Simulation studies on the co-production of syngas and activated carbon from waste tyre gasification using different reactor configurations

Gasification is one of the most efficient thermo-chemical conversion processes for transforming waste tyres into syngas and high-valued solid carbon products such as activated carbon (AC). This study evaluated the co-production of syngas and AC in three reactor configurations: fluidized bed, fixed bed, and rotary kiln at the systems level. A single-stage steam gasification and char activation process was simulated using Aspen Plus V10 software. The effects of gasification parameters such as equivalence ratio (ER) and steam-to-fuel ratio (SFR) were investigated and compared. The best conditions for the co-production of syngas and AC in the reactors were evaluated and compared. Brunauer-Emmett-Teller (BET) computational analysis was used to predict the surface area of the AC. The fluidized bed gasifier has the potential to produce syngas with a low heating value (LHV) of 6.67 MJ/Nm3, cold gas efficiency (CGE) of 82.4%LHV, AC with BET surface area of 698.63 m2/g and a carbon conversion ratio (CCR) of 92.5%, the fixed bed gasifier has a syngas LHV of 6.25 MJ/Nm3, CGE of 85.9%LHV, AC with BET surface area of 432.51 m2/g and CCR of 97.3% and the rotary kiln gasifier has a syngas LHV of 5.96 MJ/Nm3, CGE of 74%LHV, AC with BET surface area of 661.73 m2/g and CCR of 93%.