Government of India (GOI) is accelerating its program of blending ethanol with petrol. It has announced that by 2023 there will be blending of 20% ethanol with petrol. The rationale given is that we have to reduce the dependence on
imported oil and reduce the environmental pollution. But the real reason for this push is that we have mountains of sugar stored in godowns in India which has to be reduced. Since there is little demand for our sugar in the export
market because of its poor quality and high price, the best alternative politically is to produce ethanol!
Though ethanol has been blended with petrol for automobiles in various countries, the use of ethanol for running automobiles is a total waste of a high-quality fuel. Automobile is an extremely inefficient mobility device. Its efficiency is mere 1-2% i.e., the total amount of energy used in transporting a passenger certain distance at a certain speed divided by energy input of petrol is less than 2%. And yet we persist in using a high-quality chemical like ethanol and other biomass-based fuels like biodiesel etc. for this purpose.
World over, countries are turning away from biofuels since they compete with food production and are neither sustainable nor economical. I feel the arable land should be used either for producing food for humans or fodder for
animals. The residues and other farm waste should be added back to the soil, either with or without composting, to improve its quality. Good land and precious water should not be wasted for producing biofuel for running inefficient automobiles.
The new ethanol blending policy has also given permission to produce ethanol directly from sugarcane juice and other biomass food grains like corn, sorghum, bajra, etc. Till now all the ethanol in India is produced from molasses – a byproduct of sugar industry. This new policy is really unfortunate since poor quality land with water shortage, as is the case in Maharashtra, will be used to produce food grains and sugarcane for ethanol production. The same land could easily produce food to feed the country or even exported so as to benefit farmers increase their remuneration.
The only success story in the world of ethanol use for automobiles is that of Brazil which has been producing ethanol from sugarcane since 1970s. Just like India, Brazil also has a powerful sugar lobby. The ethanol produced in Brazil is used in flex-fuel cars which can run on any concentration of ethanol. The program is not without hiccups and recent information shows that it is faltering. As the international price of fossil fuels fluctuate, the Brazilian ethanol program also goes through cycles of ups and downs. This creates hardships to the farmers since they cannot plan the sugarcane crop based upon fluctuating oil prices.
Ethanol as a chemical feedstock
However, there is a way out. Oil is used as chemical feedstock for plastics and a whole range of chemicals. Ethanol could be a good substitute for it if properly priced. Presently ethanol is used extensively in pharmaceutical, perfume, and disinfectant industries. With its additional use as a chemical feedstock quite a number of chemical industries can be set up for it.
I feel in India the sugar industry can become the hub of chemical revolution. Though the consumption of sugar is reducing all over the world, both sugar and ethanol can be excellent feedstock for chemical industry. Besides the
bagasse can produce electricity. So taluka-based industrial plants for producing electricity and chemical feedstock from sugarcane can be a viable and sustainable industry in rural areas.
The push for increasing ethanol blends also requires modifications of engines.Ethanol is hygroscopic in nature so tends to absorb moisture from air. This results in accumulation of water in fuel storage tank and starts the process of
rust formation which can ruin the engine and other parts. Also ethanol calorific value is only 60% that of petrol so blends generally reduce the mileage of vehicle. Finally ethanol is a very corrosive chemical, so it messes up with the
materials of fuel line and its components and sometimes gums up the fuel inlet to engine. This problem is more prevalent in older cars. In U.S. therefore they have put the upper limit of 10% ethanol in fuel blends.
Though the data from world over shows that the use of ethanol reduces air pollution from vehicles, the chaotic traffic conditions of city roads in India which make the cars run constantly in start and stop mode with low gear driving, may increase the emissions from ethanol blends. This needs to be studied more thoroughly.
Ethanol as cooking and lighting fuel for rural households
Most of the work on ethanol as a fuel has focused on automotive use. However a better use of ethanol can be a cooking fuel for household purposes. Rural households suffer from air pollution produced from biomass chulhas. Though GOI has provided LPG to most of these households, the program has suffered because of the problems in distribution of LPG and its cost escalation. Homegrown renewable ethanol fuel can reduce the pollution and be cost effective.
Our Institute, Nimbkar Agricultural Research Institute (NARI), pioneered in early 1980s the development of ethanol from sweet sorghum and its use as a cooking and lighting fuel. This work at NARI was initiated to use ethanol to
replace kerosene as a cooking and lighting fuel in rural households. NARI thus developed lanterns and stoves running on low concentration ethanol. However in the 1980s and 1990s there were no takers for ethanol as an automobile fuel
and this also affected the spread of ethanol for cooking and lighting. Besides the stringent and archaic excise laws have also hampered the spread of this technology.
A much better alternative to using biofuels for automobiles is to develop electric mobility. On energy of fuel to wheel basis, electric vehicles are three times more efficient than internal combustion (IC) systems. This is because of high efficiencies of D.C. motors (80-90%) as compared to 25-30% efficiencies of IC engines.
Since biofuels are biomass and land-based it is instructive to compare their solar efficiency to electricity generation by photovoltaic (PV) systems. The electric vehicles running on PV electricity, in this comparison, are 100 times more efficient than biofuel-based IC engines. This is because the average overall solar efficiency of ethanol conversion from crops is about 0.1-0.2% as compared to 10% solar efficiency of PV modules. These efficiencies also consider the charging and discharging of batteries for electric vehicles. Presently around 35% of the energy is lost during charging/discharging cycle.However the cost of batteries and charging stations is a major stumbling block in large scale usage of electric vehicles in India.But all this advantage of electric vehicles vanishes if electricity is produced from coal and fossil fuel fired power plants.
Another attractive route for ethanol use for automobiles is in hybrid electric vehicles. A small internal combustion engine running at full load on ethanol will charge the batteries through a generator/motor so it can run the electric
vehicle. This will have the following advantage:
1. It will reduce the environment pollution. IC engines running at full load have clean combustion and high efficiency.
2. Will help in introducing electric mobility in India rapidly. Hybrid engine vehicles can also be charged by electric outlets and hence will help charging station proliferation. Thus the use of ethanol will not only extend the range of these vehicles, but they can be charged like a regular electric vehicle.