(121a) Applying Filtration & Coalescence Technologies for the Removal of Contaminants in the Ethylene Process - Contaminants & Impurities in Ethylene Plants Subcommittee Tutorial

The presence of contaminants plays a critical role in maintaining equipment reliability and process stability in the ethylene production. The critical areas where contaminant-free process fluid is essential include cracking furnace, low NOx burner, molecular sieve dryer, caustic scrubbing tower, process water steam stripper, and pygas hydrotreater. Contaminants can be detrimental to the process, resulting in such operational problems as accelerating coke formation, corrosion, catalyst poisoning, fouling of major equipment, over-consumption of utilities such as steam in the benzene stripper, among others.

Typical contaminants include various liquid impurities (of aqueous and organics), particulate solids (such as coke fines, salts, and corrosion products), deformable semi-solids (of tar-like high molecular weight compounds) and gases (including hydrogen sulfide, carbon dioxide, and air in the compressor lube oil).

An effective removal of contaminants at any point of entry into the process (such as feed stocks and burner fuels) as well as those generated within the process is of paramount importance to effectively protect the downstream equipment critical to the ethylene production and to prevent high OPEX, low productivity and energy inefficiency to ultimately meet the performance expectations and the production capacity.

This tutorial session reviews the criticality of fluid cleanliness in the ethylene process. It describes the various filtration and phase separation solutions that can be applied in various locations within the process to mitigate the operational problems associated with the presence of impurities by removing them from liquid and gaseous streams within the production process.

The most cost-effective options achieving a suitable removal of contaminants with the highest degree of separation and potential benefits will be highlighted. Furthermore, general guidelines will be discussed for effectively selecting and specifying an optimum filter for a particular application.