Raw Material For Ethanol Production Research Articles

Waste Bread as Raw Material for Ethanol Production: Effect of Mash Preparation Methods on Fermentation Efficiency

The issue of managing waste bread is a global concern, with significant environmental and the economic implications. The utilisation of waste bread for bioethanol production, employing energy-saving technology, could prevent these consequences and reduce the consumption of traditionally used fossil fuels. The objective of this study was to evaluate the influence of the type of waste bread (wheat and wheat–rye sourdough) and the mash preparation method on the results of alcoholic fermentation and the concentration of selected congeners in the distillates. The highest fermentation efficiency (96% of theoretical) was achieved for both types of bread through the utilisation of the pressureless starch liberation method combined with simultaneous saccharification and fermentation. The separate saccharification of starch resulted in lower process efficiencies (from 85.75 to 88.60% of theoretical). The application of the native starch hydrolysis method (without starch activation) for the fermentation of wheat bread-based mashes exhibited a higher efficiency (87.85% of the theoretical) than that observed for the wheat–rye bread-based mash sample (83.74% of theoretical). All of the obtained spirit distillates exhibited a low concentration of methanol (≤300 mg/L alcohol 100% v/v) and comply with the requirements of the EU regulation for ethyl alcohol of agricultural origin (rectified spirit).

Cassava hydrolysates used as substrates for the production of second-generation ethanol by Saccharomyces cerevisiae ATCC 26602 immobilized in sodium alginate spheres

Cassava has a prominent position in the Brazilian agriculture and economy. During the production of flour, a very large volume of residue is generated. One way to use these residues is through the production of ethanol. In this context, the present research aimed to use cassava residues as raw material for ethanol production. For this, sulfuric acid was used at concentrations of 1.0 to 5.0% during 5, 10 and 15 minutes of heating in an autoclave. The fermentation was carried out by Saccharomyces cerevisiae ATCC 26602, and to achieve a better performance, it was immobilized in sodium alginate spheres. Ethanol production was also estimated using a synthetic medium added with glucose that served as a comparison standard. The results of the experiment showed that the highest concentration of reducing sugars obtained by the hydrolysis of the residue was with the use of 2.0% of H2SO4 with 15 min. heating at 121 ºC, releasing 56.26 g/L of reducing sugars. The parameters used that led to the highest production of ethanol by the yeast, 7.85 g/L of ethanol, were: pH of 6.5, growth temperature of 30 °C, without agitation. The results showed that cassava residues can be used as a potential substrate for ethanol production. Thus, this work presents data on the most suitable conditions for the use of these industrial wastes in order to generate less polluting fuel energy, an increasingly attractive feature in a world where economic and environmental concerns grow every day.

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.

Revealing Multiscale Interdependence between Ethanol and Corn

One of the key issues nowadays is global warming, while biofuels have been seen as potential solution for this problem. In the recent years, corn is used as a rimary raw material for ethanol production, which means that these two commodities could be highly interconnected. In this regard, this paper investigates time and frequency interdependence between corn and ethanol markets, using the wavelet coherence methodology. As a preliminary result, wavelet power spectrum reveals that increased volatility in the corn and ethanol markets is present up to 16 days and around the two major crisis. The wavelet coherence results clearly indicate that high interconnection does not exist in the short time-horizons, even at the time of the pandemic and the war in Ukraine. This means that various external shocks affect differently the two markets in the short-run. However, the areas of very high coherence are found in the time-horizons from 32 days onwards, which means that the movements of the two markets are pretty much synchronized in the longer time-horizons. This happens because longer time-horizons characterize the lack of idiosyncratic price oscillations, which means that external factors affect the two markets relatively aligned in the long-run. Future studies may use different wavelet techniques, such as wavelet correlation and cross-wavelet correlation, in order to overcome deficiencies of the wavelet coherence method.

