Environmental Impact and Energy Production: Evaluation of Biochar Application on Taiwanese Set-aside Land

This paper examines the possibilities for domestic bioenergy production in Taiwan utilizing set-aside land. Three bioenergy alternatives are examined-pyrolysis-based electricity, conventional bioelectricity and bioethanol. We examine the comparative economics and choice among these alternatives under current Taiwanese agricultural system policies and also under altered energy and greenhouse gas / carbon prices. Biochar, produced from pyrolysis, is also examined in terms of whether it is best used as an energy source and/or a soil amendment. The studies concern the total economic, environmental, agricultural and energy security effects across the bioenergy production alternatives. The study employs a Taiwanese Agricultural Sector Model (TASM) to simulate the effects of the alternatives in the face of energy and greenhouse gases prices. The TASM is based on price endogenous mathematical programming and includes more than 85 percent of Taiwan’s total agricultural product value. The current version of TASM accommodates more than 110 commodities in 15 subregions aggregated into 4 major production and processing regions. To do this simulation the TASM model was extended to include additional bioenergy production possibilities and GHG accounting. Results show that bioethanol production is chosen under current conditions but that this is replaced by pyrolysis-based electricity when the GHG price is high. We also find that when biochar is hauled back to the rice fields, GHG emission reduction is higher than when biochar is burned for electricity; however, national electricity production is consequently higher when biochar is burned. Thus the choice among these alternatives depends on energy prices versus GHG prices. The results also indicate that pyrolysis-based electricity can provide up to 1.84% of Taiwan’s annual electricity demand and offset up to 0.53% of Taiwan’s annual GHG emissions.