INLINE PROCESS MONITORING & CONTROL FOR AD PLANTS
For efficient biogas production sludge bacteria require a pH in the range of about 6.5 to 8. A stabilization of the pH in this range is mainly (> 85 %) achieved by the large amounts of bicarbonate (= buffer substance), which are released during the anaerobic degradation. Disturbances of the biological degradation regularly increase the level of volatile fatty acids. Because acids consume bicarbonate, this leads to a decrease in the level of bicarbonate. However, by the buffering action of the bicarbonate, the pH value is hardly reduced initially.
Only if the disturbance persists over time and the stock of bicarbonate is largely exhausted, there is a rapid drop in the pH. This leads to a reduced biogas production or, in extreme cases, to a total loss of the biogas production.
ADVANTAGES OF THE MEASUREMENT TECHNOLOGY
» By a fully automated monitoring of the bicarbonate content, process disturbances can be recognized much earlier than by a simple monitoring of the pH.
» The high data density of the automatic measurement enables a close temporal association with changing operating conditions. The often difficult determination of causes of process disturbances is much easier this way.
» In total bicarbonate measurement technology increases the availability of biogas plants and thus their economic success.