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The valorisation of the organic fraction of municipal solid waste (OFMSW) in the circular economy context is of outmost importance. This review aimed to examine the state-of-the-art valorisation technologies of OFMSW as resource for bioethanol and biodiesel. Firstly, feedstock mapping was performed, where high fluctuation of parameters was revealed. Considering the mean values, the stoichiometries of mechanically and source-sorted OFMSW are C 22 H 44 O 28 N and C 20 H 36 O 16 N, respectively. The substrate's mean carbohydrates (50%) and lipids (13%) contents reflect its potential in bioethanol and biodiesel production, respectively. As far as bioethanol is concerned, this paper critically reviewed the existing variance of second-generation bioethanol production methodologies from OFMSW revealing that high bioethanol yields (over 80%) could be achieved if the treatment steps of pretreatment, enzymatic hydrolysis and fermentation are synergistically compiled. To this end, bioethanol yield could benefit from suitable enzymatic blends. Furthermore, this paper discussed about different ways of oil extraction from OFMSW and various biodiesel production techniques. Soxhlet extraction combined with alkaline transesterification emerged as the most widely applied biodiesel production line from OFMSW. The novelty of this literature review lies in the integration of both bioethanol and biodiesel production processes, in a biorefinery concept that would allow the production of both biofuels along with that of biogas. This integration scenario rendered an energy efficiency expressed as energy content in products per energy in raw materials equal to 68%, proving that OFMSW is a feedstock that could meet the sustainability criteria for biofuels production. Image 1 • Up to date information on the composition of OFMSW. • Bioethanol production from OFMSW; pretreatment, hydrolysis, fermentation, stillage. • Biodiesel production from OFMSW; oil extraction, transesterification. • Bioethanol, biodiesel, biogas production from OFMSW under the biorefinery concept. • Integrated biorefinery exhibits various technical and energy benefits. [ABSTRACT FROM AUTHOR]

Bioethanol is the alternative to fossil fuels for the transport sector's environmental sustainability. Scientific journals have disclosed a few works on modeling and enhancing bioethanol production processes. To industrialize these production processes, however, the modeling requires consideration for mass and heat transfer, mainly when applying intensification machinery. Consequently, CFD is preferable to a comprehensive analysis of fluids. Computational fluid dynamics (CFD) configure the flowing progress of bioethanol production, the flow pattern distribution curve, and flow pattern visualization. This article reviews recent advances in CFD Modeling of bioethanol production processes in conventional and newly designed bioethanol production technologies, such as simultaneous saccharification and fermentation (SSF) and membrane bioreactor. None of other studies addressed a kinetic model of the fermentation process in the SSF and membrane bioreactors. For the design of new (SSF) and membrane bioreactors, CFD and its combination with other simulation software might deliver a wealth of useful data. The first section of this paper addresses the bioethanol production process of the second generation: pretreatment, enzymatic saccharification, and fermentation. The second section of this review discussed hydrodynamics, reaction kinetics, and bioreactor design, focusing on CFD models of the bioethanol production technology. A conclusion and a recommendation, this section concludes with a discussion of insights into unexplored areas of study and challenges in modeling bioethanol production processes. • Industrial applications of bioethanol production processes necessitate CFD modeling. • The review provides insight into CFD modeling of bioethanol production technology, especially SSF and membrane bioreactors. • This paper considers the methods used to produce bioethanol. • Perspectives in CFD modeling of bioethanol production processes are analyzed. [ABSTRACT FROM AUTHOR]

Abstract The acid pretreatment process is the most employed technique used to disrupt the lignocellulosic matrix. Thus, this paper provides an overview of the acid pretreatment considering important aspects related to the operation conditions, yields, future improvements and the potential use to upgrade lignocellulosic biomass in energy vectors. Moreover, this paper is focused on technical and economic aspects of the use of the acid pretreatment in bioethanol production using olive tree biomass as a case study. This review will provide the framework of the acid pretreatment based on reported applications, experimental and theoretical data. The most well-studied applications of the acid pretreatment are in bioethanol and biogas production. Furthermore, this pretreatment has been improved using solid catalysts and by increasing the solids loading. These options have advantages compared to the traditional way. Even so, improvements in the technical and energy aspects must be performed to make the implementation of this process viable from an economic and environmental perspective. Instead, the kinetic modelling and statistical analysis of the acid pretreatment can be postulated as strong tools to predict the behaviour of different feedstocks under acidic conditions. Moreover, new alternatives to increase the mass and heat transfer in this process related to reactor design conform a new research field. Regarding the case study, the acid pretreatment is one of the most energy-consuming stages of bioethanol production. Low solids loadings are recommended to obtain production costs that are comparable with those reported on the industrial level. In contrast, a high solids loading allows the environmental impact of the process to be reduced in terms of liquid waste generation and carbon dioxide emissions. Finally, the acid pretreatment should be included as an effective method for the biotechnological conversion of lignocellulosic biomass to produce energy vectors once the technical, economic and environmental drawbacks have been overcome. Highlights • Energy vectors production can be improved using optimal acid pretreatment operating conditions. • Operation conditions and kinetic modelling are shown as key information of the acid pretreatment. • Solid catalyst and dry acid pretreatment can serve as alternative methods for biomass upgrading. • The impact of solids loading on the bioethanol production process is demonstrated and discussed. • Low solids loading in acid pretreatment increases the feasibility of bioethanol production. [ABSTRACT FROM AUTHOR]

The recent and rapidly growing interest in biofuel as a green energy source has raised concerns about its impact on the prices, returns and volatility of related agricultural commodities. Analyzing the spillover effects on agricultural commodities and biofuel helps commodity suppliers hedge their portfolios, and manage the risk and co-risk of their biofuel and agricultural commodities. There have been many papers concerned with analyzing crude oil and agricultural commodities separately. The purpose of this paper is to examine the volatility spillovers for spot and futures returns on bio-ethanol and related agricultural commodities, specifically corn and sugarcane. The diagonal BEKK model is used as it is the only multivariate conditional volatility model with well-established regularity conditions and known asymptotic properties. The daily data used are from 31 October 2005 to 14 January 2015. The empirical results show that, in 2 of 6 cases for the spot market, there were significant negative co-volatility spillover effects: specifically, corn on subsequent sugarcane co-volatility with corn, and sugarcane on subsequent corn co-volatility with sugarcane. In the other 4 cases, there are no significant co-volatility spillover effects. There are significant positive co-volatility spillover effects in all 6 cases, namely between corn and sugarcane, corn and ethanol, and sugarcane and ethanol, and vice-versa, for each of the three pairs of commodities. It is clear that the futures prices of bio-ethanol and the two agricultural commodities, corn and sugarcane, have stronger co-volatility spillovers than their spot price counterparts. These empirical results suggest that the bio-ethanol and agricultural commodities should be considered as viable futures products in financial portfolios for risk management. [ABSTRACT FROM AUTHOR]

