ORGANIC SOLVENTS

Ethanol, acetone, butanol, glycerolPetrochemical industries

Due to scarcity of oil and natural gas alternatives for commercial production

Use of low cost raw materials (wood, cellulose, starch)

ALCOHOL

Chemically manufactured by hydration of ethylene (C2H4)In developing countries microbial fermentation is preferred to cheap raw material available.Now other countries also realize the potential due to political and economic analysis.

AS A MOTOR FUEL

Green petrol produced using sugar based plants like sugarcane and cassava. The pioneers are Brazil, with several fermentation and distillation plants the 90% of new cars are run on alcohol as a fuel.

BioAlcohol from Plant Biomass•Fermentation produces alcohol

•Raw materials are 1. STARCHy materials (wheat, rice, maize and potato)2. CELLULOSic material (wood, agricultural wastes)

Brazil: first country to produce ethanol by large scale yeast fermentation by using sugarcane and cassava

Advantages of ethanol as motor fuel:

less envtal. Pollution, 60%less CO2 as compared to petrol, 65% less Hydrocarbon and 15% less nitric oxide

Flash point (temp. at which substance ignites) is higher (45oC) than petrol (13oC)Disadvantages

Costlier than petrolStarting engines in cold difficultEthanol may react with Al and Mg to damage containersShould not pick H2O from air (i.e. highly pure) can cause

corrosion of engines and tanks and will not burn

Gasohol: 20% ethanol (has to be highly pure) and 80% petrol (used in USA)

Ethanol by Fermentation of Micro-organisms

Yeasts: Saccharomyces cerevisae Bacteria: Zymomonas mobilis

Sugary material (molasses, whey, glucose, sucrose)Starchy materials (wheat, rice, maize, potato, cassava)Cellulosic material (wood, agricultural wastes)

Raw material:

Depends on type of raw material.Sugary materials : mild Cellulosic: extensive acidic or enzyme hydrolysis to release monosaccharide unitsPRE TREATMENT: Hydrolysis, clarification, filtration

Pretreatment of raw material:

Milled grain

Gelatinized material

Glucoamylase

Liquefied material

a-amylasecool

Saccharified material

Fermentation Fructose

Glucose isomerase

Alcohol

Yeast

Bacillus amyloliquefaciens

Industrial production of alcohol and fructose from starch

steam

FERMENTATION

PRE TEATMENT

RAW MATERIAL

RAW MATERIAL

PRETREATMENT

STERLIZATION

FERMENTATION

SEPARATION

DISTILLATION

DEHYDRATION

STILLAGE(wastesconcentration)

USED FOR FUEL,FEED OR FERTILIZER, SCP, METHANOL

ETHANOL FERMENTATIONSTARCH

HydrolysisGLUCOSE

GlycolysisPYRUVATE

pyruvate decarboxylase, TPP,

Mg, - CO2ACETALDEHYDE

Alcohol

dehydrogenase, NADH+H+ETHANOL

Ethanol at high conc inhibits its own synthesisEg. Yeasts at 5% alcohol, growth ceasesZymomonas mobilis tolerate 13%

1g glu to 0.511g ethanol (theory)Pure substrates (glu, lac, suc): 95% conversion rateCorn starch (industrial grade): 90%100g pure glucose: 48.5g of ethanol produced, 46.5g CO2, 3.3g glycerol and 1.3g biomass

MolassespH 4-4.521-26oC---30oCO2 initiallyAnaerobic conditions after CO2 produced

Biofuel is defined as solid, liquid or gas fuel derived from recently dead biological material and is distinguished from fossil fuels, which are derived from long dead biological material. Theoretically, biofuels can be produced from any (biological) carbon source

Biofuel

Two common strategies of producing biofuels

One is to grow crops high in sugar (sugar cane, sugar beet, and sweet sorghum) or starch (corn/maize), and then use yeast fermentation to produce ethyl alcohol (ethanol).

The second is to grow plants that contain high amounts of vegetable oil, such as oil palm, soybean, algae, or jatropha. When these oils are heated, their viscosity is reduced, and they can be burned directly in a diesel engine, or they can be chemically processed to produce fuels such as biodiesel. Wood and its byproducts can also be converted into biofuels such as woodgas, methanol or ethanol fuel. It is also possible to make cellulosic ethanol from non-edible plant parts, but this can be difficult to accomplish economically.

