Fixed Carbon Value Research Articles

Optimizing calliandra (Calliandra calothyrsus) biomass pellets: Impact of particle size and bark composition

Calliandra biomass pellets offer a promising alternative energy source to replace fossil fuels. Typically, these pellets are produced by directly processing the stem and bark of the calliandra (Calliandra calothyrsus) plant without separation, aiming for manufacturing efficiency. This study investigated the quality differences between calliandra biomass pellets with and without bark and varying particle sizes. Particle sizes used were 20 mesh, 40 mesh, and 60 mesh. The pellets were made using a 12 mm diameter biomass pellet mold and a manual hydraulic press with a pressure of 3 tons. Characterization involved assessing proximate analysis, calorific value, physical and mechanical properties, and Fourier Transform Infrared analysis. The test results were compared with biomass pellet standards from Indonesia, Japan, Korea, and Germany. Results indicate that bark affects several properties, with higher ash content observed in pellets with bark due to the higher mineral content in bark. Volatile matter decreases with finer particle size, influencing combustion rate. Moisture content is higher in pellets with bark, impacting combustion efficiency and smoke production. Fixed carbon values are influenced by moisture and volatile matter content. Calorific values are generally higher in pellets without bark and smaller particle sizes. Density and compressive strength increase with decreasing particle size. FTIR analysis reveals differences in functional groups between pellets with and without bark, indicating variations in chemical composition. Overall, this research provides insight into the potential of calliandra biomass pellets with bark and without bark along with particle size as a renewable energy source.

Co-pyrolysis of plastic waste and eucalyptus waste wood for fuel pellets production: A study of fuel, mechanical, and combustion characteristics under varying binder proportion

The study explores the effect of varying molasses proportions as a binder on the characteristics of densified char obtained through the slow co-pyrolysis of plastic waste and Eucalyptus wood waste (Waste low-density polyethylene – Eucalyptus wood (WLDPE–EW) and Waste Polystyrene – Eucalyptus wood (WPS–EW)). Pyrolysis was conducted at 500 °C with a residence time of 120 min, employing plastic to wood waste ratios of 1:2 and 1:3 (w/w). The focus was on how varying the proportion of molasses (10–30 %), influences the physical and combustion properties of the resulting biofuel pellets. Our findings reveal that the calorific value of the pellets decreased from 28.94 to 27.44 MJ/Kg as the molasses content increased. However, this decrease in calorific value was compensated by an increase in pellet mass density, which led to a higher energy density overall. This phenomenon was attributed to the formation of solid bridges between particles, facilitated by molasses, effectively decreasing particle spacing. The structural integrity of the pellets, as measured by the impact resistance index, improved significantly (43–47 %) with the addition of molasses. However, a significant change in the combustion characteristics depicted by lower ignition and burnout temperatures were observed due to decrease in fixed carbon value and increase in volatile matter content, as the proportion of molasses increased. Despite these changes, the pellets demonstrated a stable combustion profile, suggesting that molasses are an effective binder for producing biofuel pellets through the densification of char derived from the co-pyrolysis of plastic and Eucalyptus wood waste. The optimized molasses concentration analyzed through multifactor regression analysis was 16.96 % with 28 % WLDPE proportion to produce WLDPE–EW char pellets. This study highlights the potential of using molasses as a sustainable binder to enhance the mechanical and combustion properties of biofuel pellets, offering a viable pathway for the valorization of waste materials.

