WO2004004880A2

WO2004004880A2 - Method and apparatus for processing flowable material and polyhipe polymers

Info

Publication number: WO2004004880A2
Application number: PCT/GB2003/002972
Authority: WO
Inventors: Galip Akay
Original assignee: Galip Akay
Priority date: 2002-07-09
Filing date: 2003-07-09
Publication date: 2004-01-15
Also published as: AU2003251326A1; WO2004004880A3; EP1526914A2; GB0316063D0; GB0215833D0; GB2393438A

Abstract

A method and apparatus for processing flowable material is described in which a first surface on a rotor faces a second surface on a stator. The first and second surfaces have indentations therein and the rotor is rotated relative to the stator so as to mix and/or granulate and/or encapsulate the flowable material. Functionalised (eg sulphonated, phosphated or nitrated) polyHIPE polymers and their salts are also described, as is a process for preparing the functionalised polyHIPE polymers and their salts. Uses for these polyHIPE polymers are further described, these including the separation of oil and water from an oil/water emulsion (eg oil-in-water and water-in-oil emulsions), as water absorbers, as growth media in promoting the growth of plants or crops and in separating gas/liquid mixtures.

Description

Method and apparatus for processing flowable material and PolyHIPE polymers

The present invention relates to a method and apparatus for processing flowable material, and relates particularly, but not exclusively, to a method and apparatus for of mixing and/or granulating and/or encapsulation. The invention also relates to a method and apparatus for separating the component liquids of an emulsion, and relates particularly, but not exclusively, to a method and apparatus for separating oil- water emulsions and gas/liquid mixtures. The present invention further relates to functionalised (eg sulphonated, phosphated or nitrated) polyHIPE polymers and their salts, to a process for preparing functionalised polyHIPE polymers and their salts and to the use of functionalised polyHIPE polymers and their salts in the separation of oil and water from an oil/water emulsion (eg oil-in-water and water-in-oil emulsions), as water absorbers, as growth media in promoting the growth of plants or crops and in separating gas/liquid mixtures.

Mixing and granulation are important aspects of many industries involved in the processing of powders. For example, in the pharmaceutical, detergent, fertiliser food and coating industrial sectors, the uniform mixing of the components in a powder mixture is important in order to maintain uniform product supply. The conversion of powders into a granular form is of particular benefit in order to assist in the safe handling of such materials. It is also common to encapsulate granulated products in order to control the release of the encapsulated product and to protect the product from attrition.

Known techniques of producing granules from powder include tumbling, agitating or fhiidising raw materials in the presence of liquid binders. However, these techniques produce a wide distribution of granule size. Alternatively, materials may be forced to flow through dyes or screens followed by cooling to obtain granules. Further known techniques for agglomeration of powders into granules are described in European Patent publication numbers EP0303416 and EP0382464, which are based on the flow induced phase inversion technique described in EP0649867. A schematic representation of such an agglomeration technique is shown in Figure 1. In this example, a molten polymer 10 is mixed with primary particles 12 to produce a mixture 14. During the process of mixing and cooling of mixture 14, further primary particles or a crumbling agent 16 are added. The flow induced phase inversion occurring during this mixing and cooling step results in the production of large micro- capsules 18. These large micro-capsules 18 may be comminuted into the granular smaller micro-capsules 20.

These granulation techniques suffer from the disadvantage that the mixing of the molten polymer and primary particles may not be complete in the sense that the mixture is insufficently uniform. Furthermore, the particle sizes produced are not of sufficiently uniform dimensions, and therefore a comminution stage, in the form of milling, is often needed to reduce the particle size. The uneven particle size results from the difficulties in producing evenly distributed cooling within a large mass of material.

In crude oil extraction, water is demulsified in crude oil. The amount of water may be between 10-90%. To separate water and oil, the emulsion must be broken down, demulsified, in the first instance. There are very many other examples of emulsions produced through industrial processes. In these circumstances, it is known to use a demulsifier to break down the emulsion. An example of sμch a demulsifier is described in International Patent^' publication number WO 02/10070 in which a micro- porous polymer, known as a PolyHIPE polymer is used as an emulsifier absorber. In this process a small amount of demulsifier (approximately 0.1 grams of demulsifier per kilogram of emulsion) is mixed with the emulsion and allowed to settle prior to separation. As a result, the demulsification process is considerably accelerated and oil-water separation time is reduced. However, it is difficult to convert this process into a continuous separation process in industrial scale. Furthermore, the necessity to mix the demulsifier into the emulsion must be undertaken with care in order to prevent the droplet size of the emulsion to be decreased by over- vigorous mixing.

Mixing and separation of products and unreacted chemicals are also important in many chemical and biochemical processes. If the viscosity of the reaction medium is low, reaction can proceed rapidly without any special consideration to mixing. However, when the reaction medium is highly viscous, then effective mixing is necessary in order to accelerate the reaction and to have high yield. Rotating (spinning) single disks reactors are now used to enhance the heat transfer to the reaction media. These reactors form a thin liquid layer to enhance the heat and mass transfer processed. However such spinning single disks cannot be used when the fluid viscosity is large or the reaction media has particulate matter. In situ separation of all or some of the reactants is also desirable for the same reasons. Thus, the present invention can address these problems in large scale continuous processes.

Mixing of small quantities of one component in another major component in uniform manner on industrial scale is also difficult.

Materials which can absorb and retain large volumes of water in the presence of electrolytes are used as growth media in promoting the growth of plants or crops. The basic function of such growth media is to regulate the water available to the plant. However, they may also provide support for the plant and distribute air, water and nutrients with consistent chemical characteristics. Hydroponic culture is a means of intensive crop production carried out indoors or outdoors where there are restrictions on availability of water or land, climatic restrictions, requirements for pesticide free growth or plant specific growth media, nutrient and irrigation. In hydroponic culture, soil is substituted wholly by a growth media (eg a microporous growth media) which may be periodically disinfected using steam,. ^'solarisation or flooding to avoid the need for pesticides. The requisite weight of microporous growth media is several fold less than that of soil. However there is in general a need for an inexpensive microporous growth media to complement the energy intensive hydroponic production.

Commonly used plant growth media are either microporous materials (eg perlite, vermiculite, expanded (hydrophobic) polystyrene) or cross-linked water soluble polymers. In microporous materials, the water holding capacity is attributable to the capillarity and available pore volume. Currently, the most widely used growth media is expanded perlite which is obtained from heat treatment (at 870°C) of volcanic rock which contains silicone, aluminium, potassium and sodium as the main constituents. Depending on the heat treatment procedure, expanded perlite may absorb two to six times its own weight of water. Relatively low water holding capacity and presence of aluminium are the disadvantages of perlite as growth media. The fastest growing application of perlite is in hydroponic culture due to its water/nutrient regulation properties.

Crosslinked water soluble polymers such as potassium polyacrylate/polyacrylamide copolymers absorb several hundred times their own weight of water by swelling during hydration. However, in the presence of electrolyte (eg fertilizer) the water holding capacity is reduced. Furtheimore, these crosslinked polymers are mechanically weak and they can be generally expected to last about five years when mixed with soil and peat. These crosslinked polymers form a continuous gel which can prevent aeration and so are generally not used in hydroponic plant cultures.

WO-A-02/ 10070 discloses a method for the separation of oil and water from oil/water emulsions using as a demulsifier a microporous polymer known as a sulphonated polyHIPE polymer (PHP). A small amount of the sulphonated demulsifier (approximately 10^" kg demulsifier per kg emulsion) may be mixed with the emulsion in a rotating disk reactor and allowed to settle for separation. Alternatively the disks of the rotating disk reactor may be composed at least partly of a demulsifying polyHIPE polymer itself. In this case, the polyHIPE polymer is usefully rendered hydrophilic (and therefore water absorbent) by sulphonation.

