Continuous on-line process control of residua distillation
View Patent ↗Ultrasonic spectroscopy, calorimetry, or thermogravimetric analysis provide measures which correlate with properties of asphaltene complex of petroleum residua which can be used to establish or maintain consistent properties of petroleum residua during blending or to determine immediacy of petroleum residuea to deposition phenomena during pyrolytic thermal treatment.
1. A method of assessing immediacy of a petroleum residuum to formation of coke particles in refinery processing comprising the steps of:
a. providing an ultrasonic waveform generator;
b. thermally treating said petroleum residuum;
c. interacting at least one ultrasonic waveform from said ultrasonic waveform generator with said petroleum residuum;
d. detecting at least one ultrasonic waveform characteristic of said at least one ultrasonic waveform after passing through said petroleum residuum;
e. comparing said at least one ultrasonic waveform characteristic with a predetermined ultrasonic waveform characteristic that correlates to an onset of coke particle formation, wherein said predetermined ultrasonic waveform characteristic is determined for a test sample based on analysis selected from a group consisting of: at least one coke index, precipitation of coke, filtration, gravimetric, asphaltene flocculation titration, p a /C min , ratio of a weight percent of a cyclohexane soluble portion of heptane asphaltenes to a weight percent of heptane asphaltenes, solubility characteristics of asphaltenes, values of a weight percent of a cyclohexane soluble portion of heptane asphaltenes, pyrolysis time, relative viscosity, K S values, K F values, K values, and observing the test sample; and
f. assessing immediacy of said petroleum residuum to formation of coke particles.
2. The method of claim 1 wherein said step (b) comprises thermally treating said petroleum residuum to create a pyrolysis system wherein said petroleum residuum is heated greater than about 650 degrees F. (about 340 degrees C.).
3. The method of claim 1 wherein said step (b) comprises thermally treating said petroleum residuum to generate lighter distillates.
4. The method of claim 1 wherein said step (b) comprises heating said petroleum residuum within the range of between about 480 degrees F. (about 250 degrees C.) and about 650 degrees F. (about 340 degrees C.).
5. The method of claim 1 wherein said step (c) comprises monitoring said petroleum residuum until said at least one ultrasonic waveform characteristic reaches said predetermined ultrasonic waveform characteristic.
6. The method of claim 1 wherein said step (c) comprises delivering pulses of said at least one ultrasonic waveform from said ultrasonic waveform generator to said petroleum residuum.
7. The method of claim 1 or 2 wherein said petroleum residuum is selected from a group consisting of resins, heavy oils, shale oils, coal tars, tar sand bitumen, asphalts, fuel oil that remains after the removal of lighter distillates, oils obtained from shale and oils obtained from tar sand bitumen.
8. The method of claim 1 wherein said step (a) comprises selecting said ultrasonic waveform generator from a group consisting of piezoelectric transducers, electromagnetic acoustic transducers, lasers and intensity modulated lasers.
9. The method of claim 1 wherein said step (c) comprises interacting said at least one ultrasonic waveform having a frequency in the range of about 0.1 MHz to about 200 MHz with said petroleum residuum.
10. The method of claim 1 wherein said step (c) comprises interacting said at least one ultrasonic waveform having a frequency in the range of about 1 MHz to about 3 MHz with said petroleum residuum.
11. The method of claim 1 wherein said step (d) comprises detecting said at least one ultrasonic waveform characteristic of said at least one ultrasonic waveform with an ultrasonic transducer.
12. The method of claim 1 wherein said step (d) comprises the step of applying fast Fourier Transformation to said at least one ultrasonic waveform characteristic.
13. The method of claim 1 or 12 wherein said at least one ultrasonic waveform characteristic is selected from a group consisting of velocity, attenuation, frequency, amplitude, and phase information.
14. The method of claim 1 wherein said step (f) comprises continuously assessing immediacy of said petroleum residuum to formation of coke particles.
15. The method of claim 14 further comprising assessing said at least one ultrasonic waveform characteristic of said petroleum residuum a sufficient number of times in a duration of time to avoid formation of said coke particles during said thermal treatment.
16. The method of claim 1 further comprising stopping said step (b) if said at least one ultrasonic waveform characteristic from said detected ultrasonic waveform equals said predetermined ultrasonic waveform characteristic.
17. The method of claim 14 further comprising continuing said step (b) if said at least one ultrasonic waveform characteristic from said detected ultrasonic waveform does not reach said predetermined ultrasonic waveform characteristic.
18. The method of claim 1 wherein said onset of coke particle formation comprises an existence of coke particles having a size selected from a group consisting of about 10 microns, greater than about 10 microns, about 0.5 microns, about 5 microns, and between about 0.5 microns and about 5 microns.
19. The method of claim 14 wherein said predetermined ultrasonic waveform characteristic is determined by a standard ultrasonic waveform attenuation curve.
20. The method of claim 1 wherein said standard ultrasonic waveform attenuation curve is specific to an ultrasonic instrument and ultrasonic parameters.