BIOCONVERSION TECHNOLOGIES PTT203 BIOCHEMICAL ENGINEERING PUAN - - PowerPoint PPT Presentation

BIOCONVERSION TECHNOLOGIES

PUAN NURUL AIN HARMIZA ABDULLAH

PTT203 BIOCHEMICAL ENGINEERING

Introduction: BIOCONVERSION

ABUNDANCE OF BIOMASS WHOLE OVER THE WORLD Sugarcane residue Impose environmental problems Empty fruit bunch residue Coconut residue

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?

1.

Convert to useful products.

2.

Convert to energy.

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
• ils/fats using

transesterification process

• Biogas (methane, CO2, N2) –

produce by the biological breakdown of organic matters in the absence of O2

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:

1.

Combustion/burning

2.

Gasification – convert carbonaceous materials into carbon monoxide&hydrogen (syngas)

3.

Liquefaction

Biological methods

• Use of the enzymes of bacteria and
• ther 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:

1.

Lactic acid bacteria

2.

Acetic acid bacteria

3.

Bacteria of alkaline fermentation

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:

1.

What to convert

2.

What to use

3.

What to get

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

• CH3COOH, 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
• xygen.
• The oxidation of one mole of ethanol yields one mole each of acetic

acid and water;

• C2H5OH + O2 → CH3COOH + H2O

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 O2 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%
• f the total culture and avoid the total depletion of

ethanol.

BIOCONVERSION TECHNOLOGY FOR CITRIC ACID PRODUCTION

Citric acid

• Is a weak organic acid C6H8O7 .
• 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)

1.

Breakdown of hexoses (sugar) to pyruvate and acetyl CoA.

2.

The anaplerotic formation of oxaloacetate from pyruvate and CO2

3.

The accumulation of citrate within the tricarboxylic acid cycle

• 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 (C2H5OH) 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 C6H12O6 + yeast 2C2H5OH + 2CO2

• 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

6.Distillation

• After fermentation, the fermented liquor is transferred to a

distillation process where the ethanol is separated from the remaining stillage (residue non-fermentable solids and water). Distillation is the process in which a liquid or vapor mixture of two or more substances is separated into its component fractions of desired purity by the application or removal of heat. This process can usually produce a 95.6% by volume ethanol product. 7.Dehydration

• Ethanol from distillation process is sent to the molecular

sieves column for further dehydration to produce 99.7% v/v ethanol.

Bioethanol production Substrate : cellulose containing biomass

• cellulose containing biomass : paddy straw, wood,

coconut husk, paper waste

• Production steps :
• 1. biomass harvested
• 2. biomass pretreatment with heat or chemicals (NaOH,

HCL) - Cellulose is a polymer of glucose. Hemicellulose is a copolymer of different

C5 and C6 sugars including e.g. xylose, mannose and glucose, depending on the type

• f biomass. Lignin is a branched polymer of aromatic compounds.

• 3. Hydrolysis of cellulose with enzyme nto

produce sugar

• 4. Fermentation of sugar with yeast

sugar + yeast ethanol + carbon dioxide C6H12O6 + yeast 2C2H5OH + 2CO2

• 5. Distillation

After fermentation, the fermented liquor is transferred to a distillation process where the ethanol is separated from the remaining stillage (residue non-fermentable solids and water).

Biodiesel production

Biodiesel

• Biodiesel refers to a vegetable oil- or animal fat-

based diesel fuel consisting of long-chain alkyl (methyl, propyl or ethyl) esters.

• Biodiesel is typically made by chemically reacting

lipids (e.g., vegetable oil, animal fat, soybean, palm oil, jathropa, sunflower oil, canola) with an alcohol.

• Biodiesel can be used in pure form or may be

blended with petroleum diesel at any concentration in most injection pump diesel engines.

• Biodiesel is a light to dark yellow liquid.
• It is practically immiscible with water, has a high boiling

point and low vapor pressure.

• Biodiesel is a renewable fuel that can be manufactured

from algae, vegetable oils, animal fats or recycled restaurant greases; it can be produced locally in most countries.

• It is safe, biodegradable and reduces air pollutants, such

as particulates, carbon monoxide and hydrocarbons.

• Blends of 20 percent biodiesel with 80 percent petroleum

diesel (B20) can generally be used in unmodified diesel engines.

• Biodiesel can also be used in its pure form (B100), but

may require certain engine modifications to avoid maintenance and performance problems.

Biodiesel production

• Biodiesel production is the act of producing the

biodiesel, through either transesterification or alcoholysis. The process involves reacting vegetable oils or animal fats catalytically with a short-chain aliphatic alcohols (typically methanol or ethanol).

• Production steps : biodiesel from soybean seeds
• 1. Raw materials screening

Remove impurities/dirts from raw materials

• 2. Oil extraction

Extract oil by pressing or using solvent extraction

• 3. Purification

Remove impurities from the oil (centrifuge)

• 4. transesterification

Reaction of oil with methanol+catalyst (NaOH, HCl, lipase)+heat. Will produce methyl ester and Glycerol

Transesterification

• 5. Purification

a) Separation of methyl ester with glycerine. Glycerine more dense than methyl ester. So glycerine will settle at the bottom. b)Wash biodiesel with water to remove contaminants. Water is heavier than biodiesel and absorb excess methanol+NaOH

Advantages of bioconversion

• Increase recycling
• generate money from waste
• Generation of renewable energy
• bioethanol..biodiesel..biogas
• not too dependent on fossil fuel
• Reduce landfill effect
• It saves space in landfills.
• Offset to fossil fuel usage
• expand energy freedom of choice.
• Reduce carbon emission
• reduce greenhouse gasses by using bioenergy

• Remediate ecological disaster
• Municipal solid wastes – is getting out of control

necessitating bigger landfills that are further away from

• ur urban centers. This excess waste contributes to

land, water, and air pollution

Convert solar energy into liquid fuels

Reduce Greenhouse Gases

Please read article entitle “Carbon’s New Math” to get full picture on this Advantages.

Remediate ecological disaster

• 1. Municipal solid wastes – is getting out of

control necessitating bigger landfills that are further away from our urban centers. This excess waste contributes to land, water, and air pollution

• 2. Rural agricultural residues and damaged crops

could have a higher value as soil amendments and biomass feedstock