Ethanol Industry Research Articles

Evaluation of Immunological and Moisturizing Activities of beta-glucan Isolated from Molasses Yeast Waste

Systematic extraction and purification of β-glucan was attempted from molasses yeast (Saccharomyces cerevisiae) waste available from ethanol industry. The aim was to create value for the waste material by making it suitable for topical use in beauty industry. The process involved cell autolysis fractioning, solvent extraction and drying. The optimal extraction method of β-glucan gave an yield of 12.0 % (w/w) from molasses yeast waste. The β-glucan obtained was characterized using nuclear magnetic resonance spectroscopy and high-performance liquid chromatography. The effect of β-glucan on TNF-α and IL-6 levels was studied in vitro in lipopolysaccharide-activated RAW 264.7 cell line. The results indicated that β-glucan suppressed TNF-α and IL-6 production at 6 h and 24 h compared to the LPS control. Clinical evaluation of moisturizing potential of β-glucan was conducted on 22 volunteers over a period of 14 days. The results demonstrated an increase in hydration rate of 9%. The 48 h occlusive single patch test indicated that the β-glucan sample was non-irritating with mean cumulative irritation index value of 0. This study demonstrated that it is possible to create value from molasses yeast waste material, which could be industrially exploited to benefit the personal care industry in a sustainable economy.

Bio-based polyurethane foam preparation employing lignin from corn stalk enzymatic hydrolysis residues.

Enzymatic hydrolysis residues (EHR) from corn stalk are industrial waste from the cellulosic ethanol industry. Lignin was separated as a bio-based polyol from EHR replacing partial petroleum-based polyether polyol to prepare bio-based polyurethane (BPU) foams without any other biomass pretreatment. Single factor experiment and response surface methodology (RSM) were employed to optimize separation conditions and reveal the significant influence of the interaction of conditions on the yield of separated lignin (SL). The effect of SL content (2.5, 5.0, 7.5, 10 and 15%) on the foams morphology and mechanical properties was assessed. Scanning electron microscopy (SEM) results implied that the cell shape was considerably affected by the large SL content, which contributed to an irregular, inhomogeneous, and thick cell wall. An astonishing 9.56 times increase in the compressive modulus and exponential 97.93 times boost in the compressive strength of BPU foams were attributed to the content of 15% SL without any further surface chemical modification. This present paper reports a green, potential and promising method for complete utilization of lignin from EHR in consideration of their abundant supply to greatly enhance the mechanical properties of BPU foams.

Investimentos no setor sucroenergético: análise do perfil das operações automáticas de financiamento contratadas com o sistema BNDES no período de 2000 a 2015

The idiosyncrasies of the sugar-energy sector have been debated and studied exhaustively both in academia and in technical meetings, indicating challenges and opportunities that translate into a perspective of difficult visualization. Therefore, the present study aims to analyze the profile of the automatic financing operations contracted by the National Economic and Social Development Bank (BNDES) system from 2000 to 2015. Characterized as an exploratory study with a quantitative approach, the data were received directly from the BNDES via the Information Access Law (LAI). A total of 60.408 automatic operations were analyzed, with investments totaling R $ 24.714.610.364. The year 2010 had the highest investment value, representing 13,93% of the total volume of investments in the period, with 6.086 operations. The year 2009 had the highest number of operations in the period – 8.249. In addition, although the median grace period was ten years, the grace period of twelve years recorded 25.996 operations, standing out from the others. The Bank's largest disbursements were to the “Sugar Production” activity sector, followed closely by investments in “CTV Sugarcane”. There are still new expectations for the Brazilian sugar and ethanol industry.

Efficient degradation of solid yeast biomass from ethanol industry by Fenton and UV-Fenton processes applying multivariate analysis

Organic agro-industrial residues have been successfully used as biosorbents and promoting new uses from agricultural wastes benefits the economy. However, the allocation of a solid waste biosorbent after the sorption of contaminants has limited their effective application on a large scale as an alternative treatment of water and wastewaters. One solution could be degradation to convert the biosorbent material and adsorbed organic contaminants into environmental friendly compounds suitable for discharge. This study used an experimental design to evaluate the Fenton degradation of yeast biomass (YB) from the alcohol industry as a potential biosorbent. The efficiency of degradation was monitored according to the degraded mass (DM) and total organic carbon (TOC) remaining in the solution. The ANOVA showed an error of 9.7% for the effects and the media of interaction for the employed model for DM. Conducting the experiments with the best-predicted conditions (60 min, 25 g of YB, pH 3, 8,000 mg L-1 H2O2 and 40 mg L-1 Fe2+) with 30 W UV irradiation resulted in a YB reduction of 72 ± 2% with a TOC of 30 ± 2%. This suggests that an advanced oxidative process is an alternative for degradation of a biosorbent after sorption.

