Origin Of Coal Research Articles

Petrology and association of rare earth elements in magmatically altered high-ash coal of Indian origin

The extraction of valuables from waste has gained momentum. Thermal influence alters both the organic and inorganic components of coal. Insufficient knowledge on the association of rare earth elements (REEs) with the parent matrix of thermally altered high-ash coals (63% ash) limits the potential for such coals being utilized for isolation of valuables. In this study, we analyzed the distribution and occurrence modes of REEs within a magmatically altered high-ash coal via nine-step sequential extraction, combining Tessier and BCR methods. The total concentration of REEs in the coal sample, on whole coal basis, was found to be 820 ppm, which is significantly higher than the world average. Major mineral oxides were deduced to be those of Si, Fe, Al, Ca, Mg, and Ti. Sequential extraction confirmed that about 66% of HREE and 25% of LREE were included in the residual fraction. LREEs were concluded to be primarily in ionic form, whereas HREEs were speculated to be associated with the TiO2 phase. XRD analyses showed that thermal alteration affected the dolomite phase specifically, which selectively got removed where carbonate-bound elements were assessed. Petrographic analysis supported the magmatic influence and demonstrated the presence of mosaic structures and pores containing unfused vitrinite, with a reflectance value of 3.6. To summarize, the present study pertaining to delineation of association of valuables in high-ash heat-altered coals from an Eastern coalfield in India can potentially open up new avenues for utilizing such coals, which are otherwise considered waste.

Study on the evolutionary characteristics of coal burst proneness under the action of multiple mining disturbances

AbstractCoal burst is a serious hazard in deep coal mining. To investigate the coal burst proneness evolution during multiple mining disturbances (MMD), this paper implemented a range of uniaxial cyclic loading–unloading tests coupled with acoustic emission (AE) measurement to simulate the loading–unloading effects of the MMD. The maximum load was used to simulate the highest load that the coal has endured in history, the loading–unloading rate was used to simulate the mining speed, and the loading–unloading cycles were used to simulate the number of mining disturbances. Finally, the burst proneness indexes of the damaged coal sample are measured and compared with the origin coal sample. Analysis on the experiment results suggest that, the burst proneness increases when the maximum load is 30% of the uniaxial compressive strength (UCS), interestingly, when the low loading–unloading rate is applied, 50% of the UCS enlarge the burst proneness as well. However, it decreases when the maximum load is 70% of the UCS. Sensitivity analysis indicates that the maximum load, loading–unloading rate, and loading–unloading cycles exhibit decreasing influence sensitivity to the elastic modulus, as well as to the UCS and duration of dynamic fracture. Similarly, the influence sensitivity of maximum load, loading–unloading cycles, and loading–unloading rate to the elastic strain energy index decreases, as well as to the bursting energy index. To ensure the safety of coal mining, it is crucial to avoid the disturbances that would put the coal under low loading and low loading rate.

Experimental Investigation of Ash Deposition during Co-Firing of Coal with Sorghum Pellet Using Drop Tube Furnace

Co-firing technology for biomass waste is a green energy solution for coal-fired power plants (CFPP) which is a major contributor of global carbon emission. Sorghum can become a suitable biomass as a co-combustion with coal given its versatility as a single source of starch, sugar and lignocellulose. The potential of sorghum in Flores, Indonesia is very large, it can produce approximately 48 tons/ha.year of dry sorghum biomass. Research about cofiring between coal and sorghum as a CFPP fuel is still limited. However, biomass can cause serious slagging and fouling problems in boilers. Therefore, it is important to conduct laboratory scale research to examine the effect of coal and sorghum blended which will be used as CFPP fuel. This research will focus on the aspect of slagging fouling caused by coal and sorghum blended using drop tube furnace (DTF) equipment. The co-firing composition of sorghum used in this study was 5%, 10% and 15%. Visual observations as well as ash analysis were conducted with the SS310 probe in adjusted temperature of 550 and 600C according to the wall tube temperature in the boiler to examine the ash deposit that occurred. There is a significant effect on sorghum and coal blended with a composition of 15%. There was no sticky material on probes 550C and 600C when compared to the others. However, the ash deposits that occur in coal and sorghum blended has the higher amount than in origin coal due to the high alkali content in sorghum.

