Application of Sodium Silicate from Palm Leaf Ash as Heterogeneous Catalyst in Transesterification of Palm OilRuri Rizki Syahputri Zuhri, Renita Manurung, Rondang Tambun and Hamidah HarahapE3S Web Conf., 519 (2024) 02008DOI: https://doi.org/10.1051/e3sconf/202451902008