Wet fermentation

ZORG™ biogas plants produce biogas and bio-fertilizers from biological wastes and energy crops by means of oxygen-free wet fermentation (wet anaerobic digestion). An industrial biogas plant is a large construction project which consists of 70-80% high capital equipment. The main part is closed reactors (or digesters, methane tanks, bioreactors) made of reinforced concrete or glass-fused-to-steel tanks.

Liquid biological wastes are pumped to the biogas plant via a pipeline. They initially come to the primary tank, where they are homogenized and heated (sometimes cooled) to the required temperature.

Biogas plant interactive scheme. Please click to run

Solid wastes are loaded to the digester via a special screw auger. The digesters are heated to the correct temperature by the heat-transfer system.

Microorganisms do all the work of waste fermentation, and are injected into the digester only once during the biogas plant start up. The end products after digestion are biogas and bio-fertilizer.

Biogas is stored within a gas holder. Inside the gas holder, pressure and biogas composition is evened. From the gas holder, biogas is constantly supplied to the gas or diesel-gas combined heat and power system by means of the gas supply system. The gas supply system has an integrated system for biogas drying, hydrogen sulphide removal and gas conditioning. Big biogas plants are equipped with biogas flares. If plant owners do not need to generate electricity, but gas as a final product, the biogas plant can be equipped with CO2 removal and bio-methane upgrading systems.

Biogas plant interactive scheme. Please click to run

Digested biomass is a fertilizer. The liquid fraction can be separated from the solid fertilizer fraction with the help of a separator and is stored in a fertilizer storage tank.
The complete biogas system is controlled by an automation system. 1 man-hour per day of technical staff input is enough to ensure a smooth operating biogas plant.

Biogas plant interactive scheme. Please click to run