(82c) Cost Effective Control of Red Oil in Caustic Tower Systems

Cost Effective Control of Red Oil in Caustic Tower Systems

Authors:               Kyle David Mankin          Global Marketing Manager- Petrochemicals

P. N Ramaswamy,           Global Technical Director

Saurabh Shende,             Technical Manager – Petrochemicals

Abstract:

In the modern era, the economics for producing olefins have become more of a challenge. To maximize profit, ethylene crackers are being asked to process “opportunity naphtha’s” or other liquid feeds which are available at advantaged pricing.   Often, these feeds contain elevated levels of sulfur which lead to higher production of H2S in the furnaces.  In some regions, producers are also turning to new technology for producing olefins from methanol.   These drastic design changes are creating challenges in the operations of normal caustic tower systems, which are critical for the removal of contaminants like H2S and CO2 which are generated in furnaces.

One of the most frequent causes of mal-operation in a caustic tower system is the excessive formation of red oil polymer.  Red oil polymer is generated due to Aldol condensation of carbonyl compounds including a mix of various ketones and aldehydes.    Conventional treatments for control of red oil formation have focused on the reduction of aldehydes to alcohols or dispersing the polymers after they are formed.  Dorf Ketal has developed a patented new technology that inhibits polymer formation while also scavenging polymer molecules already in existence.  With this new approach, our chemistry is effective even when applied in sub-molar ratios, thus reducing the treatment cost without sacrificing efficiency.

This paper will focus on the sources and mechanisms of fouling in a caustic tower system and will show examples of the effectiveness of our innovative new treatment program including a review of data and experience from a customer operating a 900 KTA Ethylene facility.