Maximum Bioethanol Yield Research Articles

Potency of Some Savanna Herbaceous Weeds in the Production of Bioethanol Using Zymomonas mobilis and Saccharomyces cerevisiae

The uncertainty of the fossil fuel and global climate changes has invariably led to renewable energy demand. Thus, necessitating increasing biotechnological research efforts. Accordingly, the current work was designed to investigate the potency of some savanna herbaceous weeds in the production of bioethanol using Zymomonas mobilis and Saccharomyces cerevisiae. The biodiversity study and the proximate analysis of weed samples growing on Bayero University Kano old Campus, Nigeria were carried out. The substrates were pretreated with 2% of 0.233M sulfuric acid solution and hydrolysed using Aspergillus niger. The reducing sugars were estimated using the dinitrosalicylic acid method. Fermentation was carried out using local strains of Zymomonas mobilis and Saccharomyces cerevisiae isolated from fermented Zobo drink and palm wine under anaerobic conditions. The absorbance of the produced bioethanol was measured and compared with the known standard ethanol curve using Techme I Uv-vis spectrophotometry at 600nm. The dominant weeds include; Cynodon dactylon (30%), Heteropogon contortus (20%) and panicum virgatum (13.45%). The carbohydrate contents as hemicellulose ranged from (35.44 - 27.68%), cellulose (39.80 - 29.20%) and lignin contents (4.32 - 2.14%). The reducing sugar ranged from (24.67±0.01 - 94.79±0.01 mg/g) in all the substrates used. Maximum bioethanol yield was obtained with Cynodon dactylon (48.09±0.07ml/g) in fermentation with a cocktail of the microorganisms whereas, the minimum yield was observed with Heteropogon contortus (15.08±0.01 mL/g). Zymomonas mobilis had the maximum bioethanol yield (29.20±0.01ml/g) than Saccharomyces cerevisiae with (20.10±0.01 mL/g) bioethanol (p>0.05). The findings reveal the lignocellulosic weeds used in this study are good substrates which can be exploited in bioethanol production.

Coupled pretreatment of rice straw with dairy wastewater and ultrasonication for biofuel production using mixed microbial source

This study describes the effect of ultrasonic pretreatment on bioethanol, bio-methanol, methane and volatile fatty acids production from dairy wastewater pretreated rice straw. The study was carried out in eight batch reactors with inoculums derived from cow dung and soil separately (four for each cow dung and soil). These reactors were fed with dairy wastewater pretreated rice straw followed by ultrasonic bath pretreatment for 5, 10 and 15 min for three separate reactors and the fourth reactor was set up without pretreatment. Maximum methane yields were 303.2 L/kgRS (for untreated reactor) and 151.62 L/kgRS (for the reactor with 15 min ultrasonication) with soil and cow dung, respectively. Maximum bioethanol yield was 970.2 mg/LReactor volume and 779.2 mg/LReactor volume with cow dung (for reactors with 15 min ultrasonication) and soil (for 5 min ultrasonic pretreatment), respectively. Acetic acid was the major acid produced (98–99 % of total VFAs) among all the VFAs.

Valorisation of chewing gum production waste in bioethanol production: a response surface methodology study

ABSTRACT Interest in fast-moving consumer goods (FMCG) is constantly growing all over the world. Chewing gum, which is in the group of pleasant and entertaining snacks preferred by people of all ages, especially children and young people, is one of the most consumed products in the food sector. Due to its remarkable production and the major components, chewing gum waste has the potential as an alternative sugar source for bioethanol production. To evaluate bioethanol production from chewing gum wastes, the sugar was first extracted, and directly fermented into ethanol under different conditions. Saccharomyces cerevisiae (fresh and dry) and Saccharomyces bayanus were used as the yeast. To determine the optimal fermentation medium, the response surface methodology (RSM) study was employed and the fermentation medium variables were tested such as agar, pepton and glucose (APG medium) concentrations. The APG medium in which the maximum bioethanol yield obtained was determined as 5 g/L agar, 10 g/L peptone and 5 g/L glucose. The highest ethanol yield under optimal APG medium was obtained as 9.1-4 g ethanol/L sugar after 72 h by using Saccharomyces cerevisiae (fresh). The obtained results showed that chewing gum wastes can be utilised a potential source for the bioethanol production.

