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Under the circumstances of serious environmental challenges and energy crises, it is of utmost importance to produce fuels and chemicals from renewable biomass and organic wastes. Biochar as a bioproduct from thermochemical conversion of biomass has attracted exponential research interest in recent years due to the abundance of its precursor (biomass resources) and its adaptability in different chemical reaction systems. Undoubtedly, it is essential to attain an in-depth understanding of the physiochemical properties and functionalization of biochar catalysts to further improve their catalytic activity, selectivity and stability in the reactions. However, until now, only a few reports are accessible on the use of biochar as a catalytic support material and/or a standalone catalyst in thermochemical biomass conversion to produce high-quality biofuels. Thus, the key objective of this review article is to summarize and discuss the latest progress in biochar production, modification, activation and functionalization by understanding its physical chemistry, composition and application in catalytic processes. This review article provides insights into the thermochemical and hydrothermal production of biochar as well as the engineering and process optimization aspects for value-added biofuel production and decarbonization. [Display omitted] • Effects of biomass composition and process conditions on biochar are reviewed. • Systematic discussion on biochar functionality as bio-based catalyst support is made. • Insights into the modification of biochar targeting optimal performance are shown. • Comparative analysis of biochar-based catalytic pyrolysis, gasification and liquefaction. • The significance of activation of biochar for enhanced functionality is justified. [ABSTRACT FROM AUTHOR]

The study explores the synthesis and utilization of biochar (BC) and multi-layer MXene to MXene/biochar (MB) composites for wastewater treatment. Simultaneously, it also investigates their energy generation potential through biomass and soil property assessments. The integrated column and batch treatments have shown significant results, elevating total dissolved solids from 63.7 to 125.5 mg L−1 with column treatment, while reducing them to 6.37 % and 1.35 % with BC and MB treatment, respectively. BC with high carbon content, demonstrated increased hydrophobicity, which was amplified by the integration of MXene, thereby enhancing its potential for advanced wastewater treatment. Treated wastewater exhibited elevated nutrient concentrations (Ca, Cu, Fe, K, Na, and NH 4 +), promoting the growth of Pennisetum purpureum. WW_B shows promising energy potential, with a higher heating value of 25.03 MJ kg−1 and a lower heating value of 23.57 MJ kg−1. They demonstrated high volatile matter exceeding 70.9 wt %, and a fixed carbon from 10.02 to 27.53 wt %, signifying their potential for efficient conversion and bio-oil yield during pyrolysis. The ultimate analysis emphasized significant carbon, with oxygen content ranging from 43.42 to 47.78 wt %., influencing combustion characteristics. MT_B exhibited its suitability for energy production through thermochemical conversion, underlined by its high flammability and low volatile ignition values. In the absence of BC, the E a ranged from 24.77 to 77.88 kJ mol−1 in wastewater and from 21.67 to 69.6 kJ mol−1 in MB treated wastewater. Meanwhile, when soil contained BC and was irrigated with wastewater, the E a varied from 24.66 to 80.91 kJ mol−1. In the case of MB treated wastewater, it ranged from 25.01 to 75.79 kJ mol−1. The research thereby affirms the potential of MB composites to advance water and energy sustainability setting us for broader nexus-based applications. [Display omitted] • Wastewater reclamation within the context of sustainable energy generation was studied. • Pennisetum purpureum exhibited promising bioenergy production potential using MT_B. • Crops, with WW_B having even higher VM, exhibited high VM exceeding 70.9 %. • WW_B's high HHV (25.03 MJ kg − 1 ) and LHV (23.57 MJ kg − 1 ) indicate promising energy potential for thermochemical conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Efficient co-valorization of waste cooking oil into biofuel and carbon nanotubes. • Natural biochar shows excellent deoxygenation performance and good stability. • Correlation between AAEM in biochar and selectivity of A&E and HCs in bio-oil. • Potential for obtained biofuel to serve as a precursor for jet fuel. • Feasibility and profitability of integrated production process demonstrated. Valorizing renewable precursors into high-quality biofuel and functional carbon nanomaterials can considerably improve the economic viability. Here, we propose a process for integrated production of high-quality biofuel and carbon nanotubes from waste cooking oil via catalytic pyrolysis coupling with chemical vapor deposition (CVD) technology. The natural biochar catalyst demonstrates excellent deoxygenation performance and good stability in catalytic pyrolysis process. The alkali/alkaline earth metal species (AAEMs) content in biochar catalysts has a strong correlation with the selectivity of esters and hydrocarbons in bio-oil. The biofuel obtained under optimal conditions exhibited potential as a precursor for jet fuel. The CVD process convert pyrolysis gas into carbon nanotubes with yield of 2.13%. The technical–economic analysis demonstrated the feasibility of the integrated process, projecting profitability and substantial total profit over a ten-year period. Overall, this study improves the economic viability of the waste cooking oil pyrolysis process and supports its wider commercial application. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) is a process for enhancing energy content of biomass through deoxygenation reactions, effectiveness of which depends on composition of biomass. Thermal pretreatment could induce structural change of biomass and thus affects the chemical inertness/reactivity in HTC. This was investigated herein by HTC of the pine needles, thermally treated at 250 or 350 °C with/without presence of 11.5% O 2 , at 250 °C for 10 h. The results showed that pretreatment at 250 °C could increase overall yield of hydrochar in subsequent HTC, due to the enhanced aromatization and the resistance towards fragmentation in HTC. Nonetheless, the HTC worked on biochar formed at 250 °C, facilitating deoxygenation to remarkably decrease O/C ratio. In comparison, the pretreatment at 350 °C removed substantial amount of volatile fractions, significantly increasing chemical inertness of resulting char-350 during the followed HTC. Oxygen presence induced oxidation reactions in pretreatment, forming more bio-oil/gases and making resulting hydrochar more hydrophilic. Especially, oxidation at 250 °C formed more aliphatic structures that could be easier removed during followed HTC, enhancing thermal stability of resulting hydrochar. Although a portion of cellulose retained in the biochar obtained from pretreatment at 250 °C, the elimination of aliphatics suppressed formation of spheric structures of hydrochar, while retained original fibrous structures from pine needles. [Display omitted] • Pine needle pretreated at 250°C is more inert in HTC, generating more hydrochar. • HTC barely works the sample pretreated at 350°C, due to removing most of volatiles. • Pretreatment at 250°C retains cellulose crystals, which are removed at 350°C. • O2-pretreatment makes hydrochar thermally more stable via removing more aliphatics. • Pretreatment at even 250°C suppresses formation of hydrochar of spheric structures. [ABSTRACT FROM AUTHOR]

