Browsing by Subject "methane"
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Item Anaerobic Co-digestion of Chicken Processing Wastewater and Crude Glycerol from Biodiesel(2011-10-21) Foucault, Lucas JoseThe main objective of this thesis was to study the anaerobic digestion (AD) of wastewater from a chicken processing facility and of crude glycerol from local biodiesel operations. The AD of these substrates was conducted in bench-scale reactors operated in the batch mode at 35?C. The secondary objective was to evaluate two sources of glycerol as co-substrates for AD to determine if different processing methods for the glycerol had an effect on CH? production. The biogas yields were higher for co-digestion than for digestion of wastewater alone, with average yields at 1 atmosphere and 0?C of 0.555 and 0.540 L (g VS added)??, respectively. Another set of results showed that the glycerol from an on-farm biodiesel operation had a CH? yield of 0.702 L (g VS added)??, and the glycerol from an industrial/commercial biodiesel operation had a CH? yield of 0.375 L (g VS added)??. Therefore, the farm glycerol likely had more carbon content than industrial glycerol. It was believed that the farm glycerol had more impurities, such as free fatty acids, biodiesel and methanol. In conclusion, anaerobic co-digestion of chicken processing wastewater and crude glycerol was successfully applied to produce biogas rich in CH?.Item Improving the Methane Production in the Co-Digestion of Microalgae and Cattle Manure(2014-04-28) Cantu, Matthew ScottThe objective of this thesis is to evaluate the effects from various treatments in the anaerobic digestion of cattle manure when mixed with microalgae. The analysis would focus on two primary subjects: the effects of different treatments on the microalgae sludge, and the balancing of the carbon-to-nitrogen ratio. The results of this experiment would give a viable estimate on the possible methane production from co-digestion of these resources. At the conclusion of the experiment, it was found that biogas production increased when algae was added to the digester. The highest methane production in the control groups, containing only manure, digestion sludge, and newsprint was 48120 L, while the highest in the mixtures containing algae and pretreated algae were 71170 L and 87715 L, respectively. Based on volatile solids, the highest production in the control groups was0.36 (L CH_(4))/(g VS), while the production rates in the algae and pretreated algae mixtures were 0.22 (L CH_(4))/(g VS) and 0.44 (L CH_(4))/(g VS), respectively. This shows that the presence of algae increases the overall methane production, but is hindered by inhibitory factors contributing to ineffectiveness in the overall digestion process. The effects of carbon balancing for the carbon-to-nitrogen ratio also showed that overall, mixtures balanced at 25:1 carbon-to-nitrogen yielded more biogas. The exception is the normal algae mixture, in which the optimal ratio was 20:1. In conclusion, the anaerobic co-digestion of cattle manure with pretreated algae, when balanced for carbon and nitrogen, can severely increase methane production rates.