Circular fuel production through steam reforming of waxy crude sludge: Enhancing syngas production using transition bimetallic catalyst

Abstract

Waxy crude sludge (WCS) is an ignitable and hazardous semi-solid mixture containing petroleum, water, and heavy metals. Due to its high hydrocarbon content, WCS is a promising feedstock for syngas production. The carbon and hydrogen conversions were found to depend on temperature, primarily due to endothermic reactions. Ni and Cu metals were successfully doped onto dolomite to synthesize mono-metallic and bi-metallic catalysts to enhance the steam reforming. Notably, bimetallic Ni-Cu/dolomite catalysts exhibited high H2 and CO conversions. The 5 %Ni-5 %Cu/dolomite catalyst achieved the highest conversion yield, with total CO and H2 conversions of 21.15 % and 28.93 %, respectively, resulting in a H2 to CO molar ratio of 1.36 and a lower heating value (LHV) of 5.35 MJ/m3. These findings indicate that the surface-active site of dolomite-supported Ni-Cu catalysts exhibit enhanced activity and reduced carbon deposition. The study also demonstrated that using bimetallic catalysts with inexpensive mineral supports like dolomite is a viable solution for generating syngas from waxy sludges encountered during petroleum drilling operations. Additionally, this process aligns with the principles of the circular economy, facilitating energy generation and efficient hydrogen production.