Method for verification of constituents of a process stream just as they go through an inlet of a reaction vessel

• US 5,412,465 A
• Filed: 08/02/1993
• Issued: 05/02/1995
• Est. Priority Date: 08/02/1993
• Status: Expired due to Fees

• Current Assignee: Energy Department of United States of America
• Original Assignee: United States Department of Energy
• Inventors: Buchanan, Bruce R., O'Rourke, Patrick E., Baylor, Lewis C.
• Primary Examiner(s): Evans, F. L.
• Assistant Examiner(s): VIERRA EISENBERG, JASON D
• Application Number:
  US08/100,162
• Time in Patent Office: 638 Days
• Field of Search: 356/301, 356/300, 356/303, 356/319, 356/326, 356/410, 364/498, 364/497, 110/185, 110/186, 110/188, 110/235, 110/237, 436/104
• US Class Current: 356/301
• CPC Class Codes: G01N 2021/651 Cuvettes therefore
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 21/85 Investigating moving fluids or granular solids

Abstract

A method for validating a process stream for the presence or absence of a substance of interest such as a chemical warfare agent; that is, for verifying that a chemical warfare agent is present in an input line for feeding the agent into a reaction vessel for destruction, or, in a facility for producing commercial chemical products, that a constituent of the chemical warfare agent has not been substituted for the proper chemical compound. The method includes the steps of transmitting light through a sensor positioned in the feed line just before the chemical constituent in the input line enters the reaction vessel, measuring an optical spectrum of the chemical constituent from the light beam transmitted through it, and comparing the measured spectrum to a reference spectrum of the chemical agent and preferably also reference spectra of surrogates. A signal is given if the chemical agent is not entering a reaction vessel for destruction, or if a constituent of a chemical agent is added to a feed line in substitution of the proper chemical compound.

Claims

1. A method for validating a chemical process including reaction of a constituent compound in a reaction vessel, said reaction vessel having an interior and an inlet in communication with said interior, said constituent compound passing through said inlet to said reaction vessel, said constituent compound being altered chemically upon reacting in said reaction vessel, said method comprising the steps of:

directing a light beam into said constituent compound in said inlet just as said constituent compound is entering said reaction vessel;

measuring an optical spectrum of said constituent compound after interaction of said light beam with said constituent compound;

comparing said optical spectrum to a reference spectrum of said constituent compound to determine if said optical spectrum of said constituent compound and said reference spectrum match; and

emitting a first signal when said optical spectrum of said constituent compound matches said reference spectrum to confirm said constituent compound is entering said reaction vessel.

2. The method as recited in claim 1, wherein said directing step further comprises the step of positioning a sensor in said inlet, said sensor carrying said light beam to and from said inlet in optic fibers so that said light beam can be directed through said constituent compound near said reaction vessel.

3. The method as recited in claim 1, wherein said directing step further comprises the step of positioning a sensor in said inlet, said sensor having a housing and carrying-said light beam into said inlet in a first optic fiber and out of said inlet in a second optic fiber, said second optic fiber being spaced apart from said first optic fiber, said first and said second optic fibers connected to said housing, said housing having a hole through which said constituent compound can pass, crossing said light beam as said light passes from said first to said second optic fiber.

4. The method as recited in claim 1, wherein said method further comprises the steps of:

comparing said optical spectrum to a reference spectrum of a surrogate compound to determine if said optical spectrum of said constituent compound matches said reference spectrum of said constituent compound or said reference spectrum of said surrogate compound; and

emitting a second signal when said optical spectrum of said constituent compound matches said reference spectrum of said surrogate compound to alert that said surrogate compound is entering said reaction vessel rather than said constituent compound.

5. The method as recited in claim 1, further comprising continually measuring optical spectra of said constituent compound and comparing said optical spectra to said reference spectrum.

6. The method as recited in claim 1, wherein said measuring step further comprises measuring an absorption spectrum of said constituent compound after said light beam passes through said constituent compound.

7. The method as recited in claim 1, wherein said measuring step further comprises measuring a Raman spectrum of said constituent chemical compound.

