Assessment of rapeseed-based biodiesel potential on winter fallowing fields in the middle and lower reaches of Changjiang River, China

摘要

The development of bio-energy is one of the keys to solve global energy crisis and climate changes. With the characteristics of wide adaptive range and similar chemical composition as that of diesel, rapeseed has been regarded as an important raw material for the development of biodiesel in Europe and other regions. The middle and lower reaches of Changjiang River is the traditional main region of rape in China. The growing area in the 7 provinces reached 4 million ha annually. Due to the progress of urbanization and related policies, large quantities of fields in these areas are left idle in winter. The use of these rich land resources for the growing of rape in biodiesel development can contribute to alleviating the energy crisis without affecting the national food security. In light of this, the paper put forward a method for comprehensive assessment of rapeseed-based biodiesel potential in this region. Firstly, the areas of winter fallowing fields were extracted by combining use of remote sensing imagery and in situ phenology data. The result indicated that the area of winter fallowing fields in the middle and lower reaches of the Changjiang River in 2010 was 5.47×10~4km~2, which represented 35.73% of the total cultivated fields in the research area. The yield of rape of winter fallowing fields was estimated to be 1.07×10~7 ton, which was equivalent to 2.56×10~6 ton of biodiesel production. If these resources are fully utilized, the strategic goal of the annual production of 2 million t of biodiesel in 2020 as specified in National Medium and Long-term Development Plan for Renewable Energy can be reached.