Ethanol Production Technology Research Articles

Potential solution to the sustainable ethanol production from industrial tail gas: An integrated life cycle and techno-economic analysis

Utilising industrial tail gas for ethanol production is a viable pathway to significantly mitigate CO2 emissions whilst simultaneously producing value-added fuels and chemicals, which has received great attention in recent years. While some technologies have been commercial deployed, new technological concepts continue to emerge in order to improve the life cycle and techno-economic performance. In this investigation, a novel ethanol production technology integrating tail gas-based ethanol (TG-ethanol) with electro-catalytic CO2 reduction (ECR), called TGEE technology, was first proposed to address the energy and carbon efficiency issues associated with the state-of-the-art TG-ethanol technologies. The process was modularly modelled for to accommodate different ECR integration scenarios for three typical industrial tail gas streams (steel, iron alloy and calcium carbide). In addition, life cycle & techno-economic analysis based on Monte Carlo simulation were employed to evaluate the environmental and economic performance of the TGEE process. Results show that ethanol capacity can be increased by 1.3–2.9 times with carbon efficiency up to 36–82%. Life cycle carbon footprints of TGEE-ethanol were estimated to be 1.77–3.93 t CO2eq/t ethanol, with a carbon reduction potential of 32–63% higher than the TG-ethanol. Minimum ethanol selling price is estimated to be 428–962 $/t ethanol, which is lower than the current ethanol market price (900–1080 $/t). Overall, the comprehensive analysis suggests that the TGEE process emerges as a more economically and environmentally benign next-generation technology for ethanol production from industrial tail gas.

Paper-Mill Wastes for Bioethanol Production in Relation to Circular Economy Concepts: A Review

This review explores circular economy principles in regard to ethanol production from paper-mill sludge. Environmental sustainability and renewability over fossil fuels make second generation ethanol an attractive energy source in a rapidly growing population and consumption world. Paper sludge (PS), a by-product of the pulp and paper (P&P) industry, can no longer be recycled for paper production and is mainly disposed of in landfills. Therefore, it poses a major environmental challenge. However, it has shown potential as a valuable raw material for ethanol production, along with other pulp and paper products, due to its abundant availability and high cellulosic content. This waste-to-energy (WtE) technology for ethanol production is proposed as an alternative, aligning with circular economy concepts to maximize resource efficiency and minimize waste. This review underlines the circular economy aspects of bioethanol production within paper mill sludge management systems. Circular economy principles applied to ethanol production from PS offer a promising avenue for sustainable biofuel development that not only addresses waste management challenges but also enhances the overall environmental performance of biofuel production. Furthermore, economic benefits are described, highlighting the potential for job creation and community development.

APPLICATION OF ALTERING PRESSURE IMPULSES FOR DELIGNIFICATION OF WHEAT STRAW

Based on the growth of global energy demand, the limitation of fossil energy sources, and the growth of greenhouse gas emissions due to the use of fuels based on them, there is a need for wider use of renewable energy sources in particular biomass. The main purpose of the stage of pretreatment of lignocellulosic raw materials for hydrolysis in the second-generation fuel ethanol production technology is to destroy the heterogeneous matrix, increase the surface area and porosity of the cellulosic material, and release carbohydrates from the lignin bond, thereby improving enzymatic digestibility. The aim of the study is to compare the effect of alternating impulses of pressure and autoclaving on lignin removal during the pretreatment of wheat straw for enzymatic hydrolysis in the technology of fuel ethanol production. It was determined that increasing the alkali concentration from 0.5 to 4 % wt. reduces the lignin content in the sample from 51.0 to 24.5 % of the initial content for autoclaving at 90 °С, at 121 °С the content of lignin decreases from 40.6 to 17.5 %. Processing at a temperature of 90 °С reduces the lignin content from 43.0 to 18.5 %. The minimum lignin content in the sample was 18.5 % of the initial content for autoclaving at 90 °C for 60 min process, at 121 °С the minimum content of lignin in the sample and the amount of released lignin was observed for 60 min and amounted to 17.5 %. Processing leads to the lignin content in the sample up to 17.5 % for 120 min. The minimum content of lignin in the sample for autoclaving was 17.5 % at 121 °С. For processing, the maximum value of removed lignin was 18.5 % at 90 °С. It was determined that the addition of alternating pressure pulses allows, at atmospheric pressure and a temperature lower than 100 °С, to obtain a degree of lignin removal comparable to the degree of lignin removal in an autoclave at a temperature of 121 °С, which is usually the basis for the process of pretreatment of plant raw materials for hydrolysis in the technology of obtaining fuel ethanol. Bibl. 16, Fig. 5.

