| 摘要 |
A process and apparatus for preheating and catalytic cracking of heavy oils are disclosed. Direct contact heat exchange of heavy feed, such as a resid, with hot product vapor from the cracking reactor provides an efficient way to preheat a heavy feed to an unusually high temperature, preferably in excess of 315 DEG C (600 DEG F). Cooling hot cracked products from an FCC or TCC reactor upstream of the main fractionator reduces thermal cracking in the transfer line. High temperature preheat reduces the viscosity of the heavy feed, improves contact of heavy feed with cracking catalyst and reduces the amount of catalyst required to effect the catalytic cracking reaction. This improves yields, permits higher cracking reactor temperatures, and reduces cat:oil coke make. |
