Continuous stirred-tank reactor
A frontal loader delivers substrates into a hopper where the inputs are crushed and fed to the horizontal auger. Next, the substrates are transported to the vertical auger.
Supply of substrates
Substrates are fed into the reactor by vertical and inclined augers.
The target temperature inside the reactor is maintained with heating pipes on the inner reactor walls.
Substrates are constantly mixed with inclined and submersible mixers.
Anaerobic bacteria digest the substrates, producing biogas.
Sulfur is removed by means of a biofilter. To create the local aerobic conditions for sulfur-eating bacteria, air is supplied.
Biogas is collected and stored in a gas-holder on top of the reactor. Then it is dried, compressed by a gas blower, and pumped for combustion
The CSTR biogas technology (Continuous Stirred Tank Reactor) is simple and easily recognizable.
Distinctive features are the diameter of the biogas reactor is greater than the height, heating by pipes on the reactor’s walls, a flexible gasholder above the reactor, sulfur removal by a biofilter from air in the center of the reactor, mixing with inclined and submersible mixers. Biogas reactors are made of either reinforced concrete or bolted steel panels.
Moisture in a well-functioning CSTR biogas reactor is 93-97%. The organic dry matter load per m³ of reactor is 2-5 kg per day. Fermentation occurs in the mesophilic mode of +35°C to +41° С.
The technology is most often used for processing manure, dung and silage. A biogas plant with CSTR technology is often referred to as a “farm-style”. It is easy to maintain, which is especially important in rural areas, but less effective than other technologies.
- load of organic dry matter (ODM) 2-5 kg/m³ of the biogas reactor per day
- heating by pipes on the walls of the reactor
- mesophilic mode from +35 °C to +41 °C
- solids content in the reactor 4-10%
- sulfur removal using a biofilter