Ethanol Industry Research Articles

Portable colorimetric photonic indicator for ethanol concentration sensing

Colorimetric sensing of ethanol concentration accelerates the intellectualization of the ethanol industry. The development of alcohol detectors with excellent structural color output and reconfigurable nanostructures will certainly set off reform in colorimeter sensors. Here, a novel portable colorimetric photonic indicator (CPI) that can distinguish alcohol with concentrations from 0 to 100 % was ingeniously fabricated by bridging the copolymer capable of autonomic solvent control with porous structure via shape memory photonic crystals (PCs). CPI shows an ultrafast color response (<1 s) to the perception of ethanol concentration and outputs structural colors from blue to red, with reflection covering ∼477 to ∼628 nm. The coloration and color-change mechanisms of CPI are derived from the hydrogen bonds remodeling among carboxyls, ethylene glycol groups, and solvent molecules, the shape memory effect of the inverse opal skeleton, and the reversible structural transformation induced by the solvent co-solvency effect. We validate the real-time visual concentration-detection capabilities of CPI by measuring the distillate concentration during the alcohol distillation. We envisage that CPIs show potential applications in automated and broad-spectrum molecule-detection devices in biomedical and chemical engineering.

Characterization of an endo-beta-1,4 glucanase gene from paper-degrading and denim bio-stoning cellulase producing Aspergillus isolates.

Cellulases are used in textile, pulp and paper, brewery and wine, sugars, and ethanol industries. Four fungal isolates obtained from organic municipal solid wastes (OMSW) were selected based on their cellulolytic activity on carboxymethyl cellulose (CMC) agar medium. Based on the internal transcribed spacer (ITS) sequence of the ribosomal DNA, the four cellulolytic isolates were identified as Aspergillus fumigatus AKAL1, Aspergillus oryzae AKAL4, Aspergillus flavus AKAL8, and Aspergillus flavus AKAL9. After 9 days of fermentation at 30°C and pH 6.5 under 110rpm agitation, these isolates produced the maximum amount of cellulase. The cellulase showed optimum activity at temperature 35-40°C and pH 6.0-7.0 and was stable for 1h at 25-45°C and pH 5.0-7.0. The Mg2+ and Zn2+ significantly increased but Hg2+ , K+ , and Ca2+ severely repressed the cellulase activity. Degradation of filter papers and bio-stoning of denim was successfully done with the crude cellulase. An endo-β-1,4-glucanase was isolated and characterized from Aspergillus isolates. Genome-wide analysis revealed that the genomes of A. oryzae, A. fumigatus, and A. flavus, the pertinent species of the fungal isolates, had 23, 25, and 22 cellulase genes, respectively. Phylogenetic analysis revealed that the cellulases in these fungal species were divided into three major groups, and the isolated endo-β-1,4-glucanase clustered to Group II. Ten different motifs are present in cellulases of the three species. Results herein provide a valuable resource for understanding cellulase genes in Aspergillus species and potential application of cellulase in textile and fermentable sugars production industries.

Treatment of Sugarcane Vinasse Using Heterogeneous Photocatalysis with Zinc Oxide Nanoparticles

Vinasse is the main by-product of the ethanol industry; for each liter of ethanol, 13 to 18 L of vinasse is generated. Vinasse is composed of 93% water and 7% organic and inorganic solids and has an acidic pH and a high concentration of macro- and micronutrients used by plants, which is the reason for its widespread application in soil fertigation. However, over time, excessive direct discharge of vinasse into the soil causes damage, such as salinization and groundwater contamination. In this study, we used heterogeneous photocatalysis with zinc oxide nanoparticles (ZnO-NPs) to reduce chemical oxygen demand (COD) and biochemical oxygen demand (BOD) and as an antimicrobial treatment. ZnO-NPs were synthesized by the precipitation of zinc sulfate heptahydrate and sodium hydroxide, resulting in nanoparticles with a size of 21.6 ± 0.3 nm and an energy bandgap of 2.6 eV. Microscopic examinations revealed that Saccharomyces cerevisiae microorganisms are present in vinasse and that the minimum inhibitory concentration for the ZnO-NPs is 1.56 g/L. Photocatalysis with 40 mg/L of ZnO-NPs for 4 h of exposure to sunlight resulted in COD and BOD reduction efficacies of 17.1% and 71.7%, respectively. This study demonstrates the viability of using ZnO-NPs in vinasse treatment, contributing to sustainable applications and reducing the environmental impacts of fertigation.

