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The shift from straw incorporation to biofuel production entails emissions from production, changes in soil organic carbon (SOC) and through the provision of (co‐)products and entailed displacement effects. This paper analyses changes in greenhouse gas (GHG) emissions arising from the shift from straw incorporation to biomethane and bioethanol production. The biomethane concept comprises comminution, anaerobic digestion and amine washing. It additionally provides an organic fertilizer. Bioethanol production comprises energetic use of lignin, steam explosion, enzymatic hydrolysis and co‐fermentation. Additionally, feed is provided. A detailed consequential GHG balance with in‐depth focus on the time dependency of emissions is conducted: (a) the change in the atmospheric load of emissions arising from the change in the temporal occurrence of emissions comparing two steady states (before the shift and once a new steady state has established); and (b) the annual change in overall emissions over time starting from the shift are assessed. The shift from straw incorporation to biomethane production results in net changes in GHG emissions of (a) −979 (−436 to −1,654) and (b) −955 (−220 to −1,623) kg CO2‐eq. per tdry matter straw converted to biomethane (minimum and maximum). The shift to bioethanol production results in net changes of (a) −409 (−107 to −610) and (b) −361 (57 to −603) kg CO2‐eq. per tdry matter straw converted to bioethanol. If the atmospheric load of emissions arising from different timing of emissions is neglected in case (a), the change in GHG emissions differs by up to 54%. Case (b) reveals carbon payback times of 0 (0–49) and 19 (1–100) years in case of biomethane and bioethanol production, respectively. These results demonstrate that the detailed inclusion of temporal aspects into GHG balances is required to get a comprehensive understanding of changes in GHG emissions induced by the introduction of advanced biofuels from agricultural residues. [ABSTRACT FROM AUTHOR]

Bioethanol has been identified as a renewable product with high potential for application as biofuel. On the other hand, high volumes of agri‐food residues are generated daily. Such residues have potential as raw materials for industrial bioethanol production. There is a significant advance in the synthesis of biofuels from fruit and vegetable residues; however, most of the studies are focused on the conversion of a single type of raw material, limiting the application of the synthesis routes. This work presents a conversion methodology to produce bioethanol from carrot and broccoli residues and from their mixture; the samples of vegetable wastes has been collected in the municipality of Guanajuato, Mexico. Using the 1H NMR technique, the characteristic signals of bioethanol are identified. On the other hand, using the UV–VIS spectrophotometry technique, a maximum of 25.63 mg of total sugar content has been determined for the mixture. Likewise, a maximum bioethanol concentration of 60.6 g/L is obtained. From a refractometry and HPLC study, a conversion to bioethanol of 34.8% is determined for the mixture of residues. This work analyses the potential of broccoli and carrot residues for bioethanol production, either as isolated or as mixed wastes. [ABSTRACT FROM AUTHOR]

Microalgal biofuel is a promising solution to replace fossil fuel as a renewable and environmental‐friendly energy source, thereby contributing to the United Nations (UN) Sustainable Development Goals (SDGs), in particular SDG‐7, or Affordable and Clean Energy. Unlike energy crops (like oil palm and sugar cane), microalgae benefit from faster growth rate, higher lipid content, smaller land area required, ability to flourish using waste or brackish water, and posing zero competition with food crops. Microalgae‐derived biofuels (like biodiesel, bioethanol, biomethane, and biohydrogen) are sustainable energy sources that can be produced using well‐developed techniques (e.g., transesterification, fermentation, anaerobic digestion, and Fisher–Tropsch process). To prevent dire climate conditions resulting from the global temperature rise of 1.5°C and resolve worldwide energy security issue, our generation will need to establish and implement renewables on a global scale. To improve the industrial production of microalgal biofuel, the efficiencies of biomass and metabolite production to post‐cultivation biofuel synthesis processes must be enhanced. For the cultivation step, there exist three key techniques that can directly change the traits, structure, and behavior of microalgal cells, and induce them to accumulate targeted metabolites rapidly and in large amounts. These techniques are genetic engineering, chemical modulation, and nanomaterial approach. Genetic engineering commonly alters the chloroplast DNA of microalgae to overexpress or down‐regulate key genes in various metabolic pathways so that the cells accumulate more lipids. Chemicals can also be used to modulate microalgal growth and lipid accumulation by inducing oxidative stress or prevent conversion of lipid molecules. Nanomaterials and nanoparticles can also enhance microalgal lipid production by microenvironmental stress induction, vitamin supplementation, and light backscattering. Therefore, in this review, the recent progress as well as the pros and cons of genetic engineering, chemical modulation, and nanomaterial approach in achieving greater biofuel production from microalgae are comprehensively examined. [ABSTRACT FROM AUTHOR]

The energy supply characteristic of a proton-exchange membrane fuel cell for houses is strongly influenced in a hydrogen supply unit. Therefore, a bioethanol reforming system ( FBSR) with a sunlight heat source is developed as a potential fuel supply system for distributed fuel cells. However, the temperature distribution of a catalyst layer in the reactor is not stable under conditions of unstable solar radiation and unstable outside air temperature; as a result, it is thought that the inversion ratio (the percentage of hydrogen obtained from ethanol) of a reforming reaction will decrease. In this paper, heat transmission analysis was used in the catalyst layer of the reformer of FBSR, and the fundamental performance of FBSR was investigated. Fluctuations of the solar insolation over a short period of time affect the hydrogen-generating rate of FBSR. Moreover, the amount of hydrogen production of FBSR was simulated using meteorological data from a day in March and a day in August in a cold region (Sapporo in Japan). In this research, the relation between the collected area of a solar collector and the energy supply to an individual house was obtained. [ABSTRACT FROM AUTHOR]

The article discusses a study on the U.S. corn ethanol industry which was presented at an invited paper session at the 2013 annual meeting of the Allied Social Science Association in San Diego, California. It presents an analysis of the economic viability of corn ethanol production for use in the fuel market without subsidies in the 2014 when ethanol mandates take effect. It considers supply and demand for corn ethanol under certain price conditions such as that of corn and gasoline prices.

Abstract: Alkaline membrane fuel cells (AMFCs) have started to become more attractive in recent years due to the development of polymeric membranes with good anionic conductivity and durability. However, few studies investigating the performance of H2/O2 fueled AMFCs and alkaline direct ethanol fuel cells (DEFCs) with membrane electrode assemblies (MEAs) fabricated with Pt‐group metal (PGM)‐free catalysts are available in the literature. In this paper, we synthesized and fully characterized a Fe−Co−N−C electrocatalyst for the oxygen reduction reaction (ORR) by a sacrificial method, using pyrrole as a unique and inexpensive precursor for N‐doped carbonaceous materials. Very good ORR activity and stability were obtained in alkaline conditions, most likely due to the presence of Co−Fe@C nanoparticles. We achieved a very high performance in an AMFC, 420 mW cm−2 at 60 °C, among the highest in the literature for PGM‐free catalysts, and a good performance in a passive DEFC, 28 mW cm−2 at room temperature. [ABSTRACT FROM AUTHOR]

