Ethanol Industry Research Articles

Toward an Understanding of Physical and Biological Properties of Corn-Based Whole Stillage, Thin Stillage, and Condensed Distillers Solubles and Changes Thereof During Storage

The production of bio-based ethanol has been one of the fastest growing industries in the United States during the past decade. Thus, wider exploration of ethanol coproduct uses is necessary in the ethanol plant. Currently, process steams such as whole stillage, thin stillage, and syrup are processed into distiller dried grains with solubles and fed to livestock. The storability of whole stillage, thin stillage, and syrup influences the economic and energetic balances of fuel ethanol production. However, there are few investigations of the shelf life for these products or how to measure these quantities. The objectives of this research were to test physical and biological properties of whole stillage, thin stillage, and syrup and determine storability and allowable shelf life for these materials as influenced by storage temperature levels. Using standard laboratory methods, several properties were determined, including moisture content, water activity, thermal properties (conductivity, resistivity, volumetric heat capacity, and diffusivity), color, mold development, and CO2 production. Also, the separation processes due to settling were observed over 72 h. The thin stillage and whole stillage had relative high average moisture contents of 92% (w.b.) and 87% (w.b.), respectively, and a mean water activity of 0.99; the high water content marked samples easily susceptible to rapid spoilage. Time had a significant effect (p < 0.05) on properties of coproducts. Both thin stillage and whole stillage samples got mold growth after 5 days incubation at 32°C. Thin stillage had the greatest separation rate in the settling experiment. However, syrup had a relative low average moisture content of 62% and an average water activity of 0.92. No mold growth and settling separation happened in syrup samples. There was no evidence showing that a linear relationship exists between Hunter L*, a* and b*, and mold growth. The Solvita® test showed that high-temperature treatment caused high CO2 production in all samples. The exponential models described the relationship between storage time (from 0 to 5 days at 25 and 35°C) and CO2 concentration for the three coproducts. This study is a first step to explore opportunities for utilizing valuable components from these coproducts. Follow-up study should work on separation processes to concentrate the valuable components of these coproducts. Exploring the potential value of ethanol coproducts could maintain and improve the profitability of the ethanol industry.

Integration of a Network-Based and an Economy-Wide Water Model to Support Decision Making on Water Resources Planning and Management in Northeastern Brazil

Allocation of Water Resources at the basin level is a critical issue for economic growth as well as for environmental sustainability. This study integrates network-based optimization with an Input-Output model, made available through a Spatial Decision Support System (HEAL), to support design and evaluation of water allocation policies. The innovative platform was applied to a case study using four-interlinked hydrographic basins in Northeastern of Brazil. The integrated modeling was able to measure broader socioeconomic impacts of decisions on reservoir volumes and water allocations at basin level, through indicators in a sectoral and regional scale, including ones associated with Sustainable Development Goals, such as the Water Use Efficiency (WUE) indicator. Results of the trade-offs between two scenarios, representative of the limits of performance of regulatory water instruments, were generated using the integrated modeling. They were compared with the Reference scenario for the base year (2011) and show that the economic sector most negatively affected by the regulatory instrument use is the industrial sector. Furthermore, the sugar and ethanol industry, main water users in the industrial sector (93.1% of the sector's water use) and less efficient (WUE 1.47 US$/m3 vs. 30.70 US$/m3 average of the sector) in the base year, maintain their percentage share of water use in the sector and even slightly expand it (93.2%), with slight efficiency gains (+2.3%). On the other hand, non-water-intensive industries, have their shares reduced (from 6.9 to 6.8%) and lose efficiency (−9.5%). Results of the same trade-offs by region showed that the largest proportional economic losses occur in the drier areas, damaging the economy, especially in the most industrialized municipalities with the highest GDPs. Integrated economic modeling can expand aspects involved in water security issues, assisting management by introducing socioeconomic impact measures, in a broader scale, associated with allocation decisions. Hydrological allocation criteria cannot distinguish between user efficiency and which economic sectors are using how much water. This results in economic and social losses. In water-scarce regions and with growing transfer needs, such as in the basins studied, adequate incentives, through management instruments designed based on economic theory, are essential to promote sustainable development.

