Decontamination Process

Abstract

In accordance with the present invention, there is provided a process for the decontamination of a reaction vessel, the process comprising the steps of: injecting a treatment composition and a carrier into the reaction vessel; draining a liquid waste stream from the reaction vessel; and venting a gas stream from the reaction vessel. 20 26 20 49 52 25 J un 2 02 6 2 0 2 6 2 0 4 9 5 2 2 5 J u n 2 0 2 6

Description

TECHNICAL FIELD

[0001] The present invention relates to a process for the decontamination of a reactor vessel. More specifically, the present invention relates to a process for the decontamination of catalytic reactor vessels, particularly those that utilise dehydration adsorbents. In some embodiments of the present invention, the process may include the deactivation of the catalyst media. BACKGROUND ART

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0003] Catalytic reactors are enclosed vessels that are used in processes engineering to carry out a range of chemical processes. A catalyst media is loaded into the reactor and it is contacted with a feed stream under conditions that allow a reaction to be driven. Contact may be undertaken at various temperature and pressure dependent of specific design. Catalytic reactors will typically operate in a continuous manner for extended periods of time. The operation may also include a catalyst regeneration phase. Catalytic reactors may also be used for the extraction of contaminates from a feed gas through adsorption of the contaminates into the catalyst media itself. Such reactors are loaded with a solid catalyst phase through which the feed gas flows.

[0004] Reactor vessels may need to be opened for a variety of reasons, including for statutory inspections or operational repairs. It may also be necessary to unload the spent catalyst media and reload fresh catalyst into a reactor prior it being brought back into operation. In order to safely open the vessel, it must cleared of all contaminants and dangerous materials.

[0005] Following the operation of a catalytic reactor, contaminants may reside in the reactor and within the catalyst media.   Depending on the reaction, the main contaminants are typically, but not limited to: hydrocarbons, H2S, benzenes and pyrophoric iron within the reactor and catalyst. Such materials are obviously dangerous 2026204952   25 Jun 2026 and need to be removed from the reactor or be otherwise neutralized prior to opening the vessel.

[0006] Prior to opening a reactor, it is known to use contaminant liberation processes. The intention of such processes is to remove the majority of contaminants, including hydrocarbons, from the reactor. The contaminant liberation process will typically target a 5% lower explosion level (LEL). A 5% LEL is required to ensure that the reactor will not combust should an ignition source inadvertently be introduced. The contaminant liberation process typically comprises conducting a purge of the reactor using an inert gas, such as nitrogen or argon. Alternatively, the reactor may be flooded with water. The main disadvantage of these methods is that neither water nor the inert gases will react with or neutralise all contaminants, for example H2S or pyrophoric material. Such contaminants will remain in the vessel or the catalyst media, thereby presenting a safety risk when the vessel is opened (exothermic reactions / toxic gas). Additionally, these methods are limited in their ability to remove hydrocarbons bound within the catalyst. Water is not an efficient medium for flushing hydrocarbons and so thousands of litres of water are required to reduce the contaminant levels. Water flooding may also only supress the hydrocarbons which will resurge as the water level is lowered. This contaminated water must then be adequately treated prior to disposal. Similarly, gas purging processes can take days or weeks to complete, stalling operations.

[0007] The present invention seeks to overcome, or at least ameliorate, one or more of the deficiencies of the prior art mentioned above, or to provide the consumer with a useful or commercial choice.

[0008] Each document, reference, patent application or patent cited in this text is expressly incorporated herein in their entirety by reference, which means that it should be read and considered by the reader as part of this text. That the document, reference, patent application or patent cited in this text is not repeated in this text is merely for reasons of conciseness.

[0009] Throughout this specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. 2026204952   25 Jun 2026

[0010] Throughout this specification, unless the context requires otherwise, the word "catalyst" or variations such as “catalyst media”, will be understood to refer to media used in reaction vessels. Such media may be selected to drive a chemical reaction in the reaction vessel. Alternatively, the media may be used in separation or filtration applications.   The term “catalyst” should also be understood to refer to dehydration absorbents. As would be appreciated by a person skilled in the art, dehydration adsorbents are solid media used reactor vessels to remove water from gas streams. Examples of dehydration adsorbents include molecular sieves, silica gels and activated alumina. SUMMARY OF INVENTION

[0011] In accordance with the present invention, there is provided a process for the decontamination of a reaction vessel, the process comprising the steps of: injecting a treatment composition and a carrier into the reaction vessel; draining a liquid waste stream from the reaction vessel; and venting a gas stream from the reaction vessel.

[0012] In one form of the present invention, the carrier is steam. In an alternative form of the present invention, the carrier is water.

[0013] The inventors have found that the carrier for the treatment composition acts to disperse the treatment composition through the reactor vessel to contact at least a substantial portion of the surfaces inside the reaction vessel with the treatment composition. Furthermore, when steam is used as the carrier, the steam can at least partially expand pores of the catalyst, allowing penetration of the treatment composition into the catalyst.

