Plug-flow anaerobic digestion with multi-position sensors: The value of gradient measurement for process monitoring

In the present study, a tailor-made plug-flow reactor with 3D-printed parts and multi-position monitoring of pH-value, conductivity ORP at inlet, center outlet part is introduced applied in anaerobic digestion order to investigate whether i) formation gradients can be detected, ii) ideal single or multiple spots for location sensors during an acidification process identified, iii) spatial gradient acquisition allows indirect performance measures, e.g. accumulation short-chain carboxylic acids. During full dark fermentation maize grass silage, liquid phase revealed that local inlet center, pH-value are relevant gain information performance, while between early detection disturbances.