 |
| |
| Biodiesel in India has the potential to address five of its most important development challenges. |
|
 |
Biodiesel has the potential to contribute to India’s energy supply and to decrease its dependency on oil imports. Due to high economic growth, continuous population growth, and increasing urbanization, Indian energy and oil demand has risen significantly and will keep on rising in the near future. With a constant domestic oil production at only 33-34 mio t per year, India depends strongly on oil imports to satisfy the increasing energy demand, exposing the Indian economy to the oil price fluctuations of the world market. From 1990/91 to 2006/07, Indian oil imports increased dramatically from 21 to 111 mio t. As world market prices for crude oil tripled during the same period imports have a strong effect on India’s foreign exchange expenditure, its trade balance and economy as a whole. Biodiesel production has the potential to reduce pressure on oil imports. The draft National Biodiesel Mission of 2003 suggested to aim at substituting 20% of transport diesel by 2011-12, requiring 13,28 mio t of Biodiesel. Thereby India would save at least Rs. 1.17 billion of foreign exchange and improve the trade balance by at least 15%. |
| |
|
|
Second potential of Biodiesel is to reduce India’s carbon-dioxide emissions. To achieve its development targets, the Government of India aims to achieve 8% growth in GDP, requiring substantial additional energy inputs. Therefore, economic growth is directly linked to growing GHG emissions, which have increased by about 7 % annually during the 1990s. Despite relatively low levels of per capita emissions, estimations suggest that until 2020 they will increase by 400% compared to 1990. As the Government of India is committed to promote renewable energies and to shift to a low carbon growth trajectory, promotion of Biodiesel is one way of reaching this goal. Furthermore, Biodiesel activities can be an opportunity to receive additional funds through the Clean Development Mechanism established by the Kyoto Protocol. |
| |
|
|
The third potential of Biodiesel is to contribute to the rural economy and to create employment and income for the rural poor. While the Indian economy has grown rapidly in the last decade, little development has taken place in the rural areas, home to three quarters of the Indian poor. While India’s total economy and particularly the service sector is booming, the agricultural sector has almost stagnated. This adversely affects the rural poor who depend on agriculture for their livelihoods (World Bank, 2006b). The Indian agricultural sector is characterized by low productivity: The sector contributes only 18% to the GDP although it employs almost 60% of the Indian workforce. |
|
|
Rural energy security is a fourth concern to which Biodiesel might contribute. According to the 2001 Census of India, less than 50% of India’s rural population has access to electricity. Since electricity not only increases living standards but is also indispensable for many productive and economic activities, there is a close connection between access to electricity and poverty alleviation The Indian Ministry of Power has set the target to electrify about 80,000 villages by 2012. Out of these, 18,000 villages in remote and inaccessible locations need decentralized solutions for energy supply. Biodiesel – or its preliminary product, Straight Vegetable Oil (SVO) if produced in the respective villages, can be one option for decentralized reliable and affordable electricity supply and a renewable energy source. |
|
|
Fifth, cultivation of TBOs can be conducive to the protection of natural resources. In India, large amounts of land are not suitable for productive purposes due to harsh agro climatic conditions or unsustainable usage. The Wastelands Atlas of India, a satellite based land survey by the Indian Ministry of Rural Development, identifies 553,000 km˛ of the 3.3 Mio.km˛ total land area in India as wastelands. Particularly the 108,000 km˛ of degraded forests and 151,000 km˛ of land with only scrub vegetation – amounting to more than 8% of the total geographic area in India (ibid.) – need afforestation and soil improvement to prevent further degradation.20 Being more drought resistant than most other crops and trees, oil-bearing trees can be an option to contribute to the rehabilitation of degraded land through stabilizing soil, improving manure cover and bringing degraded land back to productive use. |
|
Emission Characteristics |
|
| Biodiesel is the only alternative fuel to have a complete evaluation of emission results and potential health effects submitted to the U.S.EPA under the Clean Air Act Section 211(b). These programs include the most stringent emissions testing protocols ever required by EPA for certification of fuels in the U.S. Emission results for pure Biodiesel (B100) and mixed Biodiesel (B20-20% Biodiesel and 80% petrodiesel) compared to conventional diesel are given below: |
| |
Biodiesel Emissions Compared to Conventional Diesel |
|
| Emissions |
B100 |
B20 |
|
| Regulated Emissions |
|
|
|
| Total Unburned Hydrocarbons |
-93% |
-30% |
| Carbon Monoxide |
-50% |
-20% |
| Particulate Matter |
-30% |
-22% |
| NOx |
+13% |
+2% |
|
| Non-Regulated Emissions |
|
|
|
| Sulphates |
-100% |
-20%* |
| Polyciclic Aromatic Hydrocarbons (PAH)** |
-80% |
-13% |
| NPAH (Nitrated PAHs)** |
-90% |
-50%*** |
| Ozone Potential of Speciated HC |
-50% |
-10% |
| |
| Life-Cycle Emissions |
| Carbon Dioxide (LCA) |
-80% |
| Sulphur Dioxide (LCA) |
-100% |
| |
|
|
*Estimated from B100 results. **Average reduction across all compounds measured. ***2-nitroflourine results were within test method variability. |
|
|
The use of Biodiesel in a conventional diesel engine results in substantial reduction of unburned hydrocarbons, carbon monoxide and particulate matter. Emissions of nitrogen dioxides are either slightly reduced or slightly increased depending on the duty cycle or testing methods. Biodiesel decreases the solid carbon fraction of particulate matter (since the oxygen in the fuel enables more complete combustion to CO2), eliminates the sulphur fraction (as there is no sulphur in the fuel), while the soluble or hydrogen fraction stays the same or is increased.
