IIT KGP Researcher turns wastewater into fuel

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Hydrogen fuel derived from industrial wastewater may be driving your cars soon or electricity from biohydrogen light villages in India, say scientists at IIT Kharagpur. This will serve dual purposes: hydrogen production and bioremediation of the wastewater. Hydrogen is found suitable as a fuel in vehicles and all the major automobile companies are in competition to build a commercial car and market hydrogen fuel automobiles in near future. The humongous rise in world energy consumption expected by 2030, would require an alternative fuel resource with highest energy density. Hydrogen fulfils this criterion. Hydrogen is being considered as a fuel for the ‘‘future’’ because it has the highest energy density of 143 kJ/g considering water as a product. 
 
Speaking to the audience in the ‘International Conference on “21st Century Energy Needs – Materials, Systems and Applications 2016’, Prof. Debabrata Das, faculty at the Dept. of Biotechnology at IIT Kharagpur, pointed out that at present, approximately 95% of commercially produced hydrogen comes from carbon-containing raw materials, primarily fossil in origin. Steam reforming of natural gas, gasification of coal and electrolysis of water are some of the conventional hydrogen production processes. However, these processes are highly energy-intensive and not always environmentally benign. Given these perspectives, biological hydrogen production assumes paramount importance as an alternative energy resource. “Hydrogen production from renewable energy would result in a permanent solution of energy system. With fossil fuel reserves depleting, hydrogen holds the promise to provide clean and eco-friendly energy supply to meet the growing energy needs for transportation and power generation in the coming years.” said Prof. Das. 
 
Although hydrogen can be produced from fossil fuels and biomass, IIT Kharagpur scientists are in the process of generating the gas from distillery wastewater with a vision of 'waste to energy'. The researchers are using dark fermentation process under which bacteria can work both in the presence and absence of light. "We have isolated several organisms - one from the leaf of a particular plant and one organism from high oil containing soil. All are giving very good results," Prof. Das said. Methane would also be produced from the spent medium of biohydrogen generation process. One patent has been awarded on the biohydrogen production process. This project is funded by the Ministry of New and Renewable Energy (MNRE), Govt. of India. The Ministry featured the project in its Akshay Urja publications.
 
Presently, 10 m3 bioreactor has been installed to produce hydrogen continuously from the organic wastes like distillery effluent. “This gas does not content H2S. So, it can be used in the fuel cell directly for the generation of electricity of 52 kwh. This may be used for lighting a village in India” added Prof. Das. 
 
The cost of production would be a critical factor in getting the technology move from lab to factories. Scientists are also comparing the solar hydrogen energy system and the synthetic fossil fuel system by taking into consideration production costs, environmental damages and utilization efficiencies. The results indicate that the solar hydrogen energy system is the best energy system to ascertain a sustainable future, and it should replace the fossil fuel system before the end of the 21st Century.
 
MNRE in its National Hydrogen Energy Road Map has projected that one million hydrogen-fuelled vehicles would be on Indian roads and 1000 MW aggregate hydrogen-based power generating capacity to be set up in the country, both by 2020. Large-scale production of hydrogen gas for commercial use is now at R&D stage in India. Long lasting, light and clean metal hydride batteries are already commercial for laptop computers. According to experts, storage would be a major challenge as hydrogen has a very low volumetric energy density and requires large space to store.