Management of Silicon Contamination on Pygas Hydrogenation Catalyst for a Steam Cracker

An increasing number of petrochemical producers are actively exploring the transition to a circular economy as a means to enhance sustainability in plastics production. Within this shift, the incorporation of new feedstocks into steam crackers has raised challenges due to high contamination levels. Notably, pyrolysis gasoline plays a pivotal role in managing the effluent from liquid furnaces, concentrating many of the contaminants found in the steam cracker feedstock. Silicon contamination is one that has emerged as a significant concern due to its detrimental impact on the performance of Pyrolysis Gasoline (PyGas) hydrogenation catalysts. This article investigates the mechanisms of Silicon contamination, and explores its effects on the catalytic activity of PyGas hydrogenation catalyst, first and second stage. The sources of Silicon contamination, including circular feedstock’s, are reviewed to understand the pathways through which Silicon impurities enter the Steam Cracker process. The purpose of the PyGas first stage hydrogenation catalyst is to eliminate the highly reactive species such as diolefins, styrenics and indenics. The purpose of the PyGas second stage hydrogenation catalyst is to saturate the olefins and remove the sulfur present in the PyGas. With this knowledge, this paper will explore strategies for mitigating Silicon contamination, including feedstock purification, catalyst modification, and process optimization. The insights provided in this paper will aid in developing effective solutions to address Silicon-related contamination, leading to improved performance and operational reliability.