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Abstract The combined effect of anions of ionic liquids (IL) and anti-solvents on pre-treatment and dissolution mechanisms of biomass are not well studied. To reveal the above effect, three different ionic liquids composed with fixed cation ([EMIM]+) but varied anions were studied for Miscanthus dissolution. Results showed that [EMIM]+[Ac]– was very good in altering the cellulose structure and crystallinity followed by enzymatic digestibility with a sugar yield of 0.98 (g/g of cellulose). The IL [EMIM]+[HSO 4 ]– was very efficient to remove lignin and partially solubilize hemicellulose, however, the sugar yield was low (0.43 g/g of cellulose) compared with [EMIM]+[MeSO 3 ]– and even the untreated Miscanthus. The regenerated biomass with water-acetone mixture (1:1 v/v) as anti-solvent resulted in higher glucose yield. The hydrogen bond basicity (β value) correlated well with cellulose crystallinity, lignin removal, and glucose yield. Graphical abstract Image 1 Highlights • [EMIM]+[Ac]– drastically decreased the cellulose crystallinity of Miscanthus. • [EMIM]+[HSO 4 ]– solubilized almost entire amount of lignin present in Miscanthus. • Enzymatic digestibility is very high for [EMIM]+[Ac]– pretreated biomass. • Glucose yield increased with water-acetone mixture (1:1 v/v) as anti-solvent. • β value related well with crystallinity index, lignin removal and glucose yield. [ABSTRACT FROM AUTHOR]

Areca nut husk is the most promising alternative source of low-cost raw materials because it contains a considerable amount of five-carbon monosaccharide sugar in the form of xylose. This polymeric sugar can be isolated and transformed into a value-added chemical using fermentation. To extract sugars from areca nut husk fibers, preliminary pretreatment, such as dilute acid hydrolysis (H2SO4), was performed. The hemicellulosic hydrolysate of areca nut husk can produce xylitol through fermentation, but toxic components inhibit the growth of microorganisms. To overcome this, a series of detoxification treatments, including pH adjustment, activated charcoal, and ion exchange resin, were carried out to reduce the concentration of inhibitors in the hydrolysate. This study reports a remarkable 99% removal of inhibitors in the hemicellulosic hydrolysate. Subsequently, a fermentation process using Candida tropicalis (MTCC6192) was executed with the detoxified hemicellulosic hydrolysate of areca nut husk, yielding an optimum xylitol yield of 0.66 g/g. This study concludes that detoxification techniques like pH adjustment, activated charcoal, and ion exchange resins are the most economical and effective methods for eliminating toxic compounds in hemicellulosic hydrolysates. Therefore, the medium derived after detoxification from areca nut hydrolysate may be considered to have significant potential for xylitol production. [ABSTRACT FROM AUTHOR]

• Dahlia flower is an abundant and low-cost biological resource. • XRF analysis confirmed the presence of useful compounds. • Kinetic and thermodynamic parameters were calculated to understand its pyrolysis behavior. • Pyrolysis experiments were performed in Py-GC–MS at multiple temperatures. • Py-GC–MS analysis confirmed formation of higher amount of hydrocarbons at 550 °C. To explore the bioenergy potential, kinetic and pyrolysis behavior of waste dahlia flowers (DF), model-free methods and Py-GC–MS were used. Kinetic characteristics of DF biomass were estimated by adopting four model-free methods, Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), Friedman, and Distributed Activation Energy (DAEM). Further, functional groups, the presence of mineral matter in DF biomass, and mineral compounds present in the inorganic residue were analyzed using FTIR, EDX, and XRF. Physicochemical analysis results confirmed its bioenergy potential for conversion into renewable fuel and valuable chemicals. The kinetic results of DF biomass showed that activation energy varied with conversion value, and the thermodynamic analysis indicated multiple step pyrolysis. FTIR analysis confirmed the presence of hemicellulose, cellulose, and lignin in biomass. EDX and XRF analysis also revealed the presence of various useful mineral matter, which had a positive effect during pyrolysis. Py-GC–MS results confirmed that at a lower temperature (500 °C), the formation of ester, nitrogen containing compounds and acid were higher, while at higher temperatures (550 °C and 600 °C), the formation of oxygenated compounds were reduced and the production of hydrocarbons and alcohols increased. [ABSTRACT FROM AUTHOR]

