The Effect of Microwave Oven Power Variations on Co-Pyrolysis Process of Oil Palm Shells and Polystyrene: Pengaruh Variasi Daya Microwave Oven Terhadap Proses Co-Pirolisis Cangkang Kelapa Sawit dan Polistirena . pssh. 2022;3:34-40. doi:10.21070/pssh.v3i.193