Integrated Approach for Bioethanol and Paper Production using Populus deltoides Wood Biomass: An Experimental Study

Lignocellulosic materials contain two major sugar macromolecules, cellulose and hemicellulose, and polyphenolic lignin. During pulping, lignin and hemicellulose are broken down into smaller molecules such as organic acids, and removed in the black liquor, leaving cellulose fibers for papermaking. Lignocellulose consists of approximately 28–35% hemicelluloses, which are lost during the pulping process in black liquor and are an important source of sugars that can be used to produce bioethanol as a liquid fuel. The hemicellulosic sugars from the Populus deltoides (poplar) lignocellulosic biomass were partially extracted keeping in mind that it does not affect the properties of paper beyond acceptable limits, further converting these extracted sugars by fermentation to bioethanol, followed by pulping the residual biomass and papermaking and determining pulping and papermaking properties. With the increasing demand for lignocellulosic biomass by various industries, an integrated biorefinery approach for maximum utilization of its chemical components with minimum degradation is necessary in the future. The maximum bioethanol yield was found to be 3.58 g/L. On manufactured paper sheets, the mechanical properties tensile index and tear index of pre-extracted biomass were observed as 19.23 Nm/g and 3.5 mNm2/g and slightly lower against the control 21.34 Nm/g and 4.0 mNm2/g. The main objective of the present study is to recover reducing sugars before the pulping process for bioethanol production and to further utilize the remaining residue for papermaking without disturbing its fiber integrity.

Experimental investigation on effect of season on the production of bioethanol from wheat-stalk (WS) using simultaneous saccharification and fermentation (SSF) method

Global dependency on conventional fuel, its limited stock, and their adverse effects on the environment have driven researchers into alternative fuel. Wheat-stalk (WS), which is a residue of the harvested wheat crop, is considered a potential feedstock for bioethanol production as an alternative fuel due to its high cellulose and hemicellulose content and abundant availability. The objective of this work is to optimize the environment condition for fermentation in the different seasons to get the maximum bioethanol production yield from wheat-stalk straw (WSS) by using minimal laboratory resources. In this study, field collected WS was taken for physical treatment to get size less than 1 mm. Steam explosion pretreatment of WSS was performed to increase its accessible surface area and to reduce degree of polymerization. Next, to remove lignin, it was pretreated with alkali (1 M NaOH) with a solid-loading of 1:15 (w/v) at pH 10. After that, an acidic pretreatment was performed with 0.1 N diluted H2SO4 at pH 4.8 to increase anaerobic digestibility and for quicker hydrolysis. The pretreated WSS slurry was further enzymatically hydrolysed for 48 h to have monomeric sugar from cellulose and hemicellulose by adding cocktail of three enzymes amylase, cellulase, and hemicellulase with amount of 0.1% w/v of each. After that simultaneous saccharification and fermentation (SSF) were performed to convert monomeric sugar into bioethanol in the presence of microbial yeast media containing yeast (1% w/v), and peptone (2% w/v) under anaerobic conditions at pH 5.0. It has been found that the minimum time required during SSF for bioethanol production is different for different seasons. In addition, the fermentation period is shorter in monsoon as compared to spring and summer. As the fermentation period increases, the production of bioethanol yield increases up to a certain limit. The maximum bioethanol yields from the WSS were obtained as 0.183, 0.19, and 0.21 ml/g of dry WSS biomass in the spring, summer, and monsoon seasons for the fermentation period of 15, 9, and 11 days respectively. Consequently, it has been found that the enhancement in maximum bioethanol yield in the monsoon season is 8.42% and 12.57% as compared to the summer and spring seasons, respectively.