Known processes for rendering polyHIPE polymers hydrophilic involve sulphonation or nitration. These processes are long and expensive. For example, sulphonated polyHIPE polymers may be prepared in. the first instance by obtaining an oil phase containing (as the main components) a styrene monomer and a cross-linking agent (divi yl benzene) together with a surfactant (Span 80) and an aqueous phase comprising an. aqueous solution of a polymerisation initiator (usually potassium persulphate). After formation of the water-in-oil high internal phase emulsion in which the volume of the dispersed aqueous phase may be as high as 97-98%, the temperature is increased to 60°C and polymerisation is initiated. After completion of polymerisation and cross-linking, the internal phase is evaporated and the polymer is dried at 100°C. The polyHIPE polymer is copped and pieces are immersed in excess concentrated sulphuric acid. The temperature is raised to 60°C or more for a prescribed length of time to achieve the desired level of sulphonation. If the particles are too large (eg 1cm in diameter) the penetration of the acid into the pores is lengthy. The reason for this is that sulphonation starts from the exterior causing the large particles to swell which make the interconnecting holes smaller thereby reducing the penetration of the acid into the interior. This causes the formation of a hydrophilic skin with a hydrophobic core. After sulphonation, excess acid is washed away and the polymer is dried. This is less than straightforward and several washing cycles are typically required. Whilst it may be possible to obtain fairly uniformly sulphonated polymer as a powder in which the diameter of the sulphonated particles is lcm or less, it is not possible to obtain uniformly sulphonated polymer in bulk. As the size of the pores is decreased, sulphonation becomes more difficult.

Preferred embodiments of the present invention seek to overcome the above described disadvantages of the prior art. The present invention also seeks to improve functionalisation of polyHIPE polymers by exploiting in the formation of the high internal phase emulsion a functionalising agent in the dispersed phase. More particularly the present invention relates to a process for preparing in bulk functionalised polyHIPE polymers exhibiting a substantially uniform degree of functionalisation using an aqueous solution of a functionalising agent in the foimation of the high internal phase emulsion.

According to an aspect of the present invention, there is provided an apparatus for processing flowable material, the apparatus comprising:

at least one first member having a respective first surface provided with a plurality of first indentations;

at least one second member rotatable relative to at least one respective first member and having a respective second surface provided with a plurality of second ^■ indentations, wherein at least one second surface faces a corresponding first surface to define a respective cavity for receiving flowable material; and

at least one first inlet for introducing at least one first flowable material into at least one said cavity. By providing an apparatus with a second member which is able to rotate relative to at least one first member and the first and second members both having indentations in facing surfaces, the advantage is provided that if a molten material is introduced into the cavity between the members, as rotation occurs between these members and the molten or partially-molten material solidifies, granules are formed. In particular, the granules formed by this apparatus are of substantially consistent dimensions. Furthermore, if the flowable material is a mixture of compounds, for example a solid within a molten polymer, the mixture between the solid and the polymer becomes significantly more uniform than in other techniques. As a result, the uniformly sized and mixed granules will contain equal or at least predictable quantities of the component parts of the mixture. This consistent mixing and granular production is of particular importance and is produced more efficiently than in the apparatus of the prior art.

The apparatus may further comprise insertion means for introducing at least one said first flowable material into at least one said cavity under pressure.

By introducing the first flowable material under pressure, the apparatus is able to work as a continuous flow, constantly producing granules from the introduced first flowable material.

Said insertion means may comprise at least one extruder.

The apparatus may further comprise field induction means for inducing a field between at least one said first member and at least one said second member.

By applying a field, in particular a field of the type set out below, the advantage is provided that characteristics of the mixing and agglomeration/granulation occurring within the apparatus may be altered.

In a preferred embodiment, said field induction means induces a thermal field.

In another preferred embodiment, at least a portion of the or each said first member is at a temperature below the melting point of at least one said first flowable material and at least a portion of the or each said second member is at a temperature below the temperature of said portion of said first member.

By introducing a molten material into the apparatus and by having the surface of one member at a temperature just below the meltmg point of the molten material and the second member at a temperature slightly lower still, the advantage is provided that as the material begins to solidify and passes from the indentations of one member to the other, it is gently heated and cooled, the cooling component being more dominant than the heating as the mixture cools towards it crystalisation temperature. It is this heating and cooling that results in the formation of the granules, with uniform size.

In a preferred embodiment, said field induction means induces an electrical field.

In a preferred embodiment, said field induction means induces a ultrasonic field.

In a preferred embodiment, said field induction means induces a field which differs radially along said first member and/or said second member.

By altering the fields radially, for example the temperature of the first and/or second member, reducing or increasing as the first flowable material moves radially outwards, the advantage is provided that further control over the granulation process can be applied.

In a preferred embodiment, said first member and/or said second member is hydrophilic.

In a preferred embodiment, said first member and/or said second member is hydrophobia

In a preferred embodiment, a plurality of said indentations in at least one said first surface are out of phase wjth a plurality of said indentations in the corresponding second surface in directions' adial to said axis of rotation. By providing the indentations of the first surface out of phase with the indentations of the second surface, the advantage is provided that the rotation of the first or second member cause the pumping of the material radially from one indentation in one surface to a radially outwards indentation in the next surface. Furthermore, this formation of indentation applies both shear and extentional deformation forces to the material thereby producing efficient mixing of this apparatus. In particular, the shear deformation provides macro-mixing and the extentional deformation provides micro- mixing. The relative magnitudes of the shear and extentional deformation can be controlled by the relative positions of the indentations in the first and second surfaces. For example, by minimising the overlap between the indentations in the first and second surfaces will cause the flowable material to expand into a cavity after being sheared between the clearance produced by the flat surfaces (i.e. land). If the cavities do not overlap, material will be transferred from cavity to cavity without significant expansion.

In a preferred embodiment, at least one said first or second surface is substantially circular in a direction transverse to an axis of rotation.

In a preferred embodiment, at least one said first member is provided with a plurality of said first surfaces.

In a preferred embodiment, at least one said first ^'inlet is arranged adjacent an axis of rotation of at least one said second member relative to the corresponding said first member.

In a preferred embodiment, at least one second inlet is arranged radially outwards from an said first inlet.

In another preferred embodiment, -at least one said second inlet introduces at least one second flowable material into at least one said cavity.

By introducing a second flowable material into an inlet radially outwards from the first inlet, the advantage is provided that the second flowable material will tend to encapsulate the partially or fully formed granules of the first flowable material. In a preferred embodiment, the separation between at least one said second member and the corresponding said first member is adjustable.

The particle size produced by the apparatus is largely dependent upon the separation between the first and second members. As a result, making the separation between the members adjustable allows control of the size of particle produced.

In a preferred embodiment, at least one of said first or second surface comprises at least one porous surface.

In another preferred embodiment, at least one said porous surface comprises at least one micro-porous surface.

In a further preferred embodiment, at least one micro-porous surface comprises at least one micro-porous polymer.

hi a preferred embodiment, at least one said micro-porous polymer comprises at least one sulphonated micro-porous polymer.

In a preferred embodiment, at least one said first or second surface is metallic.

In a preferred embodiment, at least one said first or second surface is metallic but rendered hydrophobic through coating with silane coupling agents.

According to another aspect of the present invention, there is provided an apparatus for processing flowable material, the apparatus comprising:

at least one second member rotatable relative to at least one respective first member and having a respective second surface comprising at least one porous surface, wherein at least one second surface faces a corresponding first surface to define a respective cavity for receiving flowable material and said porous surface allows a first component of said flowable material to be separated fi-om a second component of said flowable material; and

at least one first inlet for introducing flowable material into at least one said cavity.

