By Ashwani Kumar
| March 7th 2012 05:06 PM | Print
• Climate change is any long-term significant change in average temperature, precipitation and wind patterns. Climate change takes place due to emissions of greenhouse gases which causes environmental damage to any given area. .Carbon dioxide (CO2) is the most important greenhouse gas and increasing the use of biomass for energy is an important option for reducing CO2 emissions. Photosynthetic organisms use solar energy to generate reducing equivalents and incorporate atmospheric CO2 into organic molecules. This helps in carbon sequestration. First generation biofuels - ethanol and biodiesel are predominantly produced from corn kernels, sugarcane or soybean oil rape seed oil, palm oil etc.
• During the decades from 1980.s work was initiated on petro-crops following the work of Melvin Calvin from California agrotechnology for some of the Euphorbia spp were optimized. Subsequently work on Jatropha has been carried out for the last 20 years at our Energy Plantation Demonstration Project supported by Govt of India at University of Rajasthan, Jaipur. However use of Jatropha for oil and biodiesel produced discussions on food vs fuel .Arguments were made that even if non edible oil yielding crops were raised on wastelands the ecological balance was disturbed in the long run. Recently in a meeting of German Plant Nutrition Society issue was raised of nitrogen imbalance in soil and ground water. These controversies paved way for the next generation biofuels. Currently, cellulosic biofuels and algal biodiesels are prominent biological approaches to sequester and convert CO2. However another biofuel feedstock, lignocelluloses—the most abundant biological material on earth is being explored. Lignocelluloses is 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. Second and third generation biofuels require altering host material by metabolic engineering for entire product and developing new enzyme systems. Industrial application of biofuel inclusive of related bio products of commercial value from fourth generation products is being adapted on large scale.. Carbon captured in cellulosic biofuels and algal biodiesels are prominent biological approaches to sequester and convert CO2.Lipid productivity of many algae greatly exceeds that of the best cellulosic ethanol production. Another approach is direct conversion of CO2 to fuels or chemicals. Biofuels will reduce greenhouse gas emissions, promote energy independence, and encourage rural development.
First efforts to cultivate hydrocarbon producing plants for fuel production were made by Italians in Ethiopia and French in Morocco Later on Calvin and his collaborators have revived the idea again and have advocated the study of petro-crops as a possible feedstock for petroleum like materials.
Worldwide energy consumption is projected to grow by 59 percent over the next two decades, according to International Energy Outlook 2001 (IEO 2001), released by US Energy Information Administration EIA. One half of the projected growth is expected to occur in the developing nations of Asia ( Including China, India and South Korea) and in Central and South America, where strong economic growth is likely to spur demand for energy over the forecast period. Renewable energy use is expected to increase by 53 percent between 1999 and 2020, but its current 9 percent share of total energy consumption is projected to drop to 8 percent by 2020. Oil currently accounts for a larger share of world energy consumption than any other energy source and is expected to remain in that position throughout the forecast period. World oil use is projected to increase from 75 million barrels per day in 1999 to 120 million barrels per day in 2020.
Biomass resources are potentially the worlds largest renewable energy source- annual terrestrial biomass yield of 220 billion oven dry tonnes. Biomass conversion to fuel and chemicals is once again becoming an important alternative to replace oil and coal. Biodiesel from the rape seed oil methylester (RME) by farmers cooperative has production of 2000 t RME per year. A large facility 15000 t RME per year is located at the oil mill at Bruck/Leitha in Austria. RME is excellent substitute for diesel. Already European countries mainly Italy, Germany and Austria are leading in Biodiesel production nearing 500,000 tons in 1997 out of which 2,50,000 was produced in France.( Statt, 1998) The production capacity of biodiesel in Germany was fully utilized in1997, the sold quantity amounting to roughly 100,000 t (Groenen,1998). The technologies for producing bio-oil are evolving rapidly with improving process performance , larger yield and better quality products. The challenge is to develop a process technology which can cope with the significant variation in the composition of the raw material. Another line of action is Camelina sativa . This plant was a traditional oilseed in Europe. It is considered “low input high yield” plant which could enhance the environmental aspect of biodiesel. However it has higher Iodine number (160).
Now it is not as a result of the oil crisis but due to global warming . Carbon dioxide emissions 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. The Kyoto conference agreement last year is not far reaching but indicates the role clear energy sources will play in future. Biomass is renewable, non pollutant and available world wide as agricultural residues, short rotation forests and crops . Thermochemical conversion 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 sustainable development of large areas of the world is today one of the greatest challenge . How will it be possible to provide the means for improving the socio-economic conditions of the increasing population in Developing countries, a large part of which lives in villages and rural areas of Asia, Africa and South America. Biomass currently supplies about a third of the developing countries energy varying from about 90 percent in countries like Uganda, Rwanda and Tanzania to 45 percent in India, 30 percent in China and Brazil and 10-15 percent in Mexico and South Africa. Tropical deforestation is currently a significant environmental and development issue. The annual tropical deforestation rate for the decade 1981-1990 was about 15.4 million ha (Mha). According to some estimates the forest cover is 64.01 Mha accounting for 19.5 percent of India’s Geographic area. At present there is hardly 0.4 percent forest cover below 25 cm rainfall zone and 1.3 percent above 30 percent. Since the annual photosynthetic production of biomass is about eight times the worlds total energy use and this energy can be produced and used in an environmentally suitable manner and mitigating net CO2 emission, there can be little doubt that the potential source of stored energy must be carefully considered for future energy need. The fact that nearly 90 percent of the worlds population will reside in developing countries by about 2050 probably implies that biomass energy will be with us forever unless there are drastic changes in the world energy trading pattern.
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.
Current commercial and non-commercial biomass use for energy is estimated at between 20 and 60 EJ/a representing about 6 to 17 percent 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 percent or less.
Global land availability estimates for energy crop production vary widely between 350 and 950 million hectares (Alexandratos, 1995). An energy potential of about 37.4 EJ/a is estimate based on country specific biomass yield and an average land availability The worldwide technical biomass energy potential is then estimated at about 104 EJ/a corresponding to approximately one third of the global 320 EJ/a primary energy consumption of oil, gas and coal ( BP-Amoco 1999).
Bio-oil consortium of UK received huge grants ( 1.16 million pounds) to enable commercial production and testing of integrated Bio-Oil and electricity generating plant. UK energy minister Peter Hain ascribed “ high priority to research and development of sustainable energy sources “. Commercial processing plants for the medium scale production of biodiesel from inter-esterification of triglycerides have been developed in France, Germany(CARMEN), Austria(ENERGIA Biodiesel Technology) USA (Ensyn Group Inc.) and in EU (Eubia ).
Biomass energy is experiencing a surge in interest in many parts of the world due to greater recognition of its current role and future potential contribution as modern fuel in the world energy supply, its availability versatility and sustainable nature; a better understanding of its global and local environmental benefits, perceived potential role in climate stabilization, the existing and potential development and entrepreneurial opportunities. Technological advances and knowledge which have recently accumulated on many aspects of biomass energy; greater understanding of the possible conflict of food versus fuel etc. A recent World Bank report concluded that “Energy policies will need to be as concerned about the supply and use of bio-fuels as they are about modern fuels.. (and) they must support ways to use bio-fuels more efficiently and in sustainable manner ( World bank, 1996)