CN1060754C - Regeneration and circulating utilization of HF-amine compound in HF alkylate - Google Patents

Abstract

In an alkylation method which uses HF-amine compounds, such as HF-pyridinium, as a catalytic system, the compounds are recovered for reuse from a by-product flow (10) by the following steps: step a. partial HF is selectively removed from the by-product flow (10) to generate a poor HF material flow (22) whose molar ratio of HF to coordination agents is from 3:1 to 5:1; step b. the generated poor HF material flow (22) is divided into rich ASO hydrocarbon phases and poor ASO acid phases (28) which contain most compounds; step c. the acid phases (28) are recycled to the step of hydrocarbon alkylation.

Description

The regeneration of HF-amine compound and recycle in the HF alkylation

The field of the invention is the hydrocarbon treatment process.The present invention relates in mixture, use liquid-fluorination hydrogen (HF)-Lewis base such as pyridine mixture, hydrocarbon is carried out catalytic alkylation.

Use the alkylation of HF to be widely used in commercial refining and petrochemical processing.Generally, alkylation is to add alkyl on another hydrocarbon.Commercial, use HF with propylene, butylene and pentene isomers to isobutane alkylation, produce the high octane gasoline blending component, and in washing composition is produced to benzene alkylation.

Known HF is extremely harmful material and chemical.Because the character that HF self holds, it needs special the processing.Consider the influence of HF, cause reduce HF unexpected release rapid evaporation and form the research of method of the possibility of deleterious HF cloud and mist as far as possible to healthy and environment.A kind of approach is that HF is cooperated with suitable compound, and the vapour pressure and the HF that reduce HF form aerocolloidal tendency.

Known some nitrogenous compound and HF form mixture and reduce its volatility, as pyridine, picoline, quinoline, Trimethylamine 99 and triethylamine.See JP-A-57 (1982)-92502.Olah discloses HF and the mixture of preferred nitrogenous compound (coordination agent) as ammonia, methylamine, ethamine, propylamine, butylamine, amylamine, pyridine, picoline, melamine and vulkacit H in US-A-5073674, it keeps effective catalytic activity at alkene in to the alkane alkylation.The preferred coordination agent of Olah and the mixture of HF are hereinafter referred to as the HF-amine compound.

In the alkylation of existing use HF, owing to add the expense of fresh coordination agent as a supplement, this HF-amine mixt is unsuitable for using economically.Art methods has the tendency of the coordination agent that concentrates in the logistics of discharging in operation from then on.This is because of ASO, or sour soluble oil may be dissolved in the HF-amine compound.ASO is a term recognized in the art, is sometimes referred to as the soluble oil of HF, polymkeric substance, mixed polymer or polymkeric substance by product.ASO dissolves in HF.In alkylation process, ASO is the alkylation by product, generally forms by the reaction of the impurity in reactant oligomerization or the alkylation operation charging.Therefore, according to the reactant of alkylation operation, operational condition etc., ASO can have a large amount of different composition and physical propertiess.In motor spirit alkylation operation and detergent alkylation equalization, all form ASO.The boiling spread of ASO can be 149-482 ℃ (300-900F).It also may contain other nonhydrocarbon element, comprises halogen, oxygen, nitrogen, sulphur etc.Known to the technician in the HF alkylation field, ASO generally lowers the HF activity of such catalysts.This is the effect under the ASO of relative lower concentration just, but under greater concn, it has comprehensive detrimental effect to this operation.Therefore, in those technologies that form ASO, must at least periodically remove ASO from round-robin HF, this operation is commonly referred to as regeneration.In typical HF alkylation operation, regeneration generally comprises distillation or stripping HF from HF and ASO logistics, and HF is returned the alkylation operation, discarded ASO.But because the boiling point of HF-amine compound is generally in the boiling spread of ASO.Coordination agent is discharged from operation with ASO, and the amount of coordination agent is consumed in the operation as a result.This causes or increases the volatility of circulation HF stream at last, and this may increase the danger of unexpected evaporation atomizing; Add fresh coordination agent as a supplement in operation, this is uneconomical again.Therefore, need a kind of method of from ASO, separating coordination agent, so that the coordination agent of separating can the recycling in this operation of efficient and cost-effective ground.

