Indra Mamad Gandidi, Asep Bayu Dani Nandiyanto, Qori Zulia Rahma, Sukarni Sukarni, Dwi Aries Himawanto, Susanto, Arinal Hamni, Daddy Budiman
This study presents an innovative integrated two-step co-pyrolysis approach for heterogeneous multi-component municipal solid waste (MC-MSW) using natural dolomite as a dual-function CaO–MgO catalyst in an integrated two-step co-pyrolysis system (ITSC). The effects of temperature (450–550 °C), residence time (120–180 min), and feedstock-to-catalyst ratio (1:2–1:2.5) were optimized through the Box–Behnken design and desirability function approach. The MC-MSW consisted of 32% biomass, 54% mixed plastics, 9% paper, 3% textiles, and 2% rubber. Natural dolomite was selected for its abundance, low cost, and balanced acid‒base catalytic activity, enhancing cracking and deoxygenation. Under optimal conditions (500 °C, 158 min, 1:2.5 ratio), the process yielded 34.2 wt% liquid fuel with a higher heating value (HHV) of 41.8 MJ/kg, dominated by C5–C12 hydrocarbons (78.3%) and aromatics (66.5%). In contrast, the non-catalytic run produced only 25.6 wt% liquid with 36.9 MJ/kg HHV and a higher oxygenated volatile fraction. These findings demonstrate that natural dolomite significantly enhances conversion efficiency and product quality while supporting circular carbon valorization through reduced emissions and improved energy recovery from heterogeneous urban waste streams. The process supports sustainable development goals (SDGs 7, 11, and 12) by enabling clean energy generation, sustainable urban waste valorization, and circular economy integration through reduced emissions and efficient energy recovery from heterogeneous municipal waste streams. © 2026 The Author(s).
Energy and Bioprocess Technology Laboratory, Department of Chemical Engineering, Faculty of Technology and Industrial Education, Universitas Pendidikan Indonesia, Bandung, 40154, Indonesia; Energy Research on Green Material, Innovation & Application (ENERGIA), Universitas Pendidikan Indonesia, Bandung, 40154, Indonesia; Department of Mechanical Engineering Education, Faculty of Technology and Industrial Education, Universitas Pendidikan Indonesia, Bandung, 40154, Indonesia; Center for Renewable Fuels Research (CRFR), Department of Mechanical and Industrial Engineering, Universitas Negeri Malang, Malang, 65145, Indonesia; Center of Advanced Materials for Renewable Energy (CAMRY), Universitas Negeri Malang, Malang, 65145, Indonesia; Department of Mechanical Engineering, Universitas Sebelas Maret, Surakarta, 57126, Indonesia; Vocational Program of Engineering, Politeknik Maritim Negeri Indonesia, Kabupaten Semarang, 50552, Indonesia; Department of Mechanical Engineering, Universitas Lampung, Bandarlampung, 35145, Indonesia; Department of Mechanical Engineering, Politeknik Negeri Padang, Padang, 25164, Indonesia
