A potential renewable and sustainable green energy source is biomass gasification. The role of catalyst is significant in biomass gasification technology to overcome associated problems like tar reduction and to make it economically viable. Several catalysts like dolomite, alkaline metal, nickel, etc. have been incorporated which plays an essential role in higher product yield and tar reduction but holds problems like inactivity, regeneration, and cost. In this study, physio-chemical properties of coal bottom ash have been studied for its application as a catalyst in biomass steam gasification. The characterization of coal bottom ash comprises of surface morphology analysis, existing elements, pore size, and volume, as well as surface area and bulk density, were reported. The results showed that elements like Si, Fe, Al, Ca and Mg were present in coal bottom ash which have been previously used as a catalyst in biomass gasification. The pore diameter of coal bottom ash is 4 nm, the specific pore volume is 0.01474 cm3/g, specific surface area of 17.64 m2/g which lies it in mesoporous classification. Also, it is observed that CaO mineral exists in coal bottom ash support in reducing the CO2 gas while improving syngas yield. The presence of SiO2 shows that it can use as bed material while Fe2O3 improves the tar reduction in the product gas whereas CaO assists to capture CO2 in the process whereas, alumina resist sintering of metal catalyst. Coal bottom ash is economically viable due to abundance and low cost. Based on its composition (presence of Ca, Mg and other alkali metal) as analyzed .it can be used as an alkaline metal catalyst. © 2019 Elsevier Ltd. All rights reserved.