Lignin Gasification: Current and Future Viability

The consumption of fossil fuels is one of the main drivers of climate change. Lignin derived from biomass is a carbon-neutral raw feedstock, and its conversion into fuels is gaining much attention. The gasification of biomass aims to transform heterogeneous feedstocks into syngas and heat that could be used for various purposes. Lignin is a biomass feedstock of special interest due to its particular properties and its ability to be obtained in abundant quantities as a side product from the paper pulp industry as well as the growing cellulosic ethanol industry. This review explores the existing works regarding lignin gasification from different perspectives and compares the results obtained with other existing thermochemical processes, in addition to providing a perspective on the long-term fate of gasification as a technology compared to other emerging technologies. The analysis indicates that while lignin gasification may grow in importance in the near future due to increased interest in hydrogen production, its potential in emerging applications indicates that lignin may be too valuable to be used purely for energy generation purposes, and applications that take advantage of its inherent chemical compounds are expected to take priority in the long-term.

Evaluation of High‐Protein Distillers Dried Grains with Yeast as a Protein Source in Practical Diets for Pacific White Shrimp Litopenaeus Vannamei

AbstractIncreasing worldwide competition and shifts in demand, technological advancements, and innovative findings out of research are triggering the ingredient manufacturing industry to include modified processing technologies and novel ingredients. New technologies have been introduced by the ethanol industry to improve the efficiency of ethanol production, resulting in new types of distillers dried grains with different nutrient profiles. One of the new processing techniques removes fibrous corn components before fermentation and removes the soluble fraction after fermentation to produce a high‐protein distillers grain with yeast (HP50Y with 49% protein and HP40Y with 40% protein). The current study was conducted to evaluate the efficacy of HP50Y and HP40Y as a replacement for corn protein concentrate (CPC) in diets of Pacific white shrimp Litopenaeus vannamei. In the first diet series, graded levels of HP50Y (0.0, 5.0, 10.0, 15.0, and 20.0%) were used to replace CPC (13.1, 10.0, 6.6, 3.5, and 0.2%). In the second diet series, graded levels of HP40Y (5.0, 10.0, 15.0, and 20.0%) were used to replace CPC (10.5, 8.0, 5.5, and 2.5%). These diets were evaluated over a 40‐d growth trial (initial weight = 0.54 ± 0.01 g; n = 4). At the conclusion, no significant differences were detected in growth, feed conversion ratio, survival, and food consumption of Pacific white shrimp (P‐value &gt;0.05). However, results from regression analysis revealed that there was a significant increase in percent weight gain of Pacific white shrimp as the percent inclusion level of HP50Y and HP40Y increased in the shrimp diets. Results indicate that HP50Y and HP40Y are both good protein sources and can be used up to a 20% inclusion level in the diets of Pacific white shrimp.

Effects of rice husk on the tolerance of Saccharomyces cerevisiae to high temperature and ethanol concentration

In recent years, growing attention has been devoted to improving stress resistance of yeast to temperature and ethanol concentration as it affects fermentation productivity in biofuel ethanol industry. Rice husk was found to increase the resistance of yeast to high temperature and high ethanol concentration, which can be attributed to yeast cell adsorption on rice husk. Compared with no addition of rice husk, the ethanol yield of brown rice fermented at 32 °C and 39 °C with 1.0 % rice husk increased by 9.4 % and 5.1 %. The fermentation kinetics of cell growth and ethanol formation could be described by the improved Logistic model and Luedeking-Piret model, respectively. Based on the effect of rice husk, the higher ethanol concentration (106.7 g/L at 32 °C) and complete substrate utilization could be achieved by using a mixed substrate at dry mass ratio of whole rice to brown rice of 3:1.

