JPS58108293A - Conversion of hydrocarbon fraction - Google Patents

Abstract

PURPOSE:To effect highly efficient conversion to fuel (oil) components, fuel raw materials, materials for petrochemical industry and intermediates, by the hydrogenation under a specific cpnditions, in the presence of a hydrogen-contg. gas and catalyst(s), of a hydrocarbon fraction being partly or complately in liquid state. CONSTITUTION:A hydrocarbon fraction 1 is divided into the same number (>=2) of fraction flows as that of the passing tube of a heating oven F, while a hydrogen-contg. gas 2 is also divided into the same number of fractional flows as the above at <=520 deg.K under a hydrogen partial pressure >=0.7MPa. Said fractional flows are each mixed followed by elevating to the reaction temperature by the heating oven F, etc. to carry out a reaction in a reactor G. The resulting reaction product flows are cooled to a point <=410 deg.K through a counter-current heat exchange with the above mixed fractional flows PHInd the raw material w sigma r &/llowed by separating unreacted matand the raw material flows followed by separating unreacted material flows and then carrying out a refining or decomposition through a hydrogenation reaction in the presence of a hydrogen-contg. gas and at least one sort of catalyst. EFFECT:Capable of reducing the amount of the circulating gas to a minimum, preventing the local overheat of the heating oven and pressure loss, thus leading to longer catalyst life.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a process in which a hydrocarbon fraction in a partially or completely liquid state is treated in the presence of a hydrogen-containing gas and one or more catalysts.
It relates to methods of conversion into fuel oil components, fuel components, raw materials for fuel production, or raw materials and intermediate products for the petrochemical industry.

The method of the present invention is used in a hydrorefining process and/or a hydrocracking process for hydrocarbon fractions.

It is known that catalytic hydrorefining and/or catalytic hydrocracking convert petroleum fractions into fuel components, fuel oil components, raw materials for fuel production or raw materials and intermediate products for the petrochemical industry. ing.

Chemical engineering progress volume 81 188
5th year lO month p? ? -82, Volume 83, August 1887, Oil and Gas Journal 1111.5.1
969 p131-139, 1B, 5. 197
7 years p1413-185, Journal of the Japan Petroleum Institute Vol. 13 No. 1, 1
May 871, Hydrocarbon Processing 5
Vol. 1, No. 9, August 1872, p. 154-164, Vol. 53, No. 9, March 1874, ptao -151, Vol. 58, p. 10
Issue October 1978, p13? -142, U.S. Patent 3
41573? , 3θ[112, 31391051
1. 38910B? , German Publication No. 233038
The hydrogenation refining process known by et al. 5 uses as reaction conditions a pressure between 1-2 ONPa, a temperature between 550-720 degrees, and a recycled gas to product ratio of 100-
It needs to be between 2000m3iN/m3.

US Patent 38209B2, Oil and Gas Journal 20.3.1θ67 PL70, 31.
5.197ip70-73, Hydrocarbon Processing Vol. 51 No. 9 August 1872 p139-14
6, Vol. 53, No. 9, September 1974, p12B-13
2, Vol. 57, No. 5, May 1978, pH 7-121, the known hydrogenolysis method uses a pressure between 5-25 NPa in the reaction zone, 58 G-730
Operating at temperatures between 500 and 500 degrees.

Matsuf Grow Hill Petroleum Processing
According to p5-18 of the 1887 edition of the Handbook, the cost-effective use of carbon steel is based on hydrogen partial pressure of 0.7 MPa.
The above configuration is effective only in a low temperature range.

Particularly in the temperature range above 470°C, depending on the partial pressure of hydrogen sulfide and hydrogen, the use of expensive high-alloy steels in hydrorefining or hydrocracking plants is essential and therefore These plants for decomposition processes necessarily consist to a large extent of high-alloy steel.

The raw material to be converted and the hydrogen-containing gas are heated to the desired or required temperature, generally by heating in a furnace in which the gas or fuel oil is combusted and by heat exchange with the reaction products. Ru.

The utilization of the heat content of the reaction products for the heating of the raw materials to be converted and of the hydrogen-containing gas is applied in order to reduce the energy consumption as much as possible, so that the reactants are often It is heated only by heat exchange to a temperature slightly lower than the above temperature.

