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Biomass is a renewable carbon source for producing chemicals and liquid fuels. Biomass pyrolysis technology has achieved significant advances in replacing fossil fuels for producing high value-added products considering the current energy crisis and increasingly severe environmental pollution. However, the complex components, low calorific value, high oxygen content, and moisture content in biomass limit the further development of this technology. Currently, biomass torrefaction pretreatment, a mild-pyrolysis process, effectively reduces the moisture content and O/C ratio, improves the energy density of biomass, and enhances the quality of pyrolysis products such as bio-oil, bio-char, and bio-gas. This study reviews the effects of torrefaction pretreatment on the properties of biomass and its pyrolysis products. First, the classification and reactor of biomass torrefaction pretreatment is introduced. Then, the effects of torrefaction conditions (e.g., temperature, duration time, atmosphere, and particle size) on the basic properties of torrefied products are discussed. Furthermore, the regulatory mechanism of torrefaction on the products obtained from pyrolysis polygeneration and catalytic fast pyrolysis is elaborated. Finally, the future development directions of this field are discussed.

Positive roles of hydrothermal pretreatment and acidic hydrothermal pretreatment were researched in this study. Results of pyrolysis indicated that hydrothermal pretreatment not only significantly enriched levoglucosan (LG) content in bio-oil, but also increased specific surface area of bio-char. When acid was introduced into hydrothermal pretreatment process, the top-quality liquid and solid products acquired at a relatively low pretreatment temperature. For bio-oil, the LG content increased from 0% in rice husk (RH) to 32.68% in the sample hydrothermal pretreated in deionized water at 170 ℃ (TRH170). The highest LG content of 43.0% obtained from the sample hydrothermal pretreated in phosphoric acid solution at 115 ℃ (PTRH115). The BET of bio-char after activation increased from 2135.6 m2/g in RH to 2508.3 m2/g in TRH170. And acid addition optimized the pore distribution of activated bio-char. Both of the average pore size and efficient pore volume in micro-pore section were noticeably increased. [ABSTRACT FROM AUTHOR]

Pyrolysis is a commonly used method to produce main products such as bio-char, bio-oil and syngas. However, the practical use of syngas as a fuel is currently constrained by suboptimal properties and the necessity for specialized storage. This study investigated the impact of using syngas directly as an additional fuel for heating the pyrolysis reactor on process parameters and the properties of the resulting bio-char products. The experiment was conducted using two process variations: (i) pyrolysis utilizing syngas as fuel for co-firing with LPG, and (ii) pyrolysis using only LPG as fuel. The variables observed during the testing included the consumption of LPG fuel, process time, heating rate, pyrolysis product yields, and the properties of the bio-char. Characterization of the bio-char was carried out through proximate analysis, bomb calorimetry, thermogravimetric and FTIR analysis. Based on the experimental results it can be concluded that co-firing is able to save on the use of LPG and reduce process time. In terms of product yield, there was no significant difference when syngas was co-fired with LPG. In terms of the properties of the bio-char product, syngas co-firing pyrolysis helps in reducing the moisture content, increasing the fixed carbon content, and also increasing the calorific value up to 26855 J/g. [ABSTRACT FROM AUTHOR]

India has significant potential for producing bio-char due to the abundance of biomass resources. Numerous thermochemical and even biological techniques have been used to transform biomass into products with added value. Pyrolysis is the most practical of these processes since it offers a number of benefits for transportation, storage, and flexibility in solicitation, including turbines, combustion appliances, boilers, engines, etc. Fig. 1 shows the many types of current biomass conversion processes and their corresponding outputs. The study was conducted to look at the characteristics of various agricultural leftovers. Up until recently, the majority of BC's use in agriculture was around its use as a soil supplement. However, there are opportunities for further research in this broad area of study because there are many possible connections between different parameters, including but not limited to the BC's feedstock material, dose and its properties, type of soil, plant species and target elements/compounds of the treatment. The pyrolysis of agricultural waste to produce BC and BC-enhanced composting methods are two more related topics that have been researched. [ABSTRACT FROM AUTHOR]

In this work, the carbon dioxide capture of waste derived chars was investigated. The char samples were obtained by pyrolysis of municipal plastic waste, biomass and sewage sludge from agriculture at 400, 600 and 900 °C in nitrogen atmosphere. For further experiments, chars with a grain size between 0.315 mm and 1.50 mm were investigated. The CO2 uptake capacity of samples was tested at 40 °C through a 10 adsorption-desorption cycles using a mixture of 70 % nitrogen and 30 % carbon dioxide. The CO2 uptake capacity of the reference activated carbon was 3.71–3.90 mmol CO2/g, while that of the waste derived char samples varied between 0.76–2.33 mmol CO2/g depending on the pyrolysis temperature and the raw materials. Chars with large specific surface area obtained at 900 °C had the highest CO2 uptake capacity. Char obtained from municipal plastic waste at a pyrolysis temperature of 900 °C has the largest specific surface area. The biomass and sewage sludge derived chars contained alkali metals and earth metals in oxide form, therefore the possibility of their application for carbonization-calcination cycles was also investigated. In case of the high-temperature tests, the CO2 uptake took place at 750 °C, while the release at 900 °C. During the 10 cycles test, significant decrease in capacity up to the 5th cycle was found. The capacity of char obtained from agricultural sewage sludge was 18.68 mmol CO2/g in the first cycle, which decreased drastically to 2.88–2.96 mmol CO2/g after the 5th cycle.

