WO2018141694A1

WO2018141694A1 - Method for passivating a catalyst

Info

Publication number: WO2018141694A1
Application number: PCT/EP2018/052157
Authority: WO
Inventors: Lothar Karrer; Steffen Wagloehner; Stefan Kuhn; Inna SCHWABAUER; Barbara Wucher; Marie-Christine WAGENER; Sven GOEDELMANN; Frank SCHARFENBERGER
Original assignee: Basf Se
Priority date: 2017-01-31
Filing date: 2018-01-29
Publication date: 2018-08-09

Abstract

The invention relates to a method for passivating a catalyst (K1) that contains elemental copper contains and is located in a device (V1). Due to introduction of a sufficient quantity of water into the device (V1) the catalyst (K1) is located completely below the surface of the water, wherein a mixture (G1) of passivated catalyst (K1) and water is obtained in the device (V1). The invention further relates to a mixture (G1) that comprises the passivated catalyst (K1) and water.

Description

The present invention relates to a process for passivating a catalyst (K1) containing elemental copper and contained in a device (V1). By introducing a sufficient amount of water into the device (V1), the catalyst (K1) is completely below the water level, wherein in the device (V1) a mixture (G1) of passivated catalyst (K1) and water is obtained. Furthermore, the present invention also relates to a mixture (G1) comprising the passivated catalyst (K1) and water.

EP-A 0 01 1 150 relates to a process for the preparation of methanol by reacting hydrogen, carbon monoxide and carbon dioxide and / or water vapor and / or oxygen in the presence of catalysts containing zinc, copper and aluminum, and to a process for the preparation of a corresponding catalyst. Here, a special catalyst is used from a mixed crystal containing copper, zinc, hydroxide and carbonate in a specific ratio and aluminum hydroxide as a structural promoter. The catalyst is prepared by calcination and reduction at temperatures between 160 and 350 °. As a starting material in the process for the production of methanol, a synthesis gas is preferably used, which was prepared by partial oxidation of hydrocarbons and after the combined C0 ₂ and H ₂ S washes only CO and H ₂ and to which additional steam is added. The catalysts are first reduced with hydrogen prior to carrying out the methanol production process.

EP-A-0 901 982 relates to a process and a catalyst for the steam reforming of methanol, wherein methanol and water are reacted on this catalyst to form hydrogen. The catalyst is produced by precipitating a solution of zinc and aluminum salt with a specific atomic ratio of the zinc and aluminum atoms in the respective salts with subsequent drying and calcination step and dispersing the resulting mixed oxide in an acidic solution of copper and zinc salts. The catalysts obtained include, inter alia, copper oxide. In order to carry out the steam reforming of methanol, the catalysts used are first reduced with hydrogen gas.

As is apparent from the prior art described above, copper-containing catalysts (inter alia) are used in connection with the production, purification or use of synthesis gas. Under syngas understands In general, gas mixtures containing mainly carbon monoxide and hydrogen, moreover, depending on the desired use, other gases such as carbon dioxide, be included. Depending on the manufacturing process or intended use, other terms are sometimes used instead of syngas and / or distinctions made. For example, if synthesis gas is extracted from water and coal, it is also called "water gas." When methane is used as a source, the term "fission gas" is used. Methanol synthesis gas refers to synthesis gas for methanol production, while the term "oxo gas" is used for the hydroforming (or oxo synthesis).

Regardless of the specific use of the synthesis gas copper-containing catalysts are used to purify the synthesis gas. There are numerous, commercially available copper-containing catalysts which usually contain copper oxide (CuO). This is in principle a kind of precursor of the corresponding catalyst, because such a copper oxide-containing catalyst is usually first reduced in the presence of hydrogen, whereby the actual catalyst is obtained, which has elemental copper. Such a catalyst containing elemental copper is also referred to as an "activated (copper-containing) catalyst." Such elemental copper-containing catalysts are used in particular in the Oxogas fine cleaning to remove oxygen and / or sulfur-containing compounds.

