Camalote Grass (Paspalum fasciculatum Willd) as a Sustainable Raw Material for the Production of Lignocellulosic Ethanol

The current trend of replacing a percentage of gasoline with ethanol has promoted the development of new processes for its production from lignocellulosic biomass. This work reports the production of ethanol from the Camalote grass (Paspalum fasciculatum Willd). The lignocellulosic biomass was subjected to acid hydrolysis at 125C and 15 psi with H2SO4 concentrations at 5%, 10%, and 20%, obtaining an average of reducing sugars (pentoses and hexoses) from the hydrolyzed juice with 12.3%, 10%, and 17% Brix, respectively. The sugars were fermented using yeast of the Saccharomyces cerevisiae at 30C for 48 hours. Finally, the ethanol was distilled at 78C, and the average yields were obtained through analysis of variance with a 95% confidence level. The values indicate that there is a significant difference (p > 0.05), the Tukey study shows that all the % v/v averages are different from each other. For H2SO4 concentration at 5% (10.33 ± 2), H2SO4 at 10% (9.33 ± 1.8), and H2SO4 at 20% (6.33 ± 2). The acidity analysis for the ethanol obtained from each treatment gave a value of 1.8 mg/L of acetic acid in all cases.

Lignocellulosic biomass as sustainable feedstock and materials for power generation and energy storage

Lignocellulosic biomass has attracted great interest in recent years for energy production due to its renewability and carbon-neutral nature.There are various ways to convert lignocellulose to gaseous,liquid and solid fuels via thermochemical,chemical or biological approaches.Typical biomass derived fuels include syngas,bio-gas,bio-oil,bioethanol and biochar,all of which could be used as fuels for furnace,engine,turbine or fuel cells.Direct biomass fuel cells mediated by various electron carriers provide a new direction of lignocellulose conversion.Various metal and non-metal based carriers have been screened for mediating the electron transfer from biomass to oxygen thus generating electricity.The power density of direct biomass fuel cells can be over 100 mW cm^(-2),which shows promise for practical applications.Lignocellulose and its isolated components,primarily cellulose and lignin,have also been paid considerable attention as sustainable carbonaceous materials for preparation of electrodes for supercapacitors,lithium-ion batteries and lithium-sulfur batteries.In this paper,we have provided a state-of-the-art review on the research progress of lignocellulosic biomass as feedstock and materials for power generation and energy storage focusing on the chemistry aspects of the processes.It was recommended that process integration should be performed to reduce the cost for thermochemical and biological conversion of lignocellulose to biofuels,while efforts should be made to increase efficiency and improve the properties for biomass fuelled fuel cells and biomass derived electrodes for energy storage.

Effects of protein and lignin on cellulose and xylan anaylses of lignocellulosic biomass

Interactions of lignocellulosic components during fiber analysis were investigated using the highly adopted compositional analysis procedure from the National Renewable Energy Laboratory（NREL）,USA.Synthetic feedstock samples were used to study the effects of lignin/protein,cellulose/protein,and xylan/protein interaction on carbohydrate analysis.Disregarding structural influence in the synthetic samples,lignin and protein components were the most significant（P〈0.05）factors on cellulose analysis.Measured xylan was consistent and unaffected by content variation throughout the synthetic analysis.Validation of the observed relationships from synthetic feedstocks was fulfilled using real lignocellulosic feedstocks：corn stover,poplar,and alfalfa,in which similar results have been obtained,excluding cellulose analysis of poplar under higher protein content and xylan analysis of alfalfa under higher protein content.The results elucidated that according to their protein and lignin contents of different lignocellulosic materials,accuracy of the NREL method on cellulose and xylan analyses could be improved by applying a stronger extraction step to replace water/ethanol extraction.

