RU2643954C1 - Method of obtaining oil medium-temperature binding and impregnation pitches - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method of producing oil medium-temperature binders and impregnating pitches is described, consisting of the stages of thermopolycondensation of the fraction of pyrolysis resin at the temperature of 360-390°C and pressure of 1.0-2.5 MPa in the flow reactor and subsequent isothermal holding of the reaction mass with the distillation of the low molecular weight components in the reactor-separator, in which fraction of 230°C is used as fraction of pyrolysis resin, during the thermopolycondensation of the raw material in the flow reactor the non-oxidizing agent - the superheated steam is excluded, the isothermal holding process of the reaction mass followed by thermal polycondensation and distillation of low molecular weight components is carried out in a reactor-separator at a temperature of 320-380°C and pressure of 0.1-0.2 MPa for 6 -10 hours and by bubbling by natural gas, at gas consumption of 0.015-0.025 kg/h per kg of raw material.

EFFECT: simplified method for obtaining oil medium-temperature binder and impregnation pitch with a high yield is proposed.

1 dwg, 2 tbl, 2 ex

Description

The invention relates to the field of oil refining, in particular to a method for producing oil pitch, and can be used in the petrochemical and oil refining industries for the production of binders and impregnants.

A known method of producing oil pitch by thermopolycondensation of oil raw materials [Belgian patent No. 893465, class. С10С 3/02, С10С 3/04, publ. 09/12/1982], in particular pyrolysis resins, under pressure up to 15 atm at 290-420 ° С (preferably 300-410 ° С) for 10 min-6 hours, followed by distillation of low molecular weight products, the temperature difference between the hot bottom of the reactor and colder top is from 20 to 200 ° C and holding in the second reactor at a temperature of 290-420 ° C in the presence of water vapor for 5 minutes - 2 hours. Steam is consumed in an amount of from 0.3 to 3 m ³ / h ⋅ per m ^{3 of the} reaction mass.

The disadvantages of this method are the complexity of the process, in particular, maintaining a temperature difference, the relatively low yield of fiber-forming pitch and its low quality.

A known method of producing oil isotropic fiber-forming pitch [RF patent No. 2065470, class. C10C 1/16, publ. 08/20/1996. Bull. No. 3], including thermal polycondensation of crude oil at elevated pressure in a flow reactor, distillation of low molecular weight reaction products in the presence of a non-oxidizing agent. Moreover, the initial pyrolysis resin is first subjected to ultrasound treatment in the presence of surface-active substances (surfactants), then thermopolycondensation in a flow-type reactor at 20-50 atm and then distillation of low molecular weight reaction products in a separator when a non-oxidizing agent is supplied at a speed of 375-10000 l / h at 300-360 ° C. As a surfactant taken in an amount of 0.1-0.5% by weight of the raw material, a mixture of polyethylene glycol with an average molecular weight of 400 and polyethylene glycol adipate in a weight ratio of 60: 40-80: 20 is used. Ultrasonic treatment provides optimal dispersion of surfactants in the initial pyrolysis resin. The method improves the quality of the pitch and productivity due to the continuity of the process. The disadvantages of this method are the use of surfactants, insufficiently high yield fiber-forming pitch due to insufficient residence time of the reaction mass in the reaction zone in connection with the stage of thermopolycondensation at elevated pressure only in a flow-through coil reactor.

Closest to the proposed method according to the technical result is a method for producing petroleum low-melting binder and fiber-forming pitch [Mukhamezyanova A.A., Gimaev R.N., RF patent No. 2477744, cl. C10C 1/16, publ. 03/20/2013. Bull. No. 8] by thermopolycondensation of heavy pyrolysis resin purified from low-boiling and non-melting components at elevated pressure and temperature of 330-400 ° C, distillation of low molecular weight reaction products and holding the resulting product at elevated temperature in the presence of superheated water vapor as a non-oxidizing agent. The reaction mass is in the reaction zone for a predetermined time by its recirculation at a pressure of 10-25 atm, then part of the reaction mass is sent to the reaction separator for distillation of low molecular weight reaction products at a flow rate of superheated water vapor in an amount of 0.02-0.04 kg / hour per kg TSP and holding at a temperature of 340-380 ° C for 3-10 hours to obtain a low-melting binder pitch, then the low-melting binder pitch is sent to a vacuum column to distill off the low molecular weight reaction products and holding at 300-320 ° C and a pressure of 20-50 mm r . Art. within 2-5 hours at a flow rate of superheated water vapor in an amount of 0.02-0.04 kg / h per kg of raw material to obtain a high-melting pitch melt, the obtained melt is treated with ultrasound with a frequency of 15-22 kHz and a power of 50-100 W / cm ² to obtain a high melting fiber-forming pitch. The distillates of low molecular weight reaction products are sent to an atmospheric column for water separation and separation to produce hydrocarbon gases, gasoline, light and heavy gas oil, then heavy gas oil after heating to a temperature of 480-540 ° C is sent to the mixer. Low melting binder pitch can be assigned as an independent commercial product.

