Biogas stations
at alcohol factories

For alcohol plants, we recommend industrial CSTR reactors with a vertical axial agitator, metal roof and separate gas holder. This solution is optimal for large volumes of distiller’s grains and stable continuous loading. Due to the low organic load, digesters are usually not required, but in the case of co-fermentation (e.g. with manure), it is advisable to provide them to increase gas yield and process stability.

No additional mechanical preparation is required before feeding into the reactor: the distiller’s grains are fed directly into the fermenter. It is essential to adjust the pH, as distiller’s grains have an acidic reaction — an alkali solution is fed into the receiving tank or directly into the reactor. The temperature regime is taken into account separately: the distiller’s grains leave the plant at a temperature of approximately 70°C, so a cooling circuit is provided if necessary. A defoamer and microelements (for monosubstrate) are also integrated into the fermenter.

Biogas requires desulphurisation and drying. Due to the use of sulphur-containing reagents in alcohol production, it is advisable to use biological desulphurisation in scrubbers, which effectively reduces H₂S and protects energy equipment. Drying is a mandatory stage in gas preparation.

The priority option for biogas use is electricity generation (CHP) or feeding it into a boiler to produce steam for the plant’s technological needs. Upgrading to biomethane is only possible if it can be proven that the distiller’s grains are waste (and not feed), but regulatory restrictions and the complexity of obtaining a “green” premium limit the economics of such projects.

All nodes are integrated into SCADA and a commercial accounting system with control over the supply of distiller’s grains, temperature, pH, reactor load, biogas composition and volume, electricity and heat production, and the energy balance of the enterprise.