CN1022251C - Method for treating resin in purge vessel - Google Patents

Abstract

A method for removing unpolymerized gaseous monomers from a solid olefin polymer in a single purge vessel while deactivating Ziegler-Natta catalysts and organometallic catalyst residues present in said solid olefin polymer by utilizing a two diameter purge vessel wherein hydrolysis of the catalysts are effected in the portion of the reactor having the smaller diameter with the gaseous monomers being removed in the larger diameter portion.

Description

Method for treating resin in purge vessel

The present invention relates to the method for water process resin in degassing container, more specifically say, is to remove not polymerizable gas hydrocarbon monomer the low density ethylene-hydrocarbon polymer particle from low-pressure polymerization, simultaneously with a kind of method of catalyzer deactivation.

Known for a long time, alkene, for example ethene can be under polymeric reaction condition, uses the catalyzer that contains transistion metal compound, for example titanium tetrachloride and promotor, for example a kind of organometallics, for example triethyl aluminum carries out polyreaction.This type of catalyzer is commonly referred to as Z-type catalyst.

In the past, industrial manufacturing new LDPE (film grade) (being about 0.94 gram/cubic centimetre of density or lower polyethylene) is in the elongated tubular reactor, the application free-radical initiator makes ethylene high pressure homopolymerization (for example, pressure is at 15000 pounds/square inch or higher) and gets under condition of no solvent.Recently, study the method that successfully prepares new LDPE (film grade) in low pressure, this method has been compared obvious superiority with traditional high-pressure process.It is open in the common United States Patent (USP) of transferring the possession of 4,302,565 that a kind of low pressure method is arranged, and therefore its disclosed content is used as the reference content of this explanation.But be processed into film with the polyethylene application of known method that this kind low-pressure process is made, and the high toughness of this type of film tool is applicable to the packing purposes.

Above in the indicated patent, a kind of low-pressure vapor phase method of producing new LDPE (film grade) is disclosed, its density is about 22-36 scope for about 0.91-0.94 gram/cubic centimetre scope melt flow ratio, and remainder catalyst content is lower, tap density is higher.Be included in a kind of high-activity magnesium-titanium complex catalyst in this method and exist down, with ethene and one or more C ₃-C ₈Alpha-olefin copolymer closes, and this catalyzer is under special activation condition, impregnated on a kind of porous inert carrier material with organo-aluminium compound and makes.These multipolymers that make thus (when being used for these polymkeric substance, " multipolymer " speech used herein also means the polymkeric substance that comprises ethene and two or more comonomers) are as major portion (molar percentage is at least about 90%) and one or more C by ethene ₃-C ₈Alpha-olefin is as the multipolymer of less important part (molar percentage is no more than 10%), these C ₃-C ₈Alpha-olefin must not have side chain on any carbon atom than more close pair of key end of four carbon atom.The example of this class alpha-olefin has propylene, butene-1, hexene-1,4-methylpentene-1 and octene-1.

This catalyzer can prepare like this, at first by a kind of titanium compound (TiCl for example ₄), a kind of magnesium compound is (as MgCl ₂) and a kind of electronic donor compound capable (for example tetrahydrofuran (THF)) prepare a kind of precursor, for example these titaniums and magnesium compound can be dissolved in this electronic donor compound capable, separate obtaining this precursor then with crystallization process.Then with a kind of porous inert carrier (for example silicon-dioxide) with this precursor dipping, for example this precursor is dissolved in this electronic donor compound capable, this carrier is mixed with institute dissolved precursor, drying is to remove this kind solvent then.Prepared carrier through dipping can be handled and obtain activating with a kind of activator compound (for example triethyl aluminum).

Carry out this polyreaction and these monomers of gas phase for example can be carried out contact reacts with this activated catalyzer in fluidized-bed, temperature is about 30-105 ℃, and used low pressure is (for example, about 150-350 pound/square inch) below 1000 pounds/square inch.

The granular polymer that is generated can contain the gaseous state unconverted monomer that comprises detailed hydrocarbon.For safety, these gaseous monomers should be removed from granular resin, because under detailed hydrocarbon excessive concentration and aerobic existence, explosion hazard is arranged.In addition, also can require rationally to dispose these hydrocarbon, to meet the environmental protection standard of hydro carbons discharging.

In prior art, pointed out from polymer of monomers, to remove the technology of corresponding volatility unconverted monomer.For example United States Patent (USP) 4,197, and 399,3,594,356 and 3,450,183.