Solar energy and biomass produce energy, which is sustainable and does not harm our environment. This characteristic of the two-energy feedstock is harnessed using the pyrolysis method to produce liquid and gaseous fuel that is transportable while bio-char regarded as a by-product has found usefulness in soil amendments. Solar-biomass pyrolysis technology combines these two low-density energy feedstock to produce high energy density fuel. The effectiveness of this process depends not only on the feedstock or reaction dynamics but also on the solar-thermal systems and reactor configuration. This review addressed the benefits of solar-biomass pyrolysis, available optical concentrating device, conceptual heating modes, the existing configuration of solar-thermal and reactor orientations, and some basic model equations applied in solar biomass pyrolysis. [ABSTRACT FROM AUTHOR]

Enormous annual sewage sludge (SS) volumes pose global environmental challenges owing to contamination and significant greenhouse gas emissions. Here, we investigated the economic viability of co-pyrolyzing SS and biomass waste to produce biofuels (bio-oil and gas) and biochar. Net present worth (NPW) analysis, the sale product break-even price, and sludge handling price (SHP) were used to determine the profitability of co-pyrolysis compared with SS pyrolysis alone and conventional treatment methods. In this study, the sale prices of biochar based on quality (i.e., stability, carbon sequestration effectiveness, and heavy metal content) were estimated to be 2.24, 1.44, and 0.98 CAD/kg for high-, medium-, and low-grade biochar. The bio-oil prices, estimated based on the higher heating values of bio-oil and diesel, ranged from 0.80 to 1.22 CAD/kg. Sawdust (SD) and wheat straw (WS) were the chosen co-pyrolysis feedstocks, with four mixing ratios (20, 40, 60, and 80 wt%). Economically, SD (40 wt% mixing ratio) co-pyrolysis achieved the best performance, with a maximum NPW of 8.71 million CAD. SD single and co-pyrolysis were the only profitable scenarios. Moreover, SS single pyrolysis and WS co-pyrolysis exhibited higher profitability than conventional SS treatment methods, with SHPs of 65 and 40 CAD/1000 kg dry sludge, respectively. Sensitivity analysis highlighted the dependence of economic performance on biochar and bio-oil market value. This study offers the first economic analysis of this approach and enhances our understanding of the potential of co-pyrolysis for biofuel and biochar production, providing innovative solutions for the environmental challenges of SS disposal. [Display omitted] • Cost, operating expenses, and energy recovery of a pyrolysis plant were evaluated. • Co-pyrolyzing SS with sawdust SS showed the highest NPW of 8.71 million CAD. • All single and co-pyrolysis cases showed higher revenue than SS disposal methods. • Economic feasibility was dependent on bio-oil and biochar quality and sales price. [ABSTRACT FROM AUTHOR]

