JPS591430B2 - Method for pyrolyzing and coking heavy hydrocarbon oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to the conversion of hydrocarbonaceous feedstocks collectively referred to in the art as "black oil", and in particular the present invention is applicable to the conversion of heavy hydrocarbonaceous feedstocks to the pyrolysis of heavy hydrocarbonaceous feedstocks. , which is used when producing coke.

What is called black oil includes, for example, atmospheric distillation column residue, vacuum distillation column residue, crude oil residue, coal oil extract, top crude oil, tar sand oil extract, etc. , these can also be treated according to the present invention.

Black oil contains a large amount of high molecular weight sulfur-based compounds and nitrogen-based compounds, as well as significant amounts of hydrocarbon-insoluble asphalt-based compounds and organometallic compounds containing mainly iron, nickel, and vanadium.

Most of these black oils have a specific gravity of about 0.8762 or less, and more than 10% by volume of these black oils have the property of boiling at a temperature of 566° C. or higher, and in recent years, such black oils have been provided in abundance.

This situation has increased the need to convert black oil into low boiling hydrocarbon products and coke, the demand for which is steadily increasing.

An example of the feedstock described above has a specific gravity of 0.8927, contains 0.17% by weight sulfur, and has a total metal content of about 13
The I tile is residual oil.

The main difficulties involved in converting black oil are due to the presence of bituminous materials and organometallic compounds.

Fixed-bed catalytic processes have been used advantageously in many hydrocarbon conversion processes, but when processing liquid oils, they suffer from the rapid deposition of coke on the catalyst and the high metal contamination of the catalyst. It is not suitable because the ounce dream period until picking up the item is extremely short.

Other feedstocks that can be treated by the process of the invention include atmospheric distillation residues, atmospheric and vacuum gas oils, coker cass oils, fluidized cracker slurry oils, furfural extracts, high temperature cracking residues, and specialty cokes. Other feedstocks suitable for the production of coke include intermediate coke (derived from asphaltones and distillable heavy hydrocarbons) and needle coke (derived from highly aromatic cool or distillable hydrocarbons). The amount of coke derived from asphalt is 15% or less).

The primary purpose of this invention is to convert hydrocarbon feedstocks to produce gasoline and specialty coke.

Accordingly, the present invention provides a method for thermally decomposing and coking heavy hydrocarbon oil containing a high molecular weight sulfur compound and a nitrogen compound, and further containing a hydrocarbon-insoluble asphalt compound and an organometallic compound. (a) The above-mentioned heavy hydrocarbon oil is introduced into a fractionating column at an intermediate point in terms of height, and from the fractionating column, a gasoline stream as an overhead component and an intermediate heavy hydrocarbon oil are introduced. removing the heavy fraction stream and the bottoms stream; (b) passing it through the first pyrolysis coil under an elevated pressure in the range of 18 to 35 atmospheres (absolute) while passing the intermediate heavy fraction stream to 482 to 566 atmospheres (absolute); (c) directing the heated heavy distillate stream from a first pyrolysis coil to a cracking reaction chamber; (d) subjecting said bottoms stream to a pressure within the range of 2 to 7.8 atmospheres (absolute); (e) directing the heated bottoms stream from the second pyrolysis coil to a coke room where it is coked; Let the product accumulate.

(f) Remove the remaining effluent vapor from the coke chamber and mix it with the reaction chamber effluent, and the resulting mixture is added to the aforementioned portion below the point of introduction of the heavy hydrocarbon oil. (g) recovering gasoline and coke products;

Other embodiments of the invention, which relate to preferred product distributions and operating conditions, will be readily apparent to those skilled in the art from the following description, as well as other objects of the invention. I can do it.

In order to be competitive with modern hydrocarbon processing technologies, the pyrolysis unit and coker combination must be utilized in increasingly advanced ways without compromising its fundamental and proven advantages. Must be.

As energy sources become more scarce, their cost must become more and more expensive, so it is necessary to utilize all energy sources and to improve their utilization as much as possible.

As black oil and other heavy fractions are less desirable in crude oil, their utilization is becoming increasingly important.

Although pyrolysis units and cokers have been commonly used in the past to convert black oil, only recently have they
Producing the maximum amount of gasoline with special coke is
It is strongly requested.

The inventor has discovered that without overloading the coke chamber with steam,
An improved method of converting black oil into gas, gasoline and special coke has been discovered.

The method of the present invention is to send the reaction chamber effluent directly to the fractionation column without passing it through the coke room.

The tar present in this reaction chamber effluent is recycled with fresh feed through the fractionator to the second pyrolysis coil (A coil) and then to the coke room where it contributes to the production of total coke.

The light gas oil in the reaction chamber effluent and the light gas oil produced in the A coil after fractionation are recycled to the first pyrolysis coil (B coil).