The nearer United States Patent (USP) 4,372,758 that is presented to people such as R.W.Bobst aspire to February 8 nineteen eighty-three and transfers commonly-assigned us discloses and removed the not degassing or the method for exhausting of polymerization gaseous monomer from solid olefin polymer.This kind degas method generally includes to be delivered to this solid polymer (for example, granular) in the degassing container, and this polymkeric substance is contacted with inert degassing gas with adverse current in this degassing container, carries the gaseous monomer that discharges from polymkeric substance with gas.

Disadvantageously, make in polyethylene and the polyacrylic method using Ziegler-Natta catalyst, after remaining catalyzer and promotor enter this degassing container in resin, by can not deactivation after outgasing with above-mentioned inert gas flow adverse current.These resistatess with air and reaction of moisture, form alcohols, aldehydes, ketone and alkane when degassing container flows out.Alcohol, aldehyde, the ketone that generates with oxygen reaction makes the resin strip scent of.The alkane that generates with the water reaction requires suitably to dispose to meet the environmental protection standard about the hydro carbons discharging.In addition, for safety, should from resin, remove these hydrocarbon gas products, because when the concentration of hydrocarbon is excessive, the danger of blast is arranged when having oxygen to exist.

This technology is to touch atmosphere (oxygen) before by means of catalyzer and promotor remaining in making resin, with this resin of moisture measurement, so just in add water vapour in rare gas element degassing air-flow.For impelling this hydrolysis reaction to be tending towards required excess water fully, be to bring into this exhaust airstream from the top of this degassing container.When the degassing container exhaust airstream is when leading to a torch, moisture existence and not serious is arranged, be to deliver to the MONOMER RECOVERY device but work as exhaust airstream, problem then takes place.Degassing container need be discharged the air-flow unwatering and technological problems occur to prevent the MONOMER RECOVERY device, for example condenser freezes, and will prevent that also moisture is recycled to reactor with monomer, otherwise in the throughput and the rosin products character of catalyzer detrimental action be arranged.

A solution of unwatering is to use dual molecular sieve bed dehumidification system from the discharge air-flow of degassing container, so just require to regenerate with high temperature nitrogen continually, also will overcome the degassing container vent gas and fall by dividing the pressure that ends the sifting bed layer with a gas blower.When needs when degassing container adds volume moisture, make owing to the size of molecular sieve bed has certain limitation that regeneration is frequent need supply a large amount of regeneration nitrogen simultaneously to unrealistic, make that this scheme is not ideal enough.

The scheme of another kind of unwatering from the degassing container exhaust airstream is to use two independently degassing containers.A container is used for discharging residual monomer with dry inert gas from resin, and this container venting port is switched to the MONOMER RECOVERY device.Second container is used for the moisture process resin, and the vent gas of this container is passed to torch.Because this scheme cost height, and need to increase the structure height of degassing container so that resin can flow to another container with gravity, or increase handling equipment with resin from a container transport to another container, thereby need with more spaces, so industrial implementation is unfavorable.

Also disclose the technology of remainder catalyst deactivation in some fluoropolymer resins in addition, for example United States Patent (USP) 4,029,877(1977 issued June 14), United States Patent (USP) 4,314,053(1982 issued February 2) and English Patent 1,553,565(1979 issued October 3).These disclosed remainder catalyst deactivation methods are to answer water and the reaction of this remainder catalyst, make it inactivation.But disadvantageously, disclosed water treatment method has such shortcoming, and promptly the monomer that exists in this polymeric resin particles is subjected to toxication easily, and needs independent removing step to remove moisture from this monomer.

The invention provides in single degassing container of being subjected to extensively expecting removed not polymerization gaseous monomer from solid olefin polymer, and simultaneously with a kind of method of Ziegler tower catalyzer deactivation remaining in the described solid olefin polymer, this method comprises goes into the described polymer transport that is in first inert gas flow that contains a kind of delivering gas in the degassing container, this container has an epimere, hypomere be connected described on, the interlude of hypomere, the diameter of described epimere is 1.5 to 3.0 times of described hypomere diameter, described polymkeric substance is contacted with a kind of degassing back flow of gas in described epimere and produce second air-flow, to contain described degassing gas, described degassing gas, described second air-flow of described delivering gas and described gaseous monomer is discharged from described epimere, the described solid olefin polymer that will contain described catalyzer was led described interlude and was entered described hypomere from described epimere, to contain moisture second the degassing gas send into described hypomere and with described solid olefin polymer with counter current contact, institute's water content is enough to make described Ziegler-Natta catalyst and the organo-metallic catalyst deactivation that is present in the described solid olefin polymer in described second degassing gas, described second degassing gas is discharged from the close described interlude part of described hypomere, and described solid olefin polymer is discharged from described hypomere.