Bamboo has been identified as a promising solution to the energy crisis and climate change as a source of biomass energy. Due to its rapid growth and high‐value products, bamboo is considered as a potential source of biomass energy. Bamboo contains a significant amount of cellulose and hemicellulose, which can be converted to sugar constituents, making it an ideal raw material for energy production. This article reviews the different processes of producing bioethanol, biogas, biochar, and bio‐oil from bamboo biomass using techniques such as pyrolysis, hydrothermal liquefaction, fermentation, and anaerobic digestion, and discusses the opportunities and challenges of these conversion technologies. It also reviews the main types and morphological characteristics of energy bamboo species and proposes an evaluation system for energy bamboo species, which optimizes the utilization efficiency of bamboo biomass energy and maximizes benefits by adopting appropriate methods for producing bioenergy based on the characteristics of different bamboo species. [ABSTRACT FROM AUTHOR]

This paper explores the economic viability of producing biofuels from Agave in Mexico and the potential for it to complement the production of tequila or mescal. We focus on Agave varieties currently being used by the tequila industry to produce two beverages, tequila and mescal, and explore the potential for biofuel production from these plants. Without competing directly with beverage production, we discuss the economic costs and benefits of converting Agave by-products to liquid fuel as an additional value-added product and expanding cultivation of Agave on available land. We find that the feedstock cost for biofuel from the Agave piña alone could be more than US$3 L−1 on average. This is considerably higher than the feedstock costs of corn ethanol and sugarcane ethanol. However, there may be potential to reduce these costs with higher conversion efficiencies or by using sugar present in other parts of the plant. The costs of cellulosic biofuels using the biomass from the entire plant could be lower depending on the conversion efficiency of biomass to fuel and the additional costs of harvesting, collecting and transporting that biomass. [ABSTRACT FROM AUTHOR]

The article presents a study on the prices of corn crude oil combination and the factor to maintain a break even condition for ethanol producers. The study aims to conduct an economic impact analysis of alternative process for the promotion of ethanol production. It states that energy production is associated with agriculture, wherein the new market integration has been perceived to be an important factor in the field of agriculture. In addition, an integrated environment is essential in conducting a policy alternatives in market and designs.

Dates (Phoenix dactylifera L.) are rich in nutritional compounds, particularly in sugars. Sugars offer anaerobic fermentation, used for bioethanol production. Recently, researchers and industrialists finding ways to produce low‐cost bioethanol on large scale using agricultural wastes. Date palm residual is the largest agricultural waste in Pakistan, which can be the cheapest source for bioethanol production, whereas the current study was designed to explore the possible utilization and the potential of date palm waste for bioethanol production through Saccharomyces cerevisiae grown in yeast extract, Bacto peptone, and d‐glucose medium. The fermentation process resulted in the production of 15% (v/v) ethanol under the optimum condition of an incubation period of 72 hr and three sugars (glucose, fructose, and sucrose) were found in date waste. The functional group of ethanol (C2H5OH) was also found via Fourier‐transform infrared spectroscopy (FTIR) analysis. Therefore, S. cerevisiae could be recommended for ethanol production due to short fermentation time at 25% inoculum in 30°C and reduced the processing cost. Common date varieties of low market value are a preferred substrate for the process of producing industrial ethanol. Additionally, proximate analysis of date fruit by near‐infrared spectroscopy revealed moisture contents (16.84%), crude protein (0.3%), ash (9.8%), crude fat (2.6%), and neutral detergent fibers (13.4%). So, date fruit contains various nutrients for microbial growth for ethanol production. [ABSTRACT FROM AUTHOR]

One of the main goals of industrial biotechnology is to develop an effective method for ethanol production for fuel purposes using lignocellulosic biomass. Variability of lignocellulosic raw materials, selection of an effective method for the pretreatment of raw material, and selection of microorganisms with the ability to ferment not only hexoses but also pentoses and are moreover resistant to environmental stress generated by the products of lignocellulosic complex decomposition, are the challenges encountered in ethanol production. The use of agricultural wastelands and overgrowing plants that have little possibility of application in processes other than energy production seem to be an interesting alternative to conventional, but very often rather cultivation demanding energy crops. The aim of this study was to evaluate the possibility of using the stems of fireweed (Epilobium angustifolium L.), European goldenrod (Solidago virgaurea L.), and common broom (Cytisus scoparius L.) for ethanol production. The key elements studied were characteristics of the lignocellulosic complex structure, influence of the selected ionic liquids on the structural changes in biomass, and efficiency of enzymatic hydrolysis and ethanol fermentation processes. The results showed that under the assumed conditions the best effect was observed with the fireweed materials subjected to pretreatment with 1‐ethyl‐3‐methylimidazolium acetate and enzymatic hydrolysis with Viscozyme® preparation. The final concentration of ethanol obtained was 2.509 g L−1 with a yield of 92.3%. This was due to the highest share of cellulose (40.9%) in the whole lignocellulosic complex compared to other raw materials, which in combination with the selection of an appropriate ionic liquid and an enzymatic preparation, led to high bioprocess efficiency. [ABSTRACT FROM AUTHOR]

Bioenergy will play an intimate and critical role in energy supply and carbon mitigation in the future. In recent years, "customizing the development of bioenergy to local conditions" and "prioritizing distributed utilization" have been the two key principles that have been released by the Chinese government to promote the national‐ and provincial‐level development of bioenergy. While many recognize the importance of bioenergy in achieving low‐carbon transition, little is known about the high‐resolution distribution of usable biomass feedstock and technical bioenergy potential in China, which brings about uncertainties and additional challenges for creating localized utilization plans. We propose a new assessment framework that integrates crop growth models, a land suitability assessment, and the geographic information systems to address these knowledge gaps. Distributions of 11 types of usable biomass feedstock and three kinds of technical bioenergy potential are mapped out through specific transformation technologies at 1 km resolution. At the national level, the final technical biogas potential is 1.91 EJ. The technical bioethanol potential (0.04–0.96 EJ) from the energy crop can supply 0.13–3.12 times the bioethanol demand for the consumption of E10 gasoline in 2015. The technical heat potential (1.06 EJ) can meet 20% of the demand for heating in all provinces (5.38 EJ). Most of the 2020 bioenergy goals can be achieved, excluding that for bioethanol, which will need to require more cellulosic ethanol from residues. At the provincial level, Henan and Inner Mongolia have the potential to develop clean heating alternatives via the substitution of agroforestry residues for coal. The results can provide a systematic analysis of the distribution of biomass feedstocks and technical bioenergy potential in China. With economic factors taken into consideration in further research, it can also support national and provincial governments in making bioenergy development plans in an effective and timely manner. [ABSTRACT FROM AUTHOR]

Despite the recent discoveries of considerable fossil fuel reserves, Brazil is one of the only great economic and industrial powers with very high amounts of renewable energy in its electricity matrix. Approximately 79.3% of the electric energy supply comes from renewable resources, of which hydroelectric power represents 70.6%. The two primary concerns regarding hydroelectricity are the damage caused to the environment by the construction of dams and the uncertainty of the supply in cases of long drought seasons. This article presents an analysis on the availability and energy exploitation of sugarcane straw and forest residues derived from eucalyptus for decentralized generation using a Geographic Information System–based model. The potential bioelectricity and bioethanol production from sugarcane and eucalyptus biomass in the Administrative Region of Campinas (ARC) is higher than the demand in this region. The results provide guidelines for designing alternatives to the intended Nationally Determined Contributions in Brazil within the scope of the ARC, and they can be used to provide energy empowerment, electric matrix diversification, and new policies that address the residue availability and demand. [ABSTRACT FROM AUTHOR]