Responses of Chironomus sancticaroli to the simulation of environmental contamination by sugarcane management practices: Water and sediment toxicity

Sugarcane management practices include the application of pesticides, including the herbicide 2,4-D and the insecticide fipronil. In addition, a by-product from the ethanol industry, called vinasse, is commonly applied to fertilize sugarcane areas. The potential risks of these practices to the edge-of-field aquatic ecosystems were assessed in the present study. This was done by contaminating mesocosms with (single and mixtures of) both pesticides and vinasse and evaluating the effects on the midge Chironomus sancticaroli through in-situ and laboratory bioassays. To this end, outdoor mesocosms were treated with fipronil (F), 2,4-D (D), and vinasse (V) alone and with the mixture of fipronil and 2,4-D (M), as well as with both pesticides and vinasse (MV). C. sancticaroli was deployed in mesocosms before contamination in cages, which were taken out 4- and 8-days-post-contamination. Water and sediment samples were also taken for laboratory bioassays on the first day of contamination, as well as 7-, 14-, 21-, 30-, 45-, and 75-days post-contamination. The responses assessed in subchronic assays (8-day) were survival, growth, head capsule width, development, and mentum deformities. Low survival occurred in the in-situ experiments of all treatments due to the low oxygen levels. In the laboratory tests, effects on survival occurred for F, V, and M over time after exposure to both water and sediment. All organisms died post-exposure to water samples from the MV treatment, even 75-days-post-contamination. Impairments in body length and head capsule width occurred for F, V, and M for water and F, V, M, and MV for sediment samples over time. All treatments increased mentum deformities in exposed larvae for any of the sampling periods. The negative effects observed were more significant in the mixture mesocosms (M and MV), thus indicating increased risks from management practices applying these compounds together or with a short time interval in crops.

Evaluation of graded levels of corn-fermented protein on stool quality, apparent nutrient digestibility, and palatability in healthy adult cats.

Dried distillers' grains, coproducts from the ethanol industry, may provide sustainable ingredients for pet food. Due to new post-fermentation separation techniques, corn-fermented protein (CFP) is higher in protein and lower in fiber compared with traditional dried distillers' grains, increasing its appeal for inclusion into pet food. Therefore, the objectives of this study were to determine the effects of increasing levels of CFP on stool quality, apparent total tract digestibility (ATTD), and palatability in adult cats. Four extruded diets were fed to 11 adult cats in an incomplete 4 × 4 replicated Latin square design. The control diet contained 15% soybean meal (0C) and CFP was exchanged for soybean meal at either 5%, 10%, or 15% (5C, 10C, 15C). Cats were fed each dietary treatment for 9-d adaption followed by 5-d total fecal collection. Feces were scored on a 1 to 5 scale, with 1 representing liquid diarrhea and 5 representing hard pellet-like (Carciofi et al., 2008). A fecal score of 3.5 to 4 was considered ideal. Titanium dioxide was added to all diets (0.4%) as a marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and cat and period as random effects. Fecal dry matter percent and dry fecal output were greater (P < 0.05) at elevated levels of CFP. Stool scores were maintained (P > 0.05) throughout treatments (average; 4). Dry matter, organic matter, crude protein, and gross energy ATTD decreased when cats were fed 15C. There was no difference in ATTD of fat or total dietary fiber among treatments. For palatability assessment, cats preferred 5C over 0C but had no preference with increased CFP inclusion. These results suggest that CFP is comparable to SBM, but there may be a maximum inclusion level of 10% when fed to cats.

Advancements and prospectives of sugar beet (Beta vulgaris L.) biotechnology.

