Abstract: The present invention is a method to identify a refinery solid foulant of unknown composition including the following steps: obtaining a solid foulant sample, removing trapped feed from the sample with a solvent to obtain an insoluble sample, scanning the insoluble sample with a scanning electron microscope and energy dispersive x-rays, performing a thermal gravimetric analysis including an ash test on the insoluble sample to determine the presence of polymer, coke and inorganic elements, performing an elemental analysis on the insoluble sample for the elements carbon, hydrogen, sulfur, nitrogen, halogens, and metals, performing an optical microscopy on the insoluble sample to determine the presence of wax, asphaltenes, anisotropic coke and isotropic coke, and identifying the solid foulant.

Abstract: The present invention is an asphaltene dispersant containing an aromatic, a sulfonic acid head, and an alkyl tail containing 16 carbons or more and at least one branch of a methyl or longer alkyl. Preferably, the aromatic is a fused two ring aromatic and the tail is a two, branched alkyl tail of 30 carbons or longer.

Abstract: The present invention includes a process for blending two or more petroleum oils, any component of which may be an unprocessed crude oil or a processed oil derived from petroleum, in a manner to minimize fouling and coking of refinery process equipment. The blending method includes the steps of determining the insolubility number, I, for each oil, determining the solubility blending number, S, for each oil, and combining the petroleum oils in the proportions in order to keep the solubility blending number of the mixture higher than 1.4 times the insolubility number of any oil in the mixture. The present invention also includes selecting petroleum oils to minimize fouling.

Abstract: The present invention includes a method for blending two or more petroleum feedstreams, petroleum process streams, or combination thereof, at least one of which includes the solute asphaltenes so that the asphaltenes remains a solute. The blending method includes the steps of determining the insolubility number, I.sub.N, for each feedstream, determining the solubility blending number, S.sub.BN, for each feedstream, and combining the feedstreams in order of decreasing S.sub.BN number of each feedstream such that the solubility blending number of the mixture is greater than the insolubility number of any component of the mix, when the solubility blending number of any of the feedstreams or streams is equal or less than the insolubility number of any of the streams.