biochemistry of biohydrogen production

1. BIOHYDROGEN PRODUCTION
MITAL CHANDEGARA
BIOTECHNOLOGY
16

2. CONTENT
• Introduction
• Why hydrogen?
• Methods of hydrogen production
1) Physicochemical
2) Biological
• Ongoing projects in India
• Reference

3. INTRODUCTION
• Biohydrogen
• Use of fossil fuel is increase (transportation , power & heat
generation)
• Increased CO₂ level
• Global warming ( climate change )
• Alternative option (environment friendly)

5. • Most abundant element on the earth (H₂O)
• Simplest one (1e +1p)
• Highest energy content(122kJ/g , 2.75 times higher
than HCs)
• Clean fuel (no green-house gas emission)
• Combustion of H₂ produce water
• Globally accepted as environmentally safe energy
recourse

6. Hydrogen production
Physicochemical Biological
1) Steam reforming of light HCs
2) Thermal cracking of natural gas
3) Partial oxidation/gasification of
heavier HC or coal
4) Electrolysis of water
1) Dark fermentation
2) Photo fermentation
3) Bio-photolysis
4) Integration of dark + photo
fermentation

7. NEED OF BIOHYDROGEN
• Uses of hydrogen in different industries
(fertilizer = ammonia, oil refinery = hydrotreatment of crude oil for
sulphur removal)
• Global H₂ demand fulfilled by 1st 3 Pc method
(major drawback - high energy intensive & emits greenhouse gases)

8. DARK FERMENTATION
• Either obligate or facultative anaerobes are capable to utilize various
organic material as a substrates
• Occurs in ab of oxygen
• Facultative anaerobes like Enterobacter , Citrobacter
• Obligate anaerobes like clostridium

9.  In Enterobacter…..
PFL :pyruvate
formate lyase
FHL :formate
hydrogen lyase

10. In clostridia…..

11. Advantages:-
• Produce valuable metabolites as by-products
• No requirement of light & oxygen
• Variety of carbon sources can be use
Limitations:-
• Produce gas mixture hence further purification require
• Accumulation of acid leads to pH drops & inhibit H₂ synthesis
• Relatively lower energy yield

12. PHOTO FERMENTATION
• Photosynthetic bacteria (PNS bacteria such as Rhodopseudomonas &
Rhodobacter )
• Anaerobic condition
• Photosynthetic pigments
• Short chain organic acid utilization
• Light as source of energy
• Nitrogenase

14. Advantages:-
• No release of O₂ (no E inhibition)
• High H₂ yield efficiency
• Uses wide spectral of light energy (450-590-visible ,800-875nm nIR)
Limitation:-
• Limited availability of organic acid
• Practical application (SA/V)
• High construction cost

15. BIOPHOTOLYSIS
• 2 types
1) Direct biophotolysis
2) Indirect biophotolysis

16. 1) DIRECT BIOPHOTOLYSIS
• Green algae
• Hydrogenase
• PS II split water into O₂ & H+ ion
Advantage:- Substrate – water (easily available)
Limitation :- O₂ inhibit hydrogenase

18. 2) INDIRECT BIOPHOTOLYSIS
• Cyanobacteria
• Vegetative cell & heterocyst
• Nitrogenase

19. OPPP:- oxidative
pentose phosphate
pathway
(CH₂O) :- saccharide

20. INTEGRATION OF DARK & PHOTO FERMENTATION
Dark
fermentation
Photo
fermentation

26.  Introduction to biofuels by D. M. Mousdale
 Production of biological hydrogen in india by Prof. Y K Yadav, Dr sachin kumar
& Raman Rao
 Review on recent developments in biological hydrogen production processes
by Debarata Das , Namita Khanna, T. Nejat Veziroğlu
 Review on outlook of fermentative hydrogen production techniques :- An
overview of dark, photo and integrated dark-photo approach to biomass by
Puranjan Mishra, S. Krishna, S. Rana & Lakhveer singh
 Ministry of new & renewable energy