Grasses as lignocellulose biomass are promising feed stocks for renewable bioethanol production, since these raw materials have high productivity, require low agricultural inputs, have positive environmental impacts, are easy to process and do not compete with the food crops. However, bioethanol production from grass biomass requires efficient pre-treatment, enzymatic hydrolysis and microbial fermentation processes which varies with types of grass species and the microorganisms used. Pretreatment is an important process for delignification of lignocellulose biomass and is dependent on the type of lignin present in the biomass and the degradation pathway employed for removal of the specific type of lignin. Further, enzymatic hydrolysis converts the cellulose and hemicellulose into monomers, making it feasible for the fermenting microorganisms to convert it into bioethanol where use of improved strain and biomass can yield higher ethanol on industrial scale. This review paper presents an overview of the types of grass species, their composition and cultivation practices, fermentation process used for bioethanol production and genetic tools used for improvement in bioethanol production from grass biomass on a sustainable basis. The current knowledge and future prospect for industrial bioethanol production from grass biomass along with its economic aspects have also been discussed in this review. [ABSTRACT FROM AUTHOR]

Lignin, which can be recycled from bioethanol and paper production wastes, is the second largest renewable resource. However, studies and applications on sustainable upgrading of lignin are extremely limited and most of them only focus on its combustion to obtain energy. The abundance of reactive groups in lignin makes it a potential feedstock for the production of sustainable low carbon footprint value-added materials. Among them, the preparation of flocculants from lignin has attracted much attention. This paper systematically reviews recent progress of low carbon footprint lignin-based flocculants. The modification methods for the production of lignin-based flocculants, Mannich, sulfonation, carboxylation, crosslinking and graft copolymerization, and the flocculation mechanisms in wastewater treatment are discussed emphatically. Moreover, the factors affecting the flocculation performance of lignin-based flocculants, including internal factors, such as charge density, molecular weight, conformation, and external factors, such as dosage, treatment time, wastewater pH, and temperature are discussed in detail, which are conducive to design, production and application of lignin-based flocculants for lower carbon footprint. Furthermore, we critically point out the current deficiencies of the lignin-based flocculants and the challenges facing commercialization, then we propose the corresponding possible solutions. The production and application of high-efficiency lignin-based flocculants are of great significance for resource conservation, low carbon footprint, and wastewater reuse. Image 1 • Lignin show environmental advantages as a sustainable feedstock. • Commonly used chemical modification methods for lignin-based flocculants. • Applications of lignin-based flocculants in treatment of various wastewaters. • Flocculation mechanism and external factors affecting the flocculant mechanism. • The challenges facing the commercialization of lignin-based flocculants. [ABSTRACT FROM AUTHOR]

It is a popular fact that the world's dependency on fossil fuel has caused unfavourable effects, including lessening crude oil reserve, decreasing air quality, rising global temperature, unpredictable weather change, and so on. As the effort to promote sustainability and independency from fossil fuel, bioethanol is now favoured as the blend or fossil petrol substitute. However, the feedstock functionality of first generation bioethanol production is restricted due to its edibleness since it would clash the feeding purpose. Second generation bioethanol production fulfils the impractical gap of first generation since it employs non-edible feedstock sourced from agriculture and forestry wastes. Lignocellulosic and starchy materials in them are convertible to fermentable sugars that are able to be further processed, resulting anhydrous bioethanol as the end product. This paper critically reviews the existing variance of second generation bioethanol production methodologies, namely pre-treatment, hydrolysis, fermentation and distillation, as well as the worth of second generation production for future reference. The discussions in this paper are also fit as the fundamental for feasible planning of second generation bioethanol production plant. [ABSTRACT FROM AUTHOR]

Abstract The production of bioethanol is growing, as it is been used as biofuel which is termed as a clean energy fuel. When ethanol is blended with gasoline, the octane number of the mixture increases and acts as an antiknock agent, besides releasing fewer pollutant emissions. To use as an automobile fuel when blended with gasoline, this ethanol should have less than 0.5 wt% of water. Therefore, ethanol has to be dehydrated; but it forms an azeotrope with water. In these scenarios, the implementation of conventional distillation technique is difficult and therefore unconventional techniques like extractive distillation have to be implemented. But this process leads to high operating costs, and hence researchers have investigated adsorption-based techniques. This methodology is not only very effective but also less expensive. The performance of the adsorption process depends on the type of adsorbent, its physical characteristics like particle and pore size, the phase in which it is carried and process parameters like temperature, initial concentration, and dosage. Thus, this paper presents a comprehensive review of the intrinsic characteristics of adsorbents, the effect of process parameters on adsorption efficiency and the influence of the phase of operation. Various types of isotherm and kinetic models utilized in the adsorption process are also presented in detail. Mathematical models describe the inherent mechanisms of the adsorption process; hence the governing equations like mass, energy and momentum balances for both liquid and gas phase are also reviewed. Graphical abstract fx1 Highlights • Dehydration of bioethanol performed using wide range of adsorbents has been reviewed. • Various physico/chemical factors and mechanisms have been critically analysed. • Isotherm and Kinetic models to describe the adsorption process are collated. • Mathematical models for description of bioethanol dehydration are reviewed. [ABSTRACT FROM AUTHOR]

Abstract Agro-industrial lignocellulosic waste, an abundant source of non-food fermentable sugars, represent a potentially negative environmental impact due to unsuitable waste disposal issues, which can be attenuated when transformed to bioethanol. Several alternative processes have been developed for bioethanol production from a large variety of agro-industrial wastes (AIW) but the high economic costs of these technologies and variable substrate composition limit their implementation at commercial scale. Nevertheless, consolidated bioprocessing to produce bioethanol of second generation has been researched increasingly in recent years and it is, so far, the most promising fermentation approach for bioethanol production. Mexico ranks as one of the leading food producing countries worldwide with 818 agro-food products, 71 of which hold the first place by production volume at international level. However, strategies and specific actions for AIW management need to be incorporated. This paper discusses agro-industrial lignocellulosic waste potentials in Mexico for efficient production of second generation bioethanol using consolidated bioprocessing. Highlights • The potential of agro-industrial waste in Mexico was discussed. • Status of 2G ethanol production in Mexico have been comprehensively reviewed. • Advances and challenges of CBP have been explained. [ABSTRACT FROM AUTHOR]

Big bluestem ( Andropogon gerardii ) is an ecologically dominant warm-season (C4) perennial native grass that comprises as much as 80% of the plant biomass in prairies in the grasslands of the North American Midwest. Ranchers adopted the species as a forage crop long ago, but its high cellulosic content and low agricultural input requirements recently have made big bluestem a promising feedstock for ethanol production and bio-oil. The objective of this paper is to review big bluestem׳s potential as a bioenergy crop with respect to both biology and conversion. Biology includes distribution and adaptation of big bluestem, ecotypes and varieties currently studied, production management, and disease and pest control. Conversion includes discussion of the conversion of big bluestem biomass to bio-ethanol and bio-oil. Estimated ethanol yield of big bluestem is about 1886 L/ha, which is comparable to previously reported herbaceous biomasses. Various constraints and potential applications of big bluestem as an energy crop are analyzed in the final section of this paper. Plant breeding research that focuses on modifying big bluestem composition to minimize recalcitrance to bioconversion and increasing biomass yields is imperative. [ABSTRACT FROM AUTHOR]

