ORGANIC SOLVENTS. Ethanol, acetone, butanol , glycerol Petrochemical 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)
Ethanol, acetone, butanol, glycerol
Due to scarcity of oil and natural gas alternatives for commercial production
Use of low cost raw materials (wood, cellulose, starch)
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.
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)
Costlier than petrol
Starting engines in cold difficult
Ethanol may react with Al and Mg to damage containers
Should 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)
Yeasts: Saccharomyces cerevisae Bacteria: Zymomonas mobilis
Sugary material (molasses, whey, glucose, sucrose)
Starchy materials (wheat, rice, maize, potato, cassava)
Cellulosic material (wood, agricultural wastes)
Pretreatment of raw material:
Depends on type of raw material.
Sugary materials : mild
Cellulosic: extensive acidic or enzyme hydrolysis to release monosaccharide units
PRE TREATMENT: Hydrolysis, clarification, filtration
Industrial production of alcohol and fructose from starch
pyruvate decarboxylase, TPP, Mg, - CO2
Alcohol dehydrogenase, NADH+H+
USED FOR FUEL,
FEED OR FERTILIZER, SCP, METHANOL
Anaerobic conditions after CO2 produced
Ethanol at high conc inhibits its own synthesis
Eg. Yeasts at 5% alcohol, growth ceases
1g glu to 0.511g ethanol (theory)
Pure substrates (glu, lac, suc): 95% conversion rate
Corn starch (industrial grade): 90%
100g pure glucose: 48.5g of ethanol produced, 46.5g CO2, 3.3g glycerol and 1.3g biomass
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
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 beetprimarily in Europe;
sugar cane in Brazil;
palm oil and miscanthusin 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.
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
Plant with sugar
Plant with starch
(maize, potato, cassava)
Plant with ligno-cellulose
ACETONE AND BUTANOL
Acetone used in manufacture of nitrocellulose for explosives
wood hydrolysates, molasses, starch, sucrose
Nowadays acetone and butanol are by products of petroleum industry
Fermentation is discontinued
Raw material: molasses, ammonium sulphate, Ca CO3, corn steep liquor, gassed with CO2, starting pH 5.8-6.0, 34oC, 36h
Phase I: rapid growth, acetic acid, butyric acid, titratable acidity, pH5.2
Phase II: incr in acetone, butanoldecr 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.
Sodium bisulfite blocks blocks alcohol production and large scale glycerol production
Fructose 1,6 bisPO4
Glyald 3 PO4
Glyald 3 PO4
ACETALD. SULFITE COMPLEX
Sodium bisulfite blocks
Sodium sulfite +CO2 ---> Sod bisulfite
Dunalieliasalinain 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 subtiliscapable of converting glucose to glycerol, ethanol,
Lactic acid, butanediol
Produces high yield at anaerobic conditions despite being an aerobic MO