Gasification of dry refinery sludge has gained a lot of interest of late. Fly ash and sludge ash are waste by product of gasification process. Using these ashes as catalyst material can reduce the waste disposal to landfill sites. This study has shown that both fly ash and sludge ash can be used as a catalyst in gasification as it is rich in catalytic material like silica, alumina, ferric oxide, calcium oxide and a host of other catalytic materials. These ashes catalytic material shows improved syngas quality when blended with dry refinery sludge (DRS) in updraft gasification process thereby enhances its economic viability. Furthermore, mixing of these catalysts with sludge fuel cause reduction of the agglomeration of metal oxides inside an up draft gasifier. The presence of fly and sludge ash catalyst are found to convert stable tar into gaseous products, thus enhance the hydrogen production by moving water-gas shift reaction to forward direction. Experiments were performed to determine the catalytic effects of fly and sludge ash using various percentages ranging from 0, 10, 15 and 20 and with equivalent ratio (ER) of 0.195 and 0.24. The study was centered on the product gas, heating value, combustible gases vol, and cold gas and carbon conversion efficiencies. It was found that both fly and sludge ash has enhanced catalytic properties. An ER of 0.195 is best suited for the gasification of dry refinery sludge. Increase in the catalyst addition improves gas quality, increases high heating value (HHV) and cold gas efficiency. © 2018 Institution of Engineering and Technology. All rights reserved.