Novel system for demand-oriented biogas production from sugar beet silage effluent

Abstract

In recent years, the concept of flexible electricity production from renewable energy sources has gained popularity in the field of renewable energy supply. This study investigated a new system for flexible biogas production in praxis scale biogas plants involving new sugar beet storage processes aiming on the use of produced sugar beet silage effluent. Both processes showed successful ensiling with moderate losses compared to conventional sugar beet storage processes. A clear advantage was found in the use of washed and chopped sugar beet for silage effluent production. Thanks to the high COD-content and high digestibility, the produced silage effluent was applicable for point feeding. The system’s response, observed as an increase in gas production, was noticed within a few minutes. The time required to obtain the maximum gas production rate was in the range of 1:42±0:47 h. The obtained average methane yield during point feeding was 0.38±0.08 m³ kg^‑1 oDM. No VFA accumulation or biological process disturbances of the full-scale biogas plant took place while point feeding.