An environmental and economic assessment from bioenergy production and biochar application
Aiyun Nie, Shan-Shan Kung, Hailing Li, Liguo Zhang, Xiaogang He, Chih-Chun Kung
Abstract
Pyrolysis has been considered an effective bioenergy technology to produce renewable energy; however, the extent to which it mitigates climate change is greatly influenced by the usage of its by-product, biochar. Bioenergy development relies on the stable supply of agricultural commodities; however, climate-induced impacts on crop yields that potentially influence the stability of biomass supply must be investigated. The current study analyzed Taiwan’s bioenergy potential and the associated economic and environmental consequences. A two-stage stochastic programming with a recourse model was employed to explore the biofuel and biopower production under various climate impact possibilities. Furthermore, emission offsets, such as CO2 reduction from bioenergy production and N2O reduction from biochar application were elucidated, along with changes in cropping patterns. The results indicated that: (1) with onsite biochar application, up to 8 82 000 metric tons of CO2-equivalent emissions can be offset from the reduction of fertilizer use; (2) ethanol is less competitive, with more than 99% of bioenergy is derived from pyrolysis-based biopower; (3) net offset potential substantially decreases when N2O emissions from cropping land are considered; and (4) biochar can contribute up to 42.43–51.02% of the total emission sequestration. The net impact of promotion policies on social welfare depends on the size of gains obtained by producers and losses experienced by consumers, and researchers need to incorporate the heterogeneous properties of these policies to determine the country-specific effects of bioenergy development on social welfare.