Bioethanol Concentration Research Articles

Utilization of robusta coffee waste as a renewable energy material - bioetanol

A research on robusta coffee waste has been conducted as a renewable energy material - Bioethanol. This research was carried out by hydrolysis and fermentation process using Zymomonasmobilis and Saccharomyces cerevisiae (Zymomonasmobilis) bacteria to obtain the best catalyst type in the process of hydrolysis of coffee skin to glucose and the effect of fermentation time on bioethanol content produced. This research was conducted by varying the fermentation time of 7 days; 8 days; 9 days and 10 days. The fermentation fluid was then distilled and tested for bioethanol using a refractometer. Furthermore, bioethanol concentration in the analysis using.

Treatment of Waste Paper Using Ultrasound and Sodium Hydroxide for Bioethanol Production

Bioethanol produced from lignocellulose feedstock is a renewable substitute to declining fossil fuels. Pretreatment using ultrasound assisted alkaline was investigated to enhance the enzyme digestibility of waste paper. The pretreatment was conducted over a wide range of conditions including waste paper concentrations of 1-5%, reaction time of 10-30 min and temperatures of 30-70°C. The optimum conditions were 4 % substrate loading with 25 min treatment time at 60°C where maximum reducing sugar obtained was 1.89 g/L. Hydrolysis process was conducted with a crude cellulolytic enzymes produced by Cellulomonas uda (PTCC 1259).The maximum amount of sugar released and hydrolysis efficiency were 20.92 g/L and 78.4 %, respectively. Sugars released from waste paper were fermented into bioethanol with Saccharomyces cerevisiae. The maximum concentration of bioethanol estimated was 9.5 g/L after 48h of cultivation, the yield and volumetric productivity were 0.454 g/g glucose and 0.2g bioethanol/ L h. respectively. This study of ultrasound and sodium hydroxide treatment may be (we think) it will be a promising technique to develop bioethanol production from waste paper.

Feasibility of high-concentration cellulosic bioethanol production from undetoxified whole Monterey pine slurry

The economic feasibility of high-concentration cellulosic bioethanol production remains challenging because it requires easily available feedstock and low energy consumption process. Simultaneous saccharification and fermentation (SSF) of sulfite pretreated Momentary pine slurry at 20% (w/w) loadings increased ethanol concentration from 59.3 g/L to 68.5 g/L by washing strategy. Effects of inhibitors in pretreatment liquor were further investigated. Besides HMF, furfural and acetic acid, other inhibitors and/or their synergistic effects proved to be responsible for a lower fermentability. To bypass the inhibition and achieve high-efficient bioethanol concentration, a fermentation temperature of 28 °C was optimized for both cell growth and ethanol production. Under the optimal conditions with prehydrolyzed 25% (w/w) whole undetoxified slurry, a high ethanol concentration (up to 82.1 g/L) were produced with a yield of 205 kg/ton Monterey pine in the SSF. Thus, this high cellulosic bioethanol production from Monterey pine makes it a potential strategy for biofuel production.

Prediction of engine performance and emissions with Manihot glaziovii bioethanol − Gasoline blended using extreme learning machine

Bioethanol can potentially replace gasoline because of its lower exhaust emissions. The purpose of this study was to investigate the engine performance and exhaust emissions of Manihot glaziovii bioethanol–gasoline blends at different blend ratios (5%, 10%, 15%, and 20%). Tests were performed on a single-cylinder, four-stroke spark-ignition engine with engine speed was varied from 1600 to 3400rpm, and the properties of the Manihot glaziovii bioethanol–gasoline blends were measured and analysed. The vapour pressure increased for fuel blends with low concentrations of bioethanol due to the oxygen within the bioethanol molecules and the contribution of the flame speed which can enhance the combustion and improved the engine efficiency. In addition, the engine torque, brake power, and brake-specific fuel consumption (BSFC) were measured, as well as the carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide emissions. For a fuel blend containing 20% bioethanol at an engine speed of 3200rpm, the BSFC decreased, with maximum values of 270.7g/kWh. The CO and HC emissions were lower for the Manihot glaziovii bioethanol–gasoline blends. In addition, an extreme learning machine (ELM) model was developed for application in the automotive and industrial sectors. This tool reduces the cost, time, and effort associated with experimental data. The blend ratio of the bioethanol–gasoline blends and the engine speed were used as the input data of the model, and the engine performance and exhaust emissions parameters were used as the output data. The coefficient of determination (R2) was within a range of 0.980–1.000, and the mean absolute percentage error was within a range of 0.411%−2.782% for all the parameters. The results indicate that the ELM model is capable of predicting the engine performance and exhaust emissions of bioethanol–gasoline fuel blends.

