Maximum Ethanol Concentration Research Articles

An exploration of the impact of ethanol diluent on breath alcohol concentration in patients receiving paclitaxel chemotherapy.

This study aimed to provide a better understanding of the impact of paclitaxel chemotherapy on breath alcohol in an Irish population. Patients attending the Oncology Day Unit at Beaumont Hospital were invited to participate on the day of their treatment. The brand of paclitaxel used was Actavis Pharma Inc and contained 6mg/mL paclitaxel in 50% Ethanol/ 50% Cremophor EL. Breath alcohol concentration was measured using the AlcoSense ™ Breathalyser on three separate visits. The primary end-point was the number of patients who were above the legal threshold for drink driving in Ireland. In total, 50 patients were recruited. 36 (68%) were female. The most common diagnosis was breast cancer (56%). Ten (20%) patients had metastatic disease and 4 (8%) had liver metastases. The mean paclitaxel dose administered was 118mg. The mean amount of ethanol infused was 7.7g. 27 patients had a detectable breath alcohol level on at least one visit. The mean breath alcohol concentration was 2mcg/100mL or 0.02mg/L of breath. The maximum concentration of ethanol in exhaled breath was 11mcg/100mL or 0.11mg/L which is 50% of the statutory limit for drink driving in Ireland. A weak correlation was observed between ethanol concentration in exhaled breath and the total amount of ethanol administered. Although no patient exceeded the general limit for drink driving in Ireland, three (6%) participants had a breath alcohol concentration above the threshold for professional, learner or novice drivers. Although definitive conclusions are limited by relatively small numbers, it seems unlikely that weekly paclitaxel infusions pose any significant risk to patients driving.

Studies on Syngas Fermentation With Clostridium carboxidivorans in Stirred-Tank Reactors With Defined Gas Impurities.

Syngas fermentation processes with acetogenic bacteria like Clostridium carboxidivorans have been proven to be a promising approach for the conversion of CO-rich waste gases into short- and medium-chain alcohols. The challenge of synthesis gas impurities, on the other hand, has always been a major concern for establishing an industrial-scale process, since some of the trace components in waste gases, such as NH3, H2S, and NOx, can have inhibiting or even toxic effects on microbial growth and product formation. Thus, this study aims to identify the effects of the main trace impurities in syngas from gasification of biogenic residues by the supply of defined concentrations of trace impurities to the cultivation medium. Autotrophic gas fermentation studies were performed with C. carboxidivorans in batch-operated fully-controlled stirred-tank bioreactors with continuous gas supply (80% CO and 20% CO2). The syngas components NH3 and H2S had a positive effect on both growth and alcohol formation (ethanol, 1-butanol, and 1-hexanol). The maximum biomass concentration was increased by more than 50%, and the maximum ethanol concentration was more than doubled with 5.0 g L−1 NH4Cl or 1.0 g L−1 H2S provided by the addition of 2.2 g L−1 thioacetamide. The addition of the nitrogen oxide species nitrate and nitrite, on the other hand, reduced biomass growth as well as alcohol concentrations. Already, the supply of 0.1 g L−1 NaNO3 resulted in reduced growth and 25% reduction of the maximum ethanol concentration. The production of the longer chain alcohols 1-butanol and 1-hexanol was reduced as well. All NaNO2 concentrations tested showed a strong toxic effect on the metabolism of C. carboxidivorans, and neither CO consumption nor product formation was observed after addition. As a consequence, NOx components in syngas from the gasification of biogenic residues should be reduced by the gasification process and/or selectively removed from the syngas after gasification.