The main objective of this review paper is analyzes perspectives of manufacturing bioethanol via biotechnology, using sustainable management. Two categories are emphasized: (i) agro-industrial valuation, which represents alternative methods for bioethanol production, and (ii) Agro-industrial Techniques and Infrastructure Analysis. Future of biofuels is addressed in terms of applicability and production methods. Authors perform a systematic literature review to characterize the present state of knowledge on ethanol production. The study is conducted from a decision-making standpoint, so that they identify several problems (subcategories) in bioethanol production. The section on technology and industrial infrastructure focuses on advances in biorefineries, revealing technical and economic limitations, and also the gap between sustainable production policies and environmental impact. The second part of the paper presents the evolution of the industrial sector toward technological innovation and adoption of complex bio-production methods for clean energy production. This review mostly covers results reported over the past decade, with a special emphasis on papers published recently, from 2010 to 2021, therefore, it can serve for extended future research that would address additional specific categories. One concludes that the industrial sector must promote bioethanol production efficiently and sustainably, harmonized with the society and the environment. Sustainable production points to alternative energy sources based on cellulosic materials and third generation materials derived from algal biomass. • Chemical processes in the agro-industrial production sector include clean technologies. • Critical gaps for biofuel production contain factors that must be related to industrial processes and uncertain economic cost. • Technological integration of 1G and 2G bioethanol production can reduce operating costs and investment risks. • Biorefinery models use various biomass feedstocks, and they integrate 1st/2nd generation technological processes. [ABSTRACT FROM AUTHOR]

This paper propose the inclusion of a raw material in Brazilian fuels sector. The corn is used in other countries to produce ethanol, in Brazil has other business demands, not being employed as proposed. The work also highlights the energy, economic, social and environmental role in production ethanol from corn, especially for the country´s development, minimizing losses in logistics and grain exports. Comparatively corn is more expressive as bioenergy associated with sugarcane in the Brazilian conditions, because other raw materials have limitations: sugar beet does not have viable cultivation; rice, cassava and wheat are insufficient; and sweet sorghum requires technological adjustments to have significant production. The co-products that arise from the production of ethanol are nutritionally rich, causing less pressure on corn commodities trading. [ABSTRACT FROM AUTHOR]

The possible scarcity of oil and gas resources in the future (whether in quantity or areas of availability) is a major concern throughout the world. For this reason, governments all over the world are working on reducing their dependence on imported energy resources. Alternative energy resources such as bioethanol, biodiesel and biomass have gained prominence over the years in order to substitute petroleum-derived products. Bio-based lubricants have also gained importance as alternatives to conventional petroleum-based lubricants in various applications, especially the automotive industry. Despite the benefits of bio-based lubricants, these lubricants are still far from being practical substitutes. Since bio-based lubricants are typically produced from raw vegetable oils, these lubricants have poor cold flow properties as well as low thermo-oxidation and hydrolytic stability. However, these shortcomings can be addressed by modifying the vegetable oils chemically or incorporating additives into the oils. This review provides a detailed treatment on bio-based lubricants, the various vegetable oils used as the feedstocks for the production of bio-based lubricants, the physicochemical properties of bio-based lubricants, the processes used for chemical modification of vegetable oils, the lubrication properties of bio-based lubricants, as well as the various additives used to improve the properties of bio-based lubricants. It is believed that this review paper will provide useful insight to researchers and practioners in the field regarding bio-based lubricants. [ABSTRACT FROM AUTHOR]

Ethanol production and the diffusion of flex-fuel vehicles are successful examples of renewable energy in the transportation sector in Brazil. Despite these achievements, challenges regarding the Brazilian fleet, composed of inefficient light-duty passenger vehicles (LDPV), need to be addressed. In this regard, political measures have been implemented, for instance voluntary labeling and fiscal incentives related to fuel economy targets. However, there is still room to improve these instruments to capture greater economic and environmental benefits related to fuel economy. In this paper, we present information regarding the Brazilian LDPV fleet, its fuel consumption, its CO 2 emissions and a description of the historical evolution of policies concerning fuel economy in Brazil. Furthermore, we estimate impacts related to the adoption of mandatory fuel economy standards (MFES), in terms of fuel economy and CO 2 emissions reduction. This analysis indicates that 18,626 million liters of gasohol E-22 and 16,274 million liters of ethanol E-100 can be saved up to 2035. The related reduction of CO 2 emissions is also significant, about 62 Gg of CO 2 . [ABSTRACT FROM AUTHOR]

Brown algae adsorb a considerable amount of CO 2 and store carbon in their biomass more than many other algae species. Nowadays, depletion of fossil fuel resources, greenhouse gas emissions, climate change, and the future of human food security have encouraged scientists and policymakers to develop safer and more sustainable alternatives of energy sources. Brown algae have attracted most of this attention in North American countries to generate a wide range of products and biomass for biorefinery. In this review paper, various aspects of brown algae cultivation and its biorefinery process are discussed. Main drivers of the sectors, opportunities, challenges, and future prospects of brown algae-based biofuels in North America have been taken into account; the most appropriate processes and pathways are compared to maximize the outputs and environmental benefits, and minimize costs and drawbacks of the industry. Analysis and predictions of renewable energy future in North American countries revealed that biomass-derived fuels, including brown algae biofuels, will play an important role especially in the transportation sector. These biofuels, including bioethanol and biodiesel are accompanied by various co-products and by-products in an optimized biorefinery system to convert every available component of brown algae. However, cultivation of brown algae to produce biomass at a commercial scale with minimum costs and market demands are the main challenges of algal biofuels. Finally, expanding the value chain of the brown algae biorefinery by producing more advanced biofuels such as aviation fuels and value-added co- and by-products would significantly impact North American countries' gross domestic product. • Many studies related to biofuel production from brown algae are reviewed comprehensively. • Brown algae have attracted significant attention in North America. • Costs and markets demands are two main challenges for this algal energy. • Effective strategies for optimal production of biofuel from brown algae are provided. • Current challenges and future prospects for biofuel from brown algae are discussed. [ABSTRACT FROM AUTHOR]

Fuel security, economics and climate change issues are creating a requirement for alternative renewable fuels. Bioethanol produced by algal biomass is becoming increasingly popular all over the world due to the sustainability of feed stock and environmentally friendly nature. This review paper describes the bioethanol production technology from algae using various cultivation, harvesting, extraction and commercialization techniques and its environmental perspectives. The economic sustainability of algae-derived bioethanol biofuel depends on the cost of production that could be minimized by producing valuable secondary by-products, which is the aim of current algal biofuel research. Future technologies with sufficient potential for maximum extraction capacity and minimal downstream processing using low cost feedstock will address the cost-effectiveness of renewable bioethanol biofuel. [ABSTRACT FROM AUTHOR]

