Patent EA-003895-B1 (EA)
Title: Treatment of crude oils
Inventor: GOMEZ RODOLFO ANTONIO
IPC: C10G32/02
Filed: 2000-11-13
Abstract: 1. A process to extract and recover heavy metals and sulfur from crude oil or petroleum fuel products consisting of the steps of: emulsifying the crude oil with an emulsifying agent; adding a leach solution of an inorganic acid to the emulsified crude oil and leaching the emulsified crude oil at elevated temperature and pressure to give a leached emulsified crude oil and a leachate ; separating the leached emulsified crude oil and the leachate, removing a proportion of the leachate and recovering sulfur and heavy metals therefrom; washing the leached emulsified crude oil with water; separating the leached emulsified crude oil and the washing water. 2. A process as in claim 1 where the acid leached and washed crude oil or petroleum product is further leached with an alkali solution while being irradiated with microwaves to remove more sulfur from the crude oil. 3. A process as in claim 1 further including the step of microwave hydrodesulfurizing the leached and washed crude oil using hydrogen gas at a temperature below 220 degree C to ensure there is no quality degradation in the crude feed to produce adesulfurised crude oil and a hydrogen sulphide by-product; and recovering sulfur from the hydrogen sulphide by-product. 4. A process as in claim 1 wherein viscosity of the feedstock crude oil is reduced by addition of a solvent before emulsification and the solvent is recovered for reuse by distillation before treatment. 5. A process as in claim 1 where up to 0.5 % by weight of emulsifying agents is mixed with the crude oil or petroleum product before the process of leaching. 6. A process as in claim 1 wherein the leaching stage is carried out at temperatures of between 25C to 160 degree C and pressure up to 10 Mpa (100 bars). 7 A process as in claim 1 wherein the leaching step is carried out by the application of conventional heat or microwave energy. 8. A process as in claim 1 wherein the leaching step consists of one or more stages with a liquid separation between stages and wherein the leaching step is arranged in counter-current mode. 9. A process as in claim 1 wherein the leach solution contains an inorganic acid and includes a small amount of oxidising agent such as hydrogen peroxide. 10. A process as in claim 1 wherein the step of the recovering heavy metal includes the steps of: separating a bleed solution from the main leaching stream after the anode cell, adjusting the pH of the bleed solution to about between 1.5 and 2.5 using calcium or sodium hydroxide or carbonate, applying hydrogen sulphide gas to the solution to precipitate base metals and other metals susceptible to this treatment and filtering the precipitate, adjusting the pH of the boiling solution to a pH of about between 3.0 to 3.5 using soda ash to precipitate iron oxide which is filtered from the solution, applying a small amount of an oxidising agent such as hydrogen peroxide to convert vanadium ions to their highest oxidation state before applying soda ash or ammonia to the solution to increase the pH to about 3.6 to 4.6, applying hydrogen sulphide gas to the solution to precipitate vanadium sulphide, filtering the vanadium sulphide precipitate, adjusting the pH of the hot solution to between 8 and 10 using soda ash or ammonia to precipitate vanadium hydroxide, and subjecting the waste solution to a vacuum to recover any hydrogen sulphide gas left in the waste solution before the solution is discarded. 11 A process as in claim 3 wherein the hydro-desulfurizing is carried out with the aid of catalysts being cobalt and molybdenum on alumina. 12. A process as in claim 1 wherein the leaching step comprises the steps of: leaching the emulsified crude oil with an acid leach solution, washing the acid leached emulsified crude oil with water, separating the crude oil from the wash water, re-emulsifying the crude oil, leaching the re-emulsified crude oil with analkali leach solution, washing the alkali leached re-emulsified crude oil with water, and separating the crude oil from the wash water. 13 A process as in claim 12 wherein the acid and alkali leached crude oil is subsequently treated in a microwave hydro-desulfurizing step. 14. A process and apparatus to extract and recover heavy metals and sulfur from crude oil or petroleum fuel products consisting of the steps of: making the crude oil readily broken into very small particles by applying solvents and emulsifiers so that there is possible an intimate contact between the crude oil and the leaching solution during leaching, using an apparatus capable of withstanding corrosive conditions, temperature of up to 160 degree C and high pressure up to 10 Mpa (100 bars) and fitted with a stand-pipe, impeller, and baffles to break-up the crude oil into very small particles and intimately mix the crude oil particles and a leaching solution, utilising an apparatus capable of supplying conventional heating as well as applying microwaves at 800 to 22,000 megahertz frequency to the crude oil leach solution mixture to achieve the desired reaction temperature, a leaching step which consists of one or more stages with a liquid separator between stages arranged in counter-current mode, wherein the leach solution contains only an inorganic acid or alkali, or include a small amount of oxidising agent such as hydrogen peroxide, a washing step on the leach crude oil which consists of one or more washing stages with liquid separators between stages arranged in counter-current mode where the wash water is supplied with some alkali if required to ensure the leached and washed crude oil is ideal feed for microwave hydro-treating or refining, the leached and washed crude oil if it contains sulfur above the desired level, is subjected to microwave hydro-treating using hydrogen gas and conventional heating and microwave activation, and the hydro-treating is carried out at high pressure and at a temperature below 220 degree C. 15. A process as in claim 14 wherein the leaching step includes anode cells in the circuit to oxidise suitable ions such as ferrous (II) and vanadium ions before the leach solution is re-applied in the leaching step. 16. A process as in claim 14 further including a metals recovery step first consisting of separating a bleed solution from the main leaching stream after the anode cell, which metal recovery step includes the steps of; separating a bleed solution from the main leaching stream after the anode cell, adjusting the pH of the bleed solution to about between 1.5 and 2.5 using calcium or sodium hydroxide or carbonate, applying hydrogen sulphide gas to the solution to precipitate base metals and other metals susceptible to this treatment and filtering the precipitate, adjusting the pH of the boiling solution to a pH of about between 3.0 to 3.5 using soda ash to precipitate iron oxide which is filtered from the solution, applying a small amount of an oxidising agent such as hydrogen peroxide to convert vanadium ions to their highest oxidation state before applying soda ash or ammonia to the solution to increase the pH to about 3.6 to 4.6, applying hydrogen sulphide gas to the solution to precipitate vanadium sulphide, filtering the vanadium sulphide precipitate, adjusting the pH of the hot solution to between 8 and 10 using soda ash or ammonia to precipitate vanadium hydroxide, and subjecting the waste solution to a vacuum to recover any hydrogen sulphide gas left in the waste solution before the solution is discarded.