ETHANOL FUEL AS FEASIBLE AND DESIRED OPTION IN PAKISTAN

ESDev-2007 – CIIT Abbottabad, Pakistan ETHANOL FUEL AS FEASIBLE AND DESIRED OPTION IN PAKISTAN Aqeel Ahmed Bazmi, Abdul Waheed Bhutto* and Dr. Moinuddin Ghauri ** Department of Chemical Engineering, COMSATS Institute of Information Technology Lahore. [email protected], [email protected] * Department of Chemical Engineering, Dawood College of engineering and Technology, Karachi. [email protected] ** Department of Chemical Engineering, COMSATS Institute of Information Technology Lahore. [email protected], [email protected] ABSTRACT The interest in ethanol as alternate transportation fuel has gathered pace stimulated by high oil prices. Ethanol is being promoted as alternative fuel because of its oxygen content and also because it can be produced from renewable resources. The international market in fuel ethanol is in its initial stage and its full development will require the diversification of production, in terms of both feedstock and number of producing countries. Process of sugar manufacture releases molasses as byproduct. In Pakistan almost all molasses is processed for production of alcohol with efficiency of 250 liters per tonne of molasses. Understanding of the effects of quality of molasses on various process operations and adapting to innovative technological advancements in distillery industry can help in achieving high alcohol yields. The quality of molasses deteriorates during the storage which leads to loss of yield in fermentor. The government of Pakistan has initiated policies to encourage bio-fuel production and usage, with the focus on promoting the use of ethanol for blending with gasoline. In this paper an overview of the alcohol production process in Pakistan is presented. The focus of this paper is on potential technological developments in fuel ethanol production from sugarcane molasses in Pakistan aimed to improve the alcohol yield. KEYWORDS Alcohol production, yeast contamination, yields in fermentation, technological advancements in distillery industry; INTRODUCTION For the last 2–3 decade, due to the sharp increase in petroleum price, there has been a resurgence of interest in large-volume production of fermentation chemicals, and the potential role of a new energy efficient fermentation technology is receiving growing attention. Ethanol continues to be an attractive alternative because of its oxygen content and because it can be produced by fermentation of renewable resources. There is a cutting edge interest 248 in biofuels in connection with climate change mitigation, since stoichiometrically carbon cycle incase of biofuels would follow inevitable closed loop. Fuel ethanol has been used on a large scale since the early 20th century, particularly in Europe. The true potential of alcohol as fuel was not fully exploited due to availability of gasoline at low price. During the oil crises of the 1970s, many countries including Brazil and the United States established programs to use ethanol as an alternative fuel. ETHANOL PRODUCTION TECHNOLOGY Ethanol is produced from the fermentation of sugar by enzymes produced from specific varieties of yeast. Glucose is preferred form of sugar for fermentation for which the organisms and enzymes for fermentation on a commercial scale are readily available. The most beneficial yeasts in terms of ethanol manufacture are from Saccharomyces family; especially S. cerevisiae. The stoichiometric equation for the production of alcohol by fermentation is given below: C6H12O6 C2H5OH Glucose ethyl alcohol + 2CO2 -265kcal /kg cal carbon dioxide Sources of sugar Conventional feedstocks for the production of ethanol include both sugar-based and starch-based feedstocks. The sugar-based feedstocks include crops such as sugar beets and sugar cane. In Pakistan the relatively high market value of sugar has limited implementation of direct conversion of sugar-based feedstocks to ethanol; instead, ethanol is produced through the fermentation of blackstrap molasses a by-product of sugar crystallization. Source of Blackstrap molasses in sugar industry In a cane or beet sugar factory, sugar production process comprises of juice extraction, clarification, evaporation, crystallization and centrifugal separation [1]. Clarified sugar juice is concentrated by evaporation to produce sugar syrup. The sugar syrup then goes through multiple rounds of crystallization to extract the sucrose. It is boiled and the sucrose crystallizes from the remaining molasses fraction. The product of this step is known as massecuite. The massecuite is then centrifuged to separate the sucrose from the molasses. This process is repeated three times in Pakistan’s sugar mills. Thus clarified sugar juice is boiled and centrifuged the first time to produce ‘A’ sugar and ‘A’ molasses. ‘A’ molasses is then boiled again to produce ‘B’ sugar and ‘B’ molasses. The ‘B’ molasses is boiled a third time to produce ‘C’ sugar which is mixed with water and is used to seed the next round of crystallization. The ‘C’ molasses is referred to as ‘final’ or ‘blackstrap’ molasses. Blackstrap molasses is a syrup containing mixture of un-crystallizable sugar, non-sugar solids originating from cane or beet, chemicals from the sugar manufacturing process and some water. It contain approximately 50 percent sucrose and 50 percent other components that include