Enhanced ethanol production using hydrophobic resin detoxified Pine forest litter hydrolysate and integrated fermentation process development supplementing molasses.

Globally escalating ethanol demand necessitates the use of hybrid technologies integrating first- and second-generation biofuel feedstocks for achieving the futuristic targets of gasoline replacement with bioethanol. In present study, an optimized two-step sequential pre-treatment (first dilute alkali, then dilute acid) of Pine forest litter (PFL) was developed. Furthermore, the saccharification of pre-treated PFL was optimized through Response Surface Methodology using Box-Behnken Design, wherein 0.558g/g of reducing sugar was released under the optimized conditions (12.5% w/v of biomass loading, 10 FPU/g of PFL enzyme loading, 0.15% v/v Tween-80 and 48h incubation time). Moreover, during hydrolysate fermentation using Saccharomyces cerevisiae NCIM 3288 strain, 22.51 ± 1.02g/L ethanol was produced. Remarkably, hydrophobic resin (XAD-4) treatment of PFL hydrolysate, significantly removed inhibitors (Furfural, 5-hydroxymethylfurfural and phenolics) and increased ethanol production to 27.38 ± 1.18g/L. Furthermore, during fermentation of molasses supplemented PFL hydrolysate (total initial sugar: 100 ± 3.27g/L), a maximum of 46.02 ± 2.08g/L ethanol was produced with 0.482g/g yield and 1.92g/l/h productivity. These findings indicated that the integration of molasses to lignocellulosic hydrolysate, would be a promising hybrid technology for industrial ethanol production within existing bio-refinery infrastructure.

Bioethanol production from alkali-pretreated rice straw: effects on fermentation yield, structural characterization, and ethanol analysis.

Current ethanol production technology has a dire need for efficient conversion of lignocellulosic biomass to fermentable sugars. The conversion requires pretreatment of the biomass, one of the most expensive steps, and thus it is quite necessary to identify the most cost-effective and high-efficiency conversion method. In this study, rice straw (RS) biomass was pretreated using 4% NaOH alkali, soaked for 4 h, and autoclaved for 30min. The structural and morphological changes were examined using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis in both native and alkali-treated RS. The FTIR analysis revealed that native RS contains a considerable amount of lignin that was removed after the pretreatment process. The XRD pattern of the RS revealed an increasing crystallite size of the pretreated lignocellulosic biomass. The study of SEM clearly showed the distorted structure and surface porosity after the pretreatment process. Enzymatic hydrolysis efficiency was checked by comparing the commercial enzymes and microbial hydrolysis extracted from a fungal isolate. The best-reducing sugar yield obtained was 0.62g/L, achieved at optimized conditions from the commercial enzymes. Fermentation efficiency was checked using the yeast isolate Saccharomyces cerevisiae in both the native and pretreated substrate, and the highest ethanol concentration (21.45%) was achieved using 20% w/v biomass loading, enzyme loading (2:1:1), and fermentation for a week at 30°C and pH 4.5. This concentration was higher than that of the untreated RS (3.67%). The ethanol thus produced was further checked for analysis by the 1H and 13C nuclear magnetic resonance (NMR) methods.