Lowering whole cost for sugarcane‐based ethanol production by engineered Zymomonas mobilis

AbstractLowering cost will prompt the sustainable development of sugarcane‐based ethanol industry. In this work, we developed a low‐cost process for ethanol production from sugarcane by a genetically engineered Zymomonas mobilis. Fermentation media were first optimized, resulting in a 15.54% increase in ethanol fermentation efficiency as compared to control media. To further reduce the byproduct levan formation, a levansucrase‐encoding gene of Z. mobilis, sacB, was deleted through the type I‐F CRISPR‐Cas system, which resulted in a further elevation of both ethanol conversion ratio and productivity comparing with the starting strain ZMS912 (87.50% vs. 76.77%, 1.95 g/L/h vs. 1.71 g/L/h). Moreover, we conducted fed‐batch fermentation for ethanol production using sugarcane juice in 5 L bioreactors and employing the optimized media and engineered strain. The results showed that maximum ethanol titer of 81.59 g/L and productivity of 5.83 g/L/h were achieved. Finally, preliminary techno‐economic assessment demonstrated that our efforts to modify media and strain could reduce the processing cost of ethanol production from sugarcane juice, which provides the feasibility for economic ethanol production in the future.

Industrialization progress of lignocellulosic ethanol

Lignocellulose is an abundant and renewable biomass that is mainly composed of cellulose, hemicellulose and lignin. The development and utilization of lignocellulosic ethanol is an effective way to solve the energy problem/crises, In addition, lignocellulosic ethanol industry can play a significant role in controlling environmental pollution and extending agricultural industrial chain; however, it has not been able to realize large-scale industrialization due to the limitation of both biotechnology and economy. This review first introduces industrialization status of lignocellulosic ethanol, and then focuses on the progress of practical technology and analyzing the economic feasibility of the second-generation bioethanol plant; finally, the future development trend of the industry was prospected. To summarize, continuous technological innovation is needed in vital steps such as pretreatment, enzymatic hydrolysis, and fermentation. Meanwhile, for making the cellulosic ethanol industry truly economically competitive, we also need to achieve interdisciplinary, cross-domain integration innovation, such as the construction of raw material collection and storage system, in situ producing special enzyme system, high-value utilization of raw material components, developing a closely integration of biomass refinery with mature equipment and overall industrialization programs, etc. It is hoped that this review can provide a useful reference for the industrialization of second-generation bioethanol.

Tinjauan Fatwa MUI Terhadap Penggunaan Hasil Produksi Alkohol di Sentra Industri Alkohol Bekonang

The advanced of technology and the era of global trade, affecting the number of circulation local and imported products around us. The most dangerous and widely circulating hazardous material as a mixture of industrial products is alcohol. Alcohol or ethanol production is carried out at the Bekonang alcohol industry center by fermentation and distillation that used for medical purposes, but some of the entrepreneurs tend to produce 25% alcohol or commonly called ciu which is categorized as liquor. This research was aimed to find out the practice of alcohol production in Bekonang Village, Mojolaban District, Sukoharjo Regency and the Fatwa MUI review of alcohol production practices. This study uses field research methods using a qualitative approach. The results of this study indicate that the practice of alcohol production in Sentul Village, Bekonang Village, Mojolaban District, Sukoharjo Regency processed by fermentation until distillation produces 90% alcohol or ethanol used for health. In the review of the Fatwa MUI the product of the alcohol or ethanol production process in Bekonang Village is not from Khamr, so that its use is still allowed as long as it does not cause kemudaratan. So the center of the alcohol industry in Sentul Village Bekonang Village is not the khamr industry but the pure alcohol or ethanol industry, where the production is not for drinking but for health.

Use of high protein distiller's dried grain with yeast in practical diets for the channel catfish, Ictalurus punctatus