The byproduct "bio-char" produced by the pyrolysis process was characterized to investigate the properties and its appropriateness for energy application. The pyrolysis reaction was carried out at 300, 350, 400, and 450 °C and 1-h reaction holding time. The analytical techniques TGA/DTG, FT-IR, XRD, SEM, CHNS, and BET were used for the characterization of the different bio-char properties. Results showed that the carbon content in rice straw bio-char increased from 42.20 to 45.33%, with increasing pyrolysis temperatures from 300 to 450 °C. CHNS, XRD, FT-IR, and TGA analysis showed that the bio-char aromatic structure was rich in carbon and it demonstrated higher bio-char carbon stability at 450 °C. With increase in temperature from 300 to 450 °C, the specific surface area of the bio-chars was enhanced (1.17 to 6.60 m2/g). At higher temperatures, biomass macromolecules decomposed completely and bio-char became more porous in nature with voids created within the bio-char matrix. During the pyrolysis of the rice straw biomass, the sharp peaks of the crystalline structure were destroyed and less intensity broader peak appeared in the pyrolysis derived bio-chars. The atomic ratio of H/C and O/C decreased with increase in pyrolysis temperature from 300 to 450 °C. These low values indicate that the reaction temperature promoted the loss of oxygen and hydrogen. [ABSTRACT FROM AUTHOR]

The valorization of black liquor, a by-product produced in considerable quantities from the paper manufacturing processes, has demonstrated the effectiveness of thermal reconversion into pyrolysis gas, bio-oil, and bio-char, a sustainable approach placing the feedstock into a circular economy concept. The present study focused on developing disposal solutions through energy recovery via pyrolysis at 300 °C and 450 °C when lignite and nanomaterials (such as Cu-Zn-MCM-41, Ni-SBA-3, or Ni-SBA16) were used as catalysts. The results were compared to those of non-catalytic pyrolysis. The use of the Cu-Zn-MCM-41 catalyst proved to be efficient for pyrolysis gas production, reaching 55.22 vol% CH4. The increase in the calorific value of the pyrolysis gas was associated with the use of the Cu-Zn-MCM-41, showing a value of 42.23 MJ/m3 compared to that of the non-catalytic process, which yielded 39.56 MJ/m3. The bio-oil resulting from the pyrolysis with Cu-Zn-MCM-41 showed the highest energy value at 6457 kcal/kg compared to that obtained with the other two nanocatalysts, Ni-SBA-3 and Ni-SBA-16, as well as that of the raw material, which had a value of 3769 kcal/kg. The analysis of bio-char revealed no statistically significant differences when comparing the outcomes from using the various nanocatalysts, suggesting their minimal impact on the energy content. [ABSTRACT FROM AUTHOR]

Zirconia is a promising candidate for many applications, especially when stabilized with metal oxide nanoparticles such as yttria and ceria. Zirconium oxide-based materials supported on carbon nanomaterials have shown excellent performance electrocatalysts due to their outstanding catalytic activities and high stability. In this work, a one-pot hydrothermal method was used to prepare porous stabilized zirconia nanoparticles with yttria and ceria (YSZ and CSZ) anchored on carbon nanosheets derived from molasses fiber waste as a sustainable source and annealing at various temperatures (MCNSs). The prepared composites YSZ/MCNSs and CSZ/MCNSs exhibit superior oxygen evolution reaction performance in alkaline medium. Various physicochemical analysis techniques such as SEM, EDX, HR-TEM, BET, XRD and XPS are employed to characterize the designed catalysts. The results showed that the doping of molasses fibers exfoliated into 2D nanosheets controlled the growth of the YSZ particles into the nanosize and increased their crystallinity. This improves the electrochemical surface area and stability, and modulates the electronic structure of zirconium, yttrium and cerium which facilitate the adsorption of OH− ions, and all contribute to the higher catalytic activity. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass is seen as a promising environmentally benign replacement for carbon-based fuels as well as a feedstock for chemicals. The energy contained in biomass can be explored using variety of ways. Pyrolysis is the first step in both gasification and combustion and is the most fundamental process in the thermochemical conversion of biomass. The pyrolysis products, namely the liquid product (bio-oil and aqueous condensate) and the char, however, could not be used as a direct source of fuel due to their limitation of quality and thus require upgradation. Thus, further advancements in pyrolysis technology, such as pre-treatment of raw materials and/or post-treatment or downstream processing of raw pyrolysis products to generate upgraded fuel with attributes similar to those of fossil fuels, are critical for effective biomass utilization. The present work provides a broad overview of the detailed biomass type and their composition, exhaustive insights about the pyrolysis process as a biomass conversion technology as well as the pyrolysis products. The most important aspects of the manuscript is to highlight the research undertaken for the upgradation of the different pyrolysis products to obtain a high quality end products that could substitute the fossil fuel. [ABSTRACT FROM AUTHOR]