We show that the cost of increasing biofuel mandates given a binding ethanol blend wall falls disproportionately on diesel fuel consumers. The extent of the burden on diesel fuel consumers is explained neither by their relatively more inelastic demand nor by blenders seeking to capitalize on the biodiesel tax credit. Relaxing the blend wall constraint by increasing the potential demand for high-ethanol blends is the only effective lever to insulate diesel fuel drivers from the one-sided welfare impacts of rising mandate levels. The independent effects of the nested mandate structure and the joint compliance base under the Renewable Fuel Standard (RFS) generate the link between motor gasoline and diesel fuel markets. Our results highlight the importance of evaluating the incidence of the RFS in a holistic framework taking both ethanol and biodiesel into account. [ABSTRACT FROM AUTHOR]

Giant reed (Arundo donax L.) is a perennial rhizomatous grass, which has attracted great attention as a potential lignocellulosic feedstock for bioethanol production due to high biomass yield in marginal land areas, high polysaccharide content and low inhibitor levels in microbial fermentations. However, little is known about the trait variation that is available across a broad ecotypic panel of A. donax nor the traits that contribute most significantly to yield and growth in drought prone environments. A collection of 82 ecotypes of A. donax sampled across the Mediterranean basin was planted in a common garden experimental field in Savigliano, Italy. We analysed the collection using 367 clumps representing replicate plantings of 82 ecotypes for variation in 21 traits important for biomass accumulation and to identify the particular set of ecotypes with the most promising potential for biomass production. We measured morpho‐physiological, phenological and biomass traits and analysed causal relationships between traits and productivity characteristics assessed at leaf and canopy levels. The results identified differences among the 82 ecotypes for all studied traits: those showing the highest level of variability included stomatal resistance, stem density (StN), stem dry mass (StDM) and total biomass production (TotDM). Multiple regression analysis revealed that leaf area index, StDM, StN, number of nodes per stem, stem height and diameter were the most significant predictors of TotDM and the most important early selection criteria for bioenergy production from A. donax. These traits were used in a hierarchical cluster analysis to identify groups of similar ecotypes, and a selection was made of promising ecotypes for multiyear and multisite testing for biomass production. Heritability estimates were significant for all traits. The potential of this ecotype collection as a resource for studies of germplasm diversity and for the analysis of traits underpinning high productivity of A. donax is highlighted. A broad Euro‐Mediterranean panel of 82 ecotypes of giant reed (Arundo donax L.) were phenotyped in a common garden experimental field in Italy. Twenty one morpho‐physiological, phenological and biomass traits were measured and causal relationships were analysed between traits and productivity characteristics at leaf and canopy levels. Multiple regression analysis revealed that leaf area index, stem dry mass, stem density, number of nodes per stem, stem height, and diameter were the most significant predictors of total biomass production and the most important early selection criteria for bioenergy production from A. donax. [ABSTRACT FROM AUTHOR]

For second‐generation (2G) bioethanol refineries, the feedstock supply is one of the important parameters in terms of cost and consistency. Biorefineries are in most cases designed for a specific type of feedstock. For some biorefineries, the use of multiple feedstocks is an option, but how would such feedstocks perform when used in a process designed and optimized for a specific feedstock? There is no "one‐size‐fits‐all" processing package, due to variations in composition and structure of different feedstock types, but due to the size of commercial biorefineries, only minor adjustments of the processing parameters are practically feasible. In this study, 16 alternative feedstocks were characterized and compared to the benchmark feedstock wheat straw under identical processing conditions. The alternative feedstocks studied were as follows: barley straw, rye straw, grass straw, oat straw, Norway spruce sawdust, mixed softwood sawdust, oat wrap, biogas fiber, deep litter, washed deep litter, ryegrass fiber, lucerne fiber, ryegrass chaff, mixed grain chaff, rapeseed press cake, and beer production mash. These biomasses varied in carbohydrate content and accessibility after hydrothermal pretreatment. Applying a hydrothermal pretreatment under identical conditions, the subsequent enzymatic convertibility of these biomasses ranged from 0.5% to complete conversion based on their glucan content. Water retention value was determined and correlated with enzymatic convertibility, which provided a simple method for indirect measurement of biomass recalcitrance. Ethanol potentials were estimated based on carbohydrate release from enzymatic hydrolysis, and yeast toxicity test was performed on liquid fractions from hydrothermal pretreatment. Furthermore, a number of key processing indicators, including market price, logistics and availability, were taken into consideration based on a proposed full‐scale 2G ethanol plant in Denmark. The overall results show that while some feedstocks had inferior performance compared to wheat straw, identical or even superior performance was observed from barley, oat, and ryegrass feedstocks. In northern Europe, wheat straw is the most important feedstock, which defines the processing parameters in 2G biorefineries, and the compatibility of other common 2G feedstocks to these parameters is investigated in this study. The alternative feedstocks studied were as follows: barley straw, rye straw, grass straw, oat straw, Norway spruce sawdust, mixed softwood sawdust, oat wrap, biogas fiber, deep litter, washed deep litter, ryegrass fiber, lucerne fiber, ryegrass chaff, mixed grain chaff, rape seed press cake, and beer production mash. These biomasses varied in carbohydrate content, carbohydrate accessibility, enzymatic hydrolysis yield, and ethanol potential, after hydrothermal pretreatment. [ABSTRACT FROM AUTHOR]

Due to its fast‐growing and high carbohydrate content, Napier grass has a great potential to be chosen as a raw material for renewable energy production. The Napier grass after different pretreatments was tested for simultaneous saccharification and fermentation (SSF) with dried yeast (Saccharomyces cerevisiae) and cellulase (CTec2) to produce ethanol. For alkaline pretreatment, the grass was incubated with 10% NaOH at a ratio of 1:20 (w/v) at 90°C for 1 hour. For dilute acid pretreatment, the grass was soaked with 1% H2SO4 at a ratio of 1:10 (w/v) and incubated at 120°C for 1 hour. For the two‐stage pretreatment, the resultant solid from dilute acid pretreatment was further treated with 2% NaOH (1:10 w/v) at 80°C for 6 hours. After enzymatic saccharification at 50°C and pH 5.0 for 96 hours using CTec2, yields of glucose from three pretreated Napier grass samples (10% water‐insoluble solids, WIS) were 75.4 ± 2.9%, 55.4 ± 6.5%, and 76.4 ± 5.0%. Using 10% WIS of alkaline‐pretreated Napier grass biomass as the substrate, the 72‐hour SSF led to an ethanol yield of 86.6 ± 3.4%. On the basis of the dried biomass of Napier grass as the raw material, the ethanol yield could reach 0.143 ± 0.006 (g/g). Napier grass biomass could be effectively treated by alkaline, dilute acid, or two‐stage pretreatment methods to remove non‐cellulosic components to some extent. Alkaline pretreatment was found to be superior to dilute acid and two‐stage pretreatment methods, based on ethanol yields obtained under similar SSF conditions. Napier grass was pretreated by alkaline, dilute acid, and two‐stage methods. Highest ethanol yield was obtained from alkaline pretreated Napier grass. An ethanol yield of 0.143 g/g‐dried raw material of Napier grass was achieved by simultaneous saccharification and fermentation (SSF). [ABSTRACT FROM AUTHOR]

