CN107739628A - A kind of method by dilute ethylene recovery various ingredients - Google Patents

Abstract

The present invention relates to a kind of method by dilute ethylene recovery various ingredients, in turn include the following steps：Containing the catalytic cracked dry gas that ethylene concentration is 15 ~ 25V% after washing, removing remaining monoethanolamine makes the ammonia-nitrogen content in raw material dry gas be less than 100ppm, cold dry gas is after First Heat Exchanger tentatively preheats, continue to preheat by the second heat exchanger, enter back into raw materials furnace and heating and be heated to reaction triggering temperature, reaction generation fuel oil ingredient and liquefied petroleum gas components into catalytic reactor；Reaction product enters the second heat exchanger and carries out secondary preheating to raw material dry gas, reaction product after cooling is fractionated, the heavy fuel oil ingredient fractionated out is extracted from the bottom of towe of fractionating column, is delivered in heavy fuel oil tank and stored with oil pump after the cooling of the first cooler；The oil-gas component fractionated out is steamed from the fractionating column gaseous phase outlet at the top of fractionating column, and the hot side into First Heat Exchanger is once preheated to raw material dry gas.This method can directly reclaim the components such as fuel oil ingredient, liquefied petroleum gas.

Description

A kind of method by dilute ethylene recovery various ingredients

Technical field

The present invention relates to a kind of method by dilute ethylene recovery various ingredients, belong to oil refining process technical field.

Background technology

Catalytic cracking is one of main method of oil secondary operation.Make heavy fry dried food ingredients in the presence of high temperature and catalyst Raw cracking reaction, it is changed into the process of cracked gas, gasoline and diesel oil etc..Key reaction has decomposition, isomerization, hydrogen migration, aromatization Change, condensation, green coke etc..Compared with thermal cracking, its lightweight oily yield is high, and octane number is high, and diesel oil stability is preferable, and by-product Liquefied gas rich in alkene.

The dry gas yied of existing catalytic cracking unit is 2 ~ 5%, contains the components such as hydrogen, ethene, methane, ethane in dry gas, Wherein ethylene concentration is 15 ~ 25V%.In middle-size and small-size refinery, the dry gas of catalytic cracking unit enters combustion gas generally as fuel gas Pipe network, for each unit furnace, boiler as fuel, residual fuel gas is then sent into flare system burn-up, causes ethene resource Waste, while also pollute environment.

The content of the invention

It is an object of the present invention to overcome problems of the prior art, there is provided a kind of by a variety of groups of dilute ethylene recovery The method divided, can directly generate fuel oil ingredient, liquefied petroleum gas components.

To solve above technical problem, a kind of method by dilute ethylene recovery various ingredients of the invention, include successively such as Lower step：Containing the catalytic cracked dry gas that ethylene concentration is 15 ~ 25V% after water washing tank V1 washings, taken off into amine liquid absorber V2 Except remaining monoethanolamine, the ammonia-nitrogen content in raw material dry gas is less than 100ppm, enter back into raw material surge tank V3, raw material buffering The cold dry gas of tank V3 outlets is tentatively preheated to 60 DEG C by First Heat Exchanger H1, continue through the second heat exchanger H2 be preheated to 90 ~ 100 DEG C, enter back into raw materials furnace and heating F1 and be heated to reaction triggering temperature, subsequently into passing through catalytic reaction in catalytic reactor R1 Generate fuel oil ingredient and liquefied petroleum gas components；Catalytic reactor reaction product is discharged from catalytic reactor R1 bottom, is entered The hot side for entering the second heat exchanger H2 carries out secondary preheating to the raw material dry gas by once preheating, and the catalytic reactor after cooling is anti- Answer product to enter in fractionating column T1 to be fractionated, the heavy fuel oil ingredient from the fractionating column T1 that fractionate out bottom of towe are extracted, warp First cooler L1 is cooled to 40 DEG C, is delivered in heavy fuel oil tank E1 and stored with heavy fuel oil pump P1；The oil fractionated out Gas component steams from the fractionating column gaseous phase outlet T1d at the top of fractionating column, and the hot side into First Heat Exchanger H1 is entered to raw material dry gas Row once preheats.

Relative to prior art, the present invention achieves following beneficial effect：In catalytic cracked dry gas containing hydrogen, ethene, The components such as methane, ethane, wherein ethylene concentration are 15 ~ 25V%, and 0.5MPa, the catalytic cracked dry gas of normal temperature are from catalytic cracked dry gas Pipe G1 is introduced into water washing tank V1 and washed, slightly the impurity such as de- monoethanolamine, subsequently into further being taken off in amine liquid absorber V2 Except remaining monoethanolamine, after the ammonia-nitrogen content in raw material dry gas is less than 100ppm, into raw material surge tank V3, raw material buffers The cold dry gas of tank V3 outlets is tentatively preheated to 60 DEG C by First Heat Exchanger H1, then continues to be preheated to 90 by the second heat exchanger H2 ~ 100 DEG C, reaction 240~280 DEG C of temperature of triggering is heated into raw materials furnace and heating F1, with the gradual intensification of reaction depth, heating Heater outlet temperature is improved to 260~350 DEG C and stably.Hot drying gas enter catalytic reactor R1 from the hot drying gas entrance R1a at top In, the temperature in catalytic reactor R1 is maintained at 260~380 DEG C, and pressure is maintained at 0.48MPa, and the ethene in hot drying gas is being urged The reaction such as overlapping, cyclisation, dehydrogenation, hydrogen migration and isomerization occurs under agent effect in catalytic reactor R1, directly generates combustion Expect oil ingredient and liquefied petroleum gas components.380 DEG C of catalytic reactor reaction products are discharged from catalytic reactor R1 bottom, are entered Second heat exchanger H2 hot side, secondary preheating is carried out to the raw material dry gas by once preheating using the heat of reaction product, both Raw materials furnace and heating F1 load is reduced, reduces its energy resource consumption, causes fuel oil ingredient and the liquefaction of catalytic reaction generation again The temperature of petroleum gas components is down to 245 DEG C, is fractionated into fractionating column T1, and fractionating column T1 tower top pressure is controlled in 0.45MPa, point Evaporate tower T1 tower top temperature control at 125 DEG C, fractionating column T1 column bottom temperature control at 225 DEG C, heavy fuel oil ingredient from point The bottom of towe for evaporating tower T1 is extracted, and 40 DEG C are cooled to through the first cooler L1, is forced into 0.5MPa with heavy fuel oil pump P1, is delivered to Heavy fuel oil tank E1 is stored, the first product after resulting in ethylene reaction and separating.120 DEG C of oil-gas component from Fractionating column gaseous phase outlet T1d at the top of fractionating column T1 is steamed, and into First Heat Exchanger H1 hot side, utilizes the heat of oil-gas component The raw material dry gas of normal temperature is once preheated, further reduces raw materials furnace and heating F1 load.The present invention utilizes 120 DEG C of oil Gas component is once preheated to raw material dry gas, then carries out secondary preheating to raw material dry gas using 380 DEG C of reaction product, real The raw material dry gas and the higher oil-gas component of temperature for having showed lowest temperature exchange heat, and the raw material dry gas after once preheating and temperature are higher Reaction product exchanges heat, and overall is in countercurrent flow form, takes full advantage of the gradient difference of temperature, two-stage heat exchange is all maintained higher Efficiency.

