Farming for Energy

by Dr. Anil K. Rajvanshi

A farmer is a multi purpose entrepreneur. His farm (factory) produces multiple crops (products) which he sells in the market. Yet only 25-40% of his crop (grain, fruits etc.) fetches him any money, whereas the rest of his produce (agricultural residues) which constitutes 60-75% of the product is totally wasted and most of the times he has to burn it in the fields.
I know no other industry in the world where 60-75% of the product is not sold or simply junked. No industry can survive on such low productivity. Yet for agriculture we do not think at all about this wastage. This besides the low support price by Government of India has made the farming non-remunerative.

Thus no amount of subsidies or government support price can help the farmers. The only way the farmers can be helped is when they get money for the agricultural residues. This can only happen when these residues can be used to produce energy for powering India. Any marginal farm can produce agricultural residues even if the main food crop fails. On an average a farmer can get an extra income of Rs. 2000-4000/acre from the residues alone if they are used for producing energy. This income can give him benefits even in case of a distress sale of his crop.

India produces ~ 600 million tons of agriculture residues every year. Majority of these are burnt in the fields as a solution to the waste disposal problem since the farmer wants his fields ready for next crop. A small part of the residues may be used for mulching, for fuel (for cooking) or as fodder.

Three types of energy can be produced from these residues. Liquid fuels such as ethanol or pyrolysis oil; gaseous fuels like biogas (methane) and electricity.

Ethanol fuel which can be used as transport fuel can be produced by lignocellulosic conversion of residues into ethanol. Extensive R&D is being done world over to optimize this technology. Few large scale plants in Canada, Japan and U.S. have already been set up on this technology. Nevertheless quite a lot of research still needs to be done to make ethanol production from residues economically viable and environmentally sound. Theoretically the residues in India can produce 156 billion liters of ethanol, which can take care of 42% of India’s oil demand for the year 2012.

Pyrolysis oil on the other hand is produced by rapid combustion of biomass and then condensing rapidly the ensuing vapors or smoke to yield oil which is nearly equivalent to diesel. Around 20% of charcoal is also produced as a by-product in the process. The charcoal can be used as cooking fuel for rural households. The pyrolysis oil technology was developed in early 1990s in Europe and North America and is now maturing. Consequently a few plants in Canada, U.S.A. and China have been set up and are producing oil from various agriculture residues. Nevertheless R&D is still needed in producing it economically, improving its keeping quality and making it suitable for use in existing internal combustion engines. Recent experiments in Sweden on running a 5 MW diesel power plant on pyrolysis oil have been successful. India can produce about 400 billion kg of pyrolysis oil from its agricultural residues which is equivalent to 80% of India’s total oil demand for 2012.

Similarly these residues can theoretically produce 80,000 MW of electric power year round through biomass-based power plants. This power is nearly 60% of the present installed capacity of India. The power plants could either be small scale (500 kW) running on producer gas from agricultural residues or medium scale (10-20 MW) running on direct combustion of these residues. The technology for this is very mature and there are thousands of such plants running all over the world.

A part of these agricultural residues can also be used via the bio-digester route to produce fertilizer for the crops and methane gas to either run rural transport, irrigation pump sets or for cooking purposes. Yet another stream can also be used for producing fodder for animals. Thus the residues if properly utilized can produce fuel, fodder and fertilizer besides taking care of a huge chunk of India’s energy needs. Which stream of residue conversion technology is eventually followed will depend upon the existing market forces.

Energy from agricultural residues in India could be of the order of thirty to fifty thousands crore per year industry. Besides it has the potential of producing 30 million jobs in rural areas.

As the demand for energy increases we may see huge tracts of land coming under energy crops like sugarcane for ethanol production or Jatropha for producing biodiesel etc. This can adversely effect the food production. Already these effects are felt in U.S. where huge acreage has been planted under corn for ethanol production. Similarly very large tracts of land in Brazil are being directed from food production to growing sugarcane for ethanol production. Use of agricultural residues for energy production is therefore the best bet to take care of food vs. fuel debate.

I strongly feel that when the farmers are forgotten, the long term sustainability of the country is threatened. When farms produce both food and fuel then their utility becomes manifold. In India 65% of its population depends on farming for their livelihood and with energy from agriculture as the major focus, India has the potential of becoming a high tech farming community.

Presently the growth of traditional agricultural sector is pegged at 2-3% per year. This low growth is mainly because the agriculture is non-remunerative. If both food and energy is produced from the same piece of land then India’s agricultural growth will be rapid and will bring in great wealth to rural areas.