water, various organic components (other than sucrose) and inorganic salts. The color, taste, odor and composition of molasses vary with the type of raw material and also with stage of exhaustion (sugar extraction) of the molasses. Blackstrap molasses differs from other feed stocks for alcohol production such as corn, sorghum and potatoes etc. which have their carbohydrate contents stored as starch which is usually precooked and hydrolyzed into fermentable sugars. Molasses doesn’t require pretreatment as the carbohydrates are already in the form of sugars [2]. It is a non-sterile process and presence of undesirable microorganisms in the process cannot be completely avoided. The raw material used for fermentation itself shows the presence of contaminating microorganisms. The major cause of concern in molasses based fermentation for ethanol production is the presence of wild yeast along with bacterial contamination. Ethanol Production Distilleries in Pakistan are using cane blackstrap molasses as a feedstock for alcohol production. The final cane molasses contain about 50 weight (wt) percent total sugar. This is diluted to about 15-wt percent sugar to make a 249 fermentable solution. pH is adjusted around 4.0 -5.0 by addition of sufficient sulfuric acid. This mixture constitutes the mash, and appropriate strain of yeast is added to it, which has been growing in a yeast tub. The yeast makes up about 5 percent of total volume added to fermentor. The fermentation is allowed to take place at 75oF. The chemical reaction liberates a significant amount of CO2 and heat. The fermentation process can be conducted in batch or continuously, using open or closed fermentation tanks. According to industry sources, average ethanol recovery from one tonne of molasses is estimated at 240 to 270 liters depending on the quality of molasses. After fermentation raw alcohol solution containing about 7 to 15 percent by volume is distilled from other byproducts, resulting in a level of purity of approximately 95%. This is often referred to as hydrous ethanol. However for its application as gasoline blend it has to be dried to less than 1% moisture. FACTORS WHICH IMPACT PRODUCTION A successful ethanol production and conversion system that is both economically feasible and environmentally sustainable requires the amalgamated application as a host of component technologies in a holistic and integrated manner, such that economic risk for the investment is minimized. Not all inputs and losses for the component systems can be completely controlled through process design, the goal is to minimize the cost of both controllable inputs and losses. For the conversion facility, minimizing inputs is beneficial for economical ethanol production. Growing yeast High yielding and efficient fermentation of molasses with varying composition requires selection of special yeast strains having high tolerances to inhibitory conditions as well as ability of fast fermentation. This is normally expressed in terms of specific productivity and specific growth rates on a given molasses. Other natural requirements like tolerance to high alcohol, sugar and temperature are also necessary. Several different organisms have been proposed for use in fermenting sugars to ethanol, with different strains of the yeast, Saccharomyces cerevisiae, is the most widely used due to its robust growth rate and high ethanol tolerance [3]. With proper nutrient and growth conditions, it has been shown that S. cerevisiae can tolerate ethanol concentrations up to 23% [3]. The yeast S. cerevisiae and the bacterium Zymomonas mobilis are highly efficient in alcohol fermentation but they cannot use many source of sugars substrates. Therefore, there is a great interest in development of recombinant microorganisms which combine the efficient alcoholic fermentation observed in S. cerevisiae and Z. mobilis with the capacity to utilize a broad variety of sugar substrates [4]. There is an interest in the use of thermo tolerant yeast in thermophilic ethanol production [5-6], due to the potential for higher fermentation rates and ethanol yields, and the reduced requirements for cooling. Nevertheless, to date, thermophilic fermenting organisms have suffered from low ethanol tolerance, presumably due to leaky cell membranes at the higher temperatures [6]. The bacterium, Zymomonas mobilis, has been shown to produce higher ethanol yields due to a lower cell yield, but its lower ethanol tolerance. The bacterium, Zymomonas mobilis, has been shown to produce higher ethanol yields due to a lower cell yield, but its lower ethanol tolerance and lower feed by-product return has limited its widespread application [7]. Difficulty of separation, lower cell yield, and concern for pathogenic contamination in feed have limited the market for bacterial feed additives. In contrast, yeast are more easily separated, generally accepted as safe in feeds, and have an established market[8]. Actively growing yeast produce alcohol up to 33 fold faster than non-growing yeast, the objective should be to keep the yeast growing as long as possible to the highest cell yield to ensure predictable fermentation times. Nutrients can deficient and affect yeast metabolism. These nutrients include (but are not exclusive) oxygen, phosphate, sulfate, magnesium, calcium, zinc, a whole spectrum of other ions and vitamins. Calculations can be carried out for each based on the total amount of yeast likely to be found in the fermentor. In industry, most ions and vitamins are normally present in the mash or added as “yeast food”. 