Tuesday 24 September 2013

ENVIRONMENT

Impact of Ethanol blending with petrol
Oil import is the heaviest burden on India’s foreign exchange. In  the current scenario ,oil import contributes significantly for  the burgeoning Current account deficit, which is worrisome. One way to reduce petrol consumption is to use ethanol as a fuel. India being the second largest producer of sugar cane in the world , the risk and investment involved in ethanol production is far lower than in oil exploration and production. Blending of ethanol with petrol becomes a necessity.  In 2006, the government of India launched a programme of five per cent mandatory ethanol blending, but it is yet to materialise.
            Ethanol will help farmers sustain their income during the cyclical bumper harvests and their lower sugar prices, as is the prevailing situation this year. India will reduce its trade deficit and foreign exchange outflow. Moreover the reduction in green house gas (GHG) emissions from ethanol compared with fossil fuels is drastic.
            Brazil has already tasted it’s success in blending ethanol with petrol. Now  Brazilians have gone a step further into cellulosic ethanol technology( Using waste materials and bagasse from sugar mills). Brazil have flexi-fuel engines which run on 100 per cent ethanol or 100 per cent petrol or any combination of the two.
            Thus India has to replicate  the success of Brazil in cellulosic ethanol technology.
What is Cellulosic ethanol?
Ø  Cellulosic ethanol is a biofuel produced from wood, grasses, or the inedible parts of plants.
Ø  It is a type of biofuel produced from lignocellulose, a structural material that comprises much of the mass of plants.
Ø   Lignocellulose is composed mainly of cellulose, hemicellulose and lignin.


 Cellulosic ethanol production chart
1.      Biomass is harvested and delivered to the biorefinery.
2.      Biomass is cut into shreds and pretreated with heat and chemicals to make cellulose accessible to enzymes.
3.      Enzymes break down cellulose chains into sugars.
4.      Microbes ferment sugars into ethanol.
5.       Ethanol is purified through distillation and prepared for distribution.
There are  two ways of producing ethanol from cellulose :
Ø  Cellulolysis processes which consist of hydrolysis on pretreated lignocellulosic materials, using enzymes to break complex cellulose into simple sugars such as glucose, followed by fermentation and distillation.
Ø  Gasification that transforms the lignocellulosic raw material into gaseous carbon monoxide and hydrogen. These gases can be converted to ethanol by fermentation or chemical catalysis.
Advantages of Cellulosic ethanol


Ø  cellulosic material is widely available and is derived from a large resource of things. 
Ø  These crops are fast-growing and can be grown on many types of land which makes them more versatile.

Ø  Cellulosic ethanol can also be made from wood residues (chips and sawdust), municipal solid waste such as trash or garbage, paper and sewage sludge, cereal straws and grasses.











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