IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
Not a member yet
2618 research outputs found
Sort by
Tuning the assembly of MgNiO2 nanoparticles-infused polysulfone membranes for efficient gas separation: The selectivity-permeability conundrum
No full textThe persistent surge in global energy demand, coupled with escalating environmental apprehensions, has
underscored the imperative for adept and sustainable gas separation technologies. Mixed matrix membranes
(MMMs) have surfaced as a promising avenue to confront these multifaceted challenges, synergistically har-
nessing the strengths of conventional polymeric membranes and nanoparticle reinforcements. In this work,
MMMs have been tailored for gas separation applications by incorporating MgNiO2 nanoparticles as an additive
into the polysulfone (PSf) matrix as they provide additional space (in the form of nanoscale voids) for gas
diffusion, facilitating faster gas transport, promoting selective permeation of specific gases, and enhancing
membrane stability, in addition to their versatility, ease of preparation, cost-effectiveness and high activity. The
crystalline nature of MgNiO2 nanoparticles, as characterized by finely tuned grain sizes, has been validated by
powder X-ray diffraction (XRD) analysis. Gas permeation experiments on the developed MMMs encompassing a
diverse range of pure gases and gas mixtures have been performed. Among the different MMMs investigated,
PSM1 with a composition of 100 mg MgNiO2 nanoparticles has yielded substantial enhancements in permeability
and selectivity. The PSM1 membrane exhibits remarkable permeance of 56.9 for H2, 16.3 for CH4, and 15 GPU
for CO2, having ideal selectivity ratios of 3.5 and 3.8 for H2/CH4 and H2/CO2, respectively. Finally, this work
provides new directions for improving the trade of relationship between the selectivity and permeability of gas
mixtures under relevant process conditions
In-situ synthesis of quaternary alkylammonium ligand capped organic-inorganic hybrid halide perovskite for high pure green luminescence in display application
No full textThis study delves into the intricate dynamics of ligand engineering for the synthesis of Methyl
Ammonium Lead Bromide (MAPbBr 3) nanocrystals (NCs), which exhibit immense potential in
optoelectronic and photovoltaic applications. Our focus centres on the role of the quaternary
ammonium molecule CTAB as a ligand in stabilizing MAPbBr 3 NCs. This also addresses the
challenges related to the stability and surface defects of NCs that hinder their commercial viability.
Employing a modified ligand-assisted reprecipitation technique (LARP) with a dual solvent system,
we optimized the CTAB concentration to 0.05 mmol, resulting in MAPbBr 3 NCs with an impressive
88% quantum yield. XPS and FTIR analyses confirm the presence and binding of CTAB on the NC
surface. The MAPbBr3 -CTAB NCs exhibit higher exciton–phonon binding energy, enhancing their
optical properties. Despite an unfavourable geometric fit, CTAB is effective in surface defect
passivation due to its binding, solvation, and desorption energy during the dynamic binding process.
2D-DOSY NMR reveals approximately 66% CTAB bound to the NC surface. A comparative study
involving MAPbBr 3 -OA, OLA, and MAPbBr3 -CTAB deposited on LEDs demonstrates the superior
performance of the latter, achieving a luminous efficiency of 42.18 lm W−1 at 1.2 ml deposition. These
findings highlight the efficacy of CTAB in achieving high-purity green luminescence, aligning with
BT.2020 display colour standards and paving the way for advanced optoelectronic applications. The
successful synthesis and improved performance of MAPbBr3 -CTAB NCs underscore their potential
as a promising material for future optoelectronic and photovoltaic technologies
Application of Optical-electron Correlative Microscopy for Characterization of Organic Matter
No full textApplication 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 abovementioned 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
Prospect for recycling critical elements in combustion residues of coal, lignite, and biomass feedstocks
No full texthe combustion residues derived from coal, lignite, biomass, and spent wash could be recycled to extract critical
elements required for energy transition. To recycle these elements from the combustion residues, it is necessary
to understand their chemical mode of occurrence in the ash. This study presents the content of critical elements
and their chemical mode of occurrence in coal, lignite, biomass, and incinerator ash. Lignite ash, rich in Ca and
Si, offers Sc (31 mg/kg) and Nd (212 mg/kg), while coal ash, dominated by Si and Al, contains Ga (44.8 mg/kg).
Biomass and spent wash ash, characterized by K, Ca, and S, present substantial potential for potash and Sc.
