Troubleshooting jet-fuel production on crude distillation unit in Pemex Cadereyta Refinery

摘要

This paper shows the troubleshooting and analysis that led to a successful modification on thejet-fuel draw-off tray of a crude distillation tower. The modification solved a problem of yieldreduction and difficulties to maintain product specifications.The problem was reviewed qualitatively and quantitatively using different methods proposed byfamous authors in this field like Kister and Lieberman. We used process simulators, heat andmaterial balances, mechanical drawings of tower internal construction, and flow sketchesthrough sections inside the tower. By the use of these tools and the recommended bibliographywe solved the problem and evaluated the modification after plant turndown.The modification of the jet-fuel chimney tray allowed an enhanced performance, a more stableoperation for tower profile control, and an increase in the naphtha yield by 1.2% and jet-fuel by8.3%. All this led to an improvement on plant preheat train thermal stability which gave energysavings of around 5.4 MMUSD per year.Due to the improved crude preheat resulting from the modification, a better desalting isachieved, the pre-flash tower takes more lights off the crude, which allow a better pressurecontrol on atmospheric tower. A large reduction in fuel gas in fired heaters was achieved becauseof the increase in heater inlet temperature.Yield increase of naphtha allows earnings of around 54.3 MMUSD per year. In addition, apotential jet-fuel earning could be achieved because of the production increase, which represents55.3 MMUSD per year.