| abstract |
Fouling in a hydrocarbon refining process is reduced by adding to a crude hydrocarbon for a refining process, an additive combination including:n (A) a polyalkenyl-substituted carboxylic acid or anhydride, and (B) an overbased metal hydrocarbyl-substituted hydroxybenzoate detergent,n nwhere the mass:mass ratio of (A) to (B) is in the range of 10:1 to 1:10, and the treat rate of the additive combination is in the range of 5 to 1000 ppm by mass. |