Process for controlling hydrocarbon steam cracking system using a spectrophotometer
OwnerPierre G. Crouzet, Andre J. Martensinventors
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Abstract
The present invention relates to a process and an apparatus for steam cracking a mixture of hydrocarbons comprising passing steam and the mixture of hydrocarbons through at least one heated cracking tube. The process is characterised in that it is controlled by analyzing the mixture of hydrocarbons fed to the cracking tube with an infrared spectrophotometer to determine the absorbances at a number n of wavelengths in the range 0.8 to 2.6 microns and by using the results of this absorbance to determine one or more values V of steam cracking process conditions which will achieve a desired value P of the space time yield of one or more products of the steam cracking reaction.
Claims16
A process for steam cracking a mixture of hydrocarbons comprising passing steam and the mixture of hydrocarbons through at least one heated cracking tube maintained at cracking reaction conditions wherein the process is controlled by (a) using a spectrophotometer to measure n absorbances of the mixture of hydrocarbons fed to the cracking tube, wherein n is at least two, wherein each absorbance is measured at a wavelength in the range from 0.8 to 2.6 microns, (b) choosing at least one condition of the cracking reaction, and using the n absorbance measurements R.sub.i to determine at least one value V of the at least one of the conditions of the cracking reaction said value V being determined through a correlation relationship, said correlation relationship connecting the n absorbance measurements Ri with a desired space time yield P of one or more products of the cracking reaction and with the value V and (c) controlling the process to operate at the determined value (s) V in order to obtain the desired space time yield P.
A process for steam cracking a mixture of hydrocarbons, in order to control at least one space time yield of one or more products of the steam cracking reaction at a desired value P, the process comprising:
- (a) feeding steam and the mixture of hydrocarbons through at least one heated cracking tube maintained at cracking conditions,
- (b) measuring by means of a spectrophotometer n absorbances of the mixture of hydrocarbons at n wavelengths chosen in the near infrared region of the spectrum from 0.8 to 2.6 microns, n being at least 2,
- (c) choosing at least one condition of the cracking reaction and determining a value V of the at least one condition of the steam cracking reaction directly from the n absorbance measurements, Ri, by means of a correlation relationship, said correlation relationship connecting the n absorbance measurements, Ri, with the at least one desired space time yield P and with the at least one condition V,
- (d) measuring the at least one condition, and
- (e) adjusting the at least one condition to the determined value V in order to obtain the desired value P of the at least one space time yield.
Dependencies are inferred from the claim text.