Sugar beet (Beta vulgaris L.) is the second largest sugar-producing crop (following sugarcane), accounting around 40% of total global sugar output. It has been reckoned with huge contribution in sugar, ethanol, and fodder industries. Since sugar beet is recalcitrant in nature, to address the multifaceted difficulties associated with its conventional propagation, several biotechnological tools and techniques aiming with in vitro-based mass regeneration-cum-genetic enhancement are becoming popular. The implementation of effective methodology for in vitroregeneration from ex vitro explant sources becomes the necessity for successful commercial-scale clonal propagation and genetic modification. Substantial research achievements have been made in the past few decades in connection to the optimization of in vitro protocols for direct and callus-mediated regeneration, homozygous line production, somatic hybridization, and genetic transformation of sugar beet. The current review summarizes several reported findings on various physio-chemical factors responsible for direct, indirect organogenesis, somatic embryogenesis, protoplast culture, haploid culture, acclimatization accountable for plantlet mass multiplication, assessing the genetic integrity of in vitro-cultured plantlets, and, finally, successful transgenic approaches to remediate biotic and abiotic stresses. Furthermore, this study highlights undiscovered regions, research gaps, and major bottlenecks that might be considered in developing significant innovative ideas related to sugar beet biotechnology in the near future. KEY POINTS: • Sugar beet, the second largest sugar producer, is a major contributor in sugar, ethanol, and fodder industries. • Current review comprehensively evaluates diverse factors influencingthe success of in vitro biotechnological interventions. • This review further highlights the research gaps and offers way outs to attain comprehensive genetic improvement.

Equilibrium and real options in the ethanol industry: Modeling and empirical evidence

In the last twenty years a large number of ethanol firms have established operations in the US. Ethanol, produced from corn, is blended with pure gasoline to produce fuel. Producers hold an option to turn off unprofitable plants. Blenders choose to substitute ethanol for gasoline at or beyond the mandate set by the government. We propose an equilibrium model for blenders and producers that accounts for government measures and for real optionality embedded in the industry. The model, driven by corn and gasoline prices, leads to analytical expressions for the price and output of ethanol, and to policy implications on the impacts of the mandate and blend credit. The model also leads to closed form valuation for an ethanol producer. Using data between 2000 and 2017 we confirm that, as in the model, ethanol was largely priced as the maximum of rescaled gasoline and corn prices. Historical output levels between the mandate and installed capacity were explained by our theory. Finally, the share price dynamics for the largest public ethanol producer in the US was consistent in some aspects with the value of a real option.

Thermal treated sugarcane bagasse for acetylsalicylic acid removal: dynamic and equilibrium studies, cycles of reuse and mechanisms

ABSTRACT Sugarcane bagasse, an abundant residue from ethanol and sugar industry, was used in its natural form (SB) and carbonised (CS) as adsorbent for removing acetylsalicylic acid from aqueous solutions. The surface area, porosity, functional groups and surface charges of the adsorbents were characterised by Brunauer–Emmett–Teller and Barret–Joyner–Halenda methods, Fourier transform infrared spectroscopy and point of zero charge. Analysis indicated that C- and O-containing functional groups may be involved in the adsorption process. Batch experiments were also performed to evaluate the effects of pH, temperature and time on the sorption. The materials exhibited high adsorption efficiency at low pH. Results revealed that the pseudo-first-order kinetic model and pseudo-second-order provided the best fitting to the experimental data for biosorbent SB and biochar CS, respectively. Liu isotherm model describes the adsorption equilibrium for biochar suggesting that the carbonised surface had a heterogeneous nature with Q max of 32.73 mg g−1 at 298 K. Besides, intraparticle diffusion model suggests that adsorption of ASA onto activated carbon was controlled by multiple steps. This study demonstrated that carbonised sugarcane bagasse is a potential adsorbent for removing acetylsalicylic acid from aqueous solutions.