Bioethanol Production from Switchgrass Grown on Coal Fly Ash-amended Soil

Potentially toxic concentrations of certain mineral elements may be taken up in plant biomass produced on coal fly ash (CFA) contaminated soil. This raises concerns about efficiencies of downstream processes, such as hydrolysis and fermentation involved in biomass conversions to bioethanol. A greenhouse pot experiment was conducted to assess bioethanol yield from switchgrass biomass produced on CFA-amended soil (0, 7.5 and 15 %, w/w CFA/soil). Separate aliquots of the CFA-amended soils were either inoculated with isolate of arbuscular mycorrhizal fungi (AMF), Rhizophagus clarus, or fortified with reduced glutathione (GSH). Mineral elements in the CFA-amended soils and plant tissues were determined using ICP-OES. Shoot samples of harvested biomass were subjected to microwave-assisted acid pretreatment, enzymatic hydrolysis and fermentation. The reducing sugar (glucose) and bioethanol in the biomass hydrolysate were determined by spectrophotometry. Results showed that CFA had a concentration-dependent increase on the levels of the mineral elements in soils that were amended. Subsequent uptake of the mineral elements in switchgrass tissues was modulated by CFA-soil amendment, AMF inoculation, and GSH fortification. The glucose concentrations in biomasss hyzrolysate of switchgrass grown on 7.5 and 15% CFA-amended soils were significantly higher (p < 0.05) than the unamended (control) soil without significant adverse effect on the bioethanol yield. The bioethanol concentration (µg/mg DW) in the fermented hydrolysate of switchgrass grown on 15% CFA-amended soil (26.63) was higher than the control soil (24.46). Likewise, AMF and GSH enhanced bioethanol yield from hydrolysate of switchgrass biomass grown on the CFA-amended soil. Our results indicated that coupling CFA-amended soil with either AMF or GSH can enhance bioethanol yield.

Comparison of Pretreatment Methods on Vetiver Leaves for Efficient Processes of Simultaneous Saccharification and Fermentation by Neurospora sp.

Lignocellulosic biomass is a potential raw material for bioethanol production. Neurospora sp. can be used to convert lignocellulosic biomass into bioethanol because of its ability to perform simultaneous saccharification and fermentation. However, lignin content, degree of polymerization, and crystallinity of cellulose contained in lignocellulosic biomass can inhibit cellulosic-biomass digestion by Neurospora sp, so that a suitable pretreatment method of lignocellulosic biomass is needed. The focus of this research was to investigate the suitable pretreatment method for vetiver leaves (Vetiveria zizanioides L. Nash) used as a raw material producing bioethanol in the process of simultaneous saccharification and fermentation (SSF) by Neurospora sp.. Vetiver plants obtained from Garut are deliberately cultivated to produce essential oils extracted from the roots of this plant. Since the vetiver leaves do not contain oil, some of harvested leaves are usually used for crafts and cattle feed, and the rest are burned. This study intended to look at other potential of vetiver leaves as a source of renewable energy. Pretreatments of the vetiver leaves were conducted using hot water, dilute acid, alkaline & dilute acid, and alkaline peroxide, in which each method was accompanied by thermal treatment. The results showed that the alkaline peroxide treatment is a suitable for vetiver leaves as indicated by the increase of cellulose content up to 65.1%, while the contents of hot water soluble, hemicellulose, lignin, and ash are 8.7%, 18.3%, 6.8%, and 1.1%, respectively. Using this pretreatment method, the vetiver leaves can be converted into bioethanol by SSF process using Neurospora sp. with a concentration of bioethanol of 6.7 g/L operated at room temperature.

