Performance assessment and enhancement of anaerobic digestion of organic wastes from a snacks production facility

Erdost, Begüm Gür
A snacks company; that manufactures potato, corn and corn grain chips constructed an anaerobic co-digestion facility (ACF) having a total volume of 4200 m3. The process involved anaerobic co-digestion of anaerobic sludge from its wastewater treatment plant (WWTP), along with organic waste generated in the plant. The anaerobic co-digestion process had two products; 60 % methane containing biogas, and digestate with improved fertilizer characteristics compared to raw organic waste. Produced biogas was being utilized in a co-generation plant, where electricity and heat was produced. The main objective of this study was to enhance biogas production of the ACF. Two routes were followed for this purpose; first being the investigation of OLR effects in an experimental set-up; and second being the assessment of ACF’s biogas production performance through observation of biogas production rate, and OLR. Results obtained from the experiments conducted were used to improve ACF’s OLR regime. Experimenting with Organic Loading Rates of 3.3; 5.3 and 6.4 kg VS/m3.d; biogas production rates of 114 L/d; 207 L/d and 246 L/d have been obtained respectively. Related biogas yield values have been found out as 0.396; 0.431 and 0.200 L/g VS added. Based on the results of the experimental study, two conclusions were drawn: OLR of 5.3 kg VS/m3.d resulted in the highest biogas production rate, and an OLR of 6.4 kg VS/m3.d inhibited the mixed anaerobic cultures and thus biogas production capacity. Regarding the studies realized in real size ACF; adjusting the loading regime and increasing the average OLR from 1.8 kg VS / m3.d to 3 kg VS / m3.d resulted an increase of 50% in the biogas production rate; that would result in an annual greenhouse gas saving of 1,534,250 m3 .


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Citation Formats
B. G. Erdost, “Performance assessment and enhancement of anaerobic digestion of organic wastes from a snacks production facility,” M.S. - Master of Science, Middle East Technical University, 2010.