Removal of olefins from hydrothermally upgraded heavy oil

A method for sulfur removal and upgrading, the method comprising the steps of:

• mixing a heated oil feed and a supercritical water feed in a feed mixer to produce a mixed stream, wherein a ratio of the volumetric flow rate of the heated oil feed to the supercritical water feed is such that there is a greater amount of water than oil by volume as measured at standard temperature and pressure (SATP);
• introducing the mixed stream to a supercritical water reactor;
• allowing conversion reactions to occur in the supercritical water reactor to produce a reactor effluent;
• introducing the reactor effluent to a cooling device;
• reducing the temperature of the reactor effluent in the cooling device to produce a cooled fluid;
• introducing the cooled fluid to a depressurizing device;
• reducing the pressure of the cooled fluid in the depressurizing device to produce a discharged fluid;
• introducing the discharged fluid to a gas-liquid separator;
• separating the discharged fluid in the gas-liquid separator to produce a gas phase product and a liquid phase product;
• feeding the liquid phase product to a pump;
• increasing the pressure of liquid phase product to produce pressurized liquid product, wherein the pressure of pressurized liquid product is greater than the critical pressure of water;
• introducing the pressurized liquid product to a hydration reactor, wherein the pressurized liquid product comprises water;
• processing the hydration reactor to produce a hydrated oil stream, wherein the hydrated oil stream comprises water and oxygenates, wherein the hydration reactor is at a temperature between 300 deg C. and 370 deg C. and a pressure of greater than the critical pressure of water such that water is near-critical in the liquid phase;
• introducing the hydrated oil stream to an extraction unit;
• separating the hydrated oil stream to produce an extracted upgraded oil and an oxygenate concentrated stream, wherein the oxygenate concentrated stream comprises the oxygenates and water;
• feeding the extracted upgraded oil to a hydrotreater;
• and
• processing the extracted upgraded oil in the hydrotreater to produce a desulfurized upgraded oil.