Coal Quality Effect Analysis on Clinker Deformation in The Binungan Area, Berau Regency, East Kalimantan Province, Indonesia

Unidentified Clinker causes a loss of reserve in mine activity. Clinker is created by in situ coal heating and has certain quality characteristics. This research investigated the effect of coal quality on clinker deformation. This research is located in the Latih Formation, Binungan Area, Berau Regency, East Kalimantan Province, Indonesia. Coal quality samples were derived from 77 drillholes, consisting of 10 seams with a thickness > 2.25 m and distributed laterally and vertically. Coal quality parameters consist of Inherent Moisture (IM), Ash Content (AC), Volatile Matter (VM), and Fixed Carbon (FC). The coal quality sample is classified into the clinker seam group and the non-clinker seam group. Each quality parameter is compared with seam thickness in a scatter graph. The result of this study is that coal that has the potential to deform into clinker has a value of IM < 14.49 %, VM > 39.8%, and FC > 42.08 %, but AC is 3.63% relatively stable, or there is no correlation to clinker deformation. Among these four quality parameters, moisture significantly differs between seam clinker and non-clinker. This study concludes that the lower layer of coal or older seam in the Binungan area has a higher potential to be clinker, which is caused by increased FC and VM values and a decrease in IM value.

Influence of Pyrolysis Temperature and Time on Biochar Properties and Its Potential for Climate Change Mitigation

The thermochemical conversion of disposable bamboo chopstick (DBC) wastes into biochar is a practical strategy for converting waste into resources. This study aimed to investigate the effects of pyrolysis temperature and holding time on the physicochemical properties of DBC biochar and its potential for climate change mitigation. Properties affecting the biochar efficiency and potential for application were analyzed: moisture content (MC), volatile matter (VM), fixed carbon (FC), ash, pH, and carbon (C), hydrogen (H), nitrogen (N), and oxygen (O) content. Six different pyrolysis conditions were studied, with temperatures of 400 °C, 450 °C, and 500 °C and holding times of 20 and 60 min, at a constant heating rate. The results demonstrated that temperature and holding time significantly affected the physicochemical properties and performance of the biochar. Increases in %C, %FC, %N, and pH and reductions in %MC, %VM, %H, and %O were found when the temperature was increased at different holding times. The aromaticity increased and the polarity decreased significantly with increasing temperature and holding time. The results showed that temperature interacts significantly with holding time, and these two factors jointly affect the contents of MC, ash, FC, C, H, N, and O (R2 of 0.997) and pH (R2of 0.999). The DBC biochar obtained via pyrolysis at 450 °C and 500 °C for 20 and 60 min could be applied for climate change mitigation. The best DBC biochar was obtained at a pyrolysis temperature of 500 °C and a holding time of 20 min. This biochar showed good hydrophobicity, tremendous stability, the highest C (88.06%) and FC (76.49%) values, and the lowest ash (2.62%) and VM (19.23%) contents. Doi: 10.28991/HEF-2023-04-04-07 Full Text: PDF

Chemical Composition and Energy Evaluation of Abies spp. and Pinus spp. Sawdust Collected as a Byproduct of the Primary Wood Sawing

The aim of this paper is to chemically evaluate the byproducts of the primary processing of genera Abies and Pinus, to determine the possibility of using them as solid biofuel. Ash percentage, volatile matter and fixed carbon values were determined by proximate analysis. The basic chemical composition includes the determination of extractives content, lignin and holocellulose. Ash microanalysis was performed with an X-ray spectrometer and the calorific value of the samples was determined by using an AC600 calorimeter. The results of this research varied as follows: the content of inorganic substances (0.33% to 0.41%), volatile matter (88.54% to 82.57%), fixed carbon (11.13% to 17.06%), extractives content (5.37% to 17.82%), Runkel lignin (27.33% to 30.97%), holocellulose content (58.53% to 69.56%) and calorific value (19.09 MJ·kg-1 to 20.42 MJ·kg-1). According to the X-ray analysis, the most abundant elements were potassium, calcium and magnesium; whereas no heavy metals were found. The results of this research show that the two genera studied here are suitable for solid biofuel production.