US-A-3959402 discloses the method that a kind of separation contains the logistics of ASO, dissolving HF and CBM or " constant boiling mixture ".CBM is the term of generally acknowledging in the alkylation field, refers to the constant boiling mixture of HF and water.This method comprises that first stripping is removed to small part HF, poorer HF logistics is separated into rich CBM mutually with rich ASO mutually.

US-A-5191150 discloses the method that a kind of separation contains the logistics of ASO, HF and tetramethylene sulfone, tells HF earlier, relends gravity poor HF logistics is divided into rich in polymers stream and rich tetramethylene sulfone stream.

US-A-5237122 discloses the method that a kind of separation contains HF and a kind of sulphones, adds entry earlier, and sedimentation goes out ASO phase and sulfone-water again.

The invention relates to the method that from the by product stream that contains ASO, HF and HF-amine compound, reclaims the HF-amine compound.This method is at first to remove section H F at least from incoming flow, forms poor HF stream, then poor HF stream is divided into the logistics of enrichment ASO and another logistics of enrichment HF-amine compound.This method is to remove the special effective means of ASO from such mixture, has used the preferred coordination agent of Lewis base such as Olah to form aerocolloidal tendency to reduce HF in the described mixture.

The present invention compares the method difference with surprising different performance and prior art with the mixture of HF and water with the mixture of HF and amine coordination agent.HF and the combination of pyridine and similar coordination agent and to combine the performance that produces thus be unique.But for example pyridine and water are very inequality, and it is dissolved in ASO, find that now some mixture of HF and pyridine makes us the same with HF water constant boiling mixture uncannily, they almost with the ASO unmixing.The present invention utilizes the surprising discovery about the mixture of HF and amine coordination agent such as pyridine, separates the HF-amine compound with the method for special efficient and cost-effective from ASO.Using HF and at least intermittently discharging in the technology of ASO, the present invention is used for separation before discarded ASO, recovery and recycle amine coordination agent.Therefore, the invention enables and to use pyridine and similar coordination agent to reduce to form the volatility of HF in the technology of ASO economically.

Therefore, in first kind of embodiment, the present invention is the method for removing ASO from the logistics that contains ASO, HF and HF-amine compound.In a disengaging zone, from logistics, optionally be removed to small part HF, with the mol ratio that produces HF and coordination agent 3: 1 to 5: 1 poor HF stream.In another disengaging zone, this poor HF stream is divided into the logistics of enrichment ASO and the logistics of enrichment HF-amine compound.

In second kind of embodiment, the present invention is the method for removing ASO from the incoming flow that contains ASO, HF and HF-pyridine mixture, and wherein ASO forms in the alkylation operation of the mixture through catalytic that contains HF and pyridine.At stripping zone, from incoming flow, optionally be removed to small part HF, with generation HF and pyridine mol ratio 3: 1 to 5: 1 poor HF stream.In phase separation region, this HF stream is divided into the logistics of enrichment ASO and the logistics of enrichment HF-pyridine mixture, and the latter returns the reaction zone of alkylation operation.

Fig. 1 is the general flowchart of embodiment of the present invention.

The incoming flow of this method contains amine complexant such as pyridine, HF and ASO. This mixture can also contain water. This incoming flow can produce from the HF alkylation operation of the mixture through catalytic that contains the HF-amine compound.

The suitable lewis base that can be used as complexant contains arbitrary 5A family element, i.e. nitrogen, phosphorus, arsenic, antimony and bismuth. HF-lewis base compound will have enough polarity, it not too is dissolved in is generally among the nonpolar ASO, can separate by being separated HF-lewis base compound and ASO like this. The polarity of HF-lewis base compound is larger, and separating between HF-lewis base compound and ASO is easier. In the element that forms 5A family, along with the molecular weight of element reduces, the polarity of corresponding lewis base generally increases, because along with molecular weight reduces, the circumnuclear electron cloud of the atom of element becomes more concentrated and still less disperses. So along with the molecular weight of 5A family element reduces, HF-lewis base compound will have enough polarity, make be separated easier. Therefore, preferably 5A family element has minimum molecular weight, i.e. nitrogen. Nitrogenous complexant can be: chemical formula NR₁R ₂R ₃One of, R wherein₁、R ₂And R₃Can be alkyl, aryl or hydrogen, comprise ammonia, methylamine, ethamine, propylamine, butylamine, amylamine, dimethylamine, trimethylamine, diethylamine, triethylamine, diphenylamines, dibenzylamine and aniline, and the aniline of alkyl and aryl replacement, comprise N, the N-dimethylaniline; Pyridine, and the pyridine, particularly methyl substituted pyridine of alkyl and aryl replacement comprise picoline, lutidines and collidine; Polycyclic compound is such as quinoline; The compound that contains an above nitrogen-atoms comprises non-ring compound such as ethylenediamine and cyclic compound such as imidazoles; In ring, be contained in the cyclic compound of other class atom, comprise morpholine. Preferred complexant is pyridine. Incoming flow can contain more than one complexants.