250 Molasses quality plays influential role in the outputs and efficiencies of alcohol production. Experience, understanding of the effects of composition on various process operations, and adapting to innovative technological advancements to effectively and positively control the effects; can help in achieving consistently high alcohol yields Wild Yeast Wild yeast occurs naturally in the raw material and produce small amounts of alcohol. Report suggests that they can be harder to detect and control than bacteria [9]. Generally the wild yeast Dekkera and Brettanomyces are observed inhabiting molasses source. ). Dekkera species can also be fermentative yeast capable of producing alcohol. They are genetically identical but Dekkera is the sporulating form of this yeast. Brettanomyces grows and ferments slowly and can ferment in low levels of fermentable sugars [10-11]. 1. Sources of Contamination Wild yeast primarily comes through molasses in the fermentation process because of the presence of fermentable sugars. Solid addition as well as liquid streams entering the process can also be a source of wild yeast contamination [3]. 2. Problems Caused by Wild Yeast Contamination In the fermentation process, yeast multiplies in the form of heavy branched structure. This branching yeast comes at the top of the fermentor. The sparging of air in the fermentor helps the branched yeast to rise to the top and form a thick layer called the ‘scum’. The scum formation in the fermentor traps gas bubbles inside the branched structure thereby building pressure in the fermentation vessel. Increasing scum leads to weaker controls in the fermentation process which is the major problem is caused by wild yeast. This scum cannot be reduced by the addition of anti-foaming agents. The process needs to be stopped after a few weeks due to a loss of efficiency and overflow of mash from the fermentors. There is washout of culture yeast and a gradual drop in the alcohol concentration in the fermentation process. According to Lorenz et al. [12], the morphological changes in the culture yeast (Saccharomyces cerevisiae) leads to filament formation under unfavorable fermentation conditions. This causes scum formation and foaming. The budding yeast S. cerevisiae, starved for nitrogen, differentiates into a filamentous growth form. In nitrogen poor conditions leucine, the precursor of iso-amyl alcohol can also induce elongation of cells. Ceccato-Antonini,[13] suggested genetically controlled morphological changes and filamentous growth in response to Isoamyl alcohol. According to Lorenz et al [12], the reduction in efficiency is attributed to the presence of wild yeast and bacterial contamination in the input to the fermentor. Due to heavy foaming, juice losses result in the loss of alcohol. The efficiency reduction depends upon the extent of contamination. 3. Killer Yeast Strains There are widespread occurrences of killer phenotypes in yeasts in alcoholic fermentation. Many of these fermentative processes use non-pasteurized medium, which can enhance the predominance of wild yeast. These contaminants can contribute to the fermentation rate decrease or blockage, increases in acidity, fusel oil production, and an overall decrease in ethanol production. Isolation of killer yeast strains from the ethanol process is imperative for good yields. The presence of cultured yeast with "killer" tendencies against wild yeast will help overcome the problem of excess growth of wild yeast contamination during the process [13]. Sugar cane molasses are normally pasteurized or decontaminated in order to reduce the amount of microorganisms appearing during its production, transportation, or storage. Usually, heating the molasses above 76.6°C reduces lactic bacteria but also decreases viscosity and precipitates calcium. High concentrations of suspended solids also make pasteurization inefficient. Furthermore, the availability of good quality molasses depends on the efficiencies of the specific sugar refineries, weather conditions, and harvesting techniques. Unfortunately, these variables lead to an inconsistent supply of good quality sugar cane molasses and a constant dilemma for sugar cane molasses distillers [14]. It is not altogether necessary to sterilize molasses. However, there are advantages in terms of alcohol yield and purity when pre treating the molasses. Treatment of the 251 molasses solution by means of heat and sulfuric acid will precipitate undesirable salts and help to improve the purity of alcohol obtained and reduce the amount of scaling. Nutrient Supplement The vital risk factors for Dekkera growth include residual sugar and nitrogen present in the fermentation medium. Nitrogen is supplemented in the form of Diammonium Phosphate (DAP) or urea to control fermentation. This can lead to the excess growth of Dekkera due to the presence of excess nitrogen left over during fermentation. Hence the quantity of nitrogen added to the fermentation process should be adequate only to help growth of culture yeast. According to Lorenz ed al. [12] S. cerevisiae can change its morphology due to an inadequate nutrient supply. In this case, the proper supply of nitrogen should