|Biofuels: Prospects, Challenges, and Commitment|
Every year, August 10 is celebrated as International Biodiesel day. Way back in 1850, scientists named E Duffy and J Patrick designed the first diesel engine. Following this, Rudolf Diesel built the prime model of diesel engine which was for the first time powered on August 10, 1893 in Germany. Since then, this day is celebrated as International Biodiesel Day. It is believed that Rudolf Diesel designed this engine in a manner that it could run on peanut oil. During the 1920s and 1930s, countries across the globe - be it countries in Europe, China, Brazil, Japan, Argentina, and so on, were using animal fat or vegetable oil as fuels. Thereafter, discovery of fossil fuel, however, eliminated the use of vegetable oils as engine fuels. Needless to say the efficiency of petroleum-based fuels is far higher than the biodiesel and also the ease of which they are available led to their global acceptance. It is well documented that petroleum reserves are unevenly distributed across the globe and have limited availability, with the danger of running out.
Over the years, global oil demand has increased significantly and as a result fossil-based reserves are depleting at a faster rate. Apart from these, associated greenhouse gas (GHG) emissions from burning of fossil-based fuels also raised great concern for climate security. The environmental costs in terms of emissions through burning of petrol/diesel is too high and have damaged the globe beyond repair. Energy security and climate security issues, made it imperative for the countries to explore for alternate renewable energy resources that do not rely on conventional resources.
Countries such as India being the fastest growing petroleum oil consumer, must take urgent steps to develop renewable energy forms due to its limited fossil-based reserves, heavy imports, resulting in negative economic implications. The increased GHG emissions are further adding to the woes due to climate change, which otherwise also is expected to negatively hit this part of the globe.
To address the issues of energy security and to protect the environment from detrimental impact of GHGs, the National Biofuel Policy made in 2009 by the Ministry of New and Renewable Energy (MNRE), Government of India, had a goal to regulate biofuel marketing in the nation in accordance with standard legal guidelines. Eventually, the MNRE proposed comprehensive national biofuel policy with an indicative target of 20 per cent blending of biofuel (bioethanol and biodiesel) by 2017. This policy aimed at use of non-edible feedstock and development of more efficient second-generation biofuel production technologies. Moving forward towards production of clean energy, recently in 2018 the Government of India announced national policy on biofuel that aims at cutting down of oil imports. This policy expanded the scope for use of various raw materials for bioethanol production and encourages on setting up of supply chain mechanisms for biodiesel production from non-edible feed, used cooking oil, including short gestation crops.
To achieve the national biofuel policy goal, the Department of Biotechnology (DBT), Government of India, apart from their initiatives in many path-breaking research activities is supporting major research in the areas of biofuel and is leading mission innovation programme since 2015 with 25 countries as partners. The project is a global initiative for innovating technologies to mitigate impact of climate change; develop clean energy alternatives that can be replicated at large scale and affordable to the consumers, thus creating green jobs and many commercial opportunities. The launch partner countries included China, India, the USA, Indonesia, and Brazil, representing 75 per cent of the world's CO2 emissions from various sources. Further, DBT has set up five Centers of Excellence in bioenergy with leading institutions of the country.
These centres are:
DBT-TERI Centre of Excellence is aimed towards development of technologies for production of advanced biofuels; ‘algal biodiesel, pyrolytic oil, biohydrogen; and Bio-commodities; ‘2,3 Butane diol, acrolyn, high value pigments, bio-plastic, aqua feed and animal feed’, from 3rd generation feed (algae and aquatic macrophytes) in a bio-refinery approach. This is the first biorefinery project established by DBT at TERI with a goal to achieve the zero waste discharge by effectively utilizing the co-products of different processes as feed to produce value-added bio-products that would aid in closing loop.
So far, economic viability is a major constraint for advanced biofuel production, thus limiting its commercialization. Hence, it is essential to effectively use the co-products as feed for generation of high value bio-commodities to make the overall process cost competitive.
The concept of integrated production of advanced biofuels and bio-commodities is based on the multidisciplinary research expertise of TERI, including previous successes in establishing large-scale photo bioreactor for year-round production of high lipid containing algal strain, pilot scale biohydrogen production through dark fermentation process from sugarcane blackstrap molasses, and pyrolytic bio-oil production.
Under this centre’s activity, TERI would set up a 100,000 L algal production system at Mumbai coastal location utilizing sea water, the pertinent water source in India for large-scale cultivation of marine microalgae. The system would be a scale up of the sunlight distribution-based photo-bioreactor developed earlier at TERI in pilot scale (1800 L and 10,000 L capacities). This has demonstrated 1.5-3.0 times higher areal productivities compared to standard systems. Wet algal slurry will be processed for lipid recovery for subsequent conversion to biodiesel.
The deoiled algal biomass after fuel lipid recovery would be explored further for fuel, bio-oil, and biohydrogen through employment of pyrolysis process and dark fermentation process. Further aquatic plant biomass (water hyacinth and Azolla) would also be employed as new second-generation feedstocks for production of hydrogen through biological route by using a bacterial strain isolated at TERI that could feed on both pentose as well as hexose sugars. The second generation biohydrogen production process would be developed in pilot scale.
To make the overall process cost-competitive, the co-product - crude glycerol, by-product from biodiesel production would be used as feedstock for microbial production of 2,3-butanediol (specialty industry platform chemical) and for the development of acrylate polymers (acrolein platform chemical-based) as value-addition products. The char by-product from the pyrolysis streams would be evaluated for the development of activated carbon and its high-end use applications. Algal biomass would be also be explored for production of high value compounds; Omega-3 fatty acids, lutein, β-carotene and astaxanthin, production of cellulose nanocrystals for application in bioplastic production, formulation of aqua feed and animal feed from deoiled algae biomass’, in a bio-refinery approach.
Comprehensive techno-economic analysis, environmental assessment and socio-economic assessment would be carried out covering the entire range of the integrated project components.
Dr Vibha Dhawan, Distinguished Fellow, TERI; and Dr Sanjukta Subudhi, Senior Fellow, DBT-TERI Centre of Excellence in Advanced Biofuel & Biocommodities and Environmental & Industrial Biotechnology Division, TERI, New Delhi.