With the mixture of HF in, lewis base can cooperate with HF to some extent. The tendency that lewis base and HF form compound has been described in JP-A-57 (1982)-92502 and among the US-A-5073674. Although the degree that cooperates depends on the type of lewis base and the amount of its relative HF in mixture, the accurate fitness of lewis base and HF is uncertain. JP-A-5792502 points out that a Pyridine Molecules cooperates with 20 HF molecules under certain condition. As a kind of hypothesis, believe to cooperate more securely (as by intermolecular ionic forces) with lewis base neighbour's HF molecule, and cooperate (as passing through Van der Waals force) from the HF molecule of lewis base away from than loosely. JP-A-5792502 also is taught in the next Pyridine Molecules of certain condition and three HF molecules form stable compound. The mixture that contains HF and lewis base can be comprised of several HF-lewis base compounds, and every kind of lewis base molecules is had different HF molecule numbers. Therefore " HF-lewis base compound " is interpreted as referring to one or more HF-lewis base compounds. As a kind of hypothesis, believe that the fitness of lewis base and HF generally reduces along with the increase of 5A family element molecular weight. Therefore. The match ratio that HF will tend to nitrogenous lewis base is more extensive with cooperating of bismuth-containing lewis base. In any case, the actual degree that cooperates with HF of lewis base, depend on the actual HF-lewis base compound that exists the mixture from the be separated difficulty or ease of lewis base of ASO, rather than lewis base itself. In the present invention, the concentration of complexant is generally 1-50wt% without the ASO mixture in the incoming flow. HF concentration is generally the 50-99wt% without the ASO mixture in the incoming flow. The mol ratio of HF and complexant is general remarkable in 5: 1.

In these wide regions of Louis acid and HF concentration to specific lewis base have different more among a small circle. For any specific lewis base, it will depend on its physical property and its vapour pressure inhibition in alkylation from the concentration in the incoming flow of HF alkylation operation. For example, when lewis base was pyridine, the concentration of pyridine was generally the 5wt%-25wt% without the ASO mixture in the incoming flow. Be preferably 10wt%-20wt%. Therefore, for pyridine, the concentration of HF is generally the 75wt%-95wt% without the ASO mixture in the incoming flow, is preferably the about 90wt% of about 80wt%-.

Preferred pin of the present invention is to containing the logistics of amine coordination agent, HF and ASO, and most preferably the amine coordination agent is a pyridine.As the preferred embodiments of the invention, following explanation concentrates in the use of pyridine.

The specific composition of ASO is unimportant for operation of the present invention, and the present invention can be used for above-mentioned any suitable ASO.Be suitable for from containing ASO, the operational condition of the present invention of separating ASO in the mixture of HF and pyridine will depend on ASO.Need not too much test, those skilled in the art just can determine to be suitable for the operational condition that different ASO form.Meaning promptly is not limited to scope of the present invention any specific ASO and forms.The concentration of ASO is generally 0.5-25wt% in the incoming flow, but this is not a key element of the present invention.

In incoming flow, can there be water.In HF alkylation operation, water can enter operation with feed hydrocarbon, is dissolved in then among the HF, at last as HF and H ₂The constant boiling mixture of O is discharged.Along with water concentration among the HF increases, the HF-water mixture has more corrodibility.For anti-sealing collects tired and produces corrosion in the alkylation operation, generally from circulation HF, separate water outlet.Water concentration is generally the 0.1-3.0wt% of no ASO mixture in the incoming flow.