A reusable multipurpose magnetic nanobiocatalyst for industrial applications

A multipurpose magnetic nanobiocatalyst is developed by conjugating Pectinex 3XL (a commercial enzyme containing pectinase, xylanase and cellulase activities) on 3-aminopropyl triethoxysilane activated magnetic nanoparticles. The nanobiocatalyst retained 87% of pectinase, 69% of xylanase and 58% of cellulase activity after conjugation on modified nanoparticles as compared to their soluble counterparts. Thermal stability data at 70°C showed increase in enzyme stability after conjugation to nanoparticles and the kinetic parameters (Km and Vmax) remain unaltered after immobilization. The immobilized enzyme system can be successfully used upto 5th cycle after that slight decrease in enzyme activities was observed. The nanobiocatalyst retained high pectinase activities in organic solvents and chemical reagents as compared to free enzymes. DLS data shows that the nanoparticles size increases from 63nm to 86nm after immobilization. Atomic Force Microscopy data confirms the deposition of enzymes on the nanoparticles. The nanobiocatalyst was used for the clarification of pine apple and orange juice and was also used for the production of bioethanol. Hydrolysis of pretreated wheat straw produced 1.39g/l and 1.59g/l after treatment with free Pectinex 3xL and nanobiocatalyst respectively. The concentration of bioethanol also increases by 1.4 fold as compared to the free enzyme.

Kinetics of Bioethanol Production from Waste Sorghum Leaves Using Saccharomyces cerevisiae BY4743

Kinetic models for bioethanol production from waste sorghum leaves by Saccharomyces cerevisiae BY4743 are presented. Fermentation processes were carried out at varied initial glucose concentrations (12.5–30.0 g/L). Experimental data on cell growth and substrate utilisation fit the Monod kinetic model with a coefficient of determination (R2) of 0.95. A maximum specific growth rate (μmax) and Monod constant (KS) of 0.176 h−1 and 10.11 g/L, respectively, were obtained. The bioethanol production data fit the modified Gompertz model with an R2 value of 0.98. A maximum bioethanol production rate (rp,m) of 0.52 g/L/h, maximum potential bioethanol concentration (Pm) of 17.15 g/L, and a bioethanol production lag time (tL) of 6.31 h were observed. The obtained Monod and modified Gompertz coefficients indicated that waste sorghum leaves can serve as an efficient substrate for bioethanol production. These models with high accuracy are suitable for the scale-up development of bioethanol production from lignocellulosic feedstocks such as sorghum leaves.

Process simulation of hydrogen production by steam reforming of diluted bioethanol solutions: Effect of operating parameters on electrical and thermal cogeneration by using fuel cells

The possibility to exploit diluted bioethanol streams is discussed for hydrogen production by steam reforming. An integrated unit constituted by a steam reformer, a hydrogen purification section with high- and low-temperature water gas shift, a methanator reactor and a fuel cell were simulated to achieve residential size cogeneration of 5 kW electrical power + 5 kW thermal power as target output.Process simulation allowed to investigate the effect of the reformer temperature, of bioethanol concentration and of catalyst loading on the temperature and concentration profiles in the steam reformer. The net power output was also calculated on the basis of 27 different operating conditions.Pelectrical output ranging from 3.3 to 6.0 kW were obtained, whereas the total heat output Pthermal, total ranged from 3.9 to 7.2 kW. The highest overall energy output corresponded to Pelectrical = 4.8 kW, PThermal, FC = 3.1 kW, Pheat recovery = 4.1 kW, for a total 12 kW energy output. This was achieved by feeding a mixture with water/ethanol ratio = 11 (mol/mol), irrespectively of the catalyst mass, and setting the ref split temperature so to have an average temperature of 635 °C in the ESR reactor.

Hydrolysate-Recycled Liquid Hot Water Pretreatment of Reed Straw and Corn Stover for Bioethanol Production with Fed-Batch, Semi-Simultaneous Saccharification and Fermentation