Cellulosic Bioethanol from Industrial Eucalyptus globulus Bark Residues Using Kraft Pulping as a Pretreatment

The pulp and paper industry faces an emerging challenge for valorising wastes and side-streams generated according to the biorefinery concept. Eucalyptus globulus bark, an abundant industrial residue in the Portuguese pulp and paper sector, has a high potential to be converted into biobased products instead of being burned. This work aimed to evaluate the ethanol production from E. globulus bark previously submitted to kraft pulping through separate hydrolysis and fermentation (SHF) configuration. Fed-batch enzymatic hydrolysis provided a concentrated hydrolysate with 161.6 g·L−1 of cellulosic sugars. S. cerevisiae and Ethanol Red® strains demonstrated a very good fermentation performance, despite a negligible xylose consumption. S. passalidarum, a yeast known for its capability to consume pentoses, was studied in a simultaneous co-culture with Ethanol Red®. However, bioethanol production was not improved. The best fermentation performance was achieved by Ethanol Red®, which provided a maximum ethanol concentration near 50 g·L−1 and fermentation efficiency of 80%. Concluding, kraft pulp from E. globulus bark showed a high potential to be converted into cellulosic bioethanol, being susceptible to implementing an integrated biorefinery on the pulp and paper industrial plants.

Ethanol Production from Gmelina arborea Wood Wastes by Saccharomyces cerevisiae using Submerged Fermentation

Lignocellulose wastes are the most abundant residues on the surface of the earth. This project studies the possibility of ethanol production from a forestry waste. Wood wastes from Gmelina arborea were treated with dillute sulfuric acid to break down the lignin component. Fermentation for ethanol production was done using baker’s yeast (Saccharomyces cerevisiae ATCC 204508/S288c) for 120 hours using submerged fermentation, and the pH, reducing sugar, specific gravity and lignin content were determined using standard techniques. Ethanol concentration and yield were measured via vinometer and ethanol standard curve techniques. From the results, the highest pH was obtained at 72 hours of the fermentation period. The reducing sugar content and specific gravity decreased over the fermentation time . The acid-pretreated wood wastes gave a maximum ethanol concentration of 3.84 % and a yield of 7.60 ml/g as measured from the vinometer and ethanol standard curve methods at 72 and 96 hours of fermentation, respectively. About 13.6% v/v of ethanol was recovered from the distillation process employed to separate the components of the product generated after fermentation. The observations in this research reveal the possibility of producing ethanol from G. arborea wood wastes and under optimized culture conditions. This could serve as an alternate means of biofuel generation and hence value addition to the wastes.
 Keywords: Gmelina arborea, Saccharomyces cerevisiae, Ethanol, Submerged fermentation

Single-step ethanol production from raw cassava starch using a combination of raw starch hydrolysis and fermentation, scale-up from 5-L laboratory and 200-L pilot plant to 3000-L industrial fermenters

BackgroundA single-step ethanol production is the combination of raw cassava starch hydrolysis and fermentation. For the development of raw starch consolidated bioprocessing technologies, this research was to investigate the optimum conditions and technical procedures for the production of ethanol from raw cassava starch in a single step. It successfully resulted in high yields and productivities of all the experiments from the laboratory, the pilot, through the industrial scales. Yields of ethanol concentration are comparable with those in the commercial industries that use molasses and hydrolyzed starch as the raw materials.ResultsBefore single-step ethanol production, studies of raw cassava starch hydrolysis by a granular starch hydrolyzing enzyme, StargenTM002, were carefully conducted. It successfully converted 80.19% (w/v) of raw cassava starch to glucose at a concentration of 176.41 g/L with a productivity at 2.45 g/L/h when it was pretreated at 60 °C for 1 h with 0.10% (v/w dry starch basis) of Distillase ASP before hydrolysis. The single-step ethanol production at 34 °C in a 5-L fermenter showed that Saccharomyces cerevisiae (Fali, active dry yeast) produced the maximum ethanol concentration, pmax at 81.86 g/L (10.37% v/v) with a yield coefficient, Yp/s of 0.43 g/g, a productivity or production rate, rp at 1.14 g/L/h and an efficiency, Ef of 75.29%. Scale-up experiments of the single-step ethanol production using this method, from the 5-L fermenter to the 200-L fermenter and further to the 3000-L industrial fermenter were successfully achieved with essentially good results. The values of pmax,Yp/s, rp, and Ef of the 200-L scale were at 80.85 g/L (10.25% v/v), 0.42 g/g, 1.12 g/L/h and 74.40%, respectively, and those of the 3000-L scale were at 70.74 g/L (8.97% v/v), 0.38 g/g, 0.98 g/L/h and 67.56%, respectively. Because of using raw starch, major by-products, i.e., glycerol, lactic acid, and acetic acid of all three scales were very low, in ranges of 0.940–1.140, 0.046–0.052, 0.000–0.059 (% w/v), respectively, where are less than those values in the industries.ConclusionThe single-step ethanol production using the combination of raw cassava starch hydrolysis and fermentation of three fermentation scales in this study is practicable and feasible for the scale-up of industrial production of ethanol from raw starch.