Obtaining an aflatoxin-free and high-alcohol-content product using contaminated dried figs

Dried fig is one of the most susceptible products to aflatoxin contamination. Since contaminated figs are not suitable for human consumption and cannot be used for any other purposes, they are burned in a chemical incinerator. In this study, we investigated the potential of using aflatoxin-contaminated dried figs as a raw material for ethanol production. For this purpose, contaminated dried figs (and also uncontaminated controls) were subjected to fermentation and subsequent distillation, and the alcohol and aflatoxin levels were determined during the processes. In addition, volatile by-products in the final product were determined using gas chromatography. Contaminated and uncontaminated figs had similar fermentation and distillation patterns. Although fermentation caused significant decreases in aflatoxin levels, there were still toxin residues in the fermented samples at the end of the process. On the other hand, aflatoxins were completely removed in the first step of the distillation. There were minor differences between the volatile compound compositions of the distillates produced from contaminated and uncontaminated figs. It was shown that obtaining aflatoxin-free and high-alcohol-content product using contaminated dried figs is possible according to the lab-scale conducted studies. Aflatoxin-contaminated dried figs can be used as a sustainable raw material for producing ethyl alcohol that can be used as an ingredient of surface disinfectants and/or fuel additive for vehicles.

Ethanol production using the whole solid-state fermented sugarcane bagasse cultivated by Trichoderma reesei RUT-C30 supplemented with commercial cellulase

Industrial ethanol production usually requires the costly use of commercial cellulase. Herein, we describe the direct use of cellulase produced by Trichoderma reesei RUT-C30 with sugarcane bagasse (SCB) as a substrate for the production of ethanol. The pretreated SCB supplemented with wheat bran (weight ratio of 4:1) was used for T. reesei cellulase production by solid-state fermentation. The cellulase activity titers of 5.5 ± 0.7 FPU/gdm was achieved. The activity increased to 15.0 ± 0.9 FPU/gdm when lactose was used as an inducer. The cellulase contained SCB (CSCB) was used directly as the raw material for ethanol production by Kluyveromyces marxianus at 40 °C, yielding 14.1 ± 1.8% (w/w) of ethanol. Supplementing 5 FPU/gdm of commercial cellulase (Cellic® CTec 2) to CSCB improved the ethanol yield to 30.3 ± 0.4% (w/w). Supplementing Cellic® CTec 2 provided large amount of β-glucosidase activity to CSCB, which hydrolyzes cellobiose to glucose, thereby preventing the inhibition of cellobiose to exoglucanase and endoglucanase. This study demonstrate the feasibility of integrating direct utilization of CSCB without further processing, conversion of CSCB to fermentable sugars, and fermentation of yeast to ethanol in a single reactor. This may be the most efficient way to convert biomass to valuable ethanol.

Pretreatment of barley straw with acid and alkaline solutions to boost the efficiency of fermentable yield enzymatic degradation in the separated fermentation technique for ethanol production

Barley straw is a lignocellulose agricultural waste material that can be utilized as a raw material for ethanol production since it is easy to find, cheap, and has the potential to produce ethanol yield. This research aims to select the optimum pretreatment conditions to increase fermentable sugar production during enzymatic hydrolysis for bioethanol production. Initially, sulfuric acid at a concentration of 0.5, 1.0, 1.5, and 2.0% (v/v) pre-treated barley straw biomass was applied by autoclaving at 121℃ for 15 lb/in2 pressure for 15 min. Furthermore, acid-treated barley straw under the alkaline condition with calcium hydroxide concentrations of 1, 2, 3, and 4% (w/v) was autoclaved at 121℃ for 15 lb/in2 pressure for 15 min. Subsequently, the pretreatment of barley straw in the acetic and alkaline processes was compared. It was found that calcium hydroxide at a concentration of 2% (w/v) gave more sugar concentrations. Finally, combined acid and alkaline pretreatment with 2% of cellulase enzymatic hydrolysis had the highest total sugar concentration of 205.43 g/L and reducing sugar of 134.42 g/L, producing the highest ethanol yield (16.17 g/L) by 24 hours of fermentation.

The NPK1 gene increases sugarcane productivity under water deficit and conventional crop management conditions

The global demand for sugarcane products, such as ethanol, is growing and requires a rapid increase in sugarcane productivity to meet the market needs. On the other hand, water deficit has been successively limiting production in the majority of Brazil and world producing areas. We aimed to assess the industrial quality components and productivity of transgenic sugarcane containing gene NPK1 (Nicotiana protein kinase 1) from tobacco, under with and without water deficit conditions. Two experiments were conducted: one with and another without water deficit using the following genotypes: Agrobacterium and biolistics transrformation methods and a control (no transgenic). The industrial quality parameters ((soluble solids (Brix), Pol, fiber content, apparent purity, reducing sugars (RS), total recoverable sugar (TRS)) and total sugars (TS) productivity were evaluated end of each cycle. The industrial quality components did not differ under normal cultivation. However, the total sugar production per unit area of plants with the NPK1 gene was favored, resulting in a 66% increased from control plants. Under water deficit, the insertion of NPK1 gene promoted improvement of industrial quality components (Brix, Pol, and TRS) and increased by 102% the total sugar production, raw material for ethanol production. The results suggest that the insertion of the NPK1 gene in sugarcane is a promising strategy to increased productivity both under normal conditions and water deficit conditions. They may also indicate a sustainable way to mitigate the increasing global climatic variations that severely affect sugarcane crop.