Co-production of bio-char and syngas by gasification is a promising way for biomass comprehensive utilization. In this work, mainly two co-products from pinewood pellet gasification, namely bio-char and syngas were studied on a downdraft reactor. Based on the experiment, a detailed kinetic gasification model was built by Aspen Plus. The influence of temperature, ER, and steam amount was studied. Results of the pyrolysis stage show that bio-char yield during pyrolysis was about 22.8%wt and the initial pore structure was formed with a BET surface area of 36.8 m2/g. The main pyrolysis tar compounds detected by GC/MS were furfural and phenols. The gasification stage results show that H2 concentration reached the maximum of 18.62%vol at ER = 0.3. The maximum concentration of CO was 16.2%vol at ER = 0.25. The syngas yield increased with ER value. At low ER of 0.15, the syngas yield was 1.22 Nm3/kg and increased to 2.26 Nm3/kg at ER of 0.4. The carbon conversion ratio also increased with ER value. When ER = 0.4, the highest carbon conversion ratio reached 91.7%. The bio-char at gasifier outlet was a kind of highly carbonized material and the carbon content was 82.5%wt. During gasification, pore structure of bio-char was enlarged and the BET-specific surface area was about 215 m2/g. Modeling results show that by adjusting the gasification parameters, such as temperature, air equivalent ratio, and steam amount, the product distribution in the gasifier outlet could be effectively controlled. Mass and energy balance evaluation for the downdraft gasification system indicates that the pyrolysis stage and reduction stage are endothermic processes, which adsorb heat of 2.47 kW (Q1) and 2.44 kW (Q2) respectively from the partial oxidation stage. Partial oxidation stage acts as the heat source of the gasifier. Figure. Biochar and syngas cogernation system based on biomass gasification [ABSTRACT FROM AUTHOR]

With the extraction of essential oils, a large amount of residual biomass is produced and they can be a good source of functional chemicals/energy. In this study, Py-GC/MS and slow pyrolysis of eucalyptus, mentha, and palmarosa were performed at various temperatures ranging from 300–450 °C to understand the distribution and characterization of the products. Under slow pyrolysis conditions, maximum bio-oil yield for eucalyptus (50.6 wt.%) and palmarosa (42.6 wt.%) was observed at 400 °C; however, for mentha (39.5 wt.%), it was observed at 450 °C. From bio-oil analysis, mentha showed a maximum area% of carbonyls (47.72%); however, phenolics were present in maximum area% in eucalyptus (63.82%) and palmarosa (46.39%). Eucalyptus bio-char showed a higher surface area as compared to the other bio-chars. [ABSTRACT FROM AUTHOR]

The excessive use of wood plastic composites (WPCs) at construction sites owing to their outstanding properties has caused serious disposal problems recently. Thermochemical conversions, such as pyrolysis and gasification, provide a solution for WPC disposal as a means of biofuel generation in an environmentally friendly manner. In this study, air gasification of WPCs was performed over activated bio-char-based catalysts for green valorization with the aim of achieving higher H 2 generation. The KOH activation resulted in a significant increase in the Brunauer-Emmett-Teller surface area (14 times) and total pore volume (∼6.7 times), and KOH activated char was an excellent adsorbent for trapping tar, resulting in higher tar conversion into lighter hydrocarbons and H 2. In addition, KOH-activated biochar showed the highest gas yield (69 wt%) and highest H 2 selectivity (29.76 vol.%) compared to non-catalytic and non-activated bio-char catalysts. In contrast, an equivalence ratio of 0.20 was considered optimal over KOH-activated biochar for obtaining a higher H 2 selectivity (29.76%) and minimum CO 2 (17.08%). The increased catalyst/feedstock ratio from 0.1 to 0.2 also enhanced the conversion of WPC toward H 2 generation (29.76%–35.93%). Finally, the Ni loading over KOH-activated biochar provided the highest H 2 selectivity of 43% owing to the synergy of tar cracking, water gas shift reaction, and steam and dry reforming reactions. The increase in the H 2 content of the product gas was significant because it increased the overall heating value and quality of the obtained gas. Largely, this study will be a stepping stone toward sustainable valorization of WPC over activated biochar-based catalysts for higher H 2 generation. • WPC air gasification over KOH activated biohcar and Ni/KAC was performed. • KOH activation resulted in 14 times increase in BET surface area. • KOH activated biochar resulted in significant increase in H 2 generation. • Synergistic effect of added Ni and inherent AAEMs increased H 2 generation. • The biochar seems to be green and economical solution for enhanced H 2 generation. [ABSTRACT FROM AUTHOR]

The increasing utilization of non-renewable energy resources contributes to the rise in greenhouse gas emissions, leading to a growing focus on renewable resources as viable alternatives for energy production. Biomass, being a sustainable and feasible source, offers a promising solution for clean energy generation. Due to its cost-effectiveness, pyrolysis is appealing as it produces bio-oil, bio-char, and syngas. This study investigated bio-oil production using spent coffee grounds as the feedstock in a fluidized bed reactor, varying the reaction temperature and residence times. Different pyrolysis temperatures' effect on the bio-char and bio-oil yields and energy content were analyzed. The results show that higher temperatures lead to higher bio-oil yields, lower bio-char yields, and shorter residence times. The highest bio-oil yield and energy content can be produced at 500 °C. The bio-oil obtained from the spent coffee grounds has a density of 0.991 g/cm3, a viscosity of 52 cP, and a higher heating value of 41 MJ/kg. Therefore, the spent coffee grounds are a suitable feedstock for bio-oil production for sustainability.