Biomethane Production from Sugarcane Vinasse in a Circular Economy: Developments and Innovations

Sugarcane ethanol production generates about 360 billion liters of vinasse, a liquid effluent with an average chemical oxygen demand of 46,000 mg/L. Vinasse still contains about 11% of the original energy from sugarcane juice, but this chemical energy is diluted. This residue, usually discarded or applied in fertigation, is a suitable substrate for anaerobic digestion (AD). Although the technology is not yet widespread—only 3% of bioethanol plants used it in Brazil in the past, most discontinuing the process—the research continues. With a biomethane potential ranging from 215 to 324 L of methane produced by kilogram of organic matter in vinasse, AD could improve the energy output of sugarcane biorefineries. At the same time, the residual digestate could still be used as an agricultural amendment or for microalgal production for further stream valorization. This review presents the current technology for ethanol production from sugarcane and describes the state of the art in vinasse AD, including technological trends, through a recent patent evaluation. It also appraises the integration of vinasse AD in an ideal sugarcane biorefinery approach. It finally discusses bottlenecks and presents possible directions for technology development and widespread adoption of this simple yet powerful approach for bioresource recovery.

High-temperature ethanol fermentation from pineapple waste hydrolysate and gene expression analysis of thermotolerant yeast Saccharomyces cerevisiae

High-temperature ethanol fermentation by thermotolerant yeast is considered a promising technology for ethanol production, especially in tropical and subtropical regions. In this study, optimization conditions for high-temperature ethanol fermentation of pineapple waste hydrolysate (PWH) using a newly isolated thermotolerant yeast, Saccharomyces cerevisiae HG1.1, and the expression of genes during ethanol fermentation at 40 °C were carried out. Three independent variables, including cell concentration, pH, and yeast extract, positively affected ethanol production from PWH at 40 °C. The optimum levels of these significant factors evaluated using response surface methodology (RSM) based on central composite design (CCD) were a cell concentration of 8.0 × 107 cells/mL, a pH of 5.5, and a yeast extract concentration of 4.95 g/L, yielding a maximum ethanol concentration of 36.85 g/L and productivity of 3.07 g/L. Gene expression analysis during high-temperature ethanol fermentation using RT–qPCR revealed that the acquisition of thermotolerance ability and ethanol fermentation efficiency of S. cerevisiae HG1.1 are associated with genes responsible for growth and ethanol stress, oxidative stress, acetic acid stress, DNA repair, the pyruvate-to-tricarboxylic acid (TCA) pathway, and the pyruvate-to-ethanol pathway.

Fungal amylases applied to the sweet potato starch for bioethanol production

Bioethanol is a sustainable energy source to help reducing the emission of pollutants into the global environment. In order to cope with that, the ethanol production technologies and use of efficient and low-cost substrates are developed. The objective of this research was to evaluate fungal amylases in sweet potato starch for bioethanol production by Saccharomyces cerevisiae in the laboratory. Endomelanconiopsis endophytica (1.40 U/mL), Neopestalotiopsis cubana (1.67 U/mL) and Fusarium pseudocircinatum (1.11 U/mL) with high enzymatic activities were selected and their amylases were tested for activity on sweet potato starch for bioethanol production. Simultaneous saccharification and fermentation was performed at 30° C and pH = 5.0. 17.3 - 88.1 (%) of bioethanol that was produced and compared to the expected theoretical yield. Therefore, amylases from these fungi simultaneously inserted on sweet potato starch and S. cerevisiae are potentially useful for bioethanol production.

Is anaerobic co-digestion the missing link to integrate sugarcane biorefinery?

