Browsing by Author "Prakash K. Singh"

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A Preliminary Evaluation on the Prospects of Hydrocarbon Potential in the Carbonaceous Shales of Spiti and Chikkim Formations, Tethys Himalaya, India
(Geological Society of India, 2018) Bindhyachal Pandey; Deo Brat Pathak; Neeraj Mathur; Anand K. Jaitly; Alok K. Singh; Prakash K. Singh
In the present investigation, an attempt has been made to explore the possibility of hydrocarbon prospects in the carbonaceous shale deposits of Spiti and Chikkim formations exposed in the Spiti valley of the Tethys Himalaya. Twenty samples, collected from successive levels of these litho-units, have been subjected to maceral analysis, Rock-Eval Pyrolysis and six samples to Fourier Transform Infra-red Spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analyses. The study reveals the presence of mainly kerogen-III type of organic matter but some of the shale samples have shown a good amount of total organic carbon (TOC) to the tune of 3.19% which is sufficient to produce hydrocarbon. The results indicate the presence of methane occurring as free and fixed hydrocarbon in the shale samples. Few levels are especially rich in hydrocarbon. They have shown encouraging results with potential for generating liquid as well as lighter hydrocarbon. The data is also supported by the FTIR and NMR studies. © 2018, Geological Society of India.
A study on assessment of hydrocarbon potential of the lignite deposits of Saurashtra basin, Gujarat (Western India)
(Springer International Publishing, 2017) Prakash K. Singh; V.K. Singh; P.K. Rajak; Neeraj Mathur
In the present investigation, Bhavnagar lignites of the Saurashtra basin (Gujarat) have been studied to assess their hydrocarbon generating potential. The samples of upper as well as lower lignite seams have been studied through microscopy and subjected to various chemical analyses viz. proximate analysis, ultimate analysis and Rock-Eval Pyrolysis. These lignites have high moisture and low to moderate ash yield but are characterized by high volatile matter. Petrographically they comprise predominantly of huminite group maceral while liptinite and inertinite groups occur in subordinated amount. Huminite is chiefly composed of detrohuminite and telohuminite. The Tmax (av. 416.23 °C) and huminite reflectivity (0.28%–0.30%) indicate a low degree of maturity for these lignites which is also substantiated by the Tmax versus hydrogen index plot. The organic matter is subjugated by kerogen Type-III with a potential to expel hydrocarbon on liquefaction. Study further reveals that the fixed hydrocarbon is several folds higher than the free hydrocarbons. Being high in reactive maceral content, a high ‘conversion’ and good ‘oil yield’ values for these lignites were observed. Thus, the empirically derived values match well with those obtained through the experimental values of Rock-Eval Pyrolysis and validate their hydrocarbon generating potential. © 2017, The Author(s).
Application of Optical-electron Correlative Microscopy for Characterization of Organic Matter
(Geological Society of India, 2024) Bodhisatwa Hazra; Prakash K. Singh; Chinmay Sethi; Jai Krishna Pandey
Application of coal petrology is known to play significant role in several industrial sectors viz. thermal industries, steel industries, unconventional oil and gas fields. One important aspect of organic matter characterization, especially for unconventional oil and gas fields is the development of organic matter hosted porosity, and commonly Scanning Electron Microscopy (SEM) is used to study the same. While, SEM helps in understanding the nature of porosity developed in coals and shales, one significant limitation is that under SEM the different organic matter types can’t be distinguished, as all organic matter appears dark due to their lower atomic mass. Optical-electron correlative microscopy has recently gained importance for making advancement in addressing the above-mentioned scientific gap. While this method has been found some usage for characterizing the dispersed organic matter in shales, only one work globally exists where the technique has been used for studying coals. In this work, possibly, for the first time, this technique is applied for characterizing three Indian coals from Korba basin, India, with the main objective of establishing necessary protocols for reliable imaging of different organic matter types under SEM. Our results establish that imaging under SEM using Backscattered electron (BSE) detector, the macerals and mineral matter were clearly discernible at 15 kV accelerating voltage. Further, this exercise also indicates that identification of vitrinite macerals under SEM, without correlative technique can be challenging, while some inertinites with their distinctive structures can be identified under stand-alone SEM. Sporinites too, due to their distinctive morphology, were easily identifiable under SEM. © 2024 Geological Society of India, Bengaluru, India.
