The Government of India is accelerating its program of blending ethanol with petrol.  It has announced that by 2023 there will be blending of 20 percent ethanol with petrol. The rationale given is that we have to lessen the dependence on imported oil and cut down on 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, using it for for running automobiles is a total waste of high-quality fuel. An automobile is an extremely inefficient mobility device. it's efficiency is mere 1-2 percent, ie 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 percent.  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 permitted production of ethanol directly from sugarcane juice and other biomass food grains like corn, sorghum (Indian millet), bajra (pearl millet), etc. Till now ethanol in India is produced from molasses – a 

by-product of the sugar industry. The 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 export to help farmers increase their remuneration.

The only success story in the world of use of ethanol for automobiles is that of Brazil which has been producing ethanol from sugarcane since the 1970s. Just like India, Brazil also has a powerful sugar lobby. The ethanol produced in Brazil is used in flexi-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 fluctuates, the Brazilian ethanol program also goes through cycles of ups and downs. This creates hardships for the farmers since they cannot plan the sugarcane crop based upon fluctuating oil prices.

Ethanol as 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 few chemical industries can be set up for it.

I feel in India the sugar industry can become the hub of the 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, and so tends to absorb moisture from the air. This results in the accumulation of water in the fuel storage tank and starts the process of rust formation which can ruin the engine and other parts. 

Also, ethanol's calorific value is only 60 percent that of petrol, so blends generally reduce the mileage of vehicles. 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 the engine. This problem is more prevalent in older cars. In the US therefore they have put the upper limit of 10 percent ethanol in fuel blends.

Though the data from the 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 the 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 fuel  

Most of the work on ethanol as a fuel has focused on automotive use. However, better use of ethanol can be in the form of a cooking fuel for household purposes. Rural households suffer from air pollution produced from biomass chulhas (ovens). Though the Indian government has provided LPG to most of these households, the program has suffered because of the problems in distribution of LPG and its cost escalation. Home-grown renewable ethanol fuel can reduce pollution and be cost-effective.

Our Institute, Nimbkar Agricultural Research Institute (NARI), pioneered in the 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 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.  

Electric mobility

 
A much better alternative to using bio-fuels for automobiles is to develop electric mobility. On the energy of the fuel-to-wheel basis, electric vehicles are three times more efficient than internal combustion (IC) systems. This is because of the high efficiencies of D.C. motors (80-90 percent) as compared to 25-30 percent 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 percent as compared to the 10 percent solar efficiency of PV modules. These efficiencies also consider the charging and discharging of batteries for electric vehicles. Presently around 35 percent of the energy is lost during the charging/discharging cycle. However, the cost of batteries and charging stations is a major stumbling block in the large-scale usage of electric vehicles in India.

But all these advantages of electric vehicles vanish 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 advantages:

1. It will reduce environmental pollution.  IC engines running at full load have clean combustion and high efficiency.

2. it 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.

(Anil K. Rajvanshi is Director and Hon. Secretary, Nimbkar Agricultural Research Institute, Phaltan, Maharashtra. He can be contacted at anilrajvanshi50@gmail.com. Nandini Nimbkar is president, Nari. The views are those of the writers)