Utilizing lignocellulosic biomass as a renewable energy source for the production of sustainable fuel is of paramount importance. This study focuses on the catalytic co-pyrolysis of Mesua ferrea L. de-oiled cake (MDC) and Garlic husk (GH) as potential feedstocks for bio-fuel production. The pyrolysis experiments were conducted using a semi-batch reactor under inert conditions at temperatures of 500, 550, and 600 °C, with a heating rate of 10 °C min−1, a particle size below 1 mm, and an inert gas flow rate of 80 mL min−1. The findings reveal that temperature significantly influences the yield of pyrolytic products. However, GC-MS analysis detected higher oxygenated compounds in the bio-oil, negatively impacting its heating value. To improve fuel quality, co-pyrolysis with and without a catalyst for a feedstock ratio of 1:1 w/w was performed. Red mud, an alkaline waste mainly composed of Fe2O3, Al2O3, and SiO2, is a hazardous environmental concern from aluminum production and is used as a catalyst. The red-mud catalysts reduced oxygen concentration and increased carbon content, acidity, and heating value in the pyrolytic oil. GC-MS analysis of the bio-oil confirmed that using catalysts combined with MDC and GH significantly decreased the concentration of acidic and aromatic compounds, thereby improving the pyrolytic oil's higher heating value (HHV). [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Production of simultaneous hydrogen and ethanol from ultrasound pre-treated lignocellulose biomass (Ziziphus rugosa). • The process parameters are optimized using Taguchi method of optimization of multi responses. • The optimal factors for both ethanol and hydrogen production using fluidized bed bioreactor was temperature 40 °C, pH 5.5 and OLR 50 g L−1. • Optimum yield of both ethanol and bio hydrogen were found to be 0.21 mol, and 30.8 ± 0.5 mmol respectively. Lignocellulosic ethanol is one of the utmost promising and happening technological options available to moderate greenhouse gas emissions from transportation sector. Present study used ultrasound-assisted lime pretreated lignocellulosic biomass of Bon bogori for saccharification to obtain fermentable sugar. The saccharification process yielded 6.89% sugar. The fermentation study was conducted using wastewater sludge as a source of microorganisms to produce bio-ethanol and bio-hydrogen. The study includes optimization of fermentation process using Taguchi methodology (multi response). Four important parameters such as type of reactors (stirred tank and fluidized bed reactor), temperature, pH of operation and organic loading ratio were considered for optimization process. The optimum production of both ethanol and bio-hydrogen were found to be 0.21 mol, and 30.8 ± 0.5-mmol respectively. [ABSTRACT FROM AUTHOR]

Thermogravimetric analysis of three lignocellulosic biomass such as Miscanthus grass, Castor stem, and Jatropha stem under high purity nitrogen atmosphere were carried out over a temperature range of 25 °C-900 °C at three different heating rates of 10, 15, 20 °C min-1. The profiles generated from thermal decomposition process signified that except dehydration there were three main stages of degradation occurred associated with three main components (hemicellulose, cellulose, lignin). The temperature peaks at maximum weight loss rate obtained from Differential thermogravimetric thermograms changed with increasing heating rate. The activation energy and pre-exponential factor were calculated by applying two model-free methods and compared. The kinetic parameters obtained from Kissinger and Ozawa methods were in good agreement with the experimental results. The value of kinetic parameters explained the thermal stability of the biomass. The thermal analysis could not infer the composition and chemical structure of lignocellulosic biomass; hence FTIR spectroscopic analysis has been carried out. [ABSTRACT FROM AUTHOR]

• Hydro-deoxynation of pyrolytic oil has been reviewed. • Bio-oil stability parameters are studied and discussed in-depth. • Techn-economic analysis (TEA) of Hydro-deoxynation of pyrolytic oil is reviewed. • The influence of reactors types on HDO of pyroltic oil is also discussed. • HDO of pyrolysis oil is a feasible technology from the economic point of view. The rapid depletion of fossil fuels and environmental concerns have led researchers to explore alternative sources of energy. Pyrolytic oil derived from biomass is considered to be a potential alternative to fossil fuels, but it lacks certain physicochemical properties that make it unsuitable to be used as fuel. For instance, the high oxygen content in the pyrolytic oil exhibits chemical instability, the tendency to polymerize, and low energy density compared to traditional fuels. The hydrodeoxygenation (HDO) method is a viable technique to enhance the desirable characteristics of pyrolytic oil for commercial applications. This method has the disadvantage of catalyst deactivation owed due to coking, and its extent depends on the nature of oxy-compounds, catalyst type, and experimental conditions. However, by varying the experimental parameters such as catalyst acidity, temperature, pressure, solvent, and reaction time, the HDO product characteristics may be tailored to meet the specific requirements and applications. In this work, we have presented a comprehensive review of multiple alternatives to produce pyrolytic oil with essential fuel characteristics. The techno-economic analysis (TEA) and kinetic analysis of the pyrolytic oil were also elaborated. Overall, the review paper highlights the influence of process variables, kinetics investigation, reactor types and techno-economic analysis of HDO. [ABSTRACT FROM AUTHOR]

