Processes prevent detrimental effects from As and Hg in feedstocks

The wide range of mercury and arsenic species sometimes present in raw condensates or crude oils can cause major problems such as corrosion and reduced catalyst life. This paper reports on simple, low-investment, feedstock treatment procedures which have been developed that eliminate both As and Hg impurities with very high efficiencies. During the past 20 years, refiners and petrochemical producers have experienced a serious increase in catalyst poisoning caused by mercury and arsenic. This phenomenon may be partically explained by the diversification of the feedstock supply resulting from the need to optimize the profitability of refining and petrochemical operations. The utilization of a more diverse feedstock supply containing metal impurities has led to operating problems such as corrosion of aluminum alloys in steam cracker cold boxes.