A Review of Lignocellulosic Biomass Pretreatment Technologies

Lignocellulose is the most abundant renewable resource on earth.However,owing to the tightly entangled structural characteristics,it is challenging to convert lignocellulose into bio-based products in the biorefinery process without pretreatment.Pretreatment can destroy the natural resistance structure of lignocellulosic biomass,which is conducive to its downstream enzymatic saccharification and fermentation process.Physical,chemical,and physicochemical pretreatments have been widely conducted for lignocellulosic biomass;several updated approaches and peculiar chemicals have also been proposed for these pretreatment methods in the recent years.Hence,this study comprehensively reviews the novel technologies and chemicals that were applied in the various pretreatments.In addition,the mechanisms,advantages,and disadvantages of the updated pretreatments are discussed to provide a reference for developing new pretreatment methods.

Production of Benzoic Acid through Catalytic Transformation of Renewable Lignocellulosic Biomass

In the present work, we reported a novel route for the conversion of lignocellulosic biomass （sawdust） to a high-value chemical of benzoic acid under atmospheric pressure. The trans- formation involved the catalytic pyrolysis of sawdust into aromatics, the decomposition of heavier alkylaromatics to toluene, and the liquid-phase oxidation of toluene-rich aromatics to benzoic acid. The production of the desired benzoic acid from the sawdust-derived aro- matics, with the benzoic acid selectivity of 85.1 C-mol% and nearly complete conversion of toluene, was achieved using the MnO2/NHPI catalyst at 100 ℃ for 5 h. The in uence of adding methanol on the catalytic conversion of sawdust to the core intermediate of toluene was also investigated in detail.

Literature Review on Furfural Production from Lignocellulosic Biomass

The use of renewable sources for obtainment of chemicals, biofuels, materials and energy has become each time larger due to environmental, political and economical problems of non-renewable energies utilization. Among several products that can be obtained from lignocellulosic biomass, which is a renewable source, there is furfural, a chemical from which many other value added chemical products can be obtained. The main route for furfural production consists of an acid hydrolysis of hemicelluloses present in lignocellulosic biomass to obtain xylose, which goes through a dehydration reaction to produce furfural. Due to the presence of an aldehyde group and a conjugated system of double bounds, furfural can go through several reactions, allowing the production of a range of value added products. In this sense, this article performs a review about mechanisms of furfural production from lignocellulosic biomass, highlighting its chemical properties which enable its utilization in different industrial applications of economic interest.

Transcriptome Analysis of White-Rot Fungi in Response to Lignocellulose or Lignocellulose-Derived Material Using RNA Sequencing Technology

White-rot fungi are the only organisms that can completely degrade all components of lignocellulosic biomass, including the recalcitrant lignin polymer. Lignin degradation is important for the industrial application of lignocellulosic biomass as a raw material for producing value-added chemicals and materials. Therefore, elucidating the lignin degradation mechanism in white-rot fungi will help researchers develop efficient and eco-friendly methods enabling the production of value-added chemicals from lignocellulosic biomass. A transcriptome analysis is an effective way to compare gene expression patterns between different samples under diverse conditions and can provide insights into biological processes. The democratization of next-generation sequencing technology, especially RNA-sequencing, has made transcriptome sequencing and analysis a common research approach for many laboratories. In this review, we focus on the transcriptome profiles of two well-characterized white-rot fungi (Phanerochaete chrysosporium and Dichomitus squalens) in response to various lignocellulosic materials. The application of RNA-seq technology combining with other techniques remains the best approach for investigating fungal secretomes and elucidating the mechanisms of fungal responses to lignocellulose.

Scientific Articles and Patent Applications on Biodiesel Production from Lignocellulosic Biomass

This document was conducted to identify trends in research activity (published articles) and technology (patent applications) on the production of biodiesel from lignocellulosic biomass. The Web of Science, Compendex, and Scopus databases were used to retrieve articles and Derwent Innovation was used to search for patent applications;300 articles and 169 patent applications were retrieved. The most common research goals (microbial lipid production, acid pretreatment, and pyrolysis) were identified from an analysis of the author’s keywords. The countries most involved in research are China (96 articles), United States (68), and India (19). The top countries in international partnerships research were United States (22), China (16), and Germany (11). Bioresource Technology (54), Biotechnology for Biofuels (18), and Green Chemistry (13) are the journals with the most published articles. United States (84) is the leader on patent applications, followed by China (15) and Japan (5).

