Abstract by Lindsey Daems
Chemistry and Biochemistry
Efficient Conversion of Organic Waste into Biomethane
Anaerobic digestion (AD) can be used to convert biowaste into methane gas. However, the AD process alone is too inefficient to be an economically viable energy option. Our data show that pre-digestion of organic feces by the thermophile, Caldicellulosiruptor bescii (C. bescii), followed by anaerobic digestion has the potential to increase the efficiency of conversion of waste to biomethane to be a commercial source of renewable energy.
The tests used to track the progression of carbon through the process are Chemical Oxygen Demand, Total Solids, and Volatile Solids. To perform these analyses, Hach kits and ovens are used. Tedlar bags and a spectrophotometer are used to determine the composition of biogas produced. C. bescii concentration and growth are tracked during the process by gels, qPCR, and microscopic analysis.
The principle finding of our research is that C. bescii effectively converts organic feces into products that are rapidly and efficiently digested by AD to produce biogas. When compared to AD alone, pre-digestion typically yields double the amount of methane. Using pre-digestion, the composition of biogas exiting the system is about 67% methane.