By providing an apparatus in which a first and second member are arranged such that one or both are rotatable with respect to the other and the first member is formed with indentations therein and the second member is formed from a porous material, the advantage is provided that an emulsion of, for example a water-in-oil emulsion and water, may be separated with surprising efficiency. In particular crude petroleum oil- water emulsions or effluent emulsions can be further processed to separate oil and water.

In a preferred embodiment, said second surface provided with a plurality of second indentations.

By providing the second surface with second indentations, the advantage is provided that the increased mixing from the additional indentations increases the mixing efficiency of the demulsifier with the emulsion in the first place. Once the demulsification has taken place, the disengagement of the oil and water phases is efficiently performed when oil appears from the hydrophobic top element and water from the hydrophilic lower element.

The apparatus may further comprise insertion means for introducing flowable material into at least one said cavity under pressure. The apparatus may further comprise field induction means for inducing a field between at least one said first member and at least one said second member.

In a preferred embodiment, said field induction means induces a thermal field.

In a prefeired embodiment, said field induction means induces a field which differs radially along said first member and/or said second member.

By providing a first or second member that is hydrophilic, the advantage is provided that this will improve separation of the water.

In a preferred embodiment, said first member and/or said second member is hydrophobic.

By providing a first or second member that is hydrophobic, the advantage is provided that this will improve the separation of the oil.

In a preferred embodiment, said indentations in the or each said first surface are out of phase with said indentations the respective second surface.

In a prefeired embodiment, at least one said first or second surface is substantially circular in a direction transverse to an axis of rotation.

In a prefeired embodiment, at least one said first member is provided with a plurality of said first surfaces. In a preferred embodiment, at least one said first inlet is arranged adjacent an axis of rotation of at least one said second member relative to the coiresponding said first member.

In a preferred embodiment, the separation between at least one said second member and the corresponding said first member is adjustable.

In a prefeired embodiment, at least one said first or second surface is metallic.

According to a further aspect of the present invention, there is provided a method of processing flowable material, the method comprising the steps of:-

introducing a first flowable material into at least one cavity defined between a first surface of a first member, and a second surface of a second member, the first and second surfaces having respective indentations therein adapted to receive said flowable material; and

rotating at least one said second member relative to the corresponding said first member so as to process said material.

In a prefeired embodiment said process is granulation and/or mixing and/or drying and/or chemical reaction.

By heating the first or second member, introducing a granular material mixed in a solvent and drawing the vaporised solvent off through a porous first or second member, the advantage is provided that an efficient compact drier can be used to dry granules without them drying into clumps.

According to a further aspect of the present invention, there is provided a method- of processing flowable material, the method comprising the steps of:-

introducing a first flowable mixture of materials into at least one caλάty defined between a first surface of a first member, and a second surface of a second member, the first surfaces having indentations therein adapted to receive said flowable mixture of materials and the second surface comprising at least one micro-porous polymer.

In a prefeired embodiment said process is separation.

Viewed from an aspect the present invention provides a process for preparing a functionalised polyHIPE polymer comprising:

(a) obtaining in a first phase a polymerisable component, said polymerisable component comprising a functionalisable moiety;

(b) obtaining in a second phase a functionalising agent;

(c) forming a high internal phase emulsion of the first phase and the second phase, wherein the first phase and the second phase are immiscible;

(d) causing polymerisation of the polymerisable component into a polyHIPE polymer; and

(e) causing functionalisation of at least a proportion of the functionalisable moieties of the polyHIPE polymer.

The process of the invention is advantageously carried out in a relatively small number of steps (ie the process dispenses with a number of the steps which characterise the conventional process). For example, by using small amounts of sulphuric acid it is possible to achieve reliable sulphonation with less waste acid and consequently easier washing of the product.

Preferably the first phase is continuous and the second phase is dispersed. The continuous phase may be a non-aqueous phase. The dispersed phase may be an aqueous phase. Preferably the continuous (non-aqueous) phase is an oil phase and further comprises a surfactant (eg Span 80).

Preferably the phase volume of the second (dispersed) phase in the emulsion is in the range 70-95%, particularly preferably 80-95%.

The term "polymerisation" herein is intended to include one or more of linear or branched polymerisation, linear or branched copolymerisation and cross-linking (or combinations thereof). The polymerisable component may be one or more of the group consisting of high or low molecular weight, natural or synthetic monomers, co-monomers, oligomers, co- oligomers, macromonomers, polymers, co-polymers and mixtures thereof. The term monomer/co-monomer is intended to cover single monomer/co-monomer units or a block of repeating monomer/co-monomer units (such as a dimer or trimer).

The functionalisable moiety may be selected from the group consisting of an optionally substituted unsaturated acyclic moiety, an unsaturated monocyclic or polycyclic (eg fused polycyclic) hydrocarbon (eg carboaromatic) moiety which is optionally ring substituted and an unsaturated monocyclic or polycyclic (eg a fused polycyclic) heterocyclic (eg hetero aromatic) moiety which is optionally ring substituted. Optional substituents may be chosen to enhance the electronic (or other) properties of the moiety (eg a substituent which has an electron withdrawing or donating effect).

By way of example, the polyHIPE polymer may be a polyvinyl, polyaryl, polyheterocycle (eg polyheteroaryl), oligoaryl (eg oligoheteroaryl) or oligoheterocycle-based polyHIPE polymer.

Where the polyHIPE polymer is a polyheterocycle or oligoheterocycle-based polyHIPE polymer, the functionalisable moiety is preferably an optionally ring substituted heterocyclic moiety (such as a 5- or 6-membered^' optionally ring substituted heterocyclic moiety), particularly preferably an optionally ring substituted hetero aromatic moiety. The optionally ring substituted heterocyclic moiety may contain one, two or three heterocyclic atoms which may be the same or different. Preferably the (or each) heterocyclic atom is selected from the group consisting of nitrogen, sulphur, oxygen, phosphorous and selenium, preferably the group consisting of nitrogen, oxygen and sulphur, particularly preferably the group consisting of nitrogen and sulphur. By way of example, the optionally ring substituted heterocyclic moiety may be selected fi-om the group consisting of optionally ring substituted thiophene. furan, pyridine, imidazole, isothiazole, isooxazole, pyran, pyrazine, pyridazine, pyrazole, pyridine, pyrimidine, triazole, oxadiazole, pyrrole, indazole, indole, indolizine, pyrrolizine, quinazoline and quinoline. Where the polyHIPE polymer is a polyaryl or oligoaryl-based polyHIPE polymer, the functionalisable moiety is preferably an optionally ring substituted carbo aromatic moiety (or aryl moiety). For example, the functionalisable moiety may be selected from the group consisting of an optionally ring substituted phenyl, benzyl, anthracenyl, phenanthrenyl and napthalenyl moiety. Preferably the functionalisable moiety is an optionally ring substituted phenyl moiety (eg an o- ox ^-substituted phenyl moiety). The phenyl moiety may be ring substituted (eg o- or _/^-substituted) with a group which enhances its electronic properties (preferably a group which has an electron donating effect). A particularly preferred optionally ring substituted phenyl oiety is an optionally ring substituted styryl moiety (eg an o- or -substituted styryl moiety).

In a preferred embodiment, the polymerisable component comprises a styrene monomer or a styrene co-monomer and a cross-linking agent. A preferred styrene co- monomer is a styrene/alkyl alkylacrylate co-monomer (wherein each alkyl group is independently selected from the group consisting of a linear, branched or cyclic Cι_-6- alkyl group such as methyl, ethyl, propyl, isopropyl, butyl isobutyl, pentyl or hexyl). Particularly preferred is a styrene/ethyl hexylacrylate co-monomer which provides an advantageously flexible hydrocarbon chain (see EP-A-0239360).

