two parameters, the four formations are included into a gas - oil prone source rock potential. However, the Talangakar and Muaraenim Formations are poor to excellent category, whereas the Air Benakat tends to indicate a poor – fair category and Gumai Formation are only within a poor category. Tmax value of the Talangakar ranges from 237 – 4380 C, Gumai 316 – 3590 C, Airbenakat 398 – 4340 C with exceptions of 4970 C and 5180 C, and Muaraenim Forma- tions 264 – 4250 C. The Talangakar Formation contains kerogen Type II dan III, with the HI (Hydrogen Index value varies from 45.16 – 365.43. However two samples show value of 0. The organic content of the Gumai and Air Benakat Formations are included into kerogen type III, with HI value ranges from11.87 – 40.82, and 19 – 114 respectively. Moreover the Muaraenim Formation has two category of