Process for the catalytic production of formic acid at an oxygen partial pressure below 1 bar and for the regeneration of catalysts used therein

Abstract

The present invention relates to a method for the catalytic production of formic acid at an oxygen partial pressure below 1 bar and for the regeneration of the catalyst used therein, wherein at a temperature above 70°C and below 120°C, a liquid solution (12) in a vessel (10) In the catalyst, the general formula is [PMo x V y o 40 ] n‑ The polyoxometalate ion is contacted with an α-aldol, an α-hydroxycarboxylic acid, a sugar, a glycoside, or a polymer comprising a carbon chain having at least one repeatedly attached to the carbon chain as a substituent The OH group of the radical and / or the O, N or S atom recurring in the carbon chain, where 6≤x≤11 and 1≤y≤6 and 3<n<10 and x+y=12, where n , x and y are each an integer, wherein in this process the reduced catalyst returns to its original state by oxidation, wherein said contacting takes place at an oxygen partial pressure of less than 1 bar in a vessel (10), wherein, for said catalyst Oxidation, part of the liquid solution (12) is discharged from the container (10), oxygen or a gas mixture containing oxygen is provided at an oxygen partial pressure of 1 to 500 bar, and it is subsequently returned to the remaining liquid solution (12), wherein the partial pressure of oxygen in said vessel is continuously maintained below 1 bar, wherein said portion of liquid solution (12) is applied to The oxygen partial pressure of the liquid solution (12) of 1 to 500 bar is reduced below 5 bar.

Description

technical field [0001] The present invention relates to a method for the catalytic production of formic acid and regeneration of the catalyst used therein. This method is known from EP2473467 B1, where in a vessel at a temperature above 70°C and below 120°C, in liquid solution, the general formula [PMo x V y o 40 ] 5- The polyoxometalate ion is contacted with α-aldol, α-hydroxycarboxylic acid, sugar or glycoside (glycoside), wherein 6<x<11, 1<y<6 and x+y=12, where x and y Each is an integer. The thus reduced catalyst returns to its starting state by oxidation. Background technique [0002] According to EP2473467 B1 it is advantageous if the contacting takes place at an oxygen partial pressure of 1 to 500 bar. The higher the partial pressure of oxygen, the faster the oxidation of the catalyst that becomes less in the process. However, it has been found that the pressure vessels made of steel used to perform this process suffer from severe corrosion. To avo...

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Problems solved by technology

Implementing this process becomes relatively expensive if the vessel is made of this alloy

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