Physical and Chemical Characteristics of Agricultural-Plastic Wastes for Feasibility of Solid Fuel Briquette Production

In recent years, the world has witnessed an enormous effort to find a replacement energy source that is more environmentally friendly and renewable. Face masks that contain plastics lead to another management problem as they are non-biodegradable. Thus, by turning agricultural waste with plastic waste as an additive into beneficial products like briquettes, a solid waste problem can be minimized. In this study, Imperata cylindrica and mango peel commonly found in Malaysia were anticipated to boost the properties of solid fuel briquettes. Thus, the characterization of Imperata cylindrica, mango peel, and face mask waste as raw materials for the production of solid fuel briquettes is discussed in this paper. Proximate and ultimate analyses as well as Fourier transform-infrared (FTIR) were conducted to obtain the properties of the raw materials. FTIR results showed that face mask waste contained a methyl type group (CH3), and both agricultural wastes contained an oxygen type group (C–O–H). Based on the proximate analysis, face mask waste, mango peel, and Imperata cylindrica had low moisture contents, where mango peel had the highest moisture content (5.2%) followed by Imperata cylindrica (&lt;1%) and face mask waste (&lt;1%). Imperata cylindrica had the highest volatile matter content (94.6%) and the lowest ash content (2.3%), while mango peel contained the highest fixed carbon value, which was 16.1%. From the analyses conducted, face mask waste had the highest calorific value (26.19 MJ/kg−1). Face mask waste contained 63.6% carbon and 10% hydrogen. Meanwhile, Imperata cylindrica and mango peel contained 44% and 40% carbon and 6.15% and 6.95% hydrogen, respectively. The characteristics and properties of face mask waste, mango peel, and Imperata cylindrica are significant for the contribution of the optimal ratio of these materials to form solid fuel briquettes.

The continuous carbonisation of rice husk on the gasifier for high yield charcoal production

The aim of this research was to new design and develop a metal kiln for a continuous carbonisation of rice husk on the downdraft gasifier, utilising flue gas, to produce high yield rice husk charcoal. The cylindrical metal kiln was constructed of a steel pipe, 114 mm in diameter and 510 mm in length. The screw conveyor, which rotates at 3 rpm inside a cylindrical metal kiln, is powered by a 24 V DC motor. The rice husk pyrolysis is caused by direct heating from the flue gas. The flue gas was obtained from the burning of some parts of the rice husk in combination with the pyrolysis gas in the reactor beneath. The results showed that the pyrolysis temperature ranged from 460 to 475 °C. The capacity operation of the reactor was 11.237 kg (rice husk)/h and the rice husk charcoal could produce 3.565 kg (charcoal)/h. The yield of rice husk charcoal was 36.97% (by weight). The proximate analysis properties of rice husk charcoal have a volatile matter of 12.75% (by weight), a fixed carbon value of 48.89% (by weight), and a high ash content of 36.13% (by weight). The higher heating value of the rice husk charcoal is 19,859 kJ/kg. The energy conversion efficiency from biomass to charcoal and the high reactor's thermal efficiency were 48.57% and 41.46%, respectively. The rice husk charcoal obtained from this research is suitable for use as a material in the production of charcoal briquettes, and it can be mixed with other organic materials to make organic fertilizers that can be used instead of chemical fertilizers. This cuts costs for farmers.

The synergy between pristine rice husk biomass reuse and clean energy production

The present study explores the potential of yielding high-end value briquettes from pristine rice husk biomass, an agricultural waste found in Ghana, as a cleaner source of energy. Rice husk biomass was prepared with different binders and moulded into briquettes. The briquettes passed the fragility test except those with a clay binder. The average ash content for the briquettes was 97.45 %. The highest ash content of 98.45 % was recorded at 60 % clay and 40 % starch binders, and the least value of 96.54 % at 50 % cassava-starch binder. Very low values of volatile matter and fixed carbon values ranging from 1.06 % to 2.14 % and 0.49 % to 1.68 % respectively were obtained. The highest calorific value of 13.67 MJ/kg was observed for briquettes with 50 % cassava-starch binder level. The quality measurement of the finished briquette established its suitability as a clean energy source and household fuel.