As the ethanol industry matures and adopts new technologies, the co-products produced are also changing with their composition adjusted to meet feed industry needs. High protein distillers dried grain with yeast (HP40Y) is a relatively new product which is a variant of distillers dried grains that could be used as an improved protein source in catfish feed formulations. To evaluate the efficacy of HP40Y, a 10-weeks growth trial was conducted on the growth performance of juvenile catfish, Ictalurus punctatus (mean initial weight 1.80 ± 0.05 g). In the growth trial, graded levels of HP40Y (0.00, 3.10, 6.20 and 9.30%) were used to replace poultry meal (PM: 6.0, 4.0, 2.0 and 0.0%) and other series of diets were used with HP40Y (5.0, 10.0, 15.0, 20.0, 30.0 and 40.0%) to replace soybean meal (SBM: 51.00, 46.49, 41.90, 37.40, 28.20, 19.20%). Analysis of Covariance (ANCOVA) indicated a significant interaction between replaced protein (PM and SBM) and the inclusion level of HP40Y (up to 20%) on biomass, mean final weight, weight gain, and FCR (P < 0.05) of catfish. Therefore, the two sets of diets were analyzed separately. One-way Analysis of Variance (ANOVA) followed by Tukey multiple comparison test was used to detect significant differences between treatment means while regression analysis was used to determine the relationship between HP40Y inclusion level in the diet and weight gain and whole-body protein level of fish. In PM replacement series, complete replacement of PM with HP40Y in diet PDG9 resulted in poor performance, indicating a possible nutritional deficiency when the animal protein was removed. As a replacement for SBM, increasing levels of HP40Y only resulted in reduced growth of catfish when included in the diet at 30 and 40%. Results indicate that HP4Y is a good protein source when used at levels less than 30% of the diet.

Selected Physical and Flowability Properties of Evolving Distillers Dried Grains With Solubles (DDGS)

With the rapid development of the ethanol industry over the past few decades, research on distillers dried grains with solubles (DDGS), its main coproduct, has increased in recent years. However, research about the basic properties of DDGS lacks comprehensiveness. This study examined 16 DDGS samples from 10 ethanol plants in the Midwest U.S., and used standard laboratory methods to measure a series of physical and flowability properties. Results showed an average moisture content of 8.69% (w. b.), water activity of 0.55, angle of repose of 48.04°, shear strength of 0.0324 kg/cm2, geometric mean diameter (dgw) of 0.74 mm, geometric standard deviation (Sgw) of 1.72 mm, loose bulk density of 483.9 kg/m3, packed bulk density of 568.5 kg/m3, Hunter L of 56.71, Hunter a of 13.85, and Hunter b of 46.51. This study represents a step toward a more complete understanding of DDGS, and how various properties change as production practices evolve in the ethanol industry.

Physico-chemical profiling of edible or sweet cassava (Manihot esculenta Crantz) starches from Brazilian germplasm

Edible or sweet cassava (i.e., with cyanide content ≤ 100 mg/kg, hereinafter referred to us as sweet cassava) is a staple food and source of energy in the feed industry and for the starch and ethanol industries. To expand the industrial uses of cassava, an increased emphasis in the search for value-added traits is urged and has not been reported. In this regard, the current study aimed to investigate the Physico-chemical and pasting properties of 40 sweet cassava accessions from the Brazilian germplasm bank. The study prompts us to conclude that there is a large genetic variability among the 40 genotypes. Genotype A0-109 presented higher starch content (61.74%) and the AO-53 higher amylose content (21.65%). Genotypes 82 and A0-79 showed higher and lower swelling power respectively. In general, the typical type “A” of starch crystallinity was observed and higher starch cristallinity for genotype 54 and the lower for genotype 9. Starch from genotype AO-89 need higher pasting temperature. A large proportion of the genotypic variance contained in the phenotypic variance was obtained for pasting temperature (94%), peak viscosity (90%), breakdown, Final viscosity (88%) and amylose content (86%). Genetic advance was higher for amylose content (25.61%) and swelling power (23.98%). Generally, genotypic correlation coefficients were greater than phenotypic. This indicates that the genotypic component of variation was the major contributor to total variation in the studied traits. Genotypes with higher swelling power are suitable for use as thickeners and binding agents for food and non-food use. Those with lower setback are desirable as gelling agents in refrigerated and frozen food products, for in natura consumption or semi-processed products and can be prospected.

Co-cultivation of a novel Fusarium striatum strain and a xylose consuming Saccharomyces cerevisiae yields an efficient process for simultaneous detoxification and fermentation of lignocellulosic hydrolysates