The disadvantages of the method are

- the use of a large amount of superheated water vapor as a non-oxidizing agent at all stages of the technological scheme, leading to high energy costs, the problem of waste water disposal and the need to introduce additional processing equipment for separating water and drying by-product distillate products;

- low yield and unsatisfactory quality of the non-target product - a binder of high temperature pitch, due to the use of a fraction of the heavy pyrolysis resin with n.k. 250 ° C and insufficient isothermal exposure of the reaction mass in the separator.

The aim of the invention is to obtain a medium-temperature oil binder and impregnating pitch with specified physico-chemical characteristics (table 1) with a high yield, the simplification of the process.

The goal is achieved by the proposed method for producing medium-temperature oil binder and impregnation pitch, consisting of stages of thermopolycondensation of the pyrolysis resin fraction at a temperature of 360-390 ° C and a pressure of 1.0-2.5 MPa in a flow reactor and subsequent isothermal exposure of the reaction mixture with distillation of low molecular weight components in a separator reactor, characterized in that

- as a fraction of the pyrolysis resin using a fraction of n. K. 230 ° C,

- during thermopolycondensation of the feedstock in a flow reactor, a non-oxidizing agent is excluded - superheated water vapor,

- the process of isothermal aging of the reaction mass, accompanied by thermal polycondensation and distillation of low molecular weight components, is carried out in a separator reactor at a temperature of 320-380 ° C, a pressure of 0.1-0.2 MPa for 6-10 hours with sparging with natural gas, at a gas flow rate in an amount of 0.015-0.025 kg / h per kg of soft pitch. Natural gas has the following composition: CH ₄ - 98%, C ₂ H ₆ - 2%.

The essence of the proposed method is as follows. The heavy pyrolysis resin (table 2), a by-product of ethylene production, with a boiling point of approximately 200 ° C, is subjected to fractionation in a distillation column, from the top of which low-boiling fractions of pyrolysis resin are removed, and from the bottom a heavy fraction with a temperature of n. K. 230 ° C, or soft pitch with a softening temperature according to KiSh 30-80 ° C.

Removal of low-boiling components of TSP (bp to 230 ° С) reduces gas evolution during the process of thermopolycondensation, improves the quality of target oil medium-temperature binder and impregnation pitch by reducing their porosity. The use of pyrolysis resin fractions with a temperature of n K. 250 ° C in the prototype excludes from the reaction zone of thermopolycondensation about 25% of the reactive polycycloaromatic components of the initial pyrolysis resin (see table 2), in the proposed method, the use of a fraction of pyrolysis resin with a temperature of n. K. 230 ° C corrects this, which allows to increase the output of medium-temperature oil binder and impregnating pitch.

The exposure in the reactor-separator carbonized mass, heated in a flow reactor, at a temperature of 320-380 ° C, a pressure of 0.1-0.2 MPa for 6-10 hours with sparging with natural gas (at a gas flow rate of 0.015-0.025 kg / hour per kg of soft pitch) and simultaneous distillation of low molecular weight products of the process provides optimal conditions for the production of medium-temperature oil binder and impregnating pitch.

Lowering the temperature of isothermal holding to 320 ° C compared with the prototype (340 ° C) allows you to control the rate of thermolysis and the quality of the target product.

The process at a temperature below 320 ° C for a duration of less than 6 hours leads to a decrease in the yield of the target product due to the incomplete occurrence of the thermopolycondensation reaction.

An increase in temperature above 380 ° C and a holding time of more than 10 hours leads to a pitch that does not meet the requirements for oil medium-temperature binders and impregnating peaks by group composition (table 1).

An increase in the duration of isothermal aging of the reaction mass for more than 10 hours leads to a pitch that meets the physicochemical characteristics of the requirements for medium-temperature oil binder and impregnation peaks (table 1).

The exclusion of the supply of superheated water vapor at the stage of heat treatment of soft pitch in a flow reactor allows to reduce the energy consumption for receiving water vapor, the cost of installing equipment for receiving, storage and supply, as well as additional equipment for drying distillate products of the process and to remove the stage of wastewater treatment.

