(644e) Life Cycle System Analysis of Bio Ethanol From Agro-Industrial Lignocellulosic Biomass in India

With recent volatility in oil prices and the mounting evidence of upcoming peaks in global oil and gas production, much attention has been given to the search for alternative energy sources and technologies. Increasing demand for energy and the depleting petroleum resources stimulates interest in alternative fuels, especially liquid transportation fuels. Due to increasing importance to reduce greenhouse gas emission to mitigate the climate change and energy security interest in Bioenergy sector growing worldwide [1] [2]. Though fossil fuel will continue to play dominant role in energy scenario for next few decades, due to its limited resource availability, non renewability and polluting nature is encorouraging renewable energy resources. [3]

As India is one of the fastest growing economies in the world and Energy plays critical role in socio-economic development. The energy policy of a country aims at efficiency and security and to provide access which being environment friendly and achievement of an optimum mix of primary resources for energy generation. Petro-based oil meets about 95% of the requirement for transportation fuels, and the demand has been rising steadily. Due to that India has been promoting the renewable transportation fuels and bio-ethanol is considered as one of the most important options. Currently the country mandates use of 5% ethanol blending in motor gasoline in several states; the current source is sugarcane molasses which is not sufficient to meet the current demand. An efficient and sustainable bioenergy production system is essential for meeting current ethanol demand for Transportation [1]. Lignocellulosic biomass is considered as the only foreseeable feasible and sustainable resource for renewable fuel but it needs to assess the resource potential to produce bio ethanol from agro-industrial lignocellulosic feedstock. Conversion of active agricultural lands to biofuel production is likely to adversely affect food security [4]. Sustainability has apparently become a vital issue for long-term industrial development and effective environmental protection, because of wider awareness of the limited availability of non-renewable resources.

While promoting the biofuel policy it becomes essential to assess the ripple effect of biofuel on ecosystem services such as land and water [5]. Such kind of system analysis has not been done for lignocellulosic biofuel and hence it has been important to analyse its impact widely and which will help to design policies specific to Indian context. Very few life cycle studies are available on biofuels in Indian context. The Availability of lignocellulosic feedstock for biofuel production will be the option to fill the gap between demand and supply of ethanol requirement for blending of gasoline. But it needs to analyze thoroughly because it may happen that impact may shift outside the analysis boundary. Some researchers assumed that this agro-industrial waste is freely available ignoring upstream energy and resource inputs and their impact. Due to Increased interest in biofuel it needs to assess thoroughly considering various allocation methods. This research aims to compute the sustainability of lignocellulosic biofuels, and its impact on ecosystem services. People often ignore farming inputs for lignocellulosic biofuels considering as it freely available. Such assumption transfers impacts outside analysis boundary.  Such analysis can be misleading for policy analysis and may result in shifting of the problem.

In this work, Life cycle assessments of lignocellulosic agricultural residues are compared among various feedstocks which are available abundantly in Indian context. Lignocellulosic feedstocks considered in this analysis are cotton stalk, Rice husk, Wheat stalk, sorghum stalk, Sugarcane bagasse. Boundary of analysis for this study consists of farming, transportation of residue from agricultural field to industrial site, Industrial process inputs for conversion of feedstock’s to ethanol. Data has been collected from various journal articles, Personnel communication, reports of Ministry of agriculture, Ministry of Statistics. Mass, Energy and Economic value allocation are compared for lignocellulosic feedstocks are considered in this study.Metrics computed for different feedstocks  are such as Life cycle energy return on investment, Life cycle Greenhouse gas emission per lit of ethanol produced, Land use per lit of ethanol produced, Water use per lit of ethanol produced.  These Metrics are also compared with other studies.

Results of this work can play an important role in devising the energy policy for any developing nation. This work provides systems view for biofuel policy development. Current work gives systematic analysis of lignocellulosic Bioenergy sector considering its impact and Potential to meet the requirement of bio ethanol from agro industrial residues. Current work provides support for decision making as it considers ecosystem services such as Land and Water. Metrics like Life cycle energy return on investment, Life cycle Greenhouse gas emission per lit of ethanol produced, Land use per lit of ethanol produced, Water use per lit of ethanol produced gives us broader picture from sustainability of energy feedstocks and which will help to avoid shifting of problem from outside boundary of analysis.

 References

[1] Sukumaran, R. K., V. J. Surender, R. Sindhu,  P. Binod, K. U. Janu, K.V.Sajna, K. P. Rajasree and A. Pandey, “ Lignocellulosic ethanol in India: Prospects, challenges and feedstock availability,” Bioresource Technology, 101,  4826 (2010).

[2] Hammerschlag, R., “Ethanol’s Energy Return on Investment: A Survey of the Literature 1990-Present,” Environ. Sci. Technol., 40, 1744 (2006).

[3] Hoefnagels, R.,   E. Smeets, A. Faaij ,”Greenhouse gas footprints of different biofuel production systems,” Renewable and Sustainable Energy Reviews, 14 , 1661 (2010).

 [4] Kumar , B.,  R. B. Hiremath , P. Balachandra, and  N.H. Ravindranath, “Bioenergy and food security: Indian context,” Energy for Sustainable Development, 13, 265 (2009).

[5] Gopalkrishnan, G., M. C. Negri, M. Wang, M. Wu, S.W. Snyder , and L. Lafreniere,” Biofuels, Land, and Water: A Systems Approach to Sustainability,”  Environ. Sci. Technol., 43, 6094 (2009).