CN1209441C - Separation method of catalytic gasoline quality improved oil and gas and its installation - Google Patents

Abstract

The invention discloses a separation method and device for catalytic gasoline modified oil and gas. The separation process is as follows: the modified oil and gas enter a simple fractionation tower, the catalyst washing and desuperheating section at the bottom contacts with the oil slurry countercurrently, and the catalyst powder is washed and exchanged. heat; and then upward into the rectification section of the fractionation tower for the separation of diesel fraction, gasoline fraction and cracked gas. The separation process may be as follows: the modified oil gas enters a simple washing tower for countercurrent contact heat exchange with the oil slurry and washes the catalyst powder; then enters the steam generator to recover the high temperature potential heat of the modified oil gas again, and finally enters a simple fractionating tower for diesel fractionation, Separation of gasoline fractions and cracked gases. After heat exchange, the oil slurry enters the steam generator to recover high-temperature potential heat. The invention has the technological advantages of being able to recover high-temperature heat, reduce process energy consumption, simple process, less investment, stable and convenient operation, and easy realization. It can effectively separate catalytic cracked gasoline modified oil and gas, and reduce the olefin content of catalytic gasoline to 25(v)% or less, and keep the octane number unchanged, which can meet the requirements of environmental protection regulations.

Description

Separation method and device for catalytic gasoline reforming oil and gas

technical field

The invention relates to a separation process of petroleum hydrocarbons, in particular to a process technology for catalytic gasoline modified oil-gas separation, and belongs to the field of petrochemical technology.

Background technique

With the increasingly stringent environmental protection requirements, the standards for harmful substances in gasoline require that the olefin content in gasoline ≯35(v)%, the octane number (research method)≮90, the aromatic content≯40(v)%, and the sulfur content≯800ppm , and stipulated that it will be implemented nationwide on January 1, 2003. At present, catalytic cracking gasoline is still the main gasoline used in vehicles, and some data show that catalytic cracking gasoline accounts for as high as 85% of the finished gasoline. The volume fraction of olefins in FCC gasoline is 45%-60%, which is much higher than the gasoline standard of new formula. Due to the active chemical properties of olefins, they volatilize and mix with NO _x in the atmosphere, and form toxic photochemical smog mainly composed of ozone after being irradiated by ultraviolet rays from the sun, causing serious pollution to the atmosphere; in addition, when the content of olefins in gasoline is high, it will cause electricity. Injection engine nozzles and feed valves have serious carbon deposits, resulting in control deviations and increased fuel consumption. Therefore, reducing the olefin content in gasoline has become an urgent task in the current oil refining industry. In order to reduce the olefin content of catalytic cracking gasoline, the oil refining industry generally adopts the following measures: pre-hydrogenation of catalytic raw materials; use of catalysts for reducing olefins in catalytic cracking; optimization of operating conditions of catalytic cracking units. However, the effects of these methods are limited, and the olefin content in gasoline is reduced by 10-12 volume percentage points at most, which cannot meet the requirements of the new gasoline standard. Some research reports on the separate modification of FCC gasoline are also mainly means to reduce the olefin content of FCC gasoline, such as light gasoline etherification, FCC gasoline desulfurization and olefin reduction, FCC gasoline hydroisomerization aromatization and catalytic Cracked gasoline hydrodesulfurization-reforming, etc. These methods and technologies or processes are complex and require a large investment. Many refineries still have great difficulties in adopting them, or the process technology is immature and has no industrial application.

In order to effectively reduce the olefin content of catalytic cracking gasoline and meet the requirements of environmental regulations and new gasoline standards, it has been proposed to set up auxiliary risers or auxiliary reactors on conventional catalytic cracking units to further upgrade catalytic cracking gasoline, and has been Related patents have been applied for, including: simple method and device for upgrading and reducing olefins in catalytic cracking gasoline, application number: 02116786.9; method and system for reducing olefin content in catalytic cracking gasoline, application number: 02123817.0 Method and device for upgrading octane number, application number: 02123655.0, method and system for reducing olefin content of catalytic cracked gasoline and maintaining octane number, application number: 02123494.9, upgrading method and device for reducing olefins in catalytic gasoline and increasing octane number , Application No.: 02123658.9, method and device for reducing the olefin content of FCC gasoline, application No.: 02116787.7. These methods and devices for reducing the olefin content of catalytically cracked gasoline use auxiliary risers or auxiliary reactors to mix and contact the high-temperature regenerant with catalytic gasoline in the normal temperature liquid phase to perform hydrogen transfer, aromatization, isomerization and cracking modification reaction to generate upgraded oil and gas. In the above invention patent, there are two methods for the separation of upgraded oil and gas. One is to mix with the main reaction oil and gas of catalytic cracking in the settler of the original catalytic cracking unit and then enter the main fractionation tower, and then carry out corresponding separation; the other is to enter into a separate establishment The simple fractionation system for separation can refer to the invention patent: Upgrading method and device for deeply reducing olefins and increasing octane number of catalytic cracked gasoline, application number: 02123655.0, upgrading method and device for catalytically reducing olefins and increasing octane number of catalytic gasoline, application No.: 02123658.9, method and device for reducing olefin content in catalytic cracked gasoline, application No.: 02116787.7. Since the fraction composition of catalytic cracking gasoline modified oil gas is significantly different from that of conventional catalytic cracking reaction oil gas, it contains 5-10wt% cracked gas, 85-95wt% gasoline fraction and 1-5wt% diesel fraction, and also contains a small amount of catalyst Powder, therefore, in order to effectively separate this part of the modified oil and gas, and to recover high-temperature heat and reduce process energy consumption, a specially designed separation system must be used.