Deconstruction of Woody Biomass via Protic and Aprotic Ionic Liquid Pretreatment for Ethanol Production

Ionic liquids (ILs) have emerged as important solvents for conversion of lignocellulosic feedstocks to fuels and chemicals due to their ability to enable efficient biomass deconstruction and fractionation. Woody biomass derived from forest and agricultural residues has the potential to be used for production of biofuels and its removal from forests can help mitigate disastrous wildfires in fire-prone states like California. This study evaluated woody biomass types (pine, almond, walnut, and fir) from California as potential biofuel feedstocks. The feedstocks were pretreated with the ILs cholinium lysinate ([Ch][Lys]) and ethanolamine acetate ([EOA][OAc]), followed by enzymatic hydrolysis and fermentation of lignocellulosic sugars to produce ethanol. Under optimal conditions, [EOA][OAc] pretreatment and enzymatic hydrolysis generated glucose and xylose yields in the range of 24-82 and 14-80%, respectively, while glucose and xylose yields for the [Ch][Lys] ranged between 28-83 and 23-80%, respectively. Maximum fermentable sugar was released from almond wood, and the lowest amount was from pine and fir. Blends of feedstocks were also explored, and a blend with a mass ratio of 2/2/1 (almond/walnut/pine) resulted in maximum glucose and xylose (>90%) yields using [Ch][Lys]. Fermentation of this hydrolysate using a C5-utilizing strain of Saccharomyces cerevisiae resulted in a maximum ethanol concentration of 17.9 g/L for mixture biomass hydrolysate, corresponding to 60.8% fermentation efficiency. This study represents the first demonstration of the use of these ILs for pretreatment of woody biomass blends that resulted in a high overall conversion efficiency for ethanol production.

An improved enzymatic pre-hydrolysis strategy for efficient bioconversion of industrial pulp and paper sludge waste to bioethanol using a semi-simultaneous saccharification and fermentation process

The current study investigated an integrated fermentation process for efficient conversion of pulp and paper sludge (PPS) material to bio-ethanol. To achieve maximum yield of reducing sugar from the pretreated PPS, most influencing parameters such as enzyme dosages, surfactant dosages on PPS loadings were optimized in a batch saccharification process using response surface methodology. The experimental validation studies under optimal conditions of 6% (w/w) solid loading condition, 0.16% (w/w) of surfactant concentration and 158 FPU/gm of enzyme loading resulted in a maximum reducing sugar yield of 45 ± 3.75% (w/w). Separate batch saccharification studies were conducted with 4% to 7% (w/w) solid loading to formulate best operating conditions for fed-batch saccharification with 13% (w/w), 18% (w/w) and 22% (w/w) high solid loading. The PPS solid loading of 18% (w/w) in fed-batch saccharification resulted in maximal release of glucose and xylose of 79.56 g/L and 8.65 g/L respectively at 60 h. Further improvement in the conversion of PPS to bioethanol was established through adoption of fed-batch semi-simultaneous saccharification and co-fermentation (S-SSCF) process. Fermentation using co-cultivation of two yeast species namely P. stipitis NCIM 3499 and Baker’s yeast resulted in maximum ethanol concentration of 42.34 g/L with 0.53 g/g yield from 18% (w/w) solid loading. Thus, the current study demonstrated the potential application of PPS waste as a feedstock material for ethanol production, which can be adopted by industries as an environment-friendly alternative to common solid waste management.