Applicative Coal Petrology for Industries: New Paradigms
(Springer, 2022) Prakash K. Singh
Coal petrology plays a significant role in understanding coal behaviour during various industrial processes such as carbonization, gasification and liquefaction and helps in characterizing them accordingly. Proper use of fluorescence microscopy and vitrinite reflectance measurement is crucial; carbonization study shows that maceral composition and rank affect the thermoplasticity wherein vitrinite contributes most to the coke formation. Further, the vitrinite is catalyzed by the presence of exsudatinite. Liptinite, when associated with vitrinite, lowers the viscosity of coal during coke making. Coal petrology is successfully used to assess suitability of a coal for coking to predict coke strength and to evaluate coal for coal-blend designing. Composition, structure and behaviour of coke are revealed through petrographic study. The stability and reactivity of coke can also be realised through microscopy. Gasification of coal is performed best in bituminous coal while it is expensive in case of low rank or low grade coals. It can be a simple coal gasification, fixed bed gasification, fluidized-bed gasification, entrained-flow and molten-bath coal gasification. Though any coal may be used for gasification but coal with high reactive components are more suitable but bituminous coal with high inertinite is also suitable as per few researchers. Some minerals have catalytic effect while others act as inhibitors. Elemental composition of organic and inorganic matter of coal, its surface characteristics, porosity and intrinsic reactivity have important bearing on efficiency of gasification. Coal liquefaction is a clean fuel technology which requires proper petrological characterization of coal before processing it. Rank and type of coal along with its composition influence the liquefaction behaviour. Thus, it is imperative to carry out a complete coal microscopy before coal is utilized for making coke/coke-blend or liquid and gaseous hydrocarbon. © 2022, Geological Society of India, Bengaluru, India.
Bacterial desulphurization of low-rank coal: A case study of Eocene Lignite of Western Rajasthan, India
(Taylor and Francis Inc., 2018) Alok K. Singh; Aniruddha Kumar; Prakash K. Singh; Asha Lata Singh; Alok Kumar
High sulfur lignite samples collected from Giral mine was subjected to desulfurization using bacteria Burkholderia sp. GR 8–02 isolated from native lignite. A removal of 50.69% of total Sulfur (St) has been observed. The reduction in hydrogen and ash content was found up to 2.92% and 14.78%, respectively. In addition, relative carbon (up to 12.81%) and nitrogen (up to 34.52%) has also been increased. An increase in the relative concentration of volatile matter and fixed carbon (up to 19.47% & 3.29%) has been detected. In addition, the desulfurization of high sulfur lignite with Burkholderia sp. GR 8–02 increased the calorific value from 5.24% to 20.74%. © 2018 Taylor & Francis Group, LLC.
Beneficiation of High Sulfur Tertiary Coal of Assam with Burkholderia sp. GR 8-02. An Eco-Friendly Approach Toward Clean Coal Production
(Taylor and Francis Ltd., 2024) Aniruddha Kumar; Asha Lata Singh; Pramod K. Rajak; Alok Kumar; Prakash K. Singh
The high sulfur content in North-East Indian coal is one of the primary challenges with using it as an energy source. Therefore, the present study uses Burkholderia sp. GR 8-02 to explore coal beneficiation from the Tipong mine (T20 and T60) in Assam (North-East India). Various particle size fractions (−125 to +210 µm, −210 to +250 µm, −250 to +297 µm, −297 to +400 µm and −400 to +500 µm) were treated and subjected to petrographic and chemical analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS), Thermogravimetric analysis (TGA), and Raman spectral analysis. The results revealed a 39.04% and 32.43% reduction in total sulfur for T20 and T60 samples, respectively. The ash content decreased by 19.79% in the T20 coal sample and by 24.52% in the T60 coal samples, with a relative decrease in the mineral matter content of approximately 17.43%. Following beneficiation with Burkholderia sp. GR 8-02, the −125 to +250 µm coal fraction exhibited maximum ash removal. The T20 sample useful heating value increased from 8116 to 8203 kcal/kg and the T60 sample from 8060 to 8210 kcal/kg. X-ray diffraction and FTIR patterns showed mineral phases like quartz, kaolinite, and pyrite. The FTIR spectra indicated altered C-S, SO2, and C=O bonds. The thermal profile showed a 12.54% mass loss difference between untreated and treated coal samples, suggesting lower thermal stability post-treatment without affecting the useful heating value (UHV). The treated coal’s surface leaching and morphological structure changes were investigated using Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) images. Raman analysis revealed increased carbon crystallinity and molecular structure in treated coal. This study offers an environmentally friendly and efficient approach to clean coal production. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