The cross-linking agent may be selected from the group consisting of proteins, silicates, monomers, co-monomers, oligomers, co-oligomers, macromonomers, polymers and co-polymers. Specific examples include divinyl benzene, eurylene diacrylate, N-N'-diallyltartardiamine, N-N'(l,2 dihydroxyethane)-bis-acι-ylamide and N-N'-N"-triallyl citrictriamide. Prefeired is divinylbenzene. Amine containing cross- linking agents (or monomers) are useful in the immobilisation of enzymes.

The functionalising agent may be adapted to functionalise the polyHIPE polymer with a functional group selected fi-om:

OR, COOR, COSR, COR, COO(COR), SR, SSR, BHal₂, B(OH)₂, NR₂, NRNR₂, NR₃ ⁺, CONR₂, CHO, F, CI, Br, I, CN, NO, N0₂, P(O)₂ H₂, P(O)₃H, P(0)₄, P(0)(OR)H₂, P(0)(OR)₂H, S(0)₂ORand S0₄ (wherein each R is independently H;

Hal; a metal species (such as a metal ion eg an alkali metal or alkaline earth metal ion); or an optionally hydroxylated or alkoxylated, linear or branched, saturated or unsaturated C_1-12-alkyl group (preferably Cι_-6-group) optionally interrupted by or terminating in one or more cyclic (eg monocyclic) hydrocarbon (eg aromatic hydrocarbon) groups, acyclic heteroaromatic groups (such as oxygen or nitrogen) or heterocyclic (eg heteroaromatic) groups).

The functionalised polyHIPE polymer is preferably hydrophilic. Thus the functionalising agent is preferably adapted to render the polyHIPE polymer hydrophilic. For this purpose the functionalising agent is adapted to functionalise the polyHIPE polymer with a polar functional group (eg a polar functional group from those listed above). Particularly preferred polar functional groups are N0₂ and S(0)₂OH.

The functionalising agent may contain (or be capable of releasing) an electrophile such as F⁺, Cl⁺, Br⁺, Ϋ, NO⁺, N0₂ ⁺, HS0₃ ⁺, RCO⁺, RS0₃ ⁺, BHal₂ ⁺ (eg BC1₂ ⁺) or B(OH)₂ ⁺ (wherein R is as hereinbefore defined). These may be prepared in a manner familiar to those skilled in the art.

Preferred functionalising agents are water soluble. Particularly preferably the functionalising agent is a water soluble acid such as a strong organic acid (eg an aliphatic or aromatic acid such as a carboxylic acid) or an acid derivative thereof (such as an acid chloride) or a mineral acid. Although it may be desirable that the amount of acid is in excess, there may (in practice) be an upper limit to the concentration of acid in the second (aqueous) phase which (if it is exceeded) causes the emulsion to become unstable resulting in no foimation of polyHIPE polymer.

Prefeired is an acid of formula

X[H]_p[0]_n[OH]_m (wherein X is S, N, P or an optionally hydroxylated or alkoxylated, linear or branched, saturated or unsaturated Cj-ι₂-alkyl group (preferably Cι_-6-group) optionally interrupted by or terminating in one or more cyclic (eg monocyclic) hydrocarbon (eg aromatic hydrocarbon) groups, acyclic heteroaromatic groups (such as oxygen or nitrogen) or heterocyclic (eg heteroaromatic) groups; p is 0, 1 or 2; m is 1, 2 or 3; and n is 1 or 2).

Preferably p is 0.

Preferably X is S, N or P.

Particularly preferred acids are sulphuric acid, nitric acid and phosphorous oxoacids (including H P0₄, H P0₃ and H₃P0 but preferably H P0 ), more preferably sulphuric acid and nitric acid, most preferably sulphuric acid.

Preferably the functionalising agent is a sulphonating agent. Typically the sulphonating agent is one which carries or which may be induced to release sulphur trioxide. An example is l-protopyridinium sulphonate or sulphuric acid.

A prefeired sulphonating agent is sulphuric acid. Dilute sulphuric acid is particularly preferred. Generally speaking, the amount of sulphuric acid present in the second (aqueous) phase is such as to achieve a desired degree of sulphonation of the polyHIPE polymer. Typically if the amount of sulphuric acid is about 25wt% or less of the second (aqueous) phase (or a molar equivalent thereof), a stable emulsion is obtained with excess acid. If no excess acid is desirable, the amount of sulphuric acid is generally 10wt% or less (eg 5-10%) of the second (aqueous) phase (or a molar equivalent thereof).

Preferably the functionalising agent is a nitrating agent. A preferred nitrating agent is nitric acid. Nitric acid is generally used in the presence of a strong acid such as sulphuric acid, HC10 or HF/BF . Preferably the functionalising agent is a mixture of nitric and sulphuric acid (typically used at low temperature). Typically if the concentration of nitric acid is about 15wt% or less of the second (aqueous) phase (or a molar equivalent thereof), a stable emulsion is obtained.

In one embodiment, after step (d) the sulphuric acid in the polyHIPE polymer is heated to below the sulphonation temperature to evaporate water and nitric acid is added (usually after cooling to for example 0°C). Step (e) may then be performed at low temperature (eg 25°C).

A preferred phosphating agent is phosphoric acid. Dilute phoshproc acid is particularly preferred. Generally speaking, the amount of phosphoric acid present in the second (aqueous) phase is such as to achieve a desired degree of phosphation of the polyHIPE polymer. Typically if the concentration of phosphoric acid is about 25wt% or less of the second (aqueous) phase (or a molar equivalent thereof), a stable emulsion is obtained.

The functionalising agent may be an acylating agent. Typically the acylating agent is a Friedel-Krafts reagent such as a carboxylic acid anhydride or chloride in the presence of a Lewis acid catalyst such as A1C1₃.

From a practical point of view, excess acid may result in the formation of coalescence pores which are obtained when the primary pores coalesce during polymerisation. Thus when a high concentration of acid is used in the process of the invention, step (d) is preferably carried out whilst shaking (preferably until a viscous gel is formed).

Any excess acid may be desirably exploited in a further step of the process of the invention (such as in in situ formation of a salt ie a salt formed in the microporous structure of the functionalised polyHIPE polymer). In a prefeired embodiment, the process of the invention further comprises:

(f) converting excess acid into an in- situ salt.

The salt may be prepared in situ in step (f) by adding to the functionalised polyHIPE polymer a metal containing species (eg an alkali metal or an alkaline earth metal containing species). Preferred is a potassium, sodium or magnesium containing species (eg an alkali such as sodium, potassium or magnesium hydroxide). The conversion to a salt may be in general achieved in a manner familiar to those skilled in the art with conventional reagents.

It may be possible to effect controlled release of the in situ salt. Preferably the in situ salt is a nitrate, sulphate or phosphate salt which can be useful when released slowly to fertilise plants. Slow release may be achieved by a hydrophobic barrier (for example).

The functionalised polyHIPE polymer may itself of course additionally or alternatively be converted into a functionalised polyHIPE polymer salt.

Step (e) may be carried out thermally or chemically. In a preferred embodiment, step (e) comprises: causing functionalisation of the polyHIPE polymer thermally.

For example, functionalisation may be caused by elevating the temperature from the polymerisation temperature to a functionalisation temperature. Typically, the functionalisation temperature is in excess of 100°C (eg in the range 150 to 170°C such as for sulphonation for example).

