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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]

Bimetallic carbides, especially based on molybdenum carbide, proved to be a promising hydrodeoxygenation (HDO) catalyst, with enhanced selectivity towards C─O bonds cleavage. However, catalysts are generally investigated using limited model components derived from only one of the biopolymers in biomass (either lignin or carbohydrates), therefore, HDO of raw biomass‐derived bio‐oil still remains a challenge, as it contains molecules of different functionalities. This paper presents a systematic comparison of the monometallic carbide, Mo2C, with the novel bimetallic carbide incorporating W using representative bio‐oil components of different functionalities and derived from different bio‐polymers components of biomass. We employed quantum mechanical investigation to reveal that the W‐doped Mo2C carbide (MoWC) catalyst with increased oxophilicity, owing to tungsten incorporation, can perform HDO of real bio‐oil more effectively in comparison to its monometallic counterpart (Mo2C) using six substrates representing different components of bio‐oil. We showed MoWC can selectively cleave both single/double (C─O/C═O) bonds with similar barriers in comparison to Mo2C which can only selectively cleave single C─O bonds. This observation was consistent for 5‐HMF, Acetic acid, and Methyl Glyoxal. We also showed that MoWC outperforms its metallic counterpart Mo2C in the HDO for aromatic and carbohydrates components. [ABSTRACT FROM AUTHOR]

The creation of hydrogen using the lower‐cost feedstock, waste organics (WOs), e. g. kitchen waste bio‐oil, is a win‐win solution, because it can both solve energy problems and reduce environmental pollution. Ultrasound has received considerable interest in organic decomposition; however, the application of ultrasound alone is not a good choice for the hydrogen production from WOs, because of the energy consumption and efficiency. To boost the hydrogen production based on ultrasonic cavitation cracking of bio‐oil, photothermal materials are introduced into the hydrogen production system to form localized hot spots. Materials carbon black (CB), carbon nanotubes (CNT), and silicon dioxide (SiO2) all exhibit significant enhancing effects on the hydrogen production from bio‐oil, and the CB exhibits the most significant strengthening effect among these materials. When the dosage of CB is 5 mg, hydrogen production rate is 180.1 μmol h−1, representing a notable 1.7‐fold increase compared to the production rate without CB. In the presence of light and ultrasound, the hydrogen production rate can be increased by 66.7‐fold compared to the situation where only light is present without ultrasound. [ABSTRACT FROM AUTHOR]

In the energy transition process, aiming for zero disposal and clean production in the elimination of waste is crucial; consequently, agricultural residues have significant potential for reduction in the use of fossil fuels. This study investigates the hydrothermal liquefaction (HTL) of sugarcane bagasse (BSC) and straw (SSC), examining the products' distribution and bio-oil composition relative to the reaction conditions. The experiments used a 23 factorial design, evaluating the temperature (300–350 °C), constant heating time (0–30 min), and the use of the K2CO3 concentration as the catalyst (0–0.5 mol/L−1). The main factor affecting the biocrude yield from BSC and SSC was the use of K2CO3. Statistically significant interaction effects were also observed. Milder conditions resulted in the highest bio-oil yields, 36% for BSC and 31% for SSC. The catalyst had no impact on the biocrude production. The bio-oils were analyzed by GC/MS and FTIR; a principal component analysis (PCA) was performed to evaluate the samples' variability. The FTIR highlighted bands associated with common oxygenated compounds in lignocellulosic biomass-derived bio-oils. The GC-MS results indicated a predominance of oxygenated compounds, and these were highest in the presence of the catalyst for both the BSC (90.6%) and SSC (91.7%) bio-oils. The SSC bio-oils presented higher oxygenated compound contents than the BSC bio-oils. Statistical analysis provided valuable insights for optimizing biomass conversion processes, such as determining the optimal conditions for maximizing product yields. [ABSTRACT FROM AUTHOR]

Biomass, as a renewable and clean energy source, can be utilized for partial fuel substitution through the process of fast pyrolysis, which converts it into bio-oil. However, the presence of naturally occurring metallic elements in biomass has an adverse effect on its pyrolysis process. In this study, the aqueous fraction separated from biomass pyrolysis liquid, characterized by its acidity and high water content, was used for washing pretreatment of walnut shells. The analysis of the treated walnut shells was meticulously conducted employing techniques, including inductively coupled plasma mass spectrometry, thermogravimetric analyzer, and pyrolyzer-gas chromatography/mass spectrometer. The results indicate that this method has a positive influence on the composition and structure of walnut shells, with removal rates of 75% for Na and 45% for K. The thermal decomposition peak on the thermogravimetric curve became more distinct and shifted to higher temperatures. In additionally, the maximum weight loss rate increases to 0.83 °C/%, and the final residue decreased to 17%. The yields of acids and ketones in the pyrolysis products decreased by 49.43% and 53.69%, respectively. Meanwhile, the yields of phenols and sugars increased by 17.43% and 80%, respectively. Furthermore, the influence of pyrolysis conditions (temperature and time) on the pyrolysis products was investigated, and the optimal pyrolysis conditions (500 °C and 20 s) were determined. Therefore, washing pretreatment of the aqueous part of pyrolysis liquid can effectively enhance the quality of biomass and pyrolysis products. It not only contributes to improving the utilization value of pyrolysis liquid by-product but also holds practical significance for the sustainable use of resources and energy production. [ABSTRACT FROM AUTHOR]

The study determines the frequency–temperature dependence of the conductivity of a moist solid insulation component of power transformers, impregnated with the innovative bio-oil NYTRO® BIO 300X, manufactured from plant-based raw materials. The research was conducted for six moisture levels ranging from 0.6% to 5% by weight, within a frequency range from 10−4 Hz to 5 · 103 Hz and measurement temperatures from 20 °C to 70 °C, with a 10 °C step. The conduction model for both DC and AC, based on the quantum mechanical phenomenon of electron tunneling between water nanodroplets, was used to analyze the obtained results. It was determined that the frequency dependence of the conductivity of pressboard-bio-oil-moisture composites is influenced by two factors as follows: the activation energy of conductivity and the activation energy of relaxation time. For each moisture content, 16 values of the activation energy of the relaxation time and 16 values of the activation energy of conductivity were determined. It was found that the values of activation energy of conductivity and relaxation time are equal and independent of moisture content, frequency, and temperature. Based on 192 residual activation energy values, the mean generalized activation energy value for the relaxation time and conductivity was calculated with high precision, resulting in ΔE ≈ (1.02627 ± 0.01606) eV. The uncertainty of its determination was only ±1.6%. This indicates that electron tunneling from the first nanodroplet to the second, causing AC conductivity, and their return from the second nanodroplet to the first, determining the relaxation time, occur between the same energy states belonging to the water nanodroplets located in the pressboard impregnated with bio-oil. For each moisture content, the curves obtained for different measurement temperatures were recalculated to a reference temperature of 20 °C using the generalized activation energy. It was found that the shifted curves obtained for different temperatures perfectly overlap. Increased moisture content shifts the recalculated curves toward higher conductivity values. It was established that for all moisture contents in the lowest frequency range, conductivity is constant (DC conductivity). A further increase in frequency causes a rapid rise in conductivity. The increasing period can be divided into two stages. The first stage occurs up to about 100 Hz–101 Hz, depending on the moisture content. In the second stage, the rate of conductivity increase is higher, and its value depends on moisture content. The lower the moisture content, the faster the conductivity increases. Recalculation using the generalized activation energy eliminated the effect of temperature on the curves. It was found that the shapes of the recalculated curves and their position relative to the coordinates depend only on the moisture content in the composite. The equality of the activation energy of the relaxation time and conductivity established in the study, as well as their independence from frequency and moisture content in the pressboard impregnated with NYTRO® BIO 300X bio-oil, allows for recalculating the curves of electrical parameters determined at any operating temperatures of the transformer to a reference temperature, for example, 20 °C. Comparing the curve obtained for the transformer, recalculated to the reference temperature, with reference curves determined by us in the laboratory for different moisture contents, will allow for the precise determination of the moisture content of the solid insulation component impregnated with NYTRO® BIO 300X bio-oil. This will contribute to the early detection of approaching critical moisture content, threatening catastrophic transformer failure. [ABSTRACT FROM AUTHOR]

Pyrolysis is an environmentally friendly and efficient method for converting biomass into a wide range of products, including fuels, chemicals, fertilizers, catalysts, and sorption materials. This review confirms that scientific research on biomass pyrolysis has remained strong over the past 10 years. The authors examine the operating conditions of different types of pyrolysis, including slow, intermediate, fast, and flash, highlighting the distinct heating rates for each. Furthermore, biomass pyrolysis reactors are categorized into four groups, pneumatic bed reactors, gravity reactors, stationary bed reactors, and mechanical reactors, with a discussion on each type. The review then focuses on recent advancements in pyrolysis technologies that have improved efficiency, yield, and product quality, which, in turn, support sustainable energy production and effective waste management. The composition and yields of products from the different types of pyrolysis have been also reviewed. Finally, a techno-economic analysis has been conducted for both the pyrolysis of biomass alone and the co-pyrolysis of biomass with other raw materials. [ABSTRACT FROM AUTHOR]

