Rice husk is counted as an agricultural waste that results in environmental problems during its handling. In this work, rice husk was used as raw material for producing liquid biofuel (PYROLYSIS oil) via PYROLYSIS. The PYROLYSIS reaction was carried out at TEMPERATUREs of 450, 500, and 550 ° C for 1 hour. The PYROLYSIS oil was collected and weighted for every 10 minutes. The results showed that the increase in PYROLYSIS TEMPERATURE caused the yield of PYROLYSIS oil to increase. The properties in the term of heating value also increased while viscosity and density of PYROLYSIS oil decreased. These properties were almost similar to diesel oil with a slightly lower heating value. The proposed model using the single reaction model and two stages model were fit to represent the mechanism of rice husk PYROLYSIS reaction in this study. However, the results of two stages model gave a lower error than those of the single reaction model. Furthermore, the rate of PYROLYSIS reaction at various TEMPERATUREs could be determined using the kinetic data obtained from the developed model. This information would be useful for designing the PYROLYSIS reactor especially for producing biofuel (PYROLYSIS oil) from the rice husk.

The soils of desert areas are mostly low in organic matter and may fluctuate greatly in terms of acidity. Biochars are one of the materials used to improve and modify some soil characteristics. This compound is very resistant to decomposition and remains in the soil for a longer period, reducing agricultural waste and turning it into a soil conditioner. This leads to keeping carbon in the soil, increasing food security, increasing biodiversity, and reducing deforestation. In this research, an attempt was made to investigate the biochar of fodder beet plant waste produced at different PYROLYSIS TEMPERATUREs and its physical and chemical characteristics. For this purpose, fodder beet wastes were collected from settlements around Birjand and after being crushed and air-dried, they were pyrolyzed in an electric furnace under limited oxygen conditions at a TEMPERATURE range of 300-700 degrees Celsius. Then, the characteristics of the produced biochars were performed with 3 repetitions of measurements and statistical analyses with SPSS software. The results of this research showed that the characteristics of biochars changed significantly with TEMPERATURE change. The highest yield percentage (59%), organic carbon (56.33%), total nitrogen (0.53%), water retention (0.84g/g) at 300 and 400 degrees Celsius, and the highest amount of ash (% 76), acidity (8.21) and electrical conductivity (0.1ds/cm) was obtained at a TEMPERATURE of 700 degrees Celsius. The percentage of carbon and the efficiency of biochar produced at TEMPERATUREs of 300 and 400 degrees Celsius were higher than other biochar produced at other TEMPERATUREs. Biochar produced at 300°C has better characteristics in terms of carbon percentage and acidity efficiency compared to biochar produced at 400°C. Although these differences were not statistically significant, due to biochar production being more economical in terms of energy consumption, it is recommended to produce biochar at a TEMPERATURE of 300 degrees Celsius.

Converting feedstock into biochar is a popular approach to overcome the disposal problem, yet the role of waste type and PYROLYSIS TEMPERATURE on biochar properties is not understood well. In this study, biochars were produced from various feedstock such as tea waste, apple wood, wheat straw and walnut shell at 300, 400, 500 and 600° C with 1-hour residence time. The results showed that increase in PYROLYSIS TEMPERATURE significantly decreased biochar mass yield. The maximum and minimum mass yields were observed in walnut shell at 300˚ C and apple-wood-derived biochars at 600˚ C by 69 and 20%, respectively. The produced biochar had pH range between 5. 3 to 9. 7, and its pH value and ash content increased significantly with increasing PYROLYSIS TEMPERATURE, except for walnut shell. Total concentrations of P, Ca, K, Na, Fe, Zn, Cu, and Mn and available concentrations of K, Ca, Mg, and P increased with PYROLYSIS TEMPERATURE increasing in all samples, except at walnut shell-derived biochar. According to CHN analysis, by increasing PYROLYSIS TEMPERATURE, the total carbon concentration increased but total nitrogen and hydrogen concentrations decreased. The pH value decreased with time until 72 hours, beyond which a near steady-state condition was attained. Relationships between pH and CaCO3-eq content of biochars were close and linear. The FT-IR spectra showed that aromatic C increased by increment in heating. Also, by increasing PYROLYSIS TEMPERATURE, the mean pore diameter decreased but micropores volume increased and led to increase in the specific surface area of biochars. The results of this study suggest that biochars produced at 300 and 400˚ C may have potential as fertilizer in calcareous soils because of low pH and EC, with high mass yield.