Contents of the invention

The main purpose of the present invention is to provide a separation method and device for catalytic gasoline modified oil and gas, which can effectively separate the modified oil and gas, reduce the content of olefins, and keep the octane number unchanged.

Another object of the present invention is to provide a separation method and device for catalytic gasoline modified oil and gas, which can recover high-temperature heat as much as possible while separating modified oil and gas, and reduce process energy consumption.

And ensure that the process is simple and easy to operate.

The purpose of the present invention is achieved through the following technical solutions.

Wherein, a kind of technical scheme of method is:

A method for separating catalytic gasoline modified oil and gas, the separation process of modified oil and gas is as follows:

Step 1: The upgraded oil and gas are taken out from the catalytic cracking gasoline auxiliary riser or auxiliary reactor and then enter a simple fractionation tower. The catalyst washing and desuperheating section at the bottom is in countercurrent contact with the oil slurry from the original catalytic cracking unit, and the catalyst powder is washed and processed. Heat exchange, after the oil slurry heat exchange temperature rises, it is drawn from the bottom of the fractionation tower into the oil slurry steam generator to recover high-temperature heat, and then returns to the riser reactor of the original catalytic cracking unit;

Step 2: The washed oil gas enters the rectification section of the fractionation tower upwards to separate diesel fraction, gasoline fraction and cracked gas.

Another technical solution of the method is:

A method for separating catalytic gasoline modified oil and gas, the separation process of modified oil and gas is as follows:

Step 1: The upgraded oil gas is led out from the catalytic cracking gasoline auxiliary riser or auxiliary reactor and then enters a simple washing tower, and conducts countercurrent contact with the oil slurry from the original catalytic cracking unit to exchange heat and wash the catalyst powder, and the oil slurry enters the steam generator To recover high-temperature heat, and then return to the riser reactor of the original catalytic cracking unit;

Step 2: The washed oil gas enters the steam generator to recover the high-temperature potential heat of the upgraded oil gas, and finally enters a simple fractionation tower to separate diesel fraction, gasoline fraction and cracked gas.

In the above two technical schemes, the conditions of the upgrading oil-gas separation process are:

Tower top temperature: 80-120°C; diesel fraction extraction temperature: 170-250°C; tower top pressure: 0.08-0.12Mpa gauge pressure; the modified oil and gas at least includes the whole fraction of naphtha in catalytic cracking unit or a distillation range greater than The heavy fraction of naphtha at 60°C or the light fraction of naphtha with a distillation range less than 110°C is obtained through the catalytic upgrading process; the catalyst includes any catalyst in the catalytic cracking process, which is an amorphous silica-alumina catalyst or a molecular sieve catalyst or a fluidized Catalytic upgrading catalyst; and the separated cracked gas enters the inlet of the rich gas compressor of the original catalytic cracking unit, the separated gasoline fraction enters the absorption and stabilization system of the original catalytic cracking unit, and the separated diesel fraction goes to the original catalytic cracking unit for absorption and stabilization The system's gasoline stabilization tower acts as an absorbent.

A kind of technical scheme of device of the present invention is:

A separation device for catalytic gasoline reforming oil and gas, the device includes: the top of an auxiliary riser or auxiliary reactor is connected to the bottom of a simple fractionation tower; wherein, the bottom of the simple fractionation tower is connected in turn to a slurry pump, a slurry steam generator The middle part of the fractionation tower is connected with a diesel pump, and the top of the fractionation tower is connected with an oil-gas condenser and an oil-gas separation tank in turn.

Another implementation of the device of the present invention is:

A separation device for catalytic gasoline reforming oil and gas, the device includes: the top of an auxiliary riser or auxiliary reactor is connected to the bottom of a simple washing tower; wherein, the bottom of the washing tower is connected to a slurry pump and a slurry steam generator in sequence , the top of the scrubber is connected to the simple fractionation tower through a steam generator; the bottom of the simple separation tower is connected to a diesel pump, and the top is connected to an oil-gas condenser and an oil-gas separation tank in turn.