Study on the sequestration capacity of fly ash on CO2 and employing the product to prevent spontaneous combustion of coal

An innovative approach of utilizing fly ash waste to sequester CO2 and employ the carbonated slurry to prevent spontaneous combustion of coal (SCC) in mining areas is proposed. This paper examines the CO2 sequestration capacity of fly ash based on novel calculation methods, and the functions of carbonated fly ash (CFA) slurry on the microstructure of coal and the inhibitory properties of SCC is investigated. Kinetic experiments demonstrate that the quantity of CO2 sequestration and the initial rate of CO2 sequestration increment generally with the initial CO2 pressure and the water-to-solid ratio. CO2 sequestration of the fly ash (Class F) amounts to 54.9 g/kg and the initial rate of CO2 sequestration gained 0.035 mol/kg/s at an initial CO2 pressure of 20 bar and a water-to-solid ratio of 6. The specific surface area and pore volume of the coal treated by the filtrate of CFA slurry were diminished. When the water-to-solid ratio of the slurry is 6 and the slurry-to-coal ratio reaches 3: 1, the crossing point temperature increments by 13.8 ℃ compared with the origin coal. The risk of SCC greatly diminishes based on the evaluating index I of the propensity of SCC, and CFA slurry demonstrates a great suppression function on SCC. The approach proposed in this paper effectively actualizes the combination of CO2 sequestration, utilization of solid waste, and prevention of SCC.

Studies on Washability Characteristics of Low-Volatile Indian Coking Coal by Differential Crushing

The effect of differential crushing on liberation characteristics has been studied for a low volatile coking coal of Indian origin through washability studies. Two parameters, namely “Index of Washability” (IW) and “Near Gravity Material Index” (NGMI), are used to describe the ease of washability. The ROM Coal is crushed to four different top sizes namely, 75mm, 25mm, 13mm and 6mm.On the basis of calculated IW it is observed that relative ease of washability increases with decrease in top size. From calculated IW values it may be said that this coal can be economically beneficiated using gravity process after crushing to -6mm size. From the calculated NGMI values, the critical specific gravities have been estimated and the values for crushing to -75 mm, -25mm, -13mm and -6 mm are 1.65, 1.68, 1.53 and 1.58 respectively. These critical specific gravity values suggest the separation at this specific gravity range is most difficult task using gravity methods. From NGMI analysis, it may be said that the NGMI values for coals crushed to -25 mm & -6mm are identical (≈ 0.18) at 17% clean coal ash content. This suggests that with similar degree of difficulty, clean coal of 17% ash can be produced from these two different crushing sizes. In order to increase the yield for the clean coal of 17% ash, the decision on blending these two size coals may need to be taken.

The effect of coal-derived humic substances and their silver-containing bionanocomposites on arginine balance in peritoneal macrophages of intact mice

Background. Antigen-presenting cells (APCs), especially macrophages, play an important role in the body defense against various pathogens. Their dysfunction and polarization are associated with most inflammatory and autoimmune diseases. The inflammatory process is regulated by activation and / or inhibition of genes differentially expressed by macrophages. Successful correction of inflammation leads firstly to elimination of inflammatory stimuli and then to remodeling and restoration of tissues and organs. It was experimentally confirmed that silvercontaining bionanocomposites based on natural humic substances (HS) obtained from coal of different origin, as well as initial matrices of these HS, are capable of activating pro- and anti-inflammatory properties of macrophages.Aim. To study cytotoxic, pyrogenic, and immunomodulatory properties (arginine balance) of initial HS samples and samples of silver nanoparticles ultradispersed in these HS matrices (HS-AgNPs) in the cell culture of peritoneal macrophages, as well as their effect on pro- and anti-inflammatory properties of APCs.Materials and methods. Cultural and biochemical methods were used in the study.Results. The study showed that the samples CHE-K, CHE-AgNPs, CHS-K, and CHP-K increased M1 macrophage polarization due to stimulation of the NO-synthase activity and inhibition of arginase. The samples CHI-K, CHIAgNPs, CHP-AgNPs, and CHS-AgNPs modulated an alternative M2 or M2-like state of macrophage activation. At the same time, HS are not cytotoxic at effective concentrations, and three out of four studied samples did not contain pyrogenic impurities.Conclusion. The use of HS and their silver-containing bionanocomposites, which have the ability to greatly affect the polarization of antigen-presenting cells, is a promising research area in correction of the inflammatory response for solving an important social and medical problem of treating chronic wounds.