Bioconversion of Sargassum wightii to ethanol via consolidated bioprocessing using Lachnoclostridium phytofermentans KSM 1203

Contemporary studies suggest that macroalgal biomass is an attractive and alternate source for ethanol production to replace fossil fuel. Sargassum wightii, a brown macroalgae, rich in cellulose is suitable for bioethanol production. This investigation focused on the pretreatment, enzyme saccharification and fermentation for bioethanol production through consolidated bioprocessing (CBP) using Lachnoclostridium phytofermentans KSM 1203 isolate. The cellulose extraction from S. wightii biomass and essential medium components for L. phytofermentans KSM 1203 were optimized using Response Surface Methodology. The alkali pretreatment on S. wightii biomass removed lignin and hemicelluloses with the cellulose recovery of 82.35%. The sodium hyphochlorite treatment removes other contaminants, results the semi crystalline to amorphous cellulose structure. The optimized medium components for L. phytofermentans KSM 1203 was found to be pre-treated biomass 3.92 g/L, peptone 2.21 g/L, dipotassium hydrogen phosphate 1.84 g/L and sodium chloride 2.03 g/L and for the growth and co-production of cellulase activity and ethanol productivity. The maximum bioethanol yield was obtained under the optimal conditions to be 13.75 ± 0.687 g/L for L. phytofermentans KSM 1203 from pre-treated S. wightii biomass. Hence, this investigation suggests that wild type L. phytofermentans KSM 1203 strain could be exploited for the utilization of cellulose for production ethanol in a single-step CBP procedure.

Second Generation Bioethanol Production from Soybean Hulls Pretreated with Imidazole as a New Solvent

Soybean hulls (SH) are the main industrial waste from soybean processing, representing 5–8% of the whole grain. Imidazole was employed for the hydrothermal pretreatment of SH and further bioethanol production. Different pretreatment temperatures (120 and 180 °C) and times (1 and 3 h) were tested. Lignin removal and glucose yield were significantly influenced by temperature. After 48 h of enzymatic hydrolysis of imidazole-treated SH (120 °C, 1 h), 32.7 g/L of glucose and 9.4 g/L of xylose were obtained. A maximum bioethanol yield of 78.9% was reached after 12 h of fermentation by Saccharomyces cerevisiae using SH enzymatic hydrolysate. Imidazole appears to be a potential alternative to pretreat lignocellulosic wastes such as SH for the production of second-generation biofuels and other biomolecules.

Commercial Seaweed Liquid Extract as Strawberry Biostimulants and Bioethanol Production.

Seaweeds are increasingly intriguing as a sustainable source of bioactive compounds. They have applications in agriculture, fuels, feed, and food products. To become a cost-competitive product with zero waste, a biorefinery approach is applied, where several products are valorized at the same time. True-Algae-Max (TAM®) has been investigated for its ability to improve the yield and nutritional facts of a strawberry plant. Three concentrations of TAM (0, 50, and 100%) were examined by foliar spray in 2017 with 50% NPK chemical fertilizer. Results indicated that growth, yield, chlorophyll, and potassium content were significantly improved by TAM treatments. TAM50 % resulted in maximum root length, leaf area, plant fresh weight, fruit weight, and yield with an increase ranging from 10 to 110% compared to control. Compared to the NPK control, strawberries grown with TAM50% improved total soluble solids (TSS) from 7.58 to 10.12% and anthocyanin from 23.08 to 29.42 mg CGE 100 g-1. Noteworthily, this reduced total sugar, and total phenolics were boosted by TAM applications, while non-reducing sugar was reduced compared to control. On the other hand, whole seaweed biomass and TAM residuals were used for bioethanol production by acid scarification. The maximum bioethanol yield was observed in residual biomass (0.34 g g-1 dw), while the whole seaweed biomass showed only 0.20 g g-1 dw. These results proved the biorefinery concept of using seaweed extract as a biostimulator and bioethanol production.

Determination of optimum conditions for maximum bioethanol yield from the Nigerian sweet potato (Ipomoea Batatas (L.) Lam)

