Heterogeneous catalysts for transesterification of triglycerides and preparation methods of same

Abstract

This invention belongs to the field of catalysts for the transesterification of triglycerides, for the production of fatty acid glycerin and esters. This invention describes preparatory methods using solid catalysts and the formulation of these catalysts for the production of fatty acid esters, glycerin, and specifically, biodiesel through the heterogeneous transesterification reaction of triglycerides present in vegetable oils and fats, like soy, cotton seed, canola, castor, peanut oils and animal fat. The solid catalysts of this invention are sufficiently magnetic to use in the production of biodiesel from vegetable oils and fats, not only because they work in a similar fashion as state of the art catalysts, but also because of the low cost of the raw materials used in its production. The invention even describes the composition obtained by using the catalysts, in which the purity of the products, such as biodiesel and glycerin is greater than 96.5%.

1 . Heterogeneous catalysts for a process of transesterification of fatty acid esters, characterized by having at least one water-insoluble solid mixed or not into a solid substrate. 
   
   
       2 . Heterogeneous catalysts in accordance with  claim 1 , characterized by said solid being barium oxide and water-insoluble. 
   
   
       3 . Heterogeneous catalysts in accordance with  claim 1 , characterized by said solid being water-insoluble and an apatite which is natural or synthetic, in the form of an oxide or a hydroxyapatite. 
   
   
       4 . Heterogeneous catalysts in accordance with  claim 1 , characterized by said solid substrate being aluminum oxide (Al 2 O 3 ), or silicon oxide (SiO 2 ), or niobium oxide (Nb 2 O 5 ) or a mixture of these in any proportion. 
   
   
       5 . Heterogeneous catalysts in accordance with  claim 2 , characterized by said barium oxide being mixed with gamma-aluminum. 
   
   
       6 . Preparatory method for solid heterogeneous catalysts that contain barium oxide, for the process of transesterification of fatty acid esters, including the following stages:
 preparation of a mixture of 80% p/p of aluminum oxide and 20% p/p of barium oxide octahydrate;   peptizing a mixture in a 4% p/p acetic acid solution;   drying the mixture at 120° C. for 8 hours; and   heating the mixture at 550° C. for 3 hours.   
   
   
       7 . Preparatory method for solid heterogeneous catalysts that contain barium oxide, for the process of transesterification of fatty acid esters, including the following stages:
 provide a load of apatite;   dry at 120° C. for 16 hours; and   heat at 550° C. for 3 hours.   
   
   
       8 . Preparatory method for solid heterogeneous catalysts which contains apatite in accordance with  claim 7 , wherein said apatite is the natural mineral apatite with an enriched phosphorus level, accomplished by using the traditional treatment for phosphoric acid production. 
   
   
       9 . Preparatory method for solid heterogeneous catalysts that contains apatite in accordance with  claim 7 , wherein said apatite is a mixture of oxides with the following elemental composition, phosphorus, 4.1%; barium, 10.0%; calcium, 6.1%; iron, 9.0%; manganese, 1.3%; aluminum, 11.0%. 
   
   
       10 . Composition obtained by the reaction between a vegetable oil or animal fat and an alcohol, characterized by using an insoluble solid catalyst, in accordance with  claim 1 , which includes: not less than 98% p/p of fatty acid esters and no more than 4,500 ppm of fatty acids. 
   
   
       11 . Composition obtained by the reaction between a vegetable oil or animal fat and an alcohol, in accordance with  claim 10 , in which said alcohol is methanol or ethanol.