Development of velocity sensor to optimize the energy yield in a biogas plant

Abstract

The number of biogas plants has increased worldwide making the energy from Biomass one of the main renewableenergy resources. Along with the increase of number of biogas plants, the prices of the substrates have beenincreased. Therefore, the optimization of the energy efficiencies in biogas plants has become a crucial subject. Anoption to improve the efficiency of the biogas plants is by optimizing their stirring system, where up to 51% from theinternal energy consumption in biogas plants might be caused by the stirrers. The evaluation of the current mixingperformance is done by performing velocity testing with a reliable technology - the bending beam-. The mainadvantages of this sensor in advance to the simple technology are the cost reliability, accuracy, resistivity against fouland ability to be installed inside the fermenters. The results showed the efficient use of the sensor and an inaccuracyof the range (4-6) %. The effect of the Total Solids content (TS) of the digestate on the mixing inside the fermenter wasdetermined; at higher TS values, the flow of the substrates becomes more uniform than at lower TS values.