METHOD FOR START-UP OF HEAVY OIL FEEDSTOCK HYDROCRACKING UNIT Russian patent published in 2024 - IPC C10G47/26 C10G67/02 

FIELD: chemistry.

SUBSTANCE: invention relates to processing of heavy oil stock. Invention relates to a method for starting up a hydrocracking unit, wherein the method comprises steps of: filling the liquid-phase hydrocracking section with starting material in a mixture with hydrogen, heating the starting material by means of a raw furnace to temperature of 250-270 °C, starting raw material is circulated along the circuit of raw furnace – liquid-phase hydrocracking section – separation section – drainage section – raw furnace, when temperature in said circuit reaches 250-270 °C, temperature at the outlet of the raw furnace is raised to 380-385 °C, while circulating along said circuit, while providing removal of the gaseous mixture of hydrocarbons formed in the separation section into the gas-phase hydrocracking section. Gas-phase hydrocracking feedstock is mixed with hydrogen and heated by means of a starting furnace to 220-250 °C, heated raw material of gas-phase hydrocracking is mixed with said gaseous mixture of hydrocarbons and supplied to at least one reactor of gas-phase hydrocracking, with withdrawal of output flow from said at least one reactor of gas-phase hydrocracking through column of fractionation into tank of raw material of gas-phase hydrocracking, reducing temperature difference at starting furnace. Using the starting furnace and heat from said gaseous mixture of hydrocarbons, the temperature of the stream entering at least one gas-phase hydrocracking reactor is increased to 310-320 °C at a rate of not more than 10 °C/h, wherein due to exothermic reaction taking place in said at least one gas-phase hydrocracking reactor, temperature of the output stream from said at least one gas-phase hydrocracking reactor is about 360 °C, wherein said flow passes through a heat exchanger "liquid-phase hydrocracking feedstock – gas-phase hydrocracking output stream", acting as a heat carrier for a liquid-phase hydrocracking feedstock flow, providing a temperature difference between the flow entering the raw furnace and the flow leaving the raw furnace in range of 45 to 115 °C. Liquid-phase hydrocracking feedstock is used to replace the starting feedstock. When the conversion of the main raw material reaches about 50-60%, heating of the gas-phase hydrocracking raw material using the starting furnace is excluded.

EFFECT: increasing the speed, safety and reliability of the hydrocracking unit start-up phase, as well as ensuring the stability of further operation of the unit.

12 cl, 1 dwg, 1 ex