As the improvement of the present invention, the oil-gas component temperature discharged from First Heat Exchanger H1 hot side drops to 80 DEG C, so 40 DEG C are cooled into the second cooler L2 afterwards, the middle part for entering back into oil water separator V4 carries out three phase separation using density contrast, The sewage of oil water separator V4 bottoms is sent to sewage disposal system W1 processing by sewage pump P3；Light Fuel oil ingredient is in profit point From assembling in device V4, separating, discharged from oil water separator V4 bottom, then sent out by light Fuel oil pump P2, a part of lightweight Fuel oil ingredient enters fractionating column T1 as fractionating column T1 overhead reflux from fractionator overhead refluxing opening T1c, and another part is sent Stored to light Fuel oil tank E2.From the oil-gas component that fractionating column gaseous phase outlet T1d is steamed First Heat Exchanger H1 hot side Raw material dry gas is carried out after once preheating, temperature drops to 80 DEG C, then 40 DEG C is cooled to through the second cooler L2, into profit Three phase separation is carried out in the middle part of separator V4, had both reclaimed the heat that fractionating column steams oil-gas component, reduces the second cooler L2's Load, and raw material dry gas is once preheated, reduce raw materials furnace and heating F1 energy consumption.The light Fuel oil ingredient one isolated Overhead reflux of the part as fractionating column T1, is accurately controlled in 125 DEG C, another part is delivered to gently by fractionating column T1 tower top temperature Matter fuel oil service tank E2 is stored, second of product after resulting in ethylene reaction and separating.

As a further improvement on the present invention, the lean gas of discharge buffers through lean gas surge tank V5 at the top of oil water separator V4 Enter the first compressor C1 afterwards to compress, lean gas is pressurized to 0.6MPa by the first compressor C1, then through the 3rd cooler L3 with following Ring is water-cooled to 40 DEG C, enters back into a small amount of light-weight fuel oil for trapping in oil-trap V6 and being carried in lean gas, the lightweight combustion being captured Material oil is discharged from the light Fuel oil export V6b of oil-trap V6 bottoms, and is back to profit point from oil water separator refluxing opening V4d Oil phase space from device V4；Part lean gas of discharge at the top of oil-trap V6 passes through lean gas return valve U1 and lean gas return duct G3 After being mixed with the raw material dry gas of amine liquid absorber V2 outlets, enter raw material surge tank V3 jointly, will enter catalytic reactor R1's Ethylene concentration is controlled 10~20%.Because moisture content is extremely low in the light-weight fuel oil of oil-trap V6 trappings, oil water separator V4's Oil water separator refluxing opening V4d is located between oil water separator entrance V4a and light Fuel oil export V4b so that oil-trap V6 The light-weight fuel oil of trapping is directly entered oil water separator V4 oil phase space, is directly sent out or returned by light Fuel oil pump P2 Stream.The lean gas of part discharge at the top of oil-trap V6 is flowed back by lean gas return valve U1, will enter catalytic reactor R1 second Alkene concentration is controlled in suitable scope, can be compensated the fluctuation of concentration of unstripped gas, be ensured the stable operation of recovery system.

As a further improvement on the present invention, another part lean gas of discharge at the top of oil-trap V6 passes through lean gas drain valve U2 enters liquefied petroleum gas separating system, first passes through drop and impurity that coalescing filter Y1 removes deentrainment, then preheated device H4 is preheated to 40~50 DEG C, and one-level permeability and separation is carried out subsequently into one-level seperation film group X1, one-level seperation film group X1 discharges One-level tail gas enters the second-order separation film group X2 and carries out two level permeability and separation, and the two level tail gas from the second-order separation film group X2 discharges is Poor light hydrocarbon component delivers to gas ductwork E3 as fuel.The lean gas discharged from oil-trap exhaust outlet V6c is after impurity elimination, preheated device H4 is preheated to 40~50 DEG C and enters seperation film group so that propane, propylene, butane, butylene etc. can vaporize, and avoid liquid phase substance from gluing The surface of seperation film is connected on, to improve osmotic effect, it is ensured that poor light hydrocarbon component is completely separated out, the third production as system Product, it is sent to gas ductwork E3 and is used as fuel.