Prehydrolysates and water-insoluble solids (WISs) were produced from reed straw and corn stover pretreated with hydrolysate-recycled liquid hot water (LHW) at different cycle times. The chemical components of the prehydrolysates and WISs were then investigated to assess the possible effects of hydrolysate recycling on bioethanol production. The WISs were subjected to fed-batch, semi-simultaneous saccharification and fermentation (S-SSF) to investigate the changes in bioethanol concentration and evaluate the efficiency of the pretreatment. The pretreatment conditions consisted of a temperature of 195 °C, time of 20 min, and liquid ratio of 1:20. The prehydrolysates were recycled using a circulation volume of 50% and were applied to 10 cycles. The results showed that recycling did not significantly decrease the pH of the hydrolysates. The content of glucose and xylan in the hydrolysates decreased and then increased with increasing cycle times. In the WISs, the contents of benzene alcohol extractives and ash increased remarkably. The content of acid-insoluble lignin and glucan increased slightly. The amounts of xylan and acid-soluble lignin in the WISs were low, and the changes in these contents were not significant. Thus, hydrolysate-recycled LHW pretreatment was beneficial for bioethanol production from reed straw, but not from corn stover.

PEMBUATAN BIOETANOL DARI NIRA AREN (Arenga pinnata Merr) MENGGUNAKAN Saccharomyces cerevisiae

Bioethanol was an alcohol substance which can be obtained by biomass fermentation process. The purpose of this study was to determine the effect of agitation and volume of starter on yield and concentration of bioethanol produced from palm juice (Arenga pinnata Merr). Catalyst used was Saccharomyces cerevisiae. Observed variables were agitation and volume of starter in anaerobic fermentation. The experiment started with preparation of a starter followed by fermentation process. The product obtained from distillation process at temperature of 88 °C. The results showed that the higher agitation speed and volume of starter, yield and concentration of bioethanol will be higher. The highest concentration and yield obtained on the condition at a agitation of 100 rpm and 35% starter amounted to 47.618% (v/v) and 48.1411%. If it exceed that point, the changes of agitation and the addition of starter did not increase the concentration and yield of ethanol produced.

Simultaneous saccharification and fermentation of woody stem Prosopis juliflora by Zymomonas mobilis for the production of cellulosic ethanol

Pre-treatment of lignocellulosic biomass is found to be a pivotal task in the production of biofuels. In this study, woody stem Prosopis juliflora initially was subjected to auto hydrolysis followed by nitric acid treatment (3%(v/v)) and sonication. Further a combination of auto hydrolysis coupled with nitric acid treatment (3%(v/v)) followed by sonication was carried out. The outcome of these two main processes was to ascertain the maximum production of cellulose and hemicelluloses from lignocellulosic biomass and use it for simultaneous saccharification and fermentation (SSF) with commercially available enzyme and gram negative bacteria Zymomonas mobilis in the production of cellulosic ethanol. The process parameters such as pH, temperature, substrate concentration and inoculum volume in the production of cellulosic ethanol were investigated. The maximum bioethanol concentration produced by fermentation of woody stem Prosopis juliflora using Zymomonas mobilis was found to be 16.40 g/l.

Magnesium sulphate and β-alanine enhanced the ability of Kluyveromyces marxianus producing bioethanol using oil palm trunk sap

ABSTRACTThe abundance of oil palm trunk waste generated each year has encouraged research in using its sap for fermentation to produce value-added products. One of these value-added products is bioethanol production using yeast strains. In this study, the ability of Kluyveromyces marxianus ATCC 46537 to produce bioethanol using oil palm trunk sap (OPTS) was examined. The nutrients (ammonium sulphate, di-ammonium hydrogen phosphate, magnesium sulphate, β-alanine, calcium chloride and potassium dihydrogen phosphate) required to enhance production were screened and optimised. The concentrations of bioethanol and sugars were monitored with high performance liquid chromatography. The results showed that K. marxianus could attain maximum bioethanol concentration at 16 h with a higher productivity as compared to S. cerevisiae. Magnesium sulphate and β-alanine were found to increase bioethanol production. When 7.93 g/L of magnesium sulphate and 0.90 g/L of β-alanine were supplemented to OPTS, bioethanol production increased 20% with a bioethanol yield of 0.47 g/g and a productivity of 2.22 g/L.h. Therefore, minimum supplementation of OPTS with inorganic nutrients could enhance the bioethanol production of Kluyveromyces marxianus.