Bioethanol is an important biofuel produced from biomass and is generally regarded as the future of fuels. This research was carried out for the main purpose of determining the optimum process conditions required for maximum bioethanol yield from the pulp of local sweet potato. The variety of potato used in this research is the Nigerian sweet potato (Ipomoea Batatas (L.) Lam) containing high amount of starch and the experiment was carried out with the use of Baker’s Yeast (Saccharomyces cerevisae) as the biocatalyst. In this study, the effect of acid concentration for hydrolysis, pH and fermentation period was examined. The sweet potato pulp was hydrolyzed using dilute sulphuric acid solutions of 0.5M, 1.5M and 2.5M and heated for 30 minutes at 100 ℃ yielding 0.9% (v/v) reducing sugar for fermentation. The hydrolysates were then subjected to fermentation at different pH values for different fermentation periods of 2, 3.5 and 5 days respectively. The pH values ranged from 4.5 to 6.5, an increment of 1.0 was used during the examination of pH with 1.0 M sodium hydroxide solution (NaOH) used for adjustment. The rate of bioethanol production was seen to increase as the pH and fermentation periods increased with the exception of the fermenting cultures of pH of 6.5. The maximum bioethanol yield of 13.40 ml, equivalent to 3.350% (v/v), was gotten from the hydrolysate obtained using the dilute acid of concentration 0.5M and left to ferment for 5 days at a pH of 5.5.

Bioethanol Production from Rice Husk through SHCF and SSCF Processing Strategies

In many developing countries, there is great quest for achieving sustainable energy from the conversion of the huge biomass of organic wastes into useful biofuels such as bioethanol. Bioethanol is a renewable clean-liquid biofuel produced by fermentation of sugars or converted starch or cellulose from plant based feedstocks. It is conventionally produced from sugar and starch containing feedstocks. However, these feedstocks are unable to meet the global demand of bioethanol production due to their primary food value and legal pursuits against the legitimacy of their schemes. This study investigated and improved on the feasibility of producing bioethanol from rice husk agrowaste generated from rice production. It was first subjected to different physico-chemical pretreatments in order to optimize the hydrolysate sugar yield and identify the most effective process. It was further hydrolyzed by cellulase enzymes from Trichoderma ressei micro-organism isolated from the soil. Separate hydrolysis and co-fermentation (SHCF) and simultaneous saccharification and co-fermentation (SSCF) strategies/methods were adopted using both hydrometer and Pycnometer measurements. The fermentation results revealed that the maximum bioethanol yield through SHCF and SSCF strategies were 4.64 and 6.45 (% w/v dry biomass) respectively. SSCF strategy was more effective as it gave better bioethanol yield and was less time consuming. This study also shows that rice husk agro-waste of no or little commercial value can be utilized in the production of good quality bioethanol with implications for improved waste management, income and efficient energy generation.

Bioethanol Production From Rice Husk Through Shcf And Sscf Processing Strategies

In many developing countries, there is great quest for achieving sustainable energy from the conversion of the huge biomass of organic wastes into useful biofuels such as bioethanol. Bioethanol is a renewable clean-liquid biofuel produced by fermentation of sugars or converted starch or cellulose from plant based feedstocks. It is conventionally produced from sugar and starch containing feedstocks. However, these feedstocks are unable to meet the global demand of bioethanol production due to their primary food value and legal pursuits against the legitimacy of their schemes. This study investigated and improved on the feasibility of producing bioethanol from rice husk agro-waste generated from rice production. It was first subjected to different physico-chemical pretreatments in order to optimize the hydrolysate sugar yield and identify the most effective process. It was further hydrolyzed by cellulase enzymes from Trichoderma ressei micro-organism isolated from the soil. Separate hydrolysis and co-fermentation (SHCF) and simultaneous saccharification and co-fermentation (SSCF) strategies/methods were adopted using both hydrometer and Pycnometer measurements. The fermentation results revealed that the maximum bioethanol yield through SHCF and SSCF strategies were 4.64 and 6.45 (% w/v dry biomass) respectively. SSCF strategy was more effective as it gave better bioethanol yield and was less time consuming. This study also shows that rice husk agro-waste of no or little commercial value can be utilized in the production of good quality bioethanol with implications for improved waste management, income and efficient energy generation.