Characterization of lignite deposits of Barmer Basin, Rajasthan: insights from mineralogical and elemental analysis
(Springer Science and Business Media B.V., 2023) Om Prakash Kumar; P. Gopinathan; Amiya S. Naik; T. Subramani; Prakash K. Singh; Anupam Sharma; Sudip Maity; Sujan Saha
The geochemistry of fly ash produced from the combustion of coal at thermal power plants presents a significant challenge for disposal and environmental impact due to its complex mineralogical and elemental composition. The objective of this study was to investigate the mineralogical and elemental distribution of thirty lignite samples from the Barmer Basin using advanced techniques such as X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). XRD analysis revealed the presence of minerals such as haematite (Fe2O3), nepheline, anhydrite, magnesite, andalusite, spinel and anatase. Other minor minerals included albite, siderite, periclase, calcite, mayenite, hauyne, pyrite, cristobalite, quartz, nosean and kaolinite. XRF analysis demonstrated that the most abundant elements in the Barmer Basin lignite ash were iron oxide (Fe2O3), sulphur oxide (SO3), calcium oxide (CaO), and quartz (SiO2) followed by minor traces of toxic oxides (SrO, V2O5, NiO, Cr2O3, Co2O3, CuO) that are known to have adverse effects on human health and the environment. The rare earth element (REE) composition showed higher concentrations of Tb, Dy, Ho, Er, Tm, Yb, Lu, Y and Sc at the Giral and lower concentrations at Sonari mine. The Barmer lignites recorded higher concentration of trace elements such as V, Cr, Co, Ni, Cu and Sr while lower concentration of Rb, Cs, Ba, Pb, As, Th and U were observed within optimal range. The study findings revealed the predominant mineral concentration, elemental makeup, trace elements and rare earth elements associated with lignite reserves in the Barmer Basin. © 2023, The Author(s), under exclusive licence to Springer Nature B.V.
Conifer-mixed tropical rainforest in the Indian Paleogene: New evidences from terpenoid signatures
(Elsevier B.V., 2022) Rimpy Chetia; Runcie P. Mathews; Prakash K. Singh; Anupam Sharma
The Paleocene sediments from Barsingsar lignite mine section of Bikaner-Nagaur Basin in Rajasthan, India were subjected to gas chromatography–mass spectrometry (GC–MS) analysis to resolve its botanical history in relation to its terpenoid composition. The terpenoid suite was characterised by sesquiterpenoids, diterpenoids, and sporadic triterpenoids. The presence of sesquiterpenoids along with drimane, norcadalenes, cadalenes and their related compounds hint to higher plant input. High abundance of diterpenoids and their temporal universality imply a significant gymnosperm input. The diterpenoid-class of terpenoids, primarly comprises of conifer-derived abietane, phyllocladane, kaurane, pimarane/isopimarane and podocarpane-class compounds. It further point to Southern Hemisphere conifer families, Podocarpaceae and Araucariaceae. Exceptional void of phenolic abietane and labdane derivatives rule out the probability of Pinaceae as the source of these terpenes. A very low abundance of pentacyclic terpenoids like oleanane-derivatives suggest low angiosperm-derived terpenoid contribution. The average value of pristane/phytane in the realm, 1.7 indicated oxic to suboxic depositional setting. The values of ar-AGI (aromatic Angiosperm/Gymnosperm Index), t-AGI 1 and t-AGI 2 spans over 0.01 to 1, 0.009 to 1.23, and 0.002 to 0.34 respectively for the section. The research provided evidence of the occurrence of a tropical rainforest where conifers were a significant element or remained a refugia in the midst of emerging angiosperms as life stabilized in the Paleogene after the devastating Cretaceous-Paleogene (K/Pg) boundary. © 2022