All-Polyamide Composite Coated-Fabric as an Alternative Material of Construction for Textile-Bioreactors (TBRs)

All-polyamide composite coated-fabric (APCCF) was used as an alternative material for the construction of textile-bioreactors (TBRs), which are prepared as a replacement of the traditional stainless steel bioreactors (SSBRs) or concrete-based bioreactors. The material characteristics, as well as the fermentation process performance of the APCCF-TBR, was compared with a TBR made using the polyvinyl chloride (PVC)-coated polyester fabric (PVCCF). The TBRs were used for the anaerobic fermentation process using baker’s yeast; and, for aerobic fermentation process using filamentous fungi, primarily by using waste streams from ethanol industries as the substrates. The results from the fermentation experiments were similar with those that were obtained from the cultivations that were carried out in conventional bioreactors. The techno-economic analysis conducted using a 5000 m3 APCCF-TBR for a typical fermentation facility would lead to a reduction of the annual production cost of the plant by $128,000,000 when compared to similar processes in SSBR. The comparative analyses (including mechanical and morphological studies, density measurements, thermal stability, ageing, and techno-economic analyses) revealed that the APCCF is a better candidate for the material of construction of the TBR. As the APCCF is a 100% recyclable single-polymer composite, which was prepared from Nylon 66 textile production-line waste, it could be considered as an environmentally sustainable product.

Trace Element Analysis of Fusel Oil by Microwave-Induced Plasma Optical Emission Spectrometry

Background: Fusel oil is a mixture of higher alcohols produced as a minor fraction of the fermentation-distillation process in sugar and ethanol industries. It can be used as a fixating agent in cosmetics products, as solvent in the food industry, or recycled as fertilizer. Considering the effects of toxic elements contamination on the quality and safety of these products, and on the environment, an efficient method for elemental fusel oil analysis may find applications in many fields. In this work, we evaluate the application of microwave-induced plasma optical emission spectrometry (MIP OES) for trace element determinations in the fusel oil matrix. Methods: Simple external calibration with standard solutions prepared in either water or 1-propanol is evaluated. Undiluted fusel oil, and 1-propanol solutions containing 5 or 50% v v-1 sample matrix are analyzed. The introduction of air into the plasma prevented potential carbon deposition on the torch and the optics, and contributed to minimizing background signals. Results: No matrix effects were observed for calibration with 1-propanol solutions even for determinations in the undiluted sample (recoveries between 90-109% for a 1.0 mg L-1 spiking level). The MIP stability requires no sample preparation, which allows for lower limits of detection (LODs) and higher sample throughput. The LODs for Cd, Cr, Cu, Ni and Pb in 1-propanol are 0.03, 0.009, 0.01, 0.007 and 0.04 mg L-1, respectively. Conclusion: The MIP OES procedure described here is a simple, accurate and precise approach to trace element analysis of fusel oil. Keywords: Nitrogen plasma, organic solvent effects, matrix effects, higher alcohols, fusel oil, copper accumulation.

Policy Uncertainty and the US Ethanol Industry

The Renewable Fuel Standard (RFS2), as implemented, has introduced uncertainty into US ethanol producers and the supporting commodity market. First, the fixed mandate for what is mainly cornstarch-based ethanol has increased feedstock price volatility and exerts a general effect across the agricultural sector. Second, the large discrepancy between the original Energy Independence and Security Act (EISA) intentions and the actual RFS2 implementation for some fuel classes has increased the investment uncertainty facing investors in biofuel production, distribution, and consumption. Here we discuss and analyze the sources of uncertainty and evaluate the effect of potential RFS2 adjustments as they influence these uncertainties. This includes the use of a flexible, production dependent mandate on corn starch ethanol. We find that a flexible mandate on cornstarch ethanol relaxed during drought could significantly reduce commodity price spikes and alleviate the decline of livestock production in cases of feedstock production shortfalls, but it would increase the risk for ethanol investors.