Integrating mild chemical pretreatments with endogenous protein supplement for complete biomass saccharification to maximize bioethanol production by enhancing cellulases adsorption in novel bioenergy Amaranthus

Amaranthus is a fast-growing perennial plant containing large amounts of extractable green proteins and lignocellulose residues. However, it remains to explore optimal Amaranthus biomass process technology for biofuel production. In this study, we examined that mild alkali and acid pretreatments (1% NaOH, 2% H2SO4) were sufficient for near-complete biomass enzymatic saccharification, while 8% Amaranthus endogenous proteins were supplemented into the enzymatic hydrolyses. By performing classic yeast fermentation with all carbon sources from directly-extractable sugars and starch and lignocellulose enzymatic hydrolysis, this work achieved the bioethanol yield up to 23.5% (% dry matter). Notably, with respect to extremely high yield of Amaranthus straw, the maximum bioethanol yield was estimated at 14.46 t/ha/year, which was much higher than those of other major bioenergy crops as previously reported. Furthermore, this work proposed a hypothetic model to elucidate how the complete biomass saccharification was achieved to maximize bioethanol production at large scale, based on the effective wall polymer extraction and distinct lignocellulose feature modification for remarkably enhanced biomass porosity and cellulases adsorption. Hence, this work has demonstrated that Amaranthus could be applied as a novel and leading bioenergy crop, providing a powerful strategy for optimal biomass processing towards high bioethanol production.

Integrated genetic and chemical modification with rice straw for maximum bioethanol production

Crop straw provides huge lignocellulose residues that are transformable for bioethanol production and biochemicals. However, lignocellulose recalcitrance fundamentally causes a costly biomass process that is unapplicable for bioethanol conversion at industrial level with potential waste release. Here, this study selected the transgenic rice (Oryza sativa L.) lines that overexpressed AtCesA6, a typical gene involved in cellulose biosynthesis of primary cell walls in Arabidopsis (Arabidopsis thaliana L Heynh.). This work then examined significantly improved lignocellulose substrates along with much soluble sugars deposition in the transgenic rice straws. By performing green-style pretreatments with mature rice straws using two recyclable and relatively low-cost alkali chemicals (NH3·H2O, CaO) and liquid hot water, this work determined almost complete enzymatic saccharification in the transgenic rice lines. Notably, under two optimal alkali pretreatments, the transgenic rice samples could achieve either bioethanol yields of more than 20 % (% dry matter) or bioethanol concentrations at 18.3 g/L and 19.1 g/L from one-pot relatively high solid loading saccharification, being much higher than those of wild type (Nipponbare). Furthermore, this study examined how the lignocellulose recalcitrance was significantly reduced for remarkably raised enzymatic saccharification in the transgenic rice straws. It also explicated that the maximum bioethanol yield obtained in the transgenic straws should mainly be subjective to near-complete enzymatic saccharification and much directly-fermentable soluble sugars accumulation. Therefore, this study has provided a novel strategy for high bioethanol production by integrating genetically-improved lignocellulose substrates with optimal one-pot-process technology in bioenergy crops.

Modified lignocellulose and rich starch for complete saccharification to maximize bioethanol in distinct polyploidy potato straw

Potato is a major food crop with enormous biomass straw, but lignocellulose recalcitrance causes a costly bioethanol conversion. Here, we selected the cytochimera (Cyt) potato samples showing significantly-modified lignocellulose and much increased soluble sugars and starch by 2–4 folds in mature straws. Under two pretreatments (8 min liquid hot water; 5% CaO) at minimized conditions, the potato Cyt straw showed complete enzymatic saccharification. Further performing yeast fermentation with all hexoses released from soluble sugars, starch and lignocellulose in the Cyt straw, this study achieved a maximum bioethanol yield of 24 % (% dry matter), being higher than those of other bioenergy crops as previously reported. Hence, this study has proposed a novel mechanism model on the reduction of major lignocellulose recalcitrance and regulation of carbon assimilation to achieve cost-effective bioethanol production under optimal pretreatments. This work also provides a sustainable strategy for utilization of potato straws with minimum waste release.

