Waste Cooking Oil into Biodiesel Transformation and its Economical Potency through Circular Economic Model in Semarang Barat Area IndonesiaArie Wicaksono, Widayat and Singgih SaptadiE3S Web Conf., 125 (2019) 14010DOI: https://doi.org/10.1051/e3sconf/201912514010