DD272644A1 - METHOD OF CATALYST ACTIVITY HEALING IN BUTINDIUM 1,4-HYDROGENATION - Google Patents

Abstract

The invention relates to a process for increasing the activity of the nickel-containing hydrogenation catalyst used in the suspension hydrogenation of butynediol-1,4-solution based on alumina and / or silica, which has already suffered a Aktivitaetsverlust by prolonged use. The aim of the invention is to increase this catalyst used in the hydrogenation of 1,4-butynediol solution by simple measures in its activity. According to the invention, the object is achieved by largely suppressing the actual hydrogenation process by reducing the hydrogen pressure for a specific time and then continuing the hydrogenation process after the hydrogen pressure required for the hydrogenation has been restored. As an application example, the suspension hydrogenation of 1,4-butynediol solution using nickel-containing catalyst based on tracer alumina and / or silica in question.

Description

Title of the invention

Catalyst activity enhancement method for butynediol-1,4-hydrogenation

Field of application of the invention

The invention relates to a process for increasing the activity of the nickel catalyst used in the suspension hydrogenation of butynediol-1,4 to 1,4-butanediol and / or 1,4-butanediol or niokelhaltig ^ n Misohkatalysators already suffered a prolonged use loss of activity Has.

TO. 2

Oharal ueristik of the known technical solutions

It is known that 1,4-butynediol may be bydriert in aqueous solution at moderate Wasserstoffdrüoken from 0.5 to 4 MPa and in a temperature range 15-180 ⁰ O suspended using nickel catalysts on alumina support base and / or silicon dioxide. It is also known that these suspension catalysts used for butynediol-1,4-hydrogenation decrease in activity with increasing use time. Therefore, in the past, numerous processes have been developed which aim at reactivating and / or regenerating the inactive catalyst. A process is known for the regeneration of a niokelhaltigen catalyst based on a consisting of acid, refractory oxides carrier, wherein the catalyst was deactivated by nitrogen compounds. The regeneration according to DE-AS 1 667 carried du3? Ch treatment with a mixture of hydrogen and 1 to 50% of hydrogen sulfide at a temperature around 500 ⁰ G. Also known is a process for the regeneration of nickel-aluminum catalysts, by washing with PoIykarbonsäure ( DE-PS 2 147 644). In this process, the catalyst used in the hydrogenation of butynediol and / or butenediol to butanediol as a fixed bed catalyst, washed with a Wasohmedium at least 6 hours at a temperature of less than 40 ⁰ O. The tafaschmedium consists essentially of about 90 % water and less than 10 % polycarboxylic acid such as citric acid and / or succinic acid. To further increase the activity, subsequent to the wash, a treatment with 0.1 to 10% aqueous alkali hydroxide solution at less than 50

be connected. Finally, processes for activating, reactivating and selecting catalysts which have lost their activity or selectivity by carbon or hydrocarbon deposits (DD-PS 142 270, DE-AS 2 326 072, DE-AS 2 327 209, DE -OS 2 459 879, DE-OS 2 633 995, DE-OS 2 636 217, DE-OS 2 711 209, DE-OS

2 832 808, DE-OS 2 950 305, DE-OS 3 006 615, DE-OS

3,124,647, DE-OS 3,204,954).

These processes all have a targeted treatment of the catalysts to the content, with the introduction of Sr ".erstoff and possibly other reactive substances, a reaction, combustion or burning of the above deposits with simultaneous production of, for example, CO and / or C0p- (ias in various technical facilities, such as combustion chambers, fluidized bed apparatus, etc. takes place After an inert gas purging and ansohliessender reduction in V / generstoffstrom example, the catalyst is operational again.

A disadvantage of all processes is that they require any additives and basically require a catalyst change and thus a longer production interruption. Also, the technical effort to carry out the process is very expensive either by thermal treatment and / or many process steps.

Object of the invention

The aim of the invention is to use the catalyst used in the suspension hydrogenation of butynediol-1,4, which has suffered a loss of time,

to increase its activity by simple measures, so that the loss of time largely ϊ, ό. compensate and thus avoid a catalyst reactivation associated with a Katalysaüorwechsel.

Explanation of the essence of the invention

The technical task

The object of the invention is to develop a process for increasing the activity of the catalyst used in the suspension hydrogenation of jutindiol-1,4, which satisfies the above objective.

Features of the invention

According to the invention the object is achieved by largely suppressed by hydrogen pressure reduction for a certain time, the actual hydrogenation and then continues after recovery of the hydrogen pressure required for the hydrogenation of the hydrogenation process.

It has been found that by this procedure, a catalyst reduced in activity undergoes a strong increase in activity when the pressure reduction is maintained at 0.1 to 0.5 IvIPa, preferably 0.1 MPa, for at least ¹ 60 s.

In addition to the discontinuous operation of this operation to increase the activity of the hydrogenation catalyst, this process can also be used continuously by removing a catalyst-containing oil stream from the hydrogenation reaction system while lowering the hydrogen pressure for one uestiiunite time and then returning it to the reaction system.

Execution example

The invention will be explained below using an exemplary embodiment:

The continuous suspension hydrogenation of aqueous butynediol-1,4-solution was carried out in the presence of a nickel-containing catalyst supported on SiO 2 in a 2-1 reactor at a temperature of 353 K and a pressure of 1.5 MPa at a flow rate of 1 l / h performed. The concentration of the supplied aqueous Brtindiol-1,4-solution was 1.44 mol / 1 Butindiol. The reactor contained 3.3 g of catalyst. After 50 h, the catalyst suffered a loss of activity by 37 %. After this reaction time, the supply of hydrogen was discontinued and the reactor was expanded from 1.5 MPa to 0.1 MPa and maintained at this pressure for 300 seconds. After restoring. ; the o. g, operating parameters required for the hydrogenation reaction, the hydrogenation could be continued with the same catalyst, with its activity had almost reached the initial value again.

Claims (2)

Erfindungsanspruoh 1. A Process for Increasing the Catalyst Activity in Butynediol-1,4-Hydrogenation of the Supported Base Aluminum oxide and / or silicon dioxide in the suspension hydrogenation of butynediol-1,4 to 1,4-butenediol and / or 1,4-butanediol in the pressure range 0, 5 to 4 MPa nickel catalyst or niokelhaltigen mixed catalyst, which has already suffered a prolonged use loss of activity, characterized in that by depressurization to 0.1 to 0.5 MPa for a period before. at least 60 s, the actual hydrogenation process largely suppressed and then continued by restoring the pressure required for the hydrogenation of the hydrogenation process. 2. The method according to item 1, characterized in that continuously withdrawn a catalyst-containing partial stream of the reaction system under pressure reduction and then fed to the Reekfcionssystem again.