Organic residues processing and their reversion to soil is helpful to build up a sustainable agriculture. Biochar is product of organic residue PYROLYSIS. Biochar chemical and physical characteristics are significantly affected by PYROLYSIS TEMPERATUREs and its feedstocks. Therefore an experiment was conducted to evalute some properties of biochar produced from four feedstocks viz: sugarcane bagasse, rice straw, wood sawdust and conocarpus leaves, which processed by three PYROLYSIS TEMPERATUREs vis: 400, 700 and 900° C. The treatments replecated three time and laid out in a factorial experiment with the completely randomized design. Results showed that each group of treatments separatelye as well as their interaction had significantly different effect on biochar pH, EC, CEC, specific surface area, C/N ratio and total element concentration as well as pb and cationic micronutrients availability. Increasing the PYROLYSIS TEMPERATURE from 400 to 900° C, decreased CEC in biochar drived from rice straw, conocarpus leaves, sugarcane bagasse and wood sawdust by 73/9, 37/7, 36/0 and 21/9 cmol+/kg, respectively. But increasing TEMPERATURE from 400 to 900° C, improved specific surface area of bagasse, rice straw, sawdust and conocarpus leaves biochar by 153/3, 241/1, 283/9 and 21/2 m2/g, respectively. It is suggested that at PYROLYSIS TEMPERATUREs of 400° C with prioritize of biochar derived from conocarpus leaves, 2-rice straw, 3-sugarcane bagasse and 4-wood sawdust can be used to improve cation exchange capacity as well as improving available nutrients reservoir.

Biochar has attracted the attention of many researchers because of its ability to improve soil fertility, immobilization of pollutants, as well as a suitable method of carbon sequestration and as a carbon reservoir. In order to investigate the effect of PYROLYSIS TEMPERATURE and type of organic residues on physicochemical properties of biochars, a completely randomized designe as a factorial experiment was designed with two factors of organic residues type (wheat straw and walnut and almond bark) and PYROLYSIS TEMPERATURE (300 and 500° C) in three replicates. The results showed that EC, pH, ash, and CEC of biochar increased at PYROLYSIS TEMPERATURE of 300° C. By increasing the PYROLYSIS TEMPERATURE to 500° C, the amount of organic carbon (OC), CEC, and surface functional groups of biochar decreased compared to biochar produced at 300 ° C whereas pH, ash, and EC increased. The highest EC, pH, water soluble materials, ash, and the lowest bulk density were recorded in wheat straw biochar produced at 500° C. The highest value of equivalent calcium carbonate was obtained in almond peel biochar produced at 500° C. Biochar production yield decreased and the loss of volatile compound such as CO2 increased by increasing the PYROLYSIS TEMPERATURE from 300° C to 500° C. In addition, the characteristics of biochar were dependent on type of feedstock and PYROLYSIS conditions (TEMPERATURE and time residence).

