COMBUSTION IN ETHYLENE PRODUCTION

The quality of the raw ethane feedstock, particularly if obtained from natural gas, is critical. Thus the feed gas quality is monitored for high levels of carbon monoxide( CO) and to maintain a consistent feed to the cracking unit by the SERVOTOUGH SpectraExact 2500 and SpectraScan 2400

1. As carbon dioxide( CO 2) can freeze out on the process equipment at the‘ cold end’ of the operation, it is removed to levels of less than 100ppm( typically 10ppm) in the treatment plants. The SpectraExact

2 is used to monitor the feed treating for CO 2 removal.

After any recycled ethane is blended with the treated feed, a SpectraScan measurement 3 maintains a consistent feed to the cracking unit. The SpectraScan and H2Scan 4 5 maintain constant fire and heating rates of the steam boiler and cracking unit, with a real time, low maintenance BTU analysis, especially when tail gases rich in hydrogen( H 2) and methane( CH 4) are recycled to the burners.

Another important process measurement is the monitoring of the oxygen in cracking furnace combustion gases, where optimized combustion and reduced fuel consumption is achieved by both detailed fuel analysis and rapid flue gas analysis. The SERVOTOUGH FluegasExact 2700 6 and 8, provides analysis of both oxygen( O 2) and combustibles( COe), while an in-situ TDL measurement by the SERVOTOUGH Laser 3 Plus Combustion

7, offers an average path analysis of O 2 across the furnace.

4900

O 2

, CO, NO X, SO X

12

4900

O 2

& NO

11

49

O 2

P12