Biotechnological Transformation of Lignocellulosic Biomass in to Industrial Products: An Overview

Lignocellulose—a major component of biomass available on earth is a renewable and abundantly available with great potential for bioconversion to value-added bio-products. The review aims at physio-chemical features of lignocellulosic biomass and composition of different lignocellulosic materials. This work is an overview about the conversion of lignocellulosic biomass into bio-energy products such as bio-ethanol, 1-butanol, bio-methane, bio-hydrogen, organic acids including citric acid, succinic acid and lactic acid, microbial polysaccharides, single cell protein and xylitol. The biotechnological aspect of bio-transformation of lignocelluloses research and its future prospects are also discussed.

Co-digestion of Waste Coffee and Cocoa Hulls: Modeling of Biogas Production by the Particle Swarm Method

Energy is a crucial material for the development of our economy.Access to sufficient energy remains a major concern for developing countries,particularly those in sub-Saharan Africa.The major challenge lies in access to clean,environmentally friendly,quality and low-cost energy in different households in our municipalities.To cope with this vast energy gap,many households are dependent on fossil fuels.In Cameroon,the consumption of wood for the supply of energy is increasing by 4%per year.Overall,approximately 80%of households in Cameroon depend on woody biomass as the sole main source of energy supply in Cameroon and demand is growing over time.In view of the climatic variations that our countries,particularly Cameroon,undergo through deforestation,the use of wood as a source of energy is expensive and harmful to the environment,hence the urgency of replacing wood with renewable energy.Biogas is one of the most versatile sources of renewable energy.On an industrial scale,it is important to automate the process control.The main objective of the present work is to model the anaerobic digestion of coffee and cocoa hulls using the particle swarm optimisation method.Pretreatment using the organosolv process was done.This resulted in 48%lignin removal and 22%cellulose increase.For the pretreated biomass,the maximum production rate was 21 NmLCH4 per day with a biomethane yield of 90 NmLCH4/gVS.This represents an enhancement of 117%in biomethane yield.A positive flammability test was recorded after the 10th day of retention time.Moreover,the data collected during anaerobic digestion allowed implementation of a two-phase mathematical model.The thirteen parameters of the model were estimated with particle swarm optimisation method in Matlab.The model was able to simulate the biomethane production kinetics and variation of volatile fatty acid concentration.

Hydrothermal liquefaction of biomass for jet fuel precursors:A review

Climate change is an important issue facing the world today and carbon reduction has become the fo-cus of attention for all countries.Alternative bio-fuels are an important means to achieve carbon emis-sion reduction.The production of jet fuel precursors from biomass by hydrothermal liquefaction(HTL)has received a lot of attention due to its mild conditions and environmental friendliness.Lignocellulosic biomass and algal biomass are considered as the second and the third generation biomasses as promising raw materials for alternative fuel preparation.Among them,lignocellulosic biomass has been extensively studied due to its wide range of sources and can be divided into one-step HTL and stepwise HTL accord-ing to the process method.Algal biomass has been extensively studied experimentally due to its short growth cycle and the fact that it can sequester large amounts of carbon without taking up arable land.In this paper,the feedstock composition of different biomasses is reviewed for the HTL of biomass.A detailed review of the process characteristics,reaction pathways and influencing factors for the HTL pro-duction of jet fuel precursors from lignocellulosic biomass and algal biomass is also presented.Theoretical references are provided for further process optimization and bio-crude quality upgrading.

Research advances on the consolidated bioprocessing of lignocellulosic biomass

Lignocellulosic biomass is an abundant and renewable bioresource for the production of biofuels and biochem-ical products.The classical biorefinery process for lignocellulosic degradation and conversion comprises three stages,i.e.,pretreatment,enzymatic saccharification,and fermentation.However,the complicated pretreatment process,high cost of cellulase production,and insufficient production performance of fermentation strains have restricted the industrialization of biorefinery.Consolidated bioprocessing(CBP)technology combines the pro-cess of enzyme production,enzymatic saccharification,and fermentation in a single bioreactor using a specific microorganism or a consortium of microbes and represents another approach worth exploring for the production of chemicals from lignocellulosic biomass.The present review summarizes the progress made in research of CBP technology for lignocellulosic biomass conversion.In this review,different CBP strategies in lignocellulose biore-finery are reviewed,including CBP with natural lignocellulose-degrading microorganisms as the chassis,CBP with biosynthetic microorganisms as the chassis,and CBP with microbial co-culturing systems.This review provides new perspectives and insights on the utilization of low-cost feedstock lignocellulosic biomass for production of biochemicals.

