In the context of energy security, rural development and climate change, India actively promotes the cultivation of
India relies heavily on crude oil imports, and this trend will continue due to the rapid growth of its economy and population. In order to foster energy security, India’s strategy is to focus efforts toward energy self-reliance and developing renewable energy options. In this context, India proposed an indicative biofuel blending target of 20 percent for both bioethanol and biodiesel by 2017 (B20 target) [
Besides fostering India’s energy security and combating climate change, another main driver was to increase the productivity of the estimated 55 million hectares of marginal land in India [
However, even if
Several studies have underlined that using
Further, Reinhard and Achten concluded that
Although
The huge variation of the LCA results indicates that there is no general answer whether
The main objective of the study is to assess the range of environmental impacts of different
The agricultural trials were established in 2008 at TERI’s experimental station at West Godavari, Andhra Pradesh, India. The area is situated at 17°00′N lat 81°10′E lon with an average daily temperature range of 22°C to 45°C. The annual precipitation is 1098 mm and the plantations are all established on red soil with sandy loam texture. Randomized block design was used for the experimental setup. The test plots are 81 m2 in size and contain 9 plants. Figure
Overview showing the nine different agricultural trials (S0–S8) using different inputs.
The environmental impacts over the whole value chain were estimated using the life cycle assessment (LCA) approach. The study was designed according to the ISO standards 14040/44 [
The performance of the different
The assessment comprises all the relevant process stages, from cultivation, processing, transport of the fuel to the filling station, and the use of the fuel in the vehicle, including also the infrastructure. Further, the
A system expansion approach according to the ISO standard is used to account for the substitution benefits of the byproducts in biodiesel production.
Flow diagram of the compared systems. All values refer to the functional unit of driving a default EURO 3 passenger car [
Specific data for the cultivation of
The energy balance of the compared systems was measured according to the cumulated energy demand (CED) methodology [
The global warming potential (GWP) was assessed with a 100-year time horizon and is based on the characterization factors provided by IPCC [
Since currently no specific impact assessment method for Indian environmental conditions was available, the midpoint impact categories of the Recipe methodology were used [
Impact categories used in this study.
Impact category | Unit | Source | Remarks |
---|---|---|---|
Cumulated energy demand | MJ non-renewable energy input | [ |
Only the non-renewable energy sources were considered (fossil and nuclear) |
Global warming potential | Kg CO2 eq. | [ |
Factors for GWP 100 years |
Ecotoxicity | CTUe | [ |
Recommended factors for aquatic ecotoxicity |
Terrestrial acidification | Kg SO2 eq. | [ |
World average factors |
Freshwater eutrophication | Kg P eq. | [ |
Generic factor |
Water consumption | m3 water consumption | [ |
Only blue water consumption was considered |
Land occupation | m2 land occupied | [ |
India’s largest fossil oil field is the offshore Mumbai High field. However, about 75% of India’s crude oil is imported mainly from onshore oil wells from the Middle East and Africa [
The lower heating value of fossil diesel is 42.8 MJ/kg and the fuel consumption of the EURO3 standard ecoinvent passenger car is 2.37 MJ/km [
The seedlings were raised in nurseries for 3 months before they were planted with a spacing of 3 m
The N2O, and NOx emissions to the air caused by the fertilizer application were calculated according to IPCC [
The rain-fed trials were drip-irrigated only once during plantation of the saplings. Each plant of the irrigated trails (S1 to S4) was drip irrigated with 8 L water per week during 24 weeks.
Standard transportation distances according to ecoinvent v2.2 were assumed for all input materials from the regional storage to the site [
The agronomic trials were conducted on fertile land, where previously maize was cultivated. The land use shift from agricultural land to
The carbon emissions from direct land use change were calculated according to the Tier 1 approach proposed by IPPC [
According to IPCC, the AGB and BGB of annual agricultural crops, such as maize, is assumed to be zero, since it is harvested every year. The AGB of
The agronomic trials were established in 2008 and thus have not yet reached maturity. Since the yield increase in the upcoming years is unknown, low-, medium-, and high-yield scenarios were assessed. In the conservative low-yield scenario the yield is assumed to be equal to the yield of year three. For the medium yield, a yield increase of 15% in year four and 5% in year five is assumed. While the high-yield scenario assumes a yield increase of 30% in year four and 10% in year five.