As a further improvement on the present invention, it is rich in gently from what one-level seperation film group X1 and the second-order separation film group X2 were penetrated The infiltration atmospheric pressure of hydrocarbon is 0.05MPa, respectively enters infiltration gas surge tank V7, then by the second compressor C2 pressure-raisings to 1.0MPa As liquid, into compressed gas surge tank V8 it is temporary after, into diesel oil absorption tower T2 bottom, 40 entered with absorbing tower jacking DEG C diesel oil counter current contacting, diesel oil absorb the liquefied petroleum gas components in infiltration gas during flowing downward, bottom of towe is rich in liquefaction stone The desorber entrance T3a that 42 DEG C of diesel oil of oil-gas component are sent into the middle part of desorber T3 carries out spray desorption, liquefied petroleum gas components From the desorber gaseous phase outlet T3c discharges at the top of desorber T3,40 DEG C are cooled to through the 4th cooler L4, into liquefied petroleum gas Surge tank V9 is kept in, and is extracted out by liquefied petroleum gas pump P4 and is boosted to 1.2MPa, a part is sent to liquefied petroleum gas storage tank E4 Storage.Infiltration gas rich in lighter hydrocarbons turns into liquid by the second compressor C2 pressure-raisings, inverse with 40 DEG C of diesel oil into diesel oil absorption tower T2 Stream contact can be such that the liquefied petroleum gas components in infiltration gas are fully absorbed by diesel oil, and the diesel oil rich in liquefied petroleum gas components is sent Enter desorber T3 desorptions, liquefied petroleum gas components are separated out, and after the 4th cooler L4 coolings, a part is sent to liquefaction stone Oil gas storage tank E4 is stored, and resulting in the 4th kind of product.

As a further improvement on the present invention, another part liquefied petroleum gas components backflow that liquefied petroleum gas pump P4 is sent out Tower top to desorber T3 is sprayed, and desorber T3 tower top temperature is controlled at 50 DEG C；Desorber bottom is provided with reboiler, weight Boil device using 0.3MPa steam as thermal source by the temperature control at desorber bottom at 102 DEG C, from desorber bottom discharge diesel oil by Diesel pump P5 is sent into the 3rd heat exchanger H3 hot side, and indirect heat exchange is carried out with the rich diesel oil of cold side, from absorb the bottom of the tower discharge The desorber entrance T3a that rich diesel oil enters in the middle part of desorber T3 after the 3rd heat exchanger H3 preheatings, from the 3rd heat exchanger H3 hot sides The absorption tower refluxing opening T2d that the diesel oil of discharge enters diesel oil absorption tower T2 tower tops is sprayed, and controls diesel oil absorption tower T2 tower top Temperature is 40 DEG C.Liquefied petroleum gas components are boosted to 1.2MPa and partly from desorber refluxing opening T3d by liquefied petroleum gas pump P4 The tower top for being back to desorber T3 is sprayed, and realizes recycling；The high temperature diesel oil of desorber T3 bottoms discharge and absorption tower The low temperature diesel oil of bottom discharge carries out indirect heat exchange, on the one hand reclaims the heat in hot side high temperature diesel oil, improves and enter into desorber The temperature of mouth T3a rich diesel oil, reduce desorber T3 energy consumption；On the other hand the bavin of desorber diesel oil outlet T3b discharges is caused Oil is able to overhead reflux as diesel oil absorption tower T2 after cooling, while recycling, ensures in the T2 of diesel oil absorption tower Assimilation effect.

As a further improvement on the present invention, do not absorbed in the T2 of diesel oil absorption tower by the residual gas that diesel oil absorbs from diesel oil Absorption tower gaseous phase outlet T2c discharges at the top of tower T2, are used into gas ductwork E3 as fuel.In the T2 of diesel oil absorption tower not by The residual gas that diesel oil absorbs also serves as the third fuel product separated, thus achieve resource all of real The zero-emission of pollutant is showed.

As a further improvement on the present invention, ethylene concentration detection is installed on the outlet conduit of the raw material surge tank V3 Instrument S1, the lean gas return valve U1 aperture are controlled by the ethylene concentration value that the ethylene concentration survey meter S1 is detected.According to The aperture for the ethylene concentration value control lean gas return valve U1 that ethylene concentration survey meter S1 is detected, by raw material surge tank V3 outlets Ethylene concentration control ensures the stable operation of whole dry-gas recovery system 10~20%.

As a further improvement on the present invention, each cooler is provided with cold using cooling water as medium, cooling water system But tower T4, cooling tower T4 are connected with cooling tower upper hose G7 and cooling tower downcomer G8, from the low of cooling tower downcomer G8 outflows Warm cooling water is introduced into the 3rd cooler L3 and the lean gas compressed through the first compressor C1 is cooled down, by lean gas temperature by 100 DEG C 40 DEG C are down to, the cooling water temperature discharged from the 3rd cooler L3 coolant outlet is 75 DEG C, into preheater H4 heat Side, the preheated device H4 of convection current lean gas are preheated, and lean gas is preheated into 40~50 DEG C enters one-level seperation film group X1 progress one Level permeability and separation.The preheated device H4 of heat convection contained using the high-temperature cooling water lean gas is preheated, and lean gas is preheated Enter one-level seperation film group X1 to 40~50 DEG C and carry out one-level permeability and separation, both realize the UTILIZATION OF VESIDUAL HEAT IN of high-temperature cooling water, again The load of cooling tower is reduced, while the lean gas to entering seperation film is preheated, and improves the effect of permeability and separation, and reduce The energy consumption of whole system.

As a further improvement on the present invention, the catalytic reactor R1 is sequentially provided with the first conversion zone, from top to bottom Two conversion zones and the 3rd conversion zone, the first cold dry gas entrance R1c, the second reaction are provided between the first conversion zone and the second conversion zone The second cold dry gas entrance R1d is provided between the conversion zones of Duan Yu tri-, the cold dry gas of raw material surge tank V3 outlets is respectively connected to first The cold cold dry gas entrance R1d of dry gas entrance R1c and second.Catalytic reactor R1 sets three conversion zones from top to bottom, can make to do Catalytic reaction thoroughly occurs for ethene in gas；Because catalytic reaction is exothermic reaction, if can only be at catalytic reactor R1 top Temperature control is carried out, with flowing downward for unstripped gas, the temperature of the first to the 3rd conversion zone can produce very big difference, unfavorable Stable in reaction is carried out, and between first and second conversion zone, the cold dry gas of raw material is passed through between second and third conversion zone, can be adjusted Each section of reaction temperature in catalytic reactor R1, prevents catalytic reactor R1 from temperature runaway occur.