[0014] In one form of the present invention, the process removes at least a portion of hydrocarbons from the reaction vessel. The inventors have found that the injection of the treatment composition into the reaction vessel facilitates the liberation of hydrocarbons. It is understood by the inventors that the treatment composition increases the solubility of hydrocarbons in water, whilst also reducing the surface tension of water. 2026204952   25 Jun 2026

[0015] The inventors have also found that the injection of the treatment composition into the reaction vessel may result in the oxidation of a substantial portion of H2S and pyrophoric species within the reaction vessel. The oxidation process will render these materials harmless.

[0016] In one form of the present invention, the reactor vessel comprises a dehydration adsorbent. The inventors have found that the decontamination process of the present invention is particularly well suited for the decontamination of catalytic reactors used for the dehydration of gas streams. As would be appreciated by a person skilled in the art, such reactors use dehydration adsorbents to remove water from the gas stream. The inventors have found that the decontamination process of the present invention may be used to deactivate these catalysts.

[0017] In one form of the present invention, the process is operated continuously. In an alternative form of the present invention, the process is batch operated.

[0018] In one form of the present invention, the steps of: injecting a treatment composition and a carrier into the reaction vessel; draining a liquid waste stream from the reaction vessel; and venting a gas stream from the reaction vessel, are all performed simultaneously.

[0019] In an alternative form of the present invention, the treatment composition and a carrier are injected into the reaction vessel prior to the steps of: draining a liquid waste stream from the reaction vessel; and venting a gas stream from the reaction vessel

[0020] In one form of the present invention, the reaction vessel is flooded with the treatment composition and the carrier.

[0021] In one form of the present invention, the process further comprises the step of measuring the concentration of one or more contaminants within the reaction vessel. Preferably, the process is performed until the concentration of one or more contaminants within the reaction vessel are below a threshold. 2026204952   25 Jun 2026

[0022] In one form of the present invention, the process further comprises the step of measuring the concentration of one or more contaminants in the liquid waste stream and / or the gas stream. Preferably, the process is performed until the concentration of one more contaminants in the liquid waste stream and / or the gas stream are below a threshold.

[0023] In one form of the present invention, the process further comprises a rinse step. Preferably the rinse step comprises the steps of: injecting steam or water into the reaction vessel; draining a liquid waste stream from the reaction vessel; and venting a gas stream from the reaction vessel.

[0024] The inventors have found that the rinse step can be used to remove any residual treatment composition or contaminants from the reaction vessel.

[0025] In one form of the present invention, the rinse step comprises the step of measuring the concentration of the treatment composition in the liquid waste stream and / or the gas stream. Preferably, the rinse step performed until the concentration of the treatment composition in the liquid waste stream and / or the gas stream is below a threshold.

[0026] In one form of the invention, the carrier and the treatment composition are added to the reaction vessel separately.

[0027] In one form of the present invention, the carrier and treatment composition are mixed prior to injection to the reaction vessel. Preferably, the carrier and the treatment composition are mixed in an injection manifold. The inventors have found that the use of an injection manifold facilitates control of the concentration of the treatment composition in the mixture of carrier and treatment composition. Furthermore, the injection manifold permits the injection of the treatment composition to be ceased for the rinse step to be conducted.

[0028] In forms of the present invention where water is used as a carrier, the treatment composition and water may be mixed in a mixing vessel prior to being injected into the reaction vessel. 2026204952   25 Jun 2026

[0029] In one form of the present invention, the carrier and treatment composition are simultaneously injected into the reaction vessel.

[0030] Preferably, the carrier and treatment composition are injected into the reaction vessel through chemical injection points provided in the reaction vessel.

[0031] In one form of the present invention, the liquid waste stream is drained from the reaction vessel into containment.

[0032] In one form of the present invention, a ventilation system is provided to vent the gas stream. Preferably, the ventilation system is an active ventilation system.

[0033] In one form of the present invention, the vented gas stream undergoes further treatment.

[0034] In one form of the present invention, a positive heat flow out of the reactor vessel is established. As would be appreciated by a person skilled in the art, the contact of certain catalyst with steam or water will cause a heat of adsorption reaction in the catalyst, leading to an increase in the temperature of the reactor vessel. The positive heat flow is established to prevent the internal temperature increasing beyond a threshold. Preferably, the threshold is 400°C.

[0035] In one form of the present invention, the carrier is used to maintain a positive heat flow. In an alternative form of the present invention, a heat absorbent is injected into the reactor vessel. Preferably, the heat absorbent is an inert gas. More preferably, the heat absorbent is nitrogen gas. It is understood by the inventors that the use of an inert gas as a heat absorbent allows for heat to be absorbed and carried out of the reactor vessel.