Through the above technical solutions, the technological advantages of the present invention are: high-temperature heat can be recovered, process energy consumption can be reduced, the process is simple, the investment is small, the operation is stable and convenient, and it is easy to realize. It can effectively separate the modified oil and gas of the catalytic cracking gasoline, reduce the olefin content of the catalytic gasoline to less than 25 (v)%, and keep the octane number unchanged, which can meet the requirements of the national environmental protection regulations.

Description of drawings

Fig. 1 is a schematic diagram of an embodiment of a device system forming a process flow of the present invention;

Fig. 2 is a schematic diagram of another embodiment of the device system composition process flow of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing and specific embodiment:

Example 1:

The separation process of the upgraded oil and gas is shown in Figure 1: the upgraded oil and gas 2 with a temperature of 350-500°C drawn from the top of the catalytic cracking gasoline auxiliary riser or the auxiliary reactor 1 enters the catalyst washing and degassing device located at the lower part of the simple fractionation tower 3. The lower part of the superheating section 4 is used for washing and exchanging heat with the heat-exchanged oil slurry 5 drawn from the original catalytic cracking unit. The upper part of the introduction. Then the oil slurry 5 is drawn from the bottom of the fractionation tower through the oil slurry pump 6 and enters the oil slurry steam generator 7 to recover high-temperature heat, then enters the heat exchanger 8 for heat exchange, and then returns to the riser reactor of the original catalytic cracking unit to control oil The temperature of the oil slurry before the slurry pump 6 is 280-350°C. An extraction line for diesel fraction is set up in the middle of simple fractionation tower 3, diesel fraction 10 is extracted by diesel pump 9, and the temperature of diesel extraction is controlled to be 220-250°C. An oil-gas condenser 11 and an oil-gas separation tank 12 are set up at the top of the fractionating tower 3 to separate the cracked gas 13 and the gasoline fraction 14. The cracked gas 13 can enter the inlet of the rich gas compressor of the original catalytic cracking unit, and a part of the gasoline fraction 141 returns to fractionation The top of tower 3 is used as the top reflux, and the remaining part 142 enters the absorption stabilization system of the original catalytic cracking unit. The catalyst washing and desuperheating section 4 in the lower part of the fractionation tower can be provided with 3 to 10 layers of herringbone baffles, and the interior of the fractionation tower can be provided with 5 to 30 layers of trays.

Example 2:

The separation process of the upgraded oil and gas can also be the way shown in Figure 2: the upgraded oil and gas 2 with a temperature of 350-500 ° C drawn from the top of the catalytic cracking gasoline auxiliary riser or the auxiliary reactor 1 enters a simple washing tower 15. The lower part is in countercurrent contact with the oil slurry 5 that comes from the fractionation tower of the original catalytic cracking unit and entered from the top of the simple washing tower 15 through heat exchange, and carries out countercurrent contact in the simple washing tower to perform heat exchange and washing of catalyst powder, and the temperature rises after the heat exchange The oil slurry 5 is pumped into the oil slurry steam generator 7 through the oil slurry pump 6 to recover high-temperature heat, and then returns to the riser reactor of the original catalytic cracking unit. The simple washing tower 15 can be equipped with 2 to 10 layers of herringbone baffles. The temperature of the oil slurry from the fractionation tower of the original catalytic cracking unit is 300-340°C, and the temperature of the oil slurry and the modified oil gas after heat exchange is 360-420°C. The washed oil and gas 2 enters the steam generator 16 to further recover the high-temperature potential heat of the upgraded oil and gas. After the temperature is lowered to 250-300°C, it enters the middle and lower part of a simple fractionation tower 3. At the bottom of the simple fractionation tower 3, a diesel pump 9 is used. The diesel fraction 10 is drawn out, and the gasoline stabilization tower of the absorption stabilization system of the original catalytic cracking unit can be used as an absorbent. Control the diesel oil extraction temperature to 220-250°C. At the top of the simple fractionation tower 3, the oil gas 2 is introduced into the oil-gas condenser 11 and the oil-gas separation tank 12 to separate the cracked gas 13 and the gasoline fraction 14, and the cracked gas 13 can enter the inlet of the gas-rich compressor of the original catalytic cracking unit, and the gasoline fraction 14 A part returns to the top of the simple fractionation tower 3 as reflux 141, and the other part 142 enters the absorption stabilization system of the original catalytic cracking unit. The simple fractionation tower 3 can be provided with 5 to 30 layers of trays.

