Biodiesel Program in India – An Analysis

The Government of India approved the National Policy on Biofuels in December 2009. The biofuel policy encouraged the use of renewable energy resources as alternate fuels to supplement transport fuels (petrol and diesel for vehicles) and proposed a target of 20 percent biofuel blending (both biodiesel and bioethanol) by 2017. The government launched the National Biodiesel Mission (NBM) identifying Jatropha curcas as the most suitable tree-borne oilseed for biodiesel production.

The Planning Commission of India had set an ambitious target covering 11.2 to 13.4 million hectares of land under Jatropha cultivation by the end of the 11th Five-Year Plan. The central government and several state governments are providing fiscal incentives for supporting plantations of Jatropha and other non-edible oilseeds. Several public institutions, state biofuel boards, state agricultural universities and cooperative sectors are also supporting the biofuel mission in different capacities.

State of the Affairs

The biodiesel industry in India is still in infancy despite the fact that demand for diesel is five times higher than that for petrol. The government’s ambitious plan of producing sufficient biodiesel to meet its mandate of 20 percent diesel blending by 2012 was not realized due to a lack of sufficient Jatropha seeds to produce biodiesel.

Currently, Jatropha occupies only around 0.5 million hectares of low-quality wastelands across the country, of which 65-70 percent are new plantations of less than three years. Several corporations, petroleum companies and private companies have entered into a memorandum of understanding with state governments to establish and promote Jatropha plantations on government-owned wastelands or contract farming with small and medium farmers. However, only a few states have been able to actively promote Jatropha plantations despite government incentives.

Key Hurdles

The unavailability of sufficient feedstock and lack of R&D to evolve high-yielding drought tolerant Jatropha seeds have been major stumbling blocks. In addition, smaller land holdings, ownership issues with government or community-owned wastelands, lackluster progress by state governments and negligible commercial production of biodiesel have hampered the efforts and investments made by both private and public sector companies.

The non-availability of sufficient feedstock and lack of R&D to evolve high-yielding drought tolerant Jatropha seeds have been major stumbling blocks in biodiesel program in India. In addition, smaller land holdings, ownership issues with government or community-owned wastelands, lackluster progress by state governments and negligible commercial production of biodiesel have hampered the efforts and investments made by both private and public sector companies.

Another major obstacle in implementing the biodiesel programme has been the difficulty in initiating large-scale cultivation of Jatropha. The Jatropha production program was started without any planned varietal improvement program, and use of low-yielding cultivars made things difficult for smallholders. The higher gestation period of biodiesel crops (3–5 years for Jatropha and 6–8 years for Pongamia) results in a longer payback period and creates additional problems for farmers where state support is not readily available.

The Jatropha seed distribution channels are currently underdeveloped as sufficient numbers of processing industries are not operating. There are no specific markets for Jatropha seed supply and hence the middlemen play a major role in taking the seeds to the processing centres and this inflates the marketing margin.

Biodiesel distribution channels are virtually non-existent as most of the biofuel produced is used either by the producing companies for self-use or by certain transport companies on a trial basis. Further, the cost of biodiesel depends substantially on the cost of seeds and the economy of scale at which the processing plant is operating.

The lack of assured supplies of feedstock supply has hampered efforts by the private sector to set up biodiesel plants in India. In the absence of seed collection and oil extraction infrastructure, it becomes difficult to persuade entrepreneurs to install trans-esterification plants.

Energy Potential of Bagasse

Sugarcane is one of the most promising agricultural sources of biomass energy in the world. Sugarcane produces mainly two types of biomass, Cane Trash and Bagasse. Cane Trash is the field residue remaining after harvesting the Cane stalk while bagasse is the fibrous residue left over after milling of the Cane, with 45-50% moisture content and consisting of a mixture of hard fibre, with soft and smooth parenchymatous (pith) tissue with high hygroscopic property. Bagasse contains mainly cellulose, hemi cellulose, pentosans, lignin, Sugars, wax, and minerals. The quantity obtained varies from 22 to 36% on Cane and is mainly due to the fibre portion in Cane and the cleanliness of Cane supplied, which, in turn, depends on harvesting practices.

The composition of Bagasse depends on the variety and maturity of Sugarcane as well as harvesting methods applied and efficiency of the Sugar processing. Bagasse is usually combusted in furnaces to produce steam for power generation. Bagasse is also emerging as an attractive feedstock for bioethanol production. It is also utilized as the raw material for production of paper and as feedstock for cattle. The value of Bagasse as a fuel depends largely on its calorific value, which in turn is affected by its composition, especially with respect to its water content and to the calorific value of the Sugarcane crop, which depends mainly on its sucrose content.