be used to overcome the morphological changes in culture yeast. Quality of molasses Normally 60-70% of the production cost is contributed by the feedstock in alcohol production. Owing to the increasing demand and cost of molasses, improving and maintaining the quality of the fermentation process has become a crucial factor. The key parameters that determine the quality and fermentation potential of sugar cane molasses are sugar content, minerals, suspended solids and acidity. High concentrations of calcium and chlorides negatively affect the alcoholic fermentations of cane sugar molasses, while minerals like magnesium and zinc exert a positive effect on yeast health and productivity. During sugar production operations, juice-holding time, exposure temperature and addition of chemical affect the composition of molasses. High temperature along with high or low pH increases sugar caramelization. Use of lime, sulfur and CO2, increase the content of calcium and carbonates in molasses. Use of antibiotics or a very high count of yeast cells are needed to overcome the bacteria that hide behind suspended solids. These biocides are extracted in molasses as residuals, and affect the yeast in distillery fermentation. The acidity of sugar cane molasses varies depending on the harvesting techniques. Very high acidity content on cane sugar molasses is detrimental to yeast fermentation. Finally, the quality of sugar cane molasses varies depending on its geographical origin and on the time of harvest. Molasses as it is produced from the centrifugal stage is in a hot condition (52 to 55oC). Due to the chemical treatments, it contains large amount of sulfurous gases. Sulfurous gases can inhibit yeast. Similarly fresh molasses has high foaming tendency as well as high buffering capacity. It also contains high level of suspended sludge. Processing of fresh molasses usually results high microbial count in distillery fermentation. This is why fresh molasses is stored for at least a month before use in a distillery. During storage the first evidence of thermal degradation is production of frothing due to evolution of CO2 by reaction of invert sugar with amino acid. Frothing is accelerated by high temperature. Even at normal temperature molasses undergoes very slow degradation in storage, usually with evolution of CO2 [4]. Cooling and frequent mixing by recirculation during storage helps to avoid internal combustion and caramelization. Molasses, if not cooled properly, also promotes the growth of heat stable microbes that affects fermentation. At higher temperatures, generally in summer, wild yeast is produced in high quantities [15]. Increasing storage time (more than six month) on the other hand can reduce the fermentable sugar content slowly. Molasses is stored in steel tank to prevent contamination. Prolonged holding of liquor at low temperature and inadequate mill sanitation, increases the microbial contamination and acids in molasses. Proper sanitation during storage of molasses is also necessary to avoid the microbial contamination. Contact with water and pockets of dilution in bulk stock, can give rise to high microbial flora. Contact of soil with molasses also should be avoided. It is necessary to handle and store in protective environment, taking above-mentioned factors into consideration [15]. Sulfur Dioxide and Sulfite Solutions The principle source of SO2 is sodium bisulfite or potassium metabisulfite. Potassium metabisulfite contains approximately 55% SO2 by weight. This free SO2 kills the microorganisms [10]. Culture yeast is generally tolerant to SO2, but at higher concentrations it shows loss of viability. SO2 is toxic and requires appropriate 252 handling. SO2 binds to various compounds present in molasses or juice and pulp or the compound formed during fermentation. Hence the dose should be optimized so that the deleterious effect on wild yeast is achieved without harming the culture yeast. The concentration should be sufficient to overcome the efficiency loss caused by binding to the compounds during fermentation. Generally the dose should be optimized in order to achieve the proper results. The total SO2 added to any wine is under 100 PPM. Process Parameters Pasteurization of molasses can help control wild yeast and bacteria. Contaminants generally occupy surfaces covered with deposits of starch, sugar, protein or mineral rich materials. Contaminants thrive in places that are hard to clean such as, porous surfaces, cracks, sharp angles, corners, gaskets, valves, pressure gauges, in-place thermometers, and pump packing. Deposits in these areas protect the organisms in them from heat and sterilizing solutions. According to Abbott et al., [16] the growth rate of Dekkera wild yeast is lower than culture yeast S. cerevisiae and hence their ability to compete with S. cerevisiae is hindered in batch fermentation. Due to different reaction rates Dekkera produces different end products as they ferment the juice sugars to alcohol. Considering this fact, the cell concentration of the culture yeast can be higher but suppressed if wild yeast outnumbers the culture yeast. Recycle of yeast builds up higher population of yeast in the fermenting mash, thus giving higher productivity as well as robustness of operation [17]. There are processes that allow the yeast cell concentration in the fermentation process to be