Effect of agitation time on nutrient distribution in full-scale CSTR biogas digesters

摘要

Highlights?Mixing is a major driver of electric efficiency in biogas plants.?A reduction in mixing time did not result in major uneven nutrient distribution.?Electricity demand could be reduced of up to 81%.?Overall operational safety should be taken into account when setting up mixing devices and operation mode.AbstractThe aim of this work was to study the impact of reduced mixing time in a full-scale CSTR biogas reactor from 10 to 5 and to 2min in half an hour on the distribution of DM, acetic acid and FOS/TAC as a measure to cut electricity consumption. The parameters in the digestate were unevenly distributed with the highest concentration measured at the point of feeding. By reducing mixing time, the FOS/TAC value increases by 16.6%. A reduced mixing time of 2min lead to an accumulation of 15% biogas in the digestate.]]>