Acid free tri:acetin prodn. - from crude material by treating with steam and inert gas, useful as plasticiser for methylcellulose

摘要

Prodn. of triacetin (I) of low acid content comprises first treating crude (I) (a) with steam at 3-14 m bar and 100-130 degrees C for 0.5-5 hr.; then (b) with inert gas at 100-130 degrees C and 65-130 m bar for 0.5-5 hr. Pref. inert gases are N2, CO2 and anhydrous combustion gases, and crude (I) has free acetic acid content is not >0.5 wt. %, acid value is not >=5 and water content is not >0.5 wt. %. The process reduces free acetic acid content to 0.002 wt. %. (I) is used mainly as plasticiser for methylcellulose used to make cigarette filters.