Integrating Mild Chemical Pretreatments with Endogenous Protein Supplement for Complete Biomass Saccharification to Maximize Bioethanol Production by Enhancing Cellulases Adsorption in Novel Bioenergy Amaranthus

Amaranthus is a fast-growing perennial plant containing large amounts of extractable green proteins and lignocellulose residues. However, it remains to explore optimal Amaranthus biomass process technology for biofuel production. In this study, we examined that mild alkali and acid pretreatments (1% NaOH, 2% H2SO4) were sufficient for near-complete biomass enzymatic saccharification, while 8% Amaranthus endogenous proteins were supplemented into the enzymatic hydrolyses. By performing classic yeast fermentation with all carbon sources from directly-extractable sugars and starch and lignocellulose enzymatic hydrolysis, this work achieved the bioethanol yield up to 23.5% (% dry matter). Notably, with respect to extremely high yield of Amaranthus straw, the maximum bioethanol yield was estimated at 14.46 t/ha/year, which was much higher than those of other major bioenergy crops as previously reported. Furthermore, this work proposed a hypothetic model to elucidate how the complete biomass saccharification was achieved to maximize bioethanol production at large scale, based on the effective wall polymer extraction and distinct lignocellulose feature modification for remarkably enhanced biomass porosity and cellulases adsorption. Hence, this work has demonstrated that Amaranthus could be applied as a novel and leading bioenergy crop, providing a powerful strategy for optimal biomass processing towards high bioethanol production.

A study on green pretreatment of rice straw using Petha wastewater and Mausami waste assisted with microwave for production of ethanol and methane

Abstract The present work proposes a new and novel pretreatment of rice straw (RS) using petha wastewater (PWW) and mausami waste (MW) for its conversion to ethanol and methane. This approach is an example of waste-to-waste pretreatment. The organic matter present in the RS has been utilized as the source for biofuel production by the action of the anaerobes present in the microbial culture utilized (cow dung). To enhance the production of biofuel, chemical and green pretreatment methods were compared with respect to solubilisation of the lignocellulosic content into reducible sugars. Maximum glucose release (292 mg/L) was obtained for 2% NaOH pretreated RS followed by PWW pretreatment (198 mg/L). Further 5 min. microwave pretreatment in addition to the above pretreatment methods were also used to enhance the glucose release for production of ethanol and methane. All reactors were operated for two batch runs. The maximum bioethanol yield was 28.75 mg/L (1150 mg/kgRS) for PWW and microwave pretreated RS and methane yield was 11.86% of total gas produced for PWW pretreated RS respectively. This study is based on preliminary experiments on RS with microwave assisted PWW and MW pretreatment for ethanol and methane production.

Optimization and kinetic parameter estimation of bioethanol production from freely available Sri Lankan fruits in batch fermentation

Bioethanol is used in many countries as an alternative to gasoline, mainly due to better emission characteristics. Since Sri Lanka imports fuel for its whole transportation requirement, this research aims optimization and kinetic parameter estimation of bioethanol production from freely available Sri Lankan fruit wastes in batch fermentation. Bioethanol production was carried out using three different freely available overripe fruits in Sri Lankan: banana (Musa spp., embul kesel variety), papaya (Carica papaya) and jackfruit (Artocarpus heterophyllus). Kinetic evaluation of the fermentation process and optimization bioethanol yields were carried out by changing the type of fruits, type of microorganism (Saccharomyces cerevisiae and Pseudomonas mendocino (PM)), concentration of the substrate (1:1, 1:1.5, 1:2 w/w ratio of fruit and water), pH (4.3, 5.0, 5.7), and temperature (27, 32, 350C). Estimation of the kinetic parameters was carried out using Monod and Modified Gompertz equations by fitting experimental data. Optimum parameters found for the fermentation of banana using PM microorganism were 1:1 (w/w) concentration at pH 5 and 350C with a maximum bioethanol yield of 13 vol%. Experimental data were well fitted with Monod model and Gompertz model, with a higher regression coefficient of R2 99.81 and R2 > 99.37 respectively. Comparative to the reported, 12.8 vol% bioethanol yield from banana by fermentation using PM microorganism at room temperature a higher bioethanol yield of 13 vol% could be obtained by fermentating banana fruit mass using PM microorganism with 1:1 (w/w) concentration at pH 5 and 350C temperature.