Many of the sustainability concerns of bioenergy are related to direct or indirect land use change (LUC) resulting from bioenergy feedstock production. The environmental and socio‐economic impacts of LUC highly depend on the site‐specific biophysical and socio‐economic conditions. The objective of this study is to spatiotemporally assess the potential LUC dynamics resulting from an increased biofuel demand, the related greenhouse gas (GHG) emissions, and the potential effect of LUC mitigation measures. This assessment is demonstrated for LUC dynamics in Brazil towards 2030, considering an increase in the global demand for bioethanol as well as other agricultural commodities. The potential effects of three LUC mitigation measures (increased agricultural productivity, shift to second‐generation ethanol, and strict conservation policies) are evaluated by using a scenario approach. The novel modelling framework developed consists of the global Computable General Equilibrium model MAGNET, the spatiotemporal land use allocation model PLUC, and a GIS‐based carbon module. The modelling simulations illustrate where LUC as a result of an increased global ethanol demand (+26 × 109 L ethanol production in Brazil) is likely to occur. When no measures are taken, sugar cane production is projected to expand mostly at the expense of agricultural land which subsequently leads to the loss of natural vegetation (natural forest and grass and shrubland) in the Cerrado and Amazon. The related losses of above and below ground biomass and soil organic carbon result in the average emission of 26 g CO2‐eq/MJ bioethanol. All LUC mitigation measures show potential to reduce the loss of natural vegetation (18%–96%) as well as the LUC‐related GHG emissions (7%–60%). Although there are several uncertainties regarding the exact location and magnitude of LUC and related GHG emissions, this study shows that the implementation of LUC mitigation measures could have a substantial contribution to the reduction of LUC‐related emissions of bioethanol. However, an integrated approach targeting all land uses is required to obtain substantial and sustained LUC‐related GHG emission reductions in general. The additional demand of bioethanol (+26 billion liters in 2030) results in land use changes and related GHG emissions in Brazil. Sugar cane expansion is projected to occur mainly in the central south with in turn leads to losses of natural vegetation in the Cerrado and the Amazon. Land use change mitigation measures can significantly reduce the loss of natural land (forest and grass and shrubland) and land use change‐related greenhouse gas emissions resulting from bioethanol production. [ABSTRACT FROM AUTHOR]

Abstract: The growing interest in biofuel as a green energy source has intensified the linkages between corn and ethanol markets, especially in the United States that represents the largest producing and exporting country for ethanol in the world. In this study, we examine the effect of corn market uncertainty on the price changes of US ethanol applying a set of GARCH‐jump models. We find that the US ethanol price changes react positively to the corn market volatility shocks after controlling for the effect of oil price uncertainty. In addition, we document that the impact of corn price volatility on the US ethanol prices appears to be asymmetric. Specifically, only the positive corn market volatility shocks are found to influence the ethanol market returns. Our findings also suggest that time‐varying jumps do exist in the ethanol market. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study was to investigate the causal relationships among crude oil, ethanol and sugar prices in the context of Brazil. In doing so, we consider the application of ARDL bound tests to examine whether these variables comove in the long run. Besides, we employ a recently developed nonlinear symmetric and asymmetric test for noncausality which assists us to explore the short‐run ‘lead–lag’ associations among the price indexes under review. The results of the ARDL bound test indicate that cointegration exists only when the ethanol price is used as the dependent variable. This finding suggests that oil and sugar prices lead the Brazilian ethanol prices in the long run. Moreover, the results of nonlinear causality test also confirm the existence of a short‐term unidirectional causality running from sugar to ethanol market. We also document that the impact of sugar prices on ethanol prices appears to be positive indicating that rising sugar prices will cause a growth in the ethanol prices. Our findings further demonstrate that sugar prices are not affected by the fluctuations in ethanol price. The results carry important implications for policymakers. [ABSTRACT FROM AUTHOR]

Summary: Sugarcane is the world's most efficient feedstock for commercial production of bioethanol due to its superior biomass production and accumulation of sucrose in stems. Integrating first‐ and second‐generation ethanol conversion processes will enhance the biofuel yield per unit area by utilizing both sucrose and cell wall‐bound sugars for fermentation. RNAi suppression of the lignin biosynthetic gene caffeic acid O‐methyltransferase (COMT) has been demonstrated to improve bioethanol production from lignocellulosic biomass. Genome editing has been used in a number of crops for creation of loss of function phenotypes but is very challenging in sugarcane due to its highly polyploid genome. In this study, a conserved region of COMT was targeted with a single‐transcription activator‐like effector nuclease (TALEN) pair for multi‐allelic mutagenesis to modify lignin biosynthesis in sugarcane. Field‐grown TALEN‐mediated COMT mutants showed up to 19.7% lignin reduction and significantly decreased syringyl to guaiacyl (S/G) ratio resulting in an up to 43.8% improved saccharification efficiency. Biomass production of COMT mutant lines with superior saccharification efficiency did not differ significantly from the original cultivar under replicated field conditions. Sanger sequencing of cloned COMT amplicons (1351–1657 bp) revealed co‐editing of 107 of the 109 unique COMT copies/alleles in vegetative progeny of line CB6 using a single TALEN pair. Line CB6 combined altered cell wall composition and drastically improved saccharification efficiency with good agronomic performance. These findings confirm the feasibility of co‐mutagenesis of a very large number of target alleles/copies for improvement in crops with complex genomes. [ABSTRACT FROM AUTHOR]

One of the obstacles constraining bio‐ethanol production using cellulose is enzymatic hydrolysis. Uniform distribution of slurry residence time is important to improve the efficiency. Efforts were made to develop a novel quasi plug‐flow reactor on industrial scale for enzymatic hydrolysis of cellulose by CFD simulation. Ahead of numerical simulation, the rheological properties of the cellulose enzymolysis slurry of furfural residues were studied based on experiments. A turbulence model called k‐kl‐ω was employed in CFD simulation, which was good at describing the flow field with great variation on the extent of turbulence in the stirred tank. Vertical blades, pitched blades, helical ribbons, and their combination were investigated firstly, and then the internal structures were optimized. The calculated residence time distribution curve showed that the quasi plug‐flow reactor had the following features: (1) combination of double helical ribbons and vertical blade, (2) two partitions and four baffles, (3) flow area was 0.1 m2 on partitions. The CFD simulation methods and results could provide a theoretical guidance for the development of a novel quasi plug‐flow reactor to improve the efficiency of the cellulose enzymatic hydrolysis on industrial scale. [ABSTRACT FROM AUTHOR]