High efficient ethanol production from corn stover by modified mild alkaline pretreatment

Sodium carbonate pretreatment, an environmentally-friendly and efficient pretreatment, was used to improve solid-state ethanol production from corn stover (CS). To further enhance ethanol yield from the pretreated CS, especially at low enzyme loadings, a combined pretreatment, including steam and sodium carbonate pretreatments, was developed. The removal/modification of lignin by sodium carbonate pretreatment (at 100 °C for 3 h) helped to obtain high ethanol titer at high solids and low enzymes loadings. The maximum ethanol concentration was about 44 g/L, obtained after 72 h simultaneous saccharification and fermentation (SSF) of CS pretreated with sodium carbonate without mixing and prehydrolysis at 30% solid and 15 FPU/g enzyme loadings. Applying prehydrolysis and increasing the SSF time to 120 h improved ethanol concentration to 59 and 67 g/L, respectively. Steam pretreatment at 190 °C for 10 min before sodium carbonate pretreatment led to 76% increase in ethanol concentration. At the enzyme loading of only 5 FPU/g substrate, the modified pretreatment increased the ethanol concentration from 24 g/L to 41 g/L, compared with that of sodium carbonate pretreatment. The results showed that hemicellulose removal and delignification by steam and sodium carbonate pretreatment, respectively, considerably improved ethanol concentration at high solids and low enzyme loadings.

Ethanol production from waste glycerol using glucose as co-carbon source

Ethanol was produced by sole glycerol and glycerol-glucose fermentation using Enterobacter aerogenes TISTR 1468. The initial experiment was set up with waste glycerol as a sole carbon source with initial concentration ranged from 0, 8.7, 23.4, 43.4, to 63.1 g L−1 in 100-mL serum bottles under controlled condition at 30°C for 240-hr fermentation. Liquid samples, during the fermentation, were collected to quantitate concentrations of volatile fatty acids and glycerol, whilst gaseous samples were collected to quantitate CO2 and CH4 constituent. E. aerogenes TISTR 1468 produced maximum ethanol concentration and yield of 215.1 mM and 0.71 mol mol−1 after 72-hr fermentation with the initial waste glycerol concentration of 63.1 g L−1 (equivalent to 79.11 g COD L−1). The ethanol production from glycerol-glucose fermentation was set up based on the initial COD concentration equivalent to 79.11 g COD L−1 with varying glycerol-glucose ratios of 1:1, 10:1, and 100:1. At the ratio of 100:1, maximum ethanol concentration and yield were 232.8 mM and 0.59 mol mol−1 after 24-hr fermentation. Addition of glucose as co-carbon did improve ethanol concentration.

N2 periodic pulsation process intensification to improve ethanol productivity in solid state fermentation of steam-exploded corn stalk

Long fermentation time and high oxygen partial pressure were significant challenges for high ethanol productivity in solid state fermentation (SSF). In this study, the feasibility of N2 periodic pulsation to improve ethanol productivity was investigated. Changes of CO2 concentration and water state distribution in N2 periodic pulsation SSF were examined. A metabolic flux model was developed to understand the effect of N2 periodic pulsation on ethanol production. The results indicated that ethanol productivity of 1.75 g/(L·h) in N2 periodic pulsation group (NPPG) was 34.4% higher than that in control group (CG) within 24 h. The maximum ethanol concentration and yield were 47.52 g/L and 70.80% at 70% moisture content, respectively. The CO2 concentration in NPPG was well below 5000 ppm at 21 h, which was much lower than 38,080 ppm in CG. Metabolic flux analysis revealed that the metabolic flux towards ethanol increased by 25% with the application of N2 periodic pulsation. These results confirmed that N2 periodic pulsation is an effective method for improving ethanol production in solid state fermentation.

Statistical optimization of dilute acid pretreatment of lignocellulosic biomass by response surface methodology to obtain fermentable sugars for bioethanol production

Central composite design to optimize sugar recovery from cotton straw and sunflower straw using dilute acid pretreatment was applied. Selected input variables were acid concentration, retention time, and temperature, as well as the response parameter of sugar yield. The optimum pretreatment conditions observed for maximum sugar yield are temperature: 121.7°C, acid concentration: 2.28% (vol/vol), and time: 36.82 minutes for cotton straw; temperature: 87.03°C, and acid concentration: 3.68% (vol/vol), and time: 36.82 minutes for sunflower straw. Maximum sugar concentrations were corresponded to 20 and 17.5 g L−1 under conditions for sunflower and cotton straw, respectively. This study not only investigates the sugar recovery efficiency statistically but also examines the ethanol production efficiency. As a result, the maximum ethanol concentration, ethanol yield, and ethanol productivity of 7.21 g L−1, 0.41 g g−1, and 0.10 g L−1 h−1 for cotton straw and 8.05 g L−1, 0.40 g g−1, and 0.11 g L−1 h−1 for sunflower straw were achieved via fermentation with Saccharomyces cerevisiae, respectively. The output of this study is important for the commercialization of bioprocesses that enable the conversion of the lignocellulosic waste matrix into high value-added products in a biorefinery concept.

