Biofuels –
Promise / Prospects
Anil Kumar
Rajvanshi, Vrijendra Singh and
Nandini Nimbkar
Nimbkar Agricultural Research Institute
(NARI)
Phaltan-415523,
Phone : 02166-222396
Fax : 02166-220945
e-mail address :nariphaltan@gmail.com
The prospects of using
agricultural material for biofuel in
Thus the values of the product of bio-energy and net returns (BENR) were estimated for the different cropping systems evaluated. The highest values of BENR under rainfed conditions were obtained from a combination of sweet sorghum in monsoon and either groundnut, rapeseed, mustard, sunflower or safflower (in that order) in winter. Under irrigation highest BENR values were obtained for castor in monsoon and sweet sorghum in winter followed by sweet sorghum in monsoon with either mustard or groundnut in winter.
It is shown that with this strategy not only the country can become self-sufficient in edible oil but will also have the potential of taking care indigenously of a substantial proportion of its energy needs.
In order that this strategy is followed on a large scale certain policy initiatives are suggested.
1. Introduction
The ever
rising cost of fossil fuel internationally has forced major world economies,
which are also major importers of fossil fuel, to examine renewable and cheaper
alternatives to fossil fuel to meet their energy demands. Biodiesel and bioethanol have emerged as the
most suitable renewable alternatives to fossil fuel as their quality
constituents match diesel and petrol respectively. In addition
they are less polluting than their fossil fuel counterparts.
Environmental concerns and the desire to be less dependent on imported fossil
fuel, have intensified worldwide efforts for production of biodiesel from
vegetable oils and ethanol from starch and sugar producing crops.
The use of
vegetable oil for energy purposes is not new. It has been used world over as a
source of energy for lighting and heating since time immemorial. As early as in
1900, a diesel-cycle engine was demonstrated to run wholly on groundnut oil at the
2. World
Biofuel Scenario
2.1
Area, production and productivity of oilseeds in the world and in
Worldwide,
oilseed crops occupy an area of 166.36 million hectares with a production of
295.6 million tonnes and productivity of 1777 kg/ha (FAO, 2003). In
2.2 Global biodiesel production scenario
Biodiesel is a fast-developing
alternative fuel in the
2.3 World ethanol production
With the
provision of addition of 5-10% of ethanol in petrol and diesel in most of the
crude oil importing countries, there has been a substantial rise in ethanol
production in last few years. Among the
ethanol producing countries,
Biofuels in
general have often been categorized as first and second generation. The first
generation biofuels are the fuels which are produced from conventional
agricultural crops by well-established technologies such as biodiesel from oil
crops and ethanol from sugar and starch producing crops. The second-generation
biofuels on the other hand are produced from the agricultural waste - mainly
the lignocellulosic material. However they require advanced production
(conversion) technologies. Overall, high energy conversion efficiencies and
least cost of production are the key factors for selecting biofuels for the
future.
2.4 Ethanol
production from crop residues
Enough availability of crop
residues as a source of feedstock is obviously mandatory for the production of
second-generation biofuels. Annual crop residue availability in the world is
estimated to be about four billion
tonnes, of which the
The
potential of bioethanol production from waste crops and crop residues was
estimated by Kim and Dale (2004).
According to them there are 74 Tg (Tg = Teragram = 1012 g = 1
million metric tonnes) of dry waste crops in the world that have a potential to
produce 49 GL (gigaliter or 1 billion liters) of bioethanol/year. It was also
estimated that conversion of 1.5 Pg (Pg = Petagram = 1015 g = 1
billion metric tonnes) of dry lignocellulosic residues of seven crops viz.
corn, barley, oat, rice, wheat, sorghum and sugar cane, could produce an
additional quantity of 442 GL of bioethanol per year. This potential bioethanol
production of 491 GL could replace 353 GL of petrol or about one-third of the
global petrol consumption. The ethanol production potential of residues from
lignocellulosic crops ranges from 0.26 to 0.31 L Kg-1 (Table 3). The
net energy yield of perennial crops ranges from 220-550 GJ/ha/yr, that of
grasses 220-260 GJ/ha/yr and that of sugar cane 400-500 GJ/ha/yr (Hamelinck and
Faaij, 2006).
Use of lignocellulosic
agricultural residues for energy production is thus very favourable and offers
good economic prospects for the future of biofuels. EU has set a target of 1 billion liters of
second generation bioethanol production to be achieved by 2012 (de Miguel,
2006). The prominent high potential fuels are ethanol produced from
agricultural residues rich in lignocellulose, synthetic diesel via
Fischer-Tropsch, methanol and hydrogen (Arthur D. Little, 1999; Katofsky, 1993;
Turkenburg, 2000; Williams et al., 1995). These four fuels are in
attractive stages of development.
2.5 Comparison
of biodiesel and ethanol
Before
striving for commercial scale biofuel production from food crops, it would be
of paramount importance to determine whether biofuels provide any benefit over
the fossil fuels they replace. This needs a thorough analysis of the direct and
indirect inputs and outputs for their full production and use life-cycles. To become a successful substitute for a fossil
fuel, an alternative fuel in addition to having superior environmental benefits
over the fossil fuel should also be produced economically and in sufficient
quantities to meet the energy requirements. Hill et al. (2006) analyzed
the net societal benefits of corn grain (Zea
mays ssp. mays) for ethanol and soybean (Glycine
max) oil for biodiesel - the two
important alternative transportation fuels in
The study
showed that both corn grain ethanol and soybean biodiesel recorded positive Net
Energy Balances (NEB). The
As far as
the life-cycle environmental effects were concerned, the study showed that both
corn and soybean production have negative environmental impacts through
movement of agrochemicals especially nitrogen (N), phosphorus (P) and
pesticides from farms to other habitats and aquifers. Data on efficiencies of
net energy production from agrochemical inputs in corn and soybean reveal
(after partitioning these inputs between the energy product and co-products),
that biodiesel uses only 1.0% of the N, 8.3% of the P and 13% of the pesticides
on weight basis. Although blending
ethanol with petrol at low levels as an oxygenate was reported to result in
lower emissions of carbon monoxide (CO), total life-cycle emissions of five
major air pollutants [CO, VOC, PM10, oxides of sulphur (SOx) and
oxides of nitrogen (NOx)] are higher with the “E85” (85% corn grain
ethanol-petrol blend) than with petrol per unit of energy released upon
combustion (Hill et al., 2006). The study further revealed
that production and use of corn grain ethanol releases 88% of the net green
house gas (GHG) emissions of production and combustion of an energetically
equivalent amount of petrol. On the other hand life-cycle GHG emissions of
soybean biodiesel were recorded to be 59% of those for diesel fuel.
Because fossil fuel energy use imposes environmental costs not considered in market prices, benefits of biofuel to society not only depend on its cost competitiveness compared to fossil fuel but also on its environmental costs and benefits vis-à-vis its fossil fuel alternatives. Subsidies for otherwise economically uncompetitive biofuels are justified if their life-cycle environmental impacts are sufficiently less than for alternatives.
3.
Status of Biofuel Production in
3.1 Biodiesel