[0036] In one form of the present invention, the treatment composition comprises a mixture of one or more enzymes and one or more surfactants. Preferably, the treatment composition further comprises one or more oxidizing species.

[0037] In one form of the present invention, the one or more enzymes are selected from the group comprising proteases, amylases, lipases, cellulases, and mixtures thereof.

[0038] In one form of the present invention, the concentration of the one or more enzymes in the treatment composition is between 1 ppm and 500 ppm. 2026204952   25 Jun 2026

[0039] In one form of the present invention, at least one of the one or more surfactants is a non-ionic surfactant. Preferably, the at least one of the one or more surfactants is water soluble. More preferably, at least one of the one or more surfactants is an amine oxide surfactant.

[0040] In one form of the present invention, at least one of the one or more surfactants has the following formula: ch2 CH3-(CH2)n-N=O CH2 Where n = 6 - 20

[0041] Preferably, at least one of the surfactants is chosen from the group comprising lauryl dimethyl amine oxide, stearyl dimethyl amine oxide, myristyl dimethyl amine oxide, and mixtures thereof.

[0042] In one form of the present invention, the concentration of the one or more surfactants in the treatment composition is between 1 ppm and 3000 ppm.

[0043] The inventors have found that a suitable treatment composition is sold by United Laboratories International, LLC under the brand name Zyme-Flow® UN657 or similar.

[0044] As discussed above, steam may be used as the carrier.

[0045] In one form of the present invention, the steam is injected into the reaction vessel at a rate of 1.0 tons / hr to 6 tons / hr.

[0046] Preferably, the temperature of the steam is at least 100 °C.

[0047] In one form of the present invention, the pressure of the steam is atmospheric pressure. In an alternative form of the present invention, the pressure of the steam is above atmospheric pressure. Preferably, the pressure of the steam is between 0 barg and 5 barg.

[0048] In one form of the present invention, the treatment concentration is injected into the reaction vessel at a controlled rate. Preferably, the rate of injection is between 2026204952   25 Jun 2026 1 L / hr and 500 L / hr. More preferably, the rate of injection is between 80 L / hr and 120 L / hr.

[0049] As described above, the process is operated until the concentration of one more contaminants in the liquid waste stream and / or the gas stream are below a threshold.

[0050] In one form of the present invention, the LEL % threshold is 5%. In one form of the present invention, the LEL % threshold is 4%. In one form of the present invention, the LEL % threshold is 3%. In one form of the present invention, the LEL % threshold is 2%. In one form of the present invention, the LEL % threshold is 1%. In one form of the present invention, the LEL % threshold is 0.75%. In one form of the present invention, the LEL % threshold is 0.5%. In one form of the present invention, the LEL % threshold is 0.25%. In one form of the present invention, the LEL % threshold is 0.2%. In one form of the present invention, the LEL % threshold is 0.1%.

[0051] In one form of the present invention, the H2S threshold is 50 ppm. In one form of the present invention, the H2S threshold is 40 ppm. In one form of the present invention, the H2S threshold is 30 ppm. In one form of the present invention, the H2S threshold is 20 ppm. In one form of the present invention, the H2S threshold is 10 ppm. In one form of the present invention, the H2S threshold is 8 ppm. In one form of the present invention, the H2S threshold is 6 ppm. In one form of the present invention, the H2S threshold is 4 ppm. In one form of the present invention, the H2S threshold is 2 ppm. In one form of the present invention, the H2S threshold is 1 ppm.

[0052] In accordance with the present invention, there is provided an apparatus for the decontamination of a reaction vessel, the apparatus comprising: a chemical injection manifold adapted to contact a carrier with a liquid stream, the output of the chemical injection manifold being communicable with a reaction vessel; a drainage means being communicable with a reaction vessel; and a ventilation means being communicable with a reaction vessel. 2026204952   25 Jun 2026 BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which: Figure 1 is a flowsheet depicting a process of process for the decontamination of a reactor vessel in accordance with a first aspect of the present invention; Figure 2 is a plot of the measured contaminant levels during the trial of Example 1; and Figures 3a-3c is a plot of the measured contaminant levels during the trial of Example 2 for each respective reactor. DESCRIPTION OF EMBODIMENTS

[0054] The present invention is not to be limited in scope by any of the specific embodiments described herein. These embodiments are intended for the purpose of exemplification only. Functionally equivalent products, formulations and methods are clearly within the scope of the invention as described herein.