However, a separate furnace is required in any case to adjust the required reaction temperature.

As is known, the separation of the reaction products is carried out stepwise in high-temperature and low-temperature separators, with
According to East German Economic Patent No. 148887, it is preferable to wash the recycled gas with the condensate or part of the corresponding cryogenic separator.

As shown in FIG. 1, the desired separation conditions are usually adjusted in part by injecting a heat exchanger.

This bypass control has the disadvantage that it has a relatively low temperature and a relatively high temperature hydrogen partial pressure car of 0.7 MPa.
The above products combine under critical conditions due to the selection of plant constituent materials and the resulting cost.
Therefore, expensive solutions and/or higher temperature designs must be adopted, as material stability problems may arise.

In a typical plant with an annual crude raw material consumption of 501,300,000 yen, even if the heat exchange amount requires multiple heat exchangers in series, the amount of heat exchanged between the population of two reactors and the mixture of The heat exchange is a single flow path.

However, due to pressure loss limitations and especially due to the maximum permissible heating tube diameter, in all plans (4) the heating furnace has at least two or more flow passages.

The limits on the tube diameter of the furnace tube bank are determined for process and cost reasons and technical feasibility, especially by the maximum permissible heat transfer surface load,
S factors such as the maximum allowable internal temperature of the tube and the maximum allowable temperature gradient at the midpoint between the cross section of the tube and H.

Therefore, it occurs.

Used in hydrogen refining method or hydrogen cracking method 1. Since the petroleum fraction, which is heated in the furnace, is only partially or almost evaporated under the reaction conditions, the mixture of hydrogen and hydrocarbons to be heated in the furnace is a two-phase mixture. It is.

As a result, in the practical operation of such furnaces, a homogeneous distribution of the gas-liquid mixture into the individual passage lines in the furnace cannot be achieved, and this phenomenon is limited to the minimum amount of hydrogen-containing recycle gas. This is of particular importance when a system is used, which is a desirable goal for energy reasons, but the non-uniform feeding of the through lines leads to local overheating, undesired decomposition and condensation reactions. , coking and final production, leading to blockage of the respective pipe banks and the operation having to be discontinued.

Hydrocarbon mixtures also tend to increase coke formation in the downstream reaction zone and deposit on the catalyst, causing increased pressure drop in the reactor and loss of catalyst activity.

Hydrocarbon Processing, Vol. 58, No. 5, May 1979, since a uniform supply of a gas-liquid mixture to the furnace within a favorable pressure and temperature range is not possible with currently available means of flow control. As noted elsewhere, separate heating of the hydrogen-containing gas and the partially or fully liquid petroleum fraction in separate and separate furnaces may be employed in some cases. ing.

However, this technique is more costly and requires more energy due to the use of two furnaces.

Heating petroleum fractions to temperatures above 600 degrees in the absence of hydrogen risks undesired cracking and coking. In addition, this technique cannot meet the demands for energy saving and low cost solutions for controlling the conditions of reaction product separation.

The object of the invention is to convert a hydrocarbon fraction in a partially or completely liquid state into a fuel oil in the presence of a hydrogen-containing gas and one or more catalysts in a large-scale hydrorefining and/or hydrocracking process. Improved technical properties and economics for conversion into useful products such as components, fuel components, raw materials for fuel production or raw materials and intermediate products for the petrochemical industry.

The object is to provide an effective method with increased reliability and flexibility.

The purpose of this conversion process is to make it more efficient and reliable in operation through technical improvements in hydrorefining and/or hydrocracking processes.

According to the present invention, a partially or completely liquid raw material consisting of woody hydrocarbons is divided by flow control into at least two or more branch streams, the number of which is equal to the number of pipes passing through the heating furnace upstream of the reactor. , the hydrogen-containing gas also has a hydrogen partial pressure of 0.7 MPa.
Above, at a temperature of 520 degrees or less, the gas is divided into the same number of substreams by flow control as the substream, and each of the gas substreams is mixed with the corresponding raw material substream to form a mixed substream group, and each of the mixed substreams is used for one reaction. The temperature is raised to a predetermined reaction temperature by countercurrent heat exchange with the reaction product coming out of the reactor and subsequent heating by a heating furnace in a multi-pass pipe, and then the heated mixed stream is led to a reactor and reacts. The reaction product stream is finally separated after countercurrent heat exchange with the combined and split streams as described above, but the separation conditions are such that the feed stream before being split into separate streams is The temperature is adjusted to over 410 degrees by exchanging heat with.