The objective of this article was to study the effect of PYROLYSIS TEMPERATURE and mineral matter on the distribution of the product of C1-C6 hydrocarbons. Pakistani lignite named as Lakhra 6B was used to study the effect of inorganic substances on the reactivity of coal. The experiments were performed using PYROLYSIS gas chromatography to investigate the activity of virgin coal, HCl acid-washed coal and acid-washed coal with (Ca(C2H3O2)2, Mg(C2H3O2)2, NaC2H3O2, KC2H3O2), added respectively. The products obtained were monitored by a gas chromatograph. The main products identified were methane, ethane, ethylene, propane, 1-butene, n-butane, 1-pentene, n-pentane and benzene. The results showed that coal conversion to methane increased with an increase in TEMPERATURE and the amount of this hydrocarbon was high among all the hydrocarbons formed. It was observed that the addition of metal ions affected the yields of the products in a selective manner. The yield of benzene was observed to be high in the case of calcium and magnesium form coals. The other cations form coals produced a smaller quantity of benzene in the TEMPERATURE range studied. From the results, it can be concluded that metal ions played a selective role in controlling the yield of C1-C6 hydrocarbons from coal PYROLYSIS in general and benzene yield in particular.

AbstractBackground and Objective: In recent years, due to the large amount of agricultural wastes, the production and use of biochar as a carbon-rich material has become very important in order to recycle plant residues, reduce greenhouse gas emissions, preserve nutrients and remove pollutants and heavy metals from the soil. This research was conducted with the aim of investigating the effect of PYROLYSIS TEMPERATURE, type of biomass and modification with mineral salts on the characteristics of produced biochars.Materials and methods: To carry out the research, a factorial experiment was conducted in the form of a completely randomized design with three replications. The experimental factors include the type of feedstock in 2 types (sugarcane bagasse and rice straw), the PYROLYSIS TEMPERATURE in 2 levels (300 and 500 ºC) and the type of biochar΄s modification in 4 models (control or without modification, modification with FeCl3, ZnCl2 and KH2PO4). At first, biochars were prepared (16 samples in 3 replicates) and then their physicochemical properties were measured and analyzed.Results: The results showed that with the increase of PYROLYSIS TEMPERATURE in control and all modified biochars, the amount of ash, fixed carbon, electrical conductivity (EC), acidity (pH), specific surface area (SSA), carbon content and C/N ratio increased and yield, volatile matter, cation exchange capacity (CEC), oxygen and hydrogen content decreased. In rice straw biochars (control and modified), oxygen content, O/C and O+N/C ratio at both TEMPERATUREs and CEC value at 500 ºC are higher than sugarcane bagasse biochars and Its SSA was less. Modification with mineral salts increased the amount of ash, yield, CEC, SSA, EC, oxygen content, O/C ratio and decreases pH, carbon, nitrogen and hydrogen content in biochars produced at both TEMPERATURE levels and two types of biomass. The highest amount of CEC was observed in sugarcane bagasse biochar produced at 300 ºC modified with phosphorus (58.94 cmol.kg-1) and the highest SSA in sugarcane bagasse biochar produced at 500 ºC modified with iron (94.49 m2/kg). The rice straw biochar produced at 500 ºC without modification with a pH of 8.83 had the highest pH value, and the rice straw biochar produced at 500 ºC modified with iron with EC of 9.23 had the highest EC value and the highest percentage of ash (49.07%) compared to other biochars. The most fixed carbon was related to unmodified 500 ºC sugarcane bagasse biochar (51.4%) and 500 ºC sugarcane bagasse biochar modified with zinc (48.7%). Th 300 ºC rice straw biochar modified with iron had the lowest percentage of fixed carbon and the highest ratio of H/C, O/C and O+N/C and in biochar modified with zinc produced at 500 ºC, these ratios had the lowest value compared to other biochars, which probably indicates their greater stability.Conclusion: The results of this research showed that the biochars produced at 300 ºC, especially the types that modified with phosphorus and iron, have properties that are expected to remove pollutants from water and soil and improve soil fertility, and the biochars prepared at 500 ºC, especially the types that modified with zinc, have the characteristics required for application in order to carbon sequestration in the soil. Of course, more research needs to be done to provide more accurate results. In general, the use of mineral salts to modify biochar can be effective in optimizing its characteristics, according to the purpose of application.