In general for sulphonation, the degree of sulphonation is dependent on the acid concentration, the sulphonation temperature and the duration of sulphonation at that temperature. Sulphonation may be initiated by elevating the temperature from the polymerisation temperature to a sulphonation temperature. Typically, the sulphonation temperature is in excess of 150°C (eg 150 to 170°C, preferably about 160°C) which causes the removal of excess water thereby achieving sulphonation (eg through release of sulphur trioxide).

Step (d) may be carried out thermally and/or chemically. For example, the temperature of the emulsion may be elevated to a polymerisation temperature. Typically, the polymerisation temperature is 60°C or more. Where step (e) is carried out thermally, the polymerisation temperature in step (d) should not exceed the functionalisation temperature. For the purposes of carrying out step (d) chemically, the first (eg non-aqueous) phase or the second (eg aqueous) phase may contain a polymerisation initiator. For example, an aqueous phase may include sodium or (preferably) potassium persulphate or a non- aqueous phase may contain azobisisobutyronitrile or 1,1- azobis(cyclohexanecarbonitrile) .

Step (d) may be followed by additional chemical steps such as inter alia condensation steps and by homogenisation (eg by agitation). Additives may be added to the first (eg non-aqueous) phase (for example to achieve coalescence if desired).

In a preferred embodiment, step (c) comprises:

(cl) dosing the second phase into the first phase.

Dosing rates are discussed in WO-A-00-34454.

Step (c) may comprise:

(c2) mixing the second phase into the first phase (eg using a batch mixer).

Step (c2) may be carried out for example by stirring for a period sufficient to ensure complete emulsification. A period of 20 minutes may suffice. Step (c2) may be carried out at an elevated temperature.

In a preferred embodiment, the process of the invention further comprises: moulding the functionalised polyHIPE polymer into a desired shape (eg a porous disk) using a mould.

The process of the invention may advantageously lead to functionalised (eg sulphonated) polyHIPE polymer in bulk with substantially uniform functionalisation (eg sulphonation). For example, relatively large blocks of substantially uniformly functionalised (eg sulphonated) polyHIPE polymer (eg >lcm diameter) may be obtained. Other forms such as particulate, powder, monolithic or membrane forms may be prepared if desired. If the functionalised (eg sulphonated) polyHIPE polymer is required in particulate form, step (e) is preceded by: dividing (eg chopping) particles of the polyHIPE polymer.

Alternatively if the functionalised (eg sulphonated) polyHIPE polymer is required in particulate form, step (d) comprises:

(d') comminuting the gelation formed shortly after adding the first and second phase together; and

(d' ') mixing (eg gently mixing) the gelation to cause polymerisation.

Typically step (d') is carried out before a solid rigid polymeric structure has been formed by polymerisation in step (d").

By providing functionalised polyHIPE polymer in bulk with substantially uniform functionalisation, the invention is further independently patentably significant.

Viewed from a further aspect the present invention provides substantially uniformly functionalised polyHIPE polymer or a salt thereof in bulk.

Preferably the substantially uniformly functionalised polyHIPE polymer or salt thereof is obtainable by a process as hereinbefore defined.

Preferably the substantially uniformly functionalised polyHIPE polymer or salt thereof is hydrophilic.

Preferably the substantially uniformly functionalised polyHIPE polymer or salt thereof is a substantially uniformly phosphated, nitrated or (preferably) sulphonated polyHIPE polymer or a -salt thereof

Preferably the substantially uniformly functionalised polyHIPE polymer or salt thereof has a pore size typically in the range 20-5 OOμm (for coalescence pores). Preferably the substantially uniformly functionalised polyHIPE polymer or salt thereof has an interconnect size typically in the range 5-1 OOμm.

Preferably the substantially uniformly functionalised polyHIPE polymer or salt thereof has a porosity typically in the range 70-95%.

The substantially uniformly functionhsed polyHIPE polymer or salt thereof may have a degree of functionalisation in excess of 12% of the available functionalisable moieties. Typically the degree of functionalisation is in the range 20-95%.

It has been found that the functionalised polyHIPE polymers of the present invention usefully separate liquid hydrocarbons from gas (eg gas streams produced after the gasification of biomass or fossil fuel waste or combinations thereof).

Viewed from a yet further aspect the present invention provides a method for isolating a liquid from a gas in a liquid-gas mixture, said method comprising: contacting the liquid-gas mixture with a functionalised polyHIPE polymer as defined hereinbefore.

The liquid may be a liquid hydrocarbon (eg tar such as tar produced after the gasification of biomass or fossil fuel waste or combinations thereof). The gas may be a gas stream produced after the gasification of biomass or fossil fuel waste or combinations thereof (eg a gas containing one or more of carbon monoxide, hydrogen, methane, nitrogen and carbon monoxide).

Typically the liquid-gas mixture is contacted with the functionalised polyHIPE polymer by passing it through an appropriate form, of the functionalised polyHIPE polymer. Moisture and particulates (such as ash) may also be usefully removed fi-om the gas stream.

The use of functionalised polyHIPE polymers in gas/liquid separation can be further intensified and made practical by incorporating the polymers into gas blowers and compressors. For example, the polymers may be incorporated into a barrier wall at or near- to the exit(s) of the gas blower or compressor. Preferably for this aspect of the invention the functionalised polyHIPE polymer is a sulphonated polyHIPE polymer. Particularly preferably for this aspect of the invention the sulphonated polyHIPE polymer is in particulate, monolithic block or packed bed form.

Preferably for this aspect of the invention the functionalised polyHIPE polymer is a functionalised styrene/ethyl hexylacrylate polyHIPE co-polymer which benefits from being elastic.

Preferably for this aspect of the invention the pore size of the functionalised polyHIPE polymer is in the range 50-100 microns (ie relatively large).

Viewed from an even further aspect the present invention provides use of a functionalised polyHIPE polymer as hereinbefore defined as a demulsifier.

A prefeired embodiment is use of a functionalised polyHIPE polymer as a demulsifier in the separation of an aqueous and non-aqueous phase of an aqueous/non-aqueous phase emulsion (eg the separation of oil and water from an oil in water or water in oil emulsion).

This aspect of the invention may be beneficial in inter alia. ^'offshore oil extraction, pharmaceutical or chemical manufacture, biotechnology and the nuclear fuel industiy.

Viewed fi-om an even yet further aspect the present invention provides a gas blower or compressor wherein at least one wall is at least partly composed of or coated with a functionalised polyHIPE polymer as hereinbefore defined.

Viewed from a still further aspect the present invention provides use of a hydrophilic functionalised polyHIPE polymer as hereinbefore defined as a water absorber.

In terms of water absorbtion, the hydrophilic functionalised polyHIPE polymers of the present invention ma}' have the desirable properties of conventional microporous expanded perlite and of cross-linked, water soluble polymers but are mechanically strong with a controllable interconnected microporous structure which can swell in a controlled manner so as to absorb water typically about 40 to 100 times its own weight. In the absence of swelling, 90% void volume polymer will absorb water at about nine times its own weight. The water holding capacity of these materials may be controlled by changing the phase volume, pore size, degree of cross-linking and degree of functionalisation (eg sulphonation/nitration) in a manner familiar to those skilled in the art. Their mechanical strength and biodegradability may also be controlled.

By virtue of their utility as water absorbers and ability to effect controlled release of functional groups, the hydrophilic functionalised polyHIPE polymers may be used in commercial agriculture and horticulture, landscaping, reforestation, land reclamation, plant transportation/storage and sports turf and golf courses. For example, the hydrophilic functionalised polyHIPE polymers contribute to water conservation/regulation and in seeking to reduce the frequency of irrigation, temperature regulation (insulation), aeration of soil, increased shell life of plants, reduced transplant shock (high survival rate), reduced leaching of nutrients, enhanced growth rate, delivery of plant starter fertiliser and reduced turf compaction and damage. In other words, the hydrophilic functionalised polyHIPE polymers of the invention are useful growth media.