Furfural (FF) and 5-hydroxymethylfurfural (HMF) are furan derivatives commonly generated during the pretreatment of lignocellulosic biomass and often considered among the most inhibitory compounds towards the sugar fermenting strains due to their acute toxicity and high concentrations. The present study describes the simultaneous detoxification and fermentation of lignocellulosic hydrolysates containing high concentrations of FF and HMF by a co-culture of a novel Fusarium striatum strain and a xylose consuming Saccharomyces cerevisiae strain. The process demonstrates a superior performance than those previously described in the literature, as FF and HMF were efficiently transformed into their less toxic added-value alcohol derivatives by F. striatum with high yields (99% and 86%, respectively) and the higher detoxification rates reported (0.56 g/L/h and 0.13 g/L/h, respectively). There was no sugar consumption by the filamentous fungus during the detoxification process, rendering it available for ethanol fermentation by S. cerevisiae, which started immediately after the detoxification of the inhibitors. Ethanol productivities were significantly higher when increasing the inoculum size of F. striatum, confirming its potential for the detoxification of the lignocellulosic hydrolysate. High ethanol yields (0.4 g/g) and productivities (0.46 g/L/h) were obtained in a bench-scale bioreactor (1.5 L) in the presence of 3.5 g/L HMF and 2.5 g/L FF, a concentration of furan derivatives that completely inhibited the fermentation process in the absence of F. striatum. The presented process allows access to lignocellulosic materials and pretreatment methods that result in high concentrations of FF and HMF that are currently not feasible, representing a significant advance for the lignocellulosic ethanol industry.

Isocitric Acid Production from Ethanol Industry Waste by Yarrowia lipolytica

There is ever increasing evidence that isocitric acid can be used as a promising compound with powerful antioxidant activity to combat oxidative stress. This work demonstrates the possibility of using waste product from the alcohol industry (so-called ester-aldehyde fraction) for production of isocitric acid by yeasts. The potential producer of isocitric acid from this fraction, Yarrowia lipolytica VKM Y-2373, was selected by screening of various yeast cultures. The selected strain showed sufficient growth and good acid formation in media with growth-limiting concentrations of nitrogen, sulfur, phosphorus, and magnesium. A shortage of Fe2+ and Ca2+ ions suppressed both Y. lipolytica growth and formation of isocitric acid. The preferential synthesis of isocitric acid can be regulated by changing the nature and concentration of nitrogen source, pH of cultivation medium, and concentration of ester-aldehyde fraction. Experiments in this direction allowed us to obtain 65 g/L isocitric acid with a product yield (YICA) of 0.65 g/g in four days of cultivation.

Green Composites from a Bioplastic Blend of Poly(3-hyroxybutyrate-co-3-hydroxyvalerate) and Carbon Dioxide-Derived Poly(propylene carbonate) and Filled with a Corn Ethanol-Industry Co-product.

Sustainable green composites were engineered from distillers’ dried grains with solubles (DDGS), a co-product from the corn ethanol industry as a sustainable filler in bioplastic matrices made from a carbon dioxide-derived poly(propylene carbonate) (PPC) and poly(3-hyroxybutyrate-co-3-hydroxyvalerate) (PHBV) blend. The effect of water-washed DDGS (15 and 25 wt %) on the properties of injection-molded green composites from PHBV/PPC blends (60/40) and (40/60) and DDGS without and with peroxide (0.5 phr) has been investigated. From the results, it was noticed that the glass transition temperature (Tg) of the PHBV/PPC (60/40) bioplastic matrix increased by ∼9.6 °C by adding a peroxide cross-linking agent, indicating significant interaction (linkage) between PHBV and PPC polymers in this particular composition ratio, which was supported by SEM analysis as no phase separation was observed between PHBV and PPC. The tensile modulus of PHBV/PPC (60/40) and PHBV/PPC (40/60) blends with peroxide was improved by ∼40.7 and 1.5% after the addition of 25 wt % DDGS, respectively, due to its fibrous flaky structure. The % elongation values at break of the PHBV/PPC (60/40) blend matrices with and without peroxide were drastically improved by 18.5 and 90.7 folds, respectively, as compared to that of brittle pristine PHBV.

Prices for a second‐generation biofuel industry in Canada: Market linkages between Canadian wheat and US energy and agricultural commodities

AbstractThe production of biofuels is limited in Canada, but the availability of wheat straw as a second‐generation (i.e., cellulosic) feedstock is an exciting prospect for the future development of a biofuel industry. The future success of such a biofuel industry will depend on future ethanol prices and prices related to wheat straw. These prices are likely to be influenced by markets related to the existing first‐generation ethanol industry in the United States. Therefore, the motivation of this paper is to investigate relationships between Canadian wheat prices and US corn, ethanol, and gasoline prices. We employ a DCC‐MGARCH enhanced VEC model to investigate time‐varying relationships among these markets. Results indicate that there are positive relationships between wheat and corn, ethanol and corn, and wheat and ethanol markets. Our results add to a better understanding of the level of integration between select Canadian agricultural markets and US energy markets. More specifically, the price relationships identified highlight several sources of price risk that may affect the financial success of commercially producing second‐generation ethanol from wheat straw in Canada. This information will be of particular interest to prospective industry investors and policymakers.