Bioethanol is an attractive biofuel having potential for energy security and environmental safety over fossil fuels. To date, numerous biomass resources have been investigated for bioethanol production, which can broadly be classified into sugars, starch and lignocellulosic biomass. However, conversion of biomass into ethanol varies considerably depending on the nature of feedstock, primarily due to the variation in biochemical composition, and so, only a few feedstocks have been exploited commercially. In recent years, the conversion process of biomass has been improved significantly, even though most of these achievements are yet to be implemented in commercial facility. All the major steps in a typical conversion process, particularly fermentation of sugars that is the common step for all biomass, are greatly influenced by microorganisms. A traditional yeast, Saccharomyces cerevisiae , and a bacterial species, Zymomonas mobilis , are widely used in the ethanol fermentation technology. Many factors affect ethanol production process, and the final yield is directly associated with the optimum conditions of these attributes. This review paper presents an overview on the first and second generation bioethanol production with a particular attention to the potential of various biomass sources, technological approaches, role of microorganisms and factors affecting ethanol production process. [ABSTRACT FROM AUTHOR]

Abstract: While biofuels have currently been regarded as a good alternative for fossil fuels, there remain many debates on their impacts on human and environment. This paper tried to shed light on bio-ethanol in Brazil as one of the main producers and exporters in the world. The main question was to understand “how sustainable is bio-ethanol production in Brazil?” To answer, the political motives of producing bio-ethanol followed by its ecological and socio-economic impacts were discussed. The paper concluded that although bio-ethanol production in Brazil seems environmentally friendly, it might socio-economically be hazardous. [Copyright &y& Elsevier]

Bioethanol is one of the most promising and eco-friendly alternatives to fossil fuels, which is produced from renewable sources. Although almost all the current fuel ethanol is generated from edible sources (sugars and starch), lignocellulosic biomass (LCB) has drawn much attention in recent times. However, the conversion efficiency as well as ethanol yield of the biomass differs greatly with respect to the source and nature of LCB, primarily due to the variation in lignocellulosic content. Two major polysaccharides in LCB, namely, cellulose and hemicellulose firmly link to lignin and form a complex lignocellulosic network, which is highly robust and recalcitrant to depolymerization. For this reason, generation of ethanol from LCB requires a complicated conversion process that has made it commercially non-competitive. As attempts to exploit LCBs into commercial ethanol production, recent research efforts have been devoted to the techno-economic improvements of the overall conversion process, in addition to screen out promising feedstocks. This review paper presents an overview on the diversity of biomass, technological approaches and microbial contribution to the conversion of LCB into ethanol. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this paper is to describe the benefits of sugar cane ethanol in Brazil, appointing the productivity of this type of fuel based on hectares of plantation, its carbon dioxide cycle and the contribution to reduce the greenhouse effect. In the following step the uses of ethanol for hydrogen production by steam reforming is analyzed and some comparison with natural gas steam reforming is performed. The sugar cane industry in Brazil, in a near future, in the hydrogen era, could be modified according to our purpose, since besides the production of sugar, and ethylic and anhydric alcohol, Brazilian sugar cane industry will also be able to produce biohydrogen. Fuel cells appear like a promising technology for energy generation. Among several technologies in the present, the PEMFC (proton exchange membrane fuel cell) is the most appropriate for vehicles application, because it combines durability, high power density, high efficiency, good response and it works at relatively low temperatures. Besides that it is easy to turn it on and off and it is able to support present vibration in vehicles. A PEMFC''s problem is the need of noble catalysts like platinum. Another problem is that CO needs to be in low concentration, requiring a more clean hydrogen to avoid fuel cell deterioration. One part of this paper was developed in Stockholm, where there are some buses within the CUTE (clean urban transport for Europe) project that has been in operation with FC since January 2004. Another part was developed in Guaratinguetá, Brazil. Brazil intends to start up a program of FC buses. As conclusion, this paper shows the economical analysis comparing buses moved by fuel cells using hydrogen by different kinds of production. Electrolyze with wind turbine, natural gas steam reforming and ethanol steam reforming. [Copyright &y& Elsevier]

Abstract: The production of bioethanol from agricultural residues such as wheat, barley, sugar cane, corn and rice in Iran is investigated in this paper. In Iran, agricultural residues are not commonly used for energy application. This paper aims to cover several perspectives on the size of the bioethanol feedstock resource in Iran. Crop residues and sugar cane bagasse are included in feedstock for production of bioethanol. There are approximately 17.86MT of wasted crops in Iran that can potentially produce 4.91GL of bioethanol per year. Wheat, sugar cane bagasse, rice, barely and corn are the most favourable bioethanol production source in Iran. Agricultural waste materials can be used for production of bioethanol fuel. Bioethanol can be considered as the optimum alternative fuel for gasoline. Bioethanol is an environmentally friendly fuel and has the potential to provide comparable engine performance results. [Copyright &y& Elsevier]

Increased environmental concern over climate change due to higher oil usage has made human being to shift to cleaner and greener alternatives. The utilization of abundant agricultural waste streams as renewable feedstock for biofuels production can be a pivotal strategy. Among others, rice is one of the most largely grown crops, and more than 4.8% of the total production goes to waste. Although previous reviews are related to biofuels obtained from some rice waste, most of those are focused on lignocellulosic rice residues with much attention to thermo-chemical processes. The present paper, instead, reviews for the first time the biotechnological approaches to convert all rice wastes, like rice husk, rice straw, broken rice, discolored rice, unripe rice, into liquid (bioethanol, biobutanol, biodiesel), and gaseous (biogas, biohydrogen) biofuels through the use of pure or mixed microbial cultures. The global availability of each rice byproduct has been also investigated and the potential of rice waste as a 'fuel farm' has been estimated for bioethanol. The physical, chemical, enzymatic, or microbial pretreatments, which play a key role in making carbon available for hydrolysis and fermentation, are here discussed and evaluated. Despite the great promise of technologies so far developed, further research is still required for their up-scale and industrial commercialization. Moreover, future process integrations will open the landscape to biorefinery schemes where rice waste streams can be processed into biofuels and other added-value products, towards the full exploitation of the feedstocks and the economic and environmental sustainability of the overall process. [Display omitted] • Rice waste has the potential to produce many gigalitres of biofuels worldwide. • Selection of pretreatment is the key to obtain the highest biofuel production. • Different biotechnological approaches for biofuel production are elucidated. • Complete rice waste valorization using a biorefinery approach is underscored. [ABSTRACT FROM AUTHOR]

Industrial technologies for bioethanol production from lignocellulosic biomass were reviewed by integrating feedstock handling, selective-fractionation, synergistic enzymatic hydrolysis, industrial fermenting yeast strains, and simultaneous saccharification and co-fermentation in this paper. The breakthrough of integrated technologies contributed to economic feasibility was also analyzed by industrial operation test. With the integrated technologies, the feedstock cost was reduced by 19.4% compared with traditional conversion process. The enzyme loading was reduced by 25.0% using synergistic enzyme systems compared with single cellulase addition. The pre-hydrolysis and simultaneous saccharification and co-fermentation without detoxification operation was developed using inhibitors-tolerant Saccharomyces cerevisiae . More than 4% (w/w) ethanol concentration was achieved, which corresponded to 72.3% theoretical yield of ethanol. The improved conversion efficiency of pentose resulted in 41% increase of ethanol yield. Additionally, lignin plastic composite material (LPCM) and compress natural gas (CNG) were co-produced, which proportioned the capital cost of process and hence facilitated the economic feasibility of process. As a result, the corresponding ethanol total cost was reduced to 5571.6 Yuan/t (Yuan, Chinese currency). In conclusion, the low cost of feedstock, simple and integrated conversion process, and multi-products production contribute to the competiveness of this integrated industrial technology for lignocellulosic bioethanol production. [ABSTRACT FROM AUTHOR]

