Annual growth of 10,000 tons of anhydrous ethanol production process and equipment program Abstract Keywords Fuel ethanol Production process Material accounting Equipment selection Body 1, Preface Anhydrous ethanol is a very widely used organic solvent, which is a renewable bioenergy. Among them, fuel ethanol is considered to be one of the best raw materials to replace and save gasoline, and can be mixed with gasoline in a certain ratio to form a kind of automotive raw material. Ethanol can be produced by chemical synthesis and bio-fermentation. With the global shrinkage of petroleum, chemical synthesis has been limited, and bio-fermentation production of ethanol is respected and applied by all parties. Bio-fermentation is a method that utilizes starchy or sugary raw materials to produce ethanol under the action of microorganisms. Starchy raw materials to produce ethanol process includes: raw material crushing, cooking saccharification, masterbatch preparation, fermentation and distillation refining and other processes. 2, fuel ethanol 2.1 ethanol nature Alcohol is a colorless and transparent, volatile, easy to burn, non-conductive liquid. There is the smell of wine and stimulating pungent taste, slightly sweet. The scientific name is ethanol, the molecular formula C2H6O, (alcohol combustion C2H5OH + 3O2 = 2CO2 ↑ + 3H2O) because of its chemical molecular formula contains hydroxyl, so it is called ethanol, specific gravity 0.7893 (20 / 4 °). Molecular weight of ethanol: 46

Appearance and properties: colorless liquid with wine aroma.

Flammability: 75 ℃ Melting point: -114.1 ℃ Boiling point (a standard atmospheric pressure): 78.3 ℃

Relative density (water = 1): 0.79 Relative vapor density (air = 1): 1.59 Saturated vapor pressure (kPa): 5.33 (19 ℃)

Heat of combustion (kJ/mol): 1365.5

Critical temperature (℃): 1.5 ℃. Critical Temperature(℃): 243.1 Critical Pressure(MPa): 6.38

Logarithmic value of octanol/water partition coefficient: 0.32 Flash Point(℃): 12

