Organic Waste Recycling

Biofuels production 155

Figure 4.3 Biomethanation of organic wastes (Brown and Tata 1985)

II Acetogenic bacteria

Organic wastes (Carbohydrates, proteins, fats)

Organic acids, alcohols and other neutral compounds

Acetogenic dehydrogenation Acetate

Acetegenic hydrogenation

Reductive methane formation

Acetate decarboxylation

Methane + Carbon dioxide

Hydrogen + Carbon dioxide

Hydrolysis and fermentation

I Acid-forming bacteria

III Acetoclastic bacteria

IV Hydrogen-utilizing methane bacteria