Waste Oil and Fat Feedstocks for Biodiesel Production

摘要

Biodiesel is an alternative for fossil diesel that is produced by transesterification of oils and fats with alcohol. For the sustainable development of this environmental-friendly fuel, feedstock availability is one of the most important issues. Various oils and fats commonly available in China are investigated to clarify their potential as feedstock of biodiesel, in terms of oil yield, characteristics and fatty acid composition. It was found that high potential in feedstock availability can be expected for oils from palm oil. Calculation is made for the amount of waste oils and fats discarded in China. 10 waste oil/fat samples were collected and subjected to the analyses such as acid value, water content, peroxide value, iodine value and fatty acid composition for evaluating as a feedstock of biodiesel. In general, used cooking oil from food service industry and/ or households may consist of rapeseed oil and soybean oil according to Chinese dietary habit. China produced 13.74 Mt of waste oil in 2010, including 6.58 Mt of gutter oil, 1.55 Mt of acid oil, and 5.61 Mt of rice bran oil. If all these waste oils and fats were utilized in biodiesel production, nearly 10.84 Mt of biodiesel can be prepared. On the other hand, approximately 146.34 Mt of fossil diesel fuel was on sale annually in China. It was therefore suggested that approximately 7.4% of annual fossil diesel fuel consumption can be replaced by biodiesel derived from wastes.