This study evaluated the potential of energy generation from anaerobic co-digestion (AcD) of vinasse and hemicelluloses hydrolysate within the context of an integrated 1G-2G sugarcane biorefinery as a mean to ensure its technical, economic and environmental feasibility. Environmental impact indexes for 2G ethanol and biogas production process, such as carbon footprint, which varied from 12.3 to 50.02 g CO2/MJ and reduction of greenhouse gas (GHG) emissions (from 42.7 to 85.9%), were obtained in all scenarios. Economic indicators showed the unviability of 1G-2G sugarcane mill integration adopting AcD of wastes, considering technologies for 2G ethanol production in view of their high capital and operational costs (pretreatment). However, by fixing the experimental methane yield at 0.245 Nm3 kg COD−1r which has been obtained for two-stage anaerobic systems and by considering the use of 50% of bagasse surplus for biogas production, it was possible to achieve internal rate of return (IRR), return on investment (ROI) and payback period of 21.8%, 59.50% and 10.55 years respectively. Moreover, when experimental methane yield is increased in 10% in such scenario, it was possible to achieve internal rate of return (IRR), return on investment (ROI) and payback period of 26%,89.05% and 5.36 years, respectively.

CO2-to-Fuel – Business and Institutional Aspects of Implementation Dynamics

Abstract Valorization of CO2 captured from industrial processes is an important task for reaching climate and energy targets. The presented study addresses the use of CO2 for the production of ethanol, which can be used as a transport fuel. Hydrogen, produced by renewable energy technologies, is combined with CO2 to produce the synthetic fuel, thus making this approach attractive from a climate perspective. Aim of the study was to simulate the dynamics of the development of CO2-to-fuel solution, taking Latvia as the case. System dynamics modelling was used as the method for analysis. The model reflects several important feedbacks, such as relation between the captured CO2 emissions and the share of avoided CO2 emissions in transport due to fuel substitution, as well as investment in new production capacity of the ethanol. Use of avoided CO2 emission costs for funding of research and development (R&D) of the technology and direct subsidies for ethanol production is the analysed institutional aspect. The results show that if 15 % of the industrial CO2 emissions are used for ethanol production then circa 12 % of the transport CO2 emissions can be avoided. The share of avoided transport CO2 emissions are the most sensitive to unit costs of hydrogen production.

The water consumption of sugarcane bagasse post-washing after protic ionic liquid pretreatment and its impact on 2G ethanol production

Despite the water consumption of the first-generation ethanol (1G) production from sugarcane being widely studied, there are only a few experimental studies on water consumption — especially in the pulp washing — in second generation (2G) ethanol production. A quantitative evaluation of water wash consumption in the pretreatment with the protic ionic liquid (PIL) monoethanolammonium acetate [MEA][OAc] has shown that a water consumption between 600−1,000 wt% for two temperatures, 25 and 80 °C, decreased overall enzyme performance in saccharification compared to the full wash sample. The best condition in terms of high yield and low water consumption was found to be 800 wt%/80 °C, with up to 83 and 61.8 % of glucose and xylose yields against 97.9 and 85 % for the full wash sample. However, despite the full wash still presenting a superior ethanol yield, 87.4 %, the best condition with limited amount of water, 800 wt%/80 °C, also had a high ethanol yield of 86.1 %. Mass balance calculations confirmed that optimized [MEA][OAc] pretreatment with 800 wt%/80 °C and full wash conditions provided the highest ethanol yield per ton of biomass amongst several types of PIL and non-PIL pretreatments, 299 and 379 L 2G ethanol per ton of biomass, with an estimated water consumption of 56 and 647 ton, paving the way for an effective and more water-sustainable pretreatment technology for 2G ethanol production.