Bioleaching of metals from cellphones batteries by a co-fungus medium in presence of carbon materials

Today, the increased rate of electronic portable devices has led to an unprecedented amount of electronic waste. The mass production of the new generation of batteries, such as lithium-ion and lithium-ion polymer batteries used in the electronic devices releases a high volume of toxic metals to the environment, causing pollution and affecting human health. Additionally, the release of vinasse from the ethanol industry causes negative and irrecoverable effects on humans and the environment. In this paper, we investigate an innovative and eco-friendly procedure for recycling metals in lithium-ion polymer batteries in the presence of a mixed fungal culture of Aspergillus niger and Aspergillus tubingensis and pure sucrose, impure sucrose, and vinasse in three different methods: one step bioleaching, two-step bioleaching, and spent medium bioleaching. A variety of analyses, done during this investigation, indicated that the metals were recycled successfully and with high efficiency through spent medium bioleaching.

The influence of particle size of Enogen Feed corn and conventional yellow dent corn on nursery and finishing pig performance, carcass characteristics and stomach morphology.

Enogen Feed corn is a variety developed by Syngenta Seeds (Downers Grove, IL) that has been genetically modified to contain an α-amylase enzyme trait (SYT-EFC). Originally, Enogen feed corn was developed for the ethanol industry due to its reduction in viscosity of the corn mash, thus eliminating the need to add a liquid form of the α-amylase enzyme. However, there is a potential application for Enogen Feed corn to be used in livestock diets due to the increase in α-amylase enzyme potential to increase starch digestibility. A more common method of increasing starch digestibility in corn is to finely grind it to reduce particle size. This increases the surface area and allows for greater interaction with digestive enzymes. We hypothesized that pigs fed Enogen feed corn potentially could achieve similar gain:feed ratio (G:F) at larger particle sizes than conventional corn because of the differences in starch digestibility. In experiment 1, a total of 360 pigs (DNA 200 × 400, Columbus, NE; initially 6.6 ± 0.1 kg BW) were used with five pigs per pen and 12 pens per treatment. Treatments were arranged in a 2 × 3 factorial with main effects of corn source (Enogen Feed corn or conventional yellow dent corn) and ground corn particle size (300, 600, or 900 µm). Overall, there was a corn source × particle size interaction (linear, P = 0.027) for G:F. There was no effect due to particle size when pigs were fed conventional yellow dent corn, but in pigs fed Enogen Feed corn, G:F increased with decreasing particle size. Neither corn source nor particle size affected (P > 0.05) overall average daily gain (ADG) or average daily feed intake (ADFI). In experiment 2, a total of 323 pigs (241 × 600; DNA, Columbus, NE; initially 50.0 ± 1.3 kg) were used with nine pigs per pen and six pens per treatment. Treatments were identical as experiement 1. Overall, corn source had no effect on finishing pig ADG, ADFI or G:F. For corn particle size, ADG and G:F increased (linear, P < 0.014) and ADFI decreased (P = 0.043) as particle size decreased. For stomach morphology, there was a tendency for a corn source × particle size interaction (P = 0.055) for keratinization score with keratinization increasing linearly (P = 0.001) as particle size of the corn decreased for yellow dent corn with no change in keratinization score as particle size decreased for Enogen Feed corn. In summary, reducing corn particle size improved G:F with no major differences observed between corn sources for overall pig performance.

Investigating the Effects of Distillers Grains on Heifer Feeding Behavior in the Finishing Phase.