As the most promising anode material for ultra-high specific capacity lithium-ion batteries, Si has been hindered from widespread use by large volume effects and limited electrical conductivity during cycling. In this study, NiO nanoflowers were coated onto the exterior of Si NPs by hydrothermal method. Si@NiO was then mixed and annealed with natural biomass gel extracted from moldy wheat to produce Si@NiO@Biochar ternary composites, which were prepared. Si NPs are the source of high specific capacity of anode materials. The carbon layer minimizes the electrode bulk effect and enhances cycling stability, while the NiO flowers expand the lithium-ion transport channel and reduce Si NPs bulk effect. Furthermore, the N element from wheat protein in the carbon layer enhances the electrical conductivity of the material. After 100 cycles at 0.1 A g−1 and 1000 cycles at 1 A g−1, the capacity of the electrode rose to 952.12 mAh g−1 and 1098.05 mAh g−1, respectively. The Si@NiO@Biochar material showed remarkable electrochemical stability at various current densities and the thickness grew by just 27.97% after 500 cycles. It can also be utilized in lithium-sulfur batteries because of its microporous structure and capacity to transport sulfur. The reversible capacity was 388.21 mAh g−1 after 70 cycles at 1 C. Biomass carbon from biomass gels coated on Si@NiO reduces biomass energy waste. This research is a significant step for commercializing Si anode materials and providing an eco-friendly new method for storing energy. [Display omitted] • Nitrogen-doped biochar is made from the recycling of mouldy wheat. • The simple preparation process and excellent results. • The volume expansion of the silicon is well limited. • The composite has low internal resistance and high cycle life. • It can be used in two scenarios: lithium batteries and lithium- sulfur batteries. [ABSTRACT FROM AUTHOR]

Grass silage and cattle slurry are the most abundant feedstocks for biogas in an Irish context. This work describes how to optimize their biomethane yield. Hydrolysis and biomethane yields from co-digestion of grass silage and slurry were enhanced in a biochar-supplemented two-stage digestion process. Biochar addition at the optimal dosage of 10 g/L in batch two-stage digesters led to the highest methane yield of 253 L per kilogram (kg) volatile solid (VS), which was 24% higher than that from two-stage digesters without biochar supplementation. For a batch single-stage digester, the biomethane yields were lower than the two-stage but 10 g/L biochar addition led to an increase to 218 L/kg VS as compared to 198 L/kg VS for the group without biochar supplementation. Volatile fatty acid accumulation increased with the enhancement of biomethane production in the biochar-supplemented two-stage reactors. The addition of biochar in single-stage and two-stage anaerobic digesters presented positive effects on the electrochemical properties of the digester contents, reflected by the increased charge storage capacity, reduced solution resistance and improved digester content conductivity. The methane yields in two-stage anaerobic digestion were shown to be strongly correlated (R2 = 0.92) with the concentration of extracellular polymeric substances. This evidenced that the interlaced conductive network established by extracellular polymeric substances and biochar was essential for direct interspecies electron transfer and biomethane production. This study demonstrated that biochar-supplemented two-stage anaerobic digestion is an optimal route for energy recovery from grass silage and cattle slurry. [Display omitted] • Co-digestion of on-farm feedstock was enhanced in a two-stage process with biochar. • Biochar at 10 g/L in two-stage digestion maximized CH 4 yield at 253 L/kg VS. • Biochar at 10 g/L in single-stage digestion achieved a CH 4 yield of 218 L/kg VS. • Biochar improved sludge conductivity to facilitate interspecies electron transfer. • CH 4 yield highly correlated with extracellular polymeric substances concentration. [ABSTRACT FROM AUTHOR]

Involving biomass in the energy sector is a way to replace fossil fuels with renewable and CO 2 -neutral raw materials, reducing the negative impact on the environment. The energy application of agro-industrial waste is of particular interest, allowing one not only to obtain biofuel, but also to utilize by-products. The present work considers pine nut shells from a candy factory in relation to microwave processing into solid and gaseous fuels. The aim is to study the features of pine nut shells microwave pyrolysis, including the initiation mechanism and process behaviour, as well as the composition and characteristics of the resulting products. The study included experimentation in combination with application of high-speed video recording of the process and gas analysis, study of dielectric characteristics of raw materials, proximate and ultimate analysis of the obtained solid and gaseous products. At microwave pyrolysis, the conversion degree into liquid and gaseous products (76.9%) is much higher than, for example, at slow fixed bed pyrolysis (65.5%). The radiation absorption by the sample is nonlinear throughout the process and increases during the organic part degradation with the appearance of liquid and gaseous products. The gas obtained at microwave processing has a low ballast (share of CO 2 =3.5%) and a high hydrogen content (share of H 2 =19.3%) that results in a high heat of combustion (21.8 MJ·m−3), which is probably connected with interaction of pyrogenetic water and fuel carbon during plasma-chemical reactions. • Microwave pyrolysis of pine nut shells is caused by electric discharges. • Microwave radiation absorption by pine nut by shells is nonlinear over process time. • Microwave radiation absorption grows with increasing the yield of volatile products. • Interaction of pyrogenetic water and carbonaceous residue leads to high H 2 content. • Pyrolysis gas has a high heat of combustion (21.8 MJ·m–3) and low CO 2 content (< 3.5%). [ABSTRACT FROM AUTHOR]