Initiation Temperature(℃): 363

Upper Explosion Limit %(V/V): 19.0 Lower Explosion Limit %(V/V): 3.3 2.3 2.2 Classes and Main Products Industrial Ethanol (the product is fuel ethanol) Industrial Ethanol (the program) product is fuel ethanol) Industrial alcohol contains more than 96% ethanol and a small amount of methanol and other substances. Methanol is harmful. It is volatile and harmful to the respiratory system. Some people use industrial alcohol (ethanol with methanol) to make wine, which can cause blindness when consumed. Edible Ethanol: Edible alcohol is obtained by filtering and distillation after fermentation using grain and yeast in fermentation tanks. It is usually an aqueous solution of ethanol, or a mutual soluble body of water and ethanol, and does not contain benzene and methanol, which are toxic to humans. Pharmaceutical ethanol: the ethanol content is around 75% Anhydrous ethanol: anhydrous ethanol has a very high alcohol content and is divided into chemically pure and analytically pure, with chemically pure content greater than or equal to 99.5%, and analytically pure content above 99.9%. Fuel ethanol is anhydrous ethanol without denaturant that can be used as fuel. Fuel ethanol can alleviate energy constraints, reduce environmental pollution, and promote agricultural development. 3, the production process 3.1 General Process Dual enzyme saccharification intermittent (or continuous) hair teach alcohol process schematic a-amylase saccharification enzyme ↓ ↓ dried potatoes → crusher → mixing tank → continuous digester → cooking mash → saccharification pot waste tank ↓ alcohol ← molecular sieve dehydration ← distillation ← mature fermentation mash ← fermentation mash ← saccharification mash mash heteroalcohol oil ↙ ↙ ↙ ↙ ← ↓ Water: including powder liquefaction saccharification water, fermentation water, distillation plant water and cleaning water, etc., all using city tap water or tap water after a series of sterilization and disinfection of sterile water. Amylase and saccharification enzyme: a-amylase dosage is 8u/g raw material, saccharification enzyme dosage is 100u/g raw material, and saccharification enzyme dosage for mother liquor saccharification mash is 200u/g raw material. Sulfuric acid and ammonium sulfate, etc.: Ammonium sulfate dosage is 8kg/t (for alcohol), and sulfuric acid dosage (for pH adjustment) is 5.5kg/t (for alcohol). Ethanol yeast: strain for fermentation, which will ferment the saccharification mash to produce ethanol, CO2 and other by-products.3.2.2 Raw material pretreatment Schematic diagram of dried potatoes pretreatment Raw material dried potatoes → Screening → Flotation → Magnetic Separation → Crushing → Pulping → Liquefaction (Pasteurization) ↓ ↓ ? ? ? ↓ Fibers, silt, stones, bricks Iron impurities Molasses ← Cooling ↑ Molasses enzymes 3.2.2.1 Removal of impurities from the raw materials and pulverization (1) Starchy raw materials are collected when they will be mixed into sand, dirt, debris, and even metal inclusions. Generally used first vibrating screen screening, and then magnetic iron separator magnetic separation to remove impurities. (2) starch raw materials in the starch granules are often stored in the cell in a granular state, should not be directly utilized. After crushing is conducive to increasing the surface area of raw materials, speed up the water absorption rate, shorten the time of hydrothermal treatment; amylase is conducive to the role of amylopectin, improve the conversion rate of starch, and at the same time is conducive to the transportation of raw materials in the production process. Crushing methods include dry crushing and wet crushing, and this time the wet crushing is used for production (3) The starch loss rate caused by dust loss is about 0.40%.3.2.2 Hydrothermal treatment (liquefaction) and continuous cooking and saccharification (1) Liquefaction of starch: it is the process of using starch liquefaction enzyme to make the viscosity of pasted starch lower and hydrolyze it into dextrin and oligosaccharides. Using high-temperature-resistant a-amylase, a processing temperature of 95℃ is used, and using