Ethanol production from olive stones using different process strategies

In this work, olive stone is used as a lignocellulosic raw material for ethanol production. In order to optimise the ethanol production yield, three different process strategies are studied considering the different streams produced in a sequential pretreatment of olive stone with dilute sulfuric acid/steam explosion (SE), which has been previously tested and demonstrated to be an effective fractionation strategy for olive stone biomass. Strategy 1 features fermentation with E. coli SL100 of the mixture of the detoxified prehydrolysate from the dilute sulfuric acid stage and the enzymatic hydrolysate of WIS and detoxified SE liquid fractions. Strategy 2 consists of fermentation with E. coli SL100 separately from the prehydrolysate and the enzymatic hydrolysate of WIS and detoxified SE liquid fractions. Strategy 3 considers fermentation with E. coli SL100 of the prehydrolysate from the acid stage and presaccharification and simultaneous saccharification and fermentation with S. cerevisiae “Ethanol Red” of WIS and detoxified SE liquid fractions. Strategies 2 and 3 reach a similar ethanol production of ∼162 kg/t, which is the highest ethanol yield reported so far from olive stones. The latter strategy uses two different microorganisms that allow an ethanol concentration close to 30 g/L.

Profitability of bioethanol production using cassava (Manihot esculantus crantz) and sweet potato (Ipomea batatas) as raw material

Ethanol imports into developing countries such as Ghana over the past decade have been on the increase. Corn, sugarcane and wheat are major crops that are normally used globally to produce bioethanol. The use of cassava and sweet potato as raw materials for ethanol production has also been demonstrated. Cassava and sweet potato, which grow excellently in Sub-Saharan Africa, could therefore be used as excellent and readily available local raw material for ethanol production to replace the seventy (70) million litres and more of ethanol imported into Ghana in 2016 for various uses. The search for the optimum processing conditions to hydrolyse and ferment sugars from the starches in cassava and sweet potato had been the major focus of all the studies in the past. The price of ethanol produced with cassava and sweet potato compared to the price of ethanol produced with other feedstock in the global market would largely determine the competitiveness and sustainability of producing ethanol with cassava and sweet potato. The objective of this work is to evaluate the cost benefits of ethanol production using cassava and sweet potato as raw materials. Sika bankye (cassava variety) and Apomuden (sweet potato variety) were cultivated and harvested at ten (10) months and three (3) months maturity respectively for the study. Liquefaction, saccharification and fermentation of the cassava and sweet potato varieties to produce ethanol were carried out with Liquozyme SC DS, combination of Spirizyme Fuel and Viscozyme L and Bio-Ferm XR (Lallemand) yeast, respectively. The study indicates that the production of ethanol with a 1:1 mixture of cassava and sweet potato using a 10,000 litres per day capacity ethanol distilling plant generates a net profit of between 9% and 30% over a period of five years. The findings indicate that ethanol production with cassava and sweet potato is a profitable venture. Key words: Cassava, Profitability, Bioethanol processing, Sweet potato, Fermentation, Alcohol yield, Feedstock

A comparative study between ionic liquid and acidic pretreatment of waste cotton textiles with simultaneous saccharification and fermentation

Millions of tons of waste cotton textiles are discarded every year while they could have been used for the production of bioethanol as an alternative for fossil fuel. In this study, the potential of cotton as raw material for ethanol production using ionic liquid (IL) pretreatment and acidic pretreatment is examined and compared, along with non-pretreated cotton samples. The study also aims to determine the optimal temperature of ionic liquid pretreatment, for which experiments under three temperatures (95°C, 150°C, and 175°C) were carried out. Subsequently, the pretreated cotton samples were converted to bioethanol via simultaneous saccharification and fermentation (SSF). Ethanol yields resulting from different pretreatment methods (also non-pretreatment) were compared. Findings suggest that ionic liquid pretreatment under 175°C gives the highest ethanol yield, proving it to be a competitive alternative to traditional acid pretreatment widely applied in industry, as well as demonstrating the prospective usage of waste cotton textiles as biomass for the production of renewable biofuel. Bangladesh J. Sci. Ind. Res. 57(1), 41-48, 2022