Fossil fuels-related environmental issues, such as global climate change and soil and water acidification, are driving countries to develop biomass energy sources. As a second-generation biofuel with a significant spatiotemporal availability for global consumption, Ganoderma lucidum (GL) calls for the characterization and multi-objective optimization of its pyrolytic performance and byproducts. The GL pyrolysis was divided into three stages, with the main stage occurring between 205 and 630 °C. The activation energy for the main stage was estimated at 221.23 kJ/mol and 222.83 kJ/mol according to the FWO and KAS methods, respectively. The primary volatile products of the GL pyrolysis between 200 and 600 °C included H 2 O, CH 4 , CO 2 , CO, C O, C-O(H), C C, and NH 3. The multi-objective optimization indicated that the GL pyrolysis between 650 and 750 oC jointly led to maximum energy yield and minimum gas emission. Biochar produced from GL (GLB) between 400 and 600 °C enhanced its aromaticity and stabilized the functional groups in the carbon structure. GLB obtained exhibited an increased number of porous structures and decreased aromaticity. These results provide a theoretical and practical basis for enhancing and volarizing the comprehensive circularity of GL biomass. [Display omitted] • The pyrolysis behavior of GL was characterized through thermogravimetric analysis. • The activation energy for the main stage was based on the FWO and KAS methods. • The gaseous products and emission patterns were identified and quantified. • The production and properties of GL-derived biochar were explored. • A multi-objective optimization of energy yield and gas emissions was employed. [ABSTRACT FROM AUTHOR]

This overview addresses the formation of solid trash and the various forms of waste from a variety of industries, which environmentalists have embraced. The paper investigates the negative effects on the environment caused by unsustainable management of municipal solid trash as well as the opportunities presented by the formal system. This examination looks at the origins of solid waste as well as the typical treatment methods. Pyrolysis methods, feedstock pyrolysis, and lignocellulosic biomass pyrolysis were highlighted. Explain in detail the various thermochemical processes that take place during the pyrolysis of biomass. Due to its carbon content, low cost, accessibility, ubiquitousness, renewable nature, and environmental friendliness, biomass waste is a unique biochar precursor. This study looks at the different types of biomass waste that are available for treating wastewater. This study discussed a wide variety of reactors. Adsorption is the standard method that is used the most frequently to remove hazardous organic, dye, and inorganic pollutants from wastewater. These pollutants cause damage to the environment and water supplies, thus it is important to remove them. Adsorption is both simple and inexpensive to utilize. Temperature-dependent conversions explain the kinetic theories of biomaterial biochemical degradation. This article presents a review that explains how pyrolytic breakdown char materials can be used to reduce pollution and improve environmental management. [Display omitted] • Sources, synthesis and modification techniques of biochar are discussed. • Conversion of biomass into energy is more effective after being torrefied. • Appraisals on the activation energies during biochar preparation are made. • Torrefied biomass has environmental applications which are critically surveyed. [ABSTRACT FROM AUTHOR]

On-farm feedstocks such as grass silage and cattle slurry present recalcitrant characteristics that can limit microbial conversion in biofuel production. Introducing a biochar supplement in two-stage anaerobic digestion may facilitate feedstock hydrolysis and improve energy yields in biohydrogen and biomethane production. The biomethane potentials were first investigated in batch trials without biochar supplement; results indicated a biomethane yield of 230 L per kilogram (kg) volatile solid (VS) in single-stage digestion and 275 L/kg VS in two-stage digestion. In continuous trials, operated at an organic loading rate of 4.0 g VS/L/d, the second-stage digester in two-stage digestion showed a methane yield of 237 L/kg VS with 10 g/L biochar addition; this was 7% higher than the second-stage digester without biochar addition. At the same loading rate of 4.0 g VS/L/d, the biomethane yield in continuous single-stage digestion with 10 g/L biochar addition was 212 L/kg VS; this was 3% higher than the single-stage digester without biochar addition. Biochar was found to enhance the hydrolysis of recalcitrant solid components in the hydrogen-producing phase, promote biomethane production in methanogenesis, and stabilize the digestion process. The highest energy yield of 8.5 MJ hydrogen and methane per kg VS was achieved in the two-stage digestion with 10 g/L biochar addition at a loading rate of 4.0 g VS/L/d. The results demonstrated that the application of a biochar supplement could effectively enhance gaseous biofuel production in two-stage anaerobic digestion. [Display omitted] • Co-digestion of silage and cattle slurry was compared in single and two stage. • Biochar enhanced hydrolysis and acidification in continuous two-stage process. • 10 g/L biochar enhanced CH 4 production and stabilized continuous digestion process. • Two-stage digestion increased H 2 and CH 4 production as compared to single stage. • The highest energy yield was 8.5 MJ/kg VS at 4.0 g VS/L/d in second-stage digestion. [ABSTRACT FROM AUTHOR]

