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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