Simultaneous carbon and nitrogen removal from anaerobic effluent of the cassava ethanol industry

This study investigated the simultaneous carbon and nitrogen removal from anaerobic effluent of cassava stillage using a lab-scale integrated system consisting of an upflow anaerobic sludge blanket (UASB) reactor and an activated sludge (AS) process. Simultaneous denitrification and methanogenesis (SDM) was observed in the UASB with nitrate recirculation. Compared with the blank reactor without recirculation, the overall chemical oxygen demand (COD) removal efficiencies in the combined system with nitrate recirculation were similar (80-90%), while the TN removal efficiencies were significantly improved from 4.7% to 71.0%. Additionally, the anaerobic COD removal efficiencies increased from 21% to 40% as the recirculation ratio decreased from 3 to 1. Although the influent nitrate concentrations fluctuated (60-140mgN/L), the nitrate removal efficiencies could be maintained at about 97% under different recirculation conditions. With the decreasing recirculation ratio from 3 to 1, the CH4 content in biogas improved from 2% to 40% while the N2 content reduced from 95.8% to 50.6%. The 16S rDNA sequencing results indicated that bacteria diversity in anaerobic SDM granular sludge was much higher than archaea. The effect of recirculation ratios on the bacterial and archaeal communities in SDM granular sludge could be further confirmed by the relative abundance of denitrifying bacteria.

Modelling a Multi-Stage Diffuser for Sucrose Extraction in Sugarcane Biorefineries

The extraction of sugar is one of the first and main stages of sugarcane processing, and obtaining high sucrose extraction efficiencies is essential for the productivity of ethanol and sugar industries. In recent years, the number of diffusers for sucrose extraction has been increasing significantly in Brazil due to several reasons, the main ones being their higher efficiency, lower energy costs and lower maintenance and capital costs. Different factors may influence the sucrose extraction efficiency in industrial diffusers, such as operating conditions that are different from nominal equipment design conditions. Thus, the objective of this work is the modelling of a sucrose extraction process, in a multi-stage sugarcane industrial diffuser. The extraction process was first transformed into a mathematical model using phenomenological equations for the mass and momentum balance considering a lumped parameter model approach. The formulated equations were then modelled in LabVIEW and the model was tested through the analysis of the influence of the input variables in the diffuser’s extraction efficiency. Five scenarios were considered and different imbibition liquid input positions and mass flow rates, as well as different percolation liquid recirculation rates were evaluated. The results show that: (1) the insertion of imbibition liquid in more than one stage decreases the percolation velocities in most of the stages, increasing the concentration of sugar in the megasse but also increasing the concentration of sugar in the final juice; (2) higher imbibition flow rates increases the percolation velocity and, therefore, decrease sucrose concentration in the megasse. However, it dilutes the extracted juice; (3) higher recirculation rates to the same stages increase the percolation velocity and benefit sucrose extraction efficiency, decreasing the sugar concentration in the megasse and increasing the sugar concentration in the juice. Yet, a limit for the increase in recirculation must be respected in order to prevent flooding. All the obtained results were consistent and showed that the model is able to project the operation of a diffuser. In a next stage, a multi-objective optimization will be performed in order to optimize operational conditions of the equipment.

English

Wild yeasts are commonly found during the fermentation process, displaying different survival and competition strategies that commonly enable their successful spread in the medium. Identifying these yeasts by biological and molecular monitoring, and knowing their traits is vital for the fermentation yield, and this can be done by simple methods such as differential mediaplating, growth rate evaluation and DNA sequencing. The aim of this work was to perform morphophysiological and molecular characterization of 14 yeast isolates from a bioethanol plant in the State of Sao Paulo, Brazil. This was done by employing different culture media to assess the growth and the morphophysiological characteristics of the isolates. The molecular characterization was also done in order to identify the samples in intra-specific levels, compared to the reference strains. The Saccharomyces cerevisiae CAT-1 and PE-2, Brazil’s two main commercial strains, were used as reference. The results suggest that a single ethanol-producing unit may display a highly diversified microbiome, with the occurrence of distinctive wild yeast strains disclosing diverse morphophysiological traits, as observed in the differential media plating and growth rate assay results. The molecular characterization shows that these yeast isolates differ from the reference strains, as observed in interdelta-based PCR fingerprint banding patterns. These findings are a statement of the yeast diversity found in the fermentation process, and are of interest for the ethanol industry, being that many of the commercial strains were firstly isolated from the local biome. Key words: Bioethanol, differential media, growth rate, molecular characterization, morphology, Non-Saccharomyces, Saccharomyces cerevisiae.