Brief description of the drawings

The present invention is further detailed explanation with reference to the accompanying drawings and detailed description, accompanying drawing only provide with reference to Illustrate to use, be not used to the limitation present invention.

Fig. 1 is the flow chart of the embodiment of the method one of the invention by dilute ethylene recovery various ingredients.

Fig. 2 is the afterheat utilizing system figure of the 3rd heat exchanger cooling water in Fig. 1.

Fig. 3 is the flow chart of the embodiment of the method two of the invention by dilute ethylene recovery various ingredients.

Fig. 4 is the flow chart of the embodiment of the method three of the invention by dilute ethylene recovery various ingredients.

In figure：V1. water washing tank；V2. amine liquid absorber；V3. raw material surge tank；V4. oil water separator；V5. lean gas buffers Tank；V6. oil-trap；V7. gas surge tank is permeated；V8. compressed gas surge tank；V9. liquefied petroleum gas surge tank；R1. catalytic reaction Device；R1a. hot drying gas entrance；R1b. reactant exit；R1c. the first cold dry gas entrance；R1d. the second cold dry gas entrance；F1. it is former Expect heating furnace；H1. First Heat Exchanger；H2. the second heat exchanger；H3. the 3rd heat exchanger；H4. preheater；T1. fractionating column；T1a. mix Charge-coupled subentry；T1b. heavy fuel oil export；T1c. fractionator overhead refluxing opening；T1d. fractionating column gaseous phase outlet；T2. diesel oil Absorption tower；T2a. absorption tower infiltration gas entrance；T2b. absorption tower exports；T2c. absorption tower gaseous phase outlet；T2d. absorption tower is flowed back Mouthful；T3. desorber；T3a. desorber entrance；T3b. desorber diesel oil exports；T3c. desorber gaseous phase outlet；T3d. desorber Refluxing opening；T4. cooling tower；Y1. coalescing filter；L1. the first cooler；L2. the second cooler；L3. the 3rd cooler； L4. the 4th cooler；C1. the first compressor；C2. the second compressor；P1. heavy fuel oil pump；P2. light Fuel oil pump；P3. Sewage pump；P4. liquefied petroleum gas pump；P5. diesel pump；P6. cooling water circulating pump；X1. one-level seperation film group；X2. the second-order separation Film group；G1. raw material feed channel；G2. cold dry gas three-way pipeline；G3. lean gas return duct；G4. gas pipeline；G5. liquefied petroleum gas Return duct；G6. diesel return pipe；G7. cooling tower upper hose；G8. cooling tower downcomer；E1. heavy fuel oil tank；E2. it is light Matter fuel oil service tank；E3. gas ductwork；E4. liquefied petroleum gas storage tank；W1. sewage disposal system；U1. lean gas return valve；U2. Lean gas drain valve；S1. ethylene concentration survey meter.

Embodiment

As shown in figure 1, the present invention by dilute ethylene recovery various ingredients used by system include go out with catalytic cracked dry gas The catalytic cracked dry gas pipe G1 that mouth is connected, catalytic cracked dry gas pipe G1 outlet are connected with water washing tank V1 entrance, water washing tank V1 outlet is connected with amine liquid absorber V2 entrance, and amine liquid absorber V2 outlet is connected with raw material surge tank V3 entrance, Raw material surge tank V3 outlet is connected with cold dry gas three-way pipeline G2, cold dry gas three-way pipeline G2 upper port and First Heat Exchanger H1 cold side input port connection, First Heat Exchanger H1 cold side outlet port are connected with the second heat exchanger H2 cold side input port, the second heat exchange Device H2 cold side outlet port is connected with raw materials furnace and heating F1 entrance, raw materials furnace and heating F1 outlet with the top of catalytic reactor R1 Hot drying gas entrance R1a is connected, and the reactant exit R1b of catalytic reactor R1 bottoms and the second heat exchanger H2 hot side entrance connect Connect, the second heat exchanger H2 hot side outlet is connected with the blending ingredients entrance T1a of fractionating column T1 bottoms, point at the top of fractionating column T1 Evaporate tower gaseous phase outlet T1d to be connected with First Heat Exchanger H1 hot side entrance, the heavy fuel oil export T1b warps of fractionating column T1 bottoms First cooler L1 is connected with heavy fuel oil pump P1 entrance, heavy fuel oil pump P1 outlet and heavy fuel oil tank E1 It is connected.

Catalytic reactor R1 is sequentially provided with the first conversion zone, the second conversion zone and the 3rd conversion zone from top to bottom, and first is anti- Answer and the first cold dry gas entrance R1c is provided between section and the second conversion zone, second is provided between the second conversion zone and the 3rd conversion zone Cold dry gas entrance R1d, the first cold cold dry gas entrance R1d of dry gas entrance R1c and second are respectively under cold dry gas three-way pipeline G2 Port is connected.

First Heat Exchanger H1 hot side outlet is connected with the second cooler L2 entrance, the second cooler L2 outlet and oil Oil water separator entrance V4a in the middle part of separator V4 is connected, the light Fuel oil export V4b of oil water separator V4 bottoms with it is light Matter fuel pump P2 entrance is connected, and light Fuel oil pump P2 outlet is respectively with light Fuel oil tank E2's and fractionating column T1 Fractionator overhead refluxing opening T1c is connected；Oil water separator V4 bottom discharge mouth V4c passes through sewage pump P3 and sewage disposal system W1 is connected.