Review on technology of making biofuel from food waste

The disposal of food waste has become an environmental issue of great concern with the increasing consumption of materials. The conversion of food waste into biofuels using biotechnology is a very promising approach. Food waste can be converted into fuels such as bio-methane, bio-hydrogen, bio-ethanol, and bio-diesel by different biotechnologies. Food wastes as raw materials for biofuel preparation are mainly classified into protein, fat, starch, sugar, and cellulose. Carbohydrate-rich wastes such as straw, bagasse, grape and apple pomace, and kitchen garbage can produce biofuels, which can be converted into biofuels through anaerobic digestion, aerobic digestion, and microbial fermentation processes. Co-substrates are increasingly used to increase biofuel production and to overcome the shortcomings of a single substrate. The main raw materials for each biofuel are different. Anaerobic digestion technology can be utilized for the production of biomethane, and the digestion efficiency can be changed by the adjustment of the substrate combination, and reactor configuration. The process of methane production by anaerobic digestion mainly includes hydrolysis, acid production, acetic acid production, and methane production. The main raw materials used for methane preparation are livestock manure (pig manure, chicken manure, cow manure, etc.), straw and kitchen waste. Each raw material has a different methane yield and environmental friendliness. Fermentation technology of Saccharomyces cerevisiae can be used to produce bio-ethanol, which consists mainly of raw material pretreatment, enzymatic digestion (saccharification), fermentation, and ethanol production. Cellulosic raw materials (including hemicellulose) are the most promising raw materials for ethanol production on earth, mainly straw, wood chips, peanut shells, and corn. Coupled biomass dark and photo-fermentation technologies can be utilized to produce bio-hydrogen, which includes degradation, dark fermentation, photo-fermentation, and hydrogen production. Food waste containing lipids, proteins, and complex carbohydrates is a good substrate for the dark fermentation stage. The main raw materials for hydrogen production are kitchen wastewater, sugars (glucose), starch (cassava), and cellulose (water hyacinth and rice straw). Hydrothermal liquefaction, hydrothermal gasification, and hydrothermal carbonization technologies can be utilized to produce bio-oil or bio-char. The raw materials for bio-oil/biochar are mainly Edible vegetable oil, nonedible vegetable oil, animal oil, waste edible oil, coffee residue, peanut shell, brewer's grains, grape pomace, sugarcane peel, straw, and wood chips, etc. The industrialization of biofuel technologies is limited by the lack of relevant research and needs to be extensively and thoroughly evaluated. In this paper, the respective advantages and disadvantages of each biofuel technology are clarified and the effects of culture conditions, pretreatment technologies, and reactors on biofuel production are discussed from a technological perspective. In the future, the technology of producing biofuels from various food wastes needs more research in waste conversion rate, product yield, treatment cycle, and cost effectiveness.

Hydrolysis of <i>S. platensis</i> Using Sulfuric Acid for Ethanol Production

S. platensis is a microalga that contains carbohydrate composition of 30.21% which makes it potential to be used as raw material for ethanol production. Hydrolysis of S. platensis is the first step for converting its carbohydrates into monosaccharides. The second step is fermentation of monosaccharides into ethanol. This research aims to study the effect of temperature and microalgae concentration on the hydrolysis of S. platensis using sulfuric acid as catalyst. This research was conducted using 300 mL sulfuric acid of 2 mol/L, hydrolysis temperatures of 70, 80 and 90 °C, and microalgae concentrations of 20, 26.7, and 33.3 g/L. The effect of temperature is significant in the hydrolysis of S. platensis using sulfuric acid. At microalgae concentration of 20 g/L and hydrolysis time of 35 minutes, the higher the temperatures (70, 80, and 90 °C), the more the glucose yields would be (8.9, 13.5, and 22.9%). This temperature effect got stronger when the hydrolysis was running for 15 minutes. Every time the hydrolysis temperature increased by 10 °C, the glucose yield increased by 13.0% at microalgae concentration of 33.3 g/L. At temperature of 90 °C and time of 35 minutes, the higher the microalgae concentrations (20, 26.7, and 33.3 g/L), the higher the glucose yields would be (25.5, 27.7, and 28.2%). The highest glucose concentration obtained was 2.82 g/L at microalgae concentration of 33.3 g/L, temperature of 90 °C, and time of 35 minutes.

