| abstract |
The present invention is directed to a continuous process for producing hydrocarbyl aldosides. i.e., alkyl aldosides, from carbohydrates and more particularly mixed alkyl glycosides from starch by direct alcoholysis. A carbohydrate, such as starch, is slurred in an alcohol and passed through a heated, confined zone under pressure and other particular conditions in the presence of an acid catalyst to form a mixed alkyl aldoside. According to a preferred embodiment, the converted carbohydrate/alcohol slurry is rapidly cooled after alcoholysis and before recovery of the alkyl aldoside or aldosides. According to another preferred embodiment at least one alkyl aldoside is separated from the resultant alkyl aldoside mixture and the resultant mother liquor is recycled to carbohydrate/alcohol feed slurry. When using starch as carbohydrate and methanol as alcohol, this embodiment optimizes methyl-alpha-D-ghucopyranoside production. |