BIOCONVERSION TECHNOLOGIES PTT203 BIOCHEMICAL ENGINEERING PUAN NURUL AIN HARMIZA ABDULLAH
Introduction: BIOCONVERSION Sugarcane residue Coconut residue ABUNDANCE OF BIOMASS WHOLE OVER THE WORLD Empty fruit bunch residue Impose environmental problems
What is Biomass • Living and dead biological material that can be used for biofuel or industrial production. Focus on biomass produced from agriculture activities.
How to use the biomass? Convert to useful products . 1. Convert to energy . 2.
Products from bioconversion • Industrial chemicals (organic acids, acetic acids, biopolymers) • Food additives (amino acids, nucleosides, vitamins, fats and oils) • Health care products (antibiotics, steroid, vaccines, monoclonal antibodies) • Industrial enzymes (amylases, proteases, hydrolases).
Energy from biomass Biofuels • Bioethanol – made from crops eg: sugarcane, corn, potato. • Biodiesel – made from oils/fats using transesterification process • Biogas (methane, CO 2 , N 2 ) – produce by the biological breakdown of organic matters in the absence of O 2
What method can we use? • Physically? • Chemically? • Biologically?
Physical Method • Mechanical processes; • Eg: pelletization of wood waste, paddy straw. • Extraction process
Thermo chemical methods • A process where heat is the dominant mechanism to convert biomass into another chemical form. • Three different classes of thermo chemical: Combustion/burning 1. Gasification – convert carbonaceous 2. materials into carbon monoxide&hydrogen (syngas) Liquefaction 3.
Biological methods • Use of the enzymes of bacteria and other micro-organisms to break down biomass. • Micro-organisms are used to perform the conversion process: anaerobic digestion, fermentation and composting. • The importance group of bacteria in bioconversion are: Lactic acid bacteria 1. Acetic acid bacteria 2. Bacteria of alkaline fermentation 3.
What is bioconversion • Bioconversion is the conversion of organic materials, such as plant or animal waste, into usable products or energy sources by biological processes or agents, such as certain microorganisms or enzymes. • Things to consider: What to convert 1. What to use 2. What to get 3.
What bioconversion can do • Bioconversion can be carried out physically, thermochemically and biologically. • This process has been applied in the production of foodstuffs, organic chemicals and energy. • Biological methods for bioconversion has given priority with the use of microorganisms as less expensive yet effective agents. • This process is also known as fermentation.
BIOCONVERSION TECHNOLOGY FOR ACETIC ACID PRODUCTION
Acetic acid • CH 3 COOH, also known as ethanoic acid. • Is an organic acid that gives vinegar its sour taste and pungent smell. • Acetic acid is one of the simplest carboxylic acids. • Commercial production of acetic acid is often accomplished by a chemical reaction of methanol and carbon monoxide (with catalyst). • Usage : • in vinegar making (4%-18% acetic acid). • Solvent. • cellulose acetate used in photographic film.
Acetic acid production • Microorganism used : Acetobacter - Is a genus of acetic acid bacteria. - Have the ability to convert ethanol to acetic acid in the presence of oxygen. - They are Gram-negative, Aerobic, and Rod-shaped bacteria.
• Type of culture : Highly aerated fermentation. • Raw material : Diluted purified ethanol from grape juice, apple juice, barley malt etc. • Acetic acid fermentation: • Acetobacter convert alcohol to acetic acid in the presence of excess oxygen. • The oxidation of one mole of ethanol yields one mole each of acetic acid and water; • C 2 H 5 OH + O 2 → CH 3 COOH + H 2 O S.cerevisiae Acetobacter Anaerobic Aerobic
Production of Vinegar/Acetic acid
Factors influence acetic acid production Factors influence - Oxygen supply and the concentration gradients of ethanol and acetate. 1.Lack of oxygen • lack of O 2 will killed the bacteria because they are extremely sensitive. • To overcome this problem, has to use efficient aeration • Efficient aeration can be achieved with the used of compressed air and proper mechanical device. • For efficient aeration also have to consider shear stress imparted by the fluid and the microorganisms itself. • The efficiency depends on the ratio between the energy input necessary per unit weight of O2 transferred to the culture.