As global energy demands rise and non-renewable resources decrease, identifying sustainable alternatives is of utmost importance. This study investigates the potential of Carica papaya seeds as a feedstock for bio-oil production. Employing the central composite design of response surface methodology, the extraction process was optimized using heptane as the solvent. The effects of biomass to heptane ratio and extraction time on oil yield were examined. The optimized conditions of 1:11 biomass to heptane ratio (g:mL) and 4-h extraction time yielded an optimal oil yield of 45.77±0.057%. The chemical composition analysis revealed a kinematic viscosity of 12.58 mm2/s at 40°C, indicating favorable flow properties, and a high heating value of 37.52 MJ/kg, suggesting its energy potential. Fourier transform infrared (FTIR) analysis detected carbonyl functional groups and alkanes, indicating the suitability of Carica papaya seed oil for biodiesel production. These findings highlight the promising role of Carica papaya seeds as a renewable feedstock for bio-oil, contributing to sustainable energy development. This research addresses the pressing challenge of depleting non-renewable resources and underscores the significance of Carica papaya seeds as a valuable and eco-friendly source for bio-oil production. Such advancements pave the way for a greener and more sustainable energy future. [ABSTRACT FROM AUTHOR]

Investigation of Lantana camara biomass for potential bioenergy generation integrates invasive species (IS) management with the unabated demand for bio-energy. In the present investigation, L. camara was used to produce bio-oil by thermochemical conversion (pyrolysis). The resultant product evinced energy yield of 62.58% with 64.95% of elemental carbon (C) content and endorsed the suitability of L. camara bio-oil for biofuel applications and value addition. Thermogravimetric (TG-DTG) analysis revealed a short thermal degradation profile, whereas spectroscopic analyses detected a host of organic compounds such as esters, phenols, ketones, aldehydes, aliphatics, and aromatics. The economic analysis of L. camara biomass conversion technology carried out in this study proved to be commercially competitive and viable versus petroleum refining. Antimicrobial and antioxidant assays with bio-oil evinced highest zone of inhibition (ZOI) against Candida albicans (31.02 mm), and displayed strong antioxidant property (DPPH IC50 value 233.72 ± 0.2 μg/ml). The bio-oil exhibited rheological characteristics of shear thinning and pseudoplastic fluid, particularly at low and intermediate shear rates. The present study highlights the multifaceted advantages of utilizing L. camara biomass, which include environmental remediation via waste management, bioenergy generation, and the feasibility of generating value-added products. [ABSTRACT FROM AUTHOR]

In this study, slow pyrolysis of the camelthorn plant process was conducted to produce bio-oil, biochar, and gas. The pyrolysis process was conducted between 400 and 550 °C under pressure 10 bar using a fixed bed reactor. The pyrolysis products were bio-oil, biogas, and biochar. These products were characterized using Fourier-transform infrared (FT-IR) model, gas analyzer, chromatographic analysis using GC–MS, and thermogravimetric analysis (TGA). The GC–MS results demonstrated composition of bio-oil, detecting several organic substances including levoglucosan, furan, acetic acid, phenol, and long-chain hydrocarbon. To further understand the chemical composition of bio-oil, FT-IR spectroscopy was conducted to determine functional groups. The thermal behavior and degradation of the camelthorn sample were studied using TGA which provided thermal stability and prospective applications. Gas composition was measured using a gas analyzer. These analytical methods' results offer insight on the camelthorn plant's potential as a sustainable bio-oil and biochar sources, and these findings contribute to the advancement of biomass conversion expertise and provide vital insights for sustainable energy production. [ABSTRACT FROM AUTHOR]

Bio-oil produced via fast pyrolysis, irrespective of the biomass source, faces several limitations, such as high water content, significant oxygenated compound concentration (35–40 wt.%), a low heating value (13–20 MJ/kg), and poor miscibility with fossil fuels. These inherent drawbacks hinder the bio-oil's desirable properties and usability, highlighting the necessity for advanced processing techniques to overcome these challenges and improve the bio-oil's overall quality and applicability in energy and industrial sectors. To address the limitations of bio-oil, a magnetic bimetallic oxide catalyst supported on activated rice straw biochar (ZrO2-Fe3O4/AcB), which has not been previously employed for this purpose, was developed and characterized for upgrading rice straw bio-oil in supercritical butanol via esterification. Furthermore, the silica in the biochar, combined with the Lewis acid sites provided by ZrO2 and Fe3O4, offers Brønsted acid sites. This synergistic combination enhances the bio-oil's quality by facilitating esterification, deoxygenation, and mild hydrogenation, thereby reducing oxygen content and increasing carbon and hydrogen levels. The effects of variables, including time, temperature, and catalyst load, were optimized using response surface methodology (RSM). The optimal reaction conditions were determined using a three-factor, one-response, and three-level Box-Behnken design (BBD). The ANOVA results at a 95% confidence level indicate that the results are statistically significant due to a high Fisher's test (F-value = 37.07) and a low probability (p-value = 0.001). The minimal difference between the predicted R² and adjusted R² for the ester yield (0.0092) suggests a better fit. The results confirm that the optimal reaction conditions are a catalyst concentration of 1.8 g, a reaction time of 2 h, and a reaction temperature of 300 °C. Additionally, the catalyst can be easily recycled for four reaction cycles. Moreover, the catalyst demonstrated remarkable reusability, maintaining its activity through four consecutive reaction cycles. Its magnetic properties allow for easy separation from the reaction mixture using an external magnet. [ABSTRACT FROM AUTHOR]

This study is focused on the modelling of the production of bio-oil by thermochemical liquefaction. Species Acacia melanoxylon was used as the source of biomass, the standard chemical 2-Ethylhexanol (2-EHEX) was used as solvent, p-Toluenesulfonic acid (pTSA) was used as the catalyst, and acetone was used for the washing process. This procedure consisted of a moderate acid-catalysed liquefaction process and was applied at 3 different temperatures to determine the proper model: 100, 135, and 170 °C, and at 30-, 115-, and 200-min periods with 0.5%, 5.25%, and 10% (m/m) catalyst concentrations of overall mass. Optimized results showed a bio-oil yield of 83.29% and an HHV of 34.31 MJ/kg. A central composite face-centred (CCF) design was applied to the liquefaction reaction optimization. Reaction time, reaction temperature, as well as catalyst concentration, were chosen as independent variables. The resulting model exhibited very good results, with a highly adjusted R-squared (1.000). The liquefied products and biochar samples were characterized by Fourier-transformed infrared (FTIR) and thermogravimetric analysis (TGA); scanning electron microscopy (SEM) was also performed. The results show that invasive species such as acacia may have very good potential to generate biofuels and utilize lignocellulosic biomass in different ways. Additionally, using acacia as feedstock for bio-oil liquefaction will allow the valorisation of woody biomass and prevent forest fires as well. Besides, this process may provide a chance to control the invasive species in the forests, reduce the effect of forest fires, and produce bio-oil as a renewable energy. [ABSTRACT FROM AUTHOR]

Hydrothermal liquefaction technology (HTL) is a promising thermochemical method to convert biomass into novel liquid fuels. The introduction of oxides and inorganic acids/bases during the hydrothermal process significantly impacts the yield and composition of bio-oil. However, systematic research on their effects, especially at lower temperatures, remains limited. In this paper, we examine the effects of acidity and alkalinity on cotton stalk hydrothermal bio-oil by introducing homogeneous acids and bases. Given the operational challenges associated with product separation using homogeneous acids and bases, this paper further delves into the influence of heterogeneous oxide catalysts (possessing varying degrees of acidity and alkalinity, as well as distinct microstructures and pore architectures) on the production of cotton stalk hydrothermal bio-oil. The effects of nanoscale oxides (CeO2, TiO2, ZnO, Al2O3, MgO and SiO2) and homogeneous acid–base catalysts (NaOH, K2CO3, Na2CO3, KOH, HCl, H2SO4, HNO3) on the quality of cotton stalk bio-oil under moderate hydrothermal conditions (220 °C, 4 h) were investigated. Characterization techniques including infrared spectroscopy, thermogravimetric analysis, elemental analysis, and GC-MS were employed. The results revealed that CeO2 and NaOH achieved the highest bio-oil yield due to Ce3+/Ce4+ redox reactions, OH-LCC disruption, and ionic swelling effects. Nano-oxides enhanced the formation of compounds like N-ethyl formamide and aliphatic aldehydes while suppressing nitrogen-containing aromatics. The total pore volume and average pore width of oxides negatively correlated with their catalytic efficiency. CeO2 with low pore volume and width exhibited the highest energy recovery. The energy recovery of cotton stalk bio-oil was influenced by both acid and base sites on the oxide surface, with a higher weak base content favoring higher yields and a higher weak acid content inhibiting them. The findings of this research are expected to provide valuable insights into the energy utilization of agricultural solid waste, such as cotton stalks, as well as to inform the design and development of highly efficient catalysts. [ABSTRACT FROM AUTHOR]