[0055] In Figure 1 there is shown a process for the decontamination of a reaction vessel 10 accordance with the present invention. In the embodiment shown in Figure 1, the process of the present invention is used to decontaminate a catalytic reactor 12. The decontamination process comprises the injection of a mixed stream 14, comprising a mixture of a carrier and a treatment composition into the catalytic reactor 12. As would be appreciated by a person skilled in the art, catalytic reactors are used to undertake various industrial chemical reactions. In such reactors, a solid catalyst is loaded into the catalytic reactor 12 and is contacted with feed reagents to drive a chemical reaction. Such reactors may also be used to remove water from a gas stream. In such applications, the solid catalyst is contacted with feed reagents to drive the adsorption. Dehydration adsorbents are typically used as the solid catalysts. At certain times, access to the interior of the catalytic reactor 12 is required for inspection / maintenance 2026204952   25 Jun 2026 and to replenish the catalyst. In order to access the interior, any harmful or dangerous contaminants must be first removed from the reaction vessel. The process of the present invention is intended to decontaminate such reaction vessels to permit access to the interior. Whilst the present invention is described with reference to catalytic reactors, it is envisaged that it may also be applied to other sealed reaction vessels where toxic or flammable contaminants may be present.

[0056] The inventors have found that the mixture of a carrier and a treatment composition may be used to remove a portion of the hydrocarbons from the reactor vessel. The inventors have also found that the injection of the treatment composition into the reaction vessel may result in the oxidation of H2S and pyrophoric species within the reaction vessel. Furthermore, the injection of the treatment composition into the reaction vessel has been found to deactivate the catalyst.

[0057] The carrier acts to disperse the treatment composition through the reactor vessel to contact at least a substantial portion of the surfaces inside the reaction vessel.

[0058] In a preferred form of the present invention, the carrier is selected from water or steam.

[0059] In the embodiment shown in Figure 1, steam is used as the carrier. A steam stream 16 is obtained from a steam generator 18. As would be appreciated by a person skilled in the art, the steam generator 18 may be selected from any suitable device that can generate the required volume of steam 16. In a preferred form of the invention, the steam generator 18 is a diesel steam generator. Whilst the embodiment shown in Figure 1 depicts the use of a steam generator, it is envisaged that steam may be generated or recycled from any suitable source for use in the process of the present invention.

[0060] A volume of a treatment composition is stored in a holding tank 20. The holding tank 20 is in communication with a chemical pump 22 which is adapted to deliver a treatment composition stream 24 at a controlled rate.

[0061] Both the steam stream 16 and the treatment composition stream 24 are in communication with an injection manifold 26. The injection manifold 26 is adapted to contact the steam stream 16 with the treatment composition stream 24 to produce the 2026204952   25 Jun 2026 mixed stream 14. The injection manifold preferably allows for the volume of the treatment composition stream 24 added to the steam stream 16 to be controlled.

[0062] In the embodiment shown in Figure 1, the steam stream 16 and the treatment composition stream 24 are mixed prior to being injected into the catalytic reactor 12. In an alternative embodiment of the present invention, the steam stream 16 and the treatment composition stream 24 may be injected into the catalytic reactor 12 separately. It is envisaged that the separate streams may be injected into the catalytic reactor 12 in a manner that allows for the mixing of the steam stream 16 and the treatment composition stream 24. This may be achieved by, for example, suitably orientating the injection ports or by injecting the treatment composition stream 24 as small droplets, such as by passing the stream through an atomiser nozzle.

[0063] The steam carries the treatment composition throughout the catalytic reactor 12 to permit the contact of the treatment composition with at least a significant portion of the interior surface of the catalytic reactor 12. As the temperate of the steam reduces, condensation will form within the interior of the catalytic reactor 12 and this will drip down to the bottom of the catalytic reactor 12 towards a drainage means 28. The drainage means 28 will direct any condensate from the catalytic reactor 12 to a storage tank 30.

[0064] A ventilation means 32 is arranged to be in communication with the catalytic reactor 12 to permit gases to be removed from the catalytic reactor 12. The ventilation means 32 allows for the removal of flashed off gases from within the catalytic reactor 12.

[0065] In one form of the present invention, the steam is injected into the reaction vessel at a rate of 1 tons / hr to 6 tone / hr.

[0066] Preferably, the temperature of the steam is at least 100 °C.

[0067] In one form of the present invention, the pressure of the steam is atmospheric pressure. In an alternative form of the present invention, the pressure of the steam is above atmospheric pressure. Preferably, the pressure of the steam is between 0 barg and 5 barg. 2026204952   25 Jun 2026

[0068] In one form of the present invention, the treatment concentration is injected into the reaction vessel at a controlled rate. Preferably, the rate of injection is between 1 L / hr and 200 L / hr. More preferably, the rate of injection is between 80 L / hr and 120 L / hr.

[0069] As discussed above, water may also be used as the carrier. Similar to the discussion above, the treatment composition and the water may be combined prior to the injection into the catalytic reactor. Alternatively, the water and the treatment composition may be injected into the catalytic reactor separately.