The Effect of Wood Tar and Molasses Composition on Calorific Value and Compressive Strength in Bio-coke Briquetting

Biomass-based materials have the potential to replace conventional cokes for blast furnaces in the steel manufacturing study. Biomass as a renewable energy source can reduce the consumption of coking coal. The current challenge is saving fossil energy and waste management. The steelmaking industry with environmentally friendly processes and high energy efficiency is expected today. Many researchers have partially developed biomass as an alternative renewable resource to replace fossil fuels. This study aimed to determine the effect of composition the blending ratio of wood tar and molasses as a binder on the calorific value and compressive strength of bio-coke. The carbonization of redwood waste to produce high-quality charcoal was carried out at 500 °C with a kiln rotation speed of 20 rpm and a slope of 5°. The resulting charcoal showed a promising result with a 23.87 MJ/kg calorific value. The carbonization process of the redwood increased the fixed carbon value by up to 130% and the calorific value by 40%. The second part of this study focuses on bio-coke production by blending coking coal with redwood charcoal at 90:10 wt%. The coking coal and the redwood charcoal particle sizes were 40 and 50 mesh, respectively. A 15 wt% binder was added to increase the compressive strength of the bio-coke. The binder composition ratios of molasses: wood tar were 15:0, (12.5:2.5), and 10:5 wt%. The briquette was pressed using a cylinder die with a height: diameter ratio of 2.7:5.0 cm, then compacted up to 20 MPa followed by heating at 1100 °C for four hours. The bio-coke with a binder composition of 2.5 wt% wood tar + 12.5 wt% molasses produced a compressive strength of up to 5.57 MPa with a sulfur content of 0.8 wt% and produced a calorific value of 31.25 MJ/kg with an ash content of 9.6%. The study showed that the bio-coke produced meets some requirements for steelmaking industry.

Upscaling Severe Torrefaction of Agricultural Residues to Produce Sustainable Reducing Agents for Non-Ferrous Metallurgy

Torrefaction of almond shells and olive stones, which are typically considered agricultural waste in the southern regions of the European Union, was investigated in this work for application as reducing agents in the metallurgical industry. Four different temperatures were tested: 250, 280, 300 and 350 °C. The evolution of the solid yields with the temperature was determined with TGA measurements. This showed that the duration of torrefaction should not exceed 45 min. The kinetic profiles were successfully fitted using the pseudo-first-order rate equation (PFORE). Then, torrefaction for 45 min was systematically carried out at every temperature and for each resource in a laboratory-scale batch device. The raw and torrefied biomasses were characterized using proximate, ultimate and calorific analyses. The carbon/oxygen ratio and the heating values were increased as a result of the torrefaction severity (from 20 MJ/kg for both raw biomasses to 30 MJ/kg at 350 °C). The highest mass losses were obtained at the highest temperature (67.35 and 65.04 %w for almond shells and olive stones, respectively, at 350 °C). The fixed carbon value also increased, being higher than 67 %w for torrefaction at 350 °C. The large-scale torrefaction at 350 °C (45 min) of these biomasses was carried out in a continuous pilot plant. The solids were characterized as well, and their properties were close to those of the biomasses torrefied in the laboratory-scale batch reactor under the same conditions. This thermal treatment provided biochars with all the required properties to be used as reducing materials in metallurgy.

Detailed bioenergy investigation of Brazil biomass waste after biochemical process

The bagasse products generated after the extraction process have significant use in several industrial sectors however its application in the energy sector stands out, avoiding the use of fossil fuels. In this study an enzymatic process was applied through the Pleurotus sajor-caju fungus, for decomposition of the lignin present in the sugarcane bagasse, with the objective of improving the kinetic and bioenergetic parameters of this biomass. Detailed analyzes were carried out, such as kinetic, morphological, elementary and calorific, to verify its quality as biofuel. Values of Ea =31 kJ/mol to 65 kJ/mol, A = 1.4 105 s −1 to 3.0 105 s −1, ΔH = 26 kJ/mol to 60 kJ/mol, ΔG = 124 kJ/mol to 154 kJ/mol and ΔS = 150 J/mol to 157 J/mol for the conversion range (α) from 0.20 to 0.95, were obtained, with little variability in thermo-kinetic parameters. The HHV and fixed carbon values were 19.37 MJ/kg and 83.1%, respectively, demonstrating that this sugar cane residue has the potential to be used as a solid biofuel, after its use in the production of Pleurotus sajor-caju fungi, thus allowing to create more economic value in the sugar cane transformation chain.