The present study concerns the application of nano-/micro-sized fibers (bio-char of Santa Maria feverfew) in cementitious mortars. The bio-char was added @ 0, 0.05 and 0.1% by mass of cement. The addition of bio-char did not affect the setting and consistency of the mortars. The fresh density was reduced by 11%, while the followability decreased by 50%. It is concluded that the bio-char results in a light-weight cementitious material, without affecting the setting time or consistency. Bio-char produces carbon-rich materials, the use of which as building materials adds to carbon sequestration in accordance with the Sustainable Development Goals of the UNO. [ABSTRACT FROM AUTHOR]

In this study, rice straw (RS) and cow dung (CD) waste were hydrothermally processed for the recovery of bio-oil and biochar. The hydrothermal experiments were performed in a 5 L capacity reactor under the following process conditions: temperature (240–340 °C), solvent to biomass ratios of 1:1, 1:2, 2:1, 1:3 and 3:1, a time of 1 h and a pressure of 15 bar. The HTL products were characterized via FTIR, SEM and GC–MS (gas chromatography mass spectrometry). It was seen that the maximum bio-oil yield was 32.5 wt% and the biochar yield was 18.5 wt% for the 2:1 RS:CD mixture at a temperature of 320 °C. The bio-oil contained hexadecane, heptadecane, octadecane and other hydrocarbons, and their presence was confirmed by GC–MS. The biochar was analyzed, and it was used in wastewater treatment to remove the colorants. The biochar also showed some promising results in the colorants removal study, with an efficiency of more than 76%. [ABSTRACT FROM AUTHOR]

Microwave-assisted pyrolysis was applied using four magnetrons to implement a high intensity at a power density of 0.3 × 107 W/m3 with 800 g specimen size. The 23 full factorial experimental design manipulated the factors temperature, mixture ratio, and pyrolysis time, seeking to maximize %yield at minimum cost of crude bio-oil. The optimum according to model fit had a temperature of 611 °C with a 70:30 sample mixture ratio of oil palm shell (OPS) to activated carbon (AC), and time 39.6 min for a yield of 15.3% and 8.48 Thai-Baht/cc cost. The coefficients of determination were R2 = 93.99% and 94.00% for the respective models. In the aqueous phase of crude bio-oil, acetic acid was the dominant chemical component at 55.2%, whereas phenol was dominant in the bio-oil phase at 44.2%, from 400 °C pyrolysis temperature. The assessed properties of bio-char were proximate composition, heating value, specific surface, and pore volume, and these were improved compared to the raw OPS. However, these properties must be improved further to match commercial-grade activated carbon.

In recent years, palm kernel shell (PKS) has become a viable feedstock for making biofuels and value-added commodities using a variety of thermal conversion routes. Therefore, significant conservation is required for PKS as a resource for fuel production in biofuel facilities. Thus, this research was intended to elucidate the effects on PKS as a solid fuel through torrefaction and the production of bio-char and bio-oil by single and co-pyrolysis of PKS and polyethylene (PE). The PKS was treated through torrefaction at different temperatures and holding times. The optimum parameters for torrefaction were a temperature of 250 oC and a holding time of 60 min. Then the PKS and PE were pyrolyzed in a fixed-bed reactor at different temperatures and ratios. The product yield was analysed for single and co-pyrolysis of PKS and PE for pyrolysis. The properties of the product composition for single and co-pyrolysis of the PKS and PE were determined by proximate analysis, Fourier transform infrared (FTIR) analysis, and gas chromatography-mass spectrometry (GC-MS). The optimum parameter obtained for biochar and bio-oil production from co-pyrolysis of PKS and PE was at temperature of 500 oC at a ratio of 1:2 (PKS: PE). The ester and phenol compounds were increased around 19.02 to 23.18% and 32.51 to 34.80 %, respectively, while amide and amine decreased around 4.94 to 18.87% and 0.63 to 32.39 %, respectively, compared to the single pyrolysis of PKS. Therefore, the PKS and PE co-pyrolysis significantly increased the amount of phenol and ester compounds while slightly reducing the amount of amide and amine compounds in the bio-oil product. As a conclusion, biomass conservation enables the manufacturing of value-added chemicals. [ABSTRACT FROM AUTHOR]

Tobacco stem (TS) is a by-product of tobacco industry, and the conventional landfill and incineration will lead to the release of nitrogen-containing compounds and cause a series of environmental and ecological problems. The removal of alkaloids in TS is a key step for the further utilization of TS. In this study, a two-step strategy including leaching treatment and pyrolysis has been reported to remove alkaloids. The results showed that the leaching treatment not only reduces the content of nitrogen-containing compounds effectively, but also removes some metal inorganic salts. The peak area of nicotine (C10H14N2) decreased from 45.03 × 106/mg to 4.31 × 106/mg, and the number of free radicals increases. The biochar from L-TS has a lower degree of graphitization, looser structure, lower H/C ratio and oxygen-containing functional group content. With the increase of the pyrolysis temperature, the secondary reaction results in the decomposition of oxygen-containing macromolecules and aromatic compounds to form small molecules chemicals. [ABSTRACT FROM AUTHOR]

