Bio-fuels and Climate Change Mitigation

Bio-fuels and Climate Change Mitigation

From Prof Emeritus.

Professor Emeritus ,Former Head of the Department of Botany, and Director Life Sciences, University of Rajasthan, Jaipur. 302004, India.

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Global climate change has stimulated efforts to reduce CO₂ emissions. Photosynthetic organisms use solar energy to generate reducing equivalents and incorporate atmospheric CO₂ into organic molecules. Cellular phenotype is a manifestation of gene expression levels, metabolic demand, resource availability, and cellular stresses. The variation in raw material for production of biofuels ranges from hydrocarbon yielding plants, non-edible and edible oil yielding plant, corn ,sugarcane to lingo-cellulosic waste to algal biofuels.  Currently, cellulosic biofuels and algal biodiesels   are prominent biological approaches to sequester rand convert CO₂. 

Today, ethanol and biodiesel are predominantly produced from corn kernels, sugar cane or soybean oil. However another biofuel feedstock, lignocelluloses—the most abundant biological material on earth is being explored. Lignocellulosesis everywhere—wheat straw, corn husks, prairie grass, discarded rice hulls or trees. The race is on to optimize the technology that can produce biofuels from lignocelluloses sources more efficiently—and biotech companies are in the running. There is  campaign, which advocates that 25% of US energy come from arable land by 2025. The EU had called for a threefold  increase in biofuel use by 2010, to 5.75% of transportation fuel.

 1. INTRODUCTION:

           Use of biomass for energy and industry allows a significant quantity of hydrocarbons to be consumed without increasing the CO₂ content of the atmosphere and thus makes a positive contribution to the Greehouse effect and to the problems of "global change" as occurs in both industrialized and developing countries (Kumar,2008, Kumar 2011)  Climate change is any long-term significant change  in  average temperature, precipitation and wind patterns. It takes place due to emissions of greenhouse gases. Carbon dioxide (CO₂)is the most important greenhouse gas and increasing the use of biomass for energy is an important option for reducing CO₂emissions. Carbon dioxide emission is projected to grow from 5.8 billion tonnes carbon equivalent in 1990 to 7.8 billion tonnes in 2010 and 9.8 billion tonnes by 2020 (Fig.1)  (Kumar, 2001) .

          The  Kyoto conference agreement indicates the role clean energy sources will play in future. Biomass is renewable, non pollutant and available worldwide as agricultural residues, short rotation forests and crops. Thermochemical conversion using low temperature processes are among the suitable technologies to promote a sustainable and environmentally friendly development. Biomass can play a dual role in greenhouse gas mitigation related to the objectives of the United Nations Framework Convention on Climate Change (UNFCC)   i.e. as an energy source to substitute for fossil fuels and as a carbon store. The fact that nearly 90 percent of the worlds population will reside in developing countries by 2050 probably implies that local solutions for energy needs will have to be found to cope up with the local energy needs on one hand and environment protection on the other hand (Table 2).Biomass should be used instead of fossil energy carriers in order to reduce  (i) CO2 emissions(ii) the anticipated resource scarcity of fossil fuels and  (iii) need to import fuels from abroad(Kumar, 2001).

1.1 Global land availability and biomass production: 

           Global land availability estimates for energy crop production vary widely between 350 and 950 million hectares (Alexandratos, 1995). Biomass resources are potentially the worlds largest and sustainable energy source a renewable resource comprising 220 billion oven dry tones (about 4500 EJ) of annual primary production. The annual bio-energy potential is about 2900 EJ though only270  EJ could be considered available  on a sustainable basis and at competitive prices. Current commercial and non-commercial biomass use for energy is estimated at between 20 and 60 EJ/are presenting about 6 to 17 % of the world primary energy.  Most of the biomass is used in developing countries where it is likely to account for roughly one third of primary energy. As a comparison, the share of primary energy provided by biomass in industrialized countries is small and is estimated at about 3 % or less (Fig 3).Agriculture and allied sectors contribute nearly 22 percent of Gross Domestic Product (GDP of India), while about 65-70 percent of the population is dependent on agriculture for their livelihood. The agricultural output,however, depends on monsoon as nearly 60 percent of area sown is dependent on rainfall. Most of the population dependent on agriculture in India uses  biomass for fuel in open chulhas ( firestoves) with poor  fuel efficiency and lot of smoke generation causing serious asthmatic problems in rural women and children. 