Such elemental copper-containing catalysts often have a relatively long lifetime, sometimes significantly more than 5 years. As the operating time increases, however, the catalysts used gradually lose their activity, for example due to deposits of organic compounds such as mercaptans on the catalyst surface and / or the formation of eg inactive sulfides. In addition, the activity of such a copper-containing catalyst can decrease with increasing operating time because the elemental copper is oxidized, at least in small amounts, by contact with (small amounts of) oxygen to copper oxide. This effect occurs in particular when such catalysts are used for the Oxogas fine cleaning. However, such copper-containing catalysts can not be readily removed in practice from the corresponding device, such as a reactor. The activated catalyst containing elemental copper is pyrophoric and can ignite on contact with atmospheric oxygen itself. Even with a careful addition of oxygen, there is a risk that the catalyst / device can heat up very quickly to temperatures above 500 ° C in this highly exothermic reaction. In practice, such (at least partially active) elemental copper-containing catalysts are (completely) passivated or deactivated and subsequently removed from the corresponding apparatus in which a small amount of oxygen (usually not more than 1%) in an inert gas stream (usually nitrogen) is passed over the corresponding catalyst. Due to this careful transfer of a very small amount of oxygen over the catalyst, the elemental copper present on the surface of the catalyst is oxidized to the "unproblematic" copper oxide, thus the corresponding copper catalyst has been converted to its inactive / deactivated form.

A disadvantage of this form of passivation or deactivation of a catalyst containing elemental copper which is frequently used in practice is the relatively long duration of the passivation step due to the highly exothermic reaction upon contact of copper with (air) oxygen. For large-scale applications in which the corresponding catalysts are sometimes used on a ton scale, it takes for sufficient passivation / deactivation of the elemental copper-containing catalyst with the appropriate careful addition of small amounts of oxygen usually several days, often more than a week. Partly because of the sulfur deposits contained in the used catalysts, odor emissions often occur due to the release of hydrogen sulfide and mercaptans.

Due to the amount of oxygen used, however, only the surface of the corresponding catalyst is completely passivated (deactivated) by the formation of copper oxide. Nevertheless, after the passivation, the catalyst has to be removed very carefully from the corresponding device, since, for example, catalyst pellets can break, which in turn "releases" elemental copper into lightning-like reactions with atmospheric oxygen After removal from the corresponding apparatus, the catalyst must be handled with great care and effort, in order to avoid the occurrence of undesired secondary reactions, for which a longer storage in separate containers is generally required in order to remove the removed catalyst with regard to frequently occurring secondary reactions, in particular with atmospheric oxygen. Such storage is time consuming and costly, for example, constant cooling with dry ice is often required.

The present invention has for its object to provide a new method for passivation of a copper-containing catalyst. The object is achieved by a method for passivating a catalyst (K1), wherein the catalyst (K1) contains elemental copper and is in a device (V1), characterized in that in the device (V1) water is introduced, wherein at least as much water is introduced into the device (V1) that after completion of the water introduction into the device (V1) the catalyst (K1) is completely below the water level, whereby a mixture (G1) of passivated catalyst (K1) and water obtained becomes. A significant advantage of the method according to the invention is the fact that it can be carried out very inexpensively and / or quickly. Due to the use of water, the passivation of very large amounts of elemental copper-containing catalysts can be carried out very quickly, for example over a period of one hour or less. Furthermore, it is advantageous that the water used, for example, can penetrate very quickly into the pores of optionally porous catalyst material.

In the process according to the invention, the elemental copper of the activated catalyst is not oxidized to copper oxide due to the use of water, as is the case with the transfer of an oxygen-containing gas stream. Instead, the elemental copper is passivated by the use of water with an "oxygen diffusion barrier" The passivated catalyst thus still contains large amounts of elemental copper, which is, so to speak, under a water protection layer, in which connection the term "phlegmatized copper" can also be used.

In addition, the method of the invention also increases the safety, because there is no risk of sudden strong increase in temperature due to the highly exothermic reaction with a large amount of oxygen. In the context of the process according to the invention, although a temperature increase can likewise be observed when the water is added to the passivation of the catalyst containing elemental copper, this temperature increase is relatively small. The exact values of the respective temperature increase depend in particular on the rate of addition of water during the passivation. The faster the addition of water, the higher the temperature increase (with a constant amount of water). But even in the case of a relatively rapid addition of the complete amount of water (for example, over a period of several minutes to one hour), the observed increase in temperature is relatively low, and is usually a maximum of 50 ° C.

