Carbon Disulfide Removal to Help Meet New Specifications for Petrochemical Grade Naphtha

Ethylene producers have linked carbon disulfide (CS₂) in petrochemical grade naphtha (PCN) to corrosion in locations downstream of the cracker and to deterioration of pygas hydrogenation catalyst activity. This has led some producers to implement very low specifications (ppm levels) of CS₂ in petrochemical grade naphtha. Other customers have also indicated CS₂ as a primary contaminant particularly in some shale derived feedstocks. Thus CS₂ contamination can effectively limit feedstock flexibility and associated costs. Adsorptive removal of CS₂ represents an economically attractive solution.

To help meet this growing need, Honeywell UOP have developed a new adsorbent, Molsiv CS2-100, for CS₂ removal from petrochemical grade naphtha/NGL. The new adsorbent can remove CS₂ efficiently thereby upgrading PCN/NGL feeds. Extensive pilot plant testing with a variety of commercial feeds has been conducted to demonstrate economic viability of an adsorptive solution. Discussion will focus on Honeywell UOP’s technology offering using the CS2-100 molecular sieve adsorbent that can selectively remove CS₂ from straight run naphtha/NGL streams to help meet the needs of PCN suppliers and ethylene producers.