Swine Lagoon Sludge as Energy Production Feedstock: Technical-economic assessment

摘要

This study aims at evaluating the potential for utilizing swine lagoon sludge as feedstock for energy production. A preliminary process model was conducted to evaluate energy balance and cost associated with sludge removal, dewatering, drying and transportation for energy recovery. Preliminary results suggest anaerobic swine lagoons are effective in reducing manure organic solids and energy content via microbial activity, i.e., 88% and 90%, respectively. Economic and energy assessment of sludge combustion indicated a sludge processing cost between $56 and $67 per animal unit (AU) per year. The combustion, drying and solid-liquid separation (dewatering) steps accounted for 75% to 80% of the processing cost. The economic value of the recovered energyheat and electricity accounts for only 24% to 28% of the processing cost. Future work will focus on refining parameters used to simulate dewatering, drying and combustion systems. In addition, economic and agronomic value of residual ashes, which represent 40% to 50% of the sludge mass, will be further evaluated to provide more insights into the overall potential of the proposed pathway as an energy treatment and utilization approach.