The gas and gasoline are then removed from the fractionator as overhead components.

This mode of operation maintains the mixed feed required for total conversion at moderate vapor rates (in the coke room).

Additionally, the present invention allows the use of small diameter and/or low pressure coke chambers.

The operating conditions for the first pyrolysis coil, namely the B coil, include:
Temperature of approximately 487-566℃ and approximately 18-35 atmospheres (absolute)
pressures are usually included.

The operating conditions for the second pyrolysis coil, namely the A coil, include:
Temperatures of about 468-510°C and pressures of about 2-7.8 atmospheres are typically included.

Note that the above coil pressure means the pressure at the outlet of the coil.

Hereinafter, the present invention will be described with reference to the accompanying drawings, but the accompanying drawings are merely presented for convenience of explanation.

Therefore, various ancillary equipment such as valves, controls, equipment, pumps, heat exchangers, start-up lines, heat recovery circuits, etc. have been removed from the drawings.

However, the use of these conventional hardware will be obvious to those skilled in the petroleum refining and processing arts.

In the figure, the feedstock, black oil, is introduced into the fractionator 2 through line 1 after heat exchange with the hot effluent (this part is not shown).

Fractionation column 2 is maintained at a temperature and pressure such that line 3 provides a gasoline stream, line 4 provides a heavy distillate stream, and column 5 provides a black oil stream.

The heavy distillate stream is introduced via line 4 into B coil 6, which is maintained at a maximum temperature of approximately 527°C.

The effluent from B coil 6 is sent via line 7 to reaction chamber 8.

The reaction chamber 8 is maintained at a pressure of approximately 23 atmospheres (absolute).

The effluent from reaction chamber 8 is introduced into fractionating column 2 via line 9.

The flank oil stream is introduced via line 5 into the A coil 10, which is maintained at a maximum temperature of approximately 510°C.

The effluent from A coil 10 is sent via line 11 to coke chamber 12.

The coke chamber 12 is maintained at a zero pressure of about 42 atmospheres (absolute).

Effluent from coke chamber 12 is introduced into fractionator 2 via lines 13 and 9.

The following examples are illustrative of the invention and are not intended to unduly limit the scope of the invention.

Example: An atmospheric distillation residual oil having a specific gravity of 0.8927, a sulfur content of 0.17 wt%, and a total metal content of i 3 ppm was processed at 2,225 m per day using a conventional thermal cracker and a coker. .

The product was recovered and the coke room effluent distribution is shown in column A of Table 2.

Next, the same volume of the above-mentioned atmospheric distillation residue per day was treated according to the treatment pattern shown in the attached drawings.

In this case, the mixed feed in the A coil was operated at 2 and the total mixed feed was operated at 4.8.

The product was then recovered and the cokebox effluent distribution is shown in column B of Table I.

As can be seen from Table 1, by employing the method of the invention, the effluent from the coke room is significantly reduced and the invention therefore allows for economical operation.

The foregoing description clearly demonstrates the improvements achieved by the present invention as well as the advantages of implementing the process for producing gasoline and specialty coke from hydrocarbon oils.

[Brief explanation of the drawing]

The drawing is a flow diagram illustrating one embodiment of the invention. 2...Fraction column, 6...First pyrolysis coil (B coil), 8...Reaction chamber, 10...
...Second pyrolysis coil/l/(A coil), 12...
...Coke room.

Claims (1)

[Claims] 1(a) A heavy hydrocarbon oil containing a high molecular weight sulfur-based compound and a nitrogen-based compound, as well as a hydrocarbon-insoluble asphalt-based compound and an organometallic compound, is collected in a fractionating column. (b) take out from the fractionating column a heavy fraction stream intermediate to the gasoline stream as the overhead component and a column bottom stream;
(c) cracking the heated heavy fraction stream from the first pyrolysis coil while passing it through a first pyrolysis coil under increased pressure in the range of atmospheric pressure (absolute); (d) heating said bottoms stream to a temperature of about 468 to about 510° C. while passing it through a second pyrolysis coil at a pressure in the range of 2 to 7.8 atmospheres (absolute); (e) directing the heated bottoms stream from the second pyrolysis coil to a coke chamber where coke product accumulates; and (f) removing residual effluent vapor from the coke chamber and transferring it to the reaction chamber. (g) recovering gasoline and coke products; A method of pyrolyzing and coking the heavy hydrocarbon oil described above. 2. The method according to claim 1, wherein the heavy hydrocarbon oil as the feedstock has a final boiling point of 566°C or higher. 3. Claim 2 in which at least 10% by volume of the heavy hydrocarbon oil feedstock boils at a temperature of 566°C or higher
The method described in section.