Viewed from an. ^'even still further aspect the present invention provides use of a hydrophilic functionalised polyHIPE polymer as hereinbefore defined as a growth medium.

Viewed from a yet even still further aspect the present invention provides use of a hydrophilic functionalised polyHIPE polymer as hereinbefore defined as an ion exchange medium or in bioremediation.

The open pore structure of the hydrophilic functionalised polyHIPE pofymers gives them a desirably high rate of ion exchange.

The hydrophilic functionalised polyHIPE polymers may be used in bioremediation (eg of soil) to immobilise toxic cations or anions (eg- present in water from soil). Viewed from a further aspect the present invention provides a rotating disk reactor apparatus composed at least partly of a functionalised polyHIPE polymer as hereinbefore defined.

One or more surfaces of the rotating disk reactor (such as one or more of the rotating disks, preferably one or more of the porous rotating disks) may be furnished with the functionalised (eg sulphonated) polyHIPE polymer. For example surfaces of the rotor and/or stator cavities of the disks may be furnished with a hydrophilic functionalised (eg sulphonated) polyHIPE polymer. One or more of the disks may be composed wholly of a hydrophilic functionalised (eg sulphonated) polyHIPE polymer. Preferably a first disk (eg the rotor) is composed wholly of a hydrophilic functionalised (eg sulphonated) polyHIPE polymer and a second disk (eg the stator) is composed at least partly of a hydrophobic material (eg a silane coupling agent).

Viewed from a further aspect the present invention provides use of a non-uniformly functionalised polyHIPE polymer having either a hydrophilic (eg sulphonated) core and a hydrophobic skin or a hydrophobic core and a hydrophilic (eg sulphonated) skin as a water absorber or as a growth medium (eg a controlled release growth medium).

By way of example, a non-uniformly sulphonated polyHIPE polymer is_^ obtainable by injecting sheets (eg flat sheets^') of polyHIPE polymer with concentrated sulphuric acid (eg using a syringe at suitable intervals forming a pattern). This gives a hydrophilic core/hydrophobic skin.

Alternatively by way of example, a hydrophilic skin/hydrophobic core is obtainable by preparing a first (eg nitric acid or phosphoric acid) containing polyHIPE polymer under non-functionalisation conditions (eg under non-nitrating and non-phosphating conditions) and converting the first acid into an in situ salt. The polymer is soaked in a second acid (eg concentrated sulphuric acid) and functionalised (eg by raising the temperature to the sulphonation temperature) leading to skin functionalisation.

The salt may be prepared in situ by adding to the polymer a metal containing species (eg an alkali metal or an alkaline earth metal containing species). Preferred is a potassium, sodium or magnesium containing species (eg an alkali such as sodium, potassium or magnesium hydroxide). The conversion to a salt may be in general achieved in a manner familiar to those skilled in the art with conventional reagents.

Such skin/core structures derive strength from the core. Its hydrophobic nature can be exploited for slow release of salts and its hydrophilic nature for absorbency (for example in absorbing urine in nappies).

Preferred embodiments of the present invention will now be described, by way of example only, and not in any limitative sense, with reference to the accompanying drawings in which: -

Figure 1 is a schematic representation of a method of the prior art;

Figure 2 is a schematic representation of a first process embodying the present invention;

Figure 3 is a schematic sectional representation of a first apparatus embodying the present invention;

Figure 4 is plan view of a rotor of the apparatus of Figure 3;

Figure 5 is plan view of a stator of the apparatus of Figure 3;

Figure 6 is a photograph of the rotor of the apparatus of Figure 4;

Figure 7 is a photograph of the stator of the apparatus of Figure 5;

Figure 8 is a photograph of a portion of the rotor of the apparatus of Figure 4;

Figure 9 is a photograph of another portion of the rotor of the apparatus in Figure 4;

Figure 10 is a schematic sectional view of a device of a second apparatus embodying the present invention; Figures 11a and l ib show a polymer (85% void) prepared from a dispersed phase containing 5% (a) and 15% (b) respectively sulphuric acid, styrene and DVB in which coalescence pores are dispersed into the primary pores;

Figures 11 c and l id show (in non-enlarged and enlarged view respectively) an elastic polymer (85% void) prepared from a dispersed phase containing 5% sulphuric acid, styrene/DVB/2-ethyl hexacrylate in which coalescence pores are dispersed into the primary pores;

Figure 12 illustrates schematically a representation of a system used to remove tar and water from gas intensively using modified gas blowers or compressors; and

Figure 13 illustrates an arrangement for in situ soil re-mediation.

Referring to Figure 2, a feed 30 of flowable material, such as a mixture of polyethylene glycol and calcium carbonate, is fed into an extruder 32. The extruder 32 is driven by an extruder drive unit 34 which in turn is controlled by an extruder control unit 36. Extruder 32 introduces flowable material 30 into granulator 38 in the form of a highly viscous polymer melt with calcium carbonate particles dispersed therein. The granulator 38 is controlled by a granulator control unit 40 and produces a granular product 42.

Referring to Figures 3, 4 and 5, an apparatus for processing flowable material, in this example a granulator 38, has a first member or upper stator 44 having a first surface 46 which is provided with a plurality of first indentations 48. The granulator 38 also has a second member or rotor 50 which is rotated via guide shaft 52 by a motor (not shown). The rotor 50 has a second surface 54 having a plurality of second indentations 56 therein. First surface 46 and second surface 54 are separated thereby forming a cavity 58. In use cavity 58 receives a flowable material through a first inlet 60 which in turn receives the material from an extruder 32 (not shown in Figure 3).

Rotor 50 has a further second surface 62 having further second indentations 64 therein. A further first member or lower stator 66 having a further first surface 68 and first indentations 70 therein is also provided on the opposite side of the rotor 50 to stator 44.

The apparatus is also provided with heater elements 72 which produce a thermal field between the stators 44 and 66 and the rotor 50. Other heater elements (not shown) may also be applied. For example, rotor 50 may be provided with a heating element. Alternatively, the temperature of the rotor 50 and/or stator may be controlled by using channels through which fluids may be pumped to either heat or cool the apparatus as required. Since the rotor, stator and material moving therebetween are in contact whilst the apparatus is in use, heat resulting from friction may build up and in order to maintain the required temperature, cooling fluids may be required.

The position of rotor 50, relative to stator 44 as supported by pillars 76 on base 78, may be altered by height adjustors 74. This varies the size of the cavity 56 by altering the distance by first surface 46 and second surface 54, which in turn influences the particle size of the granules produced.

The apparatus 38 has further inlets 80 which may introduce further flowable material into cavity 58. The apparatus is also provided with gap 82 in second stator 66 and collecting tray 84. First indentations 48 and second indentations 56 are offset by half an indentation so that the first indentations 48 and the second indentations 56 never radially match each other. This is schematically shown in Figure 3 with these indentations offset relative to each other. The indentations 48 and 56 are shaped for different purposes. Elongate indentations are used to radially pump the material towards the outer edge of the rotor and the more circular indentations mix the components of the flowable material. In the lower rotor, indentations are designed in such a way that the pumping is radially inwards.

In use, extruder 32 introduces a flowable material through inlet 60 into cavity 58. The flowable material may be a single compound or a mixture of compounds which have been introduced together into extruder 32. For example, polyethylene glycol flakes, which are typically used as a binder, may be mixed with calcium carbonate powder, which is used to model an active ingredient or as a filler. A further active ingredient may also be included in this mixture. This material is fed into the extruder where it is heated and therefore melts to form a flowable material. The melting point of polyethylene glycol ranges from 56 to 66° C and therefore the material is extruded at around 70 C. The range of temperatures of crystallisation of the polyethylene glycol and calcium carbonate mixture is between 53 and 43° C during the cooling cycle. As a result, the temperature of the upper stator 44 is set at 52° C and the lower stator 66 at 45° C, thereby giving a temperature field across the apparatus.