ordinary a-amylase, a processing temperature of 85℃ is used. A low-pressure jet liquefier is now used to complete the liquefaction of starch. The temperature of the slurry is 50 ℃, the jet liquefier makes the slurry rapidly warm up to 105 ℃, enter into the maintenance pipe to keep warm and liquefy for 5~8min, the vacuum flash evaporates and cools down to 95 ℃ to enter into the liquefaction tank to react for about 60min, and then enter into the vacuum cooler to cool down to 63 ℃ and then saccharify for 30min. low-pressure jet liquefaction process Powder → water slurry → jet liquefaction → keep warm and liquefy → cool and saccharify ↑ ↑ a-amylase Steam (2) Saccharification of starch: It is the process of further hydrolyzing the product of starch liquefaction into glucose by using saccharification enzymes, and providing the mash with the right amount of sugar for fermentation and maintaining a certain enzyme vitality, which is free of bacteria or has very few stray bacteria. The temperature of saccharification is generally controlled according to the optimal action temperature of saccharification enzyme, i.e. 58~60℃, and the optimal pH of saccharification enzyme action is 4.2~5.0. The pH of mash is too high or too low, which will destroy enzyme vitality, and is not conducive to saccharification. The dosage of saccharification enzyme is generally 80~150U per gram of starch, depending on the variety of raw materials, saccharification method and other quantitative. The saccharification time should not be too long, generally in the range of 15~25min, can also be adjusted according to the saccharification mash, that is, to produce 25%~35% of the reducing sugar time is appropriate. (1) Original strain slant culture: wort agar, 25~30℃ for 3~5 days (keep at 4℃ in the refrigerator for spare use). (2) Liquid test tube: 10°Bx wort, sterilized and cooled to 25~30℃, aseptically inoculated and set at 25~30℃ for 20h. (3) Triangle bottle culture: 1/3 wort and 2/3 saccharification mash, 25~30℃ for 12~14h, pH4~6 (4) Cassette tank culture: saccharification mash, 25~30℃ for 12~14h, pH4~6 (5) Small mother of wine tank, Large mother tank culture: saccharification mash, 25~30℃ culture 12~14h, pH4~63.3 Ethanol fermentation - strain: ethanol yeast; medium: dried potato saccharification mash→fermentation mash; pH:4.2~4.5; (1) Pre-fermentation period: the density of the yeast in the mash is small, and the yeast carries on adaptation, and the fermentation is not strong. In actual production, the amount of mother liquor is around 10%, and the duration of pre-fermentation period is 6~8h. In continuous fermentation, the pre-fermentation period is basically non-existent. (2) Main fermentation period: The yeast no longer reproduces in large quantities, but mainly carries out ethanol fermentation, with strong fermentation, rapid sugar consumption and gradual increase of ethanol. The main fermentation temperature is controlled at 30~34℃, not higher than 34~35℃, and the fermentation time is generally 12~15 hours. (3) Post-fermentation period: most of the sugar in the mash has been fermented, but the residual dextrin and other polysaccharide components in the mash continue to be converted into fermentable sugar, which the yeast converts into ethanol. The rate of post-fermentation is much slower than the rate of sugar fermentation, ethanol and CO2 production is reduced, and it appears that bubbles continue to be produced, but the mash is no longer turned over. The post-fermentation period generally takes about 40 hours to complete, keeping the mash temperature at 30°C ± 1°C . (4) Starch loss rate during fermentation: fermentation residual sugar - 1.3% Pasteur effect - 4.0% Natural evaporation of alcohol gas and carried away by CO2 - 0.30% ( If there is an alcohol trap, the loss of 0.30%) 3.4 Separation and purification and distillation refining separation and purification process flow chart fermentation tank → pump → mash tower → concentration tower → crude alcohol → molecular sieve tower A, B → condensation ↑ ↓ steam steam anhydrous ethanol process of starch loss rate: (1) waste tanks to take away, etc. - 1.60%