Demineralization of Coal from Johilla Coalfield using Neutrophilic Native Bacteria: A Novel Technique to obtain REE from Coal
(Geological Society of India, 2024) Shweta Rai; Asha Lata Singh; Prakash K. Singh
Mineral matter in coal is the host of several environmentally sensitive elements and a potential source of Rare Earth Elements (REE). During combustion, some trace elements are liberated as gas, while others get concentrated in ash, contaminating soil and local water bodies. Minimizing the inorganic content makes the coal clean and eventually increases its calorific value. Bacteria serve as an eco-friendly remediation tool, particularly neutrophilic ones that facilitate the treatment at mild pH and ambient temperatures. Use of native bacteria accelerates the treatment process by readily adapting to substrates. We present the remediation potential of three native neutrophilic bacteria in this study. After six days of treatment, Bacillus sp. CpH06 has reduced ash yield by 15.96%, trace elements by 26% to 75%, and REE by 24% to 50%. Bacillus anthracis CpH08 has reduced ash yield by 22.6%, trace elements by 6.4% to 70.5%, and REE by 8.4% to 37%. Maximum ash yield reduction of 22.91% was attained by the Cronobacter sp. CpH10 including reduction of 8.1% to 73% of trace elements and 26% to 48% of REEs. The FTIR spectra reveal alterations in both peak intensity and position of inorganic functional groups resulting from the removal of elements, formation of new bonds, and the elimination of certain pre-existing functional groups. XRD spectra indicate bio-oxidation mechanism, exhibited by the removal of copper sulfate hydroxide and pyrite along with formation of Jarosite and metal-sulfide peaks. The findings encourage further research on the effectiveness and performance of these bacteria on diverse types of coals. © 2024 Geological Society of India, Bengaluru, India.
Demineralization of Gondwana coal with Pseudomonas mendocina strain B6-1: a case study of coal from Gopinathpur top and bottom seams of Mugma mine, Dhanbad, Jharkhand (India)
(Springer Verlag, 2016) Prakash K. Singh; Asha Lata Singh; Mahendra P. Singh; A.S. Naik; Dharmshila Singh; Spardha Rai; Aniruddha Kumar
In the present investigation an attempt has been made to demineralize the Gondwana coal of Gopinathpur top and bottom seams of Mugma mine, Raniganj coalfield, Dhanbad with the help of Pseudomonas mendocina strain B6-1. The change in the amount of ash yield and decrease in the concentration of selected minor elements like Na, K, Mn and Ca and environmentally sensitive selected trace elements such as Cd, Pb, Se, Ni, Mn, and Zn have been studied as a function of time of bacterial treatment as well as with variation in the bacterial biomass. After 28 days of bacterial treatment there was variable amount of decrease observed in ash yield as well as in the concentration of minor and trace elements. The removal of the elements was further enhanced with the increase in the bacterial biomass from 10 to 25 mg/mL. Due to over exploitation of superior grade coals in the country, the remaining coal resources, available for current use, are inferior in grade and contain high level of impurities and there is ample scope of bio-beneficiation of these coals using bacterial biomass. © 2016, The Author(s).
Demineralization of Rajmahal Gondwana coals by bacteria: Revelations from X-ray diffraction (XRD) and Fourier Transform Infra Red (FTIR) studies
(Multi-Science Publishing Co. Ltd, 2015) Asha Lata Singh; Prakash K. Singh; Aniruddha Kumar; Mahendra P. Singh
The present paper entails the results of the demineralization of the Rajmahal Gondwana coals of India with Pseudomonas mendocina strain B6-1 and its signatures revealed in the X-ray Diffraction (XRD) and Fourier transform infrared (FTIR) spectra. The XRD study reveals the reduction of pyrite phase in the coal samples after bacterial treatment due to bio-oxidation of pyrite and the appearance of few new phases of jarosite. Moreover, the intensity of jarosite peaks has been noticed to increase after the bacterial treatment. The FTIR spectra of the bacterial treated Rajmahal coal samples indicate shifting of the absorption peaks as compared to the control samples. The oxidation of pyrite due to the bacterial action and its conversion into jarosite is indicated by the stretching of OH bond at 630 cm-1 peak. While the bacterial action on clay minerals in all the samples is indicated by the stretching of bonds at 1114 cm-1 to 430 cm-1 peaks.