Production of Bioethanol using Waste Fruits under Acid and Alkali Catalytic Hydrolysis: A Review

The present world highly depends on petroleum fuels to gain energy for transportation resulting in the vast side of environmental problems such as global warming and air pollution. Due to this, the price of conventional fuel escalating day by day. Accordingly, the world needs renewable, ecologically suitable, cost-effective alternate against fossil fuels. Bioethanol is one of the most usable fuel or fuel additives among the other biofuels. Ingoing qualities of bioethanol such as high-octane number, high oxygen content, and low energy content are revealed that application of bioethanol produced from different types of waste materials feedstock in the transportation and energy sector diminishes environment pollution. It provides a solution for waste management. The world releases a considerable amount of fruits as waste annually. Thereby, fruit waste is the cheapest feedstock to produce bioethanol. Fruit waste such as whole rotten fruits, fruit peels, seeds and other residues consists of cellulose, hemicellulose, lignin, starch and simple sugars. Conversion of cellulose and hemicellulose to ethanol is vital to advance pretreatment and hydrolysis techniques to obtain maximum ethanol content. The production process of bioethanol from fruit waste mainly contains pretreatment; hydrolysis, saccharification, fermentation and ethanol extracting process (distillation) steps. Yeast (S. cerevisiae) is primarily used in the fermentation process because of its high conversion efficiency, cost-effectiveness and feasibility of handling. Considering the optimum configuration for bioethanol production, simultaneous saccharification and fermentation (SSF) is the best commensurate method having maximum bioethanol concentration. The fermentation process could be appreciated through various factors, such as temperature (30-33 ºC), pH of the medium (4-5), time of incubation, feedstock concentration, inoculum size, agitating rate, N sources in the medium to gain high bioethanol concentration.

Survey of Youth Awareness Regarding Toxic Alcohol (Methanol) and HOOCH Tragedies

The term Toxic alcohol include as a proper name Methanol, and is applied both to the absolute substance further specified by chemists as methyl alcohol, and to its mixtures with smaller proportions of water and slight proportions of other substances. In chemistry, the word alcohol is used as a common or generic name to designate several series of substances containing Ethanol in different percentages. Alcohol consumption has existed in India for many centuries. The quantity of toxicity problem has undergone substantial changes over the past twenty years. In India many deaths are related to intake of toxic alcohol. These are liquors made in India under government license and the maximum Ethanol content allowed is 42.8%. Besides licensed distilleries, a number of small production units operate clandestinely. The toxic alcohol is industrial methylated sprits which regularly cause mass toxicity to humans, who lose their lives or suffer irreversible eye damage and overdose of methanol is death results in this research survey showed that maximum youth are not aware about the toxic alcohols. There is an urgent need to make people aware about methanol toxicity.

Utilization of seawater and wastewater from shrimp production in the fermentation of papaya residues to ethanol

Seawater (SW) and wastewater from shrimp production (WSP) were used as a solvent for the fermentation of papaya residues (Carica papaya) by Wickerhamomyces sp. UFFS-CE-3.1.2 and Saccharomyces cerevisiae CAT-1. For comparative purposes and evaluation of the effect of salinity, ultrapure water (UW) was used as control. Fermentative parameters were evaluated in Plackett-Burman planning to assess ethanol production's significant variables. Urea supplementation was the only variable not significant for the proposed process, suggesting that papaya residues contain all the nutrients needed for fermentation. The experiments conducted with the different water sources resulted in similar concentrations of ethanol. Maximum ethanol concentration was obtained after nine h of fermentation usingWickerhamomycessp. UFFS-CE-3.1.2 (27.31 ± 1.40 g L−1) and 12 h using S. cerevisiaeCAT-1 (24.53 ± 0.68 g L−1). This study demonstrated that SW and WSP could replace freshwater without affecting ethanol production. Papaya residues from the fruit and vegetable sectors can be considered a promising substrate source for ethanol production.

