Abstract: The invention relates to a method for separating meta-xylene from C8 aromatic fractions, using a zeolitic adsorbent based on sodium-exchanged or sodium-and-lithium-exchanged agglomerated crystals of zeolite Y, with a large external surface area.

Abstract: A fluidized bed apparatus has a rotary rotor 4 arranged at the bottom center thereof, a disintegrator mechanism 5 arranged above the rotary rotor 4, and a cylindrical draft tube 6 installed above the disintegrator mechanism 5. A fluidizing gas jetted from a gas dispersion plate 3 causes powder particles P in a processing container 1 to form a fluidized bed in which they circulate so as to ascend through the gap between the outer periphery of the rotary rotor 4 and the bottom inner wall of the processing container 1, the space between the disintegrator mechanism 5 and the inner wall of the processing container 1, and the space between the outer periphery of the draft tube 6 and the inner wall of the processing container 1, and descend through the inner portion of the draft tube 6.

Abstract: A bed height of a fluidized bed is detected which influences reaction of a fluidized-bed equipment. In the fluidized-bed equipment in which a fluidized particle is put into the vessel, physical properties at a plurality of points within the vessel are measured in a height direction thereof. An interior of the vessel is divided into upper and lower two regions. Physical property distribution curves of the respective regions are found, to find an intersection between the two curves as a bed height. Thus, it is possible to find the bed height of the fluidized bed which influences the reaction of the fluidized-bed equipment. An operating quantity which influences the reaction can be adjusted or regulated accurately.