Accompanying drawing is the block diagram that the present invention uses single degassing container.

For convenience of explanation, the present invention describes by the low pressure low density ethylene copolymer, but self-evident the present invention is not limited thereto copolymer, but limited by each claim scope of the present invention fully. For example, method of the present invention can be applicable to process the solid olefin polymer outside the low pressure low density ethylene copolymer, other copolymers of for example homopolymers of ethene and propylene, and ethene and propylene.

Words and phrases used herein " low pressure low density ethylene copolymer " meaning is at least a C at least about 10% molar percentage ₃-C ₈Alpha-olefin comonomer (for example, propylene, butene-1, hexene-1,4-methylpentene-1 and octene-1) is at the multipolymer of low pressure (for example 150-350 pound/square inch) copolymerization.The density of these multipolymers generally is not more than 0.94 gram/cubic centimetre, and typical case is about 0.91-0.94 gram/cubic centimetre.In addition, these multipolymers generally have narrow molecular weight distribution, the about 2.7-4.5 of Mw/Mn.In aforesaid U.S. Patent 4,302, a kind of method special case for preparing these polymkeric substance has been described more comprehensively in 565, it is more fully open that these applications can reach with reference to this method.The average diameter of particles that the made granular polymer of disclosed this kind gas phase process can have in these applications is about 0.03-0.05 inch order of magnitude.

According to reaction conditions and concrete comonomer hydrocarbon, the contained gaseous state unconverted monomer (can comprise ethene, one or more these comonomer hydrocarbon, stable hydrocarbon and reactionless active alkene) of the solid low pressure low density ethylene copolymer of gained amount can be up to about 1.5-4.5%(weight).According to environment protection restriction, forbid possibly these hydrocarbon directly are discharged in the atmosphere, the more important thing is safety problem, general requirement reduces the content of hydrocarbon, in case formation explosive mixture when contact with oxygen.

In addition, to this solid resin particle that contains remainder catalyst and promotor, should make it deactivation as described above, in order to avoid fluoropolymer resin has color or unpleasant odor.Implement method of the present invention and can in single degassing container, remove these monomers effectively and prevent remainder catalyst and the discoloration of promotor, also will handle these monomers in addition the prior art and needn't resemble.

Method of the present invention is best suited for by United States Patent (USP) 4,303, the deactivation of remainder catalyst in 565 catalyzer and the promotor resulting polymers.

With reference to accompanying drawing, with olefin polymer resin, for example press United States Patent (USP) 4, the made resin of 303565 disclosed methods is sent into first inert gas flow 10 and is entered in the degassing container 12 with two kinds of diameters, this container has an epimere 14, discharge gaseous monomer, an interlude 16 and a hypomere 18 therein from the resin that is landing, carry out the hydrolysis reaction of remainder catalyst and promotor therein, this hypomere is connected with a conical part 20 of this reactor.The epimere 14 of degassing container 12 is round shape basically, and its diameter is about 1.5-3.0 a times of basic diameter for columnar hypomere 18, preferably about 2 times.

The design of degassing container 12 is to become plug flow when making resin be downward through container basically." plug flow " meaning is that resin particle flows downward with constant speed on the entire cross section of degassing container 12, so the residence time of all resins particle in this container equates basically.

The inertia degassing gas of doing 22 is sent into degassing container 12 by interlude 16, and feeding the position is in the top of hypomere 18, and passes to conical baffled 24 bottom, and this baffle plate is between epimere 14 and interlude 16.Make then the degassing gas 22 enter epimere 14, and with the olefin polymer resin counter current contact of landing.

Carry the gaseous monomer that olefin polymer resin discharged from epimere 14 by inertia degassing gas 22 gas of doing, and form and contain dried inertia degassing gas 22.The air-flow of first inert gas flow 10 and the monomer gas that discharges is discharged by strainer from degassing container 12 then, delivers to vent gas retrieving arrangement or torch by pipeline 28 then.