(2) dehydration loss - 1.0% 3.5 by-product utilization and wastewater sludge treatment alcohol tank → solid-liquid separation → filtrate → treatment → clarified liquid → reuse and biological treatment ↓ ↓ ↓ ↓ filtration slag → feed ← slurry 4, material accounting (1) production methods: double enzyme saccharification, batch fermentation, tower distillation. (2) Production days: 300d per year. (3) Daily output of fuel alcohol: 344t. (4) Annual output of fuel alcohol: 100200t. (5) Product quality: International Fuel Alcohol, ethanol content of 99.5% or more (v/v) (6) Main raw materials: dried potato raw material containing 68% starch, 13% moisture. (7) Enzyme dosage: a-amylase dosage of 8u/g raw materials, saccharification enzyme dosage of 100u/g raw materials, mother liquor saccharification mash with saccharification enzyme amount of 200u/g raw materials. (8) Ammonium sulfate dosage 8kg/t (alcohol), sulfuric acid dosage (for pH adjustment) 5.5kg/t (alcohol). A raw material calculation ① saccharification: (C6H12O5) n + nH2O → n C6H12O6 (1-1) 162 18 180 fermentation: C6H12O6 → 2 C2H5OH + 2CO2 (1-2) 180 46 × 2 44 × 2 ② production of 1000kg of fuel alcohol by the theoretical starch consumption of (1-1) and (1-2) to find the amount of: 1000 × 99.18% × 162 ÷ 92 = 1746.5 (kg) The fuel alcohol volume fraction of 99.5% is converted to a mass fraction of 99.18%. ③ production of 1000kg fuel alcohol the actual starch consumption Table (3-1) production process stages of starch loss rate production process loss reasons starch loss rate % Remarks raw material handling dust loss 0.40 cooking saccharification starch residue and sugar bad 0.40 fermentation fermentation residual sugar 1.3 fermentation Pasteur effect 4.0 fermentation wine gas natural evaporation and be taken away by the CO2 0.30 plus alcohol traps 0.30% distillation waste tanks, etc. 1.60 dehydration dehydration loss 1.0 Total loss 9.01746.5 ÷ (100% - 9.0%) = 1919.2 (kg) ④ production of 1,000 kg of fuel alcohol dried potato raw material consumption dried potato raw material containing 68% starch, water 13% 1919.2 ÷ 68% = 2822.4 (kg) (5) Consumption of a-amylase, with enzyme activity of 20,000 u/g: 2822.4×1000×8÷20,000=1.29 (kg) (6) Consumption of saccharase, with enzyme activity of 100,000 u/g: 2822.4×1000×100÷100,000=2.82 (kg) In addition, the saccharification enzyme dosage of brewer's mother is 200u/g (raw material), and the dosage of brewer's mother is 10% 2822.4 × 10% × 70% × 200 ÷ 100000 = 0.395 (kg) where 70% of the formula is 70% of the saccharification solution of brewer's mother. The rest is dilution water and saccharification agent. The total of the two items, the amount of saccharification enzyme is 3.215kg. ⑦ Ammonium sulfate consumption as a supplementary nitrogen source, the amount of which is 0.1% of the amount of mother liquor. Second, the calculation of cooking mash amount of starch raw materials continuous cooking powder and water for 1:2, so the amount of powder pulp: 2822.4 × (1 + 2) = 8467.2 (kg) by jet liquefaction continuous cooking, the final cooking mash amount of 8597.4 kg. Third, the calculation of saccharification mash and fermentation mash amount of mature mash after the end of the fermentation is set to contain 10% (volume fraction) of alcohol, which is equivalent to 8.01% (mass fraction). fraction). And set the distillation efficiency of 98.4%, and the fermenter alcohol trap recovery of alcohol wash water and tank washing water for the mature mash of 5% and 1%, respectively, then the production of 1000kg 99.18% (mass fraction) alcohol finished product is calculated as follows: ① need to distill the amount of mature fermentation mash is: F = 1000 × 99.18% ÷ 98.4% ÷ 8.01% × (100 + 5 + 1) ÷ 100 =13338.4 (kg) ② If not counting the alcohol trap and tank washing water, the amount of mature fermentation mash: 13338.4 ÷ 106% = 12583.4 (kg) ③ into the distillation tower of the mature mash ethanol concentration: 1000 ÷ 98.4% ÷ 13338.4 = 7.62% (mass fraction) ④ corresponding to the total amount of fermentation process CO2 released 991.8 ÷ 98.4% ÷ 44 ÷ 1 ÷ 100 ÷ 100 ÷ 100 98.4% × 44 ÷ 46 = 964.1 (kg) ⑤ Inoculation is calculated as 10%, then the volume of the mother mash is m: (2583.4 + 964.1) ÷ (100 + 10) ÷ 100 × 10% = 1231.6 (kg) ⑥ Seventy percent of the mother mash is the saccharification mash, and the rest is the saccharifying agent and dilution water, then the volume of the saccharification mash is: (2583.4 + 964.1) ÷ ( 100 + 10) ÷ 100 + 1231.6 × 70% = 13178.0 (kg) Fourth, 10,000t / a dried potatoes raw material alcohol plant total material accounting ① Alcohol finished product daily production of fuel alcohol: 10,000 ÷ 300 = 33.3 (t), take the integer 34t / d actual annual total fuel alcohol production: 34 × 300 = 10020 (t / a) ② main Raw material dried potato consumption per day: 2822.4 × 34 = 95961.6 (kg / d) annual consumption of: 95961.6 × 300 = 2.879 × 106 (kg) = 282,885 (t / a) Table (4-1) 10,000t / a dried potato raw material alcohol plant material accounting table material ﹨ Quantity production 1000kg fuel alcohol material quantity / kg per day / t per year / t fuel alcohol 1000kg fuel alcohol material quantity / kg per day / t per year / t fuel alcohol 1000kg fuel alcohol 1000kg fuel alcohol material quantity / kg per day / t per day / t per year / t fuel alcohol 1000kg fuel alcohol 1000kg fuel alcohol t per year quantity/t fuel alcohol 10003410020 dried potato raw materials 2822.495.961628788.48 a-amylase 1.1290.0383911.5158 saccharase 3.2150.1093132.793 ammonium sulfate 1.2320.0418912.5664 sulfuric acid 5.50.18756.1 cooking Pulp 8467.2287.88586365.44Matured cooking mash 8597.4292.31287693.48Saccharification mash 13178448.052134415.6Master mash 1231.641.874412562.32Distilled fermentation mash 13338453.506136051.7Carbon dioxide 964.132.77949833.82Waste mash 13550460.697138209