Practices to Mitigate NOx Risk in the Cryogenic Section of Ethylene Plants

摘要

In May 2010 the Ethylene Producers Committee (EPC) NOx Safety Sub-Committeesponsored a discussion on practices to mitigate NOx risk in the cryogenic section of ethyleneplants. The meeting was attended by representatives of 10 ethylene producers, four ethylenecontractors and other contractors, two additive vendors, and four ethylene industryconsultants. This paper is based on that discussion and explores how the meeting participantsperceive the process safety risk of NOx and strategies deployed to manage that risk. Thediscussion highlighted two common mitigation techniques. The first technique is to preventheavy cracked gas components such as butadiene from entering the coldest sections of thecold box and the second technique is to alcohol wash the cold box during warm-ups. Thepaper compares and contrasts how those techniques are performed.