After harvesting, the remaining seed husks are removed and brought back to the field. The
Per kg
For this study a base catalytic transesterification reaction [
JME is transported from the transesterification plant to the filling station by truck and train. The energy content of JME is 38.9 MJ per kg [
Figure
Medium yield of the different cultivation systems (S0 to S8) in kilogram per hectare. The annual productivity of the low- and high-yield scenarios is indicated by the triangle, and rhombus, respectively.
The agronomic trials of this study indicate that the main yield increase under the conditions of the study site can be achieved with irrigation, followed by application of AM. By applying AM, the yield could be increased by 14% for intensive cultivation systems and by 4% for low-input cultivation systems. The yield response of only applying mineral fertilizer on relatively fertile land is marginal. As a consequence of the results, the application of mineral fertilizer on the test plots was stopped in 2011.
Figure
Cumulated nonrenewable energy demand of the different cultivation systems expressed as MJ per vehicle·km and compared with fossil diesel (dotted line). The total nonrenewable energy demand of the low-, medium- and high-yield scenarios are indicated, by the triangle, line segment, and rhombus, respectively.
Besides the cultivation practice, the substitution benefits of the press cake (1 MJ/km) and the glycerine (0.5 MJ/km) also influence the overall fossil energy demand of JME. Achten et al. showed that by using the press cake for biogas production, the nonrenewable energy demand of the JME value chain can be further reduced [
Figure
Global warming potential (GWP) of the different cultivation systems compared with fossil diesel (dotted line) expressed as kg CO2 equivalent per vehicle·km, without (a) and with (b) direct emissions from land use change. The total impact of the low-, medium- and high-yield scenarios are indicated by the triangle, line segment, and rhombus, respectively.
In general, the application of AM reduces the GWP, since the effect of the yield increase due to AM dominates over the GHG emissions caused during the AM production. The production, transport, and use of JME only show minor contributions to the overall impact, while the GHG emissions related to the processing are compensated for by the substitution effects of the byproducts.
In general, the GHG balance is sensitive to direct and indirect emissions of land transformation and occupation [
However, besides the direct land use change, the former activity (maize cultivation) might be shifted to other areas, leading to a sequence of displacement. The indirect displacement can take place very locally, when neighbouring farmers start cultivating the displaced product in order to satisfy the demand of the local market. Displacement can also take place on a large-scale, if the displaced product is demanded additionally on a global market. Finally, the additional demand for agricultural area could either be satisfied by intensification of the production or it finally leads to an expansion into natural areas. Bailis and McCarthy judged that the carbon stock of
In Figure
Mid-point indicators of different
Conventional diesel causes generally higher GHG emissions and depletes more fossil fuels as compared to JME (see Sections
The
The
For irrigated cultivation systems, driving one kilometre is linked to a blue
The
In addition, low-input cultivation systems also provide low-yields, and thus more
If the above presented results are compared with estimates about the current
In addition to the land use perspective, also socio-economic aspects further limit the expansion of
This study shows that the use of JME generally reduces the global warming potential and the nonrenewable energy demand as compared to fossil fuels. On the other hand, the environmental impacts on acidification, ecotoxicity, eutrophication, and water depletion showed increases. Nevertheless, the environmental impacts of the assessed
Therefore, one key aspect for achieving environmental sustainability is to increase the resource efficiency of
In addition, significant environmental benefits can only be achieved if
Besides optimizing the cultivation system, the efficient fuel production and the optimal use of the byproducts also influence the environmental performance of
Overall, the choice of the vehicle used on Indian roads directly affects fuel consumption and thus the environmental impact caused during the fuel production. Political instruments targeting the promotion of efficient cars and providing transport alternatives (i.e, using public transport) should go hand in hand with sustainable fuel production.
The financial support provided by the Swiss Agency for Development and Cooperation (SDC) is gratefully acknowledged.