The addition of absorber can lead to increase the reaction temperature in the microwave pyrolysis process. Three different sources for microwave absorbers were used to identify the effect of microwave absorber on the product yield from microwave pyrolysis of oily sludge. These absorbers are namely, coconut activated carbon (CAC), palm kernel shell activated carbon (PKSAC) and petroleum coke. The microwave absorbers were added to elevate the temperature of pyrolysis reaction in a nitrogen atmosphere using a modified microwave household reactor. The process included identifying the effect of microwave absorber concentration, and initial moisture content at an optimum sweep gas flow rate on the product yield. The results demonstrated that the addition of CAC, PKSAC and petroleum coke improved the heating rate by shortening the drying process. The results showed that the addition CAC during microwave pyrolysis of oily sludge resulted in the higher gas product distribution compared to other types of absorbers. The results revealed that the addition of 10% of the CAC can pyrolyze oily sludge at a nitrogen gas flow rate of 200 mL/min. At this condition, ~65 wt% of gas was produced for all moisture content of oily sludge samples (4%, 40% and 75%). As well as, this treatment method shortened drying time of oily sludge to 30 minutes. The results showed that higher produced gases of H2 (15%) and CO (13.3%) giving lower heating value (LHV) at 5.57 MJ/m3 were achieved using 10% of CAC in microwave pyrolysis of oily.