Lignite ash primarily contains rare earth elements (REEs) in metal oxide-bound fractions, whereas in coal ash, the
REEs are associated with the hard mullite or quartz phase. Biomass and incinerator ashes have significant water-
soluble potash, and the Sc is associated with metal oxides. Green acids can extract critical elements from lignite,
biomass, and incinerator ashes, but extracting from coal ash requires harsh conditions. Future research should
concentrate on green extraction processes considering the chemical patterns of occurrence of critical elements
A comparative study of molecular structure and combustion behavior of coal and its separated vitrains
No full textA systematic study has been conducted on two coking coals and their separated vitrains to understand the macromolecular structure and their thermal behavior. The structural parameters have been determined by using XRD (X-ray diffraction), Raman spectroscopy, FTIR, Solid-state 13C NMR and TG/DTG–DSC. The proximate and ultimate analyses results indicate that vitrinite is the major organic component of coal and it is type III kerogen having H/C ratio in the range of 0.58–0.72 and O/C ratio in the range of 0.09 to 0.16. The inter-layer spacings, crystallite size, the average number of the aromatic layers, aromaticity, and rank of demineralized coal and vitrain as obtained from XRD studies vary in the range of 3.49–3.70 Å, 13.24–16.72 Å, 3.60–4.74, 0.72–0.80 and 2.62–3.98 respectively. The values of aromaticity, rank and inter-layer spacing of vitrain are higher however the crystallite size and the average number of the aromatic layer are lower than that of respective demineralized coal. Raman spectra results show that vitrain is more graphitic and stable in nature compared to their bulk coal and the structure of coal gets disordered during demineralization. The FTIR spectrum shows that carboxylic (–COOH), carbon–Carbon double bonds (–Cdouble bondC–), carbonyl/carboxyl (Cdouble bondO), methyl and methylene (–CH3, –CH2–), and a hydroxyl group (-OH) are the major functional groups. The structural parameters as obtained from FTIR studies such as aromaticity (fa)FTIR, degree of condensation of aromatic rings and aliphatic to aromatic ratio are higher in vitrain than their respective coals, while the aliphatic hydrogen to total hydrogen ratio (Hal/H) of demineralized coal is higher than the raw coal and vitrain. The 13C NMR spectra show the fraction of unsaturated carbon is higher in vitrain than the respective raw coal. The thermal analysis result shows the reactivity of the samples increases in the order of demineralized coal > vitrain > raw coal and the activation energy increases in the order of raw coal > demineralized coal > vitrain
Mineralogical and geochemical characterization of coal debris from major coal fields in India: Implications on respirable dust hazards
No full textCoal mining activities have major impact on the surrounding regions through flying coal dust particles. In this study, we investigate the differences in mineralogy and geochemistry between the deposited coal dust and the respirable fractions of coal dust samples collected from the coal mining regions of Jharia and Raniganj coalfields in India. The coal dust samples were investigated in detail through various analytical techniques including FE-SEM, TGA, and particle size analyzer. The proximate analysis of the coal dust indicated that the ash content is 75%, moisture 0.5%, volatile matter 8.4%, and fixed carbon 16% in the Jharia coal fields, while the respective values of Raniganj coal values are 68.3%, 2.8%, 14.6%, and 14.2%. The average carbon content in the Raniganj coal dust particles is higher than that of Jharia (22.62 vs. 21.50%) and suggest that the coal dust particles were transported from the coal mining areas. The scanning electron microscopy images suggest that the coal dust samples have spherical and irregular morphologies. The carbon and sulphur in these samples were possibly derived from the organic matter of the coal materials, which were transported by air as dust particles. The particle size distribution of the coal dust samples revealed that 75–95% of these by volume are in the fraction of <600 μm. It can be inferred that the relatively fine particles of the coal dust samples contained 70% of ash comprising of mostly silica and clay as maximum respirable dust, which is hazardous to both human life and the environment. Our study provides insights into the air pollution and health risks around mining areas
Estimation of Soil Nutrients and Fertilizer Dosage Using Ion-Selective Electrodes for Efficient Soil Management