This work investigates the feasibility of extracting biofuels from general wastes, with significant non-recyclable and inorganic components, through the novel thermo-catalytic reforming (TCR®) technology. Two forms of general waste (Up-Sieve Material and Grey Compost) supplied by Risorse Ambiente Palermo (RAP) are studied. Each feedstock is shredded, pelletised and characterised. Analyses of the feedstock materials show the Up-Sieve Material has a higher heating value (HHV) of 17.6 MJ kg−1 with an ash content of 19.60% (by weight), while the Grey Compost has a HHV of 11.5 MJ kg−1 and an ash content of 40.16%. The results of the TCR® experiments on both feedstock materials show they can be thermochemically converted into energy carriers in significant quantities. The characterisation results of the oil and char from the Up-Sieve Material show they have HHVs of 38.2 MJ kg−1 and 13.6 MJ kg−1 respectively, while the oil and char from the Grey compost have HHVs of 37.0 MJ kg−1 and 5.7 MJ kg−1 respectively. In addition, the biogases produced from both feedstock materials are rich in hydrogen (up to 30% by volume each). Hence, apart from the chars and the reaction product water, the products can be further processed into biofuels due to their fuel-grade properties. Therefore, the successful extraction of biofuels from general waste is an important step in renewable energy harnessing, waste management and environmental protection. • Thermo-catalytic reforming involves intermediate pyrolysis and catalytic reforming • General waste converted to biofuels using this technology • Two types of general waste studied: up-sieve material and grey compost • Both produce biochars with high ash contents and biooils with high heating values • Both produce biogases with high hydrogen fractions, compared to gasification and pyrolysis [ABSTRACT FROM AUTHOR]

The versatility of several N-doped biochar-supported metal catalysts (M/N-BioC) derived from vineyard pruning waste, to promote circular bioeconomy, was evaluated in catalytic transfer hydrogenation (CTH) of furfural (FF), electrocatalytic oxygen reduction and evolution reactions (ORR and OER). The CTH of FF to prepare high valuable chemicals was performed in the presence of formic acid as hydrogen donor at 160 °C, reaching high conversion (up to 80 %) and selectivities towards furfuryl alcohol (ca. 88 %), establishing a promising catalytic route to valorise a biomass platform molecule using 3d-transition metal-based catalysts in absence of molecular hydrogen. The prepared materials also demonstrated moderate ORR electrocatalytic performance in alkaline medium with diffusion-limiting current densities between − 3.48 (Co/N-BioC) and − 1.27 mA cm−2 (Cu/N-BioC) and potential onset values of 0.88 ≥ E onset ≥ 0.66 V vs. RHE. Additionally, the materials tested showed selectivity towards indirect pathway in which O 2 is reduced to H 2 O 2 and then further reduced to water with the number of electrons transferred per O 2 molecule ranging from 2.1 to 3.6 electrons. The materials also presented moderate OER electrocatalytic performances in alkaline medium, with overpotential values between 0.48 (Co/N-BioC) and 0.63 V vs. RHE (Fe/N-BioC) and maximum current densities between 0.28 (BioC) and 42.60 mA cm−2 (Co/N-BioC). This research contributes to the development of a new type of promising (electro)catalyst based on biomass residue for biomass valorisation and energy conversion as a promising contribute to the future of biorefineries implementation. [Display omitted] • Novel metal-supported N-doped biochar catalysts obtained from vineyard pruning waste (VPW). • Selective production of the industrially valuable furfuryl alcohol from furfural without external H 2. • Metal-supported N-doped biochar were successfully applied as ORR and OER ECs. • (Electro)catalysts from VPW for biomass valorisation and energy conversion for future biorefineries. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new technique was developed to measure the kinetics of fast pyrolysis up to 380 K/s. • The decomposition activation energy was greatly reduced in fast pyrolysis conditions. • TGA-derived kinetic parameters failed to represent the fast pyrolysis process. • Fast pyrolysis enhanced bio-oil products by minimizing secondary reactions. • Fast pyrolysis slightly increased pore volume and surface area of biochar product. Converting algal biomass to clean energy via a thermochemical pathway is an emerging technique for tackling environment and energy issues. Traditional kinetic studies on biomass pyrolysis employ a thermogravimetric analyzer (TGA) which heats the biomass sample at a rate of 0 ∼ 2 K s−1, so TGA could only replicate the thermal behavior of the biomass sample in a fixed bed reactor. However, biomass samples can be heated at a rate over ∼102 K s−1 in industrial reactors, including fluidized beds, spouted beds, or rotary kilns due to the direct contact between biomass samples and the solid heat carriers, thus TGA is incapable to reproduce these thermal behaviors. In view of the limitation of TGA in fast heating cases, this study has developed a fast-heating thermo-balance consisting of wire-mesh and wireless power supply technique to investigate the kinetics of fast pyrolysis. Seaweed is fast-growing and can be considered a promising feedstock for biofuel production. Therefore, this study selected seaweed as representative biomass waste and compared the pyrolysis behaviors under both slow and fast pyrolysis conditions. A key finding was the TGA-derived kinetic parameters were unable to describe the pyrolysis rate under fast pyrolysis conditions with significant overestimation. When compared to slow pyrolysis, fast pyrolysis can increase bio-oil yield by about 3–17%, but the N- and S-containing compounds in the bio-oil increase by about 1.1% and 0.15% respectively at a final temperature of 700 °C. Fast pyrolysis produced about 16–53% more CO 2 than slow pyrolysis above a final temperature of 500 °C. The polarity of compounds in biochar was reduced with increasing temperature and the presence of CaO was only found in biochar at a high temperature of 700 °C. The specific surface area of biochar was higher under fast heating pyrolysis (5.534–7.469 m2 g−1) than that under slow heating pyrolysis (4.076–6.414 m2 g−1). [ABSTRACT FROM AUTHOR]

