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