Abstract: The expanded bed direct-contact system uses a multistage expanded bed chamber for heat exchange between heated particles, falling under the force of gravity, and an upwardly directed stream of cool fluid. As the heated particles fall through a plurality of vertically-arrayed stages of the multistage expanded bed chamber and exchange thermal energy with the stream of cool fluid, a stream of heated fluid, and a volume of cooled particles, are produced. Porous plates are respectively received within the stages of the multistage expanded bed chamber for increasing residence time of the particles, and the porous plates, as well as the plurality of stages, are connected to one another by a plurality of downcomers, each also formed from a porous material.

Abstract: Described herein is a polymerization reactor system comprising at least one loop reactor and/or at least one transfer line, and further comprising at least one withdrawal valve, wherein the at least one withdrawal valve is mounted to a wall of a lower horizontal segment of the loop reactor and/or to a wall of the transfer line, at an angle a of more than 0° and equal to or less than 85°, determined from perpendicular to a tangent of the wall at the mounting position in flow direction of a slurry in the loop reactor and/or in the transfer line.

Abstract: Current chemical batch processing technology is based on batch reactors, which typically consist of a vessel, in which reactants are processed. The batch reactor comprises a reactor vessel having at least one first thermal transfer element; a removable top cover for sealing the reactor vessel; a baffle component having at least one second thermal transfer element; and an agitator component, wherein each of the at least one first thermal transfer element and the at least one second thermal transfer element is independently controllable, and wherein the batch reactor comprises a thermal transfer surface-to-volume ratio of at least 6:1. This increases the thermal transfer potential and the thermal energy transfer efficiency of the batch reactor, thereby to increase production speed and throughput.

Abstract: The present invention generally relates to methods and systems for capturing a Lewis acid gas (e.g., CO2). In some embodiments, the methods and systems utilize an ionic liquid incorporated into one or more electrochemical cells.

Abstract: Provided is a collection of polymer beads, wherein the volume distribution expressed as a function of bead diameter comprises (A1) a first peak having a maximum of PM1 at diameter PD1 and having full width at half maximum of 75 ?m or less, (A2) a second peak having a maximum of PM2 at diameter PD2 and having full width at half maximum of 75 ?m or less; and (B1) a valley having a minimum value of VM1 at a diameter between PD1 and PD2, wherein VM1 is less than 0.25*PM1 and VM1 is also less than 0.25*PM2. wherein the polymer beads comprise polymerized units of one or more monofunctional vinyl monomer and one or more multifunctional vinyl monomer.

Abstract: The invention relates to a reactor and to a method for continuous polymerization, in which said reactor for the continuous production of polymers, particularly synthetic rubbers, contains at least one substantially tubular reactor housing (4), wherein said reactor housing (4) has a drive shaft (30) that is connected to at least one agitator (38) arranged such that it can rotate inside the reactor housing (4), and the agitator contains at least one, and preferably two, three or four helical mixing elements (24) which are designed to be preferably close to the wall or to come into contact with the wall.

Abstract: The present invention relates to an oligomerization process using a reaction device comprising a dispersion means. In particular, the process relates to the oligomerization of ethylene to give linear ?-olefins, such as 1-butene, 1-hexene or 1-octene, or a mixture of linear alpha-olefins.

Abstract: An olefin polymerisation method and arrangement comprising polymerising at least one olefin in gas phase in a fluidised bed in the presence of an olefin polymerisation catalyst in a polymerisation reactor having a vertical body; a generally conical downwards tapering bottom zone; a generally cylindrical middle zone, above and connected to said bottom zone; and a generally conical upwards tapering top zone above and connected to said middle zone wherein (i) fluidisation gas is introduced to the bottom zone of the reactor from where it passes upwards through the reactor; (ii) the fluidisation gas is withdrawn from the top zone of the reactor; (iii) a fluidised bed is formed within the reactor where the growing polymer particles are suspended in the upwards rising gas stream; and wherein the polymerisation reactor has an operating temperature set point and which reactor comprises at least one temperature measurement sensor, wherein a temperature difference (DT) between the temperature measurement sensor (Tm), an

Abstract: A method for the removal of unreacted olefin monomer(s) from polyolefin product particles of an olefin polymerization reaction, the method including: contacting the polyolefin product particles with a countercurrent flow of a purge gas in a purge vessel under conditions allowing diffusion of unreacted monomer and other gaseous substances from the polyolefin product particles into the countercurrent flow of the purge gas to produce purged particles; wherein the velocity of the purge gas exceeds 50% of the calculated minimum fluidization velocity of the polyolefin product particles in the purge vessel (Umf), is provided.

