Skip to main content
UploadLanguage (EN)Support
BusinessMobileSocial MediaMarketingTechnologyArt & PhotosCareerDesignEducationPresentations & Public SpeakingGovernment & NonprofitHealthcareInternetLawLeadership & ManagementAutomotiveEngineeringSoftwareRecruiting & HRRetailSalesServicesScienceSmall Business & EntrepreneurshipFoodEnvironmentEconomy & FinanceData & AnalyticsInvestor RelationsSportsSpiritualNews & PoliticsTravelSelf ImprovementReal EstateEntertainment & HumorHealth & MedicineDevices & HardwareLifestyle
manojjeya, profile picture
Uploaded bymanojjeya
PPTX, PDF3,611 views

Ethanol Production, Biofuel Production

This document summarizes the process of ethanol production. It discusses that ethanol is produced through the fermentation of sugars by microorganisms like yeast and bacteria. The key raw materials used are sugars, starches, and lignocellulosic biomass from crops like sugarcane, corn, and wheat. The production process involves milling and liquefying the raw material, saccharification to convert starches to sugars, fermentation of sugars to ethanol, distillation to separate ethanol from water, and dehydration to produce anhydrous ethanol. Byproducts like dried distillers grains and carbon dioxide are also discussed.

Environment◦
Downloaded 26 times
ETHANOL PRODUCTION BY A.MANOJ KUMAR B.Sc., M.SC. SRI KALISWARI COLLEGE(AUTONOMOUS) SIVAKASI
INTRODUCTION Biological process in which sugars (glucose, fructose, sucrose) are converted into cellular energy. Ethanol is produced in the result of this process. It is colorless, volatile or flammable liquid. It is widely used as biofuel as well as an alcoholic beverage is increasingly being consumed globally. This is mainly because of the cheap raw materials available.
RAWMATERIAL Ethanol can be derived from either sugar, starchy materials or lignocelluloses. The main feedstock for ethanol production includes sugarcane, sugar beet, corn, wheat. Sugars: Sugarcane (molasses & juice) Cane sugar (clarified concentrated syrup) Sugar beet Starchy materials: Corn Wheat Sweet sorghum Lignocellulosic material: Sugarcane bagasse Corn stover Cereal straws
FEEDSTOCKCONDITIONINGANDPRETREATMENT Dilution: Molasses must be diluted to below to 25 °Bx (Brix) as yeast start to ferment quickly at this concentration. Sedimentation: To prevent any incrustation in the pipelines or distillation towers due to ash content in molasses greater than 10%. The special chelating agent can also be used to remove the incrustation. Addition of org & inorganic compounds: Done to offset the negative effect of salt which in turn increases the osmotic pressure. Yeast strains resistant to salts are also developed. Microfiltration: To remove the impurities that stick to the surface of the biocatalyst when immobilize cells are used
MICROORGANISMINVOLVEDIN ETHANOLPRODUCTION Bacteria used: Zymomonas mobilis Clostridium acetobutylicum E.Coli Yeast used Saccharomyces cerevisiae Saccharomyces uvarum Candida utilis Kluyveromyces fragilis
Features of Microbes: Due to the small size, having a high surface ratio. Due to having a resistant cell wall, producing high concentration substances leads to a faster fermentation rate. The intense metabolism permits the development of a continuous fermentation process. Cells growth rate offsets at which cells are removed from the bioreactor. Have the ability to “predigest” the available food source and release both products and the intermediate metabolites. Using immobilized cells of microbes by treating with Calcium alginate to adsorbed on the surface of materials. Using genetically modified microbes to enhance the fermentation process.
Physical requirements: The ideal pH is around 4.0-4.5. The initial temperature is kept between 21-26 ºC. Ethanol gets evaporated at 27 ºC. Aeration is initially required for the growth of microbes. Later, anaerobic condition are created by withdrawing oxygen coupled with the production of carbon dioxide.
Chemical requirements Nitrogen source: Urea is the most suitable source. Gaseous ammonium increases the pH of the medium. Ammonium sulfate can lead to incrustation. Phosphorus source: Diammonium phosphate used as a source. Hydrolytic enzymes They can also be added to convert biopolymers and non- fermentable substances in the molasses to monosaccharides or amino acids
Processflow: Classical fermentation can be achieved in three steps: 1. During the first phase (22-24 h), yeast cells multiply aerobically by consuming oxygen present in the mash. 2. In the middle phase (24-48 h), alcohol production occurs with post saccharification of sugars and multiplication of yeast falls off. 3. The decrease in alcohol formation along with insignificant yeast growth at the final stage (48-72 h).
Production process: There are following steps in ethanol production: 1. Milling 2. Liquefaction 3. Saccharification 4. Fermentation 5. Distillation 6. Dehydration
1. Milling: The feedstock is passed through a hammer mill which grinds it into a fine powder called a meal. 2. Liquefaction: The meal is mixed with water and alpha-amylase. Then passed through cookers where the starch is liquified and heat is applied here to enable liquefaction. Cookers with the high-temperature stage (120-150˚C) and lower temperature holding period (95˚C) are used. High temperatures reduce bacteria levels in the mash
3. Saccharification The mash from the cookers is cooled. And secondary enzyme glucoamylase is added. This converts the liquified starch into the fermentable sugars. 4. Fermentation: Yeast is added to ferment the sugars to ethanol and carbon dioxide. In a continuous process, the fermenting mash can flow through several fermenters until it is fully fermented and leaves the final tank. In a batch process, the mash stays in one fermenter for about 48 hours before distillation starts.
Batch fermentation Yeast reuse results in a decrease in new growth with no more sugar available for ethanol production and an increase in the yield from 2 to 7%.´Traditional yield 1-3g/L. Continuous fermentation: To ensure system homogeneity and reduce the concentration gradient in the culture broth, Continuous Stirrer Tank Reactors are employed. 1) Reduce construction costs of bioreactors 2) Lower requirements of maintenance and operation 3) Better control of the process 4) Higher productivities 5) Cultivation of yeast under anaerobic conditions for a long time diminish their ability to produce ethanol. 6) Aeration is important which can enhance cell concentration
Extraction of the final product: 5. Distillation: Mash is pumped to continuous flow. Multicolumn distillation system where the alcohol is removed from solid and water. The alcohol leaves the top of the final column at about 96% strength. The residue mash is called stillage which is transferred from the base of the column to the co-product processing area. 6. Dehydration: The alcohol from the top of the column is passed through a dehydration system where the remaining water will be removed. Most ethanol plants use a molecular sieve to capture the last bit of water in the ethanol. The alcohol product at this stage is called anhydrous alcohol
Fermentation Byproduct Dried distiller grains with soluble (DDGS): I. The form is available to the feed industry. II. The liquid is separated from mash during the distillation process. III. It is partially dehydrated into syrup. IV. Then added back on to the dried distiller’s grain to create DDGS. Carbon dioxide: I. Used to carbonate the beverages. II. Manufacture dry ice. III. Used to flash freeze meat. IV. Used by paper mills and food industries.
THANK YOU…