Performance analysis of bioethanol (Water Hyacinth) on diesel engine

ABSTRACTThe increasing consumption and excessive extraction of conventional fuels is the matter of serious concern. Nowadays, world is looking for alternative sources of fuel which can partially replace conventional fuel dependence. The current investigation intends to provide evaluation of bio-ethanol preparation from Water Hyacinth (WH) and its influence on diesel engine performance under various operating conditions. This study explores the extraction of glucose from WH (Eichhornia crassipes) pretreated with sulfuric acid (H2SO4) for production of bio-ethanol. For the production of bio-ethanol different concentrations of H2SO4 acid hydrolysate (1%, 2%, 4%, 6%, 8%, and 10%) were prepared which was then followed by fermentation with cellulose fermenting yeasts. From results, it was observed that 4% H2SO4 acid hydrolysis produces higher concentrations of ethanol than other concentrations. Bio-ethanol extracted from WH was blended with diesel in different proportions (5%, 10%, 15%, 20%, and 25%) v/v and performance and emissions were experimentally investigated on single cylinder diesel engine under various load conditions. Experimental results show that 5 BED [5% bio-ethanol (WH + 95%diesel v/v) and 10BED (10% bio-ethanol (WH + 90%diesel v/v)] produces higher brake power, brake thermal efficiency and brake mean effective pressure with improved exhaust emission profiles than any other blend.

Vapor-phase membrane concentration of bioethanol and biobutanol using hydrophobic membranes based on glassy polymers

Pervaporation and vapor-phase membrane separation methods for the recovery of bioalcohols from dilute aqueous solutions have been critically compared. The importance of taking into account the liquid–vapor equilibrium diagram in studies on the separation of binary aqueous–alcoholic liquid media by these methods has been shown. Previously published experimental data on the transport of water, ethanol, and n-butanol vapors in hydrophobic membranes based on the glassy polymers poly(vinyltrimethylsilane) (PVTMS), poly(1-trimethylsilyl-1-propyne) (PTMSP), and poly(4-methyl-1-pentyne) (PMP) have been analyzed. Schemes of butanol and ethanol recovery by the vapor-phase membrane separation process from fermentation broths for the cases of application of water-selective and alcohol-selective membranes have been presented, as well as the results of mathematical simulation of the process and assessment of energy consumption.

Sugarcane Bagasse as a Carrier for the Immobilization of Saccharomyces cerevisiaein Bioethanol Production

Sugarcane bagasse was used as a carrier to immobilize Saccharomyces cerevisiae in bioethanol production. This research aims to study the potential use of sugarcane bagasse as an alternative carrier for cell immobilization and improvement in the production process of cell immobilization in bagasse. The results showed that the physical characteristics of sugarcane bagasse as a carrier were water content (7.77 ± 0.35%), water retention (4.80 ± 0.44 g/g), water absorption index (8.58 ± 0.22 g/g), and lignin content (24.40 ± 1.52 %). Determination of cell retention was performed in an inoculum volume of 50 mL yeast suspension with various carrier weights (2.5, 5, 10, and 20 g). The highest cell retention was obtained in ratio of 2.5 g carrier/50 mL cell suspension with cell retention of 5.41 ± 1.06 mg/g, or known as biocatalyst. Biocatalyst, as much as 1.5, 3, 4.5, and 6 g, were used as inoculum for a 24 hour bioethanol fermentation. The best concentration and productivity of bioethanol, obtained by using 3 g of biocatalyst, were 23.95 ± 0.28 g/L and 1.24 ± 0.01 g/L/hours. The average of bioethanol yield for a 24 hour fermentation by using immobilized cells was three times higher than the free cells system.

Production of bioethanol from a mixture of agricultural feedstocks: Biofuels characterization

Bioethanol production from a mixture of agricultural feedstock was carried out in a batch fermenter. To study the effect of optimal mixture ratio of fruit juices (100% dates; 70% dates+30% grapes, 50% dates+50% grapes, 30% dates+70% grapes, 100% grapes) on ethanol yield (g ethanol/g sugar), different parameters have been monitored such as ethanol yield, total sugar, ammoniacal nitrogen, pH. It was found that the mixture of Mech Degla dates and grapes juices has the higher bioethanol concentration than that obtained from a single juice from one kind of fruit. Higher bioethanol production 155.5g/L at 72h was obtained when 30% dates juice was blended with 70% grapes juice. In such case, the higher initial sugar concentration is close to 228.34g/L, and the pH droped from 4.5 to 3.87. The Luedeking-Piret model was used to describe the bioethanol production. A good agreement was found between simulated and experimental data. The influence of some physical properties on the addition of ethanol to lead-free gasoline has been studied. It was found that the addition of 5% of ethanol, to lead-free gasoline raises the RON to around 96.4, that can improve its octane number by 2 points.