Biomass pyrolysis to produce bio-char is one of the scientific and effective means of utilizing biomass resources. Differ from previous studies, this paper explored the effect of pyrolysis temperature (400–1000 °C) on the adsorption capacity of hazelnut shell bio-char from two perspectives, including physical macroscopic structure and functional group microscopic adsorption, and the practical adsorption application tests on common 7 kinds of heavy metals in polluted water were further carried out. The results showed that the yield and adsorption of bio-char prepared at different pyrolysis temperatures varied significantly, as the temperature increased, bio-char yield and surface acid functional group content decreased, the adsorption rate on most of heavy metals increased firstly and then decreased (except for Cr6+), the adsorption capacity of bio-char prepared at above 600 °C was mainly affected by physical macroscopic structure, and at 800 °C, bio-char had a large number of pore structures, and pore structure has been fully developed, iodine adsorption value and BET specific surface area were 595.36 mg/g and 197.32 mg/m2, respectively, the adsorption effect of bio-char on Cr6+, Cd2+, Zn2+, Cu2+ and Ni2+ were best, and the adsorption rates were 45.23%, 44.14%, 60.11%, 61.28% and 65.07% respectively. It revealed that although the absorption effect of bio-chars prepared at different temperatures on different heavy metals had a great variation, large specific surface area and developed pore structure still played important role in the adsorption capacity of bio-char. These provided a reference for the application of hazelnut shell bio-char based on adsorption properties, especially absorbing heavy metals in polluted water. [ABSTRACT FROM AUTHOR]

From an environmental and economic perspective, converting harmful waste materials into value-added products is very important. This work explores using an equal mixture of chicken waste (CW) and chicken bones (CBs) as a raw material for creating more valuable products. The CW (chicken skin and fat) were de-fatted, and their solid residue leftover was blended with CBs and utilized as a pyrolysis feedstock to create bio-oil (BO) and bio-char (BC). The waste blend was thermally pyrolyzed over a range of temperatures (400–600 °C) and periods (30–150 min) numerous range of heating rates (5–20 °C/min). The highest yield of liquid fractions (61.60%) was achieved at 500 °C for 120 min at a 10 °C/min rate of heating. The BO content of the liquid fraction amounted to 25.225%. According to the FTIR outcomes, the produced BO is a complex mixture of many organic compounds, including carboxylic acids, aldehydes, ketones, esters, and hydrocarbons (alkanes, alkenes, cyclic compounds, etc.). The fuel characteristics of the synthetic BO were similar to those reported for numerous samples of BO in the literature. It also offered its suitability as a synthetic fuel for engines and a probable source of chemical feedstock. The BC leftover after the pyrolysis of the waste mixture was exploited as catalyst support. It was impregnated with different ratios (10–50%) of KOH. The typical sample (40K/BC) was identified by SA BET , FE-SEM, EDX, XRD, and FTIR spectroscopy. The efficiency and performance of the 40K/BC catalyst for transesterification of a blend of chicken fat and waste cooking oil to biodiesel (BD) were explored under diverse operating conditions. The highest BD yield (94.88%) was obtained in 90 min at 60 °C reaction temperature using a 4.0 wt% 40K/BC catalyst and 9:1methanol: lipid blend molar ratio. Additionally, the developed catalyst (40K/BC) demonstrated sustained activity after five cycles of recycling and reusing with a BD yield of >84.0%. The BD characteristics met the requirements of ASTM D6751 and EN 14,214. The ester content in the BD amounted to 96.36% based on 1HNMR analysis. [Display omitted] [ABSTRACT FROM AUTHOR]

Pyrolysis is a thermochemical process commonly used for bio-oil, bio-char, and syngas production. It is particularly attractive due to its cost-effectiveness and low environmental impact. Therefore, this study utilizes coffee waste to produce activated carbon in a slow pyrolysis reactor at different reaction temperatures and residence times. The results obtained in this study show that bio-oil yields tend to increase when moderate reaction temperatures and short residence times are used. In contrast, the bio-char yields are higher at low reaction temperatures and long residence times. The Scanning Electron Microscopic (SEM) images of the coffee waste, bio-char, and activated carbon indicate that the pore size of the bio-char tends to decrease due to heating and tends to increase in the area after using ZnCl2 as activating agent. Coffee waste is a suitable feedstock for activating carbon production.

This work studied the isotherm, kinetic and mechanism of Paraquat adsorption in aqueous solution by using corn cob biochar produced from different pyrolysis temperatures and times. The kinetic and isotherm data was fitted by the Pseudo-second-order and Langmuir models. These results showed that the adsorption capacity decreased with increasing pyrolysis temperatures during 6 hours in the order 200, 300, 400, 500, 600 °C and decreasing pyrolysis time in the order 2, 3, 4, 5, 6 hours, respectively at 200 °C. The mechanisms possibly contributed to hydrogen bonding and pore filling while π-π interaction was minor contributor in the adsorption process. Therefore, the corn cob biochar can become an alternative and promising adsorbent for Paraquat removal from an aqueous solution.

