GB1113326A - Reducing fouling in refining of petroleum products - Google Patents

Abstract

In a process wherein a hydrocarbon stock, e.g. naphthas, gas oils, crudes, gasoline and kerosine is heated by direct contact with a heat exchange surface having a temperature of 100 DEG to 2000 DEG F., fouling of the surface is inhibited by incorporating in said stock an N-alkyl amidophosphoric acid or salt selected from: <FORM:1113326/C4-C5/1> <FORM:1113326/C4-C5/2> <FORM:1113326/C4-C5/3> <FORM:1113326/C4-C5/4> <FORM:1113326/C4-C5/5> <FORM:1113326/C4-C5/6> <FORM:1113326/C4-C5/7> and mixtures thereof where R1, R2, R3, R4, R5 and R6 are hydrogen, alkyl, alkenyl, alkaryl, aryl; cycloaliphatic, cycloheteryl or the foregoing radicals containing substituents, with the proviso that at least one of the radicals contains at least 8 C.ALSO:In a process wherein a hydrocarbon stock is heated by direct contact with a heat exchange surface having a temperature of 100 DEG F. to 2000 DEG F., fouling of the surface is inhibited by incorporating in said stock an N-alkyl amidophosphoric acid or salt selected from: <FORM:1113326/C6-C7/1> <FORM:1113326/C6-C7/2> <FORM:1113326/C6-C7/3> <FORM:1113326/C6-C7/4> <FORM:1113326/C6-C7/5> <FORM:1113326/C6-C7/6> <FORM:1113326/C6-C7/7> and mixtures thereof where R1, R2, R3, R4, R5 and R6 are hydrogen, alkyl, alkenyl, alkaryl, aryl, cycloaliphatic, cycloheteryl or the foregoing radicals containing substituents, with the proviso that at least one of the radicals contains at least 8C.ALSO:N-Substituted amido-phosphoric acids and salts, esters or ester-salts thereof used to prevent corrosion are obtained by the reaction of an acidic phosphorus compound, e.g. P2O5, with a primary or secondary amine (including an N-aliphatic imidazoline) containing at least one radical having at least 8 carbon atoms which may be followed by reaction with an alcohol and/or neutralization with an amine. In an example, mixtures of compounds of the formulae <FORM:1113326/C2/1> <FORM:1113326/C2/2> <FORM:1113326/C2/3> wherein the R1 radical is H and the radica R2 is primarily: <FORM:1113326/C2/4> and R6 is isooctyl are obtained by suspending P2O5 in kerosene, adding a commercial tertiary alkyl primary amine mixture (C11-C14) containing the R2 radical, stirring at 100 DEG C., cooling and then adding isooctanol at 40-50 DEG C. A mixture including amine salts is formed by partial or complete neutralization of the above product by using the same amine mixture as neutralizing agent. The neutralizing amine may also be a simple low molecular weight amine and various primary, secondary and tertiary amines and heterocyclic bases are specified for use. A compound of the following formula <FORM:1113326/C2/5> wherein R1 to R5 are radicals derived from the amine is formed by reacting P4O10 and a tertiary-alky primary amine mixture of the above type. In a further example a higher alkyl substituted N-hydroxyethyl imidazoline is used in the first example instead of the tertiary-alkyl primary amine. Several other primary or secondary amines containing a radical having at least 8 carbon atoms which may be used are specified. Also, low molecular weight alcohols can be used and other phosphorus-containing compounds may be used instead of the pentoxide, e.g. phosphoric acid, POCl3, or phosphorous anhydride.