Abstract: The present invention relates to a process for the production of polyacrylonitrile by polymerisation of a reaction mixture comprising acrylonitrile in a solution where the solvent is a eutectic system comprising a quaternary ammonium compound and a hydrogen donor. Such process allows for the production of a polyacrylonitrile having a desirably high molecular weight, whilst polymerisation time is reduced, and where the solvents are environmentally benign, biodegradable and may be reused in the polymerisation process.

Abstract: The present invention relates to a process for removing polymer material from a gas-solids olefin polymerization reactor wherein the gas-solids olefin polymerization reactor is connected to the top part of an outlet vessel via a feed pipe wherein the powder surface of discharged polymer material and the barrier gas injection point are situated in the outlet vessel as such to fulfill the following criteria: R?=X/Y?2.0; and R?=X/D?1.

Abstract: This disclosure relates to a method and an apparatus for the delivery of a multi-component olefin polymerization catalyst to a polymerization reactor. The components soluble in a first solvent are delivered under pressure along with that solvent in a first delivery conduit. The components that are insoluble in the first solvent but are soluble in a second solvent are delivered under pressure in a second delivery conduit which is arranged coaxially with and disposed within the first conduit, such that the inner conduit and outer conduit terminate at a common catalyst component mixing conduit which extends into the polymerization reactor and in which the catalyst components mix to form an active polymerization catalyst.

Abstract: Monomodal copolymers of ethylene and molding compositions comprising such copolymers, wherein the copolymers have a density determined according to DIN EN ISO 1183-1, variant A in the range from 0.938 to 0.944 g/cm3, a melt index MFR21 determined according to ISO 1133 at 190° C. under a load of 21.6 kg in the range from 12 to 17 g/10 min, a weight average molar mass Mw in the range from 140 000 g/mol to 330 000 g/mol, a polydispersity Mw/Mn in the range from 9 to 17, and a content of comonomer side chains per 1000 carbon atoms Cx equal to or above a value defined via equation (I) Cx=128.7?134.62×d?, wherein d? is the numerical value of the density of the copolymer in g/cm3, the use of the copolymers for producing injection-molded articles, as well as injection-molded articles comprising the copolymers, and process for the preparation of such monomodal copolymers.

Abstract: The present disclosure relates generally to a system having a reactor system with a polymerization reactor and a feed system fluidly coupled to a feed inlet of the reactor. The feed system supplies components to the reactor via the feed inlet, and the reactor has a flow path that continuously conveys the components through the reactor and subjects the components to polymerization conditions to produce a polymer. The system also has an analysis system coupled to the reactor for online monitoring of a particle size of the polymer. Further, the system includes a control system, coupled to the analysis and feed systems, that receives a signal from the analysis system indicative of the monitored particle size of the polymer and adjusts an operating parameter of the feed system to control a flow rate of at least one of the components to the reactor based at least on the signal.

Abstract: Parallel uses of microfluidic methods and devices for focusing and/or forming discontinuous sections of similar or dissimilar size in a fluid are described. In some aspects, the present invention relates generally to flow-focusing-type technology, and also to microfluidics, and more particularly parallel use of microfluidic systems arranged to control a dispersed phase within a dispersant, and the size, and size distribution, of a dispersed phase in a multi-phase fluid system, and systems for delivery of fluid components to multiple such devices.

Abstract: An eductor, a process and apparatus for gas phase polymerization of olefins in a polymerization reactor are disclosed. The process and apparatus employ an eductor which has an inlet which makes a bend of less than about 90° toward the outlet after entering the mixing chamber of the eductor.