Overview of Biogas Production Potential from Industry Sector to Produce Compressed Bio-methane Gas in Thailand

Thailand’s final energy consumption has increased continuously. The government policies used to up more alternative energy consumption in all sectors; especially the agroindustry wastes which the most of the wastewater from the production and has the potential to produce biogas. Currently, Thailand has over 1,700 biogas plants and over 150 plants of industrial waste which joined the biogas promotion project for industry supported by Energy Conservation Fund, Ministry of Energy. The projects of Thai government have been applied biogas to produce Compressed Bio-methane Gas (CBG) which for Natural Gas for Vehicles (NGV) and to replace liquefied petroleum gas (LPG) for use in industrial ceramic kilns. Biogas is an important raw material in the production of CBG. It can be used as renewable fuel in the production and transportation. So, this article presents an overview of biogas production potential from agroindustry in Thailand. The selection from 5 types of agriculture industry which was organic waste; ethanol, rubber, cassava starch, palm oil and food processing industry for the years 2008-2015. This research using secondary data of yield and wastewater quantity for a calculation to the potential of CBG production. The results show that the agroindustry has the most of CBG production potential were cassava starch, ethanol, rubber and food processing industry respectively and increasing trend.

Yeast fermentation of sugarcane for ethanol production: Can it be monitored by using in situ microscopy?

ABSTRACT This paper addresses some key issues related to the automation of fermentation process analysis in the context of industrial-scale ethanol production from sugarcane substrates. As the current methods for the determination of cell density and viability are time consuming and laborious, high resolution in situ microscopy (0.5µm) is proposed as a promising alternative. Laboratory-scale experiments presented here show that this imaging technique allows automatic, on-line, and real-time monitoring of yeast cells suspended in sugarcane molasses used in the ethanol industry. In particular, the feasibility of cell concentration measurements of Saccharomyces cerevisiae SA-1 in industrial sugarcane molasses is demonstrated. Automated concentration measurements exhibit a linear correlation with manual reference values using a Neubauer chamber from 3×106 cells/mL up to a saturation level at approximately 2×108 cells/mL. Furthermore, it was demonstrated that the microscopic resolution of this technique, combined with its large statistics, allows a morphological assessment of the size, shape and some internal structures of the yeast cells. On average, the accuracy of the algorithm´s yeast cells classification was 0.80. The results obtained suggest that the ISM is a suitable tool to perform in-line sugarcane fermentation monitoring.

Sugar and alcohol industrial waste as low-cost adsorbents: application in situ for remediation of potentially toxic metals

Filter cake, a residue from the ethanol industry, has a high content of organic matter and presents promising characteristics to act in the remediation of potentially toxic metals. The objective of this paper was to evaluate the characteristics of humic materials extracted from filter cake and investigate their interaction with toxic metals and apply to filter cake in natura and in situ. The complexation capacity of humic matter extracted from filter cakes indicated their high chelating potential and the organic matter importance in potentially toxic metals’ complexation capacity of this type of material. The humic substances extracted from filter cakes showed different affinities for potentially toxic metals (humic material Alagoas: Cr < Ni < Cd < Cu < Pb and humic material from Sao Paulo: Cd < Ni < Cr < Cu < Pb). Although the affinity order of the metals by humic material has been different from the data obtained from the controlled conditions (laboratory), “in situ” studies showed a high retention of potentially toxic metals by adsorptive materials.

Estimating the potential of energy saving and carbon emission mitigation of cassava-based fuel ethanol using life cycle assessment coupled with a biogeochemical process model.

