China
Africa
Explore chapters and articles related to this topic
Petroleum Geochemical Survey
Published in Muhammad Abdul Quddus, Petroleum Science and Technology, 2021
Coal consists of three types of distinct microscopic organic units called macerals along with inorganic materials. ‘Maceral’ particles are building blocks of coal similar to ‘mineral’ particles in rock. The difference in optical properties of the three maceral groups is utilized for their identification in kerogen and coal. The three organic maceral groups of coal which are also found in kerogen are as follows. Liptinite macerals are an amorphous component of coal/kerogen derived from waxy, resinous and algal organisms and represent types I and II kerogen. Their vitrinite reflection is the lowest among the three types of macerals.Vitrinite macerals of coal and kerogen originate from the deoxygenated macromolecular organic compounds derived from cellular woody plants. They are equivalent to type III kerogen.Inertinite macerals in the coal/kerogen are formed from highly degraded and reworked plant residue deposits. The macerals are found in type IV kerogen. The vitrinite reflectance of the group is the highest.
The Role Of Kerogen In The Sorption Of Hydrophobic Organic Chemicals By A Sandy Aquifer Material
Published in Nada Assaf-Anid, Hazardous and Industrial Wastes Proceedings of the Thirty-Third Mid-Atlantic Industrial and Hazardous Waste Conference, 2001
Examinations under fluorescence and optical microscopes show that the isolated NOM is highly heterogeneous at the particle scale. The organic particles are irregularly shaped and have sizes ranging from sub-micron to about 40 μm. Both vitrinite and bituminite or liptinite are the dominant macerals, and fusinite is a minor component found in the isolated NOM. Vitrinite is likely originated from plant materials and is the major component of Kerogen Type III. Liptinite or bituminite is commonly derived from animal’s tissues or lower level plants such as algae and is the major component of Kerogen Type I and II. Fusinite, also called black carbon or charcoal, is typically formed during incomplete oxidation of Kerogen Types I∼III and is classified as Kerogen Type IV. Vitrinite found in the isolate is opaque under transmitted microscopy, not fluorescent and is dark-grey and dark colored under fluorescence microscopy. Liptinites are found semi-transparent under optical microscopy and are yellowish green to yellow and brownish colored and manifest amorphous character under fluorescence microscopy. The reflectance (Ro) measured for vitrinite and bituminite are about 0.66 ∼ 0.82 % and 0.1 ∼ 0.23%, respectively, indicating relatively low maturation of the isolated kerogen material. Fusinite and semifusinite are opaque (transmitted), have much higher reflectance (reflected), are not fluorescent (fluorescence).
Comparative thermal behavior, Rock-Eval signature and kinetics of distinct thermally mature vitrain, fusain lithotypes and coals from India
Published in International Journal of Coal Preparation and Utilization, 2023
Bodhisatwa Hazra, David A. Wood, Prasenjeet Chakraborty, Deependra Pratap Singh, Santi Gopal Sahu, Pinaki Sarkar
The vitrinite reflectance (Ro %) measurements of the bulk coal samples from the two basins also reveal their contrasting thermal maturities. The Mvb coal sample from the Jharia basin has an Ro value of 1.07%, whereas the HvbA coal sample from the Raniganj basin has an Ro value of 0.56%. Corroborating the inferences from the Rock-Eval results, the HvbA bulk coal show higher maceral concentration of liptinite (type II kerogen; 22 vol. % measured on a mineral matter free (mmf) basis), vitrinite (type III kerogen; 48 vol. %, mmf basis), and inertinite (type IV kerogen; 30 vol. %, mmf basis). In contrast, the Mvb bulk coal sample is dominated by vitrinite (61 vol. %, mmf basis) and inertinite (39 vol. %, mmf basis), with no liptinite. Figure 4 shows the photomicrographs of the samples imaged using Carl Zeiss A×10 device at CSIR-CIMFR Dhanbad. Figures 4a,b shows the HvbA bulk coal sample imaged at the same position under reflected white light and fluorescence, respectively. Figure 4c reveals the presence of large quantities of liptinite macerals in the HvbA bulk coal sample. Figures 4d–f display the Mvb bulk coal sample under reflected white light, showing higher reflectance of the vitrinite fragments compared to those in HvbA bulk coal sample (Fig. 4a).
Multi-elemental analysis of Indian coals and its gravity fraction based on ICP-OES
Published in International Journal of Coal Preparation and Utilization, 2022
Priyanka Kumari Ujala, K.M.P. Singh, Reginald Ebhin Masto, T. Gouricharan
Carbon content in the coal samples varied from 32.02 to 53.97%. The high concentrations of carbon are normally characteristic of vitrinite rich materials. The carbon content in coal increases steadily with the increasing in coal rank. The hydrogen content was found in the range between 2.42 and 3.35%. The higher hydrogen content was usually more characteristic for lower-rank/immature coals, while reduced values tend to be more typical for higher rank coals. The concentrations of hydrogen increase with the increase in the degree of liptinite, alginate, resin, sporinite, cutinite and bituminization, as well as residual moisture, hydrated minerals and methane in coals (Cheepurupalli and Anuradha 2019; Vassilev, Kitano, and Vassileva 1997). The nitrogen content in the samples varied from 0.7 to 1.29% while sulfur in the samples content are <0.4%. The reduced values of these elements were more typical for higher order coals, while the higher sulfur content is more characteristic of lignite. The oxygen content in the samples was between 6.37 to 20.59%. The higher oxygen content was characteristic of low-rank coals, while the lower concentration is typical for higher-rank coals. In general coal with increase in gravity, the combustibles matter decreases and non-combustibles matter increases. The different density fractions of the samples were generated by laboratory float-sink method to study the nature of association and distribution of combustibles organic coaly and non-combustibles inorganic mineral matter.
Shale-gas potential from Cretaceous succession in South Africa’s Orange Basin: Insights from integrated geochemical evaluations
Published in Marine Georesources & Geotechnology, 2022
Nura Abdulmumini Yelwa, Khairul Azlan Mustapha, Mimonitu Opuwari, Mohammed Hail Hakimi
The vitrinite maceral is mostly brittle with an angular surface and diverse forms, according to optical properties using white light reflected. As a result, the matrix looks greyish and moderately portrayed in various forms (Figure 3(A(a, c, e, and g)). In addition, UV-light excitation was mainly used to distinguish between liptinite assemblages and shows that the liptinites appear low reflectance under normal white light and intensifying structural attributes among the few that fluorescence. The minor liptinitic maceral that faintly fluoresces includes resinite, cutinite, and sporinite in decreasing abundance and are characterized by fluorescence intensities ranging from greenish to yellow (Figure 3(A(b, d, f, and h)). However, the substantial vitrinitic maceral is followed by inertinite and discrete liptinite materials exhibiting kerogen of Type III (Mustapha and Abdullah 2013).