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Biomass pyrolysis is the most effective process to convert abundant organic matter into value-added products that could be an alternative to depleting fossil fuels. A comprehensive understanding of the biomass pyrolysis is essential in designing the experiments. However, pyrolysis is a complex process dependent on multiple feedstock characteristics, such as biomass consisting of volatile matter, moisture content, fixed carbon, and ash content, all of which can influence yield formation. On top of that, product composition can also be affected by the particle size, shape, susceptors used, and pre-treatment conditions of the feedstock. Compared to conventional pyrolysis, microwave-assisted pyrolysis (MAP) is a novel thermochemical process that improves internal heat transfer. MAP experiments complicate the operation due to additional governing factors (i.e. operating parameters) such as heating rate, temperature, and microwave power. In most instances, a single parameter or the interaction of parameters, i.e. the influence of other parameter integration, plays a crucial role in pyrolysis. Although various studies on a few operating parameters or feedstock characteristics have been discussed in the literature, a comprehensive review still needs to be provided. Consequently, this review paper deconstructed biomass and its sources, including microwave-assisted pyrolysis, and discussed the impact of operating parameters and biomass properties on pyrolysis products. This paper addresses the challenge of handling multivariate problems in MAP and delivers solutions by application of the machine learning technique to minimise experimental effort. Techno-economic analysis of the biomass pyrolysis process and suggestions for future research are also discussed. [ABSTRACT FROM AUTHOR]

Plastic waste is a rich source of hydrocarbons that can be converted into bio-oil through pyrolysis. In this study, bio-oil was produced by pyrolysis of waste-polypropylene using spent FCC catalyst. Gas chromatography-mass spectrometry (GC–MS) analysis revealed that catalytically produced oil has the majority of compounds in the hydrocarbon range of C6–C18. The catalytic pyrolysis oil was blended with conventional fuel (diesel) to extensively investigate its suitability as a fuel substitute in a single-cylinder, four-stroke, 3.5 kW, diesel internal combustion (IC) engine. Furthermore, four fuels, i.e., CF100PO00 (pure diesel), CF90PO10 (10% v/v pyrolysis oil blended with diesel), CF85PO15 (15% v/v pyrolysis oil blended with diesel), and CF80PO20 (20% v/v pyrolysis oil blended with diesel), were tested in IC diesel engine for performance, combustion, and exhaust emission analysis at 1500 rpm. The tests were carried out at five loads, i.e., 1, 5, 10, 15, and 20 Nm. It was found that CF90PO10 produced 6.61% higher brake thermal efficiency (BTE), whereas CO2 exhaust emission decreased by 20% for CF80PO20 with respect to the pure diesel. Diesel blends with plastic pyrolysis oil can be a promising biofuel to improve engine performance and combustion characteristics without any significant engine modification. [ABSTRACT FROM AUTHOR]

This study deals with the solid waste management in tea processing industries by thermochemical conversion of the raw or industrial tea waste (ITW) for bioenergy generation and value addition. The elemental carbon (C) in ITW was 43.35%. Moreover, ITW exhibited gross calorific value (GCV) of 43.35% and 19.48 MJ/kg, which was comparable to firewood species. ITW was subjected to pyrolysis and industrial tea waste biochar (ITWBC) and industrial tea waste bio-oil (ITWB) were obtained as the main products. The pyrolysis increased the elemental C content and GCV in ITWBC up to 80.01 wt% and 24.00 MJ kg−1, respectively. Besides, alkane, alcohol, phenol, nitro, and aromatic compounds were obtained during spectroscopic analysis of ITWBC. The fixed carbon (FC) content increased from 22.50 to 74% after the conversion of ITW to ITWBC. The H/C and O/C ratios (in weight) decreased after the thermochemical conversion of ITW to ITWBC and ITWB. ITWB is comprised of 66.21% of C; the major components were phenolic (84.6%). Moreover, aromatics, esters, ethers, ketones, alcohols, furans, and aliphatic components were also identified during spectroscopic analysis of the ITWB. The spectroscopic analyses suggest effective thermochemical conversion of ITW with the involvement of chemical processes such as polymerization, dehydration, decarboxylation, aromatization, intermolecular condensations, and rearrangements. The study highlights the possibility of waste management in tea industries via integrated biorefinery approach, besides further validating the potential of ITW for energy/fuel production and value-added product development under the realm of "Waste to Wealth" technology. [ABSTRACT FROM AUTHOR]

In this study, the effect of pressurized torrefaction both by gas-pressurized (GP) and mechanical pressure (MP) at 250 °C on the properties of bio-oil was investigated. GP torrefaction enhanced the deoxygenation reactions and resulted in low O/C atomic ratio of torrefied biomass. The GP torrefaction at 4 MPa (GP-4.0) could remove oxygen content by 46.0%. Acids content in bio-oil for GP-4.0 were reduced to 3.6%, while phenols content increased to 46.7%. However, the yield of bio-oil was only 30.5% for GP-4.0. In contrast, MP torrefaction promoted the cross-linking reactions. The combination of MP torrefaction at 40 MPa and pyrolysis at 250 °C for 30 min (MP-40–30) could remove the oxygen content by 28.2%. The yield of bio-oil was as high as 44.7% for MP-40–30. Acids and furans content in bio-oil decreased, while alcohols, phenols, and hydrocarbons content in bio-oil increased for MP-40–30. Moreover, the hydrocarbons content in bio-oil increased to 11.9% for MP-40–30. Results from this study provided necessary information needed for developing the pyrolysis polygeneration from pressurized torrefied biomass. [ABSTRACT FROM AUTHOR]

A thermodynamic analysis was performed for the production of synthesis gas and hydrogen gas from steam reforming of propionic acid, one of the constituents of the bio-oil, using ASPEN Plus v8.8. The aim of the study was to perform a global analysis on steam reforming of propionic acid focusing on several parameters such as steam-to-propionic acid ratio, reaction temperature, addition of O 2 in the feed stream and presence of CaO as a CO 2 sorbent in the reaction environment. The results showed that higher amounts of steam/propionic acid ratio resulted in higher H 2 and CO 2 yields. It was also observed that high H 2 O/PA molar ratios led to reduced coke production as WGS reaction was favored with excess steam, causing CO in the reaction mixture to be consumed through the WGS reaction rather than the Boudouard reaction. Addition of O 2 in the reaction environment was observed to negatively affect yield of H 2. Yet, coke formation was deprived and increasing the O 2 amount in the feed stream decreased the energy required for the process. Furthermore, the presence of CaO enhanced H 2 yield and energy requirements of the process compared to conventional steam reforming process. 100 % yield of H 2 production with a heat generation of −83.4 MJ/kmol of PA and almost zero formation of CO 2 , CO, CH 4 and coke is achieved at 600 °C for sorption enhanced steam reforming of propionic acid. [Display omitted] • Maximum H 2 production is noted as 4.96 kmol/kmol of PA at 750 °C for H 2 O/PA = 4. • O 2 /PA molar ratio significantly affect the heat requirement & coke deposition. • Process enthalpy changes from 38.5 to −49.5 & −83.4 MJ/kmol with higher CaO. • 100% H 2 yield is achieved for CaO = 3 kmol/h at 600 and 700 °C. [ABSTRACT FROM AUTHOR]

Alternative biomass for energy can reduce fossil fuel use and environmental impacts, providing energy security in semi-arid areas with shallow soils that are not ideal for agro-forestry. The densification of sorghum biomass (SB) brings its energetic characteristics closer those of wood. Higher heating value (HHV) represents the heat produced by a given quantity of fuel. This Brazilian research tested different mixtures of SB, eucalyptus wood (W), and eucalyptus bio-oil (Bo) as briquettes for HHV and least ash. Compressed mixtures of SB+B were compared to W+Bo and SB+W+Bo. The concentrations of bio-oil added to SB/W were 1%, 3%, 4%, and 5%. SB+W+Bo composites' W content was 0%, 25%, 50%, 75%, and 100%, with Bo as 3% of the weight. Sorghum biomass' HHV is equivalent to W at 3%Bo. Bo doses of 4% and 5% had the same HHV as 3%. Eucalyptus wood did not have a significantly greater HHV with any amount of Bo. SB+W+3%Bo had the same HHV as W when W was at least 50% of the mixture. At greater than 36%W, the ash content was lower than 3%, meeting the EN-B international standard. The optimal composite mixture was 64%SB+36%W+3%Bo for HHV and ash content. SB briquettes can be more widely adopted given sorghum's prevalence in semi-arid environments. [ABSTRACT FROM AUTHOR]