121 Comparison of Corn Fermented Protein (CFP) to Traditional Yeast and Distillers Grain fed to Healthy Adult Cats

Abstract Co-products from the ethanol industry may be able to provide high-quality sustainable protein sources for pet foods. Unlike traditional co-products, corn fermented protein (CFP) contains a yeast component which may provide additional benefits. The objective of this study was to determine, by exchange, the effects of the yeast in corn fermented protein on diet utilization. The four experimental diets included a control with no yeast (CON) and diets containing either 3.5% brewer’s dried yeast (BDY), 17.5% distiller’s dried grains with solubles plus 2.5% brewer’s dried yeast (BDY+DDGS), or 17.5% CFP (CFP). It was assumed that CFP contained 20% yeast and all treatments except CON were formulated to contain 3.5% yeast. Experimental diets were fed to adult cats (n = 11) in a replicated 4 x 4 Latin Square design. Cats were adapted to diet for 9 days followed by a 5-d total fecal collection. Titanium dioxide (0.4%) was added to all diets as a marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and cat and period as random effects. Dry fecal output of cats was greatest for BDY+DDGS at 20.2 g/d compared with the other treatments at an average of 16.3 g/d (P &amp;lt; 0.05). Defecations per day were also greatest for cats consuming BDY+DDGS (P &amp;lt; 0.05). When comparing CFP with BDY+DDGS, the digestibility of dry matter, organic matter, and gross energy was about 3% greater (P &amp;lt; 0.05) for CFP. Short or branched chain fatty acids in fecal samples were not altered by dietary treatment. The increase in fecal output and decrease in digestibility with BDY+DDGS indicates a greater fiber effect in the DDGS compared with the CFP. Therefore, the yeast component in CFP may be providing a greater nutrient utilization when fed to cats.

Leaves from four different sugarcane varieties as potential renewable feedstocks for second-generation ethanol production: Pretreatments, chemical composition, physical structure, and enzymatic hydrolysis yields

Development of Bioeconomy is impossible without establishing efficient technologies of lignocellulosic biomass valorization via transformation into fermentable sugars. Sugarcane is a valuable agricultural crop in several Asian, African, and Latin American countries. Here, leaves from two sugarcane and two energy cane varieties were evaluated for sustainable production of second-generation sugars, and their enzymatic hydrolysis yields were compared. Structural, morphological, and chemical composition changes in sugar and energy cane leaves submitted to acid, and acid-alkaline pretreatments were analyzed using X-ray diffraction, scanning electron microscopy, confocal laser microscopy, high-performance liquid chromatography, and low-field solid-state NMR techniques. Enzymatic hydrolysis assays were conducted to evaluate saccharification yields of untreated and pretreated leaves. Jointly, our results revealed the significant potential of leaves from two commercial sugar cane cultivars currently bred in Argentina as possible lignocellulose substrates for the 2G ethanol industry.

Brazilian industrial yeasts show high fermentative performance in high solids content for corn ethanol process

An imminent change in the world energy matrix makes it necessary to increase the production of renewable fuels. The United States and Brazil are the world's largest producers, but their production methods are very different, using different raw materials, ground corn and sugarcane juice, respectively. In recent years, strong investments have been made to expand the use of corn in Brazilian ethanol production. The combination of the sugar cane and corn ethanol industries has generated innovations in the sector, such as the "flex" mills, which are traditional sugar cane mills adapted to produce corn ethanol in the sugar cane off-season. Brazil has a portfolio of robust industrial yeasts for sugarcane ethanol production, naturally evolved and selected over the past 50 years. In this work, we analyze for the first time the performance of Brazilian industrial strains (BG-1, CAT-1, PE-2 and SA-1, widely used in sugarcane ethanol production) in corn ethanol production using different stress conditions. Ethanol Red yeast, traditionally used in corn ethanol plants around the world, was used as a control. In terms of tolerance to temperature (35 °C), strains BG-1 and SA-1 stood out. In fermentations with high solids concentration (35%), strain BG-1 reached ethanol contents higher than 19% w/v and had a productivity gain of 5.8% compared to fermentation at 30%. This was the first time that these industrial strains were evaluated using the high solids concentration of 35% and the results point to ways to improve the corn ethanol production process.Graphical

Price volatility spillovers between Canadian and US, agricultural and fuel markets

