Extrel在环氧乙烷生产工艺中的应用.doc

Application of a Quadrupole Mass Spectrometer in the Control of Ethylene Oxide Production Dr. Zbigniew T. Krieger, Extrel CMS, LLC, Pittsburgh, USA Abstract Since mid seventies, mass spectrometry has been used in petrochemical industry to monitor chemical processes and environment conditions. Many successful applications developed, like fermentation, steel, ammonia, VCM/EDC in air. In case of ethylene oxide production, traditional measurement of major compounds in and out of the reactor has been utilized for some time. With high accuracy of quadrupole mass spectrometers, precise calculations of oxygen and carbon balances together with a variety of other process parameters allowed the manufacturer to improve process efficiency and stay within the safe levels of operation. However, it has been known that the activity of catalyst needs to be kept under control by injecting a measured amount of chlorinated hydrocarbons. Process gas chromatographs have been used to measure the chlorides at sub-PPM level. The relatively slow analysis offered by gas chromatographs (minutes) did not allow the direct control of the process within a very thin range of tolerance. Only recently, process quadrupole mass spectrometers offer an excellent analysis of major compounds combined with fast a reliable analysis of chlorides (seconds instead of minutes). This article will present the quadrupole mass spectrometer's application on the ethylene oxide process control, emphasizing the sub-PPM level of chlorides. ......