Yield and bioethanol productivity of sorghum under surface and subsurface drip irrigation

The objective of the present study was to determine the effects of different irrigation levels applied with surface drip irrigation (SDI) and subsurface drip irrigation (SSDI) method on yield and bioethanol productivity of sorghum (Sorghum bicolor L. cv. Early Sumac) in the West Mediterranean Region of Turkey. Field study was conducted in Batı Akdeniz Agricultural Research Institute in Antalya during the growing seasons of 2017−2018. Five different irrigation levels designated as full irrigation (I100) with no water stress and slight (I75), mild (I50), severe water stress (I25) and no irrigation (I0) treatments were applied. The results showed that different irrigation levels applied had statistically significant effect on yield and yield components such as plant height, leaf number, leaf area index, chlorophyll context, brix, sucrose, glucose, fructose and bioethanol. In both of the drip irrigation methods, water deficit stress significantly (P ≤ 0.01) decreased bioethanol yield. The maximum bioethanol yield was obtained from SSDI method under full irrigation, slight, mild, severe and full water deficit stress as much as 2085, 2045, 1684, 1569 and 1407 L ha−1, respectively, in 2017 and 2390, 2266, 1954, 1901 and 1493 L ha−1, respectively, in 2018. The highest water consumption was observed in I100 treatment as 553.6 mm for SDI in 2017, while the lowest was found in I0 treatment as 198.5 mm for SDI in 2018. The highest water productivity was found in I0 as 6.0 kg ha−1 mm-1 for SSDI method in 2018, and the lowest one was found in I25 as 2.9 kg ha−1 mm−1 for SDI in 2017. The results of the present study showed that an average water saving of 24.0 mm compared with the SDI method was achieved without any decrease in efficiency in the SSDI method.

Bioethanol production from the comparison between optimization of sorghum stalk and sugarcane leaf for sugar production by chemical pretreatment and enzymatic degradation

This work reports the comparison of optimized pretreatment models on total sugar (TS) production from sugarcane leaf (SL) with sorghum stalk (SS) utilization to decompose the lignocellulosic biomass into oligosaccharide (OS). The accumulation variables were examined in the pretreatment model, including pretreatment time (1–3 days), concentrations of sodium hydroxide (NaOH) from 1 to 2% (w/v), and heating temperatures from 30 to 40 °C. TS productions were optimized by using response surface methodology (RSM) on central composite design (CCD) models. These models indicated excellent determination coefficients (R2) ranged from 0.9820 to 0.9900 and are significant. Process optimization showed that the highest TS yield was achieved of 32.612 g/L and 38.977 g/L for NaOH pretreatment at condition (2)% (w/v) NaOH at the temperature of 40 °C for 3 days. After pretreatment, the biomass was degraded using a cellulase enzyme to form the fermentable sugar for ethanol production by Saccharomyces cerevisiae TISTR5020. The maximum bioethanol yield of 8.374 ± 1.813 g/L was achieved at 2 days of fermentation time when compared with bioethanol yield (5.234 ± 0.907 g/L) of 4 days fermentation time.

Bioethanol production from Codium tomentosum residue

ABSTRACT The present study investigated the feasibility of using residual biomass of marine macroalgae (Codium tomentosum) for bioethanol production. Influence of various parameters was analyzed for optimization of bioethanol production. Pre-treatment was performed with different acids, H2SO4 concentrations, temperatures, and reaction times. Maximum reducing sugar yield achieved was 16.45 ± 0.33 g/l with 4% of H2SO4 at 100°C for 60 min. Cellulase produced from Trichoderma reesei is used for the hydrolysis of biomass. Cellulase activity was estimated at various pH, temperatures, and reaction times. The partially purified cellulase was found to have more activity at 30°C for 48 h of cultivation at pH 5. Enzymatic hydrolysis was analyzed with various biomass concentrations, enzyme concentrations, temperatures, and reaction times. Fermentable sugar yield of 17.05 ± 0.25 g/l was obtained using 5% (w/v) biomass with 4% (w/v) enzyme at 50°C for 48 h. The fermentable sugar was converted to bioethanol by fermentation using Saccharomyces cerevisiae with different parameters such as different pH, temperatures, and reaction times were executed. The maximum bioethanol yield of 4 ± 0.33 g/l was obtained at 30°C for 72 h at pH 5. Further, the bioethanol content was characterized using GC-MS. Thus, the results shows that Codium tomentosum is an excellent biomass resource that can be used as a renewable feedstock for the production of bioethanol.