Scenedesmus obliquus is a locally available microalgae in the north-eastern region of India. Pyrolysis of Scenedesmus obliquus has been performed in a fixed-bed vertical reactor, at 350 to 550 °C temperature range with 40 °C/min heating rate. The physicochemical properties of the solid and liquid yields were investigated. The influence of temperature on the amount of product yields was analysed. The highest bio-oil yield of 20.42% and bio-char yield of 58.63% were achieved at 500 °C and 350 °C, respectively. 1H NMR and FTIR were performed for the bio-oil characterisation. The higher heating value of the bio-oil was found to be highest 32.97 MJ/kg at 550 °C. SEM-EDX, FTIR, and XRD techniques were used for the bio-char analysis and characterisation. The resulted char was found to be porous, amorphous, heterogeneous, and basic in nature. The present work suggests Scenedesmus obliquus as a potential candidate for the production of energy substituting conventional fuel sources. [ABSTRACT FROM AUTHOR]

Cotton stalks and other agricultural crop residues are available in plenty and are very potential as an energy source in Saurashtra region. These residues are sometimes, burnt in the field itself which creates an adverse condition to soil health. The objective of this research study was to develop a pyrolyser, methodology, to identify the physical-chemical-thermal properties and elemental analysis of bio-char. A small capacity (5 kg/batch) biomass pyrolyser was designed and developed for making bio-char from the shredded cotton stalk as feed stalk. Pyrolysis at various experimental temperatures 200, 300, 400 and 500 °C and residence time 60, 120, 180 and 240 min carried out for optimal parameter estimation. The quality of bio-char obtained at 500 °C temperature and 240 min is best out of the all experimental parameters. The calorific value of bio-char measured 33.89 MJ/kg and contents of nitrogen 1.56%, carbon 79.30% with C/N ratio 50.83. Conversion of agricultural residues into bio-char, bio-oil and pyro-gas will be a good option to be used as fuel and a safe sustainable soil amendment of bio-char to improve fertility. [ABSTRACT FROM AUTHOR]

Biomass‐derived char (bio‐char) is a stable and concentrated form of carbon that finds multiple applications from carbon sequestration to catalyst. The ambient conditions during bio‐char production play a major role in determining its physico‐chemical characteristics. This study employs a design optimization (RSM) technique to analyze the slow pyrolysis of rice husk under two different environments—inert (N2) and reactive (CO2), and analyzes the bio‐char produced. The slow pyrolysis process was optimized in a way to determine the conditions required for obtaining significant bio‐char yield with maximum carbon content. The optimal conditions under N2 environment were identified to be 521°C, 48 min, 0.87 LPM and under CO2 environment were identified to be 545°C, 43 min and 0.87 LPM, respectively. The bio‐char produced under CO2 environment was observed to have higher porosity, surface area, pH and aromaticity. These results indicated that the bio‐char obtained under a reactive (CO2) environment could be used as a potential adsorbent. The bio‐char obtained under N2 environment was found to have higher carbon content and thus, could be utilized as soil conditioners or soil enhancers, to increase the soil fertility. [ABSTRACT FROM AUTHOR]

The present study concerns the application of nano-/micro-sized fibers (bio-char of Santa Maria feverfew) in cementitious mortars. The bio-char was added @ 0, 0.05 and 0.1% by mass of cement. The addition of bio-char did not affect the setting and consistency of the mortars. The fresh density was reduced by 11%, while the followability decreased by 50%. It is concluded that the bio-char results in a light-weight cementitious material, without affecting the setting time or consistency. Bio-char produces carbon-rich materials, the use of which as building materials adds to carbon sequestration in accordance with the Sustainable Development Goals of the UNO.

The untapped energy present in this cotton stalk residue is one of the major environmental threats due to its field burning. In this research paper, slow pyrolysis process has been performed on cotton stalk having particle size 0.85 mm at 300°C, 400°C, and 500°C, at 10°C/min heating rate and 1-hour residence time. The process produced bio-oil, bio-char and pyro-gas. Physiochemical properties, GC-MS analysis, stability analysis and miscibility analysis of bio-oil have been carried out to ensure its feasibility as energy source. To ensure suitability of bio-char as soil nutrient and energy sources, its elemental analysis, metal element analysis and microscopic examination have been performed. Pyro-gas is characterized to find its suitability as energy source for heating purpose during pyrolysis process by recirculating. The maximum yield for bio-oil and Pyro-gas is 36.60 wt.% and 25.25 wt.%, respectively at 500°C, while maximum yield for char is 58.54 wt. % at 300°C. Result of physiochemical properties of bio-oil reveals remarkable variation as compare to diesel whereas GC-MS analysis found bio-oil as complex mixture. 0.02349 cst/hr. aging rate of bio-oil shows good stability at room temperature. Physiochemical properties of bio-oil vary with pure diesel causes phase separation of bio-oil and diesel during blending. Bio-oil - diesel Stabilized emulsion has been achieved by addition of 6 wt. % of n-butanol as co-solvent. Characterization and microscopic examination of bio-char favours usage of char as soil nutrient and energy substitute. The Pyro-gas analysis confirms its suitability as energy substitute during entire process, as it contains a substantial amount of carbon dioxide and methane. [ABSTRACT FROM AUTHOR]