Effect of Ash Content on the Pyrolysis of Indian Origin Coal

Effect of Ash Content on the Pyrolysis of Indian Origin Coal

Comparative Theoretical Analysis of Biomass and Energy Potentials of Usable Maize and Wheat Stalk Wastes: Example of Sakarya Province

With the increase in the population in the world and in our country, the energy requirement related to consumer demands is constantly increasing. In our country, although wind, sun, etc. energy sources are used in energy production, fuels of fossil origin (coal, natural gas, oil etc.) are used more in energy production. Renewable energy sources, which are alternative due to the decrease in fossil fuel reserves, negative environmental effects and inability to meet the energy needs in the future, come to the fore. In this study, Turkey Statistical Institute (TUIK) according to the 2015-2019 year data, Sakarya at the central and districts in cultivation areas for cultivated of using the amounts of maize and wheat product (da) average waste, dry matter, and volatile dry matter, methane and energy their potential has been determined. As a result of the calculations, it has been determined that the maize sap waste amount has the highest 25695.68 tons of waste and 201197.15 MJ energy potential in Adapazarı district in 2017. Among the wheat stalk wastes, in 2017, Geyve district had the highest 269.95 tons of waste and 2113.72 MJ energy respectively.

Technology of Anthracite and Solid Biofuels Co-Firing in Pulverized Coal Boilers of TPP and CHP

Introduction. International experience provides many examples of highly efficient use of biomass for heat and electricity production in coal-fired boilers. For Ukraine that has large coal deposits and a potential of solid plant biomass, such technology has not been implemented yet. Problem Statement. Given the scarcity of anthracite group coal, searching for new non-project fuels for thermal energy is an urgent task in the view of Ukraine’s commitment to increase renewable energy production and the need to comply with strict European emission standards. Purpose. Development of optimal technological and operational conditions for co-firing of anthracite group coal and solid biomass. Materials and Methods. The objects of research are pulverized Ukrainian coal and solid biomass of plant origin. Experimental research methods with laboratory and pilot plants, as well as CFD modeling have been used. Results. Blends of coal and biomass burning conditions have been studied; optimal scheme for TPP-210A coal-fired boiler has been recommended; balance calculations in the joint torch that burns anthracite and solid biofuels have been made; according to the chosen design scheme a burner for biomass and coal co-firing for coal-fired boilers TPP-210A have been implemented and preliminary design of the burner has been prepared. The project can be used at any TPP-210A power boiler units, and with minor changes at most boilers that burn anthracite and lean coal. Conclusions. The use of 8-12% of biomass by heat can essentially intensify the processes of anthracite coal. It is recommended to supply biomass pellets from a separate tank via a special mill to the burner where fuel is injected into the pipeline with a conical divider at output. 3D modeling of co-firing has shown a temperature flow and a fuel burn-out growth. A preliminary design of the boiler burner TPP-210A for co-combustion of anthracite and 10% biomass has been made.

Thermodynamic Modelling of Effect of Flux on the Liquidus Temperatures and Phase transitions in Coal Ash

Abstract Plant shutdowns due to the accumulation of ash materials in the boilers is a commonly practiced problem in thermal power sectors. Cleaning of ash products at regular intervals need to be necessary for maintaining the good furnace operation conditions. Use of slagging technology is the best practice for the removal of high temperature ash products, in which the melting temperature of ash is lowered by using the additive technology. In this paper, the properties of ash products formed during the combustion of low grade Indian coal were analyzed in terms of proximate and ash fusion temperature analysis. The effect of flux addition on the slagging behavior of Indian coal ash was analyzed. The AFT analysis of Indian origin coal ash shows that it is of non-fusible type. The formation of high temperature stable phases like kaolinite and quartz are the reason for high AFT temperatures in Indian origin coal.

Combustion mechanism and model free kinetics of different origin coal samples: Thermal analysis approach

