Crop residue utilizations and potential for bioethanol production in China

Abstract Crop residue is an abundant and lucrative biomass resource in China, which is expected to decrease its reliance on coal and petroleum through the use of crop residue. This study was conducted with the data of crop production released by the National Bureau of Statistics of China and 1417 valid face-to-face questionnaires on residue utilizations. It was found that the crop residue increased from 725.47 Mt in 2007 to 897.06 Mt in 2016 at the annual rate of 2.63%. It amounted for 897.06 Mt including 781.32 Mt field residue and 115.74 Mt and process residue, respectively in 2016. Field residue retained in field exhibited the highest ratio (35.19%), for bioenergy use was less than 1%. A total amount of available field residue (AFR) for bioethanol was 254.57 Mt in 2016. Maize provided the greatest quantity of AFR (95.00 Mt), followed by rice (78.90 Mt) and wheat (18.89 Mt), sum of three accounted for 76% AFR in China. The largest AFR was found in Heilongjiang (39.79 Mt), followed by Henan (31.03 Mt) and Jilin (22.51 Mt). The density of AFR exhibited high in NEC and CSC and southeast provinces of SWC. The bioethanol potential was 124.3 Mt in 2016, with maize, rice and wheat residues representing 77.8% of the total. The four top-ranked provinces of bioethanol potential were Heilongjiang, Henan, Jilin, and Sichuan. It was suggested that financial and taxation support are necessary to promote cellulosic bioethanol research and industrial use in its early stage.