Lignocellulosic Biomass

Bioethanol production from lignocellulosic biomass (LCB) has been demonstrated as alternative to conventional fuel, as it is considered to be renewable and clean energy. The major problem of bioethanol is the availability of biomass materials for its production. This review paper aims to provide an overview of the recent developments and potential regarding production techniques, ethanol yields, and properties, as well as the effects of bioethanol fuel as replacement for fossil fuel. The literature indicates that the best results have been obtained with cellulase and β-glucanase cocktail which significantly increases bioethanol production compared to fermented acid pretreatment. The classification of pretreatment, hydrolysis, and fermentation have significant effects on physico-chemical properties of bioethanol fuel, which also influence the internal combustion engines. Difference in operating conditions and physico-chemical properties of bioethanol fuels, may change the combustion behaviors and sometimes makes it difficult to analyze the fundamentals of how it affects emissions.

Bioethanol production from lignocellulosic biomass (LCB) has been demonstrated
as alternative to conventional fuel, as it is considered to be renewable and clean energy.
The major problem of bioethanol is the availability of biomass materials for its
production. This review paper aims to provide an overview of the recent developments
and potential regarding production techniques, ethanol yields, and properties, as well
as the effects of bioethanol fuel as replacement for fossil fuel. The literature indicates
that the best results have been obtained with cellulase and β-glucanase cocktail which
significantly increases bioethanol production compared to fermented acid
pretreatment

Lignocellulosic ethanol has been proposed as a green alternative to fossil fuels for many decades. However, commercialization of lignocellulosic ethanol faces major hurdles including pretreatment, efficient sugar release and fermentation. Several processes were developed to overcome these challenges e.g. simultaneous saccharification and fermentation (SSF). This review highlights the various ethanol production processes with their advantages and shortcomings. Recent technologies such as singlepot biorefineries, combined bioprocessing, and bioenergy systems with carbon capture are promising. However, these technologies have a lower technology readiness level (TRL), implying that additional efforts are necessary before being evaluated for commercial availability. Solving energy needs is not only a technological solution and interlinkage of various factors needs to be assessed beyond technology development.

This study aimed to develop an energy-and resource-efficient process for the coproduction of edible mushroom, fermentable sugar and solid biofuel from wood residues. A promising potential was revealed for wood ear fungus (Auricularia auricular-judae), which yielded about 200 g mushroom per kg dry birch-based substrate, with concomitant degradation of 76.8 and 85.7% of lignin and xylan, respectively, in the substrate. Substrate pasteurisation by hot-air (85e100 C) was as effective as by energy intensive autoclaving (121 C), resulting comparable mushroom growth and degradation of lignocellulose. The spent mushroom substrate (SMS) contained 28e33% glucan, which upon analytical enzymatic sacchar-ification released around 46% of the potentially-achievable glucose, corresponding to a 2.3efold enzy-matic digestibility compared with that of the raw substrate. The solid leftover generated after enzymatic hydrolysis revealed high thermal energy value and promising combustion characteristics, showing a plausibility to be recycled as solid fuel for self-supporting energy system and space heating.

Biomass pretreatment (BP) plays a crucial role in a lignocellulose feedstock-based biorefinery (LCFBR) for processing of three major output streams (cellulose, hemicelluloses and lignin) into chemicals and biofuels. BP includes processing of lignocellulosic material (LCM) under aqueous, dilute acid or alkaline media to obtain a cellulosic fraction, which is then fermented to produce bioethanol. Hemicellulose is usually treated as a secondary stream due to lack of efficient fermentation of hemicellulosic sugars to ethanol. This review provides BPs assuming that hemicellulose stream should be integrated in LCFBR as a primary fraction for converting into value-added compounds other than bioethanol. Different LCM treatments are analyzed foreseeing bio-based products possible to obtain from hemicellulose path.

Bioethanol production from lignocellulosic biomass (LCB) has been demonstrated as alternative to conventional fuel, as it is considered to be renewable and clean energy. The major problem of bioethanol is the availability of biomass materials for its production. This review paper aims to provide an overview of the recent developments and potential regarding production techniques, ethanol yields, and properties, as well as the effects of bioethanol fuel as replacement for fossil fuel. The literature indicates that the best results have been obtained with cellulase and β-glucanase cocktail which significantly increases bioethanol production compared to fermented acid pretreatment. The classification of pretreatment, hydrolysis, and fermentation have significant effects on physico-chemical properties of bioethanol fuel, which also influence the internal combustion engines. Difference in operating conditions and physico-chemical properties of bioethanol fuels, may change the combustion ...

