This is a study by Dr. Balbir C Saini & Ar. Saubhagya
Ethanol as biofuel
Ethanol also known as ethyl alcohol, has been a part of human civilization from ancient times, though not as a transportation fuel. Mankind used it traditionally in the form of drinks and beverages, wines and hard liquor. More recently, with oil reserves running out and oil prices skyrocketing, it has become a substitute of petrol. The world’s need for energy is greater than ever before, and it is continuously increasing. Many countries now mandate mixing of 5 to 20 % ethanol with petrol sold as transport fuel. The use of biofuels for transport is becoming of increasing importance for a number of reasons, such as environmental concerns relating to climate change, depleting fossil fuel reserves, and reducing reliance on imports. According to the Federation of Indian Chambers of Commerce and Industry, India can save nearly 80 million liters of petrol annually if it is blended by 10%.
Biofuels have four main features:
- They are renewable fuels as are produced from a renewable energy source ; biomass. . Therefore, energy derived from biofuels can be replenished at a faster rate than the energy is consumed.
- Use of biofuels can contribute to energy security. It can reduce oil dependence on foreign energy sources and can also shift spending from foreign energy imports to domestically produced energy.
- Biofuels are expected to generate fewer greenhouse gas (GHG) emissions than are currently being produced by fossil fuels. Using bioethanol in place of petrol helps to reduce carbon dioxide (CO2) emissions by up 30-60% given today’s technology.
- Biofuels can contribute to boosting agricultural and rural development; creating new job opportunities and new income sources for farmers and rural areas.
These features are the main incentives for promoting biofuel policies in many countries and regions.
Major uses of ethanol :
Beverage alcohol, Fuel Alcohol, Industrial Alcohol, Rocket Fuel, Anticeptic and Chemical Industry. However, ethanol has three major uses: renewable fuel, as a beverage, and for Chemical industrial purposes. Of the three grades of ethanol, fuel-grade ethanol is driving record ethanol production in many countries
In 2008, the Ministry of New & Renewable Energy established a National Policy on Biofuels to limit the country’s future carbon footprint and dependence on foreign crude. The government said ethanol blended fuel would reduce India’s dependence on imported oil and enhance its energy security. It would also, we were told, cut India’s fuel bill substantially and boost the ailing sugar industry. The cues for those promises came from Brazil’s bio-fuel program which began in 1976 and transformed the South American nation into the world’s first sustainable bio-fuel economy. Close to 94 per cent of cars sold in Brazil are flexible fuel cars that can handle ethanol blends from 18 per cent upward. It even has 100 per cent ethanol vehicles. In Brazil ˃ 20% of cars (and some light aircraft) are able to use E100 % ethanol as fuel which includes ethanol- only engines and flex-fuel vehicles which are able to run with either neat ethanol, neat petrol, or any mixture of both. In Brazil, bioethanol now accounts for nearly 50% of the Brazilian transport fuel market, where petrol may now be regarded as the “ alternative” fuel.
In India under the Ethanol Blending Program (EPB), oil marketing companies (OMCs) were mandated to sell 5% ethanol–blended petrol from January 2003 and also, the Indian Government had proposed an ambitious target of 20% ethanol blending by 2017 and laid down a roadmap for the phased implementation of a program. However, today we are doing less than 2% of ethanol blending with petrol. The Indian government was hopeful of emulating Brazil’s success. It has the raw material – India is the second largest producer of sugar in the world (after Brazil), and ethanol is produced from molasses, a sugar byproduct
Table1. Present, production and consumption of bioethanol from molasses (crore litre) in India
|Sugar Industry||Per cent
|Transport Sector (Blending with petrol)||Chemical industry||Potable alcohol industry||Total|
The Indian Sugar Industry has the capacity to produce 250 crore litre of ethanol annually. From Table 1 it can be concluded that the ethanol produced from molasses is not sufficient even to meet the 5 % blending target of transport sector. Even if the current production of ethanol can satisfy the 5% blending mandate, however, as per Indian Government proposal of 20 % EBP by 2017, an additional 315 crore litre of ethanol will be required by 2017. If E85 buses are used in the cities in near future then 1955 crore litre is required and if ethanol engines are to be used then 100 % ethanol can be used and total about 2100 crore litre will be required provided other two industries (chemical and potable alcohol) do not increase their ethanol demand . Variation in blending % in different states is primarily due to the availability of ethanol in that particular state. Thus future ethanol demand cannot be met from sugarcane molasses and other feedstocks like corn which are also used for food as well as feed. Hence, we must think ahead and look for other sources of ethanol which are being used in other countries on commercial basis. Therefore, second generation bioethanol sources like cellulosic ethanol production have to be adopted.
