Pyrolysis-catalytic steam reforming of waste plastics for enhanced hydrogen/syngas yield using sacrificial tire pyrolysis char catalyst

Pyrolysis-catalytic steam reforming of waste plastics to produce hydrogen-rich syngas has been investigated using tire char as a sacrificial catalyst in a two-stage pyrolysis-catalytic steam reforming reactor system. The simultaneous steam reforming of the pyrolysis volatiles and `sacrificial' steam gasification of tire char increased the overall yield of syngas and hydrogen in the gas products. Manipulating the catalyst temperature, steam input, char catalyst:plastic ratio influenced hydrogen yield. The presence of metals such as Zn, Fe, Ca and Mg in tire char, play a catalytic role in steam reforming reactions. The syngas production achieved when the catalyst temperature was 1000 degrees C and steam weight hourly space velocity was 8 g h(-)1 g(-1) (catalyst) was 135 mmol H2 g(plastic)(-1) and 92 mmol CO g(plastic)(-1). However, increasing the amount of char catalyst (4:1 char catalyst:plastic ratio) enabled hydrogen yields of 211 mmol g(plastic)(-1) and total syngas yields of 360 mmol g(plastic)(-1) to be achieved.