Demineralization Study of High-Ash Permian Coal with Pseudomonas mendocina strain B6-1: A Case Study of the South Karanpura Coalfield, Jharkhand, India
(American Chemical Society, 2018) Aniruddha Kumar; Alok K. Singh; Prakash K. Singh; Asha Lata Singh; Mrityunjay K. Jha
This paper entails the results of demineralization carried out on Karanpura Gondwana coals having high ash (30.57-21.80%) and low sulfur (0.29-0.20%) contents. The coal samples were subjected to demineralization using Pseudomonas mendocina strain B6-1, and the effect of various parameters, such as pH, temperature, incubation time, and pulp density, was observed. Optimum values of demineralization were found at pH 6.0, temperature of 35 °C, 6.0% (w/v) pulp density, and incubation time of 7 days. Reduction in the mineral matter (mean of 13.72-29.10%) content led to a relative increase in vitrinite, inertinite, and liptinite macerals. Further, the treatment has also caused an increase in the useful heat value, gross calorific value, and net calorific value of coal from 4824.86 to 5192.06 cal/g, from 5396.72 to 5647.47 cal/g, and from 5059.30 to 5273.80 cal/g (mean values), respectively. The method is eco-friendly and useful in obtaining clean fuel. © 2017 American Chemical Society.
Desulphurization of Dibenzothiophene by Different Bacterial Strains: An Eco-Friendly Approach to Obtain Clean Fuel from Coal
(Taylor and Francis Ltd., 2022) Aniruddha Kumar; Asha Lata Singh; Rajesh Kumar; Pramod K. Rajak; Prakash K. Singh
Coal is an important energy resource and many deposits contain a significant quantity of organic sulfur compounds. Combustion of coal releases SO2, CO2 and other gases into atmosphere and causes negative impact on the environment. Biodesulphurization of dibenzothiophene could be a prominent method for the removal of sulfur from coal. Here we successfully employed bacterial strains to degrade dibenzothiophene, and characterized through chromatography, high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Strains of Ralstonia sp., Pseudoxanthomons sp. and Rhodococcus sp. were used in the present investigation. Only Rhodococcus sp. converted dibenzothiophene (DBT) into 2-hydroxy biphenyl (2-HBP) and was able to additionally break the C-S bond without disturbing heterocyclic structure of DBT ring. This is also complemented by blue color of Gibb’s assay which is indicative of DBT conversion into 2-HBP while brown color indicates complete consumption of DBT by bacteria. After two days of bacterial treatment, there was no further removal of DBT. DBT conversion into 2-HBP was monitored through HPLC during six days of experiment. Thus Rhodococcus sp. could be a proficient candidate for biodesulphurization of dibenzothiophene and eventually for biodesulphurizing organic sulfur rich coal with an eco-friendly and energy economical process. Though it is encouraging technique for desulphurization however more studies on coal are still required to support the industrial scale biodesulfurization. © 2022 Informa UK Limited, trading as Taylor & Francis Group.
Distribution of Inertinites in the Early Paleogene Lignites of Western India: On the Possibility of Wildfire Activities
(Geological Society of India, 2019) Pramod K. Rajak; Vijay K. Singh; Prakash K. Singh
In the present investigation 643 samples from early Paleogene lignite seams of western India have been studied to see the distribution of inertinites. These horizons are characterized by high content of charcoal occuring as inertinite in these lignites though there is no definite trend of inertinite distribution in space and time. Bhavnagar lower seam of the Saurashtra basin, Gujarat (BHL-6 band) and Gurha lignite seam of the Bikaner-Nagaur basin, Rajasthan (GU-8 band) recorded the highest level of charcoal to the tune of 25% (mmf basis) while the mean seam value of 16.6% is seen in the Seam-V of Panandhro lignite field of the Kachchh basin, Gujarat. The study is comparable with the wildfire activities of Early Paleogene period occurring in other parts of the world. © 2019, GEOL. SOC. INDIA.
