| abstract |
A collapsed composition is described which is substantially composed of microcrystallites collectively of formula (I), where M2+ is a divalent metal, M3+ is a trivalent metal, and T is vanadium, tungsten, or molybdenum. The microcrystallites are so small as to be undetectable through conventional x-ray diffraction techniques, yet high resolution electron microscopy reveals that a substantial portion of the microcrystallites are composed of a solid solution having aluminum oxide molecularly dispersed in a divalent metal monoxide crystal structure. Another portion of the microcrystallites are constituted by a spinel phase. The collapsed composition is suitable as a sulfur oxide absorbent, having comparatively high capacity and comparatively fast absorption and desorption rates. The collapsed composition may be produced by heat treating a layered mixed hydroxide clay having interlayer anions in monometalate form. A sulfur oxide separation process is also presented. The process can be operated cyclicly and integrated with any of several well-known fluidized bed catalytic cracking processes. |