The part of inert gas flow 22 can be drawn by pipeline 30, with wet degassing air-flow 24 merging, sends into degassing container 12 by cone segments 20 then again.The bottom of flow cone body 36 in wet degassing air-flow 24 is introduced, this cone is positioned at the bottom of hypomere 18 and the top of cone segments 20, and the design of interior flow cone body 36 is to make resin become plug flow.In addition, interior flow cone body 36 provides the wet degassing air-flow that rationally is evenly distributed for the hydrolytic action of carrying out in the hypomere 18.In the bottom of interlude 16 and the top of hypomere 18 cone 38 of gathering materials is arranged.The design of the cone of the gathering materials vapor pipe 40 and the cone 38 of gathering materials is vaporous water hydrolysis products and wet degassing gas can be drawn, and prevents that moisture from entering in the epimere 14 of degassing container 12.The side line derivated of these hydrolysates and gas is discharged into a torch by pipeline 44 then by a conventional formula particle collector 42 then.Resin is then discharged from cone segments 20 by pipeline 46.

In the method for the invention, can use conventional formula material transfer equipment and technology.Resin depends on the ultimate density of monomeric starting point concentration and requirement in this resin at epimere 14 required short residence time(SRT)s, and can determine with known mass transfer method of calculation.For low pressure low density ethylene-butene-1 copolymer, generally need in epimere 14, stop about 1 hour with the density loss of detailed hydrocarbon to safety with meet the degree of environmental protection requirement.The residence time of resin in hypomere 18 depended on this remainder catalyst of hydrolysis and required time of promotor.For a kind of density is 0.918 gram/cubic centimetre, is the ethene-butene-1 copolymer of 1.0 low-pressure polymerization 75-80 ℃ melt flow index, and general hydrolysis required time is about 5-20 minute.

Method from moisture to hypomere that introduce is water vapor to be sprayed onto in the dry inertia degassing gas of drawing for flow cone body 36 bottoms in leading to.The effectiveness of interior flow cone body 36 provides the plug flow of resin, and the wet degassing air-flow that rationally is evenly distributed is provided.Determine about the size and the position that are applied to flow cone body in this kind in this degassing container, be at " The Use of Flow Corrective Inserts in Bins " according to J.R.Johanson, Transaction of the ASME, May, 1966, a kind of method that is proposed.

The ratio that adds water vapor in degassing container is to be in excess in and this remainder catalyst and the required stoichiometry numerical value of promotor reaction, carries out fully to impel this hydrolysis reaction.Water vapor adds the preferably per 1,000,000 pounds of about 100-3000 pound of the resin water vapors of ratio, decides on the type and the content of remainder catalyst and promotor.Can regulate the ratio of steam rates and the resin flow of discharging, to keep per 1,000,000 pounds of ratios that resin is a 100-3000 pound water vapor from degassing container 12.

For preventing too much to produce resin storing problem, find to be necessary to guarantee to make water vapor all condensation can not be arranged after before spraying into this inertia degassing gas, reaching because of resin contains moisture.If need prevent the measure of condensation, can be with the inertia degassing gas heating of sending into the degassing container bottom to the temperature of this resin or be lower than this temperature.Have found that be necessary to keep the temperature of this resin to be lower than its softening temperature or melting temperature, for the low pressure low density ethylene copolymer, this temperature is about 100-110 ℃.Preferably tried one's best near the cone segments of degassing container 12 in the position that water vapor feeds in the inertia degassing gas.Preferably make the inertia degassing airshed in the hypomere 18 that passes to degassing container 12 enough high, hang down 5 ℃ with the dew point that keeps the wet degassing gas of this kind at least than the resin temperature in the degassing container, to prevent the water vapor condensation.Under the cold condition of climate, may need to improve this inertia degassing gas flow and/or with hypomere 18 insulations, to prevent the condensation on the inwall of degassing container of water steam.

Pressure in the degassing container 12 is can height different, but is preferably in the lower positive pressure of maintenances in the degassing container 12, because pressure is when hanging down, the rate of diffusion of gaseous monomer is higher.In degassing container 12, should keep malleation, at first be to prevent vacuum and air or oxygen is sucked, and might form explosive mixture with detailed hydrocarbon, secondly, the normal running of the cone 38 that needs to guarantee to gather materials.For guaranteeing to remove wet degassing air-flow from the cone 38 of gathering materials, the pressure that the pressure at cone position must add upper pipeline and fly-ash separator 24 greater than the pressure of this torch that gathers materials of this in degassing container 12 falls.This pressure reduction impellent will cause a kind of flow condition, and can remove a large amount of moisture by the cone 38 of gathering materials, thereby prevent that moisture from flowing into the epimere 14 of degassing container 12.Though suitable pressure depends on many factors, those skilled in the art use known mass transfer and pressure and fall computing technique and have the ability to carry out this kind and determine.