Effect of addition elemental Sulfur as additive in the selective reduction process of limonite nickel ore with the presents of sodium sulfate

High temperatures in the smelting nickel ore increases the energy costs. The use of sulphur or sulphate as additives can optimize the reduction process at low temperatures through the formation of FeS compound. Biomass waste, which is palm shell charcoal, has potential as a reducing agent in the process of reducing laterite nickel ore because it has a fixed carbon value and a high heating value, besides that palm shell charcoal waste is more abundant as Indonesia’s palm oil industry develops. This research was carried out to investigate the effect of addition elemental sulphur as additives and palm shell charcoal as reducing agent in the selective reduction process of limonite nickel ore. This research used limonite ore with 1.38% Ni and 38.2% Fe content. The reduction of nickel ore was conducted at a reduction in temperature variations (950°C, 1050°C, 1150°C) with the presents of 10 wt.% additive sodium sulfate (Na2SO4) and addition 0%, 2.68% and 5% of elemental sulphur. The amount of reducing agent was stoichiometric variations (0.5, 1.0, 1.5). This research shows that the reduction process with 0% sulphur addition produced the most optimal grade and nickel recovery.

Effect of nitrogen gas flowing continuously into the pyrolysis reactor for simultaneous production of charcoal and liquid smoke

Biomass waste such as sawdust or red fruit seed waste can be processed into charcoal (carbonized charcoal) and liquid smoke simultaneously by the pyrolysis method. The charcoal process using the pyrolysis method will be more perfect if the reactor is designed in such a way that oxygen from the air is not free to enter the reactor. The small amount of oxygen that is present and enters the reactor can be minimized by flowing inert nitrogen gas into the reactor continuously during pyrolysis. In this study, the effect of flowing nitrogen gas into the pyrolysis reactor was observed with a gas flow rate of 1 liter/minute using raw materials from wood sawdust biomass waste with a pyrolysis time of 2 hours and a pyrolysis temperature of 400 oC. The results showed that the quality of charcoal products was relatively better. The yield of liquid smoke was higher than the results of pyrolysis with nitrogen gas flow compared to without nitrogen gas flow. The calorific value of charcoal without and with nitrogen gas flow is 6828 cal/gram and 7109 cal/gram, respectively, the fixed carbon value is 68.37% and 70.40% respectively, and the yield of liquid smoke is 38.87% and 40.35%, respectively.

Characterization of Biochars From Tropical Biomass

Tropical country has a large biomass provide from agricultural residue. The biomass has potential to be processed as biochar. In general, biochar can be utilized as soil amendment in order to increase the ability of soil to retain nutrients, reduce surface runoff, due to excess water, and adding biodiversity of soils that are very useful for plant growth. The biochar characteristics are strongly related to the feedstock types and also their pyrolysis method. This research aims to study the physical characteristics of tropical biochar and their potential suitability in soil improvement. The biochar was produced by slow pyrolysis method using a vertical bed kiln. The feedstock were 9 types of agricultural residue including: mango leaf, longan leaf, teak leaf, mango branch, longan branch, rubber branch, corncob, rice straw, and rice husk. Temperature of the pyrolisis process was in the range of 400 °C to 600 °C. The results indicated that the physical properties of feedstock affects the characteristics of biochar. The higher bulk density and fixed carbon value the greater yield of biochar. Compare to their raw materials, the average water content of biochar was reduced (0.2–3.85 %), while pH increased (7.06–9.9). The electrical conductivity in general also increased (0.11–2.9 ds.m-1 ). Bulk density changed, corncob, and branches materials decreased, while rice straw, rice husk and leaves materials increased. The water holding capacity was a fairly low number (4–20 %). Application of the utilized biochar as a soil amendment is to improve soil chemical properties (pH, electrical conductivity, and availability of N-P contents) and physical properties (bulk density, porosity, and water holding capacity). Application for different soil types requires different biochar characteristics, it is influenced by the type of raw material used, temperature, and combustion time.

