Systems for modifying desalter alkalinity capacity and uses thereof

A system comprising:

• a desalting vessel;
• a pretreated hydrocarbon feedstock supply operable to flow the pretreated hydrocarbon feedstock into the desalting vessel, wherein the pretreated hydrocarbon feedstock supply comprises at least hydrocarbon feedstock and dissolved salts;
• a wash water supply operable to flow the wash water into the desalting vessel, wherein the wash water supply comprises at least water;
• an alkalinity modifier supply operable to flow the alkaline modifier into the desalting vessel, wherein the alkalinity modifier supply comprises at least one alkalinity modifier or solutions thereof;
• a desalted crude outlet operable to flow desalted crude oil out of the desalting vessel, wherein the desalted crude oil comprises hydrocarbon feedstock with less dissolved salts by weight than the hydrocarbon feedstock in the pretreated hydrocarbon feedstock supply;
• and
• a wash water brine outlet operable to flow brine out of the desalting vessel, wherein the brine comprises water with more dissolved salts by weight than the water in the wash water supply, wherein the system is operable to maintain the brine at a pH in the range from 5.5 to 6.5, wherein the alkalinity modifier supply is selected from the group consisting of sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, ammonium bicarbonate, and ammonium carbonate.