• 2.Over-oxidation • When there is over-oxidation, acetic acid will convert to CO2 and H2O. • Will decrease acetic acid production. • Have to maintain acetic acid concentrations above 6% of the total culture and avoid the total depletion of ethanol.
BIOCONVERSION TECHNOLOGY FOR CITRIC ACID PRODUCTION
Citric acid • Is a weak organic acid C 6 H 8 O 7 . • Exists in greater than trace amounts in a variety of fruits and vegetables, most notably citrus fruits. • Commercial citric acid is produced by fermentation of carbohydrates or citrus juices. • Usage : - to add an acidic or sour taste to foods and soft drinks. - general additive in the confectionery industry. - pharmaceutical industries
Citric acid production • Microorganism used : Aspergillus niger or Candida sp. (yeast) • Culture method : submerged fermentation system and surface fermentation • Raw materials : Molasses, sugarcane syrup, sucrose
• Biochemistry of production (Involves few steps) Breakdown of hexoses (sugar) to pyruvate and acetyl CoA. 1. The anaplerotic formation of oxaloacetate from pyruvate and 2. CO 2 The accumulation of citrate within the tricarboxylic acid cycle 3. - The key enzyme is pyruvate carboxylase , constitutively produced in Aspergillus species.
Factor influence citric acid production using submerged culture method. sensitive to iron. Medium used must be iron-deficient. Fermentor must be stainless steel to prevent leaching of iron from fermentor wall Oxygen supply pH should maintain below 2.0. At higher values, A.niger accumulates gluconic acid rather than citrate.
Ethanol production
Bioconversion technology for ethanol production • Ethanol or ethyl alcohol (C 2 H 5 OH) is a clear colourless liquid, it is biodegradable, low in toxicity and causes little environmental pollution if spilt. • Ethanol burns to produce carbon dioxide and water. • Ethanol is widely used in Brazil and in the United States. • Most cars on the road today in the U.S. can run on blends of up to 10% ethanol and 90% petrol • Application of ethanol : raw material, solvent, used in fuel and in chemical, pharmaceutical & food industries.
• Bioethanol, unlike petroleum, is a form of renewable energy that can be produced from agricultural feedstocks. • It can be made from very common crops such as sugar cane, potato, manioc and maize.
Basic biology and technological method - biologically, alcohol was formed when there is an action of microorganisms in the form of yeast anaerobs on sugar or carbon containing solution. sugar + yeast ethanol + carbon dioxide C 6 H 12 O 6 + yeast 2C 2 H 5 OH + 2CO 2 - For commercialization of ethanol production, two different types of substrates are available for fermentation. - Both substrates need different type of pre-treatment. 1. Sugar containing biomass 2. Starch containing biomass
Bioethanol production Substrate : Sugar containing biomass
• Sugar containing biomass : sugar cane, molasses, sugar beet • Production steps : 1. milling/grinding (extract juices) 2. fermentation of juices (sugar) with yeast sugar + yeast ethanol + carbon dioxide C6H12O6 + yeast 2C2H5OH + 2CO2 3. Distillation 4. Dehydration
Bioethanol production Substrate : Starch containing biomass
• Starch containing biomass : maize, cassava, grain, potato • Production steps : 1.Slurry preparation • The starch-containing substrate (Cassava powder) is mixed with water to form slurry. 2.Gelatinization • The slurry is then gelatinized with steam (68-74°C). Gelatinization is the formation of starch paste.
3.Dextrinization • Dextrinization is the breakdown of gelatinized starch into smaller fragments or dextrins by means of α - or Β -amylase. The action of α -amylase on gelatinized starch results in dramatic reduction of viscosity. 4.Saccharification • Saccharification is the complete conversion of dextrins into glucose (sugar) through the action of glucoamylase. 5.Fermentation • The resulting sugar is cooled and transferred to a fermentor where yeast is added. It is catalyzed by the action of enzymes present in microorganisms like yeasts with ethyl alcohol as the end product. sugar + yeast ethanol + carbon dioxide C6H12O6 + yeast 2C2H5OH + 2CO2
Recommend
More recommend