Corn, switchgrass, and soybeans, primarily in the United States; rapeseed, wheat and sugar beet primarily in Europe;

sugar cane in Brazil; palm oil and miscanthus in South-East Asia;

sorghum and cassava in China; jatropha in India.

Hemp has also been proven to work as a biofuel.

Biodegradable outputs from industry, agriculture, forestry and households can be used for biofuel production, either using anaerobic digestion to produce biogas, or using second generation biofuels; examples include straw, timber, manure, rice husks, sewage, and food waste.

Biomass can come from waste plant material. The use of biomass fuels can therefore contribute to waste management as well as fuel security and help to prevent climate change, though alone they are not a comprehensive solution to these problems.

Agricultural products specifically grown for biofuel

Bioethanol

Can be used as a replacement to petrol for automobiles

1930s in USA ethanol was produced from maize at 20% conc to produce gasohol called AGROL

In UK gasoholwas markted by Cleaveland Oil Company undr name DISCOL till 1960s until petrol became available and cheaper.

Large scale production was started in 1975 in Brazil follwed by USA in 1978

Ethanol producing microorganisms

Saccharomyces cerevisiae

S. carlsbergensis

Kluyeromyces fragilis

Candida tropicalis

Zymomonas mobilis

Clostridium thermocellum

Yeast

Bact

eri

a

Glucose

Pyruvate

Acetaldehyde

CO2

TCA cycle

Ethanol

NADH NAD+

Glycolysis

Vegetable oil Plant with sugar(sugarcane)

Plant with starch(maize, potato, cassava)

Plant with ligno-cellulose

PURIFIED OIL

Synthetic catalysis

Gasification Hydrolysis

treatment

DehydrationEsterification

BIODIESEL BIOMETHANOLBIOETHANOL

Bioethanol from LignoCellulosic waste

ACETONE AND BUTANOLClostridium acetobutylicumC. butyricum

Glucose

Pyruvate

Acetyl CoA

Acetyl PO4

Acetic acid

Acetoacetyl CoA

b-hydroxybutyl CoA

Crotonyl CoA

Butyryl CoAButyric Acid

Butanol

b-hydroxy-b-methyl glutaryl CoA

Acetoacetic acid

Acetone

Isopropanol

Acetyl COA

Acetyl COA

Acetyl COA

Acetone used in manufacture of nitrocellulose for explosives

Nowadays acetone and butanol are by products of petroleum industryFermentation is discontinued

wood hydrolysates, molasses, starch, sucrose

Phase I: rapid growth, acetic acid, butyric acid, titratable acidity, pH5.2

Phase II: incr in acetone, butanol decr in acidity (acid break)

Phase III: decr in solvent production and no incr in pH

Contamination: absolute sterile conditions are required, bacteriophages and Lactobacilli cn be contaminants

Product yield: 30% carbohyd. Gets converted. With molasses 7:3 butane acetone and corn medium 6:3. Production of butanol is influened by its toxicity…more than 13.5% conc is toxic.

Recovery: acetone and butanol recovered by continuous distillation and fractionation. Leftover residue is used as animal feed after drying.

PRODUCTIONRaw material: molasses, ammonium sulphate, Ca CO3, corn steep liquor, gassed with CO2, starting pH 5.8-6.0, 34oC, 36h

GLYCEROL

• Starting material for manufacture of explosives

• Produced by saponification of fats and oils.

• Chemically synthesized from propylene or propane

PRODUCTION Produced by yeast during alcoholic fermentationSodium bisulfite blocks blocks alcohol production and large scale glycerol production

Glucose

Fructose 1,6 bisPO4

Glyald 3 PO4

Pyruvate

Acetaldehyde

Ethanol

Sodium bisulfite blocks

DHAPO4

Glyald 3 PO4

GLYCEROL

DHAPdehydrogenase

CH2-OH

CH-OH

CH2-OH

ACETALD. SULFITE COMPLEX

Sodium sulfite +CO2 ---> Sod bisulfite

2-3 days50% yield

PRODUCTION from alga and bacteria

Dunalielia salina in Israel, lives in high salt envt and synthesizes glycerol to balance osmotic pressure of hypersaline lakes.

When surrounding salt is more more intracellular solutes (glycerol)When surrounding salt conc is reduced, glycerol is exxcreted out into medium

Bacillus subtilis capable of converting glucose to glycerol, ethanol,Lactic acid, butanediolProduces high yield at anaerobic conditions despite being an aerobic MO