Fundamental study of cracking gasification process for comprehensive utilization of vacuum residue

The article is devoted to investigating some fundamentals about a residue cracking gasification (RCG) process for petroleum residues which integrates the catalytic cracking of the residue and the gasification of the cracking-generated coke. Three heat carrier particles were tested to show their different activities in cracking a vacuum residue (VR), finding that the synthesized kaolin catalyst allowed the higher liquid yield and higher conversion in comparison with silica sand and a commercial FCC catalyst. The parametric influences on the product distribution for VR cracking were thus studied over the kaolin catalyst for the major parameters including reaction temperature, catalyst-to-oil ratio, steam-to-oil ratio and different VRs. The conversion over 90% and the liquid yield above 80 wt.% were achieved at 500 °C under the optimized operating conditions. The VR with higher content of residual carbon was proven to generate more coke in the cracking. The coke deposited on the catalyst was well gasified via its interaction with steam and oxygen at 800 °C, and the CO and H2 together was up to 80 vol.% in the produced syngas. The gasification-regenerated kaolin catalyst enabled the similar product distribution of VR cracking, thus justifying the technology feasibility for the tested RCG process.