The synergistic actions of hydrolytic genes reveal the mechanism of Trichoderma harzianum for cellulose degradation

Bioprospecting genes and proteins related to plant biomass degradation is an attractive approach for the identification of target genes for biotechnological purposes, especially those with potential applications in the biorefinery industry that can enhance second-generation ethanol production technology. Trichoderma harzianum is a potential candidate for cellulolytic enzyme prospection and production. Herein, the enzymatic activities, transcriptome, exoproteome, and coexpression networks of the T. harzianum strain CBMAI-0179 were examined under biomass degradation conditions. We identified differentially expressed genes (DEGs) and carbohydrate-active enzyme (CAZyme) genes related to plant biomass degradation and compared them with those of strains from congeneric species (T. harzianum IOC-3844 and T. atroviride CBMAI-0020). T. harzianum CBMAI-0179 harbors strain- and treatment-specific CAZyme genes and transcription factors. We detected important proteins related to biomass degradation, including β-glucosidases, endoglucanases, cellobiohydrolases, lytic polysaccharide monooxygenases, endo-1,4-β-xylanases and β-mannanases. Based on coexpression networks, an enriched cluster with degradative enzymes was described, and the subnetwork of CAZymes revealed strong correlations among important secreted proteins and differentially expressed CAZyme genes. Our results provide valuable information for future studies on the genetic regulation of plant cell wall-degrading enzymes. This knowledge can be exploited for the improvement of enzymatic reactions in biomass degradation for bioethanol production.

Integration of First- and Second-generation Bioethanol Production from Beet molasses and Distillery Stillage After Dilute Sulfuric Acid Pretreatment

The possibility of using waste distillery stillage (first-generation technology) after dilute acid pretreatment, as a medium for the preparation of beet molasses mash, for ethanol production according to the simultaneous saccharification and fermentation (SSF) technology, was assessed. The combination of lignocellulosic hydrolysates made from acid-pretreated stillage with sugar-rich beet molasses is an effective way of utilizing the first-generation ethanol production by-products in the second-generation ethanol production technology. It was demonstrated that the final ethanol concentration could be as high as 90 g/L. The process yield was over 94% of the theoretical yield when the molasses was diluted using acid-pretreated maize distillery stillage. An attempt to increase the pool of fermentable sugars by using cellulases to hydrolyze cellulose failed due to product inhibition in the fermentation medium with a high glucose concentration. A more than threefold increase in the concentration of ethyl acetate (even up to 924.4±11.8 mg/L) was observed in the distillates obtained from the media incubated with cellulases. The use of beet molasses combined with the hydrolysate of pretreated distillery stillage also changed the concentration of other volatile by-products. An increase in the concentration of aldehydes (mainly acetaldehyde to a concentration of above 1500 mg/L), methanol, 1-propanol, and 1-butanol was observed, while the concentration of higher alcohols (isobutanol, 2-methyl-1-butanol, 3-methyl-1-butanol) decreased. Interestingly, the use of cellulases in fermentation media from molasses and stillage hydrolysates resulted in an average fourfold increase in the concentration of this ester to a maximum level of 924.4±11.8 mg/L. Hydrolysates made from acid-pretreated distillery stillage, combined with sugar-rich beet molasses to boost the efficiency of the conversion process, can be successfully used in the production of second-generation fuel ethanol. However, further optimization of the cellulose enzymatic hydrolysis process is required for efficient use of the raw material.

Bioethanol Production from Yam (Dioscorea Rotundata) Using Simultaneous Saccharification and Fermentation (SSF)

Yam is a starchy tuber mainly used in food preparation but with high potential applications in other fields such as pharmaceutical and bioplastic production. Colombia is among the top twelve yam producing countries worldwide and ranked first in terms of yield of tons per hectare planted. Yam production has specifically been concentrated in the Caribbean region, which is why this tuber is very little known in the inland regions. In this study, we evaluated Simultaneous Saccharification and Fermentation (SSF) for bioethanol production from yam (Dioscorea rotundata) using Saccharomyces bayanus. Ethanol production technologies involve the fermentation and hydrolysis of consumable raw materials (i.e., sugar cane and corn) which are quite mature around the world. For this reason, the process under analysis combined three phases: 60 min of gelatinization, enzymatic hydrolysis (divided into 40 min of liquefaction with α-amylase and 20 min of saccharification with glucoamylase), and 27 h of fermentation with no enzyme recovery. We used different yam concentrations (10, 12.5, 15, and 18 % w/w) in a wet basis. SSF was monitored along time, and total reducing sugars and ethanol concentration were quantified. The hydrolysis yield, was calculated based on the theoretical starch available in the tuber, was 90 % of starch mass for samples with a yam concentration of 10 and 15 % w/w. Regarding ethanol, the best result (a productivity of 0.19 g/Lh-1) was obtained with the sample with a yam concentration of 10 % w/w. Therefore, yam is a starchy material suitable to produce bioethanol via SSF.

