NOX PEMS EXPERIENCE ON OPERATING ETHYLENE FURNACES

The Phillips 66 Sweeney Refinery and Petrochemical Complex is a highly integrated complex consistingof refining, chemicals, and ethylene uni ts. The Complex received a Texas Natural Resource Conservation Commiss ion (TNRCC) Flexible Permit to install predictive emissions monitors ( PEMS) at eight furnaces of Ethylene Unit 22. Unit 22 produces approxim ately 1.8 million pounds per day of ethylene. Hydrogen in the fuel gas fluctuates between 20% and 80% depending on economics and the operati onal status of upstream and downstream units. Maintaining consistent f uel gas hydrogen levels and unit upsets made it difficult to train the models. The PEMS is certified and has been in full operation since Ma rch 1996. The difficultes and successes of the PEMS certification proc ess is discussed in this paper.