Potential Analysis of Common Crop Residues for Bioenergy Sources in Taiwan

Abstract

To evaluate the bioenergy potentials of Taiwan for policy making, the annual potentials of common crop residues have been estimated to be about 1.7 × 10⁶ metric tons (dry matter) using the national crop production data and the crop residue factors. Based on the estimated amount, a preliminary benefit analysis showed that the total energy potential of 2.5 × 10⁴ TJ/y could be gained in Taiwan. It is equivalent to the reduction in net greenhouse gases emissions of around 2.3 × 10³ and 1.8 × 10³ Gg/y as a result from the substitutions of coal and oil, respectively. In addition, the potentials of the common crop residues for biogas (methane) generation and bioethanol production were estimated to be around 3.0 × 10² Gg/y and 1.7 × 10⁵ m³/y, respectively.

Keywords:

• bioenergy
• bioethanol potential
• cereal crop
• lignocellulosic residue
• methane potential

Notes

^aPotential generation of common crop residues was estimated by using the residue/crop product ratios (IPCC, 1997).

^aThe three-year (2006–2009) average of crop residue (Table 1).

^bAdopted by IPCC (1997).

^cAssuming the crop residues to be completely oxidized (100% oxidized).

^dAssuming the higher heating value of fuel carbon to be 33.8 MJ/kg (Tchobanoglous et al., 1993).

^aThe calculation of GHGs emissions was on a basis of annual energy output of 24,530 TJ/y from common crop residues.

^bDEF denotes default emission factors (IPCC, 2006).

^cThe value in the parenthesis means that the emission of CO₂ from crop residues should be “0” because the biomass energy is close to “carbon neutral.”