[0070] When water is used as a carrier, the water is preferably injected into the reaction vessel at a rate of at least 100 l / hr.   In one embodiment, water is injected into the reaction vessel at a rate of at least 200 l / hr. In one embodiment, water is injected into the reaction vessel at a rate of at least 400 l / hr. In one embodiment, water is injected into the reaction vessel at a rate of at least 600 l / hr. In one embodiment, water is injected into the reaction vessel at a rate of at least 800 l / hr. In one embodiment, water is injected into the reaction vessel at a rate of at least 1000 l / hr. In one embodiment, water is injected into the reaction vessel at a rate of at least 1500 l / hr. In one embodiment, water is injected into the reaction vessel at a rate of at least 2000 l / hr. In one embodiment, water is injected into the reaction vessel at a rate of at least 2500 l / hr. In one embodiment, water is injected into the reaction vessel at a rate of at least 3000 l / hr.

[0071] When water is used as a carrier, the liquid waste stream and the gas stream may be continuously removed from the catalytic reactor. The liquid wasted steam may also be recirculated through the catalytic vessel. Alternatively, the drainage means 28 may be initially closed, to allow the entire vessel to be flooded with the mixture of the treatment composition and the water carrier.

[0072] The treatment composition will preferably comprise a mixture of one or more enzymes. It is understood that the enzymes may be used to degrade oils and hydrocarbons, such as benzene in the reactor. It is also understood that the one or more enzymes will dissolve hydrocarbon binders of solid deposits within the reactor. Solids dislodged from the reactor will also be carried by the condensate to the drainage means. 2026204952   25 Jun 2026

[0073] Suitable enzymes for use in the treatment composition include proteases, amylases, lipases, cellulases, and mixtures thereof.

[0074] The concentration of the one or more enzymes in the treatment composition is between 1 ppm and 500 ppm.

[0075] The treatment composition will preferably comprise one or more surfactants. It is understood by the inventors that the inclusion of surfactants in the treatment composition will assist in the decontamination process in a number of ways. Primarily, the surfactant will allow for the dispersion of oleophilic substances throughout water. As would be appreciated by a person skilled in the art, surfactants contain both hydrophilic and oleophilic groups. The oleophilic groups on the surfactant will attach to a particle of an oleophilic substance (such as oil or hydrocarbon) whilst the hydrophilic group will allow dispersion through water. The surfactants will lower the surface tension between the oil phases and the aqueous phases. As would be appreciated by a person skilled in the art, the reduction is surface tension will facilitate the formation of small droplets of oil throughout the aqueous phase. By this mechanism, oils and other hydrocarbons present in reactor may be emulsified in the condensate and will be removed through the drainage means.

[0076] The surfactants will also lower the surface tension between vapor and liquids. This is important as combustible gases may be more readily liberated from liquids in the reactor. As would be understood by a person skilled din the art, gas may be sufficiently entrained or dissolved in liquids and a reduction in the surface tension will such gases to be liberated from the liquids.

[0077] Preferably, at least one of the one or more surfactants is a non-ionic surfactant or a cationic surfactant.

[0078] The inventors have found that amine oxides are suitable for use as a surfactant in the treatment composition.

[0079] In one form of the present invention, at least one of the one or more surfactants has the following formula: 2026204952   25 Jun 2026 ch2 CH3-(CH2)n-N=O CH2 Where n = 6 - 20

[0080] Preferably, at least one of the surfactants is chosen from the group comprising lauryl dimethyl amine oxide, stearyl dimethyl amine oxide, myristyl dimethyl amine oxide, and mixtures thereof.

[0081] In one form of the present invention, the concentration of the one or more surfactants in the treatment composition is between 1 ppm and 3000 ppm.

[0082] It is understood by the inventors that the treatment composition will increase the solubility of hydrocarbons in water whilst also reducing the surface tension of water. The majority of hydrocarbons in the catalytic reactor 12 will be dissolved in the condensate that forms and be removed from the catalytic reactor 12 through the drainage means.

[0083] In one form of the present invention, the treatment composition may further comprise one or more oxidizing agents. As discussed above, the operation of the reactor will typically result in the formation of toxic H2S and pyrophoric materials, such as iron sulphide. The inclusion of oxidising agents in the treatment composition may be used to convert H2S to safer water-soluble forms of sulphur, such as thiosulphate. The water-soluble sulphides will dissolve in the condensate and will be carried out of the reactor vessel through the drainage means. Furthermore, the oxidising agent can oxidize pyrophoric materials through surface oxidation. The oxidation process will neutralise such pyrophoric materials and the products may be safely disposed of.

[0084] A number of different oxidising agents are available to those skilled in the art. Effective oxidising agents include permanganate, persulfate, sodium nitrite, ozone, hypochlorite and long-chain amine oxides.

