An economic and environmental evaluation of Taiwan's manure to energy applications

Cost and benefit information is essential for Taiwan to determine economically feasible manure applications. This study adopts techno-economic analysis and life cycle assessment to evaluate manure's energy potential under six composting, pyrolysis, and anaerobic digestion possibilities. Biogas fertilizer and biochar use in agriculture is also examined. The results show that the cost-effective manure applications depend on the recycling method, input of raw materials, and economic scale. Pyrolysis yields up to $175.74 per ton of feedstock, but composting is subject to a loss when emission prices skyrocket. Hog and cattle manure applications may break even in costs, but chicken manure could incur a loss of $25.28 under mesophilic and $19.16 under thermophilic fermentation. Manure distribution would also substantially affect large-scale biopower development due to high transportation and operation costs, and the development cost could dramatically vary by region. The 2023 US dollar is used as the basis.