The life-cycle production and use of biodiesel produces approximately 80% less carbon dioxide and almost 100% less sulphur dioxide compared to conventional diesel. From the above table it is clear that biodiesel gives a distinct emission benefit almost for all regulated and non-regulated pollutants when compared to conventional diesel fuel but emissions of Nox appear to increase from biodiesel. Nox increases with the increase in concentration of biodiesel in the mixture of biodiesel and petrodiesel. This increase in Nox may be due to the high temperature generated in the fairly complete combustion process on account of adequate presence of oxygen in the fuel. This increase in Nox emissions may be neutralized by the efficient use of Nox control technologies, which fits better with almost nil sulphur biodiesel then conventional diesel containing sulphur. A comparative emission scenario with petrodiesel, biodiesel and biodiesel blends evolved from a real-life fleet study is presented in Figure below. |
| |
|
 |
|
CASE-I: Petrodiesel with 0.05% sulphur. CASE-II: 20% biodiesel with 3-degree injection timing adjustment. CASE-III: CASE-II + Catalytic Converter (Source: Twin Rivers Technologies, USA). |
|
Comparison of particulate composition: Diesel Vs. Biodiesel |
The below mentioned table gives a comparison of particulate emissions of all forms (insoluble, fuel soluble, lube soluble and inorganic soluble) from petrodiesel and RSME (biodiesel from rapeseed methyl ester).
|
Table:Particulate Composition-Diesel Vs. Biodiesel |
|
| Test |
Fuel |
Total PM
(g/mile) |
Insolubles
(g/mile) |
Fuel Solubles
(g/mile) |
Lube Solubles
(g/mile) |
Soluble Inorganic
(g/mile) |
Cold FTP
Difference % |
Diesel |
0.311 |
0.259 |
0.021 |
0.031 |
17 |
| RSME |
0.258
-17% |
0.118
-54% |
0.104
+49% |
0.036
+16% |
54
+318% |
Hot FTP
Difference % |
Diesel |
0.239 |
0.206 |
0.012 |
0.021 |
14 |
| RSME |
0.190
-21% |
0.101
-51% |
0.068
+567% |
0.021
0% |
47
+335 |
| |
|
|
|
|
|
|
(Source: Concawe Report No. 2/95). |
| |
|
The study on mechanism of soot formation from diesel as well as biodiesel (RSME) indicates reduction in total particulate matter. When the engine is operated on RSME, soot emissions (insolubles) are dramatically reduced, but the proportion of emissions composed of fuel derived hydrocarbons (fuel solubles), condensed on the soot, is much higher. This implies that the RSME may not burn to completion as readily as diesel fuel. It should, however, be noted that gaseous HC emissions were reduced with RSME in the above tests. Since concern over particulates arises partly from the potential harmful effects of the soluble fraction, it might be suspected that emissions from RSME would be more harmful however data shows no tendency for the mutagenicity of exhaust gas to increase for a vehicle running on 20% RSME and 80% diesel blends. |
|
Emissions of Greenhouse gas |
Comparative emissions of greenhouse gases for diesel and biodiesel in various stagers of life cycle is depicted in below mentioned Table Life cycle analysis for various fuels including biofuels is diagrammatically represented in Figure-3, which shows that biodiesel (RSME) has the lowest Greenhouse emissions followed by ethanol from wood. Emissions of greenhouse gases during the production of diesel are about 32 g/km. These are hardly a half of the emissions from producing biodiesel even when straw rather than electricity is used to fire the processing. However, this difference is far outweighed by the emissions of CO2 during the combustion of the diesel itself (245 g/km).
|
 |
|
Table: Emissions of Greenhouse Gases (g/km) |
|
| |
Diesel |
|
Biodiesel |
| |
|
|
|
| Extraction |
15.84 |
Fertiliser Production |
15 |
| Transport |
2.74 |
Fertiliser Application |
10 |
| Refining |
13.63 |
Agricultural Machinery* |
25 |
| Distribution |
0.95 |
Oil Production |
3 |
| Vehicle Operation |
245 |
Processing Straw** |
1 |
| |
|
Processing Gas |
17 |
| |
|
Transport |
5 |
| |
|
Vehicle Operation |
0 |
| Total |
278.16 |
Total (Straw Processing) |
59 |
| |
|
Total (Gas Processing) |
75 |
| |
*Assumed mineral diesel oil used.
**Emissions of straw include those from transporting straw. |
|
|
| |
|
| |
