This invention relates to the conversion of a light candy refinery to a heavy sour refinery via the up entrance addition of a resid hydrocracker.
BACKGROUND OF THE INVENTION
The following are two ways by which a refiner can produce low-sulphur transport gas. The primary is to process a predominantly light candy crude by way of distillation and reaction processes to supply primarily mild transportation merchandise. A second option is to course of a heavy bitter crude oil that requires considerably extra equipment to improve the heavier fraction known as resid to mild products. This heavy sour upgrading has extra tools requirements to reduce the boiling range of the resid and scale back different crude contaminants akin to corrosive acids, nitrogen and sulfur. The heavy bitter crude costs are discounted as a consequence of their processing issues which may make them economically enticing to refine.
Intensive reserves in the form of 鈥渉eavy crudesexist in a variety of international locations, including Western Canada, Venezuela, Russia, the United States, and elsewhere. These deposits of heavy crudes usually exist in areas that are inaccessible by normal means. Usually, the time period 鈥渉eavy crudesrefers to a hydrocarbon material having an API gravity of less than 25.
Many of the Western Canadian heavy crudes are produced by mixing an even heavier bitumen with an API gravity of roughly 6 to 12 with a diluent to have a blended API gravity of approximately 19 to 25. On this case, the bitumen is the troublesome to process element
It will probably value billions of dollars to retrofit a mild candy refinery to course of heavy sour crude. Virtually each course of unit may require retrofitting resulting from its totally different boiling vary and contaminants. There are considerations that the costs of changing refineries to process heavy bitter crude can be hard to recoup. Long run, the flexibility to use heavy sour crude is a matter that’s expected to confront the refining trade for an extended period of time.
Summary OF THE INVENTION
Moderately than incur the price of extensively retrofitting an present mild candy refinery, now we have invented a novel manner of conditioning the heavy bitter crude at the refinery location to make it acceptable for processing in the prevailing mild sweet refinery gear. Our system doesn’t considerably modify an present sweet refinery. Somewhat, we use a resid hydrocracker to situation bitumens or heavy bitter crudes previous to processing in an existing candy refinery.
Refineries and Resid Hydrocrackers are both recognized processes. This invention makes use of the Resid Hydrocracker in a new and revolutionary technique to extra effectively convert a Light Candy (or moderately heavy/sour) Refinery right into a Heavy Sour Refinery. This process feeds a complete or topped crude (atmospheric or vacuum) right into a resid hydrocracker (e.g. LC-Fining or H-Oil) at the refinery to upgrade the Heavy Sour crude right into a light candy crude prior to feeding it into the prevailing refinery. This course of is conducted on the refinery site, but upstream of the prevailing refinery. The first advantage of this invention is that it creates a crude feedstock that an present mild candy refinery can process with out vital modifications. This benefit contains sulfur reduction, nitrogen reduction, removal or corrosive acids and the upgrading of the resid. More particular benefits of this processing scheme embrace that it considerably reduces the prevailing refinery’s hydrotreater revamp work, it eliminates the fractionation tools within the resid Hydrocracker and it efficiently makes use of any present bottoms upgrading tools (e.g. coker, gasification, SDA, and so forth.)
Other objects and advantages of the present invention will turn out to be apparent to these skilled in the art upon a evaluate of the next detailed description of the popular embodiments and the accompanying drawings.
Temporary DESCRIPTION OF THE DRAWINGS
The Determine is a block diagram instance of this invention with a resid hydrocracker upstream of a typical present mild candy refinery.
DETAILED DESCRIPTION OF THE INVENTION
This invention is a hydrotreating course of and apparatus for upgrading an present refinery to course of a heavy hydrocarbonaceous feedstock of heavy oil or heavy bitumen. The method includes the steps of providing a heavy hydrocarbonaceous feedstock, and feeding the heavy hydrocarbonaceous feedstock to a Resid Hydrocracker. The recovered hydrocarbonaceous feedstock has a boiling level which is decrease than the boiling point of the heavy hydrocarbonaceous feedstock and accommodates diminished ranges of sulfur, nitrogen and corrosive natural acids. The recovered lowered boiling level hydrocarbonaceous feedstock then is fed from the Resid Hydrocracking unit to an current refinery. The heavy hydrocarbonaceous feedstock usually is a heavy sour crude or bitumen.
The Figure is a block diagram of a resid hydrocracker based on this invention in combination with a typical existing candy refinery. Heavy sour crude is fed to a resid hydrocracker unit.
A recovered lowered boiling point hydrocarbonaceous feedstock with less sulfur, nitrogen and corrosive natural acids from the Resid Hydrocracker unit is fed to a primary fractionation tower in an existing refinery.
Throughout resid hydrotreating, resid oil is upgraded with hydrogen and a hydrotreating catalyst to supply more worthwhile lower-boiling liquid merchandise.
Conventional resid hydroprocessing typically embody one or more reactors that comprise a reaction chamber, a port at the underside of the reaction chamber by means of which a heavy oil feedstock and pressurized hydrogen gas are introduced, a port at the highest of the reaction chamber by which recent catalyst is introduced, a recycle cup and conduit in the center of the response chamber, an expanded catalyst zone, an ebullating pump that circulates the reactor liquid down by means of the recycle cup and conduit and up through the expanded catalyst zone, a primary catalyst free zone on the reactor bottom (or plenum), a second catalyst free zone above the expanded catalyst zone, a port at the highest of the reaction chamber by means of which an upgraded feedstock is withdrawn from the second catalyst free zone, and a port at the bottom of the response chamber by way of which spent catalyst is withdrawn. Circulation of the heavy oil feedstock upwards by the expanded catalyst zone maintains the solid supported catalyst in an expanded, or fluidized state. It also helps equalize the temperature of the feedstock throughout the response chamber.
The resid hydrocracker reactor usually operates with a hydrogen partial stress between one thousand and 3000 psig and a temperature between 370 and 470 C. A set-mattress, down-circulate resid hydrotreater reactor may be employed on the decrease vary of those temperatures (about 370 to 425 C.). The heavy oil residence time in the resid hydrocracker reactor is adjusted such that the quantity of hydrogen added to the oil meets or exceeds the requirements of the subsequent hydrogen donor cracking course of step. The residence time is often about 5 to 60 minutes.
The above detailed description of the present invention is given for explanatory functions. Will probably be obvious to these skilled in the art that quite a few changes and modifications may be made with out departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being outlined solely by the appended claims.
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