• Co-pyrolysis is an eco-friendly sewage sludge treatment process. • Mixing co-feed biomass with sewage sludge reduced the environmental burden. • All examined scenarios reduced the global warming potential. • All scenarios achieved positive energy balance with product energy recovery. • Transportation distance significantly affects scenarios' environmental outcome. To address the gaps in current research on sewage sludge (SS) pyrolysis, this study examined the feasibility of the environmental and energy demands of co-pyrolysis as an SS treatment process. The analyses included a cradle-to-gate life cycle assessment, carbon emission and credit assessment, energy recovery calculations, and sensitivity analysis. Sawdust (SD) and wheat straw (WS) were chosen as co-feeds for the co-pyrolysis scenarios; four mixing ratios (20, 40, 60, and 80 wt%) were examined for each co-feed. The functional unit was 1000 kg of bio-oil. Mixing the co-feed biomass with SS reduced the overall environmental burden by 58–83 %; WS/SS co-pyrolysis performed better than SD/SS in this respect. All examined scenarios reduced the global warming potential (GWP) and achieved a net positive energy balance; SD/SS co-pyrolysis was more desirable owing to high energy recovery. The additional gas turbine operation generated a process energy demand of 23–224 %. GWP and terrestrial ecotoxicity potential are indicators that are significantly affected by co-feed material transportation. Sensitivity analysis revealed that the transportation of feedstock and pyrolysis products should be prioritised to limit the environmental burden of the process. Co-pyrolysis is an eco-friendly SS treatment method, and its economic viability should be further investigated. [ABSTRACT FROM AUTHOR]

It is a thorny issue to properly handle heavy metals-contaminated livestock manure. The transformation of the heavy-metals-contaminated livestock manure into valuable carbonaceous material has motivated our curiosity. Herein, this study provided a new concept of valorizing the contaminated manure into heavy metals-containing biochar catalysts for catalytic fast pyrolysis/gasification of biomass to manufacture phenols-enriched biofuel and H 2 -rich gas. The versatile Cu, Pb, and Zn-containing cow manure biochar catalysts were newly prepared from Cu, Pb, and Zn-contaminated livestock manure through a single-step energy-efficient thermal process. Cu and Pb-containing biochar catalysts prepared at 500 °C were more favorable for the production of bio-oil and organic phase, and up to 41.20% of phenolics was found in the bio-oil by using the Pb-containing biochar catalyst. The highest gas yield (51.55 wt%), equaling to 550 NmL/g WS , was observed in the presence of Cu-containing biochar catalyst prepared at 500 °C. Meanwhile, the H 2 concentration was elevated to 35.85 vol%, and the H 2 yield was correspondingly promoted to 197 NmL/g WS. Additionally, a deep knowledge of the reaction mechanisms regarding the catalytic fast pyrolysis/gasification of biomass over heavy metals-containing biochar catalysts was elucidated. Overall, this study provided a novel way to valorize heavy metals-contaminated livestock manure into effective biochar catalysts for catalytic fast pyrolysis/gasification of biomass to produce phenols-enriched bio-fuel or H 2 -rich gas. [Display omitted] • A new concept of valorizing heavy metals-contaminated manure into biochar catalysts. • Cu, Pb, and Zn-containing manure biochar catalysts were prepared at 500 °C and 800 °C. • Pb/CMBC-500 and Cu/CMBC-500 favored the production of bio-oils and liquid organics. • Up to 41.20% of selectivity toward phenolics was obtained by using Pb/CMBC-500. • The highest gas yield (51.55 wt%), i.e., 550 NmL/g WS , was gained over Cu/CMBC-500. [ABSTRACT FROM AUTHOR]