Table 2. The feedstock used in biofuel production under different geographical zones.
|USA, Canada, the EU and China||Corn, willow|
|Brazil, Paraguay, Colombia, Philippines, Thailand, India||Sugarcane molasses, coffee pulp|
The Future of Bioethanol Production In India
Amendments to the fuel policy restrict import of green fuel directly or indirectly, therefore, OMCs now have to procure ethanol from sugar mills which are not capable of meeting the ethanol demand in India (Table1). Hence, there is a necessity for adopting other technologies available for bioethanol production in India. Biomass is a potential renewable energy source that could replace fossil energy for transportation. The use of food crops e.g. corn, sorghum for biofuel production may cause inflation of the cost of these crops leading to food insecurity. Countries with less food grain surpluses like India should look out for other alternative and non-edible agricultural residues sources like coffee pulp.
In Europe, dedicated short rotation coppice (SRC) plantations e.g. willow (high- yield energy crops) to provide lignocellulosic biomass for energy use under temperate climate are considered to be one of the main strategies towards developing a more sustainable energy supply, since they demand low input consumption levels and reduced land use.
However, In India we have established Salix(Willow) under sub tropical climate of tarai region of Uttarakhand and Uttar Pradesh with 3-4 times higher productivity in comparison to temperate climate of Europe. Short rotation coppice (SRC) like Salix spp is planted in spring from cuttings. After one year’s growth it is cut back to ground level to encourage the growth of multiple stems. The crop re-grows rapidly, reaching up to 6-8 m in height. The first commercial harvest usually occurs in tarai region of Uttarakhand and U.P. within two years after cut back and subsequently each year whereas in temperate climate same growth takes place in four years. The harvested crop is usually chipped and dried then stored until needed. One established crop of Salix can remain viable for 25-30 years which no other short rotation coppice tree can survive for such a long time. It is also a very good alternative compared to cutting down more “mature” forests .
Technology for Salix (willow) based bioethanol and electricity production is available in European countries e.g. USA, Switzerland, New Zealand
Table 3. Various uses of dedicated crop of Salix
|Salix part||Product||Process||Remarks||Technology availability|
|Salix Wood Chips||Electricity||Gasification + pyrolysis||Production of willow chips on an oven dry basis is higher in our plantation than the 10 t ha-1 y-1 over the 25 year rotation cycle|
|Salix Wood Chips||Bioethanol||By biochemical conversion
(saccharification and fermentation)
|Same as above||PURE POWER TECHNOLOGY for ethanol from willow
Also coffee pulp and coffee husk represents the most abundant and non-edible agricultural waste obtained by wet process and dry process, respectively. The use of this coffee waste as an alternative can also reduce the environmental impacts arising from dumping of the waste.
Table 4. Different uses of coffee residues
|Waste coffee residues (WCR)||Biodiesel||During preparation of INSTANT COFFEE||On average, the Waste coffee residue comprise 15% oil, by weight, which can be converted to a similar amount of biodiesel|
|Husk||Electricity||During dry processing of coffee||1 Ton of dried coffee fruit produce 0.52 Tons of coffee bean and 0.48 ton of Coffee husk|
|Pulp||Bioethanol||During wet processing of coffee||For every 2.0 Tons coffee cherries processed, nearly 1 Ton of wet pulp is generated taking up the space of almost 1 m3|
Coffee pulp contains 14.5 % sugar , therefore, is a potential source of bioethanol. In southwest Columbia, technology has been developed. Currently, India grows about 3 lakh tonnes coffee beans annually. For every 2 tons coffee cherries processed , nearly 1 ton pulp is generated. Therefore, at present about 6 lakh tonnes of pulp is available from coffee plantations in India . Also, we have developed technology for growing coffee under shade in plains of north India and if Coffee Board include this area in North India under Non-Traditional Category then coffee can be planted in 2 lakh ha under orchards of Uttarakhand and U.P. which would produce about 4 lakh tons of pulp in near future. Thus, huge amount of coffee pulp which is considered as waste can be used for making ethanol which will also make the environment safer.
In future, Commercialized Cellulosic Ethanol Production, involving commercial production of ethanol from wood and crop residues known as second generation bioethanol holds immense promise but may take some time before it becomes a reality. The countries attempting to develop sustainable bio-fuel economies have a lot to learn from the experience of those who have already taken big strides in this direction. Therefore, now India should also look beyond sugar mills to meet their ethanol demand from various second generation ethanol sources.