1.2 Advantages of using biofuels:

            There are several advantages of using biofuels: biodiesel burns up to 75% cleaner than petroleum diesel fuel. Biodiesel reduces unburned hydrocarbons (93% less), carbon monoxide (50% less) and particulate matter (30% less) in exhaust fumes, as well as cancer-causing PAH (80% less) and nitrited PAH compounds (90% less) (US Environmental Protection Agency), and Sulphurdioxide emissions are eliminated (biodiesel contains no sulphur).  Biodiesel is plant-based and using it adds no extra CO₂ greenhouse gas to the atmosphere. Nitrogen oxide (NOx) emissions may increase or decrease with biodiesel but can be reduced to well below petro-diesel fuel levels. Biodiesel exhaust is not offensive and doesn't cause eye irritation.

             Biodiesel can be used in any diesel engine withou tmodification. Biodiesel can be mixed with petro-diesel in any proportion, with no need for a mixing additive.  Biodiesel has a highercetane number than petroleum diesel because of its oxygen content. The higher the cetanenumber,the more efficient the fuel -- the engine starts more easily, runs better and burns cleaner.  With slight variations depending on the vehicle, performance and fuel economy with biodiesel is the same as with petro-diesel. Biodiesel is a much better lubricant than petro-dieseland extends engine life -- even a small amount of biodiesel means cleaner emissions and better engine lubrication: 1% biodiesel added to petro-diesel will increase lubricity by 65%. The ozone-forming (smog) potential of biodies elemissions is nearly 50% less than petro-diesel emissions.  

 1.3 EU mandate:

        Worldwide production of biodiesel increased by 60% in 2005, and ethanol by 19% over theprevious year’s production, as per World watch Institute, USA. The EU mandated that three times more than the current level of 2% of the total energy contentof petrol and diesel needs to come from renewable fuels. Countries like Thailand are aiming for a 10% renewable mix in the next five years; India 20%by 2020. Sweden has stated that it aims to become 100% energy independent by 2020; most of this independence will come through its own nuclear power, but renewable fuels will likely make up the balance..

1.4 Objectives  of Biofuel production: 

•     First generation biofuel: salt and drought resistance for growing in wastelands.

•   Second and third generation biofuels:altering host material and /or developing new enzyme systems.

•   Metabolic engineering for entire product

•   Industrial application of biofuel inclusive of related bio products of commercial value from fourth generation products. 

      Next generation bio-fuels shall involve technical components (1) Biological sciences: Plant biotechnology, Cellular andmolecular biology, microbial /industrial biotechnology. (2) Chemical technologysciences: catalysis, reaction engineering and separations

 Present status and future prospects: 

•       1. Wood, wood chips agriculture waste to Briquetting, Gasifier, Vacuumpyrolysis or Bio-gas, heat and electricity generation.

•       2. Oil to trans-esterification to obtain Fatty acid methyl ester (FAME)e.g. Rape seed methyl ester ( RME)

•       3. Liquid hydrocarbons to hydro-cracking – cracking  of tri-terpenoid chain and adding of hydrogenusing zeolite catalyst in bio-refinery.

 Biodiesel: 

•       Technically, Mono-alkyl esters of long chain fatty acids derivedfrom renewable lipid feedstock such as vegetable oils and animal fats for use in Compression Ignition engines”.

•       The definition eliminates pure vegetable oils

Dependingon the feed stock it may be referred as

–      Soybean methyl ester - SME or SOME

–      Rape methyl ester - RME

–      Fatty acid methyl ester - FAME (a collective term including both of theabove)

–      Vegetable oil methyl ester - VOME yielding plants provide bio-diesel. 

References: 

Alexandratos, N. Worldagriculture: towards 2010: an FAO study, Food&Agriculture Org.; 1995.

Atsumi, S., Hanai, T. and Liao,J. C. 'Non-fermentative pathways for synthesis of branched-chain higheralcohols as biofuels', Nature, 2008;  451: 86-89.

Bhatia, V. K., Srivastava, G.S., Garg, V. K., Gupta, Y. K., Rawat, S. S. and Singh, J. 'Study of laticiferous (latex-bearing) plants as potential petro-crops', Fuel, 1983; 62:  953-955.

Calvin, M. 'Petroleum Plantations for Fuel and Materials', Bioscience, 1979;  29:  533-38.

Garg, J. and Kumar, A. 'Studieson biomass production and improvement in biocrude content', inWorkshop on    Petrocrops, New Delhi, 1986; 69-81.

Garg, J. and Kumar, A. Effectof growth regulators on the growth, chlorophyll development and productivity ofEuphorbia lathyris L., a hydrocarbon yielding plant. In:Progress inPhotosynthesis Research. , The Netherlands + Martinus Nijhoff Publishers;1987a.