increased. Yeast recycling is one of the most common methods. This process maintains desirable cell concentration for healthy fermentation. Maintaining the population of contaminants at lower levels and the use of proper operating procedures is key to the fermentation process. FERMENTATION TECHNOLOGICAL In Pakistan the efficiency of industrial fermentation is currently low and can be improved with further technological innovation. Instrumentation and process control, utilization of flocculent yeast, and processes with immobilized cells will have important roles in the technological evolution. Batch and fed-batch processes (FBP) have been traditionally used for fermentation of ethanol. Factors that traditionally favored batch and fed-batch fermentations include high substrate conversion, factors associated with separations, and mitigation of contamination problems. Continuous fermentation (through increased yeast concentration) has become a valued alternative to batch processing. Potential advantages include significant productivity improvements and improved control of microbial environments. For example, a number of schemes have been developed for reducing washout to obtain and maintain high productivity. These strategies include cell recycle by filtration, sedimentation, entrapment by membranes, and immobilization in gel beads [18-19]. The high volumetric flow rates and retained biomass concentrations give cultured bacteria a distinct ecological advantage over unwanted microbes in these settings. Under some circumstances, pH and other factors can be easily controlled in continuous reactors for mitigating the growth of contaminants. Continuous processing increases the productivity of fermentation, i.e. the amount of ethanol fermented per liter volume per hour. The continuous fermentation method is the most appropriate, no matter which process we choose: free cells, flocculent cells, or immobilized cells [20]. Fermentation with immobilized yeast [21] or recycled yeast [22] is advocated for potentially higher fermentor productivity and ethanol yield, mostly due to a decreased yield of yeast organisms. When compared with processes using immobilized cells, alcoholic fermentation using free cells offers some advantages: the larger area of contact between cells and nutrient medium and the management of current technology. However, disadvantages include the higher costs of microbial recycling and installation, high contamination risks, susceptibility to environmental variations, and the limitations of the dilution rate in continuous fermentation due to wash out [20] . Very High Gravity (VHG) fermentation is defined in the fuel alcohol context as the preparation and fermentation of media containing 300 g or more dissolved solids per liter. VHG fermentation of saccharine substrates lead to moderate increases in alcohol concentration as compared to alcohol concentration presently 253 achieved in industry [23]. The technology when implemented will allow close to double the ethanol content of the fermentor - an increase from 7-10 to 15-18 + % v/v or more. It is achieved in a number of ways, but nutrition for the yeast is one obligatory requirement. Without proper nutrients, we see stuck and sluggish fermentations fermentations where the rates of sugar utilization are extremely slow especially near the end of fermentation. Residual sugars are left unfermented in the mash (sugar bleed). They are especially a problem in very high gravity conditions where sugar concentration is high and total solids are well above 20% w/v. Stuck and sluggish fermentations are not only caused by inadequate nutrition, but also can be caused by stress (ethanol, osomotic tolerance, pH tolerance, temperature and the end products made by bacteria, wild yeast, and even yeast themselves. Microbial contamination (competition for nutrients), and any factors reducing vitality or viability also lead to such problems. To implement VHG fermentations, a number of steps must be taken. They can include one or more of the following; (i) Prepare mashes with increasingly high solids (less water) - you can’t make higher ethanol without more potential sugar, (ii) Remove solids (with rinse) prior to fermentation - if it can be done, (iii) Supply sterile oxygen to the fermentation - cold side of heat exchanger - 20 ppm or about 5 ppm/hour - needed for strong yeast cell membranes. High productivity reduces the volume capacity required for fermentation tanks, thereby reducing costs. In distilleries, low steam utilization technologies have been introduced through heat integration using waste heat in heat exchangers, which is then re-used to increase the temperature and/or pressure of other processes. Such an approach uses less steam and leaves more steam for electricity generation, thereby improving the economics of production. THE ECONOMICS OF ETHANOL IN PAKISTAN In Pakistan presently 16 distilleries are in operation with installed alcohol production capacity of 506.33 million liters which require around 1.687 million tonnes molasses. Country’s distillery industry only process molasses a byproduct of sugar industry and almost all distillery plants are attached to sugar industry. Process of sugar manufacture releases the molasses which is on average 4% by weight on the quantity of cane, or 40% on the sugar produced. In Pakistan distillery industry normally operates