[0085] The inventors have found that the process of the present invention is particularly well suited to the decontamination of reactors that use dehydration catalysts, or dehydration absorbents. As would be appreciated by a person skilled in the art, dehydration catalysts exhibit exothermic properties and will heat up when contacted 2026204952   25 Jun 2026 with water, commonly referred to as the “heat of adsorption”. During normal operation of the reactor, the exothermic reaction is regulated by the feed gas, which cools the reaction. However, when the operation of the is ceased in order to allow for the reactor to be opened, the exothermic properties of the catalyst are no longer regulated. Spent catalysts are classified as a class 4 dangerous goods because of their exothermic properties. The inventors have also found that the decontamination process of the present invention will deactivate the dehydration catalyst. Without wishing to be bound by theory, the inventors understand that the formation of water on the surface of the catalyst will be absorbed until it is saturated. Once the dehydration catalyst is saturated, it will it is also deactivated and even if dried, will not regain its ability to adsorb. This allows for the catalyst to be safely handled once the reactor is opened and for it to be disposed of in general waste.

[0086] During the decontamination process, the contact of the carrier and the dehydration catalyst will result in the increase in the internal temperature of the reactor. This temperature is managed by establishing a positive heat flow out of the reactor. In embodiments where water is used as a carrier, the water itself may be used to regulate the internal temperature of the vessel. By increasing the flow rate of the water being injected into the reactor, the temperature may be reduced. Alternatively, the vessel may be flooded to fully saturated the dehydration catalyst.   In embodiments where steam is used as the carrier, a heat absorbent may be passed through the reactor vessel to regulate the temperature of the reactor. The inventors have found that nitrogen gas is particularly useful as a heat absorbent.

[0087] When a reaction vessel, for example a catalytic reactor 12, requires decontamination, the operation of the catalytic reactor 12 ceases and all reagent injection lines disconnected. A drainage means 28 is connected to the discharge of the catalytic reactor 12 and a ventilation means 32 is connected to the vents of the catalytic reactor 12. The discharge of the injection manifold 26 is connected to the chemical injection ports of the catalytic reactor 12. A carrier steam, for example steam stream 16 and the treatment composition stream 24 are similarly connected to the injection manifold 26.

[0088] Initially, the treatment composition stream 24 is closed off at the injection manifold 26 such that the mixed stream 14 comprising only steam is directed into the catalytic reactor 12 to heat the internal surfaces of the catalytic reactor 12. Once a 2026204952   25 Jun 2026 desired internal temperature is reached, the treatment composition stream is opened at the injection manifold and the treatment composition is combined with the steam at a desired injection rate. The mixed stream 14 is injected into the catalytic reactor 12 and condensate and gases are removed from the catalytic reactor 12 by way of the drainage system 28 and the ventilation system 32 respectively. The removed condensate and gases are sampled to monitor the LEL percentage and the content of any other desired contaminants, for example H2S content.

[0089] Once a desired LEL percentage and contaminant content is reached, the treatment composition stream 24 is closed at the injection manifold 26 such that the mixed stream 14 comprises only steam to rinse any remaining treatment composition from the catalytic reactor 12. Steam is directed into the catalytic reactor 12 for a desired period of time, typically 1-2 hours and the condensate is sampled to monitor the concentration of the treatment composition. Once the concentration is reduced to a desired amount, the injection manifold 26 may be shut off and the connections are removed. The catalytic reactor 12 may then be opened. Example 1

[0090] A trial was undertaken to determine the effect that a mixture of steam and a treatment composition had on a spent catalyst material.

[0091] In order to undertake this trial, 8.0 m3 of spent molsieve media (UOP Molecular Sieve-38 1 / 8 / Molsiv Adsorbents RK-38 1 / 16) was obtained. The molsieve media was loaded into a 10.0 m3 container to simulate a catalytic reactor. A steam sparge outlet was installed at the bottom of the container and was connected to an injection manifold. A 1.0 mW containerised boiler was connected to an input of the injection manifold.

[0092] 200 litres of a treatment composition was provided in a chemical storage container. For the purposes of this trial, the selected treatment composition was Zyme-Flow UN657 obtained from United Laboratories International, LLC. The chemical storage container was connected to another input of the injection manifold. A liquid drain of the container was connected to a condensation collection container. A vent line was connected to the container to capture gases that evolve. A MultiRAE 4 gas PID meter was positioned in the vent line to take reading of the evolved gases 2026204952   25 Jun 2026

[0093] In order to commence the procedure, the 2 tonne steam boiler was lit and was brought up to pressure (5-10 bar). The steam line was opened and steam was directed into the container. This was continued until the internal surfaces of the container had reached 100 °C. Once the temperature has been reached, injection of the treatment composition into the steam stream was commenced at a rate of 10 L / hr.

[0094] The LEL%, H2S concentration and volatile organic compound (VOC) concentration in the vented gases were monitored. Once 0% LEL; 0ppm H2S; and 0ppm VOC was obtained, the treatment composition injection was ceased. Steam continued to be rinsed through the container for a further 2 hours. Once completed, the boiler was turned off and the container was allowed to cool.