Techno-economic analysis of different pretreatment processes for lignocellulosic-based bioethanol production

In this work, a method based on process synthesis, simulation and evaluation has been used to setup and study the industrial scale lignocellulosic bioethanol productions processes. Scenarios for pretreatment processes of diluted acid, liquid hot water and ammonia fiber explosion were studied. Pretreatment reactor temperature, catalyst loading and water content as well as solids loading in the hydrolysis reactor were evaluated regarding its effects on the process energy consumption and bioethanol concentration. The best scenarios for maximizing ethanol concentration and minimizing total annual costs (TAC) were selected and their minimum ethanol selling price was calculated. Ethanol concentration in the range of 2–8% (wt.) was investigated after the pretreatment. The best scenarios maximizing the ethanol concentration and minimizing TAC obtained a reduction of 19.6% and 30.2% respectively in the final ethanol selling price with respect to the initial base case.

Development of E30 Bioethanol Fuel Composition Based on Low-Octane Fractions of Exhaustive Hydrocarbon Feedstock Processing

The results of studies aimed at developing E30 bioethanol fuel composition using heavy low-octane hydrocracking gasoline as the basic component are reported. The dependencies of knock resistance, saturated vapor pressure, and fractional composition on bioethanol concentration in a mixture with heavy hydrocracking gasoline are shown. The maximally permissible concentrations of additional components (light hydrocracking gasoline, toluene, and reforming gasoline) in the fuel are indicated. The results of tests of experimental specimens in compliance with OAO VNII NP (OJSC All-Russian Scientific Research Institute of Oil Refining) technical specifications and calculation of economic feasibility of production and use of E30 bioethanol fuel are presented.

BIOCONVERSION OF VARIOUS AGRO-INDUSTRIAL BYPRODUCTS INTO BIOETHANOL BY TWO LOCAL YEAST STRAINS USING STATIC CULTURE TECHNIQUE

Some agro-industrial byproducts [sugar cane molasses (SM), corncobs waste (CW), sugar cane bagasse (SB), sawdust (SD), sugar beet pulp (SBP) and fruit juice waste (FJW)] were used as substrates for bioethanol production by Clavispora lusitaniae Gr45 and Saccharomyces cerevisiae B1 after 3 days incubation at 30°C in static batch culture. Different treatments of these materials as a sole carbon source were applied with or without nitrogen sources (yeast extract or ammonium sulfate). The highest bioethanol concentration when SM is used (13.05 gl-1) was obtained by Sacch. cerevisiae at the treatments: [yeast fermentation medium (YFM) -glucose + 4 % SM], (yeast extract + 6 % SM) and (10% SM), which represent about 10.6 % increase comparing to YFM medium (control). The addition of acid CW hydrolyzate as the sole carbon source to YFM medium was the best of the CW treatments by Cl. lusitaniae Gr45 which recorded the highest bioethanol concentration, productivity, yield and conversion coefficient being, 13.32 gl-1, 0.18 gl-1h-1, 26.64 % and 26.65 %; respectively. These figures were increased to 15.8 gl-1, 0.22 gl-1h-1, 31.6 % and 35.9 %, respectively, on YFM medium containing acid SB hydrolyzate as the sole carbon source. All acid SD hydrolyzate treatments increased bioethanol production by Cl. lusitaniae Gr45 and decreased it by Sacch. cerevisiae B1. The highest bioethanol production obtained on SD was on SD hydrolyzate containing yeast extract followed by SD hydrolyzate only and SD hydrolyzate containing ammonium sulfate being 16.5, 13.76 and 13.54 gl-1; respectively. Using SBP as sole carbon source added to YFM medium decreased significantly the growth and bioethanol production by both strains. Generally, FJW was the best carbon source in YFM medium which increased bioethanol production to about 68 % and 38 % by Sacch. cerevisiae B1 and Cl. lusitaniae Gr45; respectively using static culture technique.