PETR 24 |
| The basic and fundamental principles involved in the FCC SOX reduction technology have been presented, including discussion of some of the principal players involved. An evaluation of thermodynamics has indicated that the system involving magnesium oxide (in the form of magnesium oxide / aluminum oxide solid solution) is the only commercially viable FCC SOX control method . A subtlety that eluded most researchers is the fact that most sulfates , formed in the regenerator , reduce to sulfides in the reactor rather than to the desirable and necessary oxide. Kinetics in the reactor and regenerator are somewhat difficult to determine. Fortunately, a circulating fluidized bed reactor (LAB unit) was available that simulates commercially observed SOX reduction activity , as well as FCC process performance , quite accurately. Developing laboratory/pilot plant techniques that simulate sorption agent deactivation in a commercial FCC unit was quite difficult. Subsequent experimentation led to a deactivation technique with a fixed fluidized bed (FFB) - that was shown to mimic commercial deactivation - operated at 15 psig. It was shown that the combination LAB/FFB permitted accurate evaluation and simulation of sorption agent activity/stability and permitted to precisely project commercial FCC sorption agent performance. The accuracy and reliability of the LAB/FFB pilot plant was subsequently confirmed in seven commercial trials. Using the combination of LAB/FFB , it was shown that Ce on MgAl2O4 was a viable FCC SOX sorption agent and confirmed subsequently in three commercial trials. Based on knowledge gained while examining the thermodynamics of FCC SOX reduction and further experimentation led to the discovery that MgO rich solid solutions of MgO · Al2O3 with Ce were preferred. Subsequent R&D resulted in the discovery that a loss of oxidation function is the principal cause for sorption agent deactivation.
|
|
7th International Symposium on Advances in Fluid Cracking Catalysts (FCCs)
1:30 PM-5:00 PM, Sunday, 10 September 2006 Palace -- Telegraph Hill, Oral
Division of Petroleum Chemistry |