Five coal samples from different origins are characterized for their pyrolysis and combustion features using coupled thermogravimetry - mass spectrometry (TG-MS). The samples are heated at temperatures ranging from 25 to 900 °C in air atmosphere under heating rates of 10, 20, and 30 °C/min. The characteristic temperatures (initial, peak, burn out), reaction intervals, mass loss rate, ash residues, ignition and combustion performances, an ignition-combustion index and the reactivities of the coal samples are calculated and the associated heating rate effects are estimated. The less reactive coal exhibits higher peak temperature in conversion and low value of ignition index and reactivity. The reactivity of the coal samples varied in between 2.31 and 7.84 x102 (1/min). The main volatile and combustion products (H2, CH4, H2O, CO, CO2, C6H6, COS, SO2) release for the corresponding TG and temperatures are estimated using online 3D measurements of MS based on their relative intensities and relevancy. Ozawa-Flynn-Wall (OFW) and Kissinger-Akahira-Sunose (KAS) type model free kinetic methods are applied to determine the activation energies of the coals which are exhibited in-between 44.6 - 75.1 kJ/mol and 50.5–96.6 kJ/mol using OFW and KAS methods respectively. The estimated kinetic constants are compared and found consistent with combustion performance parameters.

Frictional properties of simulated shale-coal fault gouges: Implications for induced seismicity in source rocks below Europe's largest gas field

We report 21 frictional sliding experiments performed on simulated fault gouges prepared from shale-coal mixtures. Our aim was to investigate the effects of local coal seam smearing on the frictional properties and induced seismogenic potential of faults cutting the Upper Carboniferous source rocks underlying the Groningen gas reservoir (Netherlands). We used shale/siltstone core recovered from beneath the Groningen reservoir plus Polish bituminous coal of similar age and origin to coals locally present in the Groningen source rocks. We performed friction experiments in velocity stepping, constant velocity, slide-hold-slide (SHS) and slide-unload-slide (SUS) modes, under near in-situ conditions of 100 °C and 40 MPa effective normal stress, employing sliding velocities of 0.1–100 μm/s and a variety of pore fluids. Samples with 0–50 vol% coal showed friction coefficients ~0.45, with minor slip weakening. Samples with ≥50 vol% coal showed marked slip-weakening from peak friction values of ~0.47 to ~0.3, regardless of experimental conditions, presumably reflecting strain localization in weak coal-rich shear bands, possibly accompanied by changes in coal molecular structure. However, re-sliding experiments (SUS) showed that slip-weakening is limited to small initial displacements (2–3 mm), and does not occur during slip reactivation. At (near) steady state, almost all experiments performed at in-situ stress, pore water pressure (15 MPa) and temperature conditions exhibited stable, velocity strengthening behaviour, regardless of coal content. By contrast, under dry and gas-saturated (CH4, Argon) conditions, or using water at 1 atm, 50:50 (vol%) shale-coal mixtures showed velocity-weakening and even stick-slip. Our results imply that faults in the Groningen Carboniferous shale-siltstone sequence are not prone to induced earthquake nucleation at in-situ conditions, even when coal-bearing or coal-enriched by smearing. However, the mechanisms controlling coal friction remain unclear at the sliding velocities studied, and the evolution of coal friction at seismic slip velocities remains unknown.

Characterization of Chemical Structure with Relative Density of Three Different Ranks of Coal from India

A comparative study of coals of different ranks having different chemical structure and petrography would be desirable to gain an in-depth knowledge of Indian coals. Here, we report structural and petrographic analyses of three different coals: Coal A (coking coal), Coal B (semi-coking coal) and Coal C (non-coking coal) of Indian origin. The vitrinite reflectances of the three coals were measured to be 1.26, 1.38 and 0.46 for Coal A, Coal B and Coal C, respectively. Size fractionation (− 3.0 + 1.0 mm, − 1.0 + 0.5 mm and − 0.5 mm) followed by density gradient separation (1.2, 1.3, 1.4, 1.6, 1.8 g/cm3) were performed for all the coal samples to study mineral matter liberation and distribution of macerals in different density fractions. Petrographic analysis of different density fractions revealed a direct proportionality of vitrinite content to swelling properties. The highest free-swelling indices (7.5 and 6.5) were observed for 1.2 density fraction of Coal A and Coal B, respectively. Fourier transform infrared spectroscopy revealed crucial information relating the degree of aromaticity and aliphaticity with observed coking properties. Specifically, aromaticity (AR1) (CHar stretching/CHal stretching, (3000–3100 cm−1)/(2800–3000 cm−1) and mean reflectance (Ro in %) were found to have a strong positive linear correlation with each other, indicative of an increase in aromaticity with coal rank.