Concerns over energy shortages and global climate change have stimulated developments toward renewable energy. Biofuels have been developed to replace fossil fuels to reduce the emissions of greenhouse gases and other environmental impacts. However, food security and water scarcity are other growing concerns, and the increased production of biofuels may increase these problems. This study focuses on whether biofuel development would stress China's water resources. Cassava-based fuel ethanol and sweet sorghum-based fuel ethanol are the focus of this study because they are the most typical nongrain biofuels in China. The spatial distribution of the total water requirement of fuel ethanol over its life cycle process was simulated using a biophysical biogeochemical model and marginal land as one of the types of input data for the model to avoid impacts on food security. The total water requirement of fuel ethanol was then compared with the spatial distribution of water resources, and the influence of the development of fuel ethanol on water resources at the pixel and river basin region scales was analyzed. The result showed that the total water requirement of fuel ethanol ranges from 37.81 to 862.29 mm. However, considering water resource restrictions, not all of the marginal land is suitable for the development of fuel ethanol. Approximately 0.664 million km2 of marginal land is suitable for the development of fuel ethanol, most of which is located in the south of China, where water resources are plentiful. For these areas, the value of fuel ethanol's water footprint ranges from 0.05 to 11.90 m3 MJ−1. From the water point of view, Liaoning province, Guizhou province, Anhui province and Hunan province can be given priority for the development of fuel ethanol. [ABSTRACT FROM AUTHOR]

ABSTRACT This study used a stated choice experimental survey to evaluate the effects of contract design mechanisms and farmers' risk preferences in supplying biomass for ethanol production in a vertically coordinated biomass supply chain in Northern Plain of the United States. A rank-ordered logit model was used to assess the effects of price- and quantity-based contract mechanisms, risk preferences, and farm characteristics on ranking of contract preferences. Our empirical results show that, under price-based contract, farmers are likely to prefer contract that set fixed price when a contract was offered over short term, however, over the long term, farmers prefer a contract item that set formula with a floor price. Under quantity-based design mechanism, our model results illustrate that contract items that limit biomass quantity delivery requirement become less preferable even if farmers are allowed to negotiate on delivery price. In addition, farmer's risk perception factors toward engaging in marketing organization and vertically coordinated supply chains play a significant role in ranking contract preferences. [EconLit citations: D82; Q13; Q42] [ABSTRACT FROM AUTHOR]

ABSTRACT This study compares price transmission behaviors between pre- and post-EPA (Energy Policy Act) periods to investigate the impact of increased production of corn ethanol on price transmission behaviors between five regional fed cattle markets in the United States: Colorado, Iowa-Minnesota, Kansas, Nebraska, and Texas-Oklahoma. Econometric models used in this study consider potential nonlinearity and asymmetry in price transmissions using threshold autoregression and threshold error correction methods, and generalized impulse response functions. Overall, the surge of corn ethanol production after the EPA enactment appears to lead lower integration and slower price adjustment between markets, particularly between noncorn-belt and corn-belt markets. Our analysis also finds strong evidence of the existence of threshold effects and limited evidence of asymmetric price responses in the short and long run for both pre- and post-EPA periods. [EconLit citations: C32, Q13]. [ABSTRACT FROM AUTHOR]

In this work, the well-defined Pt hollow nanospheres with the rough porous surface are synthesized by a facile self-templated approach. The formation of the spherical Pt(II)-urea complex plays a key role in the generation of Pt hollow nanospheres. Sodium formate is employed as the suitable reducing agent for reducing Pt(II)-urea complexes. The hollow structure and the rough porous surface with abundant atomic defects are confirmed by scanning electron microscopy and transmission electron microscopy, respectively. The CO-stripping experiment reveals that these abundant atomic defects effectually enhance the electrocatalytic activity of the Pt hollow nanospheres for the CO oxidation reaction. Moreover, the low activation energy of the ethanol oxidation reaction (EOR) on the Pt hollow nanospheres indicates that the hollow structure and the rough porous surface are beneficial kinetically for the EOR in alkaline media. Compared with commercial Pt black, the as-prepared Pt hollow nanospheres show the enhanced electrocatalytic activity and stability for the EOR in alkaline media. In view of the enhanced catalytic activity and the facile self-templated approach, the Pt hollow nanospheres may be a new promising electrocatalyst for alkaline direct ethanol fuel cells. [ABSTRACT FROM AUTHOR]

Increasing production of biofuels has led to concerns about indirect land-use change ( ILUC). So far, significant efforts have been made to assess potential ILUC effects. But limited attention has been paid to strategies for reducing the extent of ILUC and controlling the type of LUC. This case study assesses five key ILUC mitigation measures to quantify the low- ILUC-risk production potential of miscanthus-based bioethanol in Lublin province (Poland) in 2020. In 2020, a total area of 196 to 818 thousand hectare of agricultural land could be made available for biomass production by realizing above-baseline yield developments (95-413 thousand ha), increased food chain efficiencies (9-30 thousand ha) and biofuel feedstock production on underutilized lands (92-375 thousand ha). However, a maximum 203-269 thousand hectare is considered legally available (not protected) and biophysically suitable for miscanthus production. The resulting low- ILUC-risk bioethanol production potential ranges from 12 to 35 PJ per year. The potential from this region alone is higher than the national Polish target for second-generation bioethanol consumption of 9 PJ in 2020. Although the sustainable implementation potential may be lower, the province of Lublin could play a key role in achieving this target. This study shows that the mitigation or prevention of ILUC from bioenergy is only possible when an integrated perspective is adopted on the agricultural and bioenergy sectors. Governance and policies on planning and implementing ILUC mitigation are considered vital for realizing a significant bioenergy potential with low ILUC risk. One important aspect in this regard is monitoring the risk of ILUC and the implementation of ILUC mitigation measures. Key parameters for monitoring are land use, land cover and crop yields. [ABSTRACT FROM AUTHOR]

One approach for handling more aggressive goals under an ethanol mandate is to use a 'dual blend' mandate in which both the preferred new ethanol blend and the old (possibly ethanol-free) blend of gasoline coexist. Highlighting the case of New South Wales, Australia, we show the dual nature of such a mandate can potentially lead to significant costs when consumers are averse. We show consumers en masse rejected the new blend and paid 43 cents per gallon more to avoid it. Not even the second of the mandate's four targets could be reached, and the consumer cost was substantial. ( JEL L51, Q41, Q42, Q51) [ABSTRACT FROM AUTHOR]

Currently, biomass contributes to ∼14 % of global energy needs. Therefore, many studies and policies have been developed in order to expand the participation of renewable energy in the global energy matrix. In this context, ethanol has received substantial interest. This work investigates ways to improve efficiency in ethanol production from sweet potatoes, considering the costs that make the process potentially implementable. The following aspects were investigated: (i) conversion efficiency according to the post-harvest time; (ii) influence of the heating method (water bath (conventional) and microwave) as well as the corresponding processing costs. The conversion efficiency increased significantly during sweet potato ripening, where the highest value was achieved 25 days after harvest. This is a very important result since it has a strong impact on the final cost. Among the heating methods, the conventional one was slightly superior in terms of conversion efficiency (9 % higher at 25 days) and also had better results regarding cost analysis. Among four designed scenarios, the largest cost difference was 17.5 %. Instead of a definitive elimination of microwave heating, the results should be analyzed to identify where the microwave heating should be improved in order to make it more attractive in the future. [ABSTRACT FROM AUTHOR]