It is very important to produce carbonaceous porous material from sustainable biomass resource and to investigate its different application areas. In this study, it was aimed to use fir wood sawdust as catalyst support material in precious metal catalysts and to evaluate this catalyst in pyrolysis reactions of Brassica napus subsp. napus cake. Fir wood sawdust, which have high carbon and volatile matter content, was a suitable raw material for the production of bio-char by carbonization of biomass. 1%, 3% and 5% platinum (Pt) and palladium (Pd) metal loading was applied to fir wood sawdust biochar (FB) and the obtained catalysts were characterized. Among the different metal-loaded catalysts, the catalysts with the highest BET surface area are 5%Pd-FB and 1%Pd-FB catalysts. TEM images showed that as the amount of metal was increased, the particle size of Pd metal was also increased. ICP-OES results verified that the used impregnation method was more efficient and the standard deviation proportion was lower at low metal ratios. Pyrolysis experiments of B. napus subsp. napus were carried out in analytical pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) system with and without catalyst. Pyrolysis products was mixture of organic compounds in the range of C7–C29 carbons. With the application of catalytic pyrolysis, while the amount of alcohol, which was the desired product, was increased in the pyrolysis product, the amount of acid, which was the undesired product, was decreased. However, the amount of PAH, which was an undesirable product, increased with some catalyst applications, showed that bi-metallic catalyst applications can also be applied in future studies. Experimental results and discussions showed that the synthesis of carbon support material from biomass, which is a cheap and renewable resource, is a promising study. [ABSTRACT FROM AUTHOR]

The impact of the carbon nanomaterials (CNMs) wave in agro-application has been growing in recent years. The carbon nanomaterials family includes graphene oxide (GO), carbon nanotube (CNT), carbon nanofiber (CNF), carbon nanohorns (CNH), carbon nanodots (CND), carbon nano-onions (CNO), fullerene, and nano-diamond. The former seven belong to the sp2 carbon and the later belong to sp3 carbon. Based on the selection of the forms of allotropes, morphology, size, and the potential combination to form hybrids; the CNMs have shown different performance in the agro activities. Hence, in this review, all these studies along with our contributions are detailed briefly with the information about material synthesis, characterization, and application efficiency; the application includes the role in pesticide, fertilizer, and preservative sector. The review is finally concluded with the highlights about advantages, gaps/risks identified for the industry application, quality assurance status, and future perspectives. [Display omitted] [ABSTRACT FROM AUTHOR]

Pine saw dust as a typical forest residue is slowly pyrolyzed at 400–800 °C in a fixed bed system. The influence of pyrolysis temperature on the characteristics of bio-gas, bio-oil and bio-char is investigated and then to assess their potential uses. The result indicates that the yield of bio-gas increases as pyrolysis temperature increases, while the yield of bio-char decreases. The pyrolysis temperature does not have much effect on the yield of bio-oil. The bio-gas has high content of combustible gases (H2 + CO) and heating value with increase in pyrolysis temperature. The highest content of combustible gases is 76.96% with the highest heating value of 16.46 MJ/Nm3. The main identified compounds of bio-oil are the furfuran, alkane and phenol, respectively. Therefore, bio-oil can be used as the potential chemical materials in the food, chemical, pharmaceutical and other industries. The physiochemical properties of bio-char such as element content, and BET specific surface area have changed as pyrolysis temperature increases. Besides, bio-char could be potentially applied not only to remove Ag+ from aqueous solutions but also to produce a new value-added nanocomposite. [ABSTRACT FROM AUTHOR]

The agricultural economic policy of Cuba pretends to triplicate the crops of coffee and cocoa by 2021, a measure which will bring about both an increase in biomass waste and the need to find a proper method for its disposal. Slow pyrolysis process can transform lignocellulosic waste into added value products as biochar, bio-oil and gas. The present research evaluated the yield and the theoretical potential energy of co-products (biochar, bio-oil, and gas) from coffee and cocoa seed husks using the pyrolysis process as a source of friendly and renewable energy. Results indicated that coffee husks are more suitable for the production of gas with a yield of 40.4%, while cocoa seed husks are better suited for the production of bio-oil, with a yield of 37.4%. For 2021 the theoretical energy potential estimated is 8291 MWh, equivalent to 716000 kg for the coffee husks, and 1384 MWh equivalent to 121000 kg for the cocoa seed husks. The bio-char characterization indicated high contents of carbon, calcium, potassium, nitrogen, and oxygen, which makes it a suitable candidate for being used as a soil amendment. The conversion of coffee and cocoa seed husks into added value products through slow pyrolysis process will help clean the environment, decrease the greenhouse effect, and will aid farmers in the rural populations by providing them with an additional source of income.

