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ACETIC ACID
Made By:Ravi Shankar AzadSreedharSharathShubham
INDEX
Flow Chart Raw Materials and Microbes Processes Used Reactors Used Present Technologies
FLOW CHART FOR ACETIC ACID FORMATION
Biomass feedstock + Acetobactor
xylinum
Fermentation
Acetic Acid + By-Products
PurificationPure Acetic Acid
RAW MATERIALSo Biomass Feedstock ( wood chips, green crops, manure, farm
and mill waste)o Cooked Grapes
o Genus Acetobacterium commonly used- Acetobacterium aceti Acetobactor xylinumo Acetic Acid Bacteria (fruit flies and vinegar eels propagate
AAB in nature)o Genus Clostridium commonly used- Clostridium thermoaceticum-anerobic
thermophile
MICROBES
COMPARISON
AAB Acetobacterium Clostridium
Gram-negative Gram-positive Gram-positiveaerobic anaerobic thermophillicOxygen is required No oxygen
requiredOxygen is required
Acid tolerant upto pH 2.5
Acid tolerant upto pH 5
Less acid tolerant
Different microbes are used in different processes discussed later
As Clostridium is thermophilic it reduces cooling costs
REACTORS USED Batch Fermentor –converts sugars to acetic
acid Uses Clostridium thermoaceticum Fluidized bed bioreactor(3 phase) –uses
Acetobacter aceti Silicon Tube reactor- Uses Acetobacter aceti Series Batch reactor- Uses Acetic Acid
Bacteria
DIFFERENT PROCESSES USED
By Acetic Acid Bacteria in Series batch reactor
By Acetobacter aceti in a silicone tube reactor
pH controlled batch fermentation Oxidative fermentation Anaerobic fermentation
BY ACETIC ACID BACTERIA IN SERIES BATCH REACTOR Raws materials- cooked grapes having a content of
soluble solids Microbes-Acetic Acid Bacteria pH range-2.5 to 3.2 Temperature – 200C to 300C Pressure- 1 atm Max conc. of Acetic Acid- 12g/lit Oxygen requirement- optimum concentration of 1-3
mg/kg of AAB Produces TBV from glucose and then converts TBV to Acetic acid
SCHEMATIC PROCESS OF FORMATION OF TBV(TRADITIONAL BALSAMIC VINEGAR)
BY ACETOBACTER ACETI IN A SILICONE TUBE REACTOR Materials and microbes- Acetobacter aceti grown on a
liquid surface of a shallow flow reactor . Medium- glucose, peptone, yeast extract. Reactor- Silicone tube batch reactor contains 20-40 silicone
tubes Dilution rate- 0.3 /h Temperature 270C Max concentration of Acetic Acid 47.3 g/lit with residence
time of 2.5 hr Oxygen required – residence time 2.5 hr Reaction C2H5OH + O2 → CH3COOH + H2O
PH CONTROLLED BATCH FERMENTATION Materials and microbes used- Clostridium thermoaceticum
derived from parent culture wood (wild type) pH conditions- 6 and 7 Dilution rate -0.1 /h Obtained Acetic Acid Concentration- 5 g/litre Reactor- Batch Fermentor (no oxygen required) Temperatue – 25-280 C Pressure – 1.5 atm Reaction C6H12O6 → 3 CH3COOH
Redox Potential Condition- -300 mV Max. Conc reached- 15 and 20 g/lit at pH 6 and 7 respectively
FERMENTOR
OXIDATIVE FERMENTATION BY MONSANTO PROCESS• Given sufficient oxygen, these bacteria can produce
vinegar from a variety of alcoholic foodstuffs. Commonly used feeds include apple cider, wine, and fermented grain, malt, rice, or potato mashes. The overall chemical reaction facilitated by these bacteria is:
C2H5OH + O2 → CH3COOH + H2O
A dilute alcohol solution inoculated with Acetobacter and kept in a warm, airy place will become vinegar over the course of a few months. Industrial vinegar-making methods accelerate this process by improving the supply of oxygen to the bacteria.
• One of the first modern commercial processes was the "fast method" or "German method", first practiced in Germany in 1823. In this process, fermentation takes place in a tower packed with wood shavings or charcoal. The alcohol-containing feed is trickled into the top of the tower, and fresh air supplied from the bottom by either natural or forced convection. The improved air supply in this process cut the time to prepare vinegar from months to weeks.
• The production of acetic acid by the Monsanto process utilises a rhodium catalyst and operates at a pressure of 30 to 60 atmospheres and at temperatures of 150 to 200°C. The process gives selectivity of over 99 per cent for the major feed-stock ethanol
THE MAJOR UNITS COMPRISING A COMMERCIAL-SCALE MONSANTO METHANOL OPERATING PLANT, WHICH USES A RHODIUM BASED CATALYST. THE TECHNOLOGY USES THREE DISTILLATION COLUMNS TO SEQUENTIALLY REMOVE LOW BOILERS (METHYL IODIDE AND ETHYL ACETATE). WATER; AND HIGH BOILERS (PROPIONIC ACID) AND DELIVER HIGH PURITY ACETIC ACID PRODUCT
PRESENT TECHNOLOGIES
o ACEO bio-acetic acid pilot plant in Burghausen has already been up and running for the past six months and uses following processes. ACEO Process - involves a biomass feedstock being converted to ethanol (using yeast) and producing acetic acid via gas phase oxidation process
o Fermentation to Butanediol - Ferments biomass feedstock using bacteria to butane 2,3 diol, which could be then dehydrated to produce methyl ethyl ketone (MEK) or directly produce acetic acid via gas phase oxidation. Acetic acid from MEK is also possible via gas phase oxidation.
o Homoacetate Fermentation - Ferments biomass feedstock to acetate/acetic acid using bacteria.
WACKER ACEO PROCESS
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