Increased biomass yield and quality are of great importance for the improvement of feedstock for the biorefinery. For the production of bioethanol, both stem biomass yield and the conversion efficiency of the polysaccharides in the cell wall to fermentable sugars are of relevance. Increasing the endogenous levels of gibberellic acid ( GA) by ectopic expression of GA20- OXIDASE1 ( GA20- OX1), the rate-limiting step in GA biosynthesis, is known to affect cell division and cell expansion, resulting in larger plants and organs in several plant species. In this study, we examined biomass yield and quality traits of maize plants overexpressing GA20- OX1 ( GA20- OX1). GA20- OX1 plants accumulated more vegetative biomass than control plants in greenhouse experiments, but not consistently over two years of field trials. The stems of these plants were longer but also more slender. Investigation of GA20- OX1 biomass quality using biochemical analyses showed the presence of more cellulose, lignin and cell wall residue. Cell wall analysis as well as expression analysis of lignin biosynthetic genes in developing stems revealed that cellulose and lignin were deposited earlier in development. Pretreatment of GA20- OX1 biomass with Na OH resulted in a higher saccharification efficiency per unit of dry weight, in agreement with the higher cellulose content. On the other hand, the cellulose-to-glucose conversion was slower upon HCl or hot-water pretreatment, presumably due to the higher lignin content. This study showed that biomass yield and quality traits can be interconnected, which is important for the development of future breeding strategies to improve lignocellulosic feedstock for bioethanol production. [ABSTRACT FROM AUTHOR]

Lignocellulosic feedstock has tremendous potential to sustain the renewable production of biofuels such as ethanol and butanol. Although lignocellulosic biomass is a storehouse of energy in the form of cellulose and hemicellulose, yet lignin acts as a barrier against their hydrolysis. A dilute acid pretreatment disintegrates the biomass complex and allows cellulolytic enzymes to hydrolyze cellulose and hemicelluloses in releasing fermentable sugars. The current study investigates the effect of different H2SO4 doses (0-2.5%) on the three lignocellulosic feedstock material, especially pinewood, timothy grass, and wheat straw at 121°C for 1 h. Furthermore, the pretreated feedstock was subjected to enzymatic hydrolysis using cellulase, β-glucosidase, and xylanase at 45°C for 72 h. The biomass hydrolysates containing monomeric sugars (glucose and xylose) were fermented using Saccharomyces cerevisiae and Clostridium beijerinckii for ethanol and butanol production, respectively. A comparative evaluation for the concentrations of ethanol and butanol, residual sugars as well as byproducts such as acetone, acetate, and butyrate from biomass hydrolysates was performed. Pinewood hydrolysate revealed high ethanol (24.1 g/L) and butanol (11.6 g/L) concentrations due to greater sugar content. In contrast to ethanol fermentation by S. cerevisiae, butanol fermentation by C. beijerinckii demonstrated low butanol levels in the hydrolysates due to butanol toxicity toward clostridia. [ABSTRACT FROM AUTHOR]

The rising volume of bioethanol production is likely to saturate the market for the current coproduct, distiller's dried grains with solubles (DDGS) as its high fiber content limits its use in nonruminant feed. A novel process has been developed which separates out a protein-rich yeast fraction from the ethanol stillage which may be more suitable as a feed ingredient for nonruminants than DDGS. The aim of this study was to characterize a high protein coproduct stream from wheat bioethanol production and to examine its efficacy as a protein source in meat poultry diets. The novel material was evaluated by examining effects of dietary inclusion on both pellet quality and key nutrient parameters for broiler chickens including feed conversion efficiency, mineral availability, and digestible amino acid content. Results showed that the yeast protein concentrate appears to be a viable feed material with the potential to partially replace soya in poultry feed and could be produced in large volumes. This scale of production of sustainable protein could alleviate some of the pressures on other protein sources and mitigate the high proportion of cereal consumed through bioethanol production. [ABSTRACT FROM AUTHOR]

The article reports that inorder to fulfill the need of biofuel, India has announced targets for blending ethanol with gasoline in 2017. It analyzes the capacity of the country to increase its production of ethenol and the cost-effective mix of feedstocks to meet the 20 percent blend mandate in 2017 and its implications for food prices in India.

Transport accounts for about one quarter of South Africa's final energy consumption. Most of the energy used is based on fossil fuels causing significant environmental burdens. This threat becomes even more dominant as a significant growth in transport demand is forecasted, especially in South Africa's economic hub, Gauteng province. The South African government has realized the potential of biofuel usage for reducing oil import dependency and greenhouse gas ( GHG) and has hence developed a National Biofuels Industrial Strategy to enforce their use. However, there is limited experience in the country in commercial biofuel production and some of the proposed crops (i.e. rapeseed and sugar beet) have not been yet cultivated on a larger scale. Furthermore, there is only limited research available, looking at the feasibility of commercial scale biofuel production or abatement costs of GHG emissions. To assess the opportunities of biofuel production in South Africa, the production costs and consumer price levels of the fuels recommended by the national strategy are analysed in this article. Moreover, the lifecycle GHG emissions and mitigation costs are calculated compared to the calculated fossil fuel reference including coal to liquid ( CTL) and gas to liquid ( GTL) fuels. The results show that the cost for biofuel production in South Africa are currently significantly higher (between 30% and 80%) than for the reference fossil fuels. The lifecycle GHG emissions of biofuels (especially for sugar cane) are considerably lower (up to 45%) than the reference fossil GHG emissions. The resulting GHG abatement costs are between 1000 and 2500 ZAR2007 per saved ton of carbon dioxide equivalent, which is high compared to the current European CO2 market prices of ca. 143 ZAR2007 t−1. The analysis has shown that biofuel production and utilization in South Africa offers a significant GHG-mitigation potential but at relatively high cost. [ABSTRACT FROM AUTHOR]

One way of reducing the emissions of fossil fuel-derived carbon dioxide ( CO2) is to replace fossil fuels with biofuels produced from agricultural biomasses or residuals. However, cultivation of soils results in emission of other greenhouse gases ( GHGs), especially nitrous oxide ( N2O). Previous studies on biofuel production systems showed that emissions of N2O may counterbalance a substantial part of the global warming reduction, which is achieved by fossil fuel displacement. In this study, we related measured field emissions of N2O to the reduction in fossil fuel-derived CO2, which was obtained when agricultural biomasses were used for biofuel production. The analysis included five organically managed feedstocks (viz. dried straw of sole cropped rye, sole cropped vetch and intercropped rye-vetch, as well as fresh grass-clover and whole crop maize) and three scenarios for conversion of biomass into biofuel. The scenarios were (i) bioethanol, (ii) biogas and (iii) coproduction of bioethanol and biogas. In the last scenario, the biomass was first used for bioethanol fermentation and subsequently the effluent from this process was utilized for biogas production. The net GHG reduction was calculated as the avoided fossil fuel-derived CO2, where the N2O emission was subtracted. This value did not account for fossil fuel-derived CO2 emissions from farm machinery and during conversion processes that turn biomass into biofuel. The greatest net GHG reduction, corresponding to 700-800 g CO2 m−2, was obtained by biogas production or coproduction of bioethanol and biogas on either fresh grass-clover or whole crop maize. In contrast, biofuel production based on lignocellulosic crop residues (i.e. rye and vetch straw) provided considerably lower net GHG reductions (≤215 g CO2 m−2), and even negative numbers sometimes. No GHG benefit was achieved by fertilizing the maize crop because the extra crop yield, and thereby increased biofuel production, was offset by enhanced N2O emissions. [ABSTRACT FROM AUTHOR]