Pre-treatment of biomass is a preordained phase for the fragmentation of lignocellulosic biomass to its basic constituents such as lignin and carbohydrate molecules. Existing pre-treatment technologies can extract the desirable chemicals from biomass, however, the choice of biomass is a challenge. The present study worked on husk generated after removing the nut from Areca fruit. The husks are the by-product resulting from the cultivation of Areca nut fruit. The present study focused on the comparison of biochemical characterization of this organic waste biomass before and after the acid and alkali pre-treatment process. Characterization includes thermogravimetric analysis (TGA), Fourier transform infra-red spectroscopy (FTIR), and quantitative analysis of extractives. The present study revealed that the Areca husk fiber contained 29.17% hemicellulose which can be explored as a low-cost source of xylose. [ABSTRACT FROM AUTHOR]

Fuels derived from biomass are renewable as well as environment friendly. In this study, three biomasses viz. husk of areca nut ( Areca catheu), trunks of moj ( Albizzia lucida), and bon bogori ( Ziziphus rugosus) available in North-East region of India were tested as potential biofuel sources. The accentuation of this study was to determine the kinetic parameters using thermogravimetric (TG) technique under air and nitrogen atmosphere. The experiments were carried out within temperature range 300-973 K under air and nitrogen atmosphere at four different heating rates viz. 5, 10, 15, and 20 K min, respectively. The mass losses at different lumps in the TG graphs were estimated. The first-order kinetic parameters such as activation energy and pre-exponential factor were calculated for different reaction zones for all the three biomass samples. Effects of atmosphere on combustion characteristics (e.g., peak temperature, ignition temperature, and reactivity index) of biomasses were also determined in this study. Areca nut husk has highest ignition temperature (526.38 K) and reactivity index (0.21) but moj has highest peak temperature (597.91 K) along with highest activation energy (348.04 kJ mol) and pre-exponential factor (1.12 × 10 min), respectively. [ABSTRACT FROM AUTHOR]

Abstract: The lignocellulosic materials are cheap and readily available either in the form of agricultural waste or forest residues. These materials can be used as a source for energy production either in the gaseous form (CO, H2 etc) or in liquid form (ethanol, butanol etc) to meet the rising demand of energy. The reign of lignocellulosic materials for energy production is a proven fact in this era of energy research. The present study focuses on characterization of three biomass samples namely areca nut husk (Areca catheu), moj (Albizia lucida) and bonbogori (Ziziphus rugosa), available in the region of North-East India. Physical and chemical analysis of these lignocellulosic biomass samples were performed using X-ray diffraction techniques, thermogravimetric analysis, FTIR, Raman spectroscopy and CHNSO analysis. Maximum crystalinity was observed in areca nut husk fiber (63.84%) followed by moj (46.43%) and bonbogori (42.46%). The calorific values of all the biomasses were found within the range of 17 MJ/kg to 22 MJ/kg. All these properties combined together per se shows that areca nut husk, bonbogori and moj are potential sources for biofuel production. [Copyright &y& Elsevier]

Pretreatment is an inevitable high energy consuming process en route to biofuel production which alters the recalcitrant structures of lignocellulosic biomass. An attempt has been made to pretreat the areca nut husk fibre using dilute sulphuric acid. The Taguchi robust design method of optimisation (L9 orthogonal array) was applied to this acid catalyzed pretreatment process. Cellulose crystallinity is directly proportional to the degree of enzymatic hydrolysis of any kind of cellulosic substrate; the present study considers it as an index to optimise the process parameters. The study showed that the sulphuric acid concentration plays the major role during the pretreatment of areca nut husk (57% contribution) followed by the duration of operation (24.98% contribution) and solid loading (14.3% contribution). The optimal factors obtained from the design of experiments were further validated using the experimental results. [ABSTRACT FROM AUTHOR]