Energy Potential and Bioethanol Production Potential from Collectable Major Crop Residue in China

Crop residue is an important and abundant biomass resource. Accurate estimation of its bioenergy potential is important for promoting renewable energy use and sustainable environmental development. Based on the county-level crop yield data and crop residue coefficients by province, this study estimates China’s collectible residue production, bioenergy potential, and bioethanol production potential of wheat, rice, and maize at the county level in 2015. The results show that after considering the limitations of residue harvesting coefficients and transportation costs, the total collectible crop residue of wheat, rice, and maize in China in 2015 was 501 million tons. The total bioenergy potential reached 244 million tons of equivalent standard coal, accounting for about 5.68% of China’s total energy consumption in 2015. The theoretical production of bioethanol was 81 million tons. In addition, biomass energy potentials in China exhibit strong spatial heterogeneity. It presents a decreasing trend from the east to the west, and the hotspots are concentrated in the two major grain-producing regions, the Huang-Huai-Hai plain and the Northeast Plain.In summary, significant latent biomass energy potential exists within the residues of Chinese wheat, rice, and maize. Further advancement in the utilization of maize residues as an energy source holds promise for alleviating China's increasingly severe energy crisis, while concurrently yielding substantial environmental benefits.