Bioethanol fuel obtained from biomass and bioenergy crops has been proclaimed as one of the feasible alternative to gasoline fuel, as it is considered to be clean, renewable and green. In this review, the bioethanol production techniques from different lignocellulosic biomass, and its potential ethanol yield are studied. Moreover, this paper has reviewed the effects of bioethanol fuel blends on spark ignition engine combustion characteristics (i.e. cylinder pressure, cylinder temperature, flame speed, combustion efficiency, combustion duration, heat release rate, knocking and cold start); engine performance parameters (i.e. torque, brake power, brake specific fuel consumption, brake mean effective pressure, brake thermal efficiency and volumetric efficiency); and emission characteristics (i.e. carbon monoxide, oxides of nitrogen, carbon dioxide, unburned hydrocarbon and other unregulated emissions). Recently, many researchers produced bioethanol from herbaceous, industrial and municipal solid wastes (MSW) instead of agriculture and woody biomass. Most of the engine test results showed a remarkable improvement in engine performance and enhanced combustion characteristics for bioethanol fuel. In addition, the carbon monoxide and unburned hydrocarbon emissions decreased. Conversely, carbon dioxide and oxides of nitrogen emissions were not significantly reduced. Furthermore, there was no significant reduction of unregulated emissions, such as aromatics, acetaldehyde, and carbonyls. [ABSTRACT FROM AUTHOR]

Rice is the main staple food in most of the Asian countries and rice crops generate a huge amount of rice straw as crop residue in the fields. Unsustainable use of rice straw and open burning of crop in the field not only produces threat to environment by producing large amount of greenhouse gas (GHG) emission, but also make farmer׳s loose a very viable by-product. Rice straw can be used in bio-ethanol production and bring additional income and sustainable utilization. It will also provide clean energy solution to ever increasing energy demand in India. However, it becomes more important to study the sustainability of bio-ethanol production from rice straw and how it can make sense in today׳s Indian agricultural scenario. Although, the bioethanol obtained from rice straw is a carbon neutral in nature, but the concerns of environmental impacts have been raised for the whole process i.e. from rice cultivation, rice logistics, pretreatment techniques, bioethanol generation and transportation. The present review focuses on the environmental sustainability issues arising from use of rice straw for bioethanol production. The environmental impacts are assessed by studying the emission of greenhouse gases from each stage of life cycle. The paper presents an outlook on current status and future prospects of ethanol blending in the country. [ABSTRACT FROM AUTHOR]

The potential for sugarcane ethanol from Brazil to mitigate GHG emissions is undeniable, but the way that ethanol is produced during the agricultural and industrial phases will ultimately determine its benefits to society. In this paper, we evaluate the environmental impacts of sugarcane agriculture and ethanol production in Brazil as management practices continue to change and production expands to new frontiers. We focused our evaluation on the impacts on water, atmosphere, and soils, including how the application of organic and inorganic fertilizers and the accumulation of crop residue in the field affect emissions of greenhouse gases (GHG). We also addressed the impacts of land use changes on threatened biomes and discussed some of the present obstacles regarding conservation and restoration efforts. We concluded that, since a similar assessment was put forth in 2008, our knowledge about the environmental impacts of sugarcane ethanol in Brazil has advanced with regard to soil degradation, nitrogen dynamics, and soil carbon stocks. However, more information is still needed about the impacts of the increasing use of pesticides, herbicides, and fertilizers in sugarcane agriculture, especially on water resources. Furthermore, without a better understanding about how landscape fragmentation affects the biodiversity of terrestrial and aquatic tropical ecosystems and the services they provide, policies created to protect and restore them may be ineffective. On the other hand, the use of presently available scientific information to end unsustainable farming and the implementation of conservation strategies proposed by the Brazilian Forest Code could be a first step to guarantee that ethanol is produced more sustainably in Brazil. [ABSTRACT FROM AUTHOR]

This paper tests for the existence of bubbles in the ethanol–gasoline price ratio in Brazil from 2000 to 2012 using right-tailed ADF tests. Results suggest the existence of two bubbles: one which has already burst (during the re-election of President Lula); and one which has been ongoing since 2010, thus corroborating empirical and anecdotal evidence in the Brazilian sugarcane industry. Freezing gasoline prices not only depressed ethanol prices but also depressed investments in new sugarcane crops and distillation plants. [ABSTRACT FROM AUTHOR]

Fuel cell systems powered by bio-fuels such as ethanol are potential solutions to local, small scale electricity needs, especially in remote, off-grid locations. In recent years, many researchers around the world have studied the on-site autothermal reforming of ethanol to hydrogen, which can then be used in the fuel cell. However, a comprehensive review of those efforts has not been carried out. In this paper, a detailed literature review of experimental and numerical research is presented, with a focus on the catalysts, reactor design, and simulation and modelling efforts that sought to understand interactions among fluid flow, heat and mass transfer and chemical kinetics. Our review indicates that although considerable work has been carried out on the development of catalysts, relatively fewer studies report system level experiments and simulations that are necessary before these systems can be commercially deployed. Thereby, we also identify areas for further research in the area of ethanol autothtermal reforming. [ABSTRACT FROM AUTHOR]

The aim of the current paper is to discuss the sustainability aspect of biorefinery systems with focus on biomass supply chains, processing of biomass feedstocks in biorefinery platforms and sustainability assessment methodologies. From the stand point of sustainability, it is important to optimize the agricultural production system and minimize the related environmental impacts at the farming system level. These impacts are primarily related to agri-chemical inputs and the related undesired environmental emissions and to the repercussions from biomass production. At the same time, the biorefineries need a year-round supply of biomass and about 40–60% of the total operating cost of a typical biorefinery is related to the feedstocks chosen, and thus highlights on the careful prioritization of feedstocks mainly based on their economic and environmental loadings. Regarding the processing in biorefinery platforms, chemical composition of biomasses is important. Biomasses with higher concentrations of cellulose and hemicelluloses compared to lignin are preferred for bioethanol production in the lignocellulosic biorefinery, since the biodegradability of cellulose is higher than lignin. A green biorefinery platform enables the extraction of protein from grasses, producing an important alternative to importing protein sources for food products and animal feed, while also allowing processing of residues to deliver bioethanol. Currently, there are several approaches to integrate biorefinery platforms, which are aimed to enhance their economic and environmental sustainability. Regarding sustainability assessment, the complexities related to the material flows in a biorefinery and the delivery of alternative biobased products means dealing with multiple indicators in the decision-making process to enable comparisons of alternatives. Life Cycle Assessment is regarded as one of the most relevant tools to assess the environmental hotspots in the biomass supply chains, at processing stages and also to support in the prioritization of any specific biobased products and the alternatives delivered from biorefineries. [ABSTRACT FROM AUTHOR]

