Solid waste generated from hydrocarbon cracking provides sustainable materials for making fired brick

Fluid catalytic cracking, one of the crucial processes in oil refining, converts low value heavy hydrocarbons into high value and high yield petroleum products such as light distillates and liquefied petroleum gases. This process generates waste or spent catalyst that requires disposal. Currently, about 1,000 metric tons of spent equilibrium catalyst (S-E-CAT) are generated worldwide daily. The majority of this spent material is disposed of as landfill waste, which poses environmental risk and an economic burden to the producers and the public. Our study addresses ways to reduce this waste by creating a valued byproduct. Because the chemical composition of this waste is similar to that of components used to make fired construction bricks, we evaluated formulations, and fired and tested artificial bricks utilizing this waste. The chemical and some physical characteristics of S-E-CAT materials and the water absorption properties of fired bricks produced with variable amounts of S-E-CAT materials were previously reported (Chou et al. 2009). In this study, the particle size distribution, mineralogical and thermal property characteristics, and images of the S-E-CAT materials were analyzed. Also, the compressive strength tests, freeze-thaw tests, and thermal conductivity measurements were conducted on the final fired bricks. The results indicated that final fired bricks containing 10 wt-% to 30 wt-% of S-E-CAT had compressive strength greater than 3,000 psi and met the ASTM building brick specification for a severe weathering grade. Also, the bricks containing S-E-CAT had better heat insulation properties than conventional fired bricks. The results of this study and the previous study indicate that S-E-CAT material may be a promising raw material for a new valued and sustainable construction product, and its utilization will reduce landfill waste.