Abstract: A reverse-phase suspension polymerization process for the manufacture of polymer beads comprising forming aqueous monomer beads comprising an aqueous solution of water-soluble ethylenically unsaturated monomer or monomer blend and polymerizing the monomer or monomer blend, to form polymer beads while suspended in a non-aqueous liquid, and recovering polymer beads, in which the process comprises providing in a vessel (1) a volume (2) of non-aqueous liquid wherein the volume of non-aqueous liquid extends between at least one polymer bead discharge point (3) and at least one monomer feed point (4), feeding the aqueous monomer or monomer blend through orifices (5) into, or onto, the non-aqueous liquid to form aqueous monomer beads, allowing the aqueous monomer beads to flow towards the polymer bead discharge point initiating polymerization of the aqueous monomer beads to form polymerizing beads, wherein the polymerizing beads form polymer beads when they reach the polymer bead discharge point, removing a suspensi

Abstract: Disclosed herein is a transformation system to create a nutritional substance product that obtains information regarding the nutritional substance components to be transformed, the desired transformation, and the desired properties, including nutritional content, of the transformed nutritional substance, and dynamically modifies the transformation in response to this information to optimize a nutritional, organoleptic or aesthetic value of the nutritional substance product after it has been prepared for consumption. Various component nutritional substances are individually or collectively transformed and preserved, then provided to consumers or conditioners in a format allowing retrieval of preparation instructions unique to the individual nutritional product at the time of preparation and intended to optimize a nutritional, organoleptic, or aesthetic value targeted by the transformer during transformation.

Abstract: Provided is a resin article produced by melt processing and having layers formed by a layer-separation. The resin article may include a first resin layer, a second resin layer formed on the first resin layer and an interface layer including a first resin and a second resin and formed between the first resin layer and the second resin layer. The resin article may have improved mechanical and surface characteristics. Further, since coating or plating is not required for manufacturing a resin article, a manufacturing time and/or cost can be reduced, and productivity can be increased.

Abstract: Speriodal polymer beads having a uniform size are prepared by polymerizing uniformly sized monomer droplets formed by dispersing a polymerizable monomer phase over a cross-flow membrane into an aqueous phase. A shear force is provided at a point of egression of the polymerizable monomer phase into the aqueous phase, the direction of shear substantially perpendicular to the direction of egression of the monomer phase. The polymer beads can be employed in applications where beads having uniform diameters of 10 to 180 ?m are useful.

Abstract: A process for producing water-absorbing polymer particles by polymerizing an aqueous monomer solution in a polymerization reactor with at least two axially parallel rotating shafts, wherein the polymerization is performed in the presence of an inert gas and under positive pressure.

Abstract: The instant invention is a polyethylene composition, method of producing the same, articles made therefrom, and method of making the same. The polyethylene composition according to the instant invention comprises (1) less than or equal to 100 percent by weight of the units derived from ethylene; and (2) less than 15 percent by weight of units derived from one or more ?-olefin comonomers. The polyethylene composition according the instant invention has a density in the range of 0.907 to 0.975 g/cm3, a molecular weight distribution (Mw/Mn) in the range of 1.70 to 3.62, a melt index (I2) in the range of 2 to 1000 g/10 minutes, a molecular weight distribution (Mz/Mw) in the range of less than 2.5, and a vinyl unsaturation of less than 0.06 vinyls per one thousand carbon atoms present in the backbone of the composition.

Abstract: A device for producing ethoxylation derivatives includes an assistant circulation loop with lower starting quantity is added on the base of the main circulation loop, and the assistant circulation pump is started first when slight chain initial dose is added with low flow rate of the ethylene oxide and high growth rate of polyreation; when the amount of reactant gets to the starting quantity of the main circulation pump, the main circulation loop is started with high flow rate of ethylene oxide. The two circulation loops cooperate with each other shorten reaction time and high yield in one batch; a pre-reaction cavity with smaller inner diameter than that of the main body of the reactor is extended from the bottom of the main body of the device, so that lower chain initial dose can start the assistant circulation pump, and then start the assistant circulation loop.

Abstract: Monomer solution and liquid solution immiscible with the monomers in the monomer solution are cocurrently jetted upwardly in a pulsating manner in a reaction vessel. Monomer droplets are allowed to rise up in a controlled and smooth manner under the dynamic forces exerted by differential flow rate and differential pressure between the monomer and liquid solutions and the differential densities between the monomer and liquid solutions without causing coalescence, agglomeration and breakup of the monomer droplets and to stabilize by partial polymerization of the droplets at 50-60° C. The monomer droplets flow out horizontally into a polymerization reactor and get polymerized in the polymerization reactor under agitation at 80-85° C. The polymer beads are dried at 80-100° C. and sieved.