The thus passivated copper-containing catalyst can thus be removed very quickly from the corresponding device, resulting in a significant time and Cost saving represents. The corresponding device can thus be filled in a very fast way again with fresh catalyst, so that the idle or downtime of a large-scale plant can be significantly reduced. Due to the passivation of the copper catalyst under the water-proofing layer, this catalyst can also be temporarily stored in a relatively simple manner. There are no time consuming observation or cooling steps required for this. The only prerequisite for this is that the catalyst is stored in a moist state in a preferably closed container in order to prevent evaporation of the water protection layer. An intermediately stored passivated catalyst can consequently be disposed of in a very simple way. The disposal can take place for example in a special device and / or at another location, for example in the form of a recovery of the copper content.

Likewise, it is conceivable that the passivation of the copper-containing catalyst is carried out reversibly, wherein the water used is optionally separated again from the catalyst in a corresponding separate device. Such a step can be carried out, for example, when the still elemental copper-containing catalyst, which is thus catalytically active, is to be transported in order to reinstall it at another location or in another device and put it into operation. It is likewise conceivable that such a passivation step is carried out in order to change the framework conditions, for example in the case of different synthesis gas compositions, in a reactor, without the catalyst having to be removed from the reactor.

Subsequently, the inventive method for passivating a catalyst (K1) is further specified.

The device (V1) as such is known in principle to the person skilled in the art. In the context of the method according to the invention, in principle any device can be used which is suitable for carrying out a catalytic process, in particular for removing impurities from the synthesis gas, preferably from oxo gas. Furthermore, the device (V1) is preferably suitable for being operated under protective gas, preferably under inert gas. Preferably, the device (V1) contains suitable devices, in particular grids, on which a catalyst can be applied. Furthermore, the device (V1) preferably contains at least one additional inlet, which is mounted at the top, bottom and / or on the side of the device (V1). This at least one additional inlet is preferably suitable for introducing water into the device (V1). In particular, the device (V1) is a reactor. In the device (V1) there is at least one catalyst (K1). The catalyst (K1) contains elemental copper. The catalyst (K1) as such is known to the person skilled in the art.

It is preferred that the catalyst (K1) be prepared in situ in the device (V1) from a corresponding catalyst precursor which, instead of elemental copper, contains copper oxide. The corresponding reduction of copper oxide to elemental copper is also referred to as "activation of the catalyst" or "activation of the catalyst precursor". The reduction of copper oxide to copper, which is preferably carried out with hydrogen, is known to a person skilled in the art. Corresponding catalysts are described, for example, in the prior art mentioned at the outset, and are commercially available from BASF Catalysts, for example under the name Puristar R3-12 or R3-15.

The catalyst (K1) may contain other components in addition to elemental copper. Preferably, the catalyst (K1) contains elemental copper, zinc oxide or aluminum oxide and optionally further components, preferably the catalyst (K1) contains elemental copper, zinc oxide and aluminum oxide.

Furthermore, it is preferred that the catalyst (K1) contains 10 to 60 wt .-% of elemental copper, preferably 15 to 50 wt .-% elemental copper, in particular 18 to 40 wt .-% of elemental copper, based on the total weight of catalyst. Preferably, the catalyst (K1), if present, zinc oxide and / or alumina at least 15 wt .-% and / or at most 90 wt .-%, based on the total weight of the catalyst. Zinc oxide is preferably contained in the catalyst (K1) at 35 to 45% by weight, in particular at 40% by weight.

Furthermore, it is preferred that the catalyst (K1) is present as a powder or shaped body and / or is porous, preferably in the mixture (G1) the pores of the catalyst (K1) are completely filled with water. If the catalyst (K1) is porous, it preferably has a pore volume of at least 200 ml / kg, in particular 300 ml / kg, and / or a BET surface area> 100 qm / g. Furthermore, it is preferred that the catalyst (K1) containing elemental copper was prepared from a catalyst (K2) containing copper oxide, wherein preferably in the catalyst (K2) contained copper oxide by passing a hydrogen-containing gas at least partially, preferably completely , is reduced to elemental copper to give the catalyst (K1). If the copper oxide is reduced only partially to copper, this is done to at least 50%, preferably at least 80%. The degree of reduction can, for example, over Pressure, duration and / or temperature of the addition of the hydrogen-containing gas can be controlled.