Pretreatment of Corn Stover Using Supercritical CO2 with Water-Ethanol as Co-solvent

Supercritical carbon dioxide,with water-ethanol as co-solvent,was applied to pretreat corn stover to enhance its enzymatic hydrolysis.The efficiency of pretreatment was evaluated by the final reducing sugar yield obtained from the enzymatic hydrolysis of cellulose.Under the operation conditions of pretreatment pressure 15 MPa,temperature 180 ℃ and time 1 h,the optimal sugar yield of 77.8℅ was obtained.Scanning electron microscopy(SEM) and chemical composition analysis were applied to the pretreated corn stover.The results showed that the surface morphology and microscopic structure of pretreated corn stover were greatly changed.After the pretreatment,the contents of hemicellulose and lignin were reduced obviously.Thus more cellulose was exposed,increasing the sugar yield.

Selective ligninolysis of wheat straw and wood chips by the white-rot fungus Lentinula edodes and its influence on in vitro rumen degradability

Background： The present work investigated the influence of lignin content and composition in the fungal treatment of lignocellulosic biomass in order to improve rumen degradability. Wheat straw and wood chips,differing in lignin composition, were treated with Lentinula edodes for 0, 2, 4, 8 and 12 wk and the changes occurring during fungal degradation were analyzed using pyrolysis-gas chromatography-mass spectrometry and detergent fiber analysis.Results： L. edodes preferentially degraded lignin, with only limited cellulose degradation, in wheat straw and wood chips, leaving a substrate enriched in cellulose. Syringyl（S）-lignin units were preferentially degraded than guaiacyl（G）-lignin units, resulting in a decreased S/G ratio. A decreasing S/G ratio（wheat straw： r =-0.72, wood chips： r =-0.75） and selective lignin degradation（wheat straw： r =-0.69, wood chips： r =-0.88） were correlated with in vitro gas production（IVGP）, a good indicator for rumen degradability.Conclusions： L. edodes treatment increased the IVGP of wheat straw and wood chips. Effects on IVGP were similar for wheat straw and wood chips indicating that lignin content and 3D-structure of cell walls influence in vitro rumen degradability more than lignin composition.

The effect of particle size and amount of inoculum on fungal treatment of wheat straw and wood chips

Background： The aim of this study was to optimize the fungal treatment of lignocellulosic biomass by stimulating the colonization. Wheat straw and wood chips were treated with Ceriporiopsis subvermispora and Lentinula edodes with various amounts of colonized millet grains（0.5, 1.5 or 3.0 % per g of wet weight of substrate） added to the substrates. Also, wheat straw and wood chips were chopped to either 0.5 or 2 cm.Effectiveness of the fungal treatment after 0, 2, 4, 6, or 8 wk of incubation was determined by changes in chemical composition, in vitro gas production（IVGP） as a measure for rumen degradability, and ergosterol content as a measure of fungal biomass.Results： Incomplete colonization was observed for C. subvermispora treated wheat straw and L. edodes treated wood chips. The different particle sizes and amounts of inoculum tested, had no significant effects on the chemical composition and the IVGP of C. subvermispora treated wood chips. Particle size did influence L.edodes treatment of wheat straw. The L. edodes treatment of 2 cm wheat straw resulted in a more selective delignification and a higher IVGP than the smaller particles. Addition of 1.5 % or 3 % L. edodes inoculum to wheat straw resulted in more selective delignification and a higher IVGP than addition of 0.5 % inoculum.Conclusion： Particle size and amount of inoculum did not have an effect on C. subvermispora treatment of wood chips. At least 1.5 % L. edodes colonized millet grains should be added to 2 cm wheat straw to result in an increased IVGP and acid detergent lignin（ADL） degradation.