In response to the increasing global demand for sustainable energy alternatives, this research explores the efficient conversion of sugarcane bagasse to bio-oil through hydrothermal liquefaction (HTL) processes with modified Zeolite Socony Mobil-5 catalysts (ZSM-5). The study systematically investigates the impact of feedstock quantity, reaction temperature, duration, and catalyst loading on bio-oil yield and quality. Optimisation experiments revealed that a feedstock amount of 10 grammes, an HTL temperature of 340 °C for 60 min and a ZSM-5 catalyst loading of 3 grammes resulted in the highest bio-oil yield. Furthermore, the introduction of Ni and Fe metals to ZSM-5 exhibited enhanced catalytic activity without compromising the structure of the zeolites. Comprehensive characterisation of modified catalysts using SEM-EDS, XRD, TGA, TEM, and FTIR provided insight into their structural and chemical properties. The successful incorporation of Ni and Fe into ZSM-5 was confirmed, highlighting promising applications in hydrothermal liquefaction. Gas chromatography–mass spectrometry (GC-MS) analysis of bio-oils demonstrated the effectiveness of the 2% Fe/ZSM-5 catalyst, highlighting a significant increase in hydrocarbon content. FTIR analysis of the produced bio-oils indicated a reduction in functional groups and intensified aromatic peaks, suggesting a shift in chemical composition favouring aromatic hydrocarbons. This study provides valuable information on HTL optimisation, catalyst modification, and bio-oil characterisation, advancing the understanding of sustainable biofuel production. The findings underscore the catalytic prowess of modified ZSM-5, particularly with iron incorporation, in promoting the formation of valuable hydrocarbons during hydrothermal liquefaction. [ABSTRACT FROM AUTHOR]

Bio-oil combined steam/dry reforming (CSDR) with H2O and CO2 as reactants is an attractive route for the joint valorization of CO2 and biomass towards the sustainable production of syngas (H2 + CO). The technological development of the process requires the use of an active and stable catalyst, but also special attention should be paid to its regeneration capacity due to the unavoidable and quite rapid catalyst deactivation in the reforming of bio-oil. In this work, a commercial Rh/ZDC (zirconium-doped ceria) catalyst was tested for reaction–regeneration cycles in the bio-oil CSDR in a fluidized bed reactor, which is beneficial for attaining an isothermal operation and, moreover, minimizes catalyst deactivation by coke deposition compared to a fixed-bed reactor. The fresh, spent, and regenerated catalysts were characterized using either N2 physisorption, H2-TPR, TPO, SEM, TEM, or XRD. The Rh/ZDC catalyst is initially highly active for the syngas production (yield of 77% and H2/CO ratio of 1.2) and for valorizing CO2 (conversion of 22%) at 700 °C, with space time of 0.125 gcatalyst h (goxygenates)−1 and CO2/H2O/C ratio of 0.6/0.5/1. The catalyst activity evolves in different periods that evidence a selective deactivation of the catalyst for the reforming reactions of the different compounds, with the CH4 reforming reactions (with both steam and CO2) being more rapidly affected by catalyst deactivation than the reforming of hydrocarbons or oxygenates. After regeneration, the catalyst's textural properties are not completely restored and there is a change in the Rh–support interaction that irreversibly deactivates the catalyst for the CH4 reforming reactions (both SR and DR). As a result, the coke formed over the regenerated catalyst is different from that over the fresh catalyst, being an amorphous mass (of probably turbostractic nature) that encapsulates the catalyst and causes rapid deactivation. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the storage stability and rheological property of bio-oil/lignin composite-modified asphalt. The composite-modified asphalt with different proportions of bio-oil was prepared and cured at 105 °C, 135 °C, and 165 °C for 24 h and 48 h. The storage stability of the composite-modified asphalt was evaluated based on the softening point difference, the storage stability index derived from rotational viscosity, the segregation rate based on temperature sweep, and the non-recoverable creep compliance measured through the Multiple Stress Creep Recovery test. The storage stability of bio-oil/lignin composite-modified asphalt was evaluated through testing and analysis of its infrared spectroscopy and scanning electron microscopy before and after thermal storage. The research results indicate that the maximum difference in softening point is 0.9 °C, and the calculated storage stability index is generally below 0.1. The maximum value of the segregation rate is 0.43, indicating excellent storage stability of the bio-oil/lignin composite-modified asphalt. According to the results from infrared spectroscopy, no chemical reactions occurred during the storage process of the composite-modified asphalt. The scanning electron microscope confirmed that the samples became more stable after 48 h of storage. [ABSTRACT FROM AUTHOR]

The ecologically friendly disposal of arsenic-enriched plants is the key link to achieve the industrial development of phytoremediation, and plays a restricting role in the high-quality development of soil heavy metal pollution control. Conventional treatment methods of hyperaccumulators mainly include incineration and landfill, but these methods may lead to secondary pollution of heavy metals. Hydrothermal liquefaction can transform agricultural and forestry waste with low energy density into liquid biofuel with high energy density. It has the advantages of low reaction temperature, low energy consumption, water as solvent and no need for drying as raw material. As a typical representative of arsenic contaminated soil phytoremediation, the effects of ethanol ratio and water cycle times on hydrothermal oil production and heavy metal arsenic distribution of centipede grass were investigated in this study using Pteris vittata L. as raw material and ethanol-water reaction co-solvent system. The results showed that under the conditions of 60% ethanol concentration and 3 cycles of aqueous phase, the highest yield of liquefied bio-oil was 51.08%, and its calorific value was 29.15 MJ/kg. The reasons for the increase of biooil after water phase circulation in the co-solvent system are as follows: 1) the organic acids (acetic acid, etc.) in the recycled water phase have an acid catalytic effect to promote biomass liquefaction; 2) Compared with pure water, ethanol in cosolvent has lower liquefaction critical point and dielectric constant, which promotes biomass degradation and hydrolysis; 3) Ethanol can esterify the acid in the aqueous phase to improve the yield of bio-oil. Bio-oil is mainly composed of esters (>80%), phenols, alcohols, ketones, hydrocarbons, etc. With the increase of water cycle times, the esters and phenols in bio-oil increased and the high boiling point compounds decreased, the bio-oil yield and energy recovery increased by 58% and 32.23%, respectively. This may be affected by esterification of ethanol with fatty acids. Moreover, aqueous cycle can promote the degradation of high boiling point compounds to low boiling point compounds, which may be related to the low boiling point compounds produced after the reuse of liquefied water phase with the addition of 60% ethanol-water cosolvent. After water phase circulation, the content of bio-oil distillate (boiling point <538 ℃) increased from 65.57% to 71.70%, which show that ethanol-water co-solvent can produce high quality bio-oil in aqueous phase recycling. Finally, the migration and transformation of arsenic in enriched plants during liquefaction were also investigated. After aqueous phase circulation, more than 80% of heavy metal arsenic was mainly distributed in the water phase and the concentration of arsenic increased to 215.05 mg/kg. The enrichment and removal of arsenic during liquefaction plays an important role in the post-disposal of arsenic-enriched plants, which greatly reduces the secondary pollution of heavy metals. Therefore, water phase recycling is an effective way to obtain high-yield bio-oil and arsenic enrichment from liquefaction disposal of arsenic-enriched plants, which provides a new idea for ecologically friendly disposal of arsenic-enriched plants, promotes the industrial development of phytoremediation, and speeds up the treatment of soil heavy metal pollution. To provide theoretical support for green, low-carbon and new quality development in the process of heavy metal pollution control in our country. [ABSTRACT FROM AUTHOR]

Interest has emerged recently in addressing the long‐standing issue of waste plastic disposal and environmental challenges through the co‐liquefaction of waste plastics with eco‐friendly renewable biomass resources, including microalgae biomass and lignocellulosic biomass, to produce biofuels. Co‐liquefaction provides a viable alternative for managing plastic waste while contributing to biofuel production. The purpose of this article is to provide a comprehensive review of the advances in the co‐liquefaction of various mixtures of plastic waste and different types of biomass feedstocks (lignocellulosic and algal) for the production of biofuels. The influence of various reaction parameters, such as feedstock composition (blending ratio), temperature, catalyst type and loading, solvents, and reaction time on the product yield are explored. The synergistic interaction during the co‐liquefaction of biomass and plastic and the distribution and properties of biofuel products are also discussed. The findings demonstrate that maximum product yields vary depending on the final temperature, and the blending ratio plays a crucial role in determining the distribution of liquefaction products. Of particular interest is biocrude oil, the components of which are influenced by the composition of the feedstock material. The distribution of organic elements in the biochar is contingent upon the type of plastic used. Although the analysis of gas‐phase components is often overlooked, the reaction medium's composition is shown to impact the resulting gas composition. Finally, based on the insights gleaned from the literature, this review presents future perspectives on the subject matter. In general, the co‐liquefaction process offers a viable option for sustainable biofuel production and is a promising approach to address the waste plastics disposal challenges effectively, contributing to the valorization of plastic waste to achieve a circular bioeconomy in the future. [ABSTRACT FROM AUTHOR]