Early Palaeogene Climate Variability Based on n-alkane and Stable Carbon Isotopic Composition Evidenced from the Barsingsar Lignite-bearing Sequence of Rajasthan
(Springer, 2020) Runcie P. Mathews; Rimpy Chetia; Shailesh Agrawal; Bhagwan D. Singh; Prakash K. Singh; Vikram P. Singh; Alpana Singh
The assessment of variations and the reconstruction of palaeoclimate, based on the distribution of n-alkanes and stable carbon isotope data, during early Palaeogene have been made on the Barsingsar lignite-bearing sequence associated with Palana Formation (Bikaner-Nagaur basin). The distribution pattern of various n-alkanes and the derived indices/ratios have widely been used as palaeoclimate indicators in several depositional realms. The distribution of n-alkanes in the studied sequence varies from C13 to C34. The values of calculated n-alkane parameters range from 26.20–28.39 (aliphatic chain length (ACL) index); 0.32–7.21 (low-to-higher molecular weight (L/H) ratio); 0.42–0.85 (Proxy wax (Pwax)); 0.20–0.67 (Proxy aqueous (Paq)); 0.28–5.22 (terrigenous/aquatic ratio (TAR)); 0.16–0.79 (C23/C29 ratio); 1.14–6.31 (C27/C31 ratio) and 1.47–7.02 (C29/C31 ratio). The δ13C varies from −24.8 to −26.1‰ and the TOC varies from 9.6 to 69.5 wt.%. All these variations indicate the changes in palaeoclimate from dry and warm to cool and wet conditions during the deposition of this lignite-bearing sequence. Further, it is also suggested that the climatic condition was cooler than that of the Palaeocene-Eocene thermal maximum (PETM) event. © 2020, Geol. Soc. India.
Environment of paleomire of lignite seams of Bikaner-Nagaur basin, Rajasthan (W. India): Petrological implications
(Inderscience Publishers, 2019) Pramod K. Rajak; Vijay K. Singh; Prakash K. Singh; Mahendra P. Singh; Alok K. Singh
Petrological and chemical investigations of lignites from the Bikaner-Nagaur Basin, Rajasthan (Western India) have been undertaken to understand their petrographic characteristics and the paleomire. The huminite reflectance (VRr) (0.21-0.26%) put these lignites as 'low rank C' coals. Huminite is the most abundant maceral group which is dominated by detrohuminite (densinite and attrinite). Telohuminite (chiefly ulminite-A and ulminite-B) occurs next in abundance. Liptinite and inertinite occur in subordinated amount. High GI and low TPI values indicate a continuous wet condition in the basin with a slow rate of subsidence. However, Gurha lignites, suffered few spell of relatively drier period as revealed by increased inertinite content in few bands. The study indicates a limno-telmatic swamp and a slow fall in ground water table. Petrography based models suggest a wet moor condition having a moderate flooding with increasing bacterial activity that prevailed under coastal-marshy setting during the transgressive phase. Copyright © 2019 Inderscience Enterprises Ltd.
Environmental geochemistry of selected elements in lignite from Barsingsar and Gurha mines of Rajasthan, Western India
(Geological Society of India, 2015) Prakash K. Singh; P.K. Rajak; M.P. Singh; A.S. Naik; Vijay Kumar Singh; S.V. Raju; Sanjay Ojha
The present paper contains the result of investigation carried out on selected trace elements in the less studied lignite deposits of Rajasthan, Western India. The study has been made on two new lignite deposits–Barsingsar and Gurha. The former has elevated ash content (mean 20.8%) than the latter one (mean 5.1%) and both of them have high volatile matter (mean 43.7% and 49.9% respectively). The lignite samples have been studied for selected elements like Fe, Ca, Mg, Mn, K, Na, Cu, Co, Ni, Cr, Zn, Pb, Cd and As. The elements like Cd, Co, Ni, Pb and Cu occur in high concentration when compared to the Clarke values for brown coal. Ca and Mg relate positively with organic matter in Barsingsar lignite indicating their organic source while K, Cu, Co, Pb and Cd indicate their inorganic origin. Ca might have come in contact with the organic matter during humification and would have become a part of humate. The elements like Cu, Co, Ni, Cr, Cd and Pb showing strong affinity with inertinite could have got associated with the mineral matter present in the fusinite and funginite macerals. In Gurha lignites Pb and Co have shown their affinity with inorganic matter which could have been drawn from sulphides and clay minerals. © 2015, Geological Society of India.