Mass and Elements Balance of Polish and Czech Hard Coal Pyrolysis Process

Laboratory coking test is very often used for prediction of produced coke quality. The second route for results utilisation is differentiation of products and determination of its yield. There were not carried out many tests to check if mass balance sums to one. In addition to this there were not performed test to control elements balance if there were made further ultimate analysis of products. In order to control mass and elements balance there were carried out laboratory coking tests of several coals with ultimate analysis of coals, coke and by-products. There were found good correlations between some products and volatile matter in origin coal. It confirms that for them there is rational for its prediction from quality parameters of coal.

Viscosity Analysis of Indian Origin Coal by Using FactSage at Different Temperatures

Slagging of the ash inside the furnace boiler causes operational problems such as furnace shutdowns and low heat exchange efficiency. To avoid this problem, ash fusion temperature (AFT) parameter has been well accepted for determining the ash fusion characteristics since many years. In this paper, an extensive study has been conducted on the deposition characteristics of ash particles based on the viscosity and phase transformation properties in boiler operation. The FactSage thermodynamic software package is utilized for the phase transformations and viscosity predictions of coal ash in furnace operating temperatures. The effect of solid or crystalline fractions in slag phase on the viscosity is calculated by using the Roscoe equation. Calculations show that an increase in solid fractions increases the viscosity of the slag phase. AFT analysis of coal samples for the present study shows that their IDT and FT values are higher than 1340 °C and 1470 °C, respectively. The reason for the high IDT and FT in Indian origin coals is the formation of high-temperature-stable phases—tridymite and sillimanite. Furthermore, the numerical viscosity models developed by using the Roscoe viscosity equation are correlated with the experimental AFT results.

Structural evaluation of coking component of West Bokaro coal of Indian origin

ABSTRACT Detailed structural elucidation of coal is arduous owing to its complexity and structural heterogeneity. However, an understanding of structural aspect of coking coal is important, in particular, in order to develop structural analogs which could be used as substitutes for metallurgical applications. This study was performed to further corroborate previous structural data gathered for other coking components (CCs) of Indian origin. In the present study, we isolated the CC from West Bokaro coal using density separation followed by organic solvent extraction and performed a detailed structural characterization using XRD, FTIR, Raman, solid-state 13C spectrometry and high-resolution mass spectrometry. The isolated CC has been deduced to possess an ordered graphitic structure comprising of condensed aromatic rings substituted with functional groups like CONH2, OH and SO3H. The presence of graphitic backbone and sulfonic acid group has been found to be in good agreement to previous structural elucidations of Indian coal.

Cultivating the Carboniferous: Coal as a Botanical Curiosity in Victorian Culture

Coal had a ubiquitous presence in Victorian society. This article argues that its significance for Victorian society ranged far beyond its practical uses. Coal's cultural meanings were connected closely with its natural history as a fossil of the tropical forests of the Carboniferous era, and hence as a relic of the deep past. Victorian fascination with coal's origin resonated broadly from popular science to literature to discourses of domestic improvement. Accordingly, coal was not only affiliated with technological advances, but also possessed a natural aspect of profound impact on contemporary culture. As Victorians thought ferns dominated Carboniferous flora, they regarded modern fern species as the descendants of coal-producing plants and appreciated their role in British prosperity. Against this backdrop, this article engages with the fern craze of the mid-century and illuminates its obscure emergence and broad popularity.

Geochemical behavior of hazardous volatile elements in coals with different geological origin during combustion

The geochemical behaviors of hazardous elements in the combustion process of Chinese coals with different geological origins at different temperatures were studied. The analyzed coal samples were placed in a fixed bed reactor with a quartz tube and heated to six desired temperature points, from 400 °C to 900 °C with 100 °C for each interval. The mineral morphology and composition of coal and coal ash were determined by X-ray fluorescence (XRF), scanning electron microscope-X-ray Energy Dispersive Spectrom (SEM-EDS) and X-ray powder diffraction techniques (XRD). Sequential chemical extraction procedure was used to describe the modes of occurrence of selected hazardous elements in coal. The content of arsenic (As) in coal and coal ash was analyzed by inductively coupled plasma mass spectrometry (ICP-MS), and the content of selenium (Se) and mercury (Hg) in coal ash was analyzed by atomic emission spectrometry (AES) and atomic fluorescence spectrometry (AFS). The volatile characteristics of As, Se and Hg in coal were studied by thermogravimetry (TG). The results show that: 1) the mineral phases of Liuzhuang (LZ) and Huajiahu (HJH) coal samples are mainly composed of clay minerals and silicate minerals and the contents of As, Se and Hg were closely related to the organic matter and inorganic mineral in coal; 2) As mainly exists in organic matter and Se, Hg mainly exists in silicate minerals. The organic As in coal is closely related to the low-rank, low ash content and low As content of coal. The modes of occurrence of Se and Hg may be related to the low element content, low sulfide content in coal and stable sedimentary environment; 3) the relationship between volatilization rate (Vr) of As, Se and Hg elements and combustion temperature is the closest. The differences of Vr of As, Se and Hg elements in coal of different geological origin are mainly related to elements concentration and coal quality; 4) at different heating rates, the Vr curves of As, Se and Hg elements have the characteristics of “S” type, logarithmic type and linear type, respectively; The Initial stable temperature of Vr is different under the influence of element geochemical characteristics. The volatility of As reaches the maximum at 800 °C, and Se and Hg reach the maximum at 700 °C and 600 °C, respectively; 5) The heating rate and the difference of coal quality under different geological origin are important factors affecting the Vr of As, Se and Hg. The maximum weight loss temperature (TP) can be used as an important index to reflect the influence of coal quality and heating rate on the Vr of hazardous elements (As, Se and Hg).

