PAFC fed by biogas produced by the anaerobic fermentation of the waste waters of a beet-sugar refinery

Beet-washing waters of a beet-sugar refinery carry a high COD (Chemical Oxygen Demand), and their conditioning to meet legal constraints before disposal considerably contributes to the operation costs of the refinery. Their fermentation in an anaerobic digestor could instead produce readily disposable non-polluting waters, fertilizers and biogas, useful to feed a phosphoric acid fuel cell (PAFC) heat and power generator system. A real refinery case is considered in this work, where the electrical characteristics V = V(I) of a laboratory PAFC stack, fueled with a dry simulated reforming gas (having the same H{sub 2} and CO{sub 2} content as the biogas obtainable by the above said anaerobic digestion), are determined. The encouraging results show that a possible market niche for fuel cells, in the food-industry waste partial recovery and residual disposal, deserves attention.