In this study, biochars with different structures were prepared through HNO3 oxidation and secondary pyrolysis to study the relationship between the structure of biochar and its selectivity for the adsorption of light and heavy aromatics in bio‐oil. The results showed that the adsorption rates of biochar with different structures ranged from 2.90 to 4.00 g bio‐oil per g biochar. The influence of pore structure was dominant, followed by the influence of O‐containing functional groups and the degree of graphitization. The higher the adsorption capacity of biochar for bio‐oil, the smaller the concentrations of the light aromatic model compounds in the absorbed bio‐oil (ABO). Among the five light aromatics, biochar has the best adsorption selectivity for dihydroxybiphenyl and the worst for eugenol and propyl phenol. This is attributed to the diphenyl ring structure of dihydroxybiphenyl, which makes it more susceptible to adsorption, and other light model compounds only have one benzene ring. In summary, biochar demonstrates better adsorption selectivity for heavy aromatics than light aromatics. The more developed the pore structure is, the more enriched O‐containing functional groups are, and the higher the graphitization degree of biochar is, the better the selective adsorption of aromatic compounds in bio‐oil. [ABSTRACT FROM AUTHOR]

Bio-oil obtained through the gasification or pyrolysis of biomass is a renewable energy source with the potential to be used in motor vehicles. However, when the properties of bio-oil are compared to crude oil, bio-oil is observed to have high oxygen content and acidity. The aim of this study is to enhance the physical properties of bio-oil and produce new alternative fuels to crude oil. For this purpose, nickel and cobalt-incorporated mesoporous HZSM-5 catalysts have been synthesized. The synthesized catalysts were characterized by X-ray diffraction, N2 adsorption–desorption, Scanning electron microscopy energy dispersive spectroscopy, Inductively coupled plasma optical emission spectroscopy, Fourier-transformed infrared spectroscopy, and thermogravimetric/differential thermal analysis. In the study, formic acid, furfural, and hydroxypropanone were used as model components. To enhance catalyst activity, nickel was loaded onto the HZSM-5 catalyst. However, during biofuel production, a significant amount of coke was formed as a by-product. Therefore, cobalt was impregnated to reduce coke formation. In the activity test studies, a conversion in the range of 77–84% was achieved with HZSM-5 catalysts. Nickel addition increased the paraffin and olefin content in the biofuel along with bio-oil conversion. The maximum paraffin selectivity (97%) was provided with the 5Ni@HZSM-5 catalyst. However, the highest biofuel selectivity (77.5%) with the minimum coke formation (4%) was observed with the 5Co-5Ni@HZSM-5. In the study, the regeneration and long-term catalytic activity were also investigated, and the results showed that 5Co-5Ni@HZSM is an attractive catalyst for biofuel production from bio-oil. [ABSTRACT FROM AUTHOR]

Biochar is recognized for its potential in mitigating climate change, especially through carbon sequestration and soil improvement. To this end, it is important to use all co-products from pyrolysis in a sustainable and economically viable way. In this study, the conversion of sugarcane bagasse at varying pyrolysis temperatures was investigated using 1H NMR spectroscopy and Chenomx for liquid fraction analysis. The yield of biochar decreased significantly from 45.3 to 3.5% with a temperature increase of 300 to 1000 °C. The morphological analysis revealed that biochar produced at lower temperatures (300 °C and 400 °C) showed tubular and spongy structures, whereas at higher temperatures (600 °C and 800 °C), the structures morphed into holes and thinned further, ultimately degrading further at 1000 °C. All samples of biochar showed characteristics promising for soil improvement and carbon sequestration (O/C < 0.4). The analysis of liquid fractions revealed that biomethanol reached its highest concentration of 19.28 mM at 800 °C, which coincided with the highest production of acetic and lactic acids. Additionally, the highest concentration of acetone was observed at 600 °C. These findings highlight the importance of optimizing pyrolysis conditions for enhanced yields of biochar and platform compounds, as well as the potential of the NMR and Chenomx in bioenergy research. [ABSTRACT FROM AUTHOR]

As a common necessity, masks have been used a lot in recent years, and the comprehensive utilization of waste masks has become a research priority in the post-COVID-19 pandemic era. However, traditional disposal methods suffer from a range of problems, including poor utilization and insecurity. To explore new solution ideas and efficiently utilize waste resources, waste masks and biomass wastes were used as raw materials to prepare mask-based biochar (WMB), bio-oil, and pyrolytic gas via oxygen-limited co-pyrolysis in this study. The obtained solid–liquid–gas product was systematically characterized to analyze the physicochemical properties, and the adsorption properties and mechanisms of WMB on the environmental endocrine bisphenol A (BPA) were investigated. The co-pyrolysis mechanisms were also studied in depth. Furthermore, the strengths and weaknesses of products prepared by co-pyrolysis and co-hydrothermal synthesis were discussed in comparison. The results indicated that the waste masks could shape the microsphere structure, leading to richer surface functional groups and stable mesoporous of WMB. Here, the risk of leaching of secondary pollutants was not detected. The theoretical maximum adsorption of BPA by WMB was 28.73 mg·g−1. The Langmuir and Pseudo-second-order models optimally simulated the isothermal and kinetic adsorption processes, which are a composite of physicochemical adsorption. Simultaneous pyrolysis of mask polymers with biomass polymers produces bio-oil and pyrolytic gas, which is rich in high-quality aliphatic and aromatic compounds. This could have potential as an energy source or chemical feedstock. The co-pyrolysis mechanisms may involve the depolymerization of waste masks to produce hydrocarbons and H radicals, which in turn undergo multi-step cleavage and oligomerization reactions with biomass derivatives. It is recommended to use the co-pyrolysis method to dispose of waste masks, as the products obtained are significantly better than those obtained by the co-hydrothermal method. This work provides a new contribution to the resourcing of waste masks into high-quality products. [ABSTRACT FROM AUTHOR]

Bio-oil is a promising alternative energy source, offering a potential substitute for conventional fuels upon upgrading. This study is focused on extracting Solanum virginianum bio-oil using various solvents to compare the yields. Bio-oil derived from different feedstocks, including used cooking oil and non-edible sources, shows a calorific value of approximately 35 MJ/kg and a viscosity of 40 cP at 40°C. The energy density of this material, ranging from 20 to 25 MJ/kg, is comparable to traditional fossil fuels, making it a viable option for power generation. The ease of storage and transportation of this oil enhances its attractiveness to gaseous fuels. The applications of bio-oil include its use in gas turbines, diesel engines, and boilers and as a biofuel for transportation. Soxhlet extraction, known for its efficiency, simplicity, and cost-effectiveness, has been used to extract compounds from Solanum virginianum seeds. The proposed method is widely applied across industries, including natural products, environmental analysis, food, pharmaceuticals, and chemical analysis. [ABSTRACT FROM AUTHOR]

Biomass, as a renewable energy source, features wide availability, multiple functions, and carbon neutralization. The high-value resource utilization of biomass is conducive to reducing reliance on high-carbon fossil energy, ensuring national energy security, and curbing environmental pollution, aligning with the needs of China's "dual carbon" national strategy. Pyrolysis, as the foundation of biomass thermochemical conversion, is one of the best technologies to achieve a high-value utilization of biomass energy. However, it has some core issues such as low bio-oil yield and poor quality. To overcome these problems, a cryogenic technology was innovatively applied to the field of biomass pyrolysis, and a new biomass oil production method of "cryogenic + fast pyrolysis" was proposed to increase the yield and quality of pyrolytic bio-oil. Taking two types of crop straw as experimental research objects, the rapid freezing pretreatment method with liquid nitrogen was adopted to study the evolution mechanism of the product distribution and composition of biomass pyrolysis under cryogenic pretreatment. The experiments show that compared with conventional pyrolysis, the increase in the bio-oil yield after cryogenic pretreatment of biomass pyrolysis can reach 14.16% to 23.73%, and the cryogenic pretreatment temperature has a positive correlation with the bio-oil yield, and the maximum bio-oil yield (22.3% to 26.3%) is reached at −90 ℃, exceeding the bio-oil yield of the aluminum method by 8.50% to 22.71%. The cryogenic pretreatment has a significant transformation effect on the composition of the bio-oil, and the content of benzene series (BTEX) and phenolic substances in the bio-oil composition increases significantly, with the maximum increase of 43.61% and 12.45%, respectively. The cryogenic pretreatment of liquid nitrogen inhibited the release of CO2 and CO in biomass pyrolysis gas, and the proportion of components decreased by 7.2%−29.7%. In addition, the inhibition of the release of CO2 and CO in the biomass pyrolysis gas and the increase of CH4 and H2 by cryogenic pretreatment increase by 0.2% to 14.7%. Moreover, the increase in C content and the decrease in O content in the solid product under cryogenic pretreatment are conducive to improving the combustibility of biochar and reducing its risk of spontaneous combustion.