Oil water separator V4 top lean gas outlet V4c is connected with lean gas surge tank V5 lower entrances, lean gas surge tank V5 top exit is connected with the first compressor C1 entrance, and oil by the 3rd cooler L3 and is caught in the first compressor C1 outlet The oil-trap entrance V6a on device V6 tops is connected, light Fuel oil export V6b and oil water separator the V4 bottom of oil-trap V6 bottoms Oil water separator refluxing opening V4d be connected, oil water separator refluxing opening V4d is located at oil water separator entrance V4a in short transverse Between light Fuel oil export V4b；Oil-trap exhaust outlet V6c at the top of oil-trap V6 is returned by lean gas return valve U1 and lean gas Flow tube G3 is connected, and lean gas return duct G3 outlet is connected with raw material surge tank V3 entrance.

Oil-trap exhaust outlet V6c at the top of oil-trap V6 also passes through lean gas drain valve U2 and coalescing filter Y1 entrance It is connected, the coalescing filter Y1 preheated device H4 in outlet is connected with one-level seperation film group X1 entrance, one-level seperation film group X1 The one-level offgas outlet X1a at top is connected with the second-order separation film group X2 entrance, the second-order separation film group X2 two level offgas outlet X2a is connected by gas pipeline G4 with gas ductwork E3.

The two level that one-level seperation film group X1 one-level oozes vent outlet X1b and the second-order separation film group X2 oozes vent outlet X2b It is connected respectively with permeating gas surge tank V7 entrance, infiltration gas surge tank V7 outlet is connected with the second compressor C2 entrance, Second compressor C2 outlet is connected with compressed gas surge tank V8 entrance, compressed gas surge tank V8 outlet and diesel oil absorption tower The absorption tower infiltration gas entrance T2a of T2 bottoms is connected, in the middle part of the absorption tower outlet T2b and desorber T3 of diesel oil absorption tower T2 bottoms Desorber entrance T3a be connected, the desorber gaseous phase outlet T3c at the top of desorber T3 passes through the 4th cooler L4 and liquefied petroleum Gas surge tank V9 entrance is connected, and liquefied petroleum gas surge tank V9 outlet is connected with liquefied petroleum gas pump P4 entrance, liquefaction Petroleum gas pump P4 outlet is connected with liquefied petroleum gas storage tank E4.

Liquefied petroleum gas pump P4 outlet is also returned by the desorber of liquefied petroleum gas return duct G5 and desorber T3 tower tops Head piece T3d is connected；Desorber T3 bottoms are provided with reboiler, the desorber diesel oil outlet T3b and diesel pump P5's of desorber T3 bottoms Entrance is connected, and diesel pump P5 outlet is connected with diesel return pipe G6, and diesel return pipe G6 outlet is with the 3rd heat exchanger H3's Hot side entrance is connected, and the 3rd heat exchanger H3 hot side outlet is connected with the absorption tower refluxing opening T2d of diesel oil absorption tower T2 tower tops；Bavin The absorption tower outlet T2b of oil-absorption tower T2 bottoms is connected with the 3rd heat exchanger H3 cold side input port, the 3rd heat exchanger H3 cold side Outlet is connected with the desorber entrance T3a in the middle part of desorber T3.

Absorption tower gaseous phase outlet T2c at the top of the T2 of diesel oil absorption tower is connected by gas pipeline G4 with gas ductwork E3.

Containing components such as hydrogen, ethene, methane, ethane in catalytic cracked dry gas, wherein ethylene concentration is 15 ~ 25V%, 0.5MPa, the catalytic cracked dry gas of normal temperature are introduced into water washing tank V1 from catalytic cracked dry gas pipe G1 and washed, and slightly take off ethanol The impurity such as amine, subsequently into remaining monoethanolamine is further removed in amine liquid absorber V2, make the ammonia-nitrogen content in raw material dry gas After 100ppm, into raw material surge tank V3, the cold dry gas of raw material surge tank V3 outlets is preliminary by First Heat Exchanger H1 60 DEG C are preheated to, then continues to be preheated to 90 ~ 100 DEG C by the second heat exchanger H2, being heated to reaction into raw materials furnace and heating F1 touches 240~280 DEG C of temperature is sent out, with the gradual intensification of reaction depth, furnace outlet temperature is improved to 260~350 DEG C and stably.Heat Dry gas enters in catalytic reactor R1 from the hot drying gas entrance R1a at top, and the temperature in catalytic reactor R1 is maintained at 260~ 380 DEG C, pressure is maintained at 0.48MPa, the ethene in hot drying gas occur under catalyst action in catalytic reactor R1 overlapping, Cyclisation, dehydrogenation, hydrogen migration and isomerization etc. are reacted, and directly generate fuel oil ingredient and liquefied petroleum gas components.

380 DEG C of catalytic reactor reaction products are discharged from catalytic reactor R1 bottom, into the second heat exchanger H2 heat Side, using the heat of reaction product to carrying out secondary preheating by the raw material dry gas once preheated, both reduce raw materials furnace and heating F1 load, its energy resource consumption is reduced, cause the fuel oil ingredient of catalytic reaction generation and the temperature of liquefied petroleum gas components again 245 DEG C are down to, is fractionated into fractionating column T1, fractionating column T1 tower top pressure is controlled in 0.45MPa, fractionating column T1 tower top temperature Control is at 125 DEG C, and fractionating column T1 column bottom temperature is controlled at 225 DEG C, and heavy fuel oil ingredient is taken out from fractionating column T1 bottom of towe Go out, 40 DEG C are cooled to through the first cooler L1, be forced into 0.5MPa with heavy fuel oil pump P1, deliver to heavy fuel oil tank E1 Storage, the first product after resulting in ethylene reaction and separating.

120 DEG C of oil-gas component steams from the fractionating column gaseous phase outlet T1d at the top of fractionating column T1, into First Heat Exchanger H1 Hot side, the raw material dry gas of normal temperature is once preheated using the heat of oil-gas component, further reduces raw materials furnace and heating F1 Load.The present invention is once preheated using 120 DEG C of oil-gas component to raw material dry gas, is then produced using 380 DEG C of reaction Thing carries out secondary preheating to raw material dry gas, and the raw material dry gas and the higher oil-gas component of temperature for realizing lowest temperature exchange heat, once Raw material dry gas after preheating exchanges heat with the higher reaction product of temperature, and overall is in countercurrent flow form, takes full advantage of temperature Gradient difference, two-stage heat exchange is set all to maintain higher efficiency.

