Single‐stage Treatment in Selective Hydrogenation of Acetylene over CDS Type of Pd‐Ag/Al₂O₃ Catalyst

Abstract

The (computer designed shape) CDS type of Pd‐Ag/Al2O3 catalyst in single‐stage reactor provides superior catalytic activity and selectivity of ethylene in comparison with those of existed two‐stage reactors packed with G‐58B catalyst under industrial operating conditions. In this research, the contents of palladium and silver of catalysts were analyzed by inductive coupling plasma (ICP). The X‐ray photoelectron spectroscopy (XPS) showed that Pd‐Ag alloy has been formed. Higher yield of ethylene may be interpreted by both geometric and electronic effect induced from silver metal. By means of Pyrolysis/GC/MS analysis of used catalysts, the components of carbonaceous deposits were found to be n‐alkenes, including n‐C8 ∼ n‐C16 or n‐C18, which may result from oligomerization of acetylene.

Dynamic control of a selective hydrogenation process with undesired MAPD impurities in the C3-cut streams

“…For gas phase hydrogenation, which was frequently used in the early naphtha cracker processes, the formed green oils quickly cover the interior and exterior surface of the catalyst and cause rapid catalyst deactivation [3][4][5]. As a routine practice in the industry, the catalyst is periodically regenerated to recover the activity.…”

Mesoporous silica gel doped with dysprosium and modified with copper: A selective catalyst for the hydrogenation of 1‐hexyne/1‐hexene mixture

“…[20][21][22][23][24] Catalysts for selective hydrogenation are often modified with various promoters to increase their activity, most often with transition metals such as copper, silver, and gold. [25][26][27][28][29] The addition of copper as a modifier increases the selectivity for alkenes in the hydrogenation of acetylenic and diene hydrocarbons. 30 The chemistry of alkynes has been well studied on transition metals used as catalysts.…”