This study proposes the conversion of waste corn grains contaminated by deoxynivalenol (also known as vomitoxin), a mycotoxin produced by plant pathogens, into a value-added product. Batches of 500 g of contaminated corn grains were pyrolyzed in a batch reactor by thermal treatment at temperatures up to 500°C with a 15°C/min heating rate and generating condensable vapors, gases and solid bio-char. The bio-char produced was subsequently activated in a furnace at 900°C, using CO2 as an activation agent, at different residence times. The effect of activation residence time on the characteristics of the activated bio-char, varying it from 0.5 to 3 h, was investigated. Characterization tests included BET surface area, SEM, TG-FTIR, pH, and XRD on both bio-char and activated bio-char. BET results illustrated a significant increase of the surface area from 63 to 419 m2g−1 and pore volume from 0.04 to 0.23 cm3g−1 by increasing the activation time from 0.5 to 3 h. SEM images visually confirmed a considerable increase in pore development. The pH significantly increased from 6 to 10 after activation, due to the elimination of acidic functional groups. The proximate analysis showed the stable carbon of the activated char reaching approximately 90 wt%, making it promising for catalyst/adsorbent applications. The adsorption performance of activated bio-char was tested by utilizing three different model molecules with different characteristics: methylene blue, methyl orange, and ibuprofen. Among all activated bio-char samples, activated bio-char with 3 h activation time showed the highest adsorption capacity, with a total adsorption (25 mg/g of activated bio-char) of methylene blue after 5 min. The results showed that the adsorption capacity of the activated bio-char was similar to that of valuable commercial activated carbon.

Solid-liquid phase change materials (PCMs) have been preferred for solar passive thermal energy storage (TES) applications. However, low thermal conductivity and leakage issue of molten PCMs considerably restrain their TES potential. In this framework, n-Heptadecane (HD) as a solid-liquid PCM was incorporated with carbonized lemon peel (CLP) for development of a novel leak-proof composite PCM. Chemical compatibility between the constituents of the leak-proof composite PCM was examined by using FTIR spectroscopy and XRD diffraction analyses. The DSC results revealed that the developed leak-proof CLP/HD composite PCM had a melting temperature of 19.79 °C and LHS capacity of 141.8 J/g. The composite PCM exposed venerable thermal degradation stability after a 1000-cycling heating-cooling process. Thermal conductivity of the CLP/HD composite PCM (0.46 W/m.K at 10 °C) was measured as approximately 77% higher than that of pristine HD (0.26 W/m.K at 10 °C). [Display omitted] • Carbonized biowaste lemon peel/heptadecane was developed as ecofriendly composite PCM. • Composite PCM had melting temperature of 19.79 °C and LHS enthalpy of 141.8 J/g. • Composite PCM had admirable cycling LHS reliability and thermal stability. • Composite PCM had 1.8 times thermal conductivity than higher than that of pure PCM. • Composite PCM is a promising additive for creating energy-saving building materials. [ABSTRACT FROM AUTHOR]

This study is focused on creating value addition to kitchen waste (KW) by converting it into valuable product resources via microwave pyrolysis. The effect of the following on product yields and energy efficiency were examined in this study: (i) microwave power (140–700 W), (ii) KW: susceptor ratio (20:0 to 20:20 (g/g)), and (iii) pyrolysis temperature (200–600 °C). The KW was pyrolyzed without the addition of a susceptor and char formed during pyrolysis acted as a susceptor and enhanced pyrolysis energy efficiency (78%). An increase in microwave power has significantly increased the heating rate from 4 to 85 °C/min, and KW has produced 73 wt% of bio-oil and gases even at low microwave power (140 W). An increase in pyrolysis temperature promoted thermal cracking of KW, which resulted in decreased char yields (64–27 wt%), and an increase in gas yields (12–45 wt%). Bio-oil contains a significant amount of phenolics (35–50%) and its selectivity varied significantly with the variables probed. The selectivity of furan derivatives has dramatically decreased from 45 to 20% with the increase in pyrolysis temperature. This work demonstrated the feasibility of valorization of kitchen waste into various value-added products. [Display omitted] s [ABSTRACT FROM AUTHOR]

In this study, a new method of microwave-induced discharge over biomass-derived char (i.e., bio-char) spherical carriers was proposed. Bio-char spherical carriers were obtained through rational forming. The discharge intensity and temperature increase under discharge were measured to elaborate the quantitative relationship between microwave discharge and the temperature increase. The effect of bio-char properties on microwave-induced discharge was investigated. The results revealed that discharge achieved the highest electric–thermal conversion efficiency of 61.04%, and the heat generation ratio through the discharge in the initial 10 min was up to 69.08%. The graphitisation degree and transmission depth of microwaves can affect discharge intensity. A critical light intensity inducing hot spot effect exists under different working conditions, and exceeding the critical value led to the hot spot effect and a sudden increase in bed temperature, with a corresponding range of 2.48–5.76 V. The maximum temperature under microwave discharge reached 981 °C, with a heating rate of 376.4 °C/min. The method is potential in the field of value-added utilization of bio-char and microwave-promoted chemical processes. [ABSTRACT FROM AUTHOR]