bio-hydrogen the future fuel

Bio Hydrogen The Future Fuel: 

Bio Hydrogen The Future Fuel -Abhisek Dwivedy Rakesh Majhi National Institute of Science Education & Research

Slide 2: 

F U E L C E L L FUEL CELLS CONVERT HEAT OF COMBUSTION DIRECTLY INTO ELECTRIC ENEGRY WHEREAS CONVENTION TURBINES LOSE ALMOST 60% OF THAT ENERGY WHEN IT CONVERTS TO MECHANICAL AND THEN TO ELECTRICAL ENERGY

Slide 3: 

Key Facts About Hydrogen as Fuel Can be easily stored and transported Highly combustible and can be used as fuel 1g on combustion provides 30000cals as compared to gasoline that gives only 11000cals End products being water only causes no environmental hazard Can be easily produced from water using biological agents Microorganisms like bacteria and leguminous crops Biologically produced hydrogen is known as biohydrogen Employs two main biological pathways of biohydrogen production- hydrogenase mediated biophotolysis and nitrogenase mediated biophotolysis

Slide 5: 

Hydrogenase Mediated Pathway Photosynthetic bacteria like Chlorella, Chlamydomonas, Spirulina, Microcystis carry out photolysis of water during photosynthesis and produce molecular hydrogen using water as raw material. H2O  O2 + H+ + e-…….photolysis H+ + H+ + hydrogenase  H2 Hydrogenase being sensitive to oxygen, the production of molecular hydrogen reduces on higher oxygen concentrations This problem can be successfully tackled with using separators in bioreactors used for micro culture which selectively take oxygen out using special oxygen scavenging microorganisms

Slide 6: 

HYDROGENASE MEDIATED H2 PRODUCTION

Slide 8: 

Nitrogenase Mediated Hydrogen production Nitrogen fixing bacteria like Anabaena, Nostoc and leguminous plants produce molecular hydrogen as a byproduct during nitrogen fixation Annually a soybean field of a hectare size loses 30 billion cubic meters of molecular hydrogen Nitrogen fixing bacteria in a hectare field lose almost 3 times hydrogen as compared to leguminous plants N2 + 8H+ + 8e- + nitrogenase  2NH3 + H2 Nitrogenase being also sensitive to oxygen, the hydrogen production lowers on high oxygen concentrations In leguminous plants, leghaemoglobin acts as an oxygen scavenger In free living micro organisms special oxygen scavenging molecules and radicals are coupled using genetic engineering

Slide 9: 

NITROGENASE MEDIATED H2 PRODUCTION

Slide 11: 

CHLORELLA CULTURE FOR H2 ANABAENA CULTURE FOR H2

Slide 12: 

Fermentative hydrogen production a less efficient way • A dark anaerobic process by which bacteria and yeasts gain energy from organic matter, like Rhodospirullum, Methanogens etc • Requires wet, carbohydrate-rich biomass substrates • Produces fermentation end products -gases, acids and alcohols • property of many species of bacteria, particularly clostridia • carbohydrates are favoured substrate • involves hydrogenase • H2 yield depends on fermentation products C6H12O6 + 2 H2O  2CH3COOH + 2CO2 + 4 H2 Very less economical in terms of productivity

Slide 13: 

HALOBACTERIUM CULTURE FOR H2 PRODUCTION

Slide 14: 

Biocells in energy production Two species of Halobacterium, H.halobium and H.Curtirubrum are highly halophilic. In saline (anaerobic) environment the bacteria incorporate a purple pigment known as bacteriorhodopsin(bR) to its cell membrane in sunlight. Bacteriorhodopsin is constituted by 75%proteins and 25%lipids and occupies 50% area of total cell surface. It has 3 synergistically acting molecules which function normally even after death of the bacteria provided the pigment is not disorganized. It has two photointerconvertible forms namely bR 560(dark) and bR570(light). During photoreaction cycle bR molecules take up protons in inner surface of the membrane and release them on outer surface, thus developing proton gradient/electric potential (about 200mV per molecule) across the membrane. Each bR molecule pumps about 200H+ per second in light, thus pump 24 X 1000000 protons per sheet per second. The bR molecules can be used in Biocells to generate electric potential on illumination.

Slide 15: 

Needs and Challenges for Biohydrogen Production Efficient hydrogenase and nitrogenase having oxygen resistant features Wide range regulatory pathways controlled by broad spectrum hydrogenase and nitrogenase Efficient bioreactors containing oxygen scavenger molecules/radicals or micro organisms Genetically engineered microorganisms for oxygen tolerance Mixed micro flora for enhanced production and yields Direct supply of biohydrogen to Fuel Cells Efficient fuel cells Efficient storage and transportation Enough capital and labor in research field for enhancement in production and use

Slide 16: 

For further information contact: Rakesh Majhi (+919337269728)‏ Abhisek Dwivedy (+919861512235)‏ Thank You