The rise of biofuels took place after the great oil crisis that impacted the world in the 70s. At that period, the mission of supplying the world׳s demand was given primarily to liquid biofuels. South America has a set of renewable energy sources and shows a great potential to contribute to the energy supply of the world in the coming years. Brazil leads the production of biofuels in South and Latin America since the 60s and also stands out at a global scale. Considering this context, this paper aims to approach the current scenario and the prospects of the main South-American countries, whose energy matrices receive relevant contribution from liquid biofuels. In South America, liquid biofuels stand out among renewable energies, represented mostly by ethanol and biodiesel. Brazil and Argentina lead the scenario and prospects of these biofuels in South America, while countries like Peru and Uruguay look for alternatives to supply such demands as they struggle internally for legislations that stimulate the use of biofuels in the energy matrix. [ABSTRACT FROM AUTHOR]

Ethanol production on small scale (on-farm) substantially contributes to the effort to replace fossil fuels. However, the share of small scale production remains incipient, either due to inefficiency in the process or legal restrictions on the commercialization of hydrous ethanol fuel. The aim of this paper is to justify this incipient industry by detailing the small-scale ethanol production process and presenting operational data collected in the literature from the last three decades. The reviewed data showed that the inefficiency of the process affects the economic feasibility by product losses in bagasse and vinasse or through excessive energy consumption. The feasibility of ethanol production on small scale requires addressing these technological obstacles through the integral use of co-products. [ABSTRACT FROM AUTHOR]

Indonesia has an intensive agro-industrial sector which evolves large volumes of residues each year. Currently, these residues are under-utilized and have a deleterious impact on the environment, Oil Palm Empty Fruit Bunches (OPEFBs) in particular are highly abundant and offer good potential for conversion to bioenergy and bio-based products, in particular bioethanol and xylitol (widely used as an artificial sweetener and can substitute sugar in food and pharmaceutical industries). This paper provides a comprehensive review of the techno-economic opportunities and challenges for the wider utilization of OPEFBs for the generation of bioethanol and xylitol in Indonesia. This review highlights the significant potential for the valorization of OPEFB based on resource availability in the country (828 MWe/year or 45.86 Mt/year) and growing demand for both bioethanol (from 0.22 billion L in 2019 to 10.38 billion L in 2025) and xylitol (up to 2.20 kt in 2020). Various process configurations were explored to assess the potential for simultaneous co-production of bioethanol and xylitol. A mass balance and techno-economic assessment showed that the preferred scenario was Scenario 3 (co-production of bioethanol with xylitol and lignin) and that this has the potential to generate 46,145 kL bioethanol, 7.716 kt xylitol, and 25.704 kt lignin per year. This is significant given the limited production for both bioethanol and xylitol in the country currently. Further work is required to address challenges around technical, policy and supply chains. This work provides an original and novel strategy to support the wider adoption of commercially viable bioethanol production in Indonesia. • An abundance of oil palm empty fruit bunches (OPEFB) creates prospect for biorefining. • Manufacture and supply of bioethanol and xylitol in Indonesia is feasible. • Multiple scenarios are proposed for mono- and co-production of bioethanol and xylitol. • Co-production of bioethanol and xylitol promotes sustainable bioeconomy. • Challenges remain on scalability, financial incentives and supply chain integration. [ABSTRACT FROM AUTHOR]

Abstract: The contribution of Renewable Energy Resources is vital for a country׳s economic growth by providing high efficiency in energy, as well as an effective tool for the confrontation of climate change. In particular, concerning the EU, an increase in the consumption of Renewable Energy Resources as a proportion of the total energy consumption by its member states was set as an objective until 2020. Ethanol has been widely used as a substitute to conventional energy like gasoline and oil. The present paper surveys the role of alternative energy prices and gas emissions in the formation of the ethanol prices. The results of the empirical survey confirmed the existence of a sole relationship among the variables employed. According to the results obtained, an increase in the volume of emissions or in gasoline prices results in an increase in ethanol prices while the opposite is confirmed in the case of crude oil. Τhe elasticity of ethanol prices to the increase of the emissions is another result worth mentioning, indicative of the significant role of the emissions in the formation of ethanol prices. [Copyright &y& Elsevier]

Abstract: In recent years, algae-based fuels have received a growing interest of the industry sector and the US Government as a sustainable and renewable energy source. Algae constitute a unique feedstock as they contain high levels of both lipids and sugars and, thus, can be used for both biodiesel and ethanol production successively, in a two-stage process. In addition, the production of algae-based fuels shows a low environmental footprint and high energy efficiency. Algae can produce between 10 and 100 times more oil per acre as compared with traditional oil crops (e.g., oil palm) and can also grow 20–30 times faster than food crops. The production of algae does not compete with traditional crops for fresh water, high quality soil or fertilizers and, if cultivated off-shore, algae production does not require land resources at all. Furthermore, algae-based fuel is carbon-neutral, as algae assimilate similar amounts of CO2 for its growth as is released upon fuel combustion. From the policy perspective, algae-based fuels can provide a buffer for mitigating the food/feed vs. fuel problem in the long-term. The paper analyzes and discusses very recent developments in the algae R&D from the economic, environmental and policy perspective. It presents ways for solving the economic impediments as well as prospects for the commercialization of the algae technology in the near future. It covers multiple scientific and industry-related research and experimental studies to provide a comprehensive picture of the trends and patterns in the field. [Copyright &y& Elsevier]

Abstract: Sugarcane bagasse is the residue produced by mills after juice is extracted from sugarcane. Other important solid residues in the sugarcane-to-sugar-and-ethanol production chain are the leaves and tops of the stalks (together referred to as cane trash). Although it represents a significant portion of the energy in sugarcane, cane trash is currently left in the fields. This paper has described and analyzed how residues (bagasse and cane trash) are produced from sugarcane and their use as an energy source in the production of ethanol. Also, it presents a review of the physical properties and characteristics of bagasse and cane trash and estimate their energy potential. Bagasse and cane trash have similar fuel characteristics to other biomasses fuels. Special attention should be given to the characteristics of cane trash ash, which has higher fusibility and alkali levels than bagasse. A flowchart of a typical mill was described and the thermal and mechanical energy consumption at various stages of the production process was determined. Of the energy consumed as work, about 58% is accounted for by milling and juice extraction, and 33% by the generation of electricity for use in the plant. In a typical mill using steam generators operating at average pressure and temperature (22bar, 300–360°C), about 15% of the bagasse produced is surplus, and an average of 480kg of steam is used per tonne of cane processed. An energy consumption analysis revealed that there was significant scope for reducing the amount of steam needed to operate the turbines in mills because of the low isentropic efficiencies identified. Cane trash, which is not yet used for energy production, also shows great energy potential because it is produced in similar quantities to bagasse, and its calorific value is only slightly lower. [Copyright &y& Elsevier]