Garg, J. and Kumar, A. 'Effectof growth regulators on the growth, chlorophyll development and productivity ofEuphorbia lathyris L.A hydrocarbon yielding plant. Progress in PhotosynthesisResearch', J. Biggins, 1987b; 4:  403-406.

Garg, J. and Kumar, A.Improving growth and hydrocarbon yield of Euphorbia lathyris L. In: BioenergySociety Fourth convention and Symposium 87, R.N. Sharma, O.P. Vimal and A.N.Mathur, (eds.), New Delhi, ; 1987c.

Garg, J. and Kumar, A. 'Somestudies on charcoal rot of Euphorbia lathyris caused by Macrophominaphaseolina', Indian Phytopathology 1987c; 41: 257-260.

Garg, J. and Kumar, A.'Influence of salinity on growth and hydrocarbon yield of Euphorbia lathyris',J. Indian Bot. Soc., 1989a;  68:  201-204.

Garg, J. and Kumar, A. 'Potential petro crops for Rajasthan', J. Indian Bot. Soc., 1989b; 68:  199-200.

Garg, J. and Kumar, A.'Potential petro crops for Rajasthan', J. Indian Bot. Soc., 1989c; 68:  199-200.

Garg, J. and Kumar, A.'Improving the growth and hydrocarbon yield of Euphorbia lathyris L. insemi-arid regions of Rajasthan. In : Biomass for Energy and Industry (G.Grassi, G. Gosse&G. dos Santos. Eds.)', Elsevier Applied Science, London, 1990a; I:  1.527-1.531.

Garg, J. and Kumar, A. 'Improvingthe growth and hydrocarbon yield of Euphorbia lathyris L. in semi-arid regionsof Rajasthan. In: Biomass for Energy and Industry, Eds. Grassi, G., Gosse, G.and Santos, G. (London + Elsevier Applied Science)', 1990b:  1.527-1.531.

Johari, S. and Kumar, A.'Effect of N, P and K on growth and biocrude yield of Euphorbiaantisyphilitica', Ann. Arid Zone, 1992;31:  313-314.

Johari, S. and Kumar, A. 'Influence of growth regulators on biomas and hydrocarbon yield from Euphorbiaantisyphilitica (Zucc)', J. Phytol Res., 1994;7:  65-68.

Johari, S., Roy, S. and Kumar,A. 'Influence of edaphic and nutritional factors on growth and hydrocarbonyield of Euphorbia antisyphilitica Zucc. In: Biomass for Energy and Industry.Eds. Grassi, G., Gosse, G. and Santos, G. (London + Elsevier Applied Science)',1, 1990:  .522-1.526.

Johari, S., Roy, S. and Kumar,A. Influence of growth regulators on biomass and hydrocarbon yield fromEuphorbia antisyphilitica Zucc. In: Bioenergy for Humid and Semi-humid Regions(H.L. Sharma and R.N. Sharma, eds.) New Delhi; 1991.

Johri, S. and Kumar, A.'Charcoal rot of Candelilla(Euphorbia antisyphilitica Zucc.) caused byMacrophomina phaseolina(Tassi) Goid', Indian Journal of Mycology and PlantPathology, 1993;  23: 317.

Keasling, J. D. 'Syntheticbiology for synthetic chemistry', ACS Chemical Biology, 2008;  3:  64-76.

Keasling, J. D. and Chou, H.'Metabolic engineering delivers next-generation biofuels', Nature biotechnology, 2008; 26:  298-299.

Kumar, A. Bioenergy plantations:A model system for restoration of semi arid regions. In: Biomass for energy andenvironment, P. Chartier, G.L.Ferrero, U.M. Henius, S.Hultberg, J. Sachau,M.Wiinblad, eds, Elsevier Science U K. ; l996.

Kumar, A. Economics ofbioenergy in developing countries. In: Bioenergy 84 Vol.4, Bioenergy indeveloping countries. , London + Elsevier Applied Science Publishers; 1984.

Kumar, A. Prospects of raisinglatex bearing plants in semi-arid and arid regions of Rajasthan. In: Biomassfor Energy and Industry (Eds G. Grassi, G. Gosse and G. dos Santos)

London; 1990.

Kumar, A. 'Laticifers aspotential bioremedients for wasteland restoration', J. Environment &Pollution 1994;  1:  101-104.

Kumar, A. 'Cultivation ofhydrocarbon yielding plants in Rajasthan as an alternative energy source', J.Environment&Pollution, 1995;2:  67-70.

