ABSTRACT
There are many types of dehydration catalysts, usually in the family of oxides such as alumina or silica or mixed oxides such as silica alumina. However, dehydrated calcium or barium sulfate or even dehydrated clays are useful. Aluminum phosphate catalyst is a simple catalyst prepared by impregnating gamma-alumina with 85% phosphoric acid solution so as to attain a level of between 10 and 20% P2O5 on the alumina. Boron phosphate catalyst is made by mixing H3PO4 as an 85% solution with boric acid in sufficient ratio that a 10% excess of P2O5 is present. Aluminum phosphate catalyst and Boron phosphate catalyst are both strongly adsorptive and consequently may, depending on the process in which they are used, be contaminated with toxic materials, so they must be handled with extreme care. The boron and phosphate would both be “slow-release” components, which could be beneficial in fertilizers.
