Abstract: Ethylene plant, FCC unit and MTO plant produce a considerable amount of C4-C8 olefin fractions as byproducts. Utilizing these low value-added byproducts to produce ethylene/propylene through olefin catalytic cracking can increase the economic benefits of enterprises. The raw material C4-C8 olefin fractions generally contain impurities such as oxides, sulfur and H²O. Not many impurities are produced during catalytic cracking. In order to obtain polymer grade ethylene and propylene products, an adsorption system needs to be set up to remove the impurities entrained into the system by raw material. This article introduces the regeneration process of the adsorption system and the design calculation of related orifices.

Key words: olefin cracking, refining, adsorption, polymer grade ethylene and propylene, dehydration, orifice calculation