Moisture contents is the main determinant of calorific value i.e. the lower the moisture content, the higher the calorific value. A good milling process will result in low moisture of 45% whereas 52% moisture would indicate poor milling efficiency. Most mills produce Bagasse of 48% moisture content, and most boilers are designed to burn Bagasse at around 50% moisture. Bagasse also contains approximately equal proportion of fibre (cellulose), the components of which are carbon, hydrogen and oxygen, some sucrose (1-2 %), and ash originating from extraneous matter. Extraneous matter content is higher with mechanical harvesting and subsequently results in lower calorific value.

For every 100 tons of Sugarcane crushed, a Sugar factory produces nearly 30 tons of wet Bagasse. Bagasse is often used as a primary fuel source for Sugar mills; when burned in quantity, it produces sufficient heat and electrical energy to supply all the needs of a typical Sugar mill, with energy to spare. The resulting CO2 emissions are equal to the amount of CO2 that the Sugarcane plant absorbed from the atmosphere during its growing phase, which makes the process of cogeneration greenhouse gas-neutral.

35MW Bagasse and Coal CHP Plant in Mauritius

Cogeneration of Bagasse is one of the most attractive and successful energy projects that have already been demonstrated in many Sugarcane producing countries such as Mauritius, Reunion Island, India and Brazil. Combined heat and power from Sugarcane in the form of power generation offers renewable energy options that promote sustainable development, take advantage of domestic resources, increase profitability and competitiveness in the industry, and cost-effectively address climate mitigation and other environmental goals.

Biochemical Conversion of Biomass

Biochemical conversion of biomass involves use of bacteria, microorganisms and enzymes to breakdown biomass into gaseous or liquid fuels, such as biogas or bioethanol. The most popular biochemical technologies are anaerobic digestion (or biomethanation) and fermentation. Anaerobic digestion is a series of chemical reactions during which organic material is decomposed through the metabolic pathways of naturally occurring microorganisms in an oxygen depleted environment. Biomass wastes can also yield liquid fuels, such as cellulosic ethanol, which can be used to replace petroleum-based fuels.

Anaerobic Digestion

Anaerobic digestion is the natural biological process which stabilizes organic waste in the absence of air and transforms it into biofertilizer and biogas. Anaerobic digestion is a reliable technology for the treatment of wet, organic waste.  Organic waste from various sources is biochemically degraded in highly controlled, oxygen-free conditions circumstances resulting in the production of biogas which can be used to produce both electricity and heat. Almost any organic material can be processed with anaerobic digestion. This includes biodegradable waste materials such as municipal solid waste, animal manure, poultry litter, food wastes, sewage and industrial wastes.

An anaerobic digestion plant produces two outputs, biogas and digestate, both can be further processed or utilized to produce secondary outputs. Biogas can be used for producing electricity and heat, as a natural gas substitute and also a transportation fuel. A combined heat and power plant system (CHP) not only generates power but also produces heat for in-house requirements to maintain desired temperature level in the digester during cold season. In Sweden, the compressed biogas is used as a transportation fuel for cars and buses. Biogas can also be upgraded and used in gas supply networks.

Working of Anaerobic Digestion Process

Digestate can be further processed to produce liquor and a fibrous material. The fiber, which can be processed into compost, is a bulky material with low levels of nutrients and can be used as a soil conditioner or a low level fertilizer. A high proportion of the nutrients remain in the liquor, which can be used as a liquid fertilizer.

Biofuel Production

A variety of fuels can be produced from waste resources including liquid fuels, such as ethanol, methanol, biodiesel, Fischer-Tropsch diesel, and gaseous fuels, such as hydrogen and methane. The resource base for biofuel production is composed of a wide variety of forestry and agricultural resources, industrial processing residues, and municipal solid and urban wood residues. Globally, biofuels are most commonly used to power vehicles, heat homes, and for cooking.

The largest potential feedstock for ethanol is lignocellulosic biomass wastes, which includes materials such as agricultural residues (corn stover, crop straws and bagasse), herbaceous crops (alfalfa, switchgrass), short rotation woody crops, forestry residues, waste paper and other wastes (municipal and industrial). Bioethanol production from these feedstocks could be an attractive alternative for disposal of these residues. Importantly, lignocellulosic feedstocks do not interfere with food security.

Ethanol from lignocellulosic biomass is produced mainly via biochemical routes. The three major steps involved are pretreatment, enzymatic hydrolysis, and fermentation. Biomass is pretreated to improve the accessibility of enzymes. After pretreatment, biomass undergoes enzymatic hydrolysis for conversion of polysaccharides into monomer sugars, such as glucose and xylose. Subsequently, sugars are fermented to ethanol by the use of different microorganisms.