Global warming and increasing concentration of atmospheric greenhouse gas (GHG) have prompted considerable interest in the potential role of energy plant biomass. Cassava-based fuel ethanol is one of the most important bioenergy and has attracted much attention in both developed and developing countries. However, the development of cassava-based fuel ethanol is still faced with many uncertainties, including raw material supply, net energy potential, and carbon emission mitigation potential. Thus, an accurate estimation of these issues is urgently needed. This study provides an approach to estimate energy saving and carbon emission mitigation potentials of cassava-based fuel ethanol through LCA (life cycle assessment) coupled with a biogeochemical process model-GEPIC (GIS-based environmental policy integrated climate) model. The results indicate that the total potential of cassava yield on marginal land in China is 52.51 million t; the energy ratio value varies from 0.07 to 1.44, and the net energy surplus of cassava-based fuel ethanol in China is 92,920.58 million MJ. The total carbon emission mitigation from cassava-based fuel ethanol in China is 4593.89 million kgC. Guangxi, Guangdong, and Fujian are identified as target regions for large-scale development of cassava-based fuel ethanol industry. These results can provide an operational approach and fundamental data for scientific research and energy planning.

Micro-level technological capability accumulation in developing economies: Insights from the Brazilian sugarcane ethanol industry

Accumulation of indigenous innovative capabilities in firms in developing economies (‘latecomer firms’) may contribute to sustainable industrial development. To enhance understanding of capability accumulation processes in latecomer firms, this study examines inter- and intra-firm variations in the levels and time scales of micro-level capability accumulation, related interdependencies with external organisations, and implications for innovation. Drawing on an empirically grounded study of firms from the Brazilian sugarcane ethanol industry, this study finds that the implementation of ambitious and wide-ranging innovations depends on varied internal and external capabilities. However, there are considerable variations between and within firms in their internal and external capability accumulation for specific technological functions. Firms with greater capabilities and openness undertake more ambitions innovations. Using a nuanced micro-level approach that goes beyond the firm as the main unit of observation, this study furthers understanding of the intricate, dynamic, and interdependent processes of latecomer firms' capability accumulation. It also allows deeper analysis of the implications of firms' innovative capability building for sustainable industrial development in developing economies.

Effects of low concentrations of erythromycin, penicillin, and virginiamycin on bacterial resistance development in vitro

Distillers grains are co-products of the corn ethanol industry widely used in animal feed. We examined the effects of erythromycin, penicillin, and virginiamycin at low concentrations reflective of those detected in distillers grains on bacterial resistance selection. At 0.1 µg/ml erythromycin, macrolide-resistant mutants were induced in one Campylobacter coli and one Enterococcus faecium strain, while these strains plus three additional C. coli, one additional E. faecium, and one C. jejuni also developed resistance when exposed to 0.25 µg/ml erythromycin. At 0.5 µg/ml erythromycin, a total of eight strains (four Campylobacter and four Enterococcus) obtained macrolide-resistant mutants, including two strains from each genus that were not selected at lower erythromycin concentrations. For penicillin, three of five E. faecium strains but none of five Enterococcus faecalis strains consistently developed resistance at all three selection concentrations. Virginiamycin at two M1:S1 ratios did not induce resistance development in four out of five E. faecium strains; however, increased resistance was observed in the fifth one under 0.25 and 0.5 µg/ml virginiamycin selections. Although not yet tested in vivo, these findings suggest a potential risk of stimulating bacterial resistance development in the animal gut when distillers grains containing certain antibiotic residues are used in animal feed.

Subnational mobility and consumption-based environmental accounting of US corn in animal protein and ethanol supply chains

Corn production, and its associated inputs, is a relatively large source of greenhouse gas emissions and uses significant amounts of water and land, thus contributing to climate change, fossil fuel depletion, local air pollutants, and local water scarcity. As large consumers of this corn, corporations in the ethanol and animal protein industries are increasingly assessing and reporting sustainability impacts across their supply chains to identify, prioritize, and communicate sustainability risks and opportunities material to their operations. In doing so, many have discovered that the direct impacts of their owned operations are dwarfed by those upstream in the supply chain, requiring transparency and knowledge about environmental impacts along the supply chains. Life cycle assessments (LCAs) have been used to identify hotspots of environmental impacts at national levels, yet these provide little subnational information necessary for guiding firms' specific supply networks. In this paper, our Food System Supply-Chain Sustainability (FoodS3) model connects spatial, firm-specific demand of corn purchasers with upstream corn production in the United States through a cost minimization transport model. This provides a means to link county-level corn production in the United States to firm-specific demand locations associated with downstream processing facilities. Our model substantially improves current LCA assessment efforts that are confined to broad national or state level impacts. In drilling down to subnational levels of environmental impacts that occur over heterogeneous areas and aggregating these landscape impacts by specific supply networks, targeted opportunities for improvements to the sustainability performance of supply chains are identified.