Abstract: Pretreatment technologies are aimed to increase enzyme accessibility to biomass and yields of fermentable sugars. In general, pretreatment methods fall into four different categories including physical, chemical, physico-chemical, and biological. This paper comprehensively reviews the lignocellulosic wastes to bioethanol process with a focus on pretreatment methods, their mechanisms, advantages and disadvantages as well as the combinations of different pretreatment technologies. Moreover, the new advances in plant “omics” and genetic engineering approaches to increase cellulose composition, reduce cellulose crystallinity, produce hydrolases and protein modules disrupting plant cell wall substrates, and modify lignin structure in plants have also been expansively presented. [Copyright &y& Elsevier]

Abstract: Contribution to satisfying the final energy demand, the necessities arises from waste minimization, and rural area's developments are the main incentives for biofuel usage in the Iranian energy supply system. This paper develops a model for the supply chain of bioethanol and bioETBE from the farms to the end users which integrates the temporal and spatial scales. It considers the techno-economical evaluations of first and second generation biofuels. The results provide practical insights for decision makers to introduce the biofuel into the Iranian energy systems. Here, the optimal designs of transition pathways of biofuel supply chain are available which successfully assesses the benefits and barriers to the decision maker. [Copyright &y& Elsevier]

Abstract: Biodiesel has potential as a substitute for petroleum diesel because of the increasing worldwide concern for environmental sustainability and dwindling petroleum resources. Methanol has been the commonly used alcohol for biodiesel production. Compared with methanol, ethanol can be derived from sugar- and starch-based feedstocks and lignocellulosic biomass. Therefore, using ethanol as the acyl acceptor for biodiesel (fatty acid ethyl esters, FAEEs) production is drawing increasing interest in recent years. There are extensive studies using various approaches for the preparation of FAEEs and the properties of these fuels have also been explored. This paper reviews the state-of-the-art technologies for FAEE preparation. At the end, the fuel properties of FAEEs as well as the limitations and perspectives of biodiesel production with ethanol as the acyl acceptor are highlighted. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to present aspects about the energy balance of sugarcane crops and its carbon dioxide emissions. We calculate energy used in agricultural, industrial and distribution sectors by five sugarcane mills of Mato Grosso do Sul and we compare the yield with its energy delivery. The energy balance obtained, with an average 6.8, shows that is advantageous to produce ethanol in the lands of that Brazilian state. We have prepared a forecasting of electricity production from bagasse taking into account two types of technology. Finally, we present the potential value of CO2 emitted by the five mills to evaluate greenhouse gas emissions of the ethanol production valor chain. [Copyright &y& Elsevier]

Abstract: Bioethanol accounts for the majority of biofuel use worldwide, either as a fuel or a gasoline enhancer. In Serbia, the industrial production of bioethanol still relies on conventional feedstocks containing starch and sugar such as corn, wheat and molasses. In order to improve the economy of bioethanol production and to avoid the competition of the feedstock utilization for food and energy, several production approaches based on crop selection, process integration and waste utilization were considered in this paper. Particular attention was put on utilization of non conventional crops such as triticale and damaged crops not appropriate for food consumption. Potential of lignocellulosic biomass for the production of second generation ethanol in Serbia was also considered as well as the utilization of stillage as a main by-product. The investigated approaches can significantly improve the economy of bioethanol production and contribute to solve serious environmental problems. [Copyright &y& Elsevier]

Abstract: This paper aims at reviewing the life cycle assessment (LCA) literature on second generation bioethanol based on lignocellulosic biomass and at identifying issues to be resolved for good LCA practice. Reviews are carried out on respective LCA studies published over the last six years. We use the classification of lignocellulosic biomass to define system boundaries, so that the comparison among LCA results can be thoroughly assessed based on identified system components. A basis for attributing environmental burden for different biomass feedstocks is also suggested. Despite the non-homogeneous systems, we conclude that second generation bioethanol performs better than fossil fuel at least for the two most studied impact categories, net energy output and global warming. For the latter category, carbon sequestration at the biomass generation stage can even consistently offset the GHG emissions from all parts of the life cycle chains at high ethanol percentage (≥85%). The aspect of biogenic carbon and agrochemical input for energy crops and biomass residues, and the effect of removal of the latter from soil have not been treated consistently. In contrast, the exclusion of upstream chain of biomass waste feedstocks is observed in practice. The bioethanol conversion process is mostly based on simultaneous saccharification and co-fermentation, characterized by high yield and low energy input. In this regard, the LCA results tend to under estimate the real impacts of the current technology. The choice of allocation methods strongly influences the final results, particularly when economic value is used as a reference. Substitution of avoided burden seems to be the most popular allocation method in practice, followed by partition based on mass, energy, and economic values. [Copyright &y& Elsevier]

Abstract: Due to the reduction of the economic support for refined sugar efforts have been made to find new ways of using sugar beet outside food industry. This paper investigates the possibilities of introducing bioethanol co-production in Serbian sugar plants. Research shows current state of Serbian sugar industry and technical aspects of bioethanol co-production in sugar plants. These results represent important step toward mass production of bioethanol in Serbian factories. The main goals of introducing the concept of sugar and bioethanol coproduction would be efficient use of available resources for the production of energy, reduction of greenhouse gases emission, decreased dependence on import and creation of new jobs. Besides that, it would provide flexibility in terms of variation of produced quantities of sugar and ethanol, depending on the conditions prevailing on the market. [Copyright &y& Elsevier]

Abstract: China, like many other countries, is promoting the development of liquid biofuel, including bioethanol and biodiesel. The Chinese government has set biofuel development targets for the coming decade and sanctioned a series of supportive policies. This paper provides a comprehensive overview of current liquid biofuel development in China, related government policies, and the potential opportunities and challenges for its future expansion. Our assessment is based on two rounds of in-depth fieldwork and a thorough literature review. The assessment shows that the prevailing concern on food security has pushed China to move from cereal-based to non-cereal-based biofuel production. Emphasis has also been put on utilizing new marginal land for feedstock production. Our assessment indicates that the targets of China''s biofuel development are cautious and feasible, but on the other hand there are still severe challenges for the sustainability of such development. A better understanding of China''s experience in striking a balance between energy security, food security and environmental protection would inform the debates across country boundaries and contribute to the efforts for global sustainability. [Copyright &y& Elsevier]

Abstract: With industrial development growing rapidly, there is a need for environmentally sustainable energy sources. Ethanol from biomass, bioethanol, is an attractive, sustainable energy fuel source for transportation. Based on the premise that fuel bioethanol can contribute to a cleaner environment and with the implementation of environmental protection laws in many countries, demand for this fuel is increasing. Efficient ethanol production is based on optimized processes where utilization of cheap substrates is highly demanding. Utilization of different types of lignocellulosic materials can be considered for production of ethanol. Among various types of lignocellulosic substances water hyacinth (Eichhornia crassipes) is a potential resource available in many tropical regions of the world. It is a noxious aquatic weed which grows fast. A considerable amount of research work is in progress for its bioconversion into ethanol using two-sequential steps of hydrolysis and fermentation. This paper reviews the bioconversion of water hyacinth to ethanol. [Copyright &y& Elsevier]

