BIOTECHNOLOGY - V. H. Herasymenko - 2006

Part II. Specialized Biotechnologies

Chapter 22. BIOTECHNOLOGIES FOR WASTE MANAGEMENT AND BIOCONVERSION IN THE AGRO-INDUSTRIAL COMPLEX

22.3. UNCONVENTIONAL METHODS. BIOTECHNOLOGY OF BIOGAS PRODUCTION VIA ANAEROBIC WASTE DIGESTION

22.3.4. Fractions Formed During Biomethanogenesis

The schematic flowchart of biogas production includes the following stages:

1) biomass accumulation and preparation;

2) biomass transformation into biogas (direct methane Fermentation);

3) rational utilization of methane fermentation products (biogas and organic-mineral fertilizers).

The anaerobic fermentation of biomass from any source yields the following fractions:

1) biogas (a gas mixture);

2) organic matter not decomposed by microorganisms (solid fraction or sludge) with a moisture content of 65-70 %;

3) liquid fraction or supernatant.

Being lighter, the biogas generated in the fermentation chamber accumulates above the fermenting mass, from where it is piped into a gas holder (gas reservoir).

The Separation of the digested biomass into Solid and liquid fractions can be carried out using a centrifuge or vibrating screen.

On average, 1 kg of organic matter that is 70 % biodegraded yields 0.5 kg of biogas, 0.2 kg of Water, and 0.3 kg of undecomposed residue or sludge.