A good understanding of risk transmission between agricultural and energy industries can be important to the sustainability of agriculture and the development of renewable energy industries. Literature has shown that the volatility of international agricultural and energy markets has mutual influences, and that these influences may change over time and space. This analysis adds value to the literature by identifying whether, and to what extent, price and volatility spillovers exist between the Canadian wheat market and US corn and energy markets (i.e. gasoline and ethanol). Though many studies have investigated pass-through between corn and energy markets, the addition of wheat markets in Canada is of interest because of the increasing use of wheat in producing first generation ethanol, and the potential for second generation ethanol that could use Canadian wheat straw as a feedstock. Our investigation adopts a modified vector error-correction model with a multivariate generalized autoregressive conditional heteroskedasticity framework. Key results include: (1) wheat and ethanol prices adjust to a deviation in the equilibrium relationship with corn and gasoline prices; (2) price volatility in the wheat market is only affected by its own shocks, not by the spillovers from US corn, ethanol or gasoline markets; (3) corn price volatility is not affected by shocks to wheat, ethanol, or gasoline markets. However, corn price volatility is largely affected by the covariance between wheat and corn. This information is useful for developing business strategies, as well as for policy makers interested in the development of a second-generation wheat straw-based ethanol industry in Canada. Our results also improve the understanding of impacts of US energy policies on Canada.

Is ethanol production responsible for the increase in corn prices?

This paper aims to investigate the effects of the production of ethanol, a renewable biofuel, oil prices, population, and exchange rate on corn prices in the US (1985:m1-2020:m7) using a nonlinear smooth transition model. According to the findings, (i) ethanol production (β1 = 0.072, p < 0.01) has an increasing effect on corn prices. (ii) Oil prices (β2 = 0.064, p < 0.05) and population (β3 = 0.851, p < 0.01) put a pressure on corn prices. (iii) The increase in the real exchange rate (β4 = −2.142, p < 0.01) has a decreasing effect on corn prices. The estimation results provide several critical policy implications for ethanol-food competition within the framework of sustainable development policies. First, ethanol production puts pressure on corn prices. Second, policy-oriented research on the biofuel-food competition can provide guidance to ensure sustainability. Finally, in the transformation process of the ethanol industry, technological innovations (use of second or third-generation biofuels) can moderate the food-fuel nexus.

The Environmental Profile of Ethanol Derived from Sugarcane in Ecuador: A Life Cycle Assessment Including the Effect of Cogeneration of Electricity in a Sugar Industrial Complex

The present study compiles a life cycle inventory for Ecuadorian sugarcane-derived ethanol production to quantify its environmental performance and identify the life cycle stages that cause major impacts. The scope of this study encompasses a cradle-to-gate analysis that includes the agriculture, the milling, the distillation, and the co-generation of electricity. This assessment is modeled using the OpenLCA v1.10.3 software. Two functional units (FU) were established in this study: “1 ton of sugarcane at-the-farm-gate” for the agricultural stage and “1 L of ethanol at-the-plant-gate”. A hybrid attributional and consequential life cycle analysis (LCA) approach has been followed. Economic allocation (EA) and system expansion (SE) were used to take co-products into account in the milling and co-generation of electricity stages, respectively. The co-generation stage is analyzed in three different scenarios: (i) average mix displacement scenario where the surplus electricity produced in the co-generation stage is displaced; (ii) marginal technology displacement scenario where the marginal surplus electricity is displaced from the mix and (iii) no displacement scenario. The global warming potential (GWP) impact at the farm gate level was reported as 53.6 kg of carbon dioxide equivalent (kg CO2eq.) per ton of sugarcane produced. The two main contributors of the agricultural stage correspond to N2O lixiviation and volatilization with 34% followed by the diesel used in agricultural machinery with 24%. The GWP for 1 L of ethanol produced was reported as 0.60 kg CO2eq. based on the average mix displacement scenario. No displacement scenario has a GWP impact of 0.84 kg CO2/liter of ethanol The distillation stage has the highest contribution to GWP impact with approximately 61% followed by the agricultural stage with 47%. The co-generation stage reports a contribution of −8.4% due to the surplus electricity displacement. The scenarios where the system expansion method is applied have a lower GWP impact compared to the scenario where no surplus electricity is displaced. Regarding terrestrial acidification potential impact, 0.01528 kg of SO2eq. was reported at the ethanol production level especially due to the nitrogen and phosphorous content in the vinasse produced from the distillation process. The marine eutrophication impact for 1 L of ethanol produced was 0.00381 kg of Neq. due to the content of nitrogen contained in the vinasse and the use of nitrogenous fertilizers in the agricultural stage. Finally, to create more eco-friendly Ecuadorian sugarcane and ethanol industries, sustainable and less polluting processes should be sought to reduce the environmental burdens. Companies should apply industrial symbiosis and circular economy strategies to produce lesser environmental loads within the ethanol production chain. The sugarcane industrial sector should also promote the surplus electricity production in order to gain credits.