Two different pathways for utilizing Miscanthus giganteus biochar were evaluated, namely, for the production of sustainable solid biofuels and as a precursor of high surface area activated carbons. Biochars were produced through a simple thermochemical conversion method via pyrolysis at 400, 500, 600, and 800 °C. The obtained biochars and raw biomass were characterized in detailed by proximate and ultimate analyses. The thermal behaviour and structural and strength properties were evaluated. The chemical composition (cellulose, hemicellulose, and lignin content) of raw Miscanthus giganteus was investigated. The biochars afforded a sufficient higher heating value (HHV) of up to 32 MJ kg−1. Activated carbon was obtained via chemical activation with KOH at 800 °C. The effect of the pyrolysis temperature on the surface properties of the activated carbons was investigated over a wide temperature range. The resulting activated carbons were characterised by N 2 adsorption–desorption at −196 °C and by determining the pH of aqueous extracts. As a potential application, the obtained activated carbon series was used for the adsorptive removal of isoproturon from aqueous media. The adsorption capacity was as high as 384 mg g−1 and depended on the pore size distribution of the activated carbons. The conducted study follows the current trend of search for novel energy sources and water purification. [Display omitted] • Miscanthus giganteus biochar was produced by pyrolysis at 400–800 °C. • Pyrolysis temperature affected properties of biochar and activated carbon. • The higher heating value of biochar pyrolysed at 600 °C was 32.8 MJ kg−1. • Biochar was used as precursor of activated carbon with high specific surface area. • Activated carbon efficiently adsorbed isoproturon from aqueous solution. [ABSTRACT FROM AUTHOR]

Severe environmental and ecological problems have resulted due to the unharvested Miscanthus lutarioriparius biomass in Dongting Lake, the largest miscanthus production hub in the world. Pyrolyzing the miscanthus biomass to produce biochar is a win–win strategy for abandoned miscanthus biomass utilization and Cd-polluted paddy restoration in Hunan. However, the sorption efficiency of biochar requires improvement by modification. It is theoretically possible that biological modification by fungi and bacteria as well as a modification technique using Fe will increase the Cd sorption capacity. Thus, the current study used two biomass biomodification techniques, FB (fungal decomposition) and BB (bacterial digestion), and one biochar Fe-modification technique (by NH 3 ·H 2 O–FeCl 3), and determined their ability to improve biochar quality. The results showed that the biomass modification by FB and BB increased the Cd sorption capacity of the derived biochar. The Cd sorption capacity of FB-derived biochar (36.4 mg g−1) was significantly greater as compared to BB-derived biochar (30.2 mg g−1) and the unmodified control (14.8 mg g−1). This improvement can be further optimized by Fe-modification, with an average potential of 22.2% (13.5–32.3%). The increased Cd sorption capacity is attributed to (in descending order of importance) the increased amount of ash, specific surface area, amount of alkaline functional groups and phenolic hydroxyl groups, and the pH of the biochar after modification. The Fe-FB-derived biochar pyrolyzed under 650 °C was tested and exhibited the highest Cd sorption capacity, at 64.9 mg g−1. Biomodification of M. lutarioriparius biomass and its subsequent pyrolysis to produce biochar will simultaneously provide economic and ecological benefits. This approach provides a model for the integrated production of food and energy from biomass. [Display omitted] • Biomass modification strongly increases the Cd sorption capacity of biochar. • Fungal decomposition and bacterial digestion are effective modification techniques. • The Cd sorption capacity of biochar can be further optimized by Fe modification. [ABSTRACT FROM AUTHOR]

Renewable energy sources such as biomass have been proven to be one of the promising sustainable alternatives to fossil fuels. However, using biomass directly as a fuel is less attractive due to its high moisture content, poor grindability, low bulk density, and low energy density nature. Hence biomass can be converted into biochar to overcome these challenges. In this study, biochar was derived from citrus peels biomass by slow pyrolysis over the temperature range of 300–700 °C. The effect of pyrolysis temperature on the quality of citrus peels-derived biochar was examined based on the physical and chemical properties obtained from various analyses. The citrus peels biomass and biochar were characterized by means of higher heating value (HHV) analysis, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX), Fourier transform infrared ray (FTIR) analysis, proximate and thermogravimetric analysis. Based on the characterization results, the potential usage of the derived biochar as a solid fuel was discussed. Results obtained from the pyrolysis experiments indicated that a lower pyrolysis temperature produced a higher char yield. The carbon content and energy content of biochar were found to be increasing with pyrolysis temperature. Biochar produced at 500 °C presented the best fuel properties by having the highest value of HHV and carbon content. The results from this study provided great insights into biomass waste reutilisation to generate value-added biochar for renewable energy production in Malaysia. [Display omitted] • Promising potential for citrus peels biomass to biochar for energy conversion. • Higher heating value of citrus peels biochar comparable to sub-bituminous coal. • Carbon and energy content increased with increasing pyrolysis temperature. • Better combustion stability for biochar of higher pyrolysis temperature. [ABSTRACT FROM AUTHOR]