Abstract: Copolymer are formed by polymerizing C4 to C7 isoolefin monomers and alkyl-styrene monomers. The method comprises first providing feed streams into a reactor. The various feed streams provide monomers, a polar diluent or polar diluent mixture, and a catalyst system into the reactor. In the reactor, the feed streams contact one another so that the monomers form a polymer in a stable slurry, wherein the amount of polymer in the slurry yields a slurry concentration greater than 22 wt %. The ratio of moles of polymer formed per mole initiator is in the range of 0.25 to 4.0 moles polymer per mole of initiator.

Abstract: Provided herein are in vivo gelling ophthalmic pre-formulations forming a biocompatible retinal patch comprising at least one nucleophilic compound or monomer unit, at least one electrophilic compound or monomer unit, and optionally a therapeutic agent and/or viscosity enhancer. In some embodiments, the retinal patch at least partially adheres to the site of a retinal tear. Also provided herein are methods of treating retinal detachment by delivering an in vivo gelling ophthalmic pre-formulation to the site of a retinal tear in human eye, wherein the in vivo gelling ophthalmic pre-formulation forms a retinal patch.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase in a reaction chamber, wherein the monomer solution is metered into the reaction chamber via at least one bore, and the diameter is from 210 to 290 ?m per bore and the metering rate is from 0.9 to 5 kg/h per bore.

Abstract: A method for the delivery of a catalyst to a polymerization reactor is disclosed, comprising: contacting a catalyst with a carrier fluid comprising an inert hydrocarbon in gaseous form, the inert hydrocarbon having a normal boiling point of about ?1° C. to about 81° C.; and flowing the carrier fluid to the polymerization reactor such that the carrier fluid transports the catalyst to the polymerization reactor. A catalyst delivery system is disclosed, comprising: a catalyst vessel for containing a catalyst; a catalyst injection line for delivering the catalyst to a polymerization reactor, the catalyst injection line being in fluid communication with the catalyst vessel and the polymerization reactor; and a carrier fluid line in fluid communication with the catalyst injection line for delivering a carrier fluid comprising an inert hydrocarbon to the catalyst injection line, the inert hydrocarbon having a normal boiling point of about ?1° C. to about 81° C.

Abstract: There is provided a method of producing a composition having a continuous phase and a disperse phase dispersed finely with low polydispersity in the continuous phase, with high production efficiency. The composition is produced by the production method including the steps of: (A) passing the swirling flow of the continuous phase liquid into a cylindrical body the circumferential surface of which is either in part or entirely formed by a porous membrane, (B1) supplying the disperse phase fluid to the swirling flow via the porous membrane to form the particles of the disperse phase on the porous membrane, and (B2) detaching the disperse phase particles formed on the porous membrane by the shear force of the swirling flow.

Abstract: A method of making a polyisobutylene polymer in a recirculating loop reactor with one or more reaction tubes in contact with a heat transfer medium includes controlling the delta P and polymerization reaction to provide a linear velocity of the reaction mixture of at least 11 ft/sec in the one or more tubes of the loop reactor and/or controlling the delta P and polymerization reaction of steps (b) and (c) to provide a recirculation ratio of the recirculation rate to the feed rate of at least 30:1. Typically, the process utilizes a recirculating pump operating at a at a pressure differential of from 35 psi to 70 psi.

Abstract: A rubber composition with disperse phase particles containing poly(phenylene ether) can be formed by a method that includes melt blending an uncured rubber with a poly(phenylene ether) composition containing a poly(phenylene ether) and an oil to form an uncured rubber composition, then curing the uncured rubber composition. Before being blended with the rubber, the poly(phenylene ether) composition exhibits a glass transition temperature of about 40 to about 140° C., and during blending with the rubber, the oil component of poly(phenylene ether) composition migrates from the poly(phenylene ether) composition to the rubber, leaving a poly(phenylene ether)-containing disperse phase that gives rise to a second hysteresis peak temperature of about 160 to about 220° C. as measured by dynamic mechanical analysis of the cured rubber composition.

Abstract: Provided are processes and apparatuses for continuous solution polymerization which can mitigate fouling during the production of propylene-based polymers.

Abstract: A process and the resultant product from the process for continuously making an EPDM utilizing ethylene, propylene, and dienes. This process allows for the creation of products with high diene contents and broad molecular weight distributions while utilizing a continuous flow reactor and a known catalyst. The process allows for these products to be made without gelling, or fouling of the reactor, which are problems known in the art.

