Abstract:

Mixed C4 is mainly composed of the acetylene-containing C4 from butadiene extraction plant and MTBE plant and the heavy C4 from light hydrocarbon recovery unit in refinery. This part of C4 components can be used as cracking materials after removing the olefins and alkynes by full hydrogenation. The olefins content of mixed C4 is relatively high, generally accounting for more than 65 mol％. With the operation of the plant, the olefins will be polymerized and coking in the reactor, and then block the pore channel of the catalysts over time, resulting in the decrease of catalyst activity and the increase of bed pressure difference, which will affect the product quality and the operation of the plant. Therefore, the plant has to be shut down for catalyst regeneration. The regeneration process is analyzed, and the regeneration results are evaluated, providing theoretical basis for the subsequent operation of the plant.

Key words: mixed C4, hydrogenation, regeneration process, analysis and evaluation