Process for removing hydrocarbons and noxious gasses from reactors and media-packed equipment
A process for quickly removing hydrocarbon contaminants and noxious gases in a safe and effective manner from catalytic reactors, other media packed process vessels and associated equipment in the vapor phase without using steam. The cleaning agent contains one or more solvents, such as terpenes or other organic solvents. The cleaning agent is injected into contaminated equipment, along with a carrier gas, in the form of a cleaning vapor.
1. A method for removing a contaminant from a process system, comprising the steps of:
(i) providing a water-free carrier gas source;
(ii) providing a non-aqueous solvent source;
(iii) volatilizing non-aqueous solvent from the non-aqueous solvent source in water-free carrier gas from the carrier gas source and delivering the carrier gas containing the volatilized non-aqueous solvent to the process system and
(iv) removing said contaminant out of said system, wherein a substantial amount of said contaminant is dissolved in said solvent in a vapor or liquid state as it is being removed from said system.
2. The method of claim 1 , wherein the process system is selected from the group consisting of a reactor, an absorbent chamber containing a molecular sieve, and a pressure vessel.
3. The method of claim 1 , wherein the process system comprises a reactor circuit used in a refining hydrotreating process and associated equipment.
4. The method of claim 1 wherein the carrier gas is at least one member selected from the group consisting of inert gas, purchase fuel gas and hydrogen.
5. The method of claim 1 wherein the carrier gas is at least one dry gas with the chemical formula C n H 2n+2 , wherein n is an integer greater than 0 but less than 6.
6. The method of claim 1 wherein the carrier gas is hydrogen.
7. The method of claim 6 wherein said organic contaminant comprises at least one member selected from the group consisting of crude oil and its derivatives, hydrocarbons and noxious gases.
8. The method of claim 6 , wherein said organic contaminant is a noxious gas, said noxious gas being at least one member selected from the group consisting of hydrogen sulfide, benzene, carbon monoxide, and a light end hydrocarbon, said light end hydrocarbon being capable of resulting in a positive reading when tested for the Lower Explosive Limit (or “LEL”).
9. The method of claim 1 , wherein the carrier gas containing the volatilized solvent is circulated through the system using a compressor.
10. The method of claim 1 , wherein the temperature of the equipment in the system is adjusted to a range of between 225 F and 400 F prior to the introduction of the solvent.
11. The method of claim 1 wherein the solvent is introduced into the carrier gas by connecting the gas and solvent sources.
12. The method of claim 1 wherein the solvent is a non-polar organic solvent.
13. The method of claim 1 wherein the solvent is a C1-C50 hydrocarbon.
14. The method of claim 1 wherein the solvent comprises at least one member selected from the group consisting of aliphatic, paraffinic, isoparaffinic, aromatic, naphthenic, olefinic, diene, terpene, polymeric or halogenated hydrocarbon, and wherein the solvent is a naturally occurring, synthetic or processed organic solvent.
15. The method of claim 1 wherein the solvent is a natural terpene or its hydrogenated derivatives.
16. The method of claim 1 wherein the solvent is a processed solvent selected from the group consisting of an aromatic solvent, virgin naphtha, terpene and hexane.
17. The method of claim 1 wherein the solvent comprises one or more organic compounds.
18. The method of claim 1 wherein the solvent is delivered to the system as a vapor and the volumetric or weight ratio of said solvent vapor and the carrier gas is accurately controlled.
19. The method of claim 18 wherein the weight ratio between said solvent vapor and said carrier gas is in the range of about 0.1 to about 6.
20. The method of claim 18 wherein the weight ratio between said solvent vapor and said carrier gas is in the range of about 2 to about 4.