Abstract: A process for continuously making a terpolymer or a tetrapolymer utilizing ethylene, an alpha olefin, and at least one polyene. This process allows for the creation of products with high polyene contents and broad molecular weight distributions while utilizing a continuous flow reactor and a known catalyst. The process allows for these products to be made without gelling, or fouling of the reactor.

Abstract: Styrenic (meth)acrylic oligomers that are prepared at lower temperature than conventional solid grade oligomers, or are hydrogenated, contain fewer terminal vinylic unsaturations, when compared to such conventional styrenic (meth)acrylic oligomers prepared by the customary high temperature processes. Styrenic (meth)acrylic oligomers that contain fewer terminal vinylic unsaturations demonstrate improved thermal stability and may provide improved resistance to UV weathering compared to the conventional and non-hydrogenated styrenic (meth)acrylic oligomers.

Abstract: Various methods and systems for removing particulates from a cycle gas stream, e.g., in a reactor system, are provided. In certain embodiments, the methods are performed in conjunction with a polymerization reactor system such as a gas-phase reactor system.

Abstract: The invention relates to a process for operating a mixing kneader, comprising one or more shafts on whose surfaces are disposed kneading bars and which are surrounded by a casing, comprising the following steps: (a) supplying reactants at an addition site in the mixing kneader, (b) converting the reactants in an exothermic reaction, the reaction at first forming a coherent kneadable intermediate, (c) tearing and dividing the coherent kneadable intermediate to form a product, the exothermic reaction optionally continuing during the tearing and division, (d) withdrawing the product at a withdrawal site in the mixing kneader, wherein at least one of the shafts and/or the casing is heated to a temperature above 20° C. during the operation of the mixing kneader.

Abstract: Process and apparatus for discharging polyolefin particles from a gas-phase polymerization reactor of a pressure from 1.0 MPa to 10 MPa to a discharge vessel of a pressure from 0.1 MPa to 1.0 MPa wherein the discharging is carried out discontinuously through at least two discharge lines in which the polyolefin particles are transported horizontally or upwards.

Abstract: The present invention relates to a method for feeding metallocene catalyst slurry to an olefin polymerization loop reactor (1) using a positive displacement device (5) positive displacement device comprising a first chamber and a second chamber, each chamber having an inlet and an outlet and each chamber comprising an ball arranged between the walls of said chamber, wherein said chambers are connected to each other by a pump chamber operably connected to a pump, wherein, the difference between the diameter of said ball and the diameter of said chamber is comprised between 5 to 200 times the average particle size (d50) of said catalyst.

Abstract: Monomer solution and liquid solution immiscible with the monomers in the monomer solution are cocurrently jetted upwardly in a pulsating manner in a reaction vessel. Monomer droplets are allowed to rise up in a controlled and smooth manner under the dynamic forces exerted by differential flow rate and differential pressure between the monomer and liquid solutions and the differential densities between the monomer and liquid solutions without causing coalescence, agglomeration and breakup of the monomer droplets and to stabilize by partial polymerization of the droplets at 50-60° C. The monomer droplets flow out horizontally into a polymerization reactor and get polymerized in the polymerization reactor under agitation at 80-85° C. The polymer beads are dried at 80-100° C. and sieved.

Abstract: Methods and systems for preparing catalyst, such as chromium catalysts, are provided. The valence of at least a portion of the catalyst sent to an activator is changed from Cr(III) to Cr(VI). The catalyst is prepared or activated continuously using a fluidization bed catalyst activator.

Abstract: Apparatus and process for gas phase polymerisation of olefins. The apparatus includes (a) a reaction zone having a grid at its base, (b) an inlet located in the lower half of the reaction zone for introducing a reaction gas to the reaction zone, (c) an outlet located in the upper half of the reaction zone for removing the reaction gas from the reaction zone, and (d) a solids separation unit having an inlet fluidly connected to the outlet for removing the reaction gas from the reaction zone. The inlet of the solids separation unit is located at a vertical height lower than the outlet for removal of reaction gas from the reaction zone and such that the angle to the horizontal of a straight line drawn between the inlet of the solids separation unit and the outlet for removal of reaction gas from the reaction zone is greater than 20°.