According to the present invention, at first remove the F of section H at least in the charging.The ad hoc approach of removing HF from charging is not a key character of the present invention.This method may be removed part pyridine, the effect of perhaps removing the pyridine that cooperates with HF from charging in addition from charging.But general method therefor is removed the ratio of HF greater than pyridine.Though the removal method can be flash distillation, distillation or extraction, the preferred method of removing HF from incoming mixture is a stripping.This scheme is stated in US-A-3249650, and the logistics that wherein will contain Trimethylmethane and other lighter hydrocarbons is introduced at the bottom of the stripping tower, and the technician in the alkylation field claims that generally this tower is regeneratory furnace or rerunning tower.Though regeneratory furnace can comprise flashing chamber or packed bed tower, is preferably tray column.Being used for isolating heat is provided by (stab-in) formula of thrusting in the regeneratory furnace or kettle-type reboiler, but preferably gives the stripping tower heat supply by the stripping medium, and it provides the big at least portion of input stripping tower, preferred net quantity of heat.In addition, charging can preheating.The stripping medium can be nitrogen, hydrogen, methane, ethane, propane or any other non-reactive gas.For the motor spirit alkylation process, the stripping medium can contain pentane, but it preferably contains heat or overheated Trimethylmethane.For the detergent alkylation metallization processes, the stripping medium can contain benzene, but does not preferably use the stripping medium.Operating this HF separating step, to contain HF and coordination agent mol ratio with generation be that 3: 1 to 5: 1 poor HF logistics is a key character.

In the bottoms of stripping tower, be called the logistics of poor HF or HF poorness here, HF concentration is generally the 20-80wt% of no ASO mixture.When Lewis base is pyridine, in poor HF logistics HF concentration for the 40wt% of no ASO mixture to 70wt%, be preferably 43-65wt%.In this scope, HF concentration is low more, and HF-pyridine mixture is easy more with separating of ASO subsequently, but steam stripped fund and process cost are also high more.

The operational condition of removing HF from incoming flow comprises that temperature is 10-260 ℃ (50-500 a °F), preferred 52-232 ℃ (125-450 °F), and pressure is 138-1724kPa (20-250psi), preferred 586-1379kPa (85-200psi).

With the stripping tower bottom product, or the logistics of poor HF or HF poorness, change the zone of separating ASO and HF-pyridine mixture over to.Preferred separation method is a gravity settling.Can in different mechanical means, carry out gravity settling, but the simplest equipment uses a quiescent centre, make poor HF logistics be separated into the mutually sour of the hydrocarbon phase of rich ASO and rich HF-pyridine mixture according to the gravity difference.Therefore, reclaimed two kinds of operation logistics, be the hydrocarbon stream of rich ASO and the acid stream of rich HF-pyridine mixture from separating device.In the alkylation operation, generally from operation, discharge rich ASO hydrocarbon stream, and the sour stream of rich HF-pyridine mixture is recycled to the reaction zone of this operation.

Say that more generally the separation method of ASO and HF-amine compound depends on the used certain amines coordination agent and the condition of first disengaging zone.When flowing out logistics is liquid, and when coordination agent also be liquid, separation method was generally aforesaid settling methods, but also comprises flash distillation, distillation, centrifugal, extraction, reaches based on density, compatibility or the difference that haves both at the same time and carry out isolating any proper method.

Generally, the concentration of coordination agent is 0.1-5wt% in the rich ASO hydrocarbon stream, but preferred concentration is 0.1-1.0wt%.In the HF alkylation operation of using pyridine, pyridine concentration is low more in the rich ASO stream, and the pyridine amount of losing from operation is more little, because generally discard rich ASO logistics from operation.As mentioned above, lose the result of pyridine from the alkylation operation, improve the volatility of circulation HF possibly, this has increased the danger of rapid evaporation atomizing, or improves the ratio that replenishes pyridine in operation, expense height like this.In this case, notice that another significant advantage of the present invention is very important, pyridine concentration that Here it is in rich ASO logistics is quite low.

Generally, ASO concentration is 0.1-50wt% in the rich HF-amine compound acid stream.When Lewis base was pyridine, ASO concentration was generally 0.1wt%-25wt% in the logistics of rich HF-Lewis base, and preferred concentration is 0.1-15wt%.In the HF alkylation operation of using pyridine, ASO concentration is low more in the rich HF-pyridine mixture, and the ASO amount that is recycled in the alkylation operation is low more.The ASO concentration of attenuating in HF alkylation operation is desired, because this has reduced the volume of acid regeneration stove.In addition, for given input speed and given acid regeneration stove size, it also is desired lowering the ASO concentration that is recycled in the alkylation operation, because this has lowered the concentration of ASO among the circulation HF, makes the concentration of coordination agent higher, suppresses rapid evaporation better.