Sugarcane ethanol industry effects on the GDP per capita in the Center-South region of Brazil

The demand growth for biofuels worldwide led to a significant increase in the Brazilian sugarcane ethanol industry from the 2000’s. This scenario affected specially the Center-South region of Brazil, which comprises the states of São Paulo, Paraná, Minas Gerais, Mato Grosso do Sul, Mato Grosso, and Goiás, as well as the Federal District of Brasília, because it surpasses all other regions of the country in terms of the production and production facilities. Therefore, the aim of this study is to quantify the sugarcane ethanol industry effects on the per capita municipal gross domestic product (GDP) in the Center-South region of Brazil, for the 2000-2012 period. To that end, we estimated two econometric models, using panel data models and quantile regression. The results show that sugar ethanol industry has an important effect on GDP per capita for the Center-South region municipalities, furthermore the effects are more intensive on the lowest municipalities levels of the per capita GDP, thus being able to provide support for making public policy.

Biomass Production a Stronger Driver of Cellulosic Ethanol Yield than Biomass Quality

Core Ideas Fermentable sugars were greatest in corn stover &gt; perennial grasses &gt; polycultures. Corn stover had the highest ethanol content. Miscanthus had the highest ethanol yield potential on a per hectare basis. Ethanol yield potential per hectare of switchgrass ≥ corn stover. Biomass yield was the strongest driver of per hectare ethanol yield. Many crops have been proposed as feedstocks for the emerging cellulosic ethanol industry, but information is lacking about the relative importance of feedstock production and quality. We compared yield and sugar content for seven bioenergy cropping systems in south‐central Wisconsin (ARL) and southwestern Michigan (KBS) during three growing seasons (2012 through 2014). The cropping systems were (i) continuous corn stover (Zea mays L.), (ii) switchgrass (Panicum virgatum L.), (iii) giant miscanthus (Miscanthus × giganteus Greef &amp; Deuter ex Hodkinson &amp; Renvoize), (iv) hybrid poplar (Populus nigra × P. maximowiczii A. Henry ‘NM6’), (v) native grass mix, (vi) early successional community, and (vii) restored prairie. A high‐throughput pretreatment and fermentation assay showed corn stover with the highest sugar content (213 g glucose kg−1 [Glc] and 115 g xylose kg−1 [Xyl]) followed by the two monoculture perennial grass treatments (154 [Glc] and 88 [Xyl]) and then the herbaceous polycultures (135 [Glc] and 77 [Xyl]). Biomass production and sugar content were combined to calculate ethanol yields. Miscanthus had the highest per hectare ethanol yields (1957 l ha−1 yr−1 ARL, 2485 l ha−1 yr−1 KBS) followed by switchgrass (1091 l ha−1 yr−1 ARL, 1017 l ha−1 yr−1 KBS) and corn stover (1121 l ha−1 yr−1 ARL, 878 l ha−1 yr−1 KBS). Perennial grass cropping systems (i.e., switchgrass and miscanthus) had higher per hectare ethanol yields at both sites relative to diverse systems that included dicots. Despite feedstock differences in fermentable sugars, biomass production was the strongest driver of per hectare ethanol yield.

Maximizing cellulosic ethanol potentials by minimizing wastewater generation and energy consumption: Competing with corn ethanol

Energy consumption and wastewater generation in cellulosic ethanol production are among the determinant factors on overall cost and technology penetration into fuel ethanol industry. This study analyzed the energy consumption and wastewater generation by the new biorefining process technology, dry acid pretreatment and biodetoxification (DryPB), as well as by the current mainstream technologies. DryPB minimizes the steam consumption to 8.63GJ and wastewater generation to 7.71tons in the core steps of biorefining process for production of one metric ton of ethanol, close to 7.83GJ and 8.33tons in corn ethanol production, respectively. The relatively higher electricity consumption is compensated by large electricity surplus from lignin residue combustion. The minimum ethanol selling price (MESP) by DryPB is below $2/gal and falls into the range of corn ethanol production cost. The work indicates that the technical and economical gap between cellulosic ethanol and corn ethanol has been almost filled up.