Carbon foam produced from fluid catalytic cracking slurry at atmospheric pressure

Pitch-based carbon foam containing pores of diameter 150–400 μm was produced from an intermediate pitch obtained from aromatic rich oil extracted from heavy oil FCC (fluid catalytic cracking) slurry by heating at atmospheric pressure. The effect of molecular weight distribution of the pitch on the formation of the foam was studied qualitatively. The variation of microscopic morphology, crystallite size, the interlayer spacing of microcrystal, and the density of the carbon foam carbonized from 800 to 1400 °C were also investigated. It was found that the wider the molecular weight distribution of the intermediate material, the worse the foam. Optical microscopy and scanning electron microscopy revealed that with increasing carbonization temperature, closed pores were opened and more pores were in twisted form. X-ray diffraction patterns indicated that the graphite microcrystal size decreased from 2.3 to 1.5 nm and their interlayer spacing increased from 0.3459 to 0.3477 nm below 800 °C. From 800 to 1400 °C, the graphite microcrystal size increased from 1.5 to 4.2 nm and the interlayer spacing decreased from 0.3477 to 0.3454 nm. The density of the carbon foams decreased form 0.52 to 0.16 g/cm3 during the carbonization.