Effective management and utilization of food waste and agricultural crop residues are highly crucial to mitigate the challenges of greenhouse gas generation upon natural decomposition and waste accumulation. Conversion of biogenic wastes to biofuels and bioproducts can address the energy crisis and promote environmental remediation. This study was focused on exploring the characteristics of food waste and agricultural crop residues (e.g., canola hull and oar hull) to determine their candidacy for slow pyrolysis to produce biochar and bio-oil. Process parameters of slow pyrolysis such as temperature, reaction time and heating rate were optimized to obtain maximum biochar yields. Maximum biochar yield of 28.4 wt% was recorded at optimized temperature, heating rate and reaction time of 600 °C, 5 °C/min and 60 min, respectively. Furthermore, the physicochemical, spectroscopic and microscopic characterization of biochar, bio-oil and gases were performed. The carbon content and thermal stability of biochar were found to increase at higher temperatures. Moreover, bio-oil generated at higher temperatures showed the presence of phenolics and aromatic compounds. [Display omitted] • Process optimization for slow pyrolysis of food waste, canola hull, and oat hull. • Highest yield of biochar obtained at 600 °C with 5 °C/min heating rate in 60 min. • Biochar yields at optimized conditions: food waste (28.4 wt%) < canola hull (28.8 wt%) < oat hull (29.1 wt%). • Calorific values of food waste biochar: 300 °C (20.5 MJ/kg) < 400 °C (21.2 MJ/kg) < 500 °C (22 MJ/kg) < 600 °C (22.3 MJ/kg). • Biochar at high temperature showed greater thermal stability and aromaticity of carbon. [ABSTRACT FROM AUTHOR]

The objective of this study was the full characterization of pruning residue from macrophyte Cyperus giganteus from tertiary wastewater treatment plant (WTP), Ponte dos Leites, located in Araruama, RJ, Brazil. Analyses aimed to systematically assess the feasibility of using the pruning residues as an energy resource. To do so, macrophytes were submitted to experimental analyses of their physical properties (real density: 0.44–0.77 g cm−3, bulk density: 0.08–0.09 g cm−3, among other characteristics), chemical and proximate analyses, and thermal analysis. Results of thermal behavior characterized the biomass as a viable energy source (high heat value, 14–16 MJ kg−1). C. giganteus different samples fractions analyses confirmed that molecular structures of the macrophyte (lignin: 17.3–26.8 wt %, cellulose: 27.8–32.6 wt %, hemicellulose: 30.1–31.5 wt %; depending on the plant part) affect thermal decomposition behavior. Maximum mass losses ranged from 83.43 to 75.91%. Energy production potential from biomass pruning residues generated at Ponte dos Leites was estimated to be around 92,400 MJ mês−1. This shows the effectiveness of using pruning residues biomass from macrophyte Cyperus giganteus for energy production, highlighting its energy potential, and support its use as inputs in thermal conversion processes. [Display omitted] • Physical-chemical characterization of Cyperus giganteus pruning residues from CW. • Assessment of C. giganteus biomass thermal properties (TGA, LHV, HHV and UHV). • Potential use of C. giganteus biomass for bioenergy production (biochar). • Potential use of biochar from C. giganteus biomass for agricultural purposes. [ABSTRACT FROM AUTHOR]

The depletion of fossil fuels as well as the greenhouse gas emissions from fossil fuel use have led to growing interest in biofuel production from biomass. A new technology, thermo-catalytic reforming (TCR), is one of the contributing interests. TCR technology integrates intermediate pyrolysis with a post-reforming stage to convert biomass into a high-quality bio-oil, biochar, and syngas. In this study, experiments were carried out using three Alberta-based biomass feedstocks – hardwood pellets, softwood pellets, and chips – in a 2 kg h−1 laboratory-scale TCR plant. The results show that the composition of the biomass has little effect on product yield and quality. The TCR gases had a higher heating value of 12.5–12.8 MJ kg−1 and a hydrogen content of 13–15 vol %. The produced TCR bio-oil had low water content (~5 wt %) and a heating value of 32–34 MJ kg−1. The high quality of the bio-oil is reflected in the low O/C ratio of 0.15 and TAN of 6–15 mg KOH g−1. The TCR biochar from all three feedstocks had a high heating value and a high carbon content, as well as low O/C and H/C ratios. A parametric study was conducted for the softwood pellets to observe the effect of reformer temperature (500–700 °C) and reactor temperature (400–550 °C). It was observed that at a reformer temperature of 700 °C, the gas yield increases at the expense of a reduction in bio-oil and biochar. The optimum reactor temperature for the TCR of softwood pellets was found to be 500 °C, in terms of both bio-oil quality and yield. • Thermo-catalytic reforming (TCR) technology incorporates intermediate pyrolysis with high temperature reforming. • The TCR bio-oil had low TAN (6–15 mg KOH/g), and high HHV (32–34 MJ kg−1). • The TCR gases had a hydrogen content of 13–15 vol % and HHV of 12–14 MJ kg−1. • Higher reforming temperature led to increase in gases at the expense of bio-oil. [ABSTRACT FROM AUTHOR]