Abstract Electrospinning is utilized to fabricate catalytic nanofiber scaffold for biocrude upgrading in hydrodeoxygenation (HDO) following computational studies suggesting the need for nano-catalysts for efficient HDO conversion and selectivity. Here, Pt-TiO2 nanofibers are fabricated through electrospinning, followed by wet impregnation with a heteropoly acid (HPA), tungstosilicic acid. Intensive heat treatments were incorporated during and after processes to obtain a HPA doped Pt-TiO2 nano-catalyst. Catalytic HDO was performed in a batch reactor with phenol as the raw biocrude dissolved in hexadecane. The HPA doped Pt-TiO2 catalyst demonstrated promising HDO performance of 37.2% conversion and a 78.9% selectivity to oxygen free benzene and the remainder 21.1% as diphenyl ester as a result of esterification by acidic components of the catalyst. Additionally, BET surface area characterization show a low surface area 16.9 m2 g−1 significantly lower than existing commercial catalysts and a mesoporous nature suitable for selectivity. The presence of HPA on the anatase nanofiber compensated for low platinum nanoparticles crystallinity on the nanofibers. This work might create needed alternatives for preparing HDO catalysts for efficient aromatics production.

Alternative biomass for energy can reduce fossil fuel use and environmental impacts, providing energy security in semi-arid areas with shallow soils that are not ideal for agro-forestry. The densification of sorghum biomass (SB) brings its energetic characteristics closer those of wood. Higher heating value (HHV) represents the heat produced by a given quantity of fuel. This Brazilian research tested different mixtures of SB, eucalyptus wood (W), and eucalyptus bio-oil (Bo) as briquettes for HHV and least ash. Compressed mixtures of SB+B were compared to W+Bo and SB+W+Bo. The concentrations of bio-oil added to SB/W were 1%, 3%, 4%, and 5%. SB+W+Bo composites’ W content was 0%, 25%, 50%, 75%, and 100%, with Bo as 3% of the weight. Sorghum biomass’ HHV is equivalent to W at 3%Bo. Bo doses of 4% and 5% had the same HHV as 3%. Eucalyptus wood did not have a significantly greater HHV with any amount of Bo. SB+W+3%Bo had the same HHV as W when W was at least 50% of the mixture. At greater than 36%W, the ash content was lower than 3%, meeting the EN-B international standard. The optimal composite mixture was 64%SB+36%W+3%Bo for HHV and ash content. SB briquettes can be more widely adopted given sorghum’s prevalence in semi-arid environments.

The purpose of this study is to demonstrate the potential of ceramic tile dust (CTD)-derived ZSM-5 zeolite (CZ) and its monodispersed composite with metal oxides (MgO and Fe2O3) in the catalytic pyrolysis of hyphaene thebaica shell (HTS). The HTS was pyrolysed in a Fixed-bed reactor at 400–600 °C, and 100–300 mL/min N2 flowrate. The maximum bio-oil production of 32 % was obtained at 500 °C and 150 mL/min N2 flowrate, with bio-oils containing 50 % acid and octadecenoic acids, as well as esters, phenols, aldehydes, ketones, ethers, aromatics, and hydrocarbons. A carboxymethyl cellulose templating agent was employed for the mesoporous zeolite synthesis from CTD. This resulted in the mesoporous zeolite with a predominant ZSM-5 crystal phase, exhibiting pore diameters ranging from 1.8-6 nm, 229 m2/g surface area and 1145 μmol/g total acidity. The catalytic pyrolysis of HTS was conducted using the ZSM-5 zeolite (CZ) and metal-oxide (MgO, Fe2O3, and Fe2O3/FeO) modified CZ, as monodispersed composite catalysts. Under best thermal pyrolysis conditions, CZ-Fe2O3, CZ-MgO, and CZ-Fe2O3/MgO demonstrated 22–23 % bio-oil yields. Notably, the CZ-Fe2O3/MgO catalyst exhibited the highest hydrocarbon yield at 16 %, while the CZ-MgO favoured the production of phenolics, esters, and alcohols. CZ-MgO also displayed the highest coking level at 7.5 %, indicating faster deactivation than the other catalysts. The synthesised catalysts exhibited remarkable catalytic activity, resulting in a notable improvement in the quality of bio-oils obtained from the intermediate pyrolysis of hyphaene thebaica shells in a fixed-bed reactor.

The world energy consumption has increased by + 195% since 1970 with more than 80% of the energy mix originating from fossil fuels, thus leading to pollution and global warming. Alternatively, pyrolysis of modern biomass is considered carbon neutral and produces value-added biogas, bio-oils, and biochar, yet actual pyrolysis processes are not fully optimized. Here, we review the use of machine learning to improve the pyrolysis of lignocellulosic biomass, with emphasis on machine learning algorithms and prediction of product characteristics. Algorithms comprise regression analysis, artificial neural networks, decision trees, and the support vector machine. Machine learning allows for the prediction of yield, quality, surface area, reaction kinetics, techno-economics, and lifecycle assessment of biogas, bio-oil, and biochar. The robustness of machine learning techniques and engineering applications are discussed. [ABSTRACT FROM AUTHOR]

Biochar production from biomass sources is a highly complex, multistep process that depends on several factors, including feedstock composition (e.g., type of biomass, particle size) and operating conditions (e.g., reaction temperature, pressure, residence time). However, the optimal set of variables for producing the maximum amount of biochar with the required characteristics can be determined by using machine learning (ML). In light of this, the purpose of this paper is to examine ML applications in biochar processes for the production of sustainable fuels. First, recent developments in the field are summarized, and then, a detailed review of ML applications in biochar production is presented. Following that, a bibliometric analysis is done to illustrate the major trends and construct a comprehensive perspective for future studies. It is found that biochar yield is the most common target variable for ML applications in biochar production. It is then concluded that ML can help to detect hidden patterns and make accurate predictions for determining the combination of variables that results in the desired properties of biochar which can be later used for decision-making, resource allocation, and fuel production. [ABSTRACT FROM AUTHOR]

This study aims to optimize bio-oil production through microwave pyrolysis of Triplochiton scleroxylon sawdust (Ayous). After a physicochemical characterization of the sawdust, response surface methodology via centered composite design was used to investigate the influence of pyrolysis factors on bio-oil yield and determine the optimal pyrolysis conditions. The studied pyrolysis factors were microwave power (W), irradiation time (min), and biochar (%) as wave absorber. Finally, the bio-oil produced under optimal conditions was characterized by GC–MS. It emerges from this study that Ayous biomass has physicochemical properties that can be valorized for bio-oil production, with a high volatile matter content (63.2 ± 2%) and low ash content (2.8 ± 0.3%). The optimization study of bio-oil yield shows that all factors have significant effects with a statistical significance level of 5% (p < 0.05) on the measured parameters. The optimal bio-oil yield of 44.82% is obtained at optimal conditions: microwave power of 576 W, irradiation time of 28 min, and a biochar (wave absorber) input of 3.18%. The bio-oil produced under optimal conditions has a pH of 4.6 ± 0.7 and a water content of 25 ± 1.2%. Compound identification of this bio-oil by GC–MS identified families of compounds including alkanes (13.90%), esters (5.88%), alcohols (1.10%), and high molecular weight phenolic compounds (58%). The produced bio-oil can be used as biofuel or in industrial applications. Nevertheless, further processing steps are needed to lower the water content and acidity of the oil. [ABSTRACT FROM AUTHOR]

This study examines the intricate thermal decomposition of sweet sorghum bagasse, an agricultural residue with significant potential as a renewable energy and biofuel feedstock. Both slow and flash pyrolysis has been conducted over a temperature range of 300–450°C and flash pyrolysis experiments were performed through analytical pyrolysis via Py-GC/MS to comprehensively assess the pyrolysis behaviour and elucidate the biomass degradation pathways. In the slow pyrolysis experiments, sweet sorghum bagasse underwent controlled thermal decomposition at different temperatures (300–450°C), allowing for the investigation of the influence of temperature on product yields and compositions. The evolved volatile compounds and biochar products were analyzed to determine the impact of temperature on biomass degradation. The results revealed that 400°C is the optimum pyrolysis temperature for maximizing valuable bio-oil production with approximately 42 wt.% yields with an overall conversion of 73%. Various characterization techniques were employed to analyze the slow pyrolysis products, including GC-MS, TGA, FTIR, SEM, and XRD. Flash pyrolysis was employed to provide a detailed understanding of the rapid biomass breakdown under extreme heating conditions with a heating rate of 20°C/ms to complement the slow pyrolysis findings. This technique elucidated the primary mechanisms responsible for the degradation of sweet sorghum bagasse, shedding light on the fragmentation patterns and the formation of vital intermediate compounds during flash pyrolysis. These insights into the transient phenomena occurring during pyrolysis provide valuable information for developing efficient and sustainable biomass conversion processes. The pyrolysis behaviour of sweet sorghum bagasse (SSB) is comprehensively assessed using TGA, slow pyrolysis via lab scale glass tubular reactor and flash pyrolysis via analytical tool Py-GC/MS from 300–450°C. The study reveals the potential use of SSB as a renewable energy and biofuel feedstock. [ABSTRACT FROM AUTHOR]