Effects of formaldehyde on fermentable sugars production in the low-cost pretreatment of corn stalk based on ionic liquids

Low cost processing of lignocellulosic biomass is of great importance for sustainable chemistry and engineering.Herein,a low cost system composed of 1-butyl-3-methylimidazolium chloride([C_(4)C_(1) im]Cl),HCl and formaldehyde(FA)was developed for the pretreatment of corn stalk at 80℃.The efficiency of this technology was compared with that in dioxane system or without FA addition.Due to FA stabilization,the extent of acid-hydrolysis of carbohydrate fraction can be significantly decreased while 70%above of lignin was removed with the pretreatment of[C_(4)C_(1) im]Cl/HCl/FA system at 80℃for 2 h.A maximum reducing sugar yield of 93.7%and glucose concentration of 7.0 mg·ml^(-1) were subsequently obtained from enzymatic hydrolysis of the slurry.There were great differences in compositions of small molecule degraded products obtained with FA addition or not.The present[C_(4)C_(1) im]C_(l) based system exhibits great potential of substituting volatile organic solvents(i.e.dioxane)in developing low cost lignocellulosic biomass pretreatment at low temperature.Also,this work would gain insight into understanding on the roles of stabilization methods on the economic improvement of IL based biomass processing.

Pyrolysis of Banana and Coffee Residues after Acid Hydrolysis

The use of the residues from renewable feedstock, besides the production of fuels, but also for the generation of other chemicals products, has become a priority. Superior plants have considerable potential as carbohydrate, aryl and fatty acids sources. However, the separation of the main constituents of the samples is necessary for several purposes in the biorefinery concept. The acid hydrolysis and pyrolysis processes are very promising technology, however, some adjustments in the conditions of pyrolysis are needed for different biomasses since carbohydrates were detected （14%-17%） in the residues after the conventional acid hydrolysis of these uncommon biomasses （coffee husk and banana stem and stalk）. On the other hand, it was showed that, by pyrolysis, it is possible to obtain from the solid residue after acid hydrolysis： pyrogenic carbon （charcoal with a yield of 48.5%-52.7%） for agriculture use （biochar） and valuable chemicals in the pyrolysis oil biooil fraction （that accounted by 26.4%-29.0%, free of water）, such as lignin monomers （32.6%-56.4% of the bio-oil） and fatty acids （30%-52.5%）.

Effect of Different Pretreatment Methods on Enzymatic Saccharification and Ethanol Production from Sugarcane Shoots and Leaves

Sugarcane shoots and leaves consist of 35.2% cellulose, 23.43% hemicellulose, 12.6% lignin and 6.59% ash on dry solid （DS） basis and have the potential to serve as low cost feedstocks for ethanol production. To improve the enzymatic digestibility of these biomass and bioethanol production, three pretreatment methods had been investigated and compared, including： （1） 2% w/v NaOH solution autoclaving pretreatment; （2） 2% w/v H2SO4 solution autoclaving pretreatment and （3） two steps of 2% w/v NaOH solution autoclaving followed by 2% w/v H2SO4 solution autoclaving pretreatment. Among them, the best result for ethanol production was obtained when 15 g DS of sugarcane shoots and leaves was pretreated by using two step of 2% w/v NaOH solution autoclaving followed by 2% w/v H2SO4 solution autoclaving. The highest ethanol concentration 30.40 g/L （92.65% in fermentation efficiency） was obtained from reducing sugar 89.25 g/L at 48 h. Moreover, the washing step of solid residue after pretreatment could reduce furfural and hydroxymethylfurfural （HMF） in all pretreatment methods when compared to unwashing solid residue after pretreatment.

Literature Review on Biorefinery Processes Integrated to the Pulp Industry

Biorefinery is a new term to designate two main subjects, bioproducts and bioenergy, which play important roles towards a more bio-based society. This paper reviews the current biorefineries model as well as its future importance focusing on pulp mill opportunities. There are currently several different levels of integration in biorefineries which add to their sustainability, both economically and environmentally. Enzymatic pretreatment for biomass deconstruction aiming to release the polysaccharides is a key technology in the future biorefineries and it is currently the subject of intensive research.