Catalytic reactor R1 sets three conversion zones from top to bottom, can make ethene in dry gas that catalytic reaction thoroughly occur； Because catalytic reaction is exothermic reaction, if temperature control can only be carried out at catalytic reactor R1 top, with unstripped gas Flowing downward, the temperature of the first to the 3rd conversion zone can produce very big difference, be unfavorable for the stable progress of reaction, first, Between two conversion zones, the cold dry gas of raw material is passed through between second and third conversion zone, each section in catalytic reactor R1 of reaction can be adjusted Temperature, prevent catalytic reactor R1 from temperature runaway occur.

Hot side from the oil-gas component that fractionating column gaseous phase outlet T1d is steamed in First Heat Exchanger H1 carries out one to raw material dry gas After secondary preheating, temperature drops to 80 DEG C, is then cooled to 40 DEG C through the second cooler L2, is utilized into oil water separator V4 middle parts Density contrast carries out three phase separation, and a small amount of sewage of oil water separator V4 bottoms is sent to sewage disposal system W1 by sewage pump P3 Reason, light Fuel oil ingredient are assembled in oil water separator V4, separated, and are discharged from oil water separator V4 bottom, then by lightweight Fuel pump P2 is sent out, a part of light Fuel oil ingredient as fractionating column T1 overhead reflux from fractionator overhead refluxing opening T1c enters fractionating column T1, fractionating column T1 tower top temperature is accurately controlled in into 125 DEG C, another part delivers to light-weight fuel oil storage Tank E2 is stored, second of product after resulting in ethylene reaction and separating.

Oil water separator V4 top lean gas enters the first compressor C1 after lean gas surge tank V5 bufferings and compressed, the first pressure Lean gas is pressurized to 0.6MPa by contracting machine C1, is then cooled with circulating water through the 3rd cooler L3 to 40 DEG C, from oil-trap entrance V6a Into in oil-trap V6, oil-trap V6 traps a small amount of light-weight fuel oil carried in lean gas, is fired from the lightweight of oil-trap V6 bottoms Expect oil export V6b discharges, and be back to from oil water separator refluxing opening V4d in oil water separator V4, because oil-trap V6 is trapped Light-weight fuel oil in moisture content it is extremely low, oil water separator V4 oil water separator refluxing opening V4d is located at oil water separator entrance Between V4a and light Fuel oil export V4b so that the light-weight fuel oil of oil-trap V6 trappings is directly entered oil water separator V4's Oil phase space, directly sent out or flowed back by light Fuel oil pump P2.Part lean gas of discharge at the top of oil-trap V6 passes through After lean gas return valve U1 and lean gas return duct G3 mixes with pretreated raw material dry gas, enter raw material surge tank V3 jointly, can The fluctuation of concentration of unstripped gas is compensated, ensures the stable operation of recovery system.

Ethylene concentration survey meter S1 is installed, lean gas return valve U1 aperture is controlled on raw material surge tank V3 outlet conduit In the ethylene concentration value that ethylene concentration survey meter S1 is detected.The ethylene concentration value control detected according to ethylene concentration survey meter S1 Lean gas return valve U1 processed aperture, by the ethylene concentration control of raw material surge tank V3 outlets 10~20%, ensure that whole dry gas returns The stable operation of receipts system.

Liquefied petroleum gas separating system is also entered by lean gas drain valve U2 from the lean gas of oil-trap exhaust outlet V6c discharges, Drop and impurity that coalescing filter Y1 removes deentrainment are first passed through, then preheated device H4 is preheated to 40~50 DEG C, into one-level Seperation film group X1 carries out one-level permeability and separation, enters the second-order separation film group X2 from the one-level tail gas of one-level offgas outlet X1a discharges Two level permeability and separation is carried out, is used as and separates from the poor light hydrocarbon component of two level tail gas of two level offgas outlet X2a discharges The third product, it is sent to gas ductwork E3 and is used as fuel.

The infiltration atmospheric pressure rich in lighter hydrocarbons that one-level seperation film group X1 and the second-order separation film group X2 are penetrated is 0.05MPa, Ooze vent outlet X1b from one-level and ooze vent outlet X2b with two level and respectively enter and permeate gas surge tank V7, then by the second compressor C2 Pressure-raising turns into liquid to 1.0MPa, after compressed gas surge tank V8 is temporary, permeates gas entrance T2a from absorption tower and is absorbed into diesel oil Tower T2 bottom, the 40 DEG C of diesel oil counter current contactings entered with absorbing tower jacking, diesel oil are absorbed during flowing downward in infiltration gas Liquefied petroleum gas components, the desorber entrance that 42 DEG C diesel oil of the bottom of towe rich in liquefied petroleum gas components are sent into the middle part of desorber T3 T3a carries out spray desorption, and liquefied petroleum gas components are cold through the 4th from the desorber gaseous phase outlet T3c discharges at the top of desorber T3 But device L4 is cooled to 40 DEG C, is kept in into liquefied petroleum gas surge tank V9, is extracted out and is boosted to by liquefied petroleum gas pump P4 1.2MPa, a part are sent to liquefied petroleum gas storage tank E4 storages as the 4th kind of product isolated.