In a preferred embodiment of the invention, the reaction product is divided into sub-streams, each sub-stream being divided into separate streams, each mixed stream before being fed to the furnace in a respective heat exchanger upstream of the furnace, and a separate stream which receives heat for cooling. However, before entering the separator, the reaction product enters another heat exchanger and undergoes heat exchange with the feedstock.
Regulation of the zero separation temperature, which is cooled to a preset separation temperature, is controlled by bypassing the heat exchanger with a metered portion of the feedstock. Preferably, the temperature of the reaction product exiting the heat exchanger is monitored, and a valve provided in the bus line is controlled in response to the monitored temperature.

In order to explain the present invention in more detail, comparative examples and examples are shown below.

FIG. 1 is a schematic process diagram for explaining a comparative example based on a known technique, and FIG. 2 is a schematic process diagram for explaining the present invention in detail.

Comparative Example This concerns a known technique for the conversion of hydrocarbon cuts in the presence of a hydrogen-containing gas and one or more catalysts.

As shown in FIG. 1, a heat exchanger A in which a heavy petroleum fraction 1 at a temperature of 483 degrees and a hydrogen-containing gas 2 at a temperature of 433 degrees and a pressure of 6.84 MPa are mixed and connected in series; B
, C, D, and E to 633 degrees K and distributed in an uncontrolled manner as four separate streams into the furnace passage lines at the furnace F inlet.

Each substream is heated in the furnace F, and when recombined at the furnace outlet, the temperature of the mixture reaches 668 degrees K.

As a result of the uneven distribution of the gas-liquid mixture, the temperatures at the furnace outlet of each passage line differ from each other and are 703 degrees K, 850 degrees K, 683 degrees K, and 658 degrees.

A hydrogenation catalytic reaction then takes place in one reactor G at a pressure of 8.0 MPa.

Since the reaction taking place in the reactor is predominately exothermic, the reaction product mixture leaves the reactor at 883 degrees and passes through heat exchanger E.
, D, C, B, and A, and is cooled to a temperature of 513 degrees K for separation in high temperature separator H.

This temperature is suitable from an energetic point of view for the separation of the gas 3 and liquid 4 products.

Regulation and maintenance of the desired temperature of 513 degrees in the high temperature separator H is achieved by partially bypassing the heat exchangers A, B, C, D and E, i.e. the heavy petroleum fraction l
A partial stream of is added to the gas-liquid mixture just before the inlet of the furnace F, bypassing the heat exchanger bank.

The ratio of the pressure of gas stream 2 upstream of the mixing point and the pressure of gas stream 3 leaving hot separator H is critical for the compression of the circulating hydrogen-containing gas, and this ratio is 13.84 MPa.
/ 5.82MPa = 1.21708 te. The pressure difference is 1.22 MPa.

These figures refer to 180 days of operation of the plant with a feed of 200 m3/h of heavy petroleum fraction and 8000 m3iN/h of hydrogen-containing gas.

This gas volume is equal to the initial gas volume of eoo per hour.

m3iN was adjusted on day 124 after the plant had to be shut down on day 118 due to a blockage in the furnace passage line.

Example This concerns the method according to the invention.

As shown in Figure 2, heavy petroleum fraction 1 at 483 degrees
is heated to 503 degrees K in heat exchanger A tube by heat exchange with the reaction product mixture.

Fraction l is then divided into four equal sub-streams by flow control, and then a hydrogen-containing gas stream at 6,38 MPa and 433 degrees, which is also divided into four equal parts by flow control. It is mixed with 2.

The mixture is first passed through 633 in four parallel passage lines in each of heat exchangers B, C, D and E.
The reactor is heated to a temperature of 888 degrees, which is the reactor inlet temperature, in a heating furnace F with four parallel pipes.

The furnace outlet temperature for each passage line is 668.
8, 8B? , 7, 888.1 and H 7.5 degrees, which are very close to each other, demonstrating a very even distribution of the gas-liquid mixture into the furnace passage, and the flow rate Local overheating due to differences cannot occur.