Abstract: The invention relates to a process for producing water-absorbing polymer particles with improved permeability, comprising the steps of polymerization, drying, grinding, classification and thermal surface postcrosslinking, with pneumatic conveying between grinding and classification.

Abstract: Provided is a stirred tank polymerization reactor system having a reactor tank, a stirring assembly including a rotatable shaft that extends through a wall of the tank, and a triple barrier mechanical seal. The mechanical seal includes an outer cylinder mounted in the wall of the tank, an inner cylinder that is rotatable relative to the outer cylinder and connected to the shaft, and first, second, and third fluid barrier seals mounted between the outer and inner cylinders at different positions along the axis of rotation of the inner cylinder. First and second sources of pressurized barrier fluid are connected between the first and second pressure fluid barrier seals and the second and third barrier seals, respectively. The three barrier seals advantageously “step down” the differential pressure experienced by the uppermost barrier seals, substantially reducing mechanical stresses experienced by the annular sealing rings and seats.

Abstract: This invention provides an aqueous emulsion, which comprises a polyvinyl alcohol-based resin, as the dispersant, and a polymer comprising a structural unit derived from an ethylenically unsaturated monomer, as the dispersoid, from which a film having excellent transparency can be obtained, and which is excellent in mechanical stability, chemical stability, freezing stability and storage stability, and a method for producing the same, and relates to an aqueous emulsion which has an average particle size of the dispersoid of from 100 to 450 ?m and an apparent grafting efficiency of the polyvinyl alcohol-based resin of from 65 to 75% based on the dispersoid, and a method for producing the same.

Abstract: Described herein are methods for monitoring and restoring electrical properties of polymerization reactor wall films. The method may comprise using a reactor wall monitor to monitor and determine an electrical property, such as the bed voltage or breakdown voltage, of the wall film. The method may further comprise adding continuity additive to the reactor and/or adjusting the feed rate of continuity additive being added to the reactor in response to the measured electrical property.

Abstract: Catalysts and methods for making and using the same are provided. The method for fabricating a catalyst may includes contacting a supported catalyst with a monomer under conditions that reduce an overall charge of the catalyst to less than about 75% of an initial charge of the catalyst. A method for polymerization may include introducing a pre-polymerized catalyst and one or more olefins into a gas phase fluidized bed reactor, operating the reactor at conditions sufficient to produce a polyolefin, wherein the polymerization is carried out in the substantial absence of any continuity additives.

Abstract: Monomer solution and liquid solution immiscible with the monomers in the monomer solution are cocurrently jetted upwardly in a pulsating manner in a reaction vessel. Monomer droplets are allowed to rise up in a controlled and smooth manner under the dynamic forces exerted by differential flow rate and differential pressure between the monomer and liquid solutions and the differential densities between the monomer and liquid solutions without causing coalescence, agglomeration and breakup of the monomer droplets and to stabilize by partial polymerization of the droplets at 50-60° C. The monomer droplets flow out horizontally into a polymerization reactor and get polymerized in the polymerization reactor under agitation at 80-85° C. The polymer beads are dried at 80-100° C. and sieved.

Abstract: A rubber composition with disperse phase particles containing poly(phenylene ether) can be formed by a method that includes melt blending an uncured rubber with a poly(phenylene ether) composition containing a poly(phenylene ether) and an oil to form an uncured rubber composition, then curing the uncured rubber composition. Before being blended with the rubber, the poly(phenylene ether) composition exhibits a glass transition temperature of about 40 to about 140° C., and during blending with the rubber, the oil component of poly(phenylene ether) composition migrates from the poly(phenylene ether) composition to the rubber, leaving a poly(phenylene ether)-containing disperse phase that gives rise to a second hysteresis peak temperature of about 160 to about 220° C. as measured by dynamic mechanical analysis of the cured rubber composition.

Abstract: The invention is directed to a process for the gas phase polymerization of one or more olefin monomers in a fluidized bed reactor in a dry mode or in a (super) condensed mode with a gas stream comprising an inert gas characterized in that the inert gas comprises a mixture of inert components: (1) nitrogen; (2) a gas heat capacity increasing agent (3) a sorption promoting agent and (4) a polymer swelling agent. The inert gas may comprise (1) 5-60% by mol nitrogen (2) 10-90% by mol ethane (3) 1-50% by mol % n-butane and (4) 0.1-10% by mol % n-pentane or iso-pentane.