Liquefied petroleum gas components are boosted to liquefied petroleum gas pump P4 into 1.2MPa and part is flowed back from desorber refluxing opening T3d Tower top to desorber T3 is sprayed, and is recycled, and desorber T3 tower top temperature is controlled at 50 DEG C.Desorber T3 bottoms Reboiler using 0.3MPa steam be used as thermal source, control desorber bottom temperature be 102 DEG C, diesel pump P5 boosts to 1.2MPa The 3rd heat exchanger H3 hot side is sent into, indirect heat exchange is carried out with the rich diesel oil of cold side, on the one hand reclaims the heat in hot side diesel oil, The temperature into desorber entrance T3a rich diesel oil is improved, desorber T3 energy consumption is reduced, on the other hand causes desorber diesel oil The diesel oil for exporting T3b discharges enters the absorption tower refluxing opening T2d of diesel oil absorption tower T2 tower tops after the 3rd heat exchanger H3 coolings, follows Ring use, and control diesel oil absorption tower T2 tower top temperature be 40 DEG C.

Do not gone out in the T2 of diesel oil absorption tower by the residual gas that diesel oil absorbs from the absorption tower gas phase at the top of the T2 of diesel oil absorption tower Mouth T2c discharges, also serve as the third product separated, are sent to gas ductwork E3 and are used as fuel, thus achieved Resource all of realizing the zero-emission of pollutant.

As shown in Fig. 2 each cooler is provided with cooling tower T4, cooling tower using cooling water as medium, cooling water system T4 is connected with cooling tower upper hose G7 and cooling tower downcomer G8；Cooling tower downcomer G8 outlet is cold with the 3rd cooler L3's But water inlet is connected, and the 3rd cooler L3 coolant outlet is connected with preheater H4 hot side import, preheater H4 hot side Outlet is connected with cooling water circulating pump P6 entrance, and cooling water circulating pump P6 outlet is connected with cooling tower upper hose G7.

The 3rd cooler L3 is introduced into being pressed through the first compressor C1 from the low-temperature cooling water of cooling tower downcomer G8 outflows The lean gas of contracting is cooled down, and lean gas temperature is down into 40 DEG C by 100 DEG C, is discharged from the 3rd cooler L3 coolant outlet cold But coolant-temperature gage is up to 75 DEG C, into preheater H4 hot side, the preheated device H4 of heat convection contained using the high-temperature cooling water Lean gas preheated, lean gas be preheated to 40~50 DEG C enter one-level seperation film group X1 and carry out one-level permeability and separations, both realized The UTILIZATION OF VESIDUAL HEAT IN of high-temperature cooling water, the load of cooling tower is again reduced, while the lean gas to entering seperation film is preheated, Reduce the energy consumption of whole system.

Fig. 3 show another embodiment of the present invention, and the cold dry gas of raw material surge tank V3 outlets is without the first heat exchange Device H1, only exchanged heat by the second heat exchanger H2.Remaining is identical with embodiment one.

Fig. 4 show another embodiment of the present invention, the 3rd heat exchanger H3 cold side not Fu Chai with absorption tower discharge Oil carries out indirect heat exchange, but is passed through cooling water and the diesel oil of desorber diesel oil outlet T3b discharges is cooled down, remaining and implementation Example one is identical.

It the foregoing is only the preferable possible embodiments of the present invention, non-therefore the limitation present invention patent protection model Enclose.In addition to the implementation, the present invention can also have other embodiment.All skills formed using equivalent substitution or equivalent transformation Art scheme, all falls within the protection domain of application claims.Technical characteristic of the invention without description can be by or using now There is technology realization, will not be repeated here.

Claims (10)