Hydrogen catalytic conversion takes place in the reactor at e, 0 MPa.

The reaction product mixture leaves the reactor at 883 degrees and is cooled to 538 degrees K in the shells of heat exchangers B, C, D, and E.

Energy-favorable separation conditions for the separation of gas stream 3 and liquid product stream 4 in high temperature separator H are
The device A is provided with the possibility of partial bypass of the heavy petroleum fraction stream I.

High temperature separator H operates at 513 degrees and 5.84 MPa.

Hydrogen-containing gas stream 2 upstream of mixing with heavy petroleum fractions
The ratio of the pressure of the gas to the pressure of the gas stream 3 flowing out from the high temperature separator H is 6.38 MPa / 5.84 MPa -1,0
It is 811104.

The pressure difference is 0.52 MPa.

These figures correspond to a heavy petroleum distillate supply of 200 m/h,
This is the 180th day of operation of the plant in a state where the circulating hydrogen-containing gas is 8000 m3iN per hour. Until this date, the plant has been operated continuously without any failures.

The advantages of this invention compared to comparative examples are as follows.

(1) Reliable and trouble-free operation when supplying the heaviest petroleum fractions and minimizing hydrogen-containing gas circulation values.

, (2) 25% reduction in the minimum required amount of circulating gas.

(3) Prevention of local overheating in the furnace tubes due to unbalanced supply of reaction components and thereby prevention of passage line blockage and/or large increase in pressure loss in the furnace and reactor.

(4) Reduction in the tendency of reactants to coke and thereby prolonging the life of the catalyst.

(5) Achieving improved product quality or higher conversion rates.

(6) 60% reduction in compression energy consumption due to lower energy consumption due to 25% reduction in required circulating gas volume and lower inlet-to-outlet pressure ratio.

[Brief explanation of drawings]

FIG. 1 is a flow sheet for the hydrothermal catalytic conversion step of a hydrocarbon fraction according to a conventional method, and FIG. 2 is a flow sheet for the method according to the present invention. 1, Treated petroleum fraction 2, Hydrogen-containing gas 3, Gas 4, Product A, Heat exchanger B, Same as C3, Same as same as Same E, Same as F, Heating furnace G0 Reactor Page 1 continued 0 Inventor Heinz・Rimmer, German Democratic Republic of Germany 1330 Schhet, Eng.--Thälmannstrasse 168 0 Inventor Unilner Rosenkrantz German Democratic Republic of Germany 7202 Heeren Klaratszetkinstrasse 6 @l! Intermediate Hartmud Schuster - German Democratic Republic of Germany 1330 Schubet FE Lufurfuring 26 0 Inventor Georg Team German Democratic Republic of Germany 1330 Schubbet Breitscheidtstrasse 21

Claims (1)

[Claims] The raw material to be converted is divided by flow control into at least two branch streams, the same number as the number of pipes passing through the heating furnace upstream of the reactor, and the hydrogen-containing gas is also controlled at a hydrogen partial pressure of 0.7 MPa or more and a temperature of 520 degrees or less. The sub-stream is divided into the same number of sub-streams as the sub-stream by flow control, and each of the sub-streams is mixed with the corresponding raw material sub-stream to form a mixed sub-stream group, and each of the mixed sub-streams is divided into the same number of sub-streams as the sub-stream, and each of the sub-streams is mixed with the corresponding raw material sub-stream to form a mixed sub-stream group, and each of the mixed sub-streams is divided into the same number of sub-streams as the sub-stream. The temperature of the mixed stream is raised to a predetermined reaction temperature by countercurrent heat exchange with the reactor and subsequent heating in a heating furnace of a multi-pass pipe, and the heated mixed stream is then led to a reactor to react. It is cooled by countercurrent heat exchange with the mixed branch group and subsequent heat exchange with the raw material stream before being divided into the branch streams, and the cooling temperature is 41
Hydrorefining and/or hydrocracking process in the presence of a hydrogen-containing gas and one or more catalysts, the temperature being adjusted to above 0°C, and characterized in that the reaction mixture is separated together with the unreacted stream after contact. Partially or fully liquid hydrocarbons are converted into fuel oil components, fuel components, feedstocks for fuel production, or feedstocks and intermediates for the petrochemical industry. Method for converting hydrocarbon fractions.