Production of unsaturated carboxylic acids or acid esters with a haloapatite-based catalyst
AssigneesEcole Centrale De Lille, Universite De Lille, Centre National De La Recherche Scientifique
InventorsSébastien Paul, Benjamin Katryniok, Franck Dumeignil, Thomas Bonnotte
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Abstract
The present invention relates to the use of haloapatites as catalysts of the dehydration reaction of α-hydroxylated carboxylic acids or acid esters, in particular of lactic acid or of methyl lactate, and also to a process for producing unsaturated carboxylic acids or acid esters, in particular acrylic acid or methyl acrylate, in the gas phase in a stainless steel reactor, in the presence of such a catalyst.
Claims10
Process for producing an unsaturated carboxylic acid or an unsaturated carboxylic acid ester in the presence of a catalyst, said process comprising the steps of:
- dehydrating an α-hydroxylated carboxylic acid or an α-hydroxylated carboxylic acid ester, respectively, said step being carried out in the gas phase, in the presence of a solid catalyst containing at least one halogenated apatite of formula (I) below:
- Ca10-x[(PO4)6−(x+y+z)(HPO4)x+z(CO3)3][Y2−(x+y+z)(CO3)y+z] (I)
- in which:
- Y represents at least one anion selected from the F−, Cl− anions, and the combinations of at least one F− or Cl− anion with an OH− anion;
- 0≤x≤1;
- 0≤y≤1;
- 0≤z≤1;
- 0≤x+y+z≤1,
- said process being carried out in a stainless steel reactor.
Dependencies are inferred from the claim text.