Page 286 - Low Temperature Energy Systems with Applications of Renewable Energy

272 Low-Temperature Energy Systems with Applications of Renewable Energy

Fig. 7.12 HOST microferm biogas installation, Angers, France [18].

The technology of methane fermentation in a bioreactor requires compliance with
the limits of temperature regimes, and the intensification of heat exchange between the
heater and the substrate through mixing. A facility in Angers, France is shown in
Fig. 7.12, and a diagram for the simulation of energy-saving heat and mass exchange
processes in a bioreactor with a mixing device is shown in Fig. 7.13.
The mass exchange process (conservation of mass) in the bioreactor is described by
the formula:

0
m sub ¼ m sub þ m g (7.2)
where m sub is specific mass of substrate [M sub e substrate mass in the biogas plant]
0
loaded into the reactor, kg; m sub is mass of the substrate after processing in the

Fig. 7.13 System for the simulation of energy-saving heat and mass exchange processes. 1,
thermal insulation case; 2, substrate; 3, heater; 4, gas pipeline; 5, waste heat exchanger; 6, main
circuit of secondary heat transfer recirculation; 7, biogas storage tank; 8, pump; 9, safety valve;
10, mixing device; T b , bioreactor temperature; T out , temperature at the outlet of the bioreactor.