Particularly preferably, the catalyst (K2) differs from the catalyst (K1) only in that copper oxide is at least partially, preferably completely, reduced to elemental copper, while all other catalyst components remain unchanged by this reduction step. This difference applies to the state of the catalyst (K1) prior to its use, for example in a process for removing impurities from synthesis gas.

The catalysts (K1) used in the process according to the invention for passivation have preferably been used prior to carrying out the passivation of the corresponding catalyst in a specific catalytic application / process. The corresponding catalysts have preferably been used for a relatively long period of time, for example more than 1 year, preferably more than 5 years, before the process according to the invention for the passivation of the corresponding catalyst (K1) is carried out.

The catalyst (K1) was preferably used as a catalyst before carrying out the passivation in a process in order to separate impurities, preferably in the form of oxygen and / or sulfur-containing compounds, from a mixture (G2); in particular, the catalyst (K1) was formed before the passivation in a process for removing impurities from synthesis gas, preferably from oxo gas.

Depending on the specific catalytic application, the catalyst (K1) contains deposits with increasing operating time, preferably on the surface and / or in the pores of the corresponding (used) catalyst (K1). However, these deposits resulting from the catalytic use are not contained in the above-mentioned catalyst precursor (catalyst (K2)). Preferably, the catalyst (K1) contains deposits of carbonaceous and / or sulfur-containing compounds, preferably the deposits are on the surface and / or in the pores of the catalyst (K1). The abovementioned deposits contain the catalyst (K1), in particular if it has been used in a process for removing impurities from synthesis gas, preferably from oxo gas.

Before the process according to the invention for the passivation of a catalyst (K1) is carried out, it is preferred that the corresponding components, for example starting materials and / or products which are to be purified and which have been passed over the catalyst in the specific catalytic application, at least partially , preferably for the most part, particularly preferably completely, from the corresponding device (V1) are separated or discharged. Such educts and / or products may be, for example, the above-described mixture (G2), preferably the mixture (G2) contains synthesis gas, carbon monoxide, hydrogen and optionally carbon dioxide. Furthermore, the mixture (G2) may also contain hydrocarbons, in addition to the impurities to be separated, such as oxygen and / or sulfur-containing compounds.

After the above-mentioned compounds, which are for example referred to as a mixture (G2), have been separated from the device (V1), the catalyst (K1) remains in the device (V1), after completion of the catalytic application of the catalyst (K1) the device (V1) is generally kept under a protective gas atmosphere, preferably under an inert gas atmosphere, in particular under nitrogen or argon.

Subsequently, the inventive method for passivation of such a catalyst (K1) can be carried out with addition of water, as shown below. The catalyst (K1), which contains elemental copper, is located before the addition of water, first in the device (V1), which is for example under an inert gas atmosphere. The conditions in the corresponding device are designed such that the catalyst (K1) does not come into contact with oxygen, in particular atmospheric oxygen. The catalyst may be applied or attached in the corresponding device, for example on a special device element such as a grid, optionally the catalyst (K1) may also wholly or partially contact the device boundaries such as walls and / or ground. To passivate the catalyst (K1), water is introduced into the corresponding device. By introducing the water into the corresponding device, the water level rises successively, preferably continuously. It is irrelevant whether the introduction of the water from above, from below and / or from the side takes place in the appropriate device. Depending on the geometry of the device limitations, such as floors or walls, and / or the water inlet speed, the corresponding device is successively, preferably continuously, filled with the added water. That is, the more water is added to the device, the higher the water level increases. The water level may optionally also be referred to as the "water surface." In the context of the present invention, the term "completely below the water level" means the following: the minimum amount of water that must be added so that the catalyst (K1) is completely below of Water level is determined by the geometry of the corresponding device and / or the amount of the catalyst (K1). In the present invention, the catalyst (K1) is then completely below the water level in the device (V1), when viewed from the side and / or from the top, no subset of the corresponding catalyst (K1) is located above the water level or sticking out of the water surface. In other words, the catalyst (K1) is then completely wetted by water or enclosed by it. Water can theoretically be introduced into the device (V1) until the corresponding device is completely filled with water, ie the water level is at the upper device limit, for example the lid. Furthermore, it is theoretically conceivable that in addition water is introduced into the corresponding device, wherein the water level can then no longer increase, but that excess water from the corresponding device overflows, or is displaced. It is important to ensure that in the event of overflow of water no catalyst (K1) is flushed out of the appropriate device, because otherwise the washed-out amount of catalyst is in danger of coming into contact with oxygen.