Abstract: In the contemporary era of looming energy crunch, hydrogen fuel, obtained from ethanol, is a potentially strong contender as an energy carrier, based on a renewable source. Moreover, acknowledging the critical importance of distributed power devices and systems on one hand and the importance of microscale engineering on the other, we envisage developing an ethanol-based distributed hydrogen production device of the order of 1kW using steam reforming of ethanol (SRE). In this paper, the key issues related to this microscale distributed hydrogen production strategy are discussed in view of its potential application for polymer electrolyte membrane (PEM) fuel cells. The design challenges and issues related to various essential micro-devices, viz., the pre-heater, fuel reformer, water gas shift (WGS) reactor, carbon monoxide preferential oxidation (CO PrOX), required for efficient production of H2 with very low concentration of CO contamination, are discussed. Various production schemes are carefully evaluated for the purpose. Need for integration of micro-devices is emphasized to obtain a compact fuel processor system. [Copyright &y& Elsevier]

Abstract: A renewable biofuel economy is projected as a pathway to decrease dependence on fossil fuels as well as to reduce greenhouse gases (GHG) emissions. Ethanol produced on large-scale from lignocellulosic raw materials is considered the most potential next generation automotive fuel. In this paper, a Life Cycle Assessment model was developed to evaluate the environmental implications of the production of ethanol from five lignocellulosic materials: alfalfa stems, poplar, Ethiopian mustard, flax shives and hemp hurds and its use in passenger cars. Two ethanol-based fuel applications, E10 (a mixture of 10% ethanol and 90% gasoline by volume) and E85 (85% ethanol and 15% gasoline by volume) were assessed and the results were compared to those of conventional gasoline (CG) in an equivalent car. The environmental performance was assessed in terms of fossil fuels requirements, global warming, photochemical oxidant formation, acidification and eutrophication by means of the Life Cycle Assessment (LCA) methodology in order to identify the best environmental friendly lignocellulosic source. The results show that, compared to CG, life cycle greenhouse gases emissions are lower for etanol blends, specifically up to 145% lower for E85-fueled car derived from Ethiopian mustard. This crop is also the best option in terms of eutrophying emissions regardless the ratio of ethanol in the blend. In the remaining impact categories, other feedstocks are considered beneficial, that is, poplar in the case of photochemical oxidants formation and flax shives for acidification. Concerning fossil fuels requirements, decreases up to 10% and 63% for E10 and E85 derived from hemp hurds and Ethiopian mustard, respectively, were obtained. According to the results, the study clearly demonstrates the importance of using low intensive energy and high biomass yield crops. LCA procedure helps to identify the key areas in the ethanol production life cycle where the researchers and technicians need to work to improve the environmental performance. Technological development could help in lowering both the environmental impact and the prices of the ethanol fuels. [Copyright &y& Elsevier]

Abstract: This article aims to investigate the introduction, sustenance and consolidation of bioethanol in Brazil. It presents an analysis of its introductory stage, from the first decades of the 20th century until the early 1970s, when, in a second stage, additional measures allowed for its consolidation and maturity, under the widely known Proalcool. The paper presents a historical reinterpretation of the policies, mechanisms and instruments adopted in both stages, aiming to highlight the economical and political links. It is concluded that the interests of the agrarian elites, operating at the political level, and the fuel supply crisis during Second World War were basic during the first stage, to sustain a productive and logistic capacity and maintain ethanol alive as an automotive fuel. It is also concluded that the launching of Proalcool represented a transition combining the interests of the sugarcane agribusiness, burdened by the drop in sugar prices, and the need to equilibrate the balance of payments due to the oil shocks of the 1970s. Ethanol supply shocks harmed its credibility and its commercial consolidation was only possible through the introduction of flex-fuel vehicles with expectations strongly relying on climate change mitigation actions. [Copyright &y& Elsevier]

Abstract: This paper explores the potential for ethanol production and fuel substitution in Nepal based on established sugarcane production, installed capacity for sugar and ethanol production, economic opportunities for the national economy, and potential to reduce greenhouse gas emissions. At present conditions, 18,045m3 ethanol can be annually produced in Nepal without compromising the production of food products from sugar cane such as sugar, chaku and shakhar. The effects for the country can be manifold. As much as 14% of gasoline import reduction, and annual savings of US$ 10 million could be achieved through the introduction of the E20. The activity can provide an incentive for improved yields in sugarcane production, and help develop the industrial sector. This, in turn, will have a positive effect in terms of job and income generation in the rural areas where 85% of the population live. Improvement of agricultural practices for sugarcane could also have an indirect and positive effect on improving other agriculture activities. Furthermore, the use of ethanol in the transport sector will have a positive environmental effect while reducing CO2 emissions and combating pollution in the Kathmandu Valley. Finally, the substitution of ethanol in transport will imply lower imports of oil products and less draining of resources from the Nepalese economy. [Copyright &y& Elsevier]

Abstract: Several biofuel candidates were proposed to displace fossil fuels in order to eliminate the vulnerability of energy sector. Biodiesel and bioethanol produced from terrestrial plants have attracted the attention of the world as potential substitute. However, due to food vs. fuel competition as well as land consumption of these biofuel, they have brought much controversy and debate on their sustainability. In this respect, cultivation of macroalgae such as seaweed at sea water which does not expend arable land and fertilizers provides a possible solution for this energy issue. Carbohydrates derived from seaweeds contain hexose sugars which are suitable materials for fermentation to produce ethanol. Therefore, it is possible to produce fuel ethanol from seaweeds. The potential and prospective of seaweeds to play the role as a sustainable energy provider are demonstrated in this paper. This study offers a conceivable picture of macroalgae-based third-generation bioethanol biorefinery to stimulate the initiation of the exploration in the related field. [Copyright &y& Elsevier]

Abstract: The Autonomous Province of Vojvodina is an Autonomous Province in Serbia, containing about 27% of its total population according to the 2002 Census. Contribution of renewable energy sources in total energy consumption of Vojvodina contemporary amounts to less than 1%, apropos 280GWh/year. By combining of methods of introduction of new and renewable sources, systematic application of methods for increasing of energetic efficacy, as well as of introduction of the new technologies, percentage of contribution of the non-conventional energy sources in Vojvodina could be increased to as much as 20%. This paper presents the potential of development of bioethanol production in Vojvodina. Production of bioethanol on small farms can be successfully applied for processing of only 30kg of corn per day, with obtaining of crude ethanol in the so-called “brandy ladle” and use of lygnocellulosic agricultural wastes as an energy source. In a case of construction of a larger number of such plants, the only possible solution is seen in the principle of construction of the so-called “satellite plants”, which will on small farm produce crude ethanol, with obtaining and consumption of stillage for animal feeding, and consumption of agricultural wastes as energetic fuels. If stillage is to be used as feed in wet feeding, it is estimated that, because of restrictions established by the magnitude of animal farm, the upper limit of capacity of such enterprises that process is at some 10–15tons of corn per day, and production of 3000–3500hL of absolute ethanol per day. In such a case, for animal feeding necessary is to have herd with 1300–1700 of milking cows or 5000–25,000 heads of sheep and/or pigs. Technological model of separate grain processing ad bioethanol production from dextrose hydrolysates of starch is interesting for countries possessing plants for bioethanol production from molasses and plants for cereals processing into starch and dextrose hydrolysates of starch. [Copyright &y& Elsevier]