Potential use of biomass and coal-fine waste for making briquette for sustainable energy and environment.

Biomass waste contributes 14% of the total global energy. And 15-20% of the coal-fine waste from coal mines are deposited in the rivers, ponds, etc., unused, which leads to resource wastage and environmental pollution. The present study aims utilizing biomass and coal-fine waste for producing biomass-coal briquettes without using a binding material. Three different average sizes 50, 134.3, and 199.7μm of biomass mixture (bagasse, groundnut shell, and woodchips) and coal-fines were used to make different ratios of biomass and coal mixture briquettes. Then, it is subjected to proximate, scanning electron microscope/elemental (SEM/EDX) and thermo-gravimetric analysis (TGA) to understand its property. Proximate analysis results revealed that the biomass waste has the low ash, sensible fixed carbon, and high volatile matter content. A briquette of biomass: coal = 7:1 ratio 50-μm particle size case was chosen for SEM/EDX and TGA analysis since it holds reasonable fixed carbon value comparatively. SEM analysis revealed irregular surfaces, cracks, cavities and longitudinal cracks, veins distribution all around, ups and shallows on the surface and it is the most favorable condition for fuel combustion since oxidant reaches the core of the fuel with less resistant. TGA reconfirms the spontaneous burning characteristics of the entire volatiles and fixed carbon. EDX analysis shows that the carbon and potassium are the two major elements present in the tested briquettes.

Preliminary study of activated carbon from water chestnut (Eleocharis dulcis)

Preliminary study of activated carbon from water chestnut (Eleocharis dulcis) has been done. The water chestnut plants, which were taken from Barito Kuala regency, South Kalimantan, were carbonized at 400 °C. The carbonized time were varied in 1 and 2 hours. Then the carbons were activated by KOH and H2SO4 solutions. The activated time were also varied in 1 and 2 hours. The physical-chemical properties of water chestnut charcoal, such as water content, ash content, volatile and fixed carbon values, before and after activated, were characterized. The results showed that the water content, ash content, volatile and fixed carbon values of activated carbon were in the range of 5.63-12.17%; 10.95-17.22%, 41.78-56.18% and 34.66-45.05%, respectively.

Briquettes Produced With a Mixture of Urban Pruning Waste, Glycerin and Cassava Processing Residue

The briquette is considered a solid biofuel, made from the compaction of lignocellulosic residues used for the generation of energy. This work aimed to study the production of briquettes from mixtures of Urban Pruning Waste (RPU) (pruning of leaves and thin branches of trees), glycerin and cassava bagasse (Manihot esculenta). Samples of RPU, cassava bagasse and glycerol were mixed to yield treatments T1 (100% RPU), T2 (92% RPU and 8% cassava bagasse), T3 (97% RPU and 3% glycerin), T4 (89% RPU, 8% cassava bagasse and 3% Glycerin), T5 (94.5% RPU, 4% cassava bagasse and 1.5% glycerin) and T6 (control). Following this step, physical, chemical and energetic analyses (moisture content, volatile material content, fixed carbon and ash content, superior, inferior and useful calorific value, mechanical resistance, apparent and energetic density) of the briquettes were carried out. Treatment T2 had a lower fixed carbon value and volatile content, as well as higher ash content and mechanical strength. The percentages of carbon, hydrogen and nitrogen did not differ statistically between the treatments. The higher, lower and useful heating values were higher in treatment T3. The results showed that treatments T1, T2 and T3 were more efficient, producing briquettes with properties that meet market specifications, besides presenting great energetic potential, being good substitutes for firewood.