In practice, the addition of the water to the corresponding device is usually stopped when the water level is a few centimeters, for example 1 to 50 cm, above the highest point at which a subset of the catalyst (K1) in the device (V1) is arranged. For example, this highest point may be at the top of a catalyst bed. The height at which the water level after completion of the addition of water exceeds the highest point of the catalyst (K1) in the device (V1) depends in practice also on the dimension of the device (V1) and / or the amount of catalyst (K1) , The more catalyst is to be passivated and / or the larger the device (V1), the higher the distance of the water level to the highest point of the catalyst (K1) in the device (V1).

By introducing the water into the device (V1), in the context of the present invention, the passivation of this catalyst (K1) is achieved, because in the device (V1) a mixture (G1) is formed which contains the passivated catalyst (K1) and Contains water. In order to achieve the passivation, however, at least as much water must be introduced into the device (V1) that after completion of the water introduction, the catalyst (K1) is completely below the water level. Thus, in its passivated state, the catalyst (K1) still contains elemental copper which, in contrast to deactivation processes known from the prior art, uses oxygen-containing streams due to the inventive use of water, is not oxidized to copper oxide. Since the passivation of the catalyst (K1) by means of water and formation of a water protection layer is in principle reversible, the water can be completely or at least partially removed from the mixture (G1) and the passivated catalyst (K1) can optionally be reused.

In addition to the passivated catalyst (K1) and water, further components may optionally be present in the mixture (G1). The other components in the mixture (G1) may be, for example, compounds which have come into contact with the corresponding catalyst from the above-mentioned specific catalytic application of the corresponding catalyst before carrying out the process according to the invention for the passivation of such a catalyst. For example, these may be components which may be present in the mixture (G2), in particular hydrocarbons and / or the impurities to be separated off. It is also possible that with more addition of water in the context of the process according to the invention for the passivation of a catalyst (K1) further components are contained in the water, for example additives for pH regulation. However, if such additional components are added with the water, they are preferably less than 20% by weight, more preferably less than 5% by weight, especially less than 1% by weight. Particular preference is given to using pure water, in particular demineralized water, in the process according to the invention. The introduction of the water into the device (V1) can be done in principle at any speed and / or quantities. Furthermore, it is preferred that the introduction of the water is controlled so that the temperature in the device (V1) does not increase or only very slightly. Furthermore, it is preferred that the device (V1) is flushed before and / or during the introduction of the water by introducing an inert gas, preferably with nitrogen, preferably the inert gas is introduced from above and from below into the device (V1). Furthermore, it is preferred that the device (V1) during the passivation of the catalyst (K1), preferably during the introduction of the water, completely or at least for the most part is oxygen-free. In the context of the present invention, the term "completely free of oxygen" is understood to mean that no oxygen is present in the corresponding device (V1), ie when the oxygen has fallen below the detection limit in the device (V1) only very small residual amounts of oxygen are present, preferably less than 1 ppm. The oxygen freedom is achieved by methods known in the art, for example by the application of vacuum and / or the use of inert gas. It is likewise preferred that the corresponding supply lines or discharges of the device (V1) are kept free of oxygen during the passivation of the catalyst (K1). Likewise, it is preferred that the water used for the passivation is previously freed of oxygen by degassing. Furthermore, it is preferred that the device (V1) is already completely or at least largely free of oxygen as soon as the corresponding specific catalytic application of the catalyst (K1) to be passivated has ended and the corresponding starting materials and / or products to be purified, for example the mixture ( G2), separated from the device (V1) or discharged.

It is likewise preferred in the process according to the invention for the water to be introduced from above into the apparatus (V1), preferably the catalyst (K1) present in the apparatus (V1) is sprinkled with water, the sprinkling of the catalyst (K1) preferably being with water simultaneously with the introduction of an inert gas into the device (V1).

In a preferred embodiment of the method according to the invention, the introduction is carried out until the device (V1) is completely filled with water, and / or the introduction rate of the water is controlled so that the temperature in the device (V1) does not increase or to a maximum 60 ° C increases.