[0095] Table 1 shows the concentration of various gases liberated from the commencement of steaming and through to the completion of the rinse process. Table 1: Concentration Results Sample Time interval (hrs) Co voc LEL H2S Zymeflow (Its / Hour) ;Temp Top i (oC) ; Temp : bottom i (°C) Comments 1 1 220.0 0.1 23.0 7.1 0 : 27.0 : 27.0 Sample test results on arrival 2 0 33.0 11.4 16.0 4.8 0 I 27.0 I 27.0 Started injecting steam intocontainer 3 1 52.0 199.9 48.0 5.0 0 i 41.0 i 80.0 Increased steam by 1 / 8 turn 4 2 72.0 199.9 69.0 6.0 10 I 72.0 I 100.0 Tempratue increasing Added zymeflow 5 3 10.0 199.9 15.4 8.7 10 I 90.0 I 101.0 6 4 14.0 176.9 7.0 8.5 10 i 109.0 i 101.0 7 5 8.0 150.0 5.0 3.7 10 I 120.0 I 101.0 8 6 3.0 82.3 0.0 3.5 10 i 122.0 i 101.0 9 7 0.0 14.6 0.0 2.2 10 i 120.0 i 101.0 10 8 0.0 19.0 0.0 1.1 10 i 115.0 i 101.0 11 9 0.0 9.8 0.0 0.0 10 : 105.0 : 101.0 All readings are dropping 12 10 0.0 0.0 0.0 0.0 10 i 102.0 i 100.0 iStopped Zymeflow 13 11 0.0 0.0 0.0 0.0 0 I 101.0 I 100.0 14 12 0.0 0.0 0.0 0.0 0 ; 101.0 ; 101.0 15 13 0.0 0.0 0.0 0.0 0 : 100.0 : 101.0 Stopped test

[0096] A plot of these results is shown in Figure 2.

[0097] Results from the trial confirm theory and expectations that it is possible to decontaminate, deactivate and neutralise spent media utilising steam and a treatment composition. From the time the bed attains 100 °C and commencement of treatment composition injection, complete removal of LEL, H2S, and VOC’s is achieved within 7 hours.

[0098] The method of the present invention has been shown to be more efficient than traditional methods for decontamination that utilise N2 purging and water flooding. As would be appreciated by a person skilled in the art, such methods can take up to 3 - 4 2026204952   25 Jun 2026 days, producing less satisfactory results. Furthermore, when water flooding is used, hundreds or thousands of litres of hydrocarbon contaminated effluent is produced Example 2

[0099] A decontamination trial was conducted on three molecular sieve dehydrators used in a GLNG Train. Due to the nature of the zeolite dehydration adsorbent used in these reactors, deactivation of this material was required.

[00100] Steam was supplied by 3 x 2.7 ton / hr 10bar temporary boilers to the nominated steam and chemical injection points

[00101] 6 x 200 litres of a treatment composition was provided in a chemical storage container. For the purposes of this trial, the selected treatment composition was Zyme-Flow UN657 obtained from United Laboratories International, LLC.

[00102] Steam was injected into each reactor. The catalyst caused the temperature to initially rise, but then temperature fell and plateaued upon deactivation on the catalyst. Steam was injected until target temperature of 120°C is verified at the vessel outlet and steam flow at outlet is confirmed.

[00103] Steam injection was maintained to a target temperature of 115°C - 125°C. Injection of the treatment composition was commenced at an injection rate of 20 - 40 lph. The levels of LEL, H2S, Hg and Benzene was monitored at the vent sample point and the results for each reactor are plotted in Figures 3a - 3c. Treatment composition injection was continued until LEL 0%, H2S 0ppm and benzene <1ppm (or ALARP).