Sparging with natural gas in the separator reactor provides uniform mixing of the mixture components, reducing stagnation of the carbonizing mass and coking of the walls of the reactor, improving the quality of the commercial product. The use of natural gas as a bubbling agent instead of superheated water vapor during isothermal aging in a separator reactor reduces the energy consumption for producing water vapor, the cost of installing additional equipment for drying distillate process products and wastewater treatment. The consumption of natural gas is less than 0.015 kg / h per kg of soft pitch does not ensure maintaining the temperature of the reaction mass within 320-380 ° C and its intensive uniform mixing. An increase in the consumption of natural gas of more than 0.025 kg / h per kg of soft pitch does not affect the group composition and softening temperature of the target pitch and is not economically feasible.

Schematic diagram of the production of medium-temperature oil binder and impregnating pitch is shown in Fig. one,

where 1 is a pyrolysis resin preparation unit, 2 is a tube furnace, 3 is a mixer, 4 is a flow reactor, 5 is a separator, 6 is a reactor-separator, 7 is a cooling, condensation and separation system for low molecular weight heat treatment products.

Streams: I - heavy pyrolysis resin into the preparation unit, II - light fraction of pyrolysis resin, III - soft oil pitch (heavy fraction of pyrolysis resin with a temperature of N ° 230 ° C), IV - soft pitch heated in the furnace, V - reaction mass from the mixer to the flow reactor; VI — reaction mass from the flow reactor to the separator; VII - distillation of low molecular weight products of heat treatment of a flow reactor; VIII - the reaction mixture from the separator; IX - the reaction mixture from the separator to the circulation, X - the reaction mixture from the separator to the reactor-separator, XI - natural gas, XII - the target oil medium temperature binder or impregnation pitch, XIII - gas-vapor mixture of low molecular weight heat treatment products, XIV - hydrocarbon gases, XV - gasoline, XVI - light distillate with a boiling point below 350 ° C, XVII - heavy distillate with a boiling point of 350-450 ° C.

The heavy pyrolysis resin I enters preparation unit 1, where it is separated into light II and heavy fraction III with a temperature of n. K. 230 ° C (hereinafter soft pitch). Soft pitch stream III is served in a tubular furnace 2, where it is heated under a pressure of 1.9 MPa to a temperature of 280-390 ° C. Next, the heated soft pitch IV enters the mixer 3, where it is mixed with the recycle reaction mass, and by stream V the mixture is fed to the flow reactor 4, where the raw materials are heat treated at a temperature of 360-390 ° C and a pressure of 1.0-2.5 MPa. From the flow reactor 4, the reaction mass by stream VI enters the separator 5 for distillation of low molecular weight heat treatment products VII. The resulting liquid reaction mass VIII is separated, part of the reaction mass from the separator 5 is returned to the mixer 3 by stream IX, the balance amount of the reaction mass X is discharged into one of the three separator reactors 6 operating periodically, the whole circuit works continuously. In the separator reactor 6, the distillation of low molecular weight reaction products occurs due to pressure reduction to 0.1-0.2 MPa. After filling one separator reactor, it is disconnected from the reaction mass supply line, which is sent to the next separator reactor. In the separator reactor 6, the process of isothermal holding is carried out at a temperature of 320-380 ° C, a pressure of 0.1-0.2 MPa and sparging of natural gas XI with a mass flow rate of 0.015-0.025 kg / h per kg of raw material. In this case, thermodestructive condensation of the liquid reaction mass and distillation of low molecular weight components occur.

Isothermal exposure of the reaction mass in the separator reactor 6 is continued until an oil medium temperature binder or impregnation pitch XII with the required quality indicators is obtained. The physicochemical properties of the pitch are adjusted to those necessary by adjusting the temperature, duration of exposure, and blast speed of natural gas. After reaching the desired degree of conversion, the reaction mass from the separator reactor 6 is withdrawn in the form of the target product XII. The distillation of low molecular weight thermopolycondensation products from the separator reactors 6 by stream XIII is fed to column 7, where it is subjected to fractionation under reduced pressure to obtain hydrocarbon gases XIV, gasoline XV, light XVI and heavy gas oil XVII.

The resulting oil sands are analyzed by the following quality indicators:

- softening temperature according to the method of "ring and rod", GOST 9950-83;

- content of α ₁ fraction insoluble in quinoline, GOST 12000-83;

- the content of the α-fraction insoluble in toluene, GOST 7847-73;

- ash content; GOST 7846-73;

- volatile release; GOST 9951-73;

- sulfur content, GOST 1437-75.

The proposed method is illustrated by examples. Pyrolysis resin was used as a raw material for the production of oil pitch (table 2).