Biofuel is an alternative fuel for diesel engines which is necessary to reduce exhaust emissions and helps to balance the depletion of fossil fuels. This study details the synthesis of bio-diesel and bio-oil from stone apple seeds (Aegle marmelos) through transesterification, direct oxygenate additive, and pyrolysis processes. The diesel engine is powered by the resulting stone apple methyl ester bio-diesel/diesel and bio-oil/diesel mixtures. In a test engine rig, the effectiveness and emission uniqueness of test fuel mixes were examined at various engine loads (EL = 3 kg–12 kg) and compression ratios (CR = 16–17.5) while maintaining a steady speed of 1500 r/min. Furthermore, engine performance and emissions for bio-diesel and bio-oil are measured and compared. The oxides of nitrogen (NOx) emission by bio-diesel and bio-oil opus were higher than neat diesel (FD). Also, carbon monoxide (CO) and hydrocarbon (HC) emissions were measured to be lower. The improvements of BTE by 4.87% and decrement of CO by 18.8%, HC by 13.26% were observed with the trans-esterified bio-diesel/diesel opus compared to diesel at a higher CR and rated load conditions. The engine analysis responses revealed that the FBD blend showed enhanced performance and lower emissions except NOx compared to diesel fuel. Hence, trans-esterified bio-diesel is a greater diesel alternative than FBDE and FBO. [ABSTRACT FROM AUTHOR]

In the search for an eco-friendly fuel, bio-oil is a promising alternative to fossil fuels due to its potential to reduce environmental impacts and its versatility in various applications. According to the International Energy Agency, biofuel demand will increase by 41 billion liters, or 28%, between 2021 and 2026. About 5% of the primary energy in the United States in 2021 came from biomass resources, producing nearly 5,000 trillion BTU. However, a major challenge facing bio-oil production is the limited lignocellulosic biomass resources as feedstock and the costly supply chain. Non-edible plant seeds are abundant as fruity plants and yield bio-oil with good heating values, but they are yet to get the required attention. They are usually discarded after consuming their mesocarp, contributing to environmental waste. Also, bio-oil requires improvement due to various issues like strong corrosive effects, high acidity, and a high water content. This review, therefore, provides an overview of the bio-oil from waste plant seeds as lignocellulosic biomass feedstocks for producing biofuel using pyrolysis. The findings reveal an average 47.85% bio-oil yield from plant seeds with more bioenergy value than that from other tree parts' biomass resources; it can be upgraded using catalytic, co-pyrolysis, and distillation improvement approaches for its potential usage as an energy source. This highlight also provides the future and challenges of using this bio-oil as an alternative energy source, presenting a clean and affordable biofuel production feedstock that can mitigate climate change through a cleaner environment, plus new ways of recycling waste.

Asphalt binder is the most common material used in road construction. However, the need for more durable and safer pavements requires a better understanding of asphalt's aging mechanisms and how its characteristics can be improved. The current challenge for the road industry is to use renewable materials (i.e., biomaterials not subjected to depletion) as a partial replacement for petroleum-based asphalt, which leads to reducing the carbon footprint. The most promising is to utilize biomaterials following the principles of sustainability in the modification of the asphalt binder. However, to understand whether the application of renewable materials represents a reliable and viable solution or just a research idea, this review covers various techniques for extracting bio-oil and preparing bio-modified asphalt binders, technical aspects including physical properties of different bio-oils, the impact of bio-oil addition on asphalt binder performance, and the compatibility of bio-oils with conventional binders. Key findings indicate that bio-oil can enhance modified asphalt binders' low-temperature performance and aging resistance. However, the effect on high-temperature performance varies based on the bio-oil source and preparation method. The paper concludes that while bio-oils show promise as renewable modifiers for asphalt binders, further research is needed to optimize their use and fully understand their long-term performance implications. [ABSTRACT FROM AUTHOR]

Sugarcane bagasse is one of the greatest biomass residues obtained from fuel industry, and the lignin present in sugarcane fibers is rich in phenolic compounds, which can be used to replace petroleum-derived phenols in the formulation of adhesives, phenolic resins, plasticizers, paints, among others. This work presents an alternative for synthesizing and applying bio-oil based benzoxazine resins in the fabrication of "green" medium density fiberboard. In this new concept, the wood fiber is substituted by the sugarcane bagasse fiber, and the fossil-based resin is substituted by the bio-based benzoxazine resin. To produce the bio-oil resin, 200.0 g of bio-oil, 64.9 mL of formaldehyde, 39.4 mL of aniline, and 80.0 mL of butanone were added along the different process stages. Three concentrations of bio-oil resin were used to produce fiberboards, 25, 30, and 35%. The results of characterizations were compared with fiberboards made with regular urea–formaldehyde resin, in the same concentrations. Results indicated that bio-oil can be used successfully for the development of a thermosetting resin (BO-resin), as observed by thermal and spectroscopic analysis. All BO-resin MDF formulations had densities according to international standards, between 651 and 800 kg m-3, and reached the required thickness swelling when applied in concentration of 35% resin. The modulus of rupture (MOR) showed elevated values (around 15 MPa), similar to fiberboards made from urea–formaldehyde resins. These results indicate the promising potential of using sugarcane bagasse for the full development of novel bio-based materials with technological application. [ABSTRACT FROM AUTHOR]

Catalytic co-pyrolysis of two different refinery oily sludge (ROS) samples was conducted to facilitate resource recovery. Non-catalytic pyrolysis in temperatures ranging from 500 to 600°C was performed to determine high oil yields. Higher temperatures enhanced the oil yields up to ~ 24 wt%, while char formation remained unchanged (~ 45%) for S1. Conversely, S2 exhibited a notably lower oil yield (~ 4 wt%) than S1. Pyrolysis oil of S1 consisted of phenolics (~ 50% at 600 °C) whereas hydrocarbons were predominant in S2 oil (~ 80% at 600 °C). Catalytic pyrolysis of S1 did not exhibit a substantial impact on oil yields but the oil composition varied significantly. High hydrocarbons, phenolics, and aromatics were obtained with molecular sieve (MS), metal slag, and ZSM-5, respectively. Catalytic co-pyrolysis of S2 with sawdust (SD) in the presence of MS enhanced the oil yield, and the resulting oil consisted of high hydrocarbons (~ 54%) and aromatics (~ 44%). [ABSTRACT FROM AUTHOR]

Biomass‐based hard carbon has the advantages of a balanced cost and electrochemical performance, making it the most promising anode material for sodium‐ion batteries. However, due to the structural limitations of biomass (such as macropores and impurities), it still faces the problems of low specific capacity and initial Coulombic efficiency (ICE). Herein, an integrated strategy of biomass liquefaction and oxidation treatment is proposed to fabricate hard carbon with low ash content and sp2‐rich closed pores. Specifically, liquefaction treatment can break through the inherent constraints of biomass, while oxidation treatment with O‐targeted effect can directionally convert C─C/C─O bonds into C═O/O═C─O bonds, which would promote the formation of closed pores and the rearrangement into sp2‐carbon within the graphene layer. Moreover, it is well demonstrated that the hard carbon interface rich in sp2 hybridization can induce the generation of an inorganic‐rich solid electrolyte interface, contributing to fast ion migration and excellent interfacial stability. As a result, the optimized hard carbon with maximum closed pore volume and sp2/sp3 ratio can exhibit a high capacity of 347.3 mAh g−1 at 20 mA g−1 with the ICE of 90.5%, and a capacity of 110.4 mAh g−1 at 5.0 A g−1 after 10 000 cycles. [ABSTRACT FROM AUTHOR]