The flow that leaves degassing container 12 by the cone venting port 40 that gathers materials is the flow greater than the wet degassing air-flow 34 that feeds from interior flow cone body 36 bottoms.So just guaranteed that a certain amount of dried degassing gas 22 is drawn towards the below from the epimere 14 of degassing container 12, enters the exhaust recovery system of degassing container to prevent water steam.

The dried degassing gas that flows downward around gathering materials cone 38 is caught the wet degassing gas that all are overflowed at random, and it is taken away from the cone venting port 40 that gathers materials.

Formed by the space between solid resin particle and these solid resin particles by the sedimentation resin bed that degassing container 12 also flows downward with piston-type basically.When resin being sent into this degassing container, the monomer gas that these spaces are just contained delivering gas and discharged.When resin in the process that the epimere of degassing container 12 flows downward, the dried degassing air-flow of sending into from interior flow cone body 24 bottoms is just replaced the monomer gas that is discharging this delivering gas and these spaces.When resin flows down to the cone 38 of gathering materials, just the dried degassing gas in the space is taken to flow downward by resin.Being carried the dried degassing gas volume that flows downward can calculate, and depends on the deposition density of degassing gaseous species, degassing container working pressure, resin particle density and resin.Remove outside the dried degassing gas that carries downwards by the space, preferably also have some to do degassing gas in addition and guide the below into, and discharge, upwards move in this container to prevent that water from dividing from the cone 38 of gathering materials from the epimere of degassing container 12.Being directed the additional degassing gas volume of doing of mobile downwards generally is to be twice in the particle space of being calculated to carry the dried degassing gas volume that gets off.The dried degassing gas volume of flow cone body 24 bottoms equals upwards to carry these resins and reach the required flow of regulation hydrocarbon concentration with gas with the resin adverse current in introducing, and adds the flow that causes the cone 38 of gathering materials downwards.

As described above, determine the to gather materials size of cone 38 should adopt the Johanson method to reach the plug flow of these resins.Preferably like this, when the size of the cone 38 of gathering materials is to keep in the limited range of plug flow, should stipulate like this for this standoff distance that gathers materials between cone base and this degassing container wall, make that guiding the degassing gas velocity of below and humid gas in hypomere 18 velocity of flow that makes progress into by this annular space is more or less the same.The moisture that so just might accomplish to move to the epimere of degassing container 12 reduces as far as possible.

The resin that is positioned at cone 38 tops that gather materials will be an exsiccant, and still contain remaining catalyzer and promotor.Therefore, if there is moisture in a small amount to escape in the epimere 14 of degassing container 12, will be absorbed by these resins and/or with catalyzer and the promotor reaction of remnants, make moisture-free in the air-flow of discharging by this degassing container top.

In enforcement of the present invention, used this kind of rare gas element can be to be any gas of inert for the resin that is outgased and the sort of gaseous monomer of being discharged.Optimum degassing gas is nitrogen, is other gas of inert in the method but also can use.Preferably nitrogen content is about at least 90% in this degassing gas, and can not be oxygenous in this degassing gas.The concrete detailed hydrocarbon that the rich oxygen content of permission is carried because of institute's gas is different.When improving the concentration of hydrocarbon in the presence of aerobic, the danger of blast also increases, and this numerical value is different because of the kind of hydrocarbon.Ideal situation is an oxygen-free gas in this degassing gas, but can allow a small amount of existence, decides on the monomeric species that the hydrocarbon concentration in this degassing container and institute's gas are carried.Those skilled in the art promptly are easy to determine the permissible level of oxygen behind given a kind of concrete monomer.Certainly, also can contain gaseous monomer in a small amount in this degassing gas, but, then can influence their rate of diffusion as previously mentioned, thereby have influence on the resin residence time along with their concentration increases.Application also has additional advantage than pure nitrogen gas as degassing gas, be exactly to propose more hydrocarbon gass from gas on the resin particle, and all pure nitrogen gas all can be discharged and can not resemble and cause topsoil the impure gas with the resin of discharging.So preferably use pure nitrogen gas as degassing gas.

MONOMER RECOVERY can adopt several different methods.Because this catalyzer and promotor resistates have lost deactivation, so preferably adopt United States Patent (USP) 4,372,758 described MONOMER RECOVERY methods, and its advantage is no longer to need further to handle these monomers are with from wherein unwatering.

Below by Examples set the present invention.