The new renewable fuels standard ( RFS 2) aims to distinguish corn-ethanol that achieves a 20% reduction in greenhouse gas ( GHG) emissions compared with gasoline. Field data from Kim et al. (2009) and from our own study suggest that geographic variability in the GHG emissions arising from corn production casts considerable doubt on the approach used in the RFS 2 to measure compliance with the 20% target. If regulators wish to require compliance of fuels with specific GHG emission reduction thresholds, then data from growing biomass should be disaggregated to a level that captures the level of variability in grain corn production and the application of life cycle assessment to biofuels should be modified to capture this variability. [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]

This article reviews the history and current state of ethanol production from sugarcane in Brazil and presents a strategy for improving ecosystem services and production. We propose that it is possible to produce ethanol from sugarcane while maintaining or even recovering some of Brazil's unique neotropical biodiversity and ecosystem climate services. This approach to the future of sustainable and responsible ethanol production is termed the 'midway' strategy. The 'midway' strategy involves producing the necessary biotechnology to increase productivity while synergistically protecting and regenerating rainforest. Three main areas of scientific and technological advance that are key to realizing the 'midway' strategy are: (i) improving the quality of scientific data on sugarcane biology as pertains to its use as a bioenergy crop; (ii) developing technologies for the use of bagasse for cellulosic ethanol; and (iii) developing policies to improve the ecosystem services associated with sugarcane landscapes. This article discusses these three issues in the general context of biofuels production and highlights examples of scientific achievements that are already leading towards the 'midway' strategy. [ABSTRACT FROM AUTHOR]

Biofuel initiatives in India have gained momentum with the national biofuel policy targeting 20% blending of both petrol and diesel by 2017. Most of India's biofuel plans revolve around using sugarcane for bioethanol and jatropha for biodiesel production. This study, taking the southern Indian state of Karnataka as an example, aims at estimating the potential to achieve policy targets. The study spatially analyses land-use change owing to biofuel expansion and its effects on food production. We used an integrated modelling framework to simulate land-use change and bioenergy production under two scenarios - Industrial Economy ( IE) and Agricultural Economy ( AE). Results indicate that meeting the 20% blending target is a challenging goal to achieve under both scenarios. Bioethanol requirements can be nearly fulfilled (88% under IE and 93% under AE) because of sugarcane expansion. However, biodiesel demands cannot be fulfilled using only degraded lands as currently planned in India, but additional agricultural land (3-4% of the total cropland) will be required for jatropha-based biodiesel production. Food production will not be directly impacted until 2025, because the largest source of additional land could be short- and long-term fallows. We conclude that conservation oriented initiatives, such as water harvesting and energy conservation measures can increase productivities of biofuel crops and reduce fuel demands, respectively. State support and Clean Development Mechanism opportunities can enhance economic incentives for energy cropping. Therefore, a simultaneous and multipronged approach is needed to accommodate food and fuel demands in India. [ABSTRACT FROM AUTHOR]

We present an approach for providing quantitative insight into the production-ecological sustainability of biofuel feedstock production systems. The approach is based on a simple crop-soil model and was used for assessing feedstock from current and improved production systems of cassava for bioethanol. Assessments were performed for a study area in Mozambique, a country considered promising for biomass production. Our focus is on the potential role of smallholders in the production of feedstock for biofuels. We take cassava as the crop for this purpose and compare it with feedstock production on plantations using sugarcane, sweet sorghum and cassava as benchmarks. Production-ecological sustainability was defined by seven indicators related to resource-use efficiency, soil quality, net energy production and greenhouse gas (GHG) emissions. Results indicate that of the assessed systems, sugarcane performed better than cassava, although it requires substantial water for irrigation. Targeted use of nutrient inputs improved sustainability of smallholder cassava. Cassava production systems on more fertile soils were more sustainable than those on less fertile soils; the latter required more external inputs for achieving the same output, affecting most indicators negatively and reducing the feasibility for smallholders. Cassava and sweet sorghum performed similarly. Cassava production requires much more labour per hectare than production of sugarcane or sweet sorghum. Production of bioethanol feedstock on cultivated lands was more sustainable and had potential for carbon sequestration, avoiding GHG emissions from clearing natural vegetation if new land is opened. [ABSTRACT FROM AUTHOR]

An open-economy equilibrium model is derived to investigate the effects of energy policy on the U.S. economy, with emphasis on corn-based ethanol. A second best policy of a fuel tax and ethanol subsidy is found to approximate fairly closely the welfare gains associated with the first best policy of an optimal carbon tax and tariffs on traded goods. The largest economic gains to the U.S. economy from these energy policies arise from their impact on U.S. terms of trade, particularly in the oil market. Conditional on the current fuel tax, an optimal ethanol mandate is superior to an optimal ethanol subsidy. [ABSTRACT FROM PUBLISHER]

Bioethanol production from sugarcane is discussed as an alternative energy source to reduce dependencies of regional economies on fossil fuels. Even though bioethanol production from sugarcane is considered to be a beneficial and cost-effective greenhouse gas (GHG) mitigation strategy, it is still a matter of controversy due to insufficient information on the total GHG balance of this system. Aside from the necessity to account for the impact of land use change (LUC), soil N2O emissions during sugarcane production and emissions of GHG due to preharvest burning may significantly impact the GHG balance. Based on a thorough literature review, we show that direct N2O emissions from sugarcane fields due to nitrogen (N) fertilization result in an emission factor of 3.87±1.16% which is much higher than suggested by IPCC (1%). N2O emissions from N fertilization accounted for 40% of the total GHG emissions from ethanol-sugarcane production, with an additional 17% from trash burning. If LUC-related GHG emissions are considered, the total GHG balance turns negative mainly due to vegetation carbon losses. Our study also shows that major gaps in knowledge still exist about GHG sources related to agricultural management during sugarcane production, e.g. effects of irrigation, vinasse and filter cake application. Therefore, more studies are needed to assess if bioethanol from sugarcane is a viable option to reduce energy-related GHG emissions. [ABSTRACT FROM AUTHOR]

Peng Zhang
(Corresponding author) As a major source of food, cassava (Manihot esculenta Crantz) is an important root crop in the tropics and subtropics of Africa and Latin America, and serves as raw material for the production of starches and bioethanol in tropical Asia. Cassava improvement through genetic engineering not only overcomes the high heterozygosity and serious trait separation that occurs in its traditional breeding, but also quickly achieves improved target traits. Since the first report on genetic transformation in cassava in 1996, the technology has gradually matured over almost 15 years of development and has overcome cassava genotype constraints, changing from mode cultivars to farmer‐preferred ones. Significant progress has been made in terms of an increased resistance to pests and diseases, biofortification, and improved starch quality, building on the fundamental knowledge and technologies related to planting, nutrition, and the processing of this important food crop that has often been neglected. Therefore, cassava has great potential in food security and bioenergy development worldwide. [ABSTRACT FROM AUTHOR]