Proteomics Answers Which Yeast Genes Are Specific for Baking, Brewing, and Ethanol Production.

Yeast strains are convenient models for studying domestication processes. The ability of yeast to ferment carbon sources from various substrates and to produce ethanol and carbon dioxide is the core of brewing, winemaking, and ethanol production technologies. The present study reveals the differences among yeast strains used in various industries. To understand this, we performed a proteomic study of industrial Saccharomyces cerevisiae strains followed by a comparative analysis of available yeast genetic data. Individual protein expression levels in domesticated strains from different industries indicated modulation resulting from response to technological environments. The innovative nature of this research was the discovery of genes overexpressed in yeast strains adapted to brewing, baking, and ethanol production, typical genes for specific domestication were found. We discovered a gene set typical for brewer’s yeast strains. Baker’s yeast had a specific gene adapted to osmotic stress. Toxic stress was typical for yeast used for ethanol production. The data obtained can be applied for targeted improvement of industrial strains.

Recycling of Black Liquor for Treating Sugarcane Bagasse at Low Temperature to Attain High Ethanol Production without Washing Step

Alkaline pretreatment has been commonly used for bioconversion of lignocellulose into fuel ethanol due to its gentle condition. However, the large quantity of water consumption and wastewater generation from the pretreatment and washing steps have been two bottleneck problems for the practical application of alkaline pretreatment. In order to save water consumption and reduce wastewater generation, black liquor (BL) generated in the sodium hydroxide (NaOH) pretreatment process was recycled for pretreating sugarcane bagasse (SCB), and the BL-NaOH-treated SCB without being washed was directly enzymatically hydrolyzed and fermented. After 120-h fed-batch enzymatic hydrolysis with the addition of 20 FPU cellulase/g cellulose and 2.51 μL Tween80/mL hydrolytic slurry, the maximum glucose concentration and enzymatic hydrolysis efficiency achieved 99.95 g/L and 71.02%, respectively. After 36-h fermentation with the domesticated Saccharomyces cerevisiae, the ethanol production reached 44.53 g/L, which amounted to 87.35% of theoretical ethanol yield. Compared with other water-saving and wastewater-reducing alkaline pretreatments, this technology saved more than 20% water consumption and reduced over 20% wastewater discharge. It provides a promising applied technology for cellulosic ethanol production.

Expansion and scale up of technology for ethanol production based on the concept of biorefinery

AbstractThe rapid growth of industries and large number of population are considered to be the major two factors that contribute to the crisis of global energy. Biofuels are considered to be the best replacement of the energy produced from the nonrenewable fossil fuels. The use of mature technologies depicts a sear need of biomasses that it causes a competition with the food chain in case of the first generation of Bioethanol. This disadvantage was overcome by the second generation bioethanol where lignocellulosic biomass is the raw material. Algal biomass from marine environment has also gained a lot of importance in third and fourth generation of raw material for biofuel production. The main challenge arrived when scaling up became the biggest problem in the process of bioethanol production. This review mainly aims to focus on the challenges faced in the commercialization of the biofuels. Many scientists are working majorly on economic processes so as to commercialize the biofuel production techniques. Some energy and cost effective distillation process has been described in this review article, which can help in the scaling up the process to an industrial level.Practical ApplicationsThis review mainly aims to focus on the basic overview of the bioethanol production and the challenges faced in the commercialization of the biofuels. Many scientists around the globe are working majorly on economic processes so as to commercialize the biofuel production techniques. The review compiles the evolution of one generation biofuels from another by overcoming the disadvantages of the previous generation. This will help the young researchers to have a complete idea about significance of bioethanol production. In the present times, there are many less pollution causing and renewable natural resources that can produce bioethanol in the laboratory scale effectively. The main challenge is to produce bioethanol in large scale. Though this area for scale up technologies of the ethanol production is less explored, but there is immense scope of development and modification.