Example 1:

Use United States Patent (USP) 4,302,565 disclosed gas phase process and prepare a kind of ethylene-butene copolymer (density 0.918 gram/cubic centimetre; Melt flow index 1.0).

This Preparation of catalysts is that titanium chloride, magnesium chloride, tetrahydrofuran (THF), diethyl aluminum chloride and tri-n-hexyl aluminum are added on a kind of carrier based on silicon-dioxide.As promotor, the speed that feeds to this reactor is 6.04 gram/minute with triethyl aluminum.

Through after the depressurization step, under inert gas atmosphere with this kind granular resin from this reactor is sent to as shown in Figure 1 a degassing container.This resin contacts with pure nitrogen gas at epimere 14, contacts with purity nitrogen and water vapor in hypomere 18.At material balance shown in the table 1 and streams temperature and pressure, and adopt the sign among Fig. 1 to number so that contrast.

Table 1

Illustrate/streams 10 34 44 22 28 46

Nitrogen (Pounds Per Hour) 368 230 330 225 493-

Ethene (Pounds Per Hour) 250---250-

Butylene (Pounds Per Hour) 358---357.5 0.5

Unreacting hydrocarbon (Pounds Per Hour) 189-4.6-188.7 0.3

Resin (Pounds Per Hour) 16537----16537

Water vapor (Pounds Per Hour)-3.3 0.6---

Total flux (Pounds Per Hour) 17,702 233.3 335.2 225 1289.2 16537.8

Temperature (℃) 80 70 80 70 80 75

Pressure (pound/square inch, 15 43433

Gauge pressure)

Testing by the ethylene-butene copolymer that container 12 is discharged shows, does not have smell in this multipolymer, represents that deactivation has taken place these remainder catalysts.

Claims (11)

1, in a kind of single degassing container, from a kind of solid olefin polymer, remove not polymerization gaseous monomer, simultaneously with a kind of method of Ziegler-Natta catalyst remaining in the described solid olefin polymer and organo-metallic catalyst deactivation, go in the degassing container comprising the described polymer transport that will be in first inert gas flow that contains a kind of delivering gas, this container has an epimere, hypomere be connected with one described on, the interlude of hypomere, the diameter of described epimere is 1.5-3.0 a times of described hypomere diameter, described polymkeric substance is contacted with a kind of degassing back flow of gas in described epimere and produce second air-flow, to contain described degassing gas, described second air-flow of described delivering gas and described gaseous monomer is discharged from described epimere, the described solid olefin polymer that will contain described catalyzer was led described interlude and was entered described hypomere from described epimere, to contain moisture second the degassing gas send into described hypomere and with described solid olefin polymer with counter current contact, institute's water content is enough to make and is present in described solid olefin polymer with counter current contact in described second degassing gas, institute's water content is enough to make described Ziegler-Natta catalyst and the organo-metallic catalyst deactivation that is present in the described solid olefin polymer in described second degassing gas, described second degassing gas is discharged from the close described interlude part of described hypomere, and described solid olefin polymer is discharged from described hypomere.

2, according to a kind of method of claim 1, wherein the described delivering gas in described first inert gas flow is a nitrogen.

3, according to a kind of method of claim 1, wherein the described degassing gas in described epimere is nitrogen.

4, according to a kind of method of claim 1, wherein described second degassing gas in described hypomere is nitrogen.

5, according to a kind of method of claim 1, the diameter of wherein said epimere is 2 times of described hypomere diameter.

6, according to a kind of method of claim 1, wherein the described moisture in described second degassing gas in described hypomere is water vapor.

7, according to a kind of method of claim 6, wherein to join the ratio in the described degassing container be to be in excess in and described remainder catalyst and the required stoichiometric number of promotor reaction to this water vapor.

8, according to a kind of method of claim 1, wherein the temperature of the described solid olefin polymer in described degassing container is softening temperature or the fusing point that remains below described solid olefin polymer.

9, according to a kind of method of claim 1, the dew point that the flow that wherein said inertia degassing gas enters described hypomere is enough to keep wet degassing gas is than low 5 ℃ at least of the minimum temperatures of this solid olefin polymer in the described degassing container.

10, according to a kind of method of claim 1, wherein said solid olefin polymer is a kind of low density ethylene-hydrocarbon type copolymer of low-pressure polymerization.

11, according to a kind of method of claim 10, the low density ethylene-hydrocarbon type copolymer of wherein said low-pressure polymerization is a kind of ethylene-butene copolymer.

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