8. A method for validating a chemical destruction of a hazardous chemical compound in a reaction vessel, said reaction vessel having an interior and an inlet in communication with said interior, said hazardous chemical compound passing through said inlet to said reaction vessel, said hazardous chemical compound being rendered no longer hazardous upon reacting in said reaction vessel, said method comprising the steps of:

directing a light beam into said hazardous compound in said inlet just as said hazardous chemical compound is entering said reaction vessel;

measuring an optical spectrum of said hazardous chemical compound after interaction of said light beam with said hazardous chemical compound;

comparing said optical spectrum to a reference spectrum of said hazardous chemical compound to determine if said optical spectrum of said hazardous chemical compound and said reference spectrum match; and

emitting a first signal when said optical spectrum of said hazardous chemical compound matches said reference spectrum to confirm said hazardous chemical compound is entering said reaction vessel.

9. The method as recited in claim 8, wherein said directing step further comprises the step of positioning a sensor in said inlet, said sensor carrying said light beam to and from said inlet in optic fibers so that said light beam can be directed into said hazardous chemical compound near said reaction vessel.

10. The method as recited in claim 8, wherein said directing step further comprises the step of positioning a sensor in said inlet, said sensor having a housing and carrying said light beam into said inlet in a first optic fiber and out of said inlet in a second optic fiber, said second optic fiber being spaced apart from said first optic fiber, said first and said second optic fibers connected to said housing, said housing having a hole through which said hazardous chemical compound can pass, crossing said light beam as said light passes from said first to said second optic fiber.

11. The method as recited in claim 8, wherein said method further comprises the steps of:

comparing said optical spectrum to a reference spectrum of a surrogate compound to determine if said optical spectrum of said hazardous chemical compound matches said reference spectrum of said hazardous chemical compound or said reference spectrum of said surrogate compound; and

emitting a second signal when said optical spectrum of said hazardous chemical compound matches said reference spectrum of said surrogate compound to alert that said surrogate compound is entering said reaction vessel rather than said hazardous chemical compound.

12. The method as recited in claim 8, further comprising continually measuring optical spectra of said hazardous chemical compound and comparing said optical spectra to said reference spectrum.

13. The method as recited in claim 8, wherein said measuring step further comprises measuring an absorption spectrum of said hazardous chemical compound after said light beam passes through said hazardous chemical compound.

14. The method as recited in claim 8, wherein said measuring step further comprises measuring a Raman spectrum of said hazardous chemical compound.

15. A method for validating a chemical process for making a product in a facility having a reaction vessel with an interior and an inlet, said inlet being in fluid communication with said interior, said chemical process using a constituent compound, said constituent compound passing through said inlet into said reaction vessel where said constituent compound is altered chemically upon reacting in said reaction vessel, said method comprising the steps of:

directing a light beam into said constituent compound in said inlet just as said constituent compound is entering said reaction vessel;

measuring an optical spectrum of said constituent compound after interaction of said light beam with said constituent compound;

comparing said optical spectrum to a reference spectrum of a hazardous compound to determine if said optical spectrum of said constituent compound matches said reference spectrum; and

emitting a first signal when said optical spectrum of said constituent compound matches said reference spectrum to alert that said hazardous compound is entering said reaction vessel.

16. The method as recited in claim 15, wherein said directing step further comprises the step of positioning a sensor in said inlet, said sensor carrying said light beam to and from said inlet in optic fibers so that said light beam can be directed into said constituent compound near said reaction vessel.

17. The method as recited in claim 15, wherein said directing step further comprises the step of positioning a sensor in said inlet, said sensor having a housing and carrying said light beam into said inlet in a first optic fiber and out of said inlet in a second optic fiber, said second optic fiber being spaced apart from said first optic fiber, said first and said second optic fibers connected to said housing, said housing having a hole through which said constituent compound can pass, crossing said light beam as said light passes from said first to said second optic fiber.

18. The method as recited in claim 15, wherein said method further comprises the steps of:

comparing said optical spectrum to a reference spectrum of a surrogate compound to determine if said optical spectrum of said constituent compound matches said reference spectrum of said hazardous compound or said reference spectrum of said surrogate compound; and

emitting a second signal when said optical spectrum of said constituent compound matches said reference spectrum of said surrogate compound to alert that said surrogate compound is entering said reaction vessel rather than said hazardous compound.

19. The method as recited in claim 15, further comprising continually measuring optical spectra of said constituent compound and comparing said optical spectra to said reference absorption spectrum.

20. The method as recited in claim 15, wherein said measuring step further comprises measuring a spectrum selected from the group consisting of absorption spectra and Raman spectra.