The potential of using the biomass of four wetland plant species (Iris pseudacorus, Juncus effusus, Phragmites australis and Typha latifolia) grown in treatment wetland systems and under natural conditions were tested to produce high-value materials using hydro-thermal liquefaction (HTL). The results show that the wetland plants biomass is suitable for biocrude and biochar production regardless of the origin. The hydrothermal liquefaction products’ (biocrude, biochar, aqueous and gaseous phase) yields vary according with the specific biomass composition of the species. Furthermore, the results show that the biomass composition can be affected by the growing condition (treatment wetland or natural unpolluted conditions) of the plants. None of the single components seems to have a determinant effect on the biocrude yields, which reached around 30% for all the analyzed plants. On the contrary, the biochar yields seem to be affected by the composition of the biomass, obtaining different...

In this paper, we describe an experimental study on the hot alkali extraction of hemicelluloses from wheat straw and corn stalks, two of the most common lignocellulosic biomass constituents in Romania. The chemical compositions of the raw materials were determined analytically, and the relevant chemical components were cellulose, hemicelluloses, lignin, and ash. Using the response surface methodology, the optimum values of the hot alkaline extraction parameters, i.e., time, temperature, and NaOH concentration, were identified and experimentally validated. The physicochemical characterization of the isolated hemicelluloses was performed using HPLC, FTIR, TG, DTG, and 1H-NMR spectroscopy. The main hemicellulose components identified experimentally were xylan, arabinan, and glucan. The study emphasizes that both corn stalks and wheat straw are suitable as raw materials for hemicellulose extraction, highlighting the advantages of alkaline pretreatments and showing that optimization meth...

Bioethanol production from lignocellulosic biomass (LCB) has been demonstrated as alternative to conventional fuel, asit is considered to be renewable and clean energy. The major problem of bioethanol is the availability of biomass materials for its production. This review paper aims to provide an overview of the recent developments and potential regarding production techniques, ethanol yields, and properties, as well as the effects of bioethanol fuel as replacement for fossil fuel. The literature indicates that the best results have been obtained with cellulase and β-glucanase cocktail which significantly increases bioethanol production compared to fermented acid pretreatment. The classification of pretreatment, hydrolysis, and fermentation have significant effects on physico-chemical properties of bioethanol fuel, which also influence the internal combustion engines. Dif erence in operating conditions and physico-chemical properties of bioethanol fuels, may change the combustion behaviors and sometimes makes it dif icult to analyze the fundamentals of how it affects emissions.

Water hyacinth biomass is a potential substrate for the production of ethanol which can be conveniently used as a gasoline additive as an octane booster and improve the vehicle emissions. The present study is focused on isolating and screening indigenous fungi for the hydrolysis of water hyacinth in the lignocellulosic conversion process. The initial cellulose activity was measured as ICMC (carboxymethyl cellulose) index which was found to be max at pH=5. Crude enzymes extracted after solid state fermentation (SSF) in an effort to reduce the cost of ethanol production, which needs lesser infrastructure and relatively less skilled manpower besides being able to use cheaper raw materials for enzyme production. The cellulytic and xylanytic activity was monitored using water hyacinth as substrate. Out of several isolates screened, best result was recorded up to 131.995 mg/g of reducing sugar and xylose yield up to 210.4 mg/g of WHB. Concentrated enzymatic hydrolysate of WHB containing r...

Biomass burning events produce significant amounts of particulate matter which influence global radiative forcing, decrease air quality and visibility, and have negative health impacts. The quantity, size distribution, and volatility of biomass burning aerosol emissions are influenced by the combustion mode and ensuing dilution process of the emissions mixing into ambient air. This work examined the emissions from lignocellulosic biomass and its major constituents under laboratory pyrolysis conditions to understand biomass composition and dilution temperature influences on aerosol formation. The major constituents of lignocellulosic biomass, hemicellulose (xylan), cellulose and lignin, were pyrolyzed and the resultant aerosol emissions were characterized in terms of size-resolved number and mass emission factors under variable dilution temperatures. The aerosol emissions formed from biomass constituents were then compared to those of pine and corn stover, and a summative model for predicting characteristics of biomass burning emissions from the behavior of individual constituents was assessed. Results showed a significant influence of dilution temperature on particle size, number, and distribution, with the nucleation mode of particle formation dominating. The summative model performed well in predicting particle number formation from lignocellulosic biomass, but highlighted the effect of uncertainty on predicting particle mass formation.