Poor HF logistics is separated into the operating condition of rich ASO hydrocarbon stream and rich HF-amine compound acid stream, comprise that temperature range-18-260 ℃ (0-500 °F) is when forming ASO in the detergent alkylation equalization, preferred temperature is 149-260 ℃ (300-500 a °F), when forming ASO in motor spirit alkylation operation, preferred temperature is 66-149 ℃ (150-300 a °F).Pressure range is 138-1724kPa (20-250psi), and preferred pressure is enough to vaporization be minimized or stop vaporization, and the maintenance logistics is a liquid phase.

Can be by stripping be once more flowed in the acid of rich HF-pyridine mixture; Remove more HF, be separated into two kinds of logistics again through being separated, further lower the concentration of ASO in the acid stream of rich HF-pyridine mixture.An advantage that further lowers HF concentration is to isolate more ASO from the acid stream of rich HF-pyridine mixture.This further separation also need be costed, because extra stripping and gravity settling increase the fund and the process cost of operation.According to stripping and negative area, and the design of number of regions, because stripping and settled crystallization continuously, the concentration of ASO can be brought down below the level of 1.0wt% in the acid stream of rich HF-pyridine mixture.Further the operating condition of stripping HF comprises that temperature is about 10-260 ℃ (50-500 a °F) from the acid stream of rich HF-pyridine mixture, preferred 38-232 ℃ (100-450 °F), pressure is 138-1724kPa (20-250psi), preferred 586-862kPa (85-125psi).In the HF alkylation process, the speed of on average removing speed and its formation of ASO is suitable from operation.The optimum concn of returning ASO in the acid stream of rich HF-pyridine mixture of alkylation operation depends on technology and economic factors: the expectation concentration that comprises ASO in the capacity of regeneratory furnace and process cost and the alkylation operation.Generally speaking, produce speed and ASO concentration for any given ASO in the alkylation operation, it is high more to return in the acid stream of the rich HF-pyridine mixture in the operation ASO concentration, must be big more to the input speed of regeneratory furnace.This is because the ASO that returns the alkylation operation with the sour stream of rich HF-pyridine mixture must discharge through regeneratory furnace at last.Therefore, the present invention is to wherein the ASO aimed concn is lower, the alkylation operation particularly advantageous of the input speed finite capacity of regeneratory furnace.

Another embodiment of the present invention is useful when having water in the incoming flow.Because water concentration height in the recycle acid is not wished in corrosive danger in HF alkylation operation.Therefore, wish that in this operation water concentration remains on an acceptable level.In the present invention, the most of water in the feedstream can be removed with the disengaging zone of removing section H F from incoming flow.As mentioned above, this disengaging zone can be stripping tower, in this case, will contain the HF that tells in the overhead streams from incoming flow, and the part in the incoming flow or most of water.But also can operate this disengaging zone is not taken away most of water by overhead streams.Like this, stripping tower bottom product (or poor HF logistics) can contain the most of water that enters operation with incoming flow.Poor HF circulates into the disengaging zone, as the gravity settling district, produce rich ASO hydrocarbon stream and contain with poor HF flow to into the acid stream that is rich in HF-pyridine mixture of most of water.

One embodiment of the invention are most of water of removing in the logistics of rich HF-pyridine.This is that of the present invention another makes us surprising part, because people expect that the water in the rich HF-pyridine complex logistics will form pyridine-water azeotrope or pyridine-HF-water ternary azeotrope.If form any azeotrope, from operation, remove then and anhydrate, will also produce the bad result who removes pyridine.On the contrary, do not observe the formation of pyridine-water azeotrope or pyridine-HF-water azeotrope.Explanation to this phenomenon is that pyridine fully cooperates with HF, thereby can't form azeotrope with water.

Utilize this phenomenon, now found a kind of simple but effective method that before returning the alkylation operation, lowers water concentration in the acid stream that is rich in HF-pyridine mixture.The acid of being rich in HF-pyridine mixture is flow to few intermittently changing over to remove water in the stripping tower.This tower can be the formula distillation tower that boils again, or can be the tower that uses stripping air-flow such as Trimethylmethane water stripping from be rich in the logistics of HF-pyridine mixture.Separating institute's heat requirement can be provided by reboiler, or partly or entirely provides by being used for steam stripped air-flow.In addition, being used for the separated portions heat can provide by the rich HF-pyridine of preheating mixture acid stream before entering stripping tower.Although people expect that this tower contains generation the overhead streams of the pyridine-water azeotrope form of pyridine and most of water, or the tower bottom flow that contains most of water of pyridine-HF-water azeotrope form, but the overhead streams that stripping tower produces contains HF and water, but pyridine seldom, contain most of pyridine in the tower bottom flow, but water seldom.The water concentration of overhead streams is generally 5wt%-15wt%, is preferably 10wt%.