Kumar, A. Biomass energy cropsof semi arid regions of India and their energy potential. In: Biomass forEnergy and Industry, C A R M E N, Germany; 1998.

Kumar, A. Hydrocarbon yieldingplants and future prospects of biotechnological approach. In : Recent Advancesin Biotechnology, New Delhi + Panima Publisher; 2000.

Kumar, A. 'Bioengineering ofcrops for biofuels and bioenergy.  In:From soil to cell: A broad approach to plant life. Eds. Bender, L. and Kumar,A. (Giessen  + Electron. LibraryGEB),.http://geb.uni-giessen.de/geb/volltexte/2006/3039/pdf/FestschriftNeumann-',2001a: 1-16.  1-5.

Kumar, A. 'Conservation andutilization of Herbal drugs to protect them from extinction = an urgent need',in Proceedings International Forum forTraditional Medicine., Toyama, Japan, 2001b; 281-284.

Kumar, A. Bioengineering ofcrops for biofuels and bioenergy.In: Kumar, Ashwani and S. Sopory (eds) RecentAdvances in Plant biotechnology, I.K. International. New Delhi; 2008.

Kumar, A. Biofuel resources forGreen House Gas Mitigation and Environment Protection. In:  Agriculture Biotechnology, Jaipur +AvishkarPublishers; 2011.

Kumar, A. and Garg, J. 'Effectof organic manures on growth and hydrocarbon yield of Euphorbia lathyris L. J.'Environment&Pollution, 1995;  2: 207-210.

Kumar, A., Johari, S. and Roy,S. 'Production and improvement of bioenergy sources.' J. Indian. Bot. Soc., 1995; 74A:  233-234.

Kumar, A. and Roy, S. 'Biomassresources of semi arid regions: Production and improvement of wood energysource. In: Biomass for energy and environment (P. Chartier, G.L.Ferrero, U.M.Henius, S.Hultberg, J. Sachau, M.Wiinblad, eds.) ', Elsevier Science, U.K, 1996: 721-724.

Rani, A. and Kumar, A. 'Effectof edaphic factors on the growth and physiology of Pedilanthus tithymaloidesVar. Green', Journal of Environment and Pollution, 1994;  2:  5-8.

Rani, A. and Kumar, A.'Micropropagation of Pedilanthus tithymaloides var. Green, a hydrocarbon yieldingplant. ' J. of Phytol. Res, 19947:  107-110.

Rani, A., Roy, S. and Kumar, A.Eds. Grassi, G., Gosse, G. and Santos, G. Influence of morphological andenvironmental factors on growth and hydrocarbon yield in Calotropis procera.In: Biomass for Energy and Industry. , London + Elsevier Applied Science; 1990.

Rani, A., Roy, S. and Kumar, A.(Eds.H.L. Sharma and R.N. Sharma)Effect of salinity stress or growth andhydrocarbon yield of Pedilanthus tithymaloides variety Green (Linn.) Point. In:Proc. Bio-Energy for Humid and Semi-humid Regions New Delhi; 1991.

Roy, S. Growth and productivityof non conventional energy sources: J.curcas In: Biomass for energy andenvironment. (P. Chartier, G.L.Ferrero, U.M. Henius, S.Hultberg, J. Sachau,M.Wiinblad, eds.), Elsevier Science, U. K; 1996.

Roy, S. and Kumar, A. 'Prospects of wood energy production in semi-arid and arid regions of Rajasthan.In: Proc. Biomass for Energy and Industry. (G. Grassi, G. Gosse and G. dasSantos, eds.)', Elsevier Applied Science,1990;  London:  2.1153-2.1156.

Roy, S. and Kumar, A. Nonedible oil and seed plants as source of energy and biodiesel.  In: Biomass for energy and Industry. EdsKopetz, H. et. al., , Germany + Carmen; 1998a.

Roy, S. and Kumar, A. Nonedible oil and seed plants as source of energy and biodiesel. In: Biomass forenergy and Industry. (Kopetz H. et. al., eds.), CARMEN. Germany; 1998b.

Staff, F. 'Development ofBiodiesel activity in France. In: Biomass for energy and industry. (H. Kopetzet al. ,eds.)', CARMEN Germany, 1998:  112-115.

Wirsenius, S. 'The biomassmetabolism of the food system: A model-based survey of the global and regionalturnover of food biomass', Journal of Industrial Ecology 2003;  7: 47-80.

Wort, D. 'In: The Physiologyand Biochemistry of Herbicides (Ed.) L.J. Audus', Academic Press, London, 1964: 291.