No full textThe recent advancements in precision agriculture have led to a high demand for a portable and intelligent device capable of accurately measuring soil nutrients with reduced use of chemicals. Instead of relying on chemical-based laboratory tests, a smart portable device has been developed. The device measures soil nutrients, such as ammonium, calcium, potassium, nitrate, and chloride, and provides fertilizer dose recommendations. The device uses ion-selective electrodes, a microcontroller, multiplexer, operational amplifier, data logger, and input/output units. It reports soil health status to farmers or users via WhatsApp and e-mail. The measured soil nutrient values are uploaded to a database, which generates soil health cards and fertilizer dose recommendations. The device’s performance was compared to standard methods, with a correlation coefficient of 0.9906 for ammonium, 0.9949 for calcium, 0.9852 for potassium, 0.9716 for nitrate, and 0.9716 for calcium. The sensor-based soil nutrient analyzer demonstrated similar performance to other established standard methods when tested on 250 soil samples of agricultural fields. Consequently, this device holds great potential for utilization in soil testing laboratories as well as for on-site soil monitoring in agricultural fields, specifically for the purpose of precision farming
Tuning the assembly of MgNiO2 nanoparticles-infused poly sulfone membranes for efficient gas separation: The selectivity-permeability conundrum
No full textThe persistent surge in global energy demand, coupled with escalating environmental apprehensions, has
underscored the imperative for adept and sustainable gas separation technologies. Mixed matrix membranes
(MMMs) have surfaced as a promising avenue to confront these multifaceted challenges, synergistically har-
nessing the strengths of conventional polymeric membranes and nanoparticle reinforcements. In this work,
MMMs have been tailored for gas separation applications by incorporating MgNiO2 nanoparticles as an additive
into the polysulfone (PSf) matrix as they provide additional space (in the form of nanoscale voids) for gas
diffusion, facilitating faster gas transport, promoting selective permeation of specific gases, and enhancing
membrane stability, in addition to their versatility, ease of preparation, cost-effectiveness and high activity. The
crystalline nature of MgNiO2 nanoparticles, as characterized by finely tuned grain sizes, has been validated by
powder X-ray diffraction (XRD) analysis. Gas permeation experiments on the developed MMMs encompassing a
diverse range of pure gases and gas mixtures have been performed. Among the different MMMs investigated,
PSM1 with a composition of 100 mg MgNiO2 nanoparticles has yielded substantial enhancements in permeability
and selectivity. The PSM1 membrane exhibits remarkable permeance of 56.9 for H2, 16.3 for CH4, and 15 GPU
for CO2, having ideal selectivity ratios of 3.5 and 3.8 for H2/CH4 and H2/CO2, respectively. Finally, this work
provides new directions for improving the trade of relationship between the selectivity and permeability of gas
mixtures under relevant process conditions
Strength of In-Situ Backfill in Underground Hard Rock Mines,
No full textAn enormous amount of waste materials is generated during mineral processing, power generation and metallurgical processes. The surface disposal of tailings and coal ash creates numerous environment related problem. The worldwide application of backfilling in underground mines has resolved several issues associated with surface tailings disposal and underground mining operations. Cemented backfilling in India is in a fledgling stage and it has a virtuous scope of application in most of the underground mines. Uniaxial compressive strength (UCS) is one of the essential backfill design parameters. The in-situ backfill strength development after pouring into the stope is one of the essential criteria of backfill performance in field. Limited studies about the backfill strength development in in-situ conditions are available in literature. Hence, the in-situ cured backfill strength was determined in three underground hard rock mines with four different backfilling methods. Out of these, three cases have shown reduction in UCS as compared to lab prepared specimens by 9–33%. Only in one instance higher UCS was observed as compared to lab-based result
Pre-combustion mercury removal potential of rapid pyrolysis in high ash coal and mode of occurrence
No full textMercury is a widely known pollutant, and coal combustion is one of the largest sources of anthropogenic Hg emission. Mercury reduction technologies globally rely on flue gas treatment. However, pre-combustion techniques show immense potential. Mild pyrolysis of coal offers a promising approach for mitigating mercury emissions. This study investigated the mercury distribution and its mode of occurrence in six high ash coal samples from the Jagannath area of eastern India. The findings revealed that Hg content in coal samples ranged from 0.154-0.308 mg/kg. Majority of the mercury was bound to pyrites (60–90 %) and organic matter (5–15 %). Rapid pyrolysis at temperatures ranging from 200 to 700 °C demonstrated significant mercury removal efficiency (up to 95 %). In particular, at 400 °C with minimal loss in calorific value and mass. Though the high-temperature pyrolysis (600 °C) resulted in maximum mercury removal, but with a notable loss in calorific value and product yield. The Hg content in raw coal, initially ranging from 9 to 20 μg Hg/MJ, was reduced to 3 to 11 μg Hg/MJ in char produced at 400 °C. Further reduction was observed in char produced at 600 °C, where the Hg content decreased to between 2–3 μg Hg/MJ. This research emphasizes the effectiveness of mild pyrolysis in reducing mercury content of high ash coal, thereby facilitating the generation of cleaner energy