Comprehensive assessment of sustainable potential of agricultural residues for bioenergy based on geographical information system: a case study of China

This study proposes an approach for estimating the sustainable potential of agricultural residue biomass, with the novel characteristic of combining regional annual crop yields, topographic and legislative restrictions, as well as local soil organic matter and soil erosion considerations in the sustainable potential assessment. The proposed approach is applied in the case of China. To ensure accuracy and reliability of the evaluation, the theoretical potential was first calculated based on the residue-to-product ratio (RPR) in China at a regional level. Based on the theoretical potential, a geographic information system (GIS) was then employed to determine the technical potential and sustainable potential of agricultural residues in China. The theoretical, technical and sustainable potential of agricultural residues were found to be equal to 1001.47, 565.82 and 143.20 Mt per year, respectively. Up to 20% of agricultural residues are technically collectable but not currently utilized as resources; if appropriately utilized as an energy source, these residues could generate up to 108 TWh of bio-based power per year. However, for sustainability purposes, the maximum energy potential is limited to 27.8 TWh/year. It was also found that among China's 31 provincial regions, Heilongjiang holds the greatest potential for the establishment of an agricultural residue-based economy by virtue of its resource availability.