| 摘要 |
A process for the production of glycolic acid (hydroxyacetic acid) from formaldehyde comprising reacting formaldehyde with carbon monoxide and water in the presence of a silica catalyst, wherein from about 200 to about 5000 ppm, preferably 300-500 ppm of an alkyl silyl sulfonic acid, preferably a trihydroxysilylalkyl sulfonic acid is supplied to the reaction. The preferred acids are trihydroxysilylpropyl sulfonic acid and trihydroxysilylethyl sulfonic acid. The silica catalyst may be porous or non-porous and may be functionalised e.g. by the presence of acid groups tethered to the silica support. The alkyl silyl sulfonic acid may be supplied in a recycle product stream. The reaction may be carried out using a solvent including water, propionic acid and 2,3,4,5-tetrahydrothiophene-1,1-dioxide. The reaction is preferably conducted at 100-250 ºC and 10-200 bara (0.1-20 MPa). |