Comparison of PM2.5 chemical composition and sources at a rural background site in Central Europe between 1993/1994/1995 and 2009/2010: Effect of legislative regulations and economic transformation on the air quality

From December 1993 to January 1995 and from October 2009 to October 2010, a total of 320 and 365 daily samples of the PM2.5 were collected at a rural background site (National Atmospheric Observatory Košetice) in Central Europe. The PM2.5 samples were analyzed for 29 and 26 elements respectively by Particle-Induced X-ray Emission (PIXE) and water-soluble inorganic ions by Ion Chromatography (IC) in 2009/2010. The Positive Matrix Factorization (PMF) was applied to the chemical composition of PM2.5 to determine its sources. The decreasing trends of almost all elements concentrations, especially the metals regulated by the EU Directive (2004/107/EC) are evident. The annual median ratios indicate a decrease in concentrations of the PM2.5 elements. The slight increase of K concentrations and Spearman's rank correlation coefficient rs 0.09 K/Se points to a rise in residential wood combustion. The S concentrations are nearly comparable (higher mean in 2009/2010, while the annual median ratio is under 1). The five major source types in the mid-1990s were ascribed to brown coal combustion, oil combustion, sea salt and dust – long-range transport, re-suspended dust and black coal combustion. The industrial combustion of brown and/or black coal (rs 0.75 Se/As, rs 0.57 Ga/Ge and rs 0.20 As/Zn) and oil (rs 0.72 V/Ni) of the regional origin dominated. In the 1990s, the potential source regions were the border area of Czech Republic, German and Poland (brown coal), the Moravia-Silesia region at the Czech-Polish border (black coal), and Slovakia, Austria, Hungary, and the Balkans (oil). In 2009/2010, the apportioned sources were sulfate, residential heating, nitrate, industry, re-suspended dust, and sea salt and dust – long-range transport. The secondary sulfate from coal combustion and residential biomass burning (rs 0.96, K/K+) of local origin dominated.The declining trend of the elemental concentrations and change in the source pattern of the regional background PM2.5 in Central Europe between the mid-1990s and 2009/10 reflects the economic transformation and impact of stricter legislation in Central Europe.

Pyrolysis, combustion and gasification studies of different sized coal particles using TGA-MS

In this research, thermogravimetric and mass-spectrometric (TG-MS) analysis and kinetics of different sized (60μm, 800μm, and 3mm) Saray (Turkish origin) coal is examined at various combustion temperature ranges. Experiments are performed at the heating rate of 40°C/min in an argon atmosphere up to combustion/gasification temperatures (850–1150°C), which is close to the conditions of fluidized bed systems for high ash coal applications. The combustion tests are performed at isothermal conditions under air and oxygen ambience. The reaction regions, peak and burn-out temperatures, mass loss, maximum mass loss rate, and ash content of the different sized coal samples are evaluated. Reactivity index is also calculated to compare the reactivity of various sized coal samples. This research also focused on the main volatile products (H2, O2, CO, CH4, CO2) of different sized coal samples on the basis of both their relative intensities and on their relevancy. Activation energy and Arrhenius constant of the coal samples are calculated using volumetric, grain and the random pore models and the results are discussed. The volumetric model showed higher activation energy values as both in the case of air and oxygen gasification.