In a further preferred embodiment of the method according to the invention, a subset of the water is separated from the mixture (G1) after completion of the water introduction into the device (V1).

In the context of the method according to the invention, it is preferred that, following the introduction of water into the device (V1), the mixture (G1) is transferred from the device (V1) into a device (V2).

The device (V2) is, in principle, any device known to the person skilled in the art; if appropriate, the mixture (G1) can also be converted into two or more, possibly different devices (V2). Preferably, the mixture (G1) is completely transferred from the device (V1) into the device (V2). The implementation of the transfer as such is known to the person skilled in the art.

If the mixture (G1) is transferred from the device (V1) into a device (V2), it is preferred that i) the mixture (G1) is transferred by suction from the device (V1) into the device (V2), and / or ii) during the transfer of the mixture (G1) into the device (V2) the device (V1) with a Inert gas is purged, and / or iii) during the transfer of the mixture (G1) in the device (V2) further water is introduced into the device (V1), and / or iv) the device (V2) is a container or kettle, preferably a suction carriage is, and / or v) in the device (V2) a subset of the water from the mixture (G1) is separated.

According to the invention, it is further preferred that the device (V1) is filled with fresh catalyst after complete removal of the mixture (G1). In principle, the device (V1) can be filled with any fresh catalyst. However, according to the present invention, it is preferable that the device (V1) be filled with a catalyst conforming to the definitions of the above-described catalyst (K1) and / or (K2), particularly, these catalysts are used for the same purpose after filling with fresh catalyst as the corresponding passivated and / or spent catalyst (K1). More preferably, the fresh catalyst is a catalyst (K2) according to the above definitions from which fresh catalyst (K1) is produced in the apparatus (V1). Preferably, the fresh catalyst (K1) is used as a catalyst in a process for removing impurities, preferably in the form of separating impurities in the form of oxygen and / or sulfur-containing compounds.

Furthermore, it is preferred that after removal of the mixture (G1) and before filling with fresh catalyst, the device (V1) is subjected to a purification and / or excess water is removed from the device (V1). If the passivated catalyst contained in the mixture (G1) is no longer to be reused or, for example because it is consumed, ie not only has sufficient activity, the corresponding mixture (G1) can be finally disposed of after separation from the device (V1) , Methods for carrying out the disposal of copper-containing catalysts are known in principle to the person skilled in the art. The mixture (G1) can in principle also be subjected to such disposal. Preferably, the copper content is recovered from the passivated catalyst (K1) contained in the mixture (G1), preferably in a copper refinery and / or by further processing to copper cable.

A further subject of the present invention is therefore also the mixture (G1), as described above, comprising a passivated catalyst (K1) and water, wherein the catalyst (K1) contains elemental copper and in the mixture (G1) completely below the water level located.

Preferably, the mixture (G1) according to the invention has been prepared by the process according to the invention for the passivation of a catalyst (K1) described above. Furthermore, it is preferred that the catalyst (K1) contains elemental copper, zinc oxide, aluminum oxide and deposits of carbonaceous or sulfur-containing compounds.

In the following, the present invention will be clarified by way of examples.

In the following Examples 1 and 2, in each case the catalyst Puristar R3-12 commercially available from BASF-Catalysts is used. This catalyst contains about 40 wt .-% copper oxide before activation, which corresponds approximately to a proportion of 20 33% of elemental copper after the reduction (activation with hydrogen).

Example 1 relates to a laboratory scale experiment while Example 2 relates to a large scale industrial experiment.

25

In Example 1 (laboratory scale), the corresponding catalyst is first activated in a first step, that is, the copper oxide contained in the catalyst is converted by reduction into elemental copper (preferably completely). Immediately following this first step of Example 1, in a second step, the

Passivation of the elemental copper-containing catalyst according to the invention is carried out by adding water. This means that the corresponding catalyst of example 1 has not been subjected to any practical practical application, for example the removal of impurities from synthesis gas, in the context of this experiment. The absence of a concrete practical application of the

35 corresponding catalyst of Example 1 is irrelevant, because it is nevertheless shown by this experiment that an active catalyst according to the invention can be easily passivated easily passivated with water.

In contrast, the catalyst used in Example 2 in the industrial scale experiment was used to purify synthesis gas for about 7 years before conducting its passivation with water. Before the use of this catalyst in the purification of synthesis gas, he was accordingly to the first step of Example 1 is activated, ie a reduction of copper oxide to copper using hydrogen.

