BIOHYDROGEN PRODUCTION Hydrogen gas is an important alternative

BIOHYDROGEN PRODUCTION

Hydrogen gas is an important alternative fuel that is sustainable and environment friendly. Because with combustion only water and energy is formed. The fuel with the highest energy density among the fuels (143 k. J / g) Hydrogen is produced by physical, chemical and biological methods.

Today, 96% of hydrogen is produced from fossil fuel sources 48% natural gas, 30% from oil 18% from coal, 4% from water electrolysis Although hydrogen production by biological way constitutes a small portion, it is thought that this will increase with the developed techniques.

Fuel properties of hydrogen Hydrogen can be carried anywhere easily and safely can be used in industry, homes and vehicles inexhaustible, clean, easily converting to heat, electrical and mechanical energy, carbon-free, is an economic and light source of energy.

Biological production of hydrogen occurs through two main mechanisms: Photobiological production: photosynthetic microorganisms such as algae or photosynthetic bacteria are used in this process. Fermentation: Facultative anaerobes and obligate anaerobes, hydrogen-producing microorganisms, are used in this process.

There are several technologies used for the production of biohydrogen. These are; Direct biophotolysis Indirect biophotolysis Photo-fermentation Hydrogen synthesis by water-gas shift reaction Anaerobic digestion

Clostridium pasteuranium, C. butrycum, C. beijerinkii are high hydrogen producers; C. propionicum is a weak hydrogen producer.

Important enzymes Biological hydrogen production reactions depend on hydrogenase or nitrogenase enzymes that catalyze the reduction of protons.