Removing the operating condition that anhydrates from the acid stream that is rich in HF-pyridine mixture comprises: temperature is 10-260 ℃ (50-500 a °F), preferred 38-232 ℃ (100-450 °F).Pressure should be 138-1742kPa (20-250psi), preferred 586-852kPa (85-125psi).

This H ₂The tower bottom flow of O stripping tower generally returns the alkylation operation, if this tower bottom flow contains significant ASO, it can be sent into phase separation region to remove ASO, and the tower bottom flow of poor ASO will return the alkylation operation then.Can at least intermittently from operation, discharge overhead streams, and directly send to neutralization.In addition, this overhead streams can be sent into another disengaging zone, tells cat head HF and returns the alkylation operation, produces to contain CBM (HF and H ₂The constant boiling mixture of O) bottom product discharges and sends to neutralization with it from operation.

In this embodiment of the present invention, the advantage that adds the disengaging zone that produces the bottom product that contains CBM is that the neutralization loss of HF obviously reduces.This adds the disengaging zone and can be the stripping tower of removing HF.This tower can be the formula distillation tower that boils again, or for using the tower of stripping air-flow such as Trimethylmethane.The function of this stripping tower is stripping HF from the overhead streams that contains HF and water.Separating institute's heat requirement is provided by reboiler, or it partly or entirely provides by being used for steam stripped air-flow.In addition, the preheating overhead gas stream can provide part to separate heat before entering tower.Like this, expense is also wanted in this HF loss attenuating, increases fund and process cost because other stripping step is operation.But according to the frequency that dewaters, water removal, neutral expense and depleted by product, possibility is reasonable economically to use stripping tower as can be known.When use adds stripping zone stripping HF, return in the HF stream of alkylation operation, be 0.1-5wt% based on the water concentration of no hydrocarbon mixture, be preferably 0.1-1wt%.

From HF/H ₂The operating condition of telling HF in the O overhead streams comprises: temperature is 38-260 ℃ (100-500 a °F), preferred 49-232 ℃ (120-450 °F).Pressure should be 138-1724kPa (20-250psi), preferred 586-862kPa (85-125psi).

Now describe the preferred embodiment that is shown among Fig. 1, the mixture that contains HF, HF-pyridine mixture, ASO and water of self-alkylation operation enters first stripping tower 12 from pipeline 10 in the future.In first stripping tower, in overhead streams, from incoming flow, optionally tell HF, and return the alkylation operation by pipeline 38 by pipeline 14 and 36.The tower bottom flow of first stripping tower is poor HF, changes second stripping tower 18 over to by pipeline 16.In second stripping tower 18, under selected condition, from the tower bottom flow of first stripping tower, optionally tell HF, obtaining HF and coordination agent mol ratio is 3: 1 to 5: 1.The tower bottom flow of second stripping tower is changed in the gravitational settler 24 by pipeline 22.In this gravitational settler, the tower bottom flow of second stripping tower is separated into overhead streams that is rich in ASO and the tower bottom flow that is rich in mixture by being separated.The overhead streams of settling vessel changes in neutralization and the ASO treatment facility by pipeline 26.The tower bottom flow of settling vessel returns the alkylation operation by pipeline 28 and through pipeline 38.The overhead streams that contains second stripping tower of HF and water enters the 3rd stripping tower 30 by pipeline 20.In the 3rd stripping tower 30, from the overhead streams of second stripping tower, optionally remove and anhydrate.The tower bottom flow of the 3rd stripping tower is rich in water, enters in HF neutralization and the water treating equipment by pipeline 32.The overhead streams of the 3rd stripping tower 30 is rich in HF, by pipeline 34 and 36, returns the alkylation operation through pipeline 38.