1. A kind of 1. method by dilute ethylene recovery various ingredients, it is characterised in that in turn include the following steps：It is containing ethylene concentration 15 ~ 25V% catalytic cracked dry gas is through water washing tank（V1）After washing, into amine liquid absorber（V2）The middle remaining monoethanolamine of removing, The ammonia-nitrogen content in raw material dry gas is less than 100ppm, enter back into raw material surge tank（V3）In, raw material surge tank（V3）Outlet Cold dry gas passes through First Heat Exchanger（H1）60 DEG C tentatively are preheated to, continues through the second heat exchanger（H2）90 ~ 100 DEG C are preheated to, Enter back into raw materials furnace and heating（F1）Reaction triggering temperature is heated to, subsequently into catalytic reactor（R1）In given birth to by catalytic reaction Into fuel oil ingredient and liquefied petroleum gas components；Catalytic reactor reaction product is from catalytic reactor（R1）Bottom discharge, enter Enter the second heat exchanger（H2）Hot side to carrying out secondary preheating, the catalytic reactor after cooling by the raw material dry gas that once preheats Reaction product enters fractionating column（T1）In be fractionated, the heavy fuel oil ingredient fractionated out is from fractionating column（T1）Bottom of towe taken out Go out, through the first cooler（L1）40 DEG C are cooled to, with heavy fuel oil pump（P1）Deliver to heavy fuel oil tank（E1）Middle storage； The oil-gas component fractionated out is from the fractionating column gaseous phase outlet at the top of fractionating column（T1d）Steam, into First Heat Exchanger（H1）Heat Side is once preheated to raw material dry gas.
2. 2. the method according to claim 1 by dilute ethylene recovery various ingredients, it is characterised in that：From First Heat Exchanger （H1）Hot side discharge oil-gas component temperature drop to 80 DEG C, subsequently into the second cooler（L2）40 DEG C are cooled to, then is entered Enter oil water separator（V4）Middle part utilize density contrast carry out three phase separation, oil water separator（V4）The sewage of bottom is by sewage pump （P3）It is sent to sewage disposal system（W1）Processing；Light Fuel oil ingredient is in oil water separator（V4）Middle aggregation, separation, from profit Separator（V4）Bottom discharge, then by light Fuel oil pump（P2）Send out, a part of light Fuel oil ingredient is as fractionating column （T1）Overhead reflux from fractionator overhead refluxing opening（T1c）Into fractionating column（T1）, another part deliver to light-weight fuel oil storage Tank（E2）Storage.
3. 3. the method according to claim 2 by dilute ethylene recovery various ingredients, it is characterised in that：From oil water separator （V4）The lean gas of top discharge is through lean gas surge tank（V5）Enter the first compressor after buffering（C1）Compression, the first compressor（C1） Lean gas is pressurized to 0.6MPa, then through the 3rd cooler（L3）It is cooled with circulating water to 40 DEG C, enters back into oil-trap（V6）In A small amount of light-weight fuel oil for carrying in trapping lean gas, the light-weight fuel oil being captured is from oil-trap（V6）The light-weight fuel oil of bottom Outlet（V6b）Discharge, and from oil water separator refluxing opening（V4d）It is back to oil water separator（V4）Oil phase space；A part From oil-trap（V6）The lean gas of top discharge passes through lean gas return valve（U1）And lean gas return duct（G3）With amine liquid absorber（V2） After the raw material dry gas mixing of outlet, enter raw material surge tank jointly（V3）, catalytic reactor will be entered（R1）Ethylene concentration control System is 10~20%.
4. 4. the method according to claim 3 by dilute ethylene recovery various ingredients, it is characterised in that：Another part is from catching oil Device（V6）The lean gas of top discharge passes through lean gas drain valve（U2）Into liquefied petroleum gas separating system, coagulation type filtering is first passed through Device（Y1）Except the drop and impurity of deentrainment, then preheated device（H4）40~50 DEG C are preheated to, subsequently into one-level seperation film group （X1）Carry out one-level permeability and separation, one-level seperation film group（X1）The one-level tail gas of discharge enters the second-order separation film group（X2）Carry out two Level permeability and separation, from the second-order separation film group（X2）The two level tail gas of discharge is that poor light hydrocarbon component delivers to gas ductwork（E3）As Fuel.
5. 5. the method according to claim 4 by dilute ethylene recovery various ingredients, it is characterised in that：From one-level seperation film group （X1）And the second-order separation film group（X2）The infiltration atmospheric pressure rich in lighter hydrocarbons penetrated is 0.05MPa, respectively enters infiltration gas and delays Rush tank（V7）, then by the second compressor（C2）Pressure-raising turns into liquid to 1.0MPa, into compressed gas surge tank（V8）After temporary, enter Enter diesel oil absorption tower（T2）Bottom, the 40 DEG C of diesel oil counter current contactings entered with absorbing tower jacking, during diesel oil flows downward The liquefied petroleum gas components in infiltration gas are absorbed, 42 DEG C diesel oil of the bottom of towe rich in liquefied petroleum gas components are sent into desorber（T3）In The desorber entrance in portion（T3a）Carry out spray desorption, liquefied petroleum gas components are from desorber（T3）The desorber gas phase at top goes out Mouthful（T3c）Discharge, through the 4th cooler（L4）40 DEG C are cooled to, into liquefied petroleum gas surge tank（V9）It is temporary, by liquefaction stone Oil gas pump（P4）Extract out and boost to 1.2MPa, a part is sent to liquefied petroleum gas storage tank（E4）Storage.
6. 6. the method according to claim 5 by dilute ethylene recovery various ingredients, it is characterised in that：Liquefied petroleum gas pump （P4）Another part liquefied petroleum gas components of submitting are back to desorber（T3）Tower top sprayed, by desorber（T3）'s Tower top temperature is controlled at 50 DEG C；Desorber bottom is provided with reboiler, and reboiler is using 0.3MPa steam as thermal source by desorber bottom Temperature control at 102 DEG C, from desorber bottom discharge diesel oil by diesel pump（P5）It is sent into the 3rd heat exchanger（H3）Hot side, with The rich diesel oil of cold side carries out indirect heat exchange, and the rich diesel oil discharged from absorb the bottom of the tower is through the 3rd heat exchanger（H3）Enter solution after preheating Inhale tower（T3）The desorber entrance at middle part（T3a）, from the 3rd heat exchanger（H3）The diesel oil of hot side discharge enters diesel oil absorption tower （T2）The absorption tower refluxing opening of tower top（T2d）Spray, and control diesel oil absorption tower（T2）Tower top temperature be 40 DEG C.
7. 7. the method according to claim 5 by dilute ethylene recovery various ingredients, it is characterised in that：Diesel oil absorption tower（T2） In the residual gas that is not absorbed by diesel oil from diesel oil absorption tower（T2）The absorption tower gaseous phase outlet at top（T2c）Discharge, into combustion Gas pipe network（E3）Used as fuel.
8. 8. the method according to claim 3 by dilute ethylene recovery various ingredients, it is characterised in that：The raw material surge tank （V3）Outlet conduit on ethylene concentration survey meter is installed（S1）, the lean gas return valve（U1）Aperture be controlled by the second Alkene concentration survey meter（S1）The ethylene concentration value detected.
9. 9. the method according to claim 4 by dilute ethylene recovery various ingredients, it is characterised in that：Each cooler uses Cooling water is provided with cooling tower as medium, cooling water system（T4）, cooling tower（T4）It is connected with cooling tower upper hose（G7）With it is cold But tower downcomer（G8）, from cooling tower downcomer（G8）The low-temperature cooling water of outflow is introduced into the 3rd cooler（L3）To through first Compressor（C1）The lean gas of compression is cooled down, and lean gas temperature is down into 40 DEG C by 100 DEG C, from the 3rd cooler（L3）Cooling The cooling water temperature of water out discharge is 75 DEG C, into preheater（H4）Hot side, the preheated device of convection current（H4）Lean gas carry out Preheating, lean gas is preheated to 40~50 DEG C and enters one-level seperation film group（X1）Carry out one-level permeability and separation.
10. 10. the method according to claim 1 by dilute ethylene recovery various ingredients, it is characterised in that：The catalytic reaction Device（R1）The first conversion zone, the second conversion zone and the 3rd conversion zone, the first conversion zone and the second reaction are sequentially provided with from top to bottom The first cold dry gas entrance is provided between section（R1c）, the second cold dry gas entrance is provided between the second conversion zone and the 3rd conversion zone （R1d）, raw material surge tank（V3）The cold dry gas of outlet is respectively connected to the first cold dry gas entrance（R1c）With the second cold dry gas entrance （R1d）.