[00104] Steam injection continued to rinse out the reactor vessel for 1 hour. LEL, H2S, Hg and Benzene levels were monitored. Details results are shown in Table 2, with a contaminant summary provided in Table 3. 2026204952   25 Jun 2026 Table 2: Detailed contaminant Analysis Analyte grouping / Analyte CAS Number Unit Limit of repotting EP068B: Organophosphorus Pesticides (OP) Bromophos-ethyl 4824-78-6 mg / kg r 0.05 <0.05 <0.05 Fenamiphos 22224-92-6 mg / kg r 0.05 <0.05 <0.05 Prothiofos 34643-46-4 mg / kg T 0.05 <0.05 <0.05 Ethion 563-12-2 mg / kg r 0.05 <0.05 <0.05 Carbophenothion 786-19-6 mg / kg r 0.05 <0.05 <0.05 Azinphos Methyl 86-50-0 mg / kg r 0.05 <0.05 <0.05 EP080 / 071: Total Petroleum Hydrocarbons C6 - C9 Fraction mg / kg r 10 <10 F 962 CIO - C14 Fraction mg / kg r 50 <50 F 47000 Cl 5 - C28 Fraction mg / kg r 100 <100 <100 C29 - C36 Fraction mg / kg r 100 <100 <100 CIO - C36 Fraction (sum) mg / kg r 50 <50 F 47000 EP080 / 071: Total Recoverable Hydrocarbons - NE PM 2013 Fractions C6 - CIO Fraction C6_C10 mg / kg r 10 <10 F 1290 C6 - CIO Fraction minus BTEX (Fl) C6_C10-BTEX mg / kg r 10 <10 F 1180 >C10 - C16 Fraction mg / kg r 50 <50 F 37500 >C16 - C34 Fraction mg / kg r 100 <100 <100 >C34 - C40 Fraction mg / kg r 100 <100 <100 >C10 - C40 Fraction (sum) mg / kg r 50 <50 F 37500 >C10 - C16 Fraction minus Naphthalene (F2) mg / kg r 50 <50 F 37500 EP080: BTEXN Benzene 71-43-2 mg / kg r 0.2 <0.2 F 23.6 Toluene 108-88-3 mg / kg r 0.5 <0.5 F 62.7 Ethylbenzene 100-41-4 mg / kg r 0.5 <0.5 F 4.8 meta- & para-Xylene 108-38-3 106-42-3 mg / kg f 0.5 <0.5 F 17.9 ortho-Xylene 95-47-6 mg / kg 0.5 <0.5 1.9 Total Xylenes mg / kg 0.5 <0.5 19.8 Sum of BTEX mg / kg f 0.2 <0.2 111 Naphthalene 91-20-3 mg / kg f 1 <1 <1 Table 3: Dehydrator Atmospheric Test Results Pre and Post Decontamination Dehydrator bed LEL % HaS mg / L VOC mg / L Benzene mg / L S tart Peak Start Peak Start Peak Start Peak A 99 99 0 99 0 198 0 0 B 49 99 0 46 0.3 26 0 0 C_______________ 99 99 1.9 99 0 12 0 Post Decontamination of reactors Allowable Limit 5.0 10.0 10.0 1.0 A 0.0 0.0 0.0 0.0 B 0.0 0.0 0.0 0.2 C_______________ 0.0 0.0 0.0 0.1

[00105] The results indicated that the decontamination process of the present invention successfully removed of hydrocarbons, benzene, VOCs, H2S, and pyrophorics from the reactor vessel, allowing safe removal of media and vessel entry.

Claims

1. A process for the decontamination of a reaction vessel, the process comprising the steps of:injecting a treatment composition and a carrier into the reaction vessel;draining a liquid waste stream from the reaction vessel; andventing a gas stream from the reaction vessel.

2. A process according to claim 1, wherein the carrier is selected from steam or water.

3. A process according to claim 1 or 2, wherein the steps of:injecting a treatment composition and a carrier into the reaction vessel;draining a liquid waste stream from the reaction vessel; andventing a gas stream from the reaction vessel,are all performed simultaneously.

4. A process according to any one of the preceding claims, wherein the process further comprises the step of measuring the concentration of one or more contaminants within the reaction vessel.

5. A process according to claim 4, wherein the process is performed until the concentration of one or more contaminants within the reaction vessel are below a threshold.

6. A process according to any one of the preceding claims, wherein the process further comprises the step of measuring the concentration of one or more contaminants in the liquid waste stream and / or the gas stream7. A process according to claim 6, wherein the process is performed until the concentration of one more contaminants in the liquid waste stream and / or the gas stream are below a threshold.2026204952   25 Jun 20268. A process according to any one of the preceding claims, wherein the process further comprises a rinse step.

9. A process according to claim 8, wherein the rinse step comprises the steps of: injecting steam or water into the reaction vessel;draining a liquid waste stream from the reaction vessel; andventing a gas stream from the reaction vessel.10.A process according to any one of the preceding claims, wherein the carrier and the treatment composition are mixed prior to injection to the reaction vessel.11.A process according to any one of claims 1 to 9, wherein the carrier and the treatment composition are added to the reaction vessel separately.12.A process according to any one of the preceding claims, wherein the treatment composition comprises one or more enzymes.13.A process according to any one of the preceding claims, wherein the treatment composition comprises one or more surfactants.14.A process according to any one of the preceding claims, wherein the treatment composition further comprises one or more oxidizing species.15.A process according to any one of the preceding claims, wherein the reaction vessel is a catalytic reactor.16.A process according to claim 15, wherein the reaction vessel comprises a dehydration adsorbent.17.A process according to any one of the preceding claims, wherein the process deactivates a catalyst media.18.An apparatus for the decontamination of a reaction vessel, the apparatus comprising:2026204952   25 Jun 2026a chemical injection manifold adapted to contacting a carrier stream with a liquid stream, the output of the chemical injection manifold being communicable with a reaction vessel;a drainage means being communicable with a reaction vessel; anda ventilation means being communicable with a reaction vessel.

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