Example 1. Soft pitch in an amount of 50 kg at a temperature of 200 ° C is continuously fed with a mass flow rate of 10 kg / h into a tube furnace, where it is heated to a temperature of 275 ° C at a pressure of 1.9 MPa. The heated soft pitch is fed to a mixer, where it is mixed with a recycle reaction mass and then sent to a flow reactor (temperature 375 ° C, pressure 1.7 MPa). From the flow reactor, the reaction mass is withdrawn at a rate of 10 kg / h into a separator, from which low molecular weight heat treatment products and a liquid reaction mass are withdrawn.

Part of the reaction mass from the separator is returned to the mixer, the balance amount of the reaction mass is discharged into one of the three separator reactors operating periodically. In the reactor-separator, the mixture is maintained at a temperature of 380 ° C and a pressure of 0.1 MPa for 9 hours. To separate the reaction products and remove low molecular weight components, natural gas is fed countercurrently to the reactor separator, the gas flow rate to the reactor separator is 0.025 kg per kg of raw material / hour. The resulting pitch is fed to the warehouse for packaging. Low molecular weight reaction products are sent to a column for separation into heavy and light gas oils, hydrocarbon gases and gasoline.

As a result of the process, 20.8 kg of pitch were obtained with a softening temperature (in terms of C&C) of 78 ° C, an ash content of 0.3, a molecular weight of 423, a yield of volatile 65, an α-fraction of 16.7 and a sulfur content of 0.3% wt., Α ₁ fraction was absent. The output of the pitch was 41.6% of the mass., On a soft pitch. According to the physicochemical characteristics, the resulting pitch corresponds to an oil medium temperature binder pitch (see table 1).

Example 2. Soft pitch in an amount of 50 kg at a temperature of 200 ° C is continuously fed with a mass flow rate of 10 kg / h into a tube furnace, where the initial resin is heated to a temperature of 300 ° C at a pressure of 1.9 MPa. The heated resin is fed into the mixer, where it is mixed with the recycle reaction mass, and then sent to the flow reactor (temperature 380 ° C, pressure 1.0 MPa). From the flow reactor, the reaction mass is withdrawn at a rate of 10 kg / h into a separator, from which low molecular weight heat treatment products and a liquid reaction mass are withdrawn.

Part of the reaction mass from the separator is returned to the mixer, the balance amount of the reaction mass is discharged into one of the three separator reactors operating periodically. In the reactor-separator, the mixture is maintained at a temperature of 370 ° C and a pressure of 0.1 MPa for 9 hours. To separate the reaction products and remove low molecular weight components, natural gas is fed countercurrently to the reactor-separator, the gas flow to the reactor-separator is 0.015 kg per kg of raw material / hour. The resulting pitch is fed to the warehouse for packaging. Low molecular weight reaction products are sent to a column for separation into heavy and light gas oils, hydrocarbon gases and gasoline.

As a result of the process, 22.6 kg of oil pitch with a softening temperature of 83 ° C, an ash content of 0.3, a molecular weight of 451, a yield of volatile 63, an α-fraction of 16.3 and a sulfur content of 0.3% by mass, α ₁ fraction, were obtained. was absent. The output of the pitch was 45.2% of the mass., On a soft pitch.

According to the physicochemical characteristics, the resulting pitch corresponds to an oil medium temperature impregnating pitch.

From the examples it follows that the method allows:

- receive oil medium temperature binders and impregnating peaks;

- to increase the output of medium-temperature oil binders and impregnating pitch due to the use of heavy pyrolysis resin fractions with n. K. 230 ° C and natural gas as a bubbling agent;

- improve the economic and environmental performance of the process by abandoning the use of superheated water vapor during heat treatment of soft pitch in a flow reactor and replacing it with natural gas for bubbling in a separator reactor.

Claims (1)

A method of producing oil medium-temperature binders and impregnating pitch, consisting of stages of thermopolycondensation of the pyrolysis resin fraction at a temperature of 360-390 ° C and a pressure of 1.0-2.5 MPa in a flow reactor and subsequent isothermal exposure of the reaction mixture with distillation of low molecular weight components in a separator reactor characterized in that as a fraction of the pyrolysis resin using a fraction of n. K. 230 ° C, during the passage of thermopolycondensation of raw materials in a flow reactor, a non-oxidizing agent is excluded - superheated water vapor, and the process of isothermal aging of the reaction mass, accompanied by thermal polycondensation and distillation of low molecular weight components, is carried out in a separator reactor at a temperature of 320-380 ° C, pressure 0 , 1-0.2 MPa for 6-10 hours and sparging with natural gas, with a gas flow rate of 0.015-0.025 kg / h per kg of raw material.

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