Abstract: The invention comprises a method of inhibiting naphthenic acid corrosion in a high temperature hydrocarbon system, comprising adding to the system a corrosion-inhibiting amount of a phosphate ester and a corrosion-inhibiting amount of organic polysulfide.

Abstract: Disclosed are a method for inhibiting corrosion in crude oil distillation towers, an improvement in crude oil fractionation, a method for dispersing iron sulfide in a hydrocarbon stream and a hydrocarbon dispersion using the reaction product of hydrocarbyl succinic anhydride and an amine. The reaction product has a molecular weight of from 500-800, the hydrocarbyl substituent has 6-20 carbon atoms, and the amine is selected from EDA, DETA, TETA, TEPA, PEHA, AEP, piperazine, 1,2-PDA, 1,3-PDA, IBPA, MDA or HMDA. The imide product is a filming inhibitor used to treat metal surfaces subject to mineral acid corrosion and disperse iron sulfide particles by adding 3 to 24 ppm to sweet or sour crude contacting the metal surfaces.

Abstract: Corrosion of the metallic surfaces of distillation columns, trays, packing, and pumparound piping used in the production of hydrocarbons can be controlled by adding a neutralized or non-neutralized thio-phosphate or thio-phosphite ester to the hydrocarbon distillate contacting the metallic surfaces.

Abstract: An apparatus of provided for simulating corrosion activity of a high temperature liquid stream. The apparatus includes a canister in which is positioned a plug, occupying part of the internal volume of the canister. A stream of high temperature liquid enters the canister through an inlet, flows around the plug, and exits the canister through an outlet. The volume and configuration of the plug may be varied to simulate corrosion activity under various flow regimes. Probes may be placed in the liquid stream to detect corrosion activity and temperature. Several canisters may be arranged in series, and corrosion activity may be simulated in each canister simultaneously to determine effects of various parameters such as liquid impingement, velocity, and temperature on corrosion activity.

Abstract: Sulfonated alkylphenol is added to crude oil at 5 to 200 ppm to inhibit naphthenic acid corrosion of ferrous metal process piping and equipment in contact with the crude oil at naphthenic acid corrosion conditions. There are disclosed corrosion-inhibited hydrocarbon fluids, an improvement in hot hydrocarbon processing with sulfonated alkylphenol, a method for inhibiting naphthenic acid corrosion therewith, and a method for catalytically processing hydrocarbons with sulfonated alkylphenol to avoid catalyst poisoning by iron compounds.