Evolution and Evaluation of Coal-bed Methane in Cambay Basin, Western India: Insights from Stable Isotopic and Molecular Composition
(Springer, 2023) Sanjay Ojha; Naresh K. Punjrath; Amitava Chakraborty; Prakash K. Singh
Owing to a rapid rate of depletion of conventional energy resources and to keep pace with the ever increasing energy demand, scientists all over the world are looking for some alternate source. Coal bed methane (CBM) is one of them. With the discovery of coalbed gas from an oil and gas producing basin- the San Juan basin in Colorado and New Mexico by AMOCO in early 1980’s, the attention of world-wide hydrocarbon industry shifted to evaluation of CBM potential of Tertiary basins. The Tertiary Cambay basin in Gujarat is a known onland hydrocarbon province of India and has been producing oil since 1958. During drilling for petroleum, thick Eocene coal seams are encountered at varied depths in Mehsana area and further north. In 2004, few coalbed methane (CBM) blocks were awarded in northern Cambay basin and contagious Barmer Basin. The present paper entails the results of investigation carried out for CBM in the deep-seated coals of Sanchore and Tharad area in north Cambay basin. The methane content of the desorbed gases varies from 20–68%. The stable carbon isotope study (δ13C) shows that the desorbed gas is dominantly biogenic but the compositional analysis of desorbed gas reveals significant fractions of ethane (C2) and butane (C3) indicating the gases to be of mixed origin. Further, presence of high CO2 content is observed which varies from 20–45% of the total volume of desorbed gas. The estimated mean CBM resource of the study area is ∼ 46 billion cubic meters. © 2023, Geological Society of India, Bengaluru, India.
Experimental study on demineralization of coal with Pseudomonas mendocina strain B6-1 bacteria to obtain clean fuel
(Multi-Science Publishing Co. Ltd, 2014) Asha Lata Singh; Prakash K. Singh; Aniruddha Kumar; Akhilesh Yadav; Mahendra P. Singh
We present the results of the investigations carried out on the demineralization of coal of the Rajmahal Gondwana basin of India using Pseudomonas mendocina strain B6-1. Petrographically these coals are characterized by high concentration of inertinite macerals with subordinate amount of vitrinite and liptinite macerals. The mineral matter content occurs in high concentration which gives a high ash yield. This coal contains relatively high content of major, minor and trace elements when compared with the Clarke values in coal. After the bacterial treatment a considerable reduction in the elemental content of oxygen, hydrogen and sulphur was seen. Reduction in the ash content (>5%) was achieved and variable degrees of removal of the various major, minor and trace element concentration was also noticed. Nearly 59% removal of Mn, 53% of Na, 13% of Fe was achieved among the major/minor elements while nearly 54% of As, 41% of Cd, 39% of Cu, 34% of Ni, 32% of Zn, 13% of Cr, 43% of Co and 66% of Pb could be removed. Arsenic, Fe and Ca have a strong positive correlation with the ash removal percentage indicating that the samples having increased concentration of these elements are prone to demineralization with Pseudomonas mendocina strain B6-1. Whereas the elements like Ni, Zn, Cr and Cu maintain a strong negative correlation with the ash removal percentage indicating that their enrichment could have hampered the process of demineralization. © 2014 Energy Exploration & Exploitation.
Geochemical and mineralogical assessment of environmentally sensitive elements in Neyveli lignite deposits, Cauvery Basin, India
(Springer, 2024) Pramod K. Rajak; P. Gopinathan; Aniruddha Kumar; Om Prakash Kumar; Ishwar C. Rahi; Anupam Sharma; Prakash K. Singh; Amit Karmakar
This research work presents an examination of the concentrations and modes of occurrence of environmentally sensitive elements within lignite deposits, located in Neyveli, within the Cauvery Basin of India. Coal is one of the most complex geologically formed materials, consisting of organic and inorganic matter. The inorganic mineral matter including the crystalline minerals, non-crystalline mineraloids, and elements with non-mineral associations. These lignite samples underwent complete analysis encompassing macroscopic, microscopic and geochemical assessments. The analysis reveals that the total mineral matter (MM) content, comprising significant proportions of sulphides, carbonate and argillaceous components. Geochemical characterization further elucidates the lignite’s properties, with proximate analysis yielding values such as ash, volatile matter and fixed carbon and the Ultimate components analysis reveals the carbon, hydrogen, nitrogen, sulphur and oxygen. Inorganic mineral matters play a significant role in coal utilization, and also such modes of occurrence of elements provide useful geochemical information on coal formation and coal-bearing basin evolution. In this paper, we assess the associations of elements and minerals, as well as the associations of selected elements including environmentally-sensitive (e.g., S, As, U, and Hg), and some major elements (e.g., Ca, Mg, Fe, Al, and Ti) that have largely occurred in non-mineral forms in these low-rank coals. And also, comparative analysis is conducted between the concentrations of elements within the lignite samples and the values reported for World Clarke Brown Coals (WCBC). Particularly, some of these elements exhibit significantly high environmental sensitivity, demanding careful consideration in lignite extraction and utilization practices. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.