Formulating a fully converged biorefining chain with zero wastewater generation by recycling stillage liquid to dry acid pretreatment operation

Huge wastewater generation is the major challenge of biorefinery technology for production of cellulosic ethanol. This study designed and verified a method for completely recycling of wastewater stream (the stillage liquid from the beer column) in cellulosic ethanol production by dry biorefining processing. When the stillage liquid was directly recycled to dry acid pretreatment operation, ethanol production gradually reduced after two recycles primarily because the inorganic compounds accumulated by around 139%. To ultimately solve this technical barrier, the stillage liquid was evaporated and condensed into distillated water, then recycled to the pretreatment for complete dry biorefining process. This strategy supported a stable cellulosic ethanol production, and the overall mass and heat balance confirmed that only 65% of the lignin residue consumption was used for wastewater evaporation with 35% surplus for electricity generation. This study provided a fully converged biorefining process with a closed-loop wastewater recycling.

Modelling the trash blanket effect on sugarcane growth and water use

The traditional practice of burning at the pre-harvesting of sugarcane has being phased-out in Brazil, resulting in the maintenance of a crop s residue layer on soil surface, namely the Green Cane Trash Blanket (GCTB). New technologies for electricity and second-generation ethanol (2G) production from crop residues have raised the question on what would be the optimum amount of crop residue left on the field to keep the agronomic and environmental benefits of GCTB. To support informed decision making on sugarcane trash management, we updated, evaluated and applied a new version of the SAMUCA model to simulate the sugarcane growth and water use under the GCTB effect. The updated model was calibrated and parameterized for bare soil and GCTB conditions and evaluated across different Brazilian regions. Thirty-year simulations were then conducted with the updated model to quantify the effects of GCTB on sugarcane growth and water use where sugarcane is traditionally grown in Brazil. The updated version of SAMUCA model showed equal or superior performance when compared with widely-used process-based models for sugarcane. Based on our 30-year simulations, the GCTB exhibited a high probability to promote a beneficial effect on sugarcane yields in dry climates (>90%), with the potential for increasing, on average, 14 ton ha−1 of fresh cane yield in Petrolina, Brazil. Although the beneficial effect on yields were not significant in humid regions, the maintenance of 12 ton ha−1 of GCTB was associated with a high probability (>87%) in reducing the water use of sugarcane cropping system by 89 mm, on average, potentially reducing irrigation demand in the early stages of crop development while protecting crop production under dry spell events. The new version of SAMUCA model offers as a tool for decision making on mulch management in sugarcane plantations.

Bio-ethanol (2nd Generation Ethanol): A Solution to Ever Polluting Gasoline to Climate in India

Environmentally sustainable energy sources are called for due to contemporaneous development in industries along with the rapid pace of urbanization. Ethanol produced from biomass can be deliberated as a clean and safest liquid fuel and an alternative to fossil fuels as they have provided unique environmental, strategic economic benefits. For the past decade, it has been noticed that there is an increasing trend found in bio ethanol production which has created a stimulus to go for advancement in bio ethanol production technologies. Several feed stocks have been used for the bio ethanol production but the second generation bio ethanol has concentrated on the lignocellulosic biomass. Plenteous lignocellulosic biomass in the world can be tapped for ethanol production, but it will require significant advances in the ethanol production process from lignocellulosic because of some technical and economic hurdles found in commercial scale. This review will encompass the current status of bio ethanol production in terms of their economic and environmental viability along with some research gaps as well as policy implications for the same.