Effect of Age of Agave tequilana Weber Blue Variety on Quality and Authenticity Parameters for the Tequila 100% Agave Silver Class: Evaluation at the Industrial Scale Level.

Due to the oversupply and scarcity cycles of the Agave tequilana Weber blue variety, the effect of agave age (harvested in 4, 5, and 6 years) as raw material for the tequila 100% agave silver class was studied for each stage in a full-scale (industrial) process. Harvested plants showed differences in their morphological characteristics that affected the amount of juice; this had an impact in the fermentation stage since must composition was modified in the nitrogen content and juice/exudate ratio. This was noticed due to an increase in the production of higher alcohols attributed to the odd-chain fatty of the exudate, which affects n-propanol production. The characterization of the final product showed the feasibility to use agaves (less than 7 years) to produce the Tequila 100% agave silver class and to comply with the quality criteria. Furthermore, the final product was analyzed with the gas chromatography-isotope ratio mass-spectrometry technique to determine its authenticity. The δ13CVPDB isotopic parameter (−13.40‰ in average) values show the type of plant used as a raw material for ethanol production, while the δ18OVSMOW (20.52‰ in average) isotopic parameter can be helpful in corroborating and ensuring the traceability of the product and the geographical location of the beverage production.

Standardization of a protein extraction protocol for the proteomic analysis of the leaves of Oryza sativa L. cv. BRS AG

AbstractThe rice cultivar BRS AG (Oryza sativa L.) is a cereal developed to serve as a raw material for ethanol production or animal feed, contributing to an increasing energy demand and the economic sustainability of the rice sector. However, only few studies have reported this new cultivar. As proteomic analysis is crucial in understanding the physiological and adaptive behavior of BRS AG rice leaves under biotic and abiotic stresses, the present study compared the following three precipitation protocols for the protein extraction of leaf tissue in two‐dimensional electrophoresis analysis: phenol method, trichloroacetic acid‐acetone method, and a third method developed in our laboratory (BIOPRO). The efficiency and repeatability of the protein extraction protocols were evaluated by two‐dimensional electrophoresis analysis. Our results indicate that the BIOPRO protocol was the most efficient in protein extraction as compared to the efficiency of other protocols. We detected a greater amount of protein (15.44 μg/μL) and 414 spots, and the BIOPRO protocol provided the best results regarding reproducibility, focusing, resolved spots, the intensity of spots, and single spot detection. This novel protocol is useful for extracting high‐quality proteins from leaves and presents an efficient removal of contaminants, which is directly linked to a better resolution for two‐dimensional electrophoresis analysis.

English

The use of cassava and sweet potato separately as raw materials for ethanol production in the recent past has been demonstrated. The search for the optimum processing conditions to hydrolyse and ferment sugars from the starches in cassava and sweet potato is well studied. The effects of substrate, temperature, enzyme types and concentrations, the reaction times of saccharification and fermentation were investigated for effect on ethanol yield. The objective of this work was to combine cassava and sweet potato as raw material to optimise the yield of ethanol for the combination. Selected cassava and sweet potato varieties were cultivated and harvested after 10 and 3 months, respectively. Liquefaction, saccharification and fermentation were carried out with Liquozyme SC DS, a combination of Spirizyme Fuel and Viscozyme L and Bio-Ferm XR (Lallemand) yeast, respectively. The combinations of cassava and sweet potato flours yield more ethanol than processing cassava and sweet potato flours separately. The best combination ratio of cassava and sweet potato, 1:1, resulted in the optimal ethanol yield of 16.2% v/v.   Key words: Cassava, sweet potato, optimization, ethanol yield, combination.

Possibilities and Prospects Regarding Ethanol Production from Saccharin Sorghum [Sorghum bicolor (L.) Moench

Sugarcane has been used as the principal raw material for ethanol production in Brazil, and its adaptability to the country's soil and climate represents an advantage. However, because of the high demand for fuel, coupled with the low production of off-season ethanol from sugarcane, it is necessary to search for other raw materials, such as sorghum [Sorghum bicolor (L.) Moench]. In addition to possessing characteristics similar to those of sugarcane, it can be cultivated in the off-season, thereby ensuring ethanol production throughout the year. This production would boost the regional economy, which is based on ethanol production from sugarcane. The present study proposes the establishment of an industry for the production of ethanol from saccharin sorghum to be implemented in the region of Ribeirao Preto, SP, Brazil. The estimated production of the industry proposed is 500,000 tons of saccharin sorghum per crop. Considering the consumption of approximately 202.25 tons/h, the production of 20 million liters of ethanol could be obtained at the end of the harvest. The company will have a staff of 300 employees, and the implementation at the productive, commercial, safety and environmental levels has been planned in accordance with the appropriate regulations related to the type of industry proposed.