In both examples, after the passivation of the catalyst, a water separation of excess water is carried out. In other words, this means that the amount of water used during passivation of the catalyst (K1) with water is subsequently reduced in the mixture (G1) in a subsequent step. The resulting mixture (G1) of elemental copper-containing catalyst (K1) with a reduced proportion of water is hereinafter also referred to as "water-moist catalyst".

In the following examples, the following abbreviations are also used:

VE (demineralized)

RT (room temperature)

Example 1: Expansion on a laboratory scale

The catalyst R3-12 (5x3 tablets) is reduced, passivated in water, and then a portion of the water is separated. a) reduction:

The catalyst tablets are reduced in the rotary kiln according to the following program:

1 . Stepwise heating (5 ° C per min) from RT to 150 ° C under 5% by volume H ₂ in N ₂ .

2. 1 h hold time at 150 ° C under 5 vol% H ₂ in N ₂ .

3. Heat to 200 ° C (5 ° C per min).

4. Gradually increase the hydrogen concentration to 50 vol% H ₂ in N ₂ within 1.5 h at 200 ° C.

5. 2 h hold time at 200 ° C and 50 vol% H ₂ in N ₂ .

6. Cool to RT under N ₂ atmosphere overnight. b) Passivation with water: 1. The reduced catalyst is transferred under nitrogen into a measuring cylinder, which is modeled on the dimensions of the large reactor (height bed 6 cm, diameter measuring cylinder 3 cm). 2. The measuring cylinder is overlaid with nitrogen by permanent nitrogen dosing via a hose.

3. Subsequently, VE water is added dropwise over 5 minutes via an Ismatec BVP Z pump to completely wet the catalyst with water. After complete addition of the deionized water is reduced

Catalyst (K1) containing elemental copper, completely below the water level in the measuring cylinder used (device (V1)). During the addition, the temperature is monitored via a thermocouple located in the catalyst bed. The maximum temperature reached during the addition is 44 ° C. This corresponds to a temperature increase of

22 ° C.

4. Once the catalyst is completely wetted with water (i.e., the entire catalyst bed in the graduated cylinder is under water), no further temperature increase can be observed. c) Water separation from the catalyst:

A portion of the water is separated from the catalyst via a sieve and the temperature in the water-moist catalyst is controlled for 5 h. No increase in temperature is observed.

Example 2: Removal from a large-scale plant

Initial situation: The system is switched off (depressurised) and the tank is flowed through with nitrogen from below (about 1000 Nm ³ / h) in order to avoid the oxygen input when the reactor lid is opened. At the bottom of the container, a connection for flooding with demineralised water is produced (C-tube, 7 bar pre-pressure).

The reactor (device (V1)) is flooded from bottom to top with demineralised water. In this case, a temperature rise can be observed, which is controlled using a total of five thermocouples. The five thermocouples are arranged evenly from bottom to top over the entire reactor height. Based on the temperature rise of the respective thermocouples, the level can be tracked. The temperature increase increases with each thermocouple and finally reaches a maximum temperature of approx. 50 ° C at the uppermost element. The time to complete filling is about 45 min. After complete addition of the deionized water is the further reduced catalyst (K1) containing elemental copper, completely below the water level in the reactor used, whereby the mixture (G1) is obtained. After the filling process it takes about 2-3 hours until the axial temperature profile has equalized. As soon as the temperature profile is balanced, the catalyst is started. By means of a suction carriage (device V2)), the reactor is sucked from above and transferred the mixture (G1) in the suction truck. Is the suction truck filled.

When unloading from the suction truck, the wet catalyst is separated from a subset of the water and can be reprocessed.

It can be shown from Examples 1 and 2 mentioned above that the passivation of a catalyst containing elemental copper with water can be carried out very quickly both on a laboratory scale and on an industrial scale, with only a very slight increase in temperature.

Claims

claims

A method for passivating a catalyst (K1), wherein the catalyst (K1) contains elemental copper and is in a device (V1), characterized in that in the device (V1) water is introduced, wherein at least as much water in the device (V1) is introduced, that after completion of the introduction of water into the device (V1) the catalyst (K1) is completely below the water level, whereby a mixture (G1) of passivated catalyst (K1) and water is obtained.