Rotor 50 is rotated at around 30 r.p.m. The pressure of inflowing materials from the extruder causes the radial movement of the flowing material within cavity 58 and within the first and second indentations 48 and 56. Therefore the material is forced to follow a three-dimensional flow path passing from first indentations 48 and into second indentations 56. As a result of this radial and angular motion, and the arrangement of the first and second indentations, the material experiences both shear and extentional deformation thereby providing the highly efficient and effective mixing demonstrated by this apparatus. Also during this three-dimensional motion the molten material undergoes repeated heating and cooling cycles as well as cooling from its starting temperature of 70° as it moves radially outwards.

The molten material can be described as passing through four distinct zones as it travels radially. The first of these zones, the melt flow zone, is located closest to the inlet 60. In this melt flow zone the molten material is cooling towards the materials crystallisation temperature and therefore has a smooth morphology. Radially outward of the melt flow zone is the nucleation. In the nucleation zone the appearance of the material is similar to that in the melt flow zone. However, on closer inspection, the morphology differs in that granulation is beginning to occur. This results from the gradual cooling of the material which allows nucleation of the granule particles to start.

The crumbling zone is located radially outward of the nucleation zone. In this zone granules can clearly be seen forming. Radially beyond the crumbling zone is the granule transport zone in which granules, now formed, are transported to the edge of rotor 50. The nucleation, crumbling and granule zones can be seen in Figure 8. In Figure 9, the distinction between the shear region (towards the top of the photograph) and the mixing region (towards the bottom of the photograph) can be seen. In the mixing region (within the indentations) the granule formation can be seen and in the shear region, adjacent the edge of the indentation, the shear deformation of the material can be seen. The size of the granules is predominantly determined by the distance between the first surface 46 and the second surface 54. The distance between these surfaces is adjusted by rotation of height adjuster 74. Once granules are formed they are transported through the granule transport zone to the outside of rotor 50 where they fall on to the lower stator 66. The granules are then transported radially inwardly by the pumping action occurring between the indentations 64 and 70 and then fall down gap 82 and are collected in collecting tray 84.

Second inlet 80 may be used to add a further material which is typically used to coat the granules as they are formed. This coating is typically a powder, for example titanium dioxide, and is added to the material immediately after phase inversion during the granulation. Thus the coating material is added in the crumbling zone.

The method and apparatus of this invention are described in the publications by the inventor in Ind. Eng. Chem. Res. 2002, 41, 5436-5446, J. Materials Sci. (publication due in 2003) and The Chemical Engineer and the International Journal of Transport Phenomena (both publications due in 2004) and the contents of these publications are included in this description in their entirety by reference.

It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only, and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims. For example, it is possible to aerate the mixture in the extruder with air or another gas. This produces granules with a porous structure which will allow them to be more easily dissolved and dispersed in a solvent.

The apparatus may also be used to dry a flowable material containing a solvent. In particular the drying of a granular material mixed with a solvent may be dried in an apparatus of this type containing either a porous rotor or stator. The mixture is introduced into the apparatus and heated thereby vapourising the solvent which is drawn away from the material through the porous rotor or stator. The movement of the material between the indentations of the rotor and stator maintains movement between the granules thus preventing them clumping together. The movement also continually exposes new surface area on the granules to enhance mass transfer of the solvent. Due to the small volume of the cavity between the first and second surfaces a vacuum can be formed with relative ease. Alternatively, solvent free hot gas may be pumped into the cavity through the rotor or stator and extracted with vapourised solvent through the other.

The apparatus may also be used as a reactor in which the reactants can be introduced through the available feed points on the upper stator. The rate of reaction and degree of conversion are affected by the provision of thermal, electrical, ultrasonic, flow fields (for mixing) as well as catalysts. Continuous removal of gaseous product from the reaction media is also important. The equipment described here are able to provide these additional provisions to enhance the reaction rate. The ability of the apparatus to mix and pump and provide a large surface area for heat transfer is particularly suitable for viscous reactions which can also involve solid particles. The surface of the rotor and stator can be coated with a desired catalyst if desired.

Referring to Figure 10, an apparatus 82 for processing a flowable material, in particular for separating an emulsion has a first member 84 having a first surface 86 with a plurality of first indentations 88 therein. The apparatus also has a second member 90, which is rotatable relative to first member 84 and has a respective second surface 92. First surface 86 and second surface 92 face each other and are separated so as to define a cavity 94. Second member 90 is formed from a porous material, typically a micro-porous polymer. The size of the intemconnecting holes between the pores of the porous material, which limits the porousity of the material, are typically in the range of 0.5 micrometers to 50 micrometers. Second member 90 is rotated by driven axle 96.

The apparatus also has an inlet 98 and a first outlet 100 which in use exhausts oil and a second outlet 102 which in use exhausts water. A third outlet 104 exhausts undemulsified material. First member 84 is typically a porous hydrophobic material such as a micro-porous polymer or a sintered steel member having a pore size of 5 - 10 micrometers or a suitably porous ceramic. The porous material is made hydrophobic by coating with, for example, a saline coupling agent or an epoxide coating.

The second member 90 may be provided with second indentations 106 and is typically a hydrophilic material such as a sulphonated micro-porous polymer, or sintered metal.

In use, an emulsion is introduced through inlet 98. The second member 90 is rotated and water is attracted towards the hydrophilic second member. At the same time, oil turns towards the hydrophobic first member. Demulsified water can then be withdrawn through outlet 102 leaving demulsified oil to be withdrawn through outlet 100.

The sulphonated micro-porous polymer, described in WO 02/10070 may be added prior to the introduction of the emulsion into inlet 98. First member 84 may be coated so as to be non-porous and an electrically isolated electrode enclosed within the first member. The second member may then act as a further electrode and a voltage applied between the two. Such a voltage assists in the separation of the water from the emulsion. Because the first member 84 and the second member 90 are located close ^' to one another, the voltage to be applied across these electrodes may be significantly less than where electrodes are used to assist separation of emulsions in the prior art. Since the first electrode is insulated from the emulsion, no current flows between the electrodes and therefore the power consumption of this device is sufficiently small as to remain economical. Where the first member 84 is non-porous, outlet 100 would not be present and therefore outlet 104 will contain an increased concentration of the oil which in-part can be recycled into the apparatus 82 via first inlet 98. This enrichment of the emulsion is achieved by extraction of water through outlet 102. The use of the demulsifier polymer described in WO 02/10070 in the presence of the electric field further enhances the oil-water separation.

It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only, and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims.

EXAMPLE 1: Preparation of a Conventional Microporous Disk Reactor

Conventional microporous polymers with well controlled internal architecture (including size and distribution of pores and interconnects) were prepared through a high internal phase emulsion polymerization route as described in WO-A-00/34454. More particularly, the polymers were obtained after the polymerisation and crosslinking of a high internal phase emulsion.

Firstly a continuous phase (45 ml) containing 15 wt % Span 80, 70wt% styrene monomer and 15 wt% divinyl benzene was placed at the bottom of a mixing vessel whose internal diameter was 12cm. 255 cm of aqueous solution containing the desired amount of solute or water dispersible inclusions and 0.5% potassium persulphate (the dispersed phase) was dosed into the continuous phase while mixing for lOmins.The phase volume of the dispersed phase was 85%.