Agricultural Structures Management Based on Nonpoint Source Pollution Control in Typical Fuel Ethanol Raw Material Planting Area

Increasing the promotion and application of biofuel ethanol has been a national strategy in China, which in turn has affected changes in the raw material planting structure. This study analyzed the effects of agricultural land-use changes on water quality in a typical maize fuel ethanol raw material planting area. The results revealed that an increase in cultivated land and construction land would also increase the load of TN (total nitrogen) and TP (total phosphorus), while an expansion in forest land would reduce the load. As for crop structures, maize might have a remarkable positive effect on TN and TP, while rice and soybean performed in no significant manner. Furthermore, scenarios under the carbon neutralization policy and water pollution control were carried out to forecast the nonpoint source pollutants based on the quantitative relations coefficients. It was proven that maize planting was not suitable for vigorous fuel ethanol development. Reducing maize area in the Hulan River Basin was beneficial to reducing nonpoint source pollution. However, the area of maize should not be less than 187 km2, otherwise, the food security of the population in the basin would be threatened. Under the change in fuel ethanol policy, this study could provide scientific support for local agriculture land-use management in realizing the carbon neutralization vision and set a good example for the development of the fuel ethanol industry in other maize planting countries.

Pathway to a land-neutral expansion of Brazilian renewable fuel production

Biofuels are currently the only available bulk renewable fuel. They have, however, limited expansion potential due to high land requirements and associated risks for biodiversity, food security, and land conflicts. We therefore propose to increase output from ethanol refineries in a land-neutral methanol pathway: surplus CO2-streams from fermentation are combined with H2 from renewably powered electrolysis to synthesize methanol. We illustrate this pathway with the Brazilian sugarcane ethanol industry using a spatio-temporal model. The fuel output of existing ethanol generation facilities can be increased by 43%–49% or ~100 TWh without using additional land. This amount is sufficient to cover projected growth in Brazilian biofuel demand in 2030. We identify a trade-off between renewable energy generation technologies: wind power requires the least amount of land whereas a mix of wind and solar costs the least. In the cheapest scenario, green methanol is competitive to fossil methanol at an average carbon price of 95€ tCO2−1.

Mechanism of Response of Watershed Water Quality to Agriculture Land-Use Changes in a Typical Fuel Ethanol Raw Material Planting Area-A Case Study on Guangxi Province, China.

Speeding up the promotion and application of biofuel ethanol has been a national strategy in China, which in turn has affected changes in the raw material planting structure. This study analyzed the response mechanism of water quality to agriculture land-use changes in a cassava fuel ethanol raw material planting area. The results revealed that an increase in cultivated land and construction land would lead to a rise in the load of TN (total nitrogen) and TP (total phosphorus), while an expansion in forest land and grassland area would reduce the load. As for crop structures, corn would have a remarkable positive impact on TN and TP, while rice and cassava performed in an opposite manner. Furthermore, scenarios under the carbon neutralization policy were carried out to forecast the nonpoint source pollutants based on the quantitative relations coefficients. It was proven that cassava planting was suitable for vigorous fuel ethanol development, but the maximum increase area of cassava should be 126 km2 to ensure economic benefits. Under the change in fuel ethanol policy, this study could provide scientific support for local agriculture land-use management in realizing the carbon neutralization vision and also set a good example for the development of the cassava fuel ethanol industry in other cassava-planting countries.