Structural and physicochemical characteristics of taioba starch in comparison with cassava starch and its potential for ethanol production

Starch is an important raw material in the fermentation industry for producing ethanol, which can then be used as renewable biofuel or as a basis for food, drink and pharmaceutical uses. Many tropical starch-producing plants are poorly exploited. Taioba (Xanthosoma sagittifolium) is a subsistence agriculture plant that has high starch content in its tubers but there have been few scientific studies for ethanol production to the present. The objective of this work was to evaluate the structural and physicochemical characteristics of taioba starch and its potential for ethanol production by comparing it to cassava (Manihot esculenta) starch, a well-known and commercially exploited plant. The starch content in the taioba and cassava were 65 and 80 % (DW), which had an amylose content of 21.80 and 23.65 % (DW), respectively. However, taioba starch had a lower proportion of short branched chains (DP 6−12), a higher proportion of intermediate branched chains (DP 13−24 and 25−36) of amylopectin (which are associated to the long term-retrogradation), smaller granule sizes and more densely packed and ordered crystals than cassava starch. It also had higher gelatinization temperatures and enthalpy change, lower peak and breaking viscosities, and a higher final viscosity compared to cassava starch. The hydrolysis (liquefaction and saccharification) reached 52 % and 50 % after 24 h, for cassava and taioba respectively. Maximum ethanol productions were 56 and 48 g/L, productivities were 0.67 and 0.56 g/L/h, yields were 0.49 and 0.46 and fermentation efficiencies were 96 and 90 %, for the cassava and taioba starches respectively. This study has improved understanding of the properties of taioba starch, as well its potential as a raw material for ethanol production.

Process Simulation of Ethanol Production from Jerusalem Artichoke Stalk

Lignocellulosic biomass can serve as raw material for ethanol production. However, lignocellulosic biomass is a complex mixture of carbohydrates that need additional processes for efficient ethanol production, such as pretreatment and hydrolysis before fermented into ethanol. Therefore, this work mainly focused on the creation and simulation of a model of ethanol production from Jerusalem artichoke stalk (JAS) following experimental data and using the commercial software ASPEN Plus with and without a heat exchanger network (HEN). Alkaline hydrogen peroxide pretreatment (AHP) was the first step for this process. The optimal conditions of AHP were a mixture of 2% w/w sodium hydroxide (NaOH) and 4% v/v hydrogen peroxide (H2O2) at 10% (w/v) solid-liquid ratio and 121°C for 90 min. After treatment, 10% AHP-JAS loading was fed to enzymatic hydrolysis at 50°C and the fermentation process at 30°C. The simulation suggested that a feedstock of 60,000 kg of JAS could yield 3,482.16 kg ethanol. The purification section by the extractive distillation system had 12 stages, a distillate to feed mole ratio (D/F) of 0.13, and a reflux mole ratio (R/R) of 1.5. The purity of the ethanol product was higher than 97 wt%. After the model simulation, HEN was designed by using Aspen Energy Analyzer. After the installation of HEN in this process, the ethanol plant with HEN showed a better result, which at 16.24 percentages reduced total cost compared to the process without HEN.

Tea wastes as an Alternative Sustainable Raw Material for Ethanol Production

Integrating sustainability in life became an urgent necessity. Currently tea sectors play important role in adopting new technologies in order to reduce tea wastes .Collection of these wastes for production of ethanol will contribute to the improvement of life and the environment. Simple technique was proposed for saccharification of spent tea leaves either by cellulase or fermentation with baker's yeast. Scanning electron microscope analysis showed certain modification for the morphology of both green and black tea leaves. Brunauer Emmett Teller analysis confirmed the increment in surface area of both tea leaves. X- Ray Diffraction analysis proved the amorphous nature of their cellulose with little crystallinity. This nature eases their saccharification because cellulose is usually susceptible to degradation in its amorphous form. The percentage of produced ethanol was 74.4% from spent green tea leaves and 80.7% from spent black tea leaves after 24 h at mild temperature. The habit of drinking tea in Egypt shed the light on a promising approach relies on the production of ethanol from tea wastes especially spent tea leaves.