Simple SummaryDried distillers grains (DDG), a corn by-product of the ethanol industry, are a common feedstuff in cattle diets. Distillers can be used in diets as an effective source of protein and can reduce risk of acidosis by reducing the highly fermentable carbohydrate of starch. However, the price and availability of distillers grains are variable based on droughts, energy prices, and other factors. When inclusion of distillers grains in diets becomes uneconomical or is not possible, diets may decrease in crude protein and increase in starch-altering rumen fermentation parameters and feeding behavior. The effect of distillers grains on cattle growth performance and carcass traits has been studied extensively, but little is known about how distillers inclusion affects feeding behavior. Therefore, the objective of this experiment was to determine the effect of low inclusion levels of DDG on feeding behavior in heifers consuming a high-moisture corn-based diet in the finishing phase. This study demonstrated that low inclusion levels of distillers grains has little effect on growth performance, but can alter feeding behavior and reduce variability in feeding behavior traits.The objective was to determine the effect of low inclusion levels of dried distillers grains (DDG) on feeding behavior in heifers consuming a high-moisture corn-based diet in the finishing phase. Simmental × Angus heifers (N = 90; 323 ± 50 kg) were fed for 180 d. Heifers were blocked by initial body weight (BW) into two groups, stratified by sire, and assigned to 15 pens with six heifers each. Pens were randomly assigned to one of three dietary treatments: 0% DDG inclusion (0DG), 7% DDG inclusion (7DG), or 14% DDG inclusion (14DG). Treatments did not affect (p > 0.59) BW, average daily gain, and gain:feed. Although there was a treatment × time effect (p = 0.05) for dry matter intake (DMI), with 0DG having greater DMI during the last 70 d, no differences in overall DMI were detected. Treatment affected (p < 0.01) bunk visit duration and head down duration, with 7DG and 14DG having less minutes per day. Bunk visit frequency (p = 0.02) was less variable for heifers fed 14DG and DMI tended (p = 0.08) to be less variable for both distillers treatments. While dietary inclusion of DDG has minimal effects on overall heifer performance, low levels of DDG inclusion can affect feeding behavior and intake variation.

PSVI-18 Nutritional Value of High-protein Yeast Products Fed to Growing Pigs in Comparison to Commonly Used Protein Sources in Swine Diets

Abstract Alternative ingredients and co-products from the ethanol and biofuel industries represent an opportunity for utilization in swine diets. The objective of this study was to determine standardized ileal digestibility (SID) of AA in two yeast-based high protein DDGS products (HP-DDGS) fed to growing pigs in comparison to common swine diet protein sources. Cornstarch-based diets were formulated using six ingredients as the sole source of AA: spray dried HP-GDDS, ring dried HP-GDDS, conventional DDGS, soybean meal (SBM), enzymatically-treated soybean meal (HP300) and fishmeal (FM). A N-free diet was used to estimate endogenous ileal AA losses. Seven barrows (25 ± 0.8 kg BW) were fitted with a simple T-cannula at the distal ileum. The experiment was conducted as a 7 × 7 Latin square design with 7 collection periods of 7d (5d adaptation and 2d ileal digesta collection). Pigs were fed at 4% of BW. Diets and ileal digesta were analyzed for AA and titanium. Digestibility values were calculated according to the marker method. The CP and AA concentrations in Spray HP-GDDS and Ring HP-GDDS samples were higher than in the DDGS sample and similar to the SBM and HP300 samples. General SID values were within the mean +/- SD of NRC (2012) values for the six ingredients evaluated. The SID of AA was greater (P &amp;lt; 0.05) in HP300 than in the other protein sources (90.09 vs. 79.97). The SID values were generally similar (P &amp;gt; 0.05) in SBM, FM, Spray HP-GDDS, and Ring HP-GDDS samples (81.49, 78.71, 81.52, and 79.20). The SID values for Lys were greater (P &amp;lt; 0.05) in Spray HP-GDDS than in Ring HP-GDDS and DDGS (83.56 vs. 77.33 and 68.53). The HP-GDDS products are potential alternative ingredients to commonly used protein sources in swine diets and the obtained data allows its use in practical diet formulation.