The upgraded oil and gas can be obtained by upgrading catalytic cracking gasoline with any catalyst in the catalytic cracking process, for example, an amorphous silica-alumina catalyst or a molecular sieve catalyst, wherein the active component of the molecular sieve catalyst is selected from the group containing or not containing rare earth and/or Phosphorous Y-type or HY-type zeolite, ultra-stable Y-type zeolite containing or not containing rare earth and/or phosphorus, ZSM-5 series zeolite or one of high silica zeolite with five-membered ring structure, beta zeolite, ferrierite One or more types can also be obtained by upgrading with a further developed new type of fluidized catalytic reforming catalyst.

Claims (10)

1. A method for separating catalytic gasoline modified oil and gas, characterized in that: the separation process of modified oil and gas is: Step 1: The upgraded oil and gas are taken out from the catalytic cracking gasoline auxiliary riser or auxiliary reactor and then enter a simple fractionation tower. The catalyst washing and desuperheating section at the bottom is in countercurrent contact with the oil slurry from the original catalytic cracking unit, and the catalyst powder is washed and processed. Heat exchange, after the oil slurry heat exchange temperature rises, it is drawn from the bottom of the fractionation tower into the oil slurry steam generator to recover high-temperature heat, and then returns to the riser reactor of the original catalytic cracking unit; Step 2: The washed oil gas enters the rectification section of the fractionation tower upwards to separate diesel fraction, gasoline fraction and cracked gas. 2. A method for separating catalytic gasoline modified oil and gas, characterized in that: the separation process of modified oil and gas is: Step 1: The upgraded oil gas is led out from the catalytic cracking gasoline auxiliary riser or auxiliary reactor and then enters a simple washing tower, and conducts countercurrent contact with the oil slurry from the original catalytic cracking unit to exchange heat and wash the catalyst powder, and the oil slurry enters the steam generator To recover high-temperature heat, and then return to the riser reactor of the original catalytic cracking unit; Step 2: The washed oil gas enters the steam generator to recover the high-temperature potential heat of the upgraded oil gas, and finally enters a simple fractionation tower to separate diesel fraction, gasoline fraction and cracked gas. 3. The method for separating catalytic gasoline modified oil and gas according to claim 1 or 2, characterized in that: the conditions of the modified oil and gas separation process are: Tower top temperature: 80-120°C; Diesel fraction extraction temperature: 170-250°C; Tower top pressure: 0.08 ~ 0.12Mpa gauge pressure. 4. The separation method of catalytic gasoline modified oil and gas according to claim 1 or 2, characterized in that: said modified oil and gas at least include the whole fraction of naphtha in catalytic cracking unit or the naphtha whose distillation range is greater than 60°C The distillate or naphtha light fraction with a distillation range less than 110°C is obtained by catalytic upgrading. 5. The method for separating catalytic gasoline modified oil and gas according to claim 1 or 2, characterized in that: the catalyst includes any catalyst in the catalytic cracking process, which is an amorphous silica-alumina catalyst or a molecular sieve catalyst or a fluidized catalyst Modified catalyst. 6. The separation method for catalytic gasoline modified oil and gas according to claim 1 or 2, characterized in that: the separated cracked gas enters the inlet of the gas-enriched compressor of the original catalytic cracking unit, and the separated gasoline fraction enters the original catalytic cracking unit The absorption and stabilization system of the device, the separated diesel fraction is removed from the gasoline stabilization tower of the absorption and stabilization system of the catalytic cracking unit as an absorbent. 7. A separation device for catalytic gasoline reforming oil and gas, characterized in that the device includes: the top of an auxiliary riser or auxiliary reactor is connected to the bottom of a simple fractionation tower; wherein, the bottom of the simple fractionation tower is connected to the oil slurry in sequence pump, oil slurry steam generator and heat exchanger, the middle part of the fractionation tower is connected with a diesel pump, and the top of the fractionation tower is connected with an oil-gas condenser and an oil-gas separation tank in turn. 8. A separation device for catalytic gasoline reforming oil and gas, characterized in that the device includes: the top of an auxiliary riser or auxiliary reactor is connected to the bottom of a simple washing tower; wherein, the bottom of the washing tower is connected to the oil slurry pump in turn And the oil slurry steam generator, the top of the washing tower is connected to the simple fractionation tower through the steam generator; the bottom of the simple separation tower is connected to the diesel pump, and the top is connected to the oil-gas condenser and the oil-gas separation tank in turn. 9. The separation device for catalytic gasoline reforming oil and gas according to claim 7, characterized in that: the simple fractionation tower is provided with 5-30 layers of trays, and the bottom of the fractionation tower is also equipped with catalyst washing and desuperheating segment, which has 3-10 layers of herringbone baffles. 10. The separation device for catalytic gasoline modified oil and gas according to claim 8, characterized in that: the simple washing tower is provided with 2-10 layers of herringbone baffles; the simple fractionating tower is provided with 5- 30 trays.

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