Optimization of two-stage pretreatment for maximizing ethanol production in 1.5G technology

Two-stage pretreatment conditions were optimized to convert corn fiber, separated from whole stillage in a corn dry grind ethanol plant, to fermentable sugars via hydrolysis. Liquid hot water pretreatment (25% solids) at 180 °C for 10 min, followed by three cycles of disk milling, provided maximum glucose, xylose, and arabinose yields of 88.5%, 41.0%, and 30.4% respectively after hydrolysis with Cellulase I. The glucose, xylose, and arabinose yields with Cellulase II at optimum conditions were 94.9%, 74.2%, and 66.3%, respectively. SSF of corn fiber using engineered yeast, with both Cellulase I and II, provided maximum ethanol concentrations of 2.13% and 2.73% (v/v). The protein content in the residual solid after fermentation was 47.95% and 52.05% for Cellulase I and II, respectively. This technology provides additional ethanol in a dry grind plant by converting corn fiber into ethanol and increases the protein content of DDGS, thereby improving the quality.

The study of the main impurities mature mash depending on the duration of fermentation, yeast alcohol race and used enzyme preparations

The paper studied the process of intensification of concentrated fermentation mash with account of the complex amylolytic enzymes, hemicellulase and proteolytic activities. We determined the dependence of ethanol yield, the content of volatile impurities, the content of reducing substances, depending on the different strains of yeast at a seed rate 15 million cells per 1 cm3 wort. To identify the parameters of the fermentation process the wort with an increased solids content, investigated the dynamics of accumulation of volatile impurities by varying the rate and duration of seeding yeast fermentation using 987-O5 race yeast. It revealed that the qualitative composition of impurities in the mash, the resulting wort of high-concentration depends both on the duration of fermentation, and from normal seeding yeast. Thus, depending on the duration of the fermentation process, the acetaldehyde content increases (from 613,17 mg/dm? to 54 h to 1724,6 mg/dm? to 72 hours), the amount of ethyl acetate is reduced (from 409,2 mg/dm? to 54 hours prior to 207 mg/dm? to 72 hours), the methanol content to 54 h at a rate of 15 million yeast seeding cells per 1 cm? of the wort amounted to 0,0043 mg/cm?, whereas by 72 h of fermentation at the same seed rate yeast – 0,0070 mg/dm?, the amount of 1-propanol and 1-butanol was reduced from 903,14 mg/cm? and 6,38 mg/cm? -54 h to 880 mg/cm? and 5,57 mg/cm? - to 72 hours, respectively. The minimum content of isobutanol independent of the duration of fermentation was 900-1100 mg/cm? at a seed rate 15 million yeast cells per 1 cm? wort izoamilola number increases from 1219,08 mg/dm? (54 hr) to 2673,84 mg/dm? (72 h). It revealed that the smallest total amount of impurities obtained by seed rate yeast 15 million cells per 1 cm? wort at the duration of fermentation 54 hours was found that maximum ethanol content in the mash with minimal accumulation therein volatiles corresponds embodiment:. Duration of fermentation - 54 hours at normally the problem of yeast cells – 15,0 million / cm? wort.

Deep eutectic solvent pretreatment of Bambara groundnut haulm for enhanced saccharification and bioethanol production

Five deep eutectic solvents (DES) were screened for their effectiveness in improving biosugar yield in Bambara groundnut haulm (BGH) for bioethanol production. Choline chloride-lactic acid (ChCl-LA) treatment provided the most promising result and was further optimised by investigating the effect of temperature and time on cellulose loss and enzymatic sugar yield. ChCl-LA pretreatment at 100 °C for 1 h was observed to be the best condition for hemicellulose (54.5%) and lignin (60.7%) removal along with optimum sugar recovery of 94.8%. The resulting hydrolysate was concentrated and fermented for 72 h with Saccharomyces cerevisiae BY4743, and a maximum ethanol concentration of 11.57 g/L was achieved with an ethanol yield of 0.38 g/g sugar and productivity of 0.19 g/L/h. From the results obtained, it is evident that deep eutectic solvents are effective for breaking the recalcitrance in BGH due to their high delignification capacity. Furthermore, a recovery of the amorphous glucose and xylose in the BGH prior to DES pretreatment is vital to prevent sugar loss, thereby improving the biosugar yield for bioethanol production.