Embodiment 1

This embodiment shows the result who lowers HF content in the mixture that contains HF, pyridine and ASO, can obtain the high separation of ASO and HF-pyridine mixture.The mixture that will contain HF-pyridine mixture and ASO carries out the HF stripping, be separated into then the first rich ASO mutually with the first rich mixture mutually.The first rich mixture contains the HF of 50.3wt% mutually, and HF-pyridine mol ratio is 5, contains the ASO of about 9.7-10.5wt%.The first rich ASO contains the pyridine (neutralization back) of 0.12-0.5wt% and the HF of 3.2-3.3wt% mutually.The first rich mixture carries out the HF stripping mutually more then, and be separated into the second rich ASO mutually with the second rich mixture mutually.The second rich mixture contains the HF of 42.9wt% mutually, and HF-pyridine mol ratio is 3, and ASO content is lower than 1.0wt%.The second rich ASO contains the pyridine (neutralization back) of the 0.3wt% that has an appointment and the HF of about 0.5wt% mutually.

Like this, the alkylation catalyst that contains HF, ASO and pyridine can be separated into the rich pyridine logistics of ASO content less than about 1.0wt%, and it can return the alkylation operation and contain the rich ASO logistics of 0.12-0.5wt% pyridine, and it can be discharged from operation.

Embodiment 2

The present embodiment explanation is not inclined to formation pyridine-water azeotrope in HF-pyridine-water mixture.140g HF, 36g water and 79g pyridine are distilled under normal pressure.Observed two obvious temperature, kept the azeotropic tower top temperature in this temperature.First is 112 ℃, and this is equivalent to CBM (HF and H ₂The constant boiling mixture of O) boiling point, second is 182 ℃, this is equivalent to the boiling point of HF-pyridine mixture (HF-pyridine mol ratio is 3).

Embodiment 3

Table 1 shows the composition example of some logistics of operation shown in Figure 1.Present embodiment is based on conventional engineering calculation and laboratory test.In gravitational settler, the tower bottom flow of second stripping tower is separated into the overhead streams (can discard) that contains 99%ASO effectively and is contained the tower bottom flow that is lower than 1%ASO, and the latter can return the alkylation operation.Table 1

Logistics	Incoming flow 10	The first stripping tower underflow 16	The second stripping tower underflow 22	Sedimentation overhead streams 26	Sedimentation tower bottom flow 28	The second stripping overhead streams 20	The 3rd stripping overhead streams	The 3rd stripping tower underflow 32
									Form wt%
HF	79	55	40	＜1	43	85	94	38
									Pyridine	15	36	52	1	56	1	＜1	4
ASO	4	6	7	99	＜1	4	5	2
									Water	2	3	1	＜1	1	10	1	57
Add up to	100	100	100	100	100	100	100	100

Claims (8)

1. use HF and coordination agent mol ratio process for alkylating hydrocarbons apparently higher than 5: 1 HF-amine compound catalyzer, wherein form the logistics [10] that contains sour soluble oil (ASO) by product of this mixture that contains unacceptable amount, it is characterized in that reclaiming as follows most of described mixture recirculation and enter alkylation step:

(a) selective removal section H F from by product stream [10], it is 3: 1 to 5: 1 poor HF logistics [22] that generation contains HF and coordination agent mol ratio;

(b) separate formed poor HF logistics [22], form sour [28] mutually that the hydrocarbon phase [26] that is rich in ASO and poor ASO counted and contained most of mixture; And

(c) sour phase [28] recirculation enters the alkylating hydrocarbons step.

2. the method for claim 1 is characterized in that the concentration that poor HF logistics [22] contains HF counts 20-80wt% with no ASO.

3. the method for claim 1 is characterized in that the concentration that hydrocarbon phase [26] contains the amine coordination agent counts 0.1-5wt% with no ASO.

4. the method for claim 1 is characterized in that step (a) operating under the 10-260 ℃ of temperature He under the 138-1724kPa pressure.

5. the method for claim 1 is characterized in that step (b) is under-18-260 ℃ temperature and operate under the 138-1724kPa pressure.

6. each method among the claim 1-5 is wherein carried out in the stripping zone in (a) step, wherein contacts with Trimethylmethane by by product stream [10], optionally removes HF from this logistics, produces poor HF logistics [22].

7. each method among the claim 1-5 is characterized in that by product stream [10] contains H ₂O therefrom removes H with HF stream [20] in step (a) ₂O is then at H ₂From HF overhead stream [20], isolate portion water at least by stripping in the O knockout tower [30].

8. each method among the claim 1-5, wherein the amine coordination agent is a pyridine.

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