In recent years, algae have emerged as a promising feedstock for biofuel production, due to their eco-friendly, sustainable, and renewable nature. Various methods, including chemical, biochemical, and thermochemical processes, are used to convert algal biomass into biofuels. Pyrolysis, a widely recognized thermochemical technique, involves high temperature and pressure to generate biochar and bio-oil from diverse algal sources. Various pyrolytic processes transform algal biomass into biochar and bio-oil, including low pyrolysis, fast pyrolysis, catalytic pyrolysis, microwave-assisted pyrolysis, and hydropyrolysis. These methods are utilized to convert a range of microalgae and cyanobacteria into biochar and bio-oil. In this publication, we will discuss catalytic pyrolysis using mesoporous materials, such as SBA-15. Mesoporous catalysts have earned significant attention for catalytic reactions, due to their high surface area, facilitating the better distribution of impregnated metal. Pyrolysis conducted in the presence of a mesoporous catalyst is viewed more as efficient, compared to reactions occurring within the smaller microporous cavities of traditional zeolites. SBA-15 supports with incorporated Zr and/or Ce were synthesized using the direct hydrothermal synthesis method. The catalyst was characterized using structural and morphological technical analysis and utilized for the pyrolysis reaction of the algal biomass. [ABSTRACT FROM AUTHOR]

Research to date has mainly focused on the properties and efficiency of the production of selected, individual types of biofuels from microalgae biomass. There are not enough studies investigating the efficiency of the production of all energy sources synthesised by these microorganisms in a single technological cycle. The aim of this research was to determine the possibilities and efficiency of the production of hydrogen, bio-oil, and methane in the continuous cycle of processing T. subcordiformis microalgae biomass. This study showed it was feasible to produce these three energy carriers, but the production protocol adopted was not necessarily valuable from the energy gain standpoint. The production of bio-oil was found to be the least viable process, as bio-oil energy value was only 1.3 kWh/MgTS. The most valuable single process for microalgae biomass conversion turned out to be methane fermentation. The highest specific gross energy gain was found after applying a protocol combining biomass production, hydrogen biosynthesis, and subsequent methane production from T. subcordiformis biomass, which yielded a total value of 1891.4 kWh/MgTS. The direct methane fermentation of T. subcordiformis biomass enabled energy production at 1769.8 kWh/MgTS. [ABSTRACT FROM AUTHOR]

Agricultural residue is an important biomass resource in China. Utilization of agricultural residue for production of high-quality fuel oil is an attractive and challenging topic towards the goals of “Carbon Peaking and Carbon Neutrality”. Biomass hydropyrolysis integrated with volatile catalytic hydrogenation is a new process that can efficiently improve the yield and quality of bio-oil. This work is purposed to explore this new biomass conversion technology by laboratory experiments using a tandem pressurized fixed bed reactor. A bimetallic molecular sieve catalyst (NiMo-HZSM-5) was prepared by an impregnation method and used for catalytic hydrogenation. Biomass was hydropyrolyzed under a condition of 5 MPa H2 pressure, 15℃/min heating rate and 700℃ final temperature to generate volatile matter, which was online hydrogenated through the NiMo-HZSM-5 catalyst bed under a condition of 5 MPa H2 pressure, 320℃ reaction temperature and 26 s residence time (corresponding to space velocity of 112.5 h−1 ). The paper firstly presents the oil production results of three types of agricultural residue, corn stalk, cotton stalk and peanut straw by the catalytic hydrogenetion. The paper is then devoted to further clarifying the conversion characteristics of different biomass fiber constituents by means of the water washing and acid washing pretreatments of three agricultural residues as well as by adopting cellulose and lignin as model compounds. Results showed that in the case of non-catalytic hydrogenation, all of the bio-oils obtained from three agricultural residues contained oxygenates and aromatic hydrocarbons as two main classes of compounds, and that from peanut straw also contained a high proportion of nitrogenous compounds. In contrast, all of the bio-oils derived from three agricultural residues by the catalytic hydrogenation (CH bio-oils) contained almost neither oxygenates nor nitrogenous compounds. The yields of CH bio-oils reached 10.3%–15.9% for three agricultural residues. The CH-bio-oils were composed of 73.0–84.8% saturated aliphatic hydrocarbons (mainly cyclopentanes, cyclohexanes, and perhydro- naphthalenes), 6.1%–13.1% partially hydrogenated aromatic hydrocarbons (mainly di-, tetra-hydronaphthalenes) and a small amount of monocyclic aromatic hydrocarbons. The result highlights that the two-stage process of hydrogenation pyrolysis integrated with NiMo-HZSM-5 catalytic hydrogenation can effectively convert agricultural residue into a kind of high-quality bio-oil composed mainly of alicyclic hydrocarbons. The water washing could remove about half of neutral extractives from each of three agricultural resides. After the water washing, three agricultural residues showed increases in the yields of CH bio-oil to 18.1%–18.5%, suggesting that neutral extractives are less conducive to the production of CH bio-oil compared to other fiber components. The acid washing enabled cellulose and lignin to be left in the agricultural residues as main components. Via this pretreatment, the yields of CH bio-oil increased to 18.2%–22.5% for three agricultural residues, with cotton stalk having the highest yield. The yields of typical aliphatic hydrocarbon compounds (methyl-cyclopentane, methyl-cyclohexane and decahydro-naphthalene) from all three agricultural residues were increased by the acid washing. The study using model compounds revealed that cellulose is a fiber for not only achieving a high yield of CH bio-oil but also selectively producing aliphatic hydrocarbon compounds such as cyclopentane, cyclohexane, and decahydro-naphthalene. Meanwhile, lignin has a lower yield of bio-oil, and it tends to produce monocyclic aromatic hydrocarbons. Lignin can also generate cyclohexane compounds and partially hydrogenated polycyclic aromatic hydrocarbons, but it has a low propensity to the formation of cyclopentane compounds. This study has provided a new technical route to utilizing agricultural residues for high-efficient production of fuel oil. [ABSTRACT FROM AUTHOR]

The creation of conditions for the rational and multipurpose use of forests has become an urgent task within the forest industry. There is an active search for opportunities to use bio-oil derived from wood waste obtained through fast ablative pyrolysis. Bio-oil has a rich chemical composition, making it relevant to isolate individual chemical components from it. The main objective of this work was to investigate a method for extracting the phenolic fraction from the pyrolysis fluid of wood waste and to obtain and study samples of side fractions obtained during phenolic extraction. This paper describes a method for the fractionation of wood waste pyrolysis fluid based on a multi-stage complex process, including vacuum distillation, liquid-liquid extraction, and acidalkali precipitation. A detailed description and scheme of the processes are presented in the paper. The properties and chemical compositions of the obtained fractions were investigated. In the fractionation process, a phenolic fraction containing at least 60.38% of phenolic compounds was isolated. The first stage of the separation produces a fraction with a high content of acetic acid, while the third stage leads to the separation of a fraction containing sugars. Additionally, a fraction containing up to 22% furfural is formed. The fractions obtained at each separation step have both scientific and commercial potential, in addition to the target phenolic fraction. [ABSTRACT FROM AUTHOR]

This study investigates the potential of utilizing pyrolysis byproducts, including char and non-condensable gases, as an energy source to promote autothermal pyrolysis. A total of six pyrolysis experiments were conducted at three distinct cracking temperatures, namely, 450 °C, 500 °C, and 550 °C. The experiments utilized two types of biomasses, i.e., 100% pine chips and 75% pine chips mixed with 25% refuse-derived fuels (RDF). The findings from the experiments were subsequently incorporated into a process simulation conducted on Aspen Plus for an energy balance and a techno-economic analysis. The results of the experiments revealed that the energy produced by the byproducts utilizing only pine chips is 1.453 kW/kg, which is enough to fulfill the energy demand of the pyrolysis reactor (1.298 kW/kg). However, when 25% of RDF is added, the energy demand of the reactor decreases to 1.220 kW/kg, and the produced energy increases to 1.750 kW/kg. Furthermore, adding RDF increases bio-oil's lower heating value (LHV). The techno-economic study proposed three scenarios: optimistic, conservative, and tragic. The optimistic has a payback period (PBP) of 7.5 years and a positive net present value (NPV). However, the other two scenarios were unfavorable, resulting in unfeasibility. [ABSTRACT FROM AUTHOR]

Hydrothermal liquefaction (HTL) is an efficient technology for converting biomass to platform compounds. It has great potential for reducing the dependence on fossil fuels. The HTL of waste biomass has been extensively studied in recent years due to both its environmental and economic benefits. However, most woody waste contains a large amount of cellulose, and it is difficult to be sufficiently decomposed to valuable chemicals. Phycocyanin, a key component of algae, is easily degraded under high-temperature liquefaction conditions. In this work, focusing on bio-oil generation properties, the co-liquefaction characteristics and synergistic mechanisms of a-cellulose and phycocyanin were explored. The findings revealed a maximum bio-oil yield of 33.1 wt% under the optimal conditions (300 °C for 40 min), with a notable positive synergistic effect of 13.5 wt%. Chemical composition analysis indicated distinct compositional differences between the bio-oils derived from individual and dual feedstock. The amounts of pyridine and pyrimidine compounds increased due to the enhanced co-liquefaction. The results also highlighted the influence of temperature on the degree of conversion and product distribution. Finally, preliminary chemical reaction pathway was elucidated, underscoring the potential of integrating microalgae and woody biomass for enhanced bio-oil production. [ABSTRACT FROM AUTHOR]