Effects of Different Incubation Methods on Ethanol Production from SelectedFood Wastes Products

The study describes the potential of producing bioethanol from corn (Zea mays) cobs, collard greens (Brassica oleracea) wasteand banana (Musa acuminate) peels using different methods of incubation. Wastes were pre-treated by grinding into smallerparticles and enzymatic hydrolysis was carried out using commercial cellulase from Aspergillus niger. Anaerobic fermentationwas done using cultured Saccharomyces cerevisiae yeast suspension. Different incubation conditions (incubator, dark roomand under soil) at different temperatures 30oC, 21oC and 19oC respectively were optimised for bioethanol production atdifferent incubation times of 48, 96 and 144 hours. Maximum bioethanol percentages of corn cobs, banana peels and collardgreens were (0.48%), (0.39%) and (0.15%) respectively. The optimum conditions for maximum ethanol concentration in corncobs was the incubator conditions at temperature 30oC and 144 hours; banana peels was under soil conditions at 19oC and48 hours whilst collard greens was dark room conditions at 21oC and 48 hours incubation times. Results obtained show thepotential of producing bioethanol from corn cobs, collard greens and banana peels under different incubation conditions. Useof incubators for fermentation especially in collard greens wastes and banana peels can successfully be replaced with darkroom and soil which are more economically feasible.

Sustainability of Ageratum conyzoides (billy goat weed) for bioethanol and recycling of residues for gaseous fuel production

AbstractAgeratum conyzoides, an herb found throughout the year, is generally considered as a weed: it causes reduction in soil productivity and leads to health hazards for cattle and humans. However, its biomass can easily represent a cost‐effective source, which can be used for lignocellulosic biofuel production. The conversion of lignocellulosic biomass to ethanol has drawn much attention in recent times due to abundance of biomass. In the present study, the cellulose and hemicellulose biomass of the leaf and stem of A. conyzoides was converted to sugars using acid hydrolysis.146.01 ± 02 mg/g of fermentable sugar was obtained from A. conyzoides. The maximum ethanol concentration 11.89 g/L was obtained after 7 days. Scanning electron microscopy was used to characterize the surface morphology after acid hydrolysis of biomass. In the current study, the residues of acid hydrolysis and fermented wastewater was used for biogas production through anaerobic digestion. The yield of biogas from the residues of acid hydrolysis and fermented wastewater was 204 L kg−1VS. The results obtained indicate that A. conyzoides may be considered as a promising feedstock for bioethanol and biogas production.

Sequential bioethanol and methane production from municipal solid waste: An integrated biorefinery strategy towards cost-effectiveness

The organic fraction of municipal waste (OFMW), source-sorted (SS-OFMW) and non-sorted (NS-OFMW), was used as raw material for the sequential production of bioethanol and biogas. Non-isothermal and simultaneous saccharification and fermentation (NSSF) resulted in maximum ethanol concentrations of 51 g/L and 26 g/L for SS-OFMW and NS-OFMW samples, showing overall process yields of up to 80 % and 59 %, respectively, even without subjecting substrate to hydrothermal pretreatment. Subsequently, the solid residues resulting from the fermentation were further subjected to anaerobic digestion (AD), showing a methanogenic potential of 384 ± 6 mL CH4/g of volatile solids (VSin) and 322 ± 3 mL CH4/g VSin, respectively. These methane yields were similar or even higher to those obtained when using non-fermented OFMW substrates (SS-OFMW: 380 ± 18 mL CH4/g VSin and NS-OFMW: 239 ± 4 mL CH4/g VSin), highlighting NSSF as a beneficial step to enhance methane yields during AD. Overall, bioconversion of OFMW would benefit from coupling bioethanol and biogas production since the biogas produced might be further employed as bioenergy source to compensate operational costs.