CS218947B1 - Equipment for long-term verification of catalyst activity - Google Patents

Abstract

A device for long-term verification of catalyst activity in liquid phase reactions, consisting of a heating jacket of a sampling vessel divided into an upper and lower section, a reactor tube passing through both sections, equipped with a filter partition for placing the catalyst bed, the upper section being closed by a plug containing an inlet tube and a vent tube, the lower section containing an overflow tube for the outflow of the reaction mixture and a safety overflow tube connecting both sections. Suitable for verification of catalyst activity in laboratory and industrial production with the possibility of being connected to series-connected reactors.

Description

SUMMARY OF THE INVENTION The present invention provides laboratory equipment for the long-term verification of catalyst activity in liquid phase reactions.

Liquid phase reactions are often catalyzed by heterogeneous catalysts. One of the basic types of reactors for carrying out such reactions is a reactor with a fixed catalyst bed through which the liquid flows, from top to bottom. The catalyst layer is not vortexed in this flow direction and the catalyst particles are therefore not entrained by the leaving reaction mixture. As a rule, the activity of the catalyst decreases as a result of its progressive deactivation, for example by clogging with polymeric or sparingly soluble compounds and the like. Therefore, in order to assess the economics of the studied process, it is necessary to monitor the function of the catalyst in the long term by means of life tests. However, polymeric or sparingly soluble compounds need not only clog the pores of the catalyst, but can also precipitate and settle in the space between its grains and thus gradually increase the hydraulic resistance of the bed.

Long-term monitoring of catalysts on a laboratory scale is very difficult. A long-term attempt can usually not be interrupted daily before the end of working hours, as the flow interruption distorts the data obtained. However, even with the possibility of daily interruption of life tests, the total duration of the experiment is disproportionately extended. On the other hand, it is rarely possible to provide a four-shift operation in the laboratory to supervise such an apparatus.

A typical example of lifetime assays is to monitor the activity of strongly acidic ion exchangers in the condensation of phenols with ketones, as described, for example, in the axis. AO 200 351. - Method for preparing bisphenols. Thus, in the condensation of phenol with acetone to 2,2-bis (4-hydroxyphenyl) -propane in the presence of a strongly acidic cation exchanger, temperatures of 40 to 100 ° C are used, and the cation exchanger activity must be monitored for 500 to 2000 hours or more. is complicated by the fact that, especially at lower temperatures, phenol-dian addition compound readily precipitates both in the cation exchange pores and in the inter-grain gap, resulting in a significant reduction in the throughput of the cation exchange bed over several days of operation.

In laboratory practice, jacketed columns having a fused tap or siphon overflow at the lower end to maintain a constant level above the catalyst bed are commonly used in liquid phase reactions in catalyst practice. A tempering liquid, mostly water, also glycol and the like circulates through the shell. Such an apparatus! however, the arrangement has a number of significant disadvantages. The taps or siphon overflows are difficult to temper to the desired temperature so as not to solidify the reaction mixture at a higher freezing point and at the same time to become unnecessarily overheated in some places, as is common with electric heating tapes. These boxes are not protected against liquid overflow if the throughput of the bed decreases and the level of the bed rises above the bed. The assembly of multi-stage cascades of reactors connected in series is very cumbersome and complicated.

These drawbacks are overcome by the device according to the invention. The laboratory device for the long-term verification of catalyst activity consists in the fact that it consists of two vessels, which are placed one above the other and enclosed in a tempering jacket and connected to each other by a reactor tube in which the catalyst is placed on the filter baffle. wherein the upper vessel is closed by a plug through both the inlet pipe and the venting of the apparatus, the lower vessel is provided with an overflow for withdrawing the reacted reaction mixture and both vessels are equipped with sampling points for liquid sampling both before entering the catalyst layer and after passing through of the catalyst.

An embodiment of the device according to the invention is shown in the attached drawing. The apparatus consists of an upper section 1 and a lower section 2, which are closed by the heating jacket 3 of the reactor vessel. Inside the reactor is located a reactor tube 4 comprising a catalyst bed 6, located in the filter partition 5 and passing through both sections. The inlet tube 8 and the deaeration tube SL pass through the plug 7 of the upper section 1 of the reactor. Both sections are equipped with sampling openings 12, 13. From the upper section 1, the safety overflow pipe Itt extends into the lower section 2.

Device features:

The inlet reaction mixture is fed through an ethoxylated tube 8 to the bottom of the top vessel, section I. Liquid from this section flows into the reactor tube 4, in which the catalyst bed is located on the filter septum 5. 8, the reaction mixture after passing through the catalyst is collected in the lower section 2, from where it flows through the overflow pipe 11 for further processing. in the event that the hydraulic resistance of the catalyst layer rises and the liquid flow through the reactor tube 4 decreases, the level in section 1 rises until the liquid overflows through the overflow safety tube 10 from the upper section 1 to the lower section 2, thereby avoiding equipment failure; all overflows are tempered and thus kept through. Both upper and lower vessels are equipped with sampling points 12, 13 for sampling to determine the composition of the reaction mixture before and after the catalyst bed enters. The whole device can be made of glass, but it can also be made of a suitable metal

213947 material or plastic. Cascade of the described apparatuses into the cascade of series connected reactors does not cause any problems;

Claims (1)

Apparatus for the long-term verification of catalyst activity in liquid phase reactions, characterized in that it consists of a heating jacket (3) of a collection vessel divided into upper (1) and lower (2) sections, a reactor tube (4) passing through both sections, provided with a filter baffle ( 5) for which the long-term throughput and thus the safety of operation are still guaranteed. The invention comprises a catalyst bed (6), the upper (1) section being closed by a plug (7) comprising an inlet pipe (8) and a venting pipe (9), the lower (2) section comprising an overflow pipe (11) for and a overflow pipe (10) connecting the section.