Abstract:
The present invention relates to the use of a polyester which bears hydroxyl groups and is preparable by polycondensation of a polyol containing two primary OH groups and at least one secondary OH group with a dicarboxylic acid or anhydride thereof or ester thereof bearing a C16- to C400-alkyl radical or a C16- to C400-alkenyl radical as an antifoulant in the thermal treatment of liquid hydrocarbon media in the temperature range from 100 to 550 DEG C.