2. The method according to claim 1, characterized in that i) the catalyst (K1) contains elemental copper, zinc oxide and aluminum oxide, and / or ii) the catalyst (K1) 10 to 60 wt .-% elemental copper, preferably 15 to 50 wt .-% elemental copper, in particular 18 to 40 wt .-% of elemental copper, based on the total weight of the catalyst, and / or iii) the catalyst (K1) containing elemental copper was prepared from a catalyst (K2) containing copper oxide, wherein preferably the copper oxide contained in the catalyst (K2) is reduced by passing a hydrogen-containing gas at least partially, preferably completely, to elemental copper to obtain the catalyst (K1), and / or iv) the catalyst (K1) as Powder or shaped body is present and / or porous, preferably in the mixture (G1), the pores of the catalyst (K1) are completely filled with water, and / or v) the catalyst (K1) deposits of ko containing compounds containing sulfur and / or sulfur, preferably, the deposits are on the surface and / or in the pores of the catalyst (K1).

3. The method according to claim 1 or 2, characterized in that the catalyst (K1) was used prior to performing the passivation in a process as a catalyst to impurities, preferably in the form of oxygen and / or sulfur-containing compounds from a mixture (G2) In particular, the catalyst (K1) was used prior to carrying out the passivation in a process for the removal of impurities from synthesis gas, preferably from oxo gas.

Method according to one of claims 1 to 3, characterized in that the device (V1) is a reactor.

Method according to one of claims 1 to 4, characterized in that the device (V1) is purged before and / or during the introduction of the water by introducing an inert gas, preferably with nitrogen, preferably the inert gas from above and from below into the Device (V1) initiated.

Method according to one of claims 1 to 5, characterized in that the water is introduced from above into the device (V1), preferably in the device (V1) located catalyst (K1) is sprinkled with water, preferably the sprinkling of Catalyst (K1) with water simultaneously with the introduction of an inert gas in the device (V1).

Method according to one of claims 1 to 6, characterized in that i) the introduction of the water into the device (V1) takes place until the device (V1) is completely filled with water, and / or so controls the rate of introduction of the water is that the temperature in the device (V1) does not rise or rises to a maximum of 60 ° C, and / or ii) after completion of the introduction of water into the device (V1) a subset of the water from the mixture (G1) is separated

Method according to one of claims 1 to 7, characterized in that following the introduction of water into the device (V1), the mixture (G1) from the device (V1) in a device (V2) is transferred.

A method according to claim 8, characterized in that i) the mixture (G1) is transferred by suction from the device (V1) in the device (V2), and / or ii) during the transfer of the mixture (G1) into the device ( V2), the device (V1) is purged with an inert gas, and / or iii) during the transfer of the mixture (G1) into the device (V2) further water is introduced into the device (V1), and / or

5 iv) the device (V2) a container or kettle, preferably a

Saugwagen is, and / or v) in the device (V2) a subset of the water from the mixture (G1) is separated.

10

10. The method according to any one of claims 1 to 9, characterized in that from the mixture contained in the mixture (G1) passivated catalyst (K1), the copper content is recovered, preferably in a copper refinery and / or by further processing into copper cable.

15

1 1. Method according to one of claims 1 to 10, characterized in that the device (V1) after complete removal of the mixture (G1) is filled with fresh catalyst.

12. The method according to claim 1 1, characterized in that the fresh

Catalyst is a catalyst (K2) according to claim 2, option iii), from which fresh catalyst (K1) is produced in the device (V1), preferably the fresh catalyst (K1) is used as catalyst in a process according to claim 3 for separation used by impurities.

25

13. The method according to claim 1 1 or 12, characterized in that after removal of the mixture (G1) and prior to filling with fresh catalyst, the device (V1) is subjected to a cleaning and / or excess water from the device (V1) is removed ,

30

14. Mixture (G1) comprising a passivated catalyst (K1) and water, wherein the catalyst (K1) contains elemental copper and is in the mixture (G1) completely below the water level.

35 mixture (G1) according to claim 14, characterized in that the

Mixture (G1) has been prepared by a process according to any one of claims 1 to 13 and / or the catalyst (K1) contains elemental copper, zinc oxide, aluminum oxide and deposits of carbonaceous or sulfur-containing compounds.