Retrospective analysis of the U.S. corn ethanol industry for 2005–2019: implications for greenhouse gas emission reductions

AbstractSince 2000, corn ethanol production in the USA has increased significantly – from 1.6 to 15 billion gallons (6.1 to 57 billion liters) – due to supportive biofuel policies. In this study, we conduct a retrospective analysis of the changes in US corn ethanol greenhouse gas emission intensity, sometimes known as carbon intensity (CI), over the 15 years from 2005 to 2019. Our analysis shows a significant decrease in CI: from 58 to 45 gCO2e/MJ of corn ethanol (a 23% reduction). This is due to several factors. Corn grain yield has increased continuously, reaching 168 bushels/acre (10.5 metric tons/ha, a 15% increase) while fertilizer inputs per acre have remained constant, resulting in decreased intensities of fertilizer inputs (e.g., 7% and 18% reduction in nitrogen and potash use per bushel of corn grain harvested, respectively). A 6.5% increase in ethanol yield, from 2.70 to 2.86 gal/bushel corn (0.402 to 0.427 L kg−1 corn), and a 24% reduction in ethanol plant energy use, from 32 000 to 25 000 Btu/gal ethanol (9.0 to 6.9 MJ L−1 ethanol) also helped reduce the CI. The total GHG emission reduction benefits through the reduction in the CI and increased ethanol production volume are estimated at 140 million metric tons (MMT) from 2005 to 2019 in the ethanol industry. Displacement of petroleum gasoline by corn ethanol in the transportation fuel market resulted in a total GHG emission reduction benefit of 544 MMT CO2e during the period 2005 to 2019. © 2021 Argonne National Laboratory. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley &amp; Sons Ltd

Quantitative characterization and environmental techno-legal issues on products and byproducts of sugar and ethanol industries in Ethiopia

Characterization and quantification of the products and byproducts of the sugar and ethanol industries is an aspect of a sustainable natural resources management. The current study applied primary and secondary data collection as well as review of scenarios to quantify and characterize the products and byproducts of these industries. It also revealed the gaps in research and the relevant policies in discussing the alternative solutions available locally and globally. Currently, Ethiopia produces close to 1.8 million tons of cane sugar with over 300,000 tons of molasses as a byproduct. Using cane molasses as a raw material and with the release of 431,000 m3 of stillage into the environment, the potable ethanol industry in the country produces over 33,000 m3 of ethanol annually. Despite the expansion of sugar and ethanol industries both by the public and private owners, the environmental performance of the sector is apparently poor. These industries discharge the energy-rich “wastes streams” without proper treatment directly into the environment. Except for a few instances of the production of fuel ethanol from stillage and electricity from bagasse, the status of energy and valuables recovery from biomass in those sectors is quite lagging, which puts their sustainability at risk.

Bioprospecting of wild type ethanologenic yeast for ethanol fuel production from wastewater-grown microalgae

BackgroundWild-type yeasts have been successfully used to obtain food products, yet their full potential as fermenting microorganisms for large-scale ethanol fuel production has to be determined. In this study, wild-type ethanologenic yeasts isolated from a secondary effluent were assessed for their capability to ferment saccharified microalgae sugars.ResultsYeast species in wastewater were identified sequencing the Internal Transcribed Spacers 1 and 2 regions of the ribosomal cluster. Concurrently, microalgae biomass sugars were saccharified via acid hydrolysis, producing 5.0 ± 0.3 g L−1 of fermentable sugars. Glucose consumption and ethanol production of yeasts in hydrolyzed-microalgae liquor were tested at different initial sugar concentrations and fermentation time. The predominant ethanologenic yeast species was identified as Candida sp., and glucose consumption for this strain and S. cerevisiae achieved 75% and 87% of the initial concentration at optimal conditions, respectively. Relatively similar ethanol yields were determined for both species, achieving 0.45 ± 0.05 (S. cerevisiae) and 0.46 ± 0.05 g ethanol per g glucose (Candida sp.).ConclusionOverall, the results provide a first insight of the fermentation capacities of specific wild-type Candida species, and their potential role in ethanol industries seeking to improve their cost-efficiency.

Ethanol blending program in India: An economic assessment

ABSTRACT Importance of ethanol as a fuel has ever been increasing owing to its contribution to energy security, and carbon footprint reduction. India launched its ethanol fuel blending program in 2003 but the progress has lagged the targets despite various efforts. This study analyses the demand-supply gap in ethanol industry along with Government’s initiatives such as tax reforms, import policies and expansion of ethanol production in Indian context. The study evaluates viable ethanol prices in different scenarios and economic feasibility of second generation ethanol projects including and excluding social cost of carbon. To promote ethanol fuel blending, favorable taxation policies are helpful while ethanol import can only be a short term measure. Government’s initiatives and reforms are aligned in the right direction to promote ethanol fuel blending program. Further, growing value of social cost of carbon indicates importance of second generation ethanol production in India.