This paper describes the fundamental study about utilization of co-glycerol derived from biodiesel fuel (BDF) production especially exhausted from small BDF plant which has no facility to dispose them by themselves. The method to add value to this co-glycerol is refining and production of pyrolysis oil under low temperature around 500 °C, using small solar thermal collector (STC) with type of parabola trough as its heat source. This paper especially focuses in the usage of oil products as blended fuel in BDF and the refinement and recovery of metal, which is the component of BDF production catalyst, from solid residue. Here, the blending ratio of oil to BDF was determined so that all of the oil produced was blended in the BDF produced at the same time, then oil blended with BDF consisting of 3 vol-% oil and 97 vol-% pure biodiesel (B97O3) was used. As a result, the fuel properties and engine performance of B97O3 were almost the same as B100, and the potassium derived from catalysts of BDF production was recovered as K2CO3.
