Mark Brayden, Dow Chemical Company, 21255 La. Hwy. 1, P.O. Box 400 Building 2504, Plaquemine, LA 70765, Dwight Hines, BASF Corporation, P.O. Box 2506, Highway 366, Gate 99, Port Arthur, TX 77643, James Graham, Olefins Technology Department - Feedstocks/Yields/Optimization, ExxonMobil Chemical Co., 4500 Bayway Drive, BTEC E 2053, Baytown, TX 77522, Art Baumgartner, Shell Chemical Co., P.O. Box 1380, Houston, TX 77251, and Thomas Pickett, Shaw Stone & Webster Inc., 1430 Enclave Parkway, Houston, TX 77077-2023.
Trace contaminants in feedstocks to ethylene production units cause various processing issues and impact final product purity. This paper explores the top 5 feedstock contaminants that were identified in the 2004 survey paper, "Feedstock Contaminants in Ethylene Plants -- An Update". According to the survey, the top five contaminants, based on number of respondents reporting issues with it, are sulfur, methanol, sodium, chlorides, and carbon dioxide. Each impurity will be discussed in some detail as to the source of the contaminant, how it partitions in the plant, any reactions that it may undergo, how it is removed, analytical methods, and its impact on final product specifications.