for 250 days with the alcohol production efficiency of 250 liters (240 Kg) per tonne of molasses [24]. In the country, sugar mills generally do not have proper storage system of molasses and normally most of the mills store the produce in open and in kutcha pits, which are exposed to atmospheric changes as well as dirt. Very few mills had steel tank storage facilities. The poor sanitation condition deteriorate the quality of molasses, at the same time the molasses is contamination by microbial. The contaminated molasses when processed in distillery give lower yield. For the last couple of years molasses is converted into three grades of alcohol i.e., fuel or anhydrous, neutral or extra-neutral (ENA) and industrial or rectified ethanol (REN). The fuel grade alcohol fetches highest price as it is being growingly used for mixing up to 10 percent in petroleum products the world over to ease the pressure of increasing oil prices. The fuel grade alcohol needs 99.80 per cent purity on conversion from molasses while neutral (ENA) is purified up to 96.20 per cent and is used by pharmaceutical industry and in the making of wine. The industrial grade, also known REN, requires 94 per cent purification and is used by the industry. Pakistan mostly exports its ethanol to the European Union (EU). The cost of EU-produced bio-ethanol makes it difficult for them to compete with fossil fuels. Due to lower production cost, Pakistan took a big lead over the other Generalized System of Preferences (GSP) beneficiaries with export of 141.3 million liters to EU in 2004 (the second largest exporter in the world) [25]. However the new EU Regulation (EC) No 980/2005 of 27 July 2005, which applies from 1 January 2006 to 31 December 2008, no longer provides for any tariff reduction for either denatured or un-denatured alcohol under code 2207 (still classified as a sensitive product) to Pakistan [25]. Nevertheless, at production costs of US$ 0.1452/liter, Pakistan is closer to Brazil’s, production costs of US$ 0.1355/l, and has manages to export substantial quantities to the EU despite paying the full MFN duty [25]. Pakistan has exported around 212.164 million liters of alcohol during 2006 to earn around $100.6 million [24]. The average price fetched by exporters for different grades of alcohol ranged around $560 to $680 per tonnes for 254 different grade of alcohol. Pakistan is therefore be expected to continue to be able to export significant quantities of ethanol to the EU, thus utilizing the increased production capacity built over the last couple of years. During current 2006-07 sugarcane crushing season country is expected to produce around 1.8 to 2 million tonnes of molasses. Country would easily manage to produce 506.33 million liters of alcohol during current 2006-07 sugarcane crushing season on getting around 1.8 to 2 million tonnes of molasses if all the available molasses is processed in distilleries. The introduction of ethanol in petrol in Pakistan will also boost its domestic consumption. Pakistan’s expected consumption of petrol in the year 2005-06 was estimated around 2285.714 million liters, hence if the country starts blending ethanol with the ratio of 10%; it will require 228.5714 million liters of fuel ethanol. The local consumption can be further increased by setting naphtha/ ethanol power plant. Country’s distillery sector has capacity to meet its domestic requirement as well as export substantial amount to EU and other countries if additional molasses are made available. CONCLUSION The rising trend in oil prices is gradually shifting the economic balance favorably towards bio-fuel manufacture. The technology breakthrough is creating a paradigm shift in the way we make transportation fuel. The production cost of ethanol in Pakistan is low and country has managed to export substantial quantities to the EU despite paying the full duty. Pakistan’s distillery industry has capacity to meet its domestic requirement as well as export substantial amount to EU and other countries if additional molasses are made available. The introduction of ethanol in petrol in Pakistan will also boost its domestic consumption. The supply of feedstocks is crucial to the success of the bio-ethanol strategy. Feedstock costs account for 60 to 70% of the total cost of ethanol. The availability of quality feedstocks could be improved by improving storage facilities. Wild yeast contamination can lead to serious problems including scum, foaming, and the loss of yield in fermentation. The widespread occurrence of these problems challenges the industries and scientific community to look forward and contribute to the management of wild yeast contamination. Further study of this topic is obviously warranted. The sugar factory process along with handling, storage and transportation of molasses is vital towards managing the contamination of wild yeast. Experience, understanding of the effects of composition on various process operations, and adapting to innovative technological advancements to effectively and positively control the effects; can help in maintaining consistently high alcohol yields with minimum needs of process inputs. Time of fermentation, ethanol yield, and fermentation efficiency improved with optimization of the fermentation process and implementation of new technologies. 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