The overall goal of this work was to develop a saccharification method for the production of third generation biofuel (i.e. bioethanol) using feedstock of the invasive marine macroalga Gracilaria salicornia. Under optimum conditions (120 °C and 2% sulfuric acid for 30 min), dilute acid hydrolysis of the homogenized invasive plants yielded a low concentration of glucose (4.1 mM or 4.3 g glucose/kg fresh algal biomass). However, two‐stage hydrolysis of the homogenates (combination of dilute acid hydrolysis with enzymatic hydrolysis) produced 13.8 g of glucose from one kilogram of fresh algal feedstock. Batch fermentation analysis produced 79.1 g EtOH from one kilogram of dried invasive algal feedstock using the ethanologenic strain Escherichia coli KO11. Furthermore, ethanol production kinetics indicated that the invasive algal feedstock contained different types of sugar, including C5‐sugar. This study represents the first report on third generation biofuel production from invasive macroalgae, suggesting that there is great potential for the production of renewable energy using marine invasive biomass. [ABSTRACT FROM AUTHOR]

The article presents an analysis on the alternative pathways to achieve the renewable fuel standard (RFS) targets. It states that Excel spreadsheet model was used to analyze the impacts of various alternative RFS pathways including blend limit that remains at 10%, blend limit is increased to 15%, and blend limit is 10%. The analysis reveals that ethanol cannot be the sole biofuel in the U.S. market and that blend wall turn out to be an impenetrable barrier to achieve RFS.

An integrated, socioeconomic-biogeophysical model is used to analyze the interactions of cap-and-trade legislation and the Renewable Fuels Standard. Five alternative policy scenarios were considered with the purpose of identifying policies that act in a synergistic manner to reduce carbon emissions, increase economic returns to agriculture, and adequately meet ethanol mandates. We conclude that climate and energy policies can best be implemented together by offering carbon offset payments to conservation tillage, herbaceous grasses for biomass, and by constraining crop residue removal for ethanol feedstocks to carbon neutral level. When comparing this scenario to the Baseline scenario, the agricultural sector realizes an economic benefit of US$156 billion by 2030 and emissions are reduced by 135 Tg C-equivalent (Eq) yr−1. Results also indicate that geographic location of cellulosic feedstocks could shift significantly depending on the final policies implemented in cap and trade legislation. Placement of cellulosic ethanol facilities should consider these possible shifts when determining site location. [ABSTRACT FROM AUTHOR]

A study was conducted to examine the chemical composition of corn oil obtained after fermentation of corn to make fuel ethanol via centrifugation and compare its composition to that of corn germ oil (commercial corn oil) and experimental corn oils. The levels of free fatty acids in the post fermentation corn oil were high (11–16%), as previously reported. The levels of free phytosterols and hydroxycinnamate steryl esters (similar to oryzanol in rice bran oil) were higher than those of corn germ oil and were comparable to those of ethanol-extracted corn kernel oil. The levels of tocopherols were lower in post-fermentation oil than in either corn germ oil or ethanol extracted corn kernel oil. The levels of lutein and zeaxanthin in post-fermentation were much higher than those in corn germ oil and were comparable to those in ethanol-extracted corn kernel oil. Overall, exposure to all upstream processes of a fuel ethanol plant, including high-temperature liquefaction, saccharification and fermentation appeared to have the most notable effect on tocopherols, but it had little effect on the levels of free phytosterols, hydroxycinnamate steryl esters, lutein and zeaxanthin. It may be desirable to recover these valuable functional lipids prior to using the post-fermentation corn oil for industrial applications such as making biodiesel if a cost-effective recovery process can be developed. [ABSTRACT FROM AUTHOR]

Biofuels are both a promising solution to global warming mitigation and a potential contributor to the problem. Several life cycle assessments of bioethanol have been conducted to address these questions. We performed a synthesis of the available data on Brazilian ethanol production focusing on greenhouse gas (GHG) emissions and carbon (C) sinks in the agricultural and industrial phases. Emissions of carbon dioxide (CO2) from fossil fuels, methane (CH4) and nitrous oxide (N2O) from sources commonly included in C footprints, such as fossil fuel usage, biomass burning, nitrogen fertilizer application, liming and litter decomposition were accounted for. In addition, black carbon (BC) emissions from burning biomass and soil C sequestration were included in the balance. Most of the annual emissions per hectare are in the agricultural phase, both in the burned system (2209 out of a total of 2398 kg Ceq), and in the unburned system (559 out of 748 kg Ceq). Although nitrogen fertilizer emissions are large, 111 kg Ceq ha−1 yr−1, the largest single source of emissions is biomass burning in the manual harvest system, with a large amount of both GHG (196 kg Ceq ha−1 yr−1). and BC (1536 kg Ceq ha−1 yr−1). Besides avoiding emissions from biomass burning, harvesting sugarcane mechanically without burning tends to increase soil C stocks, providing a C sink of 1500 kg C ha−1 yr−1 in the 30 cm layer. The data show a C output: input ratio of 1.4 for ethanol produced under the conventionally burned and manual harvest compared with 6.5 for the mechanized harvest without burning, signifying the importance of conservation agricultural systems in bioethanol feedstock production. [ABSTRACT FROM AUTHOR]

Since 2002, the Renewable Fuels Standard has established mandated levels of ethanol blending in gasoline. Mandated ethanol use represents an important component of ethanol demand. Thus, the ethanol mandates influence derived demand for corn. This work investigates the potential impact of ethanol mandates on equilibrium corn prices and quantities, focusing on how the mandates influence market participant expectations. Results illustrate that due to the stochastic nature of supply and demand shocks, even a mandate that is technically nonbinding can have a substantial impact on corn prices and quantities through the mandate's impact on the price-responsiveness of demand from the ethanol sector. [JEL classifications: Q13, Q42, Q48]. © 2010 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

In the dry-grind corn ethanol industry, horizontal decanter centrifuges are used to separate the whole stillage into wet grains and thin stillage. The wet grains mixed with condensed thin stillage are dried to form dried distiller’s grains with solubles (DDGS). In order to investigate the effect of different corn breaking treatments on increasing oil partitioning in thin stillage, a laboratory method is needed to simulate industrial decanting where a typical thin stillage is produced. The thin stillage obtained using a conventional laboratory centrifuge had much lower solids content and less than one-half of the dry-matter yield compared to the industry counterpart because the conventional laboratory centrifuge and industry decanter centrifuge have different separation mechanisms. By evaluating the properties of industrial thin stillage and the mechanism of industrial decanter centrifugation, a laboratory decanting device was designed and a decanting procedure, the multiple-wash centrifugal filtration (MWCF) method, was developed. This method involves multiple steps of filtration under centrifugal force after washing the solids with the liquid generated from the same mash. Four cycles of MWCF produced a thin stillage with similar solids content (7.3 vs. 7.2%), dry-matter yield (54.2 vs. 54.7%), and wet yield (83.3 vs. 80.6%) compared to industrial thin stillage. The presence of ethanol did not influence the laboratory decanting results, which indicates the application robustness of this laboratory thin stillage preparation method. [ABSTRACT FROM AUTHOR]