Liquid fuel production from waste tires and water hyacinth: A comparative study of Co-pyrolysis and Co-gasification with Fischer-Tropsch integration

• Conversion of waste tires (WT) and water hyacinths (WH) into oil was considered. • Models of pyrolysis and gasification integrated with Fischer-Tropsch were proposed. • Pyrolysis at 400°C and a WT/WH of 75/25 yields 6649.22 gal/day of liquid fuel. • Integrated process at 800°C and a WT/WH of 50/50 produced 8817.15 gal/day of fuel. • Economic comparison indicated the investment worthiness of integrated process. This study investigates the sustainable conversion of waste tires (WT) and water hyacinth (WH) into liquid fuel using two thermochemical approaches: co-pyrolysis (direct method) and co-gasification integrated with Fischer-Tropsch (FT) process (indirect method). Aspen Plus software was employed to determine optimal operating conditions for maximizing fuel yield. The direct method achieved 6,649.22 gallons of fuel per day at 400°C with a WT/WH ratio of 75/25. In comparison, the indirect method, operating at 800°C with a WT/WH ratio of 50/50, produced 115.92 kmol/h of syngas, which was subsequently converted into 8,817.15 gallons of liquid fuel per day via the FT process. An economic analysis revealed that the indirect method offered higher fuel yields and better cost-effectiveness, with a capital investment approximately 5 million U.S. dollars lower than the direct method. These findings highlight the potential of integrating waste-derived feedstocks for efficient and sustainable liquid fuel production.