A comprehensive investigation of hydrothermal carbonization: Energy potential of hydrochar derived from Virginia mallow

In this study, the effects of temperature, residence time and biomass to water ratio on hydrothermal carbonization of Virginia mallow were conducted. The main goal of this research was to investigate hydrochars derived from Virginia mallow in order to assess their fuel properties. Proximate, ultimate and high heating value analyses were used to establish the chemical energy content of raw biomass and hydrochars. TGA, SEM, BET and FTIR were performed to discuss the combustion characteristics and changes in the surface of the material. Temperature was found to be the main factor influencing the conversion of Virginia mallow during the HTC process. It was confirmed by the properties of hydrochar derived at 220 °C for 5 min which was as carbonaceous (51.8% carbon content) and reactive as that obtained at 200 °C for 60 min (52.5% carbon content). A sample pretreated at 200 °C for 90 min had the highest fixed carbon value (16.29%) when compared to raw feedstock (5.63%). In the resulting reduction of mass found in the hydrochar, an increase in the energy densification ratio as well as better combustion stability were also observed. Detailed analysis of the Results confirmed that the HTC is a promising method for producing energy-dense solid biofuel.

Proximate, ultimate and calorific value analyses of paper industry sludge at different moisture content

Paper industry has a big potency of energy that can be reused in its sludge. However, the water content of the sludge is still high and need to be dried. In this study, the characteristics of the sludge at different water content are explored. The sludge is collected from paper industry in Sumatera Utara province of Indonesia mainly at 70% water content. The experiments are carried out at lower water content that is from 10% to 60%. The proximate and ultimate analyses are carried out and the calorific values are discussed. The objective is to explore the potency of the sludge if it is employed as solid fuel. The results show that reducing water content of the sludge affects the characteristics of the sludge. The lower water content increases fixed carbon value, calorific value and volatile matter.

Evaluation of change in biochar properties derived from different feedstock and pyrolysis temperature for environmental and agricultural application

In recent years, the application of biochar has increased significantly for sustainable and efficient carbon sequestration, improving soil quality and enhancement of plant growth. The biochar is mostly made from agricultural residues and waste materials. The objective of this study was to assess the changes in physicochemical, surface morphology, and mineral composition of different biochars with varying pyrolysis temperature. Eighteen different types of biochars were prepared through pyrolysis of feedstock at four different temperatures (350 °C, 450 °C, 550 °C and 650 °C). The feedstock used for the preparation of biochar were organic waste materials such as pine saw dust, rice husk, food waste, poultry litter and paper sludge. Pyrolysis temperatures and feedstock types significantly influenced biochar properties. For instance, pH of poultry litter and paper sludge biochar has increased from 6.2 to 10.3, BET surface area of saw dust and rice husk increased from 3.39 to 443.79 m2 g−1 and 11.61 to 280.97 m2 g−1 while cation exchange capacity value decreased with the increase in temperature. Paper sludge and poultry litter had the highest ash content value (57.20 ± 0.02 and 44.10 ± 0.02) whereas saw dust, rice husk and food waste biochar have highest fixed carbon value (55.31 ± 0.15, 48.47 ± 0.31 and 58.85 ± 0.22) at 650 °C. Degree of aromaticity increased and polarity reduced significantly with pyrolysis temperature. Rice husk and saw dust biochar prepared at higher temperature were more stable among all and thus recalcitrant in nature. X-ray diffraction results revealed mineral like quartz in saw dust and poultry litter biochar, sylvite, potassium iodate, calcium sulfide in food waste biochar and calcium carbonate in paper sludge biochar. Scanning Electron Microscopy showed increase in number of pores as well as pore size specially for the saw dust, and rice husk biochar. This study suggested that biochar prepared at higher temperature (550 °C and 650 °C) are more suitable for carbon sequestration and agricultural purpose.