Mixing was conducted using 3 flat paddles (diameter 9 cm) stacked at right-angles to each other and the bottom impeller was as close to the bottom of the vessel as possible. The rotational speed of the impellers was 300rpm. Additional mixing time was 20 minutes. .

After preparation of the emulsion, it was transferred to a plastic mould of 12 cm diameter and 2 cm thickness and polymerised at 60°C for 8 hours to complete polymerisation. Afterwards, the mould was opened and the polymerised material was removed. However it is also possible to use a perforated mould which is sealed at the time of polymerisation to prevent emulsion escaping. In this case, the mould can act as a permanent holder^' for a porous disk. An alternative method is to use^' large containers during polymerisation and subsequently cut the porous polymer into a desired shape and size and (if necessary) place it in a holding container.

EXAMPLE 2: Preparation of a Sulphonated (hydrophilic) Disk Reactor Preparation of a sulphonated disk reactor was carried out in largely the manner described in Example 1 but in a series of experiments in which the dispersed phase contained sulphuric acid in an amount of 5, 10, 15, 20 and 25wt% respectively and the continuous phase was as described in Example 1.

The dispersed phase was dosed into the continuous phase as described in Example 1. Mixing was conducted using 3 flat paddles (diameter 9 cm) stacked at right-angles to each other and the bottom impeller was as close to the bottom of the vessel as possible. The rotational speed of the impellers was 300 rpm. Dosing of the dispersed phase was 10 minutes and the additional mixing time was varied to obtain polymer with given pore sizes.

After preparation of the emulsion, it was transfeired to a plastic mould of 12 cm diameter and 2 cm thickness and polymerised at 60°C for 6 hours to complete polymerisation. Afterwards, the mold was opened and the polymerised material was removed.

After polymerization, the temperature of the polymer was raised to 150°C to concentrate the acid in the aqueous phase. This resulted in sulphonation with the degree of sulphonation being dependent on the sulphonation temperature and time. Sulphonation for two hours resulted in the production of hydrophilic polymer which was then washed in water and^'isopropanol to remove excess acid, residual monomer.^' and the surfactant (Span 80). If sulphonation was carried out at or below 140°C, the resulting polymer did not adsorb water after washing. The dimensional stability of the sulphonated material was improved by using 25% DVB and 60% styrene.

Small samples of the polymer before and after sulphonation were cut off and were examined under a scanning electron microscope (SEM) in order to evaluate the pore size and pore structure. The results are shown in Figures 11a and l ib for sulphuric acid at levels of 5% and 15%.

An analogous reaction was conducted to prepare an elastic polymer in which the continuous phase contained an additional monomer, namely 2-ethyl hexacrylate and the dispersed phase contained sulphuric acid at 5%. The results are shown in Figures l ie and l id.

Example 3: Preparation of a Nitrated (hydrophilic) Disk Reactor

Experiments conducted by using nitric acid yielded similar results except that the maximum nitric acid concentration which could be employed was 15wt% (beyond which the emulsion broke down).

Nitration is also possible when sulphuric acid containing polymers are heated to 100°C to concentrate the sulphuric acid but not to effect sulphonation and are then contacted with concentrated nitric acid. Nitric acid addition is carried out at low temperatures near 0°C and the temperature is increased to 25°C to allow nitration.

Example 4: Preparation of a Phosphated (hydrophilic) Disk Reactor

Phosphoric acid yielded similar results except that the maximum phosphoric acid concentration which may be employed is 25wt% (beyond which the emulsion broke down).

Example 5: Preparation of in situ Salts

The polyHIPE polymers of the previous Examples when prepared with excess acid can be neutralized using a suitable alkali such as potassium or magnesium hydroxide to form an in situ salt which may be exploited as a slow release fertilizer for use in agriculture, horticulture or hydroponics. These salts are highly soluble in water and therefore slow release of such salts is less than straightforward. In general, a hydrophobic barrier may be provided to ensure slow release.

If a higher release rate is desired, a more hydrophilic polymer can be obtained using (for example) a styrene 2-ethyl hexj acrylate co-monomer. Alternatively phosphoric acid or nitric acid containing polyHIPE polymers are neutralized and then soaked in concentrated sulphuric acid for the polyHIPE polymer to adsorb some sulphuric acid Avhich can then be sulphonated by raising the temperature to 150°C or more. The excess acid can then be neutralized using a suitable alkali such as potassium or magnesium hydroxide. This will create a non-uniformly sulphonated polymer with a hydrophilic shell and a hydrophobic core with salt contained in the pores for release through diffusion. We have noted that in these preparations, the surfactant does not need to be taken out from the microporous polymer and therefore provides wetting of the walls of the hydrophobic core where most of the salt is stored. The release of salts can be controlled through the size of the pores or the size of the interconnects.

Example 6: Growth Medium

Preliminary results indicate that when 0.5% by weight of soil of a demulsifier/absorber of the present invention is used as a growth medium for lentil, it grows some 40%o faster than when no growth medium is used (eg a control experiment carried out with soil only). When conventional vermiculate is used as the growth medium, growth is 25% faster than when the control is used. These results are obtained after 12 days of seed plantation.

Example 7: Intensified Separation of Gas-Liquid Mixtures

Biomass gasification is very important in sustainable energy and power generation. However, depending on the biomass feedstock used during gasification, large amounts of tar may be present in the produced gas stream which need to be removed for the gas to be exploited in power production. The gas stream mainly consists of carbon monoxide, hydrogen, methane, nitrogen and carbon dioxide.

When such a gas stream is passed through a packed bed (or monolithic block) of a sulphonated polyHIPE polymer of the invention, separation of the tar from the gas stream takes place. The packed bed also removes moisture and particulate matter such as ash particles. The gas/liquid separation by the sulphonated micro-porous polymer of the invention is not totally due to the absorption of tar and moisture but instead appears to be due to the foimation of a pool beneath the packed bed. In order to facilitate the separation process, relatively large pore size polymers (pore size 50 to 100 microns) are used. Styrene only microporous polymers become elastic after sulphonation using sulphuric acid provided that the pore size is 40μm or more. Thus once the polymer is saturated with tar and water it may be recovered, pressed to remove the internal content and subsequently reused.

In order to remove any remaining long chain hydrocarbons within the gas stream, hydrophobic microporous polyHIPE polymers (such as those based on polystyrene - see for example WO-A-00/34454) may be used. In this case, removal of the long chain hydrocarbons will be due to capillary condensation. Once the hydrophobic microporous elastic polymer is saturated, it can be recovered and its internal content can be removed by pressing. Furthermore, the hydrocarbon filled materials can be utilised in extraction processes in which highly hydrophobic materials are preferentially absorbed onto the hydrocarbon loaded micro-porous polymer and subsequently recovered from the aqueous phase and the extracted material can be recovered in a second process.

When these polymers are used in the environmental management of the bio-waste gasification processes to remove tar, the final unusable micro-porous polymer can be burnt in the gasifier to recover its energy and non-combustible internal phase.

Example 8: Intensified Separation of Gas-Liquid Mixtures

Two types of sulphonated polyHIPE Polymer were prepared in accordance with the invention in order to test their ability to separate gas/liquid mixtures produced during the gasification of biomass or fossil fuel waste or a combination thereof.

Example 7 shows that sulphonated polymers can be used to remove tar and water from gas streams. The process can be further intensified and made practical by ^■ incorporating these polymers within gas blowers and compressors.

In gas blowers and compressors, inlet gas (containing moisture and tar) I is propelled axially and radially to create a centrifugal flow field. In such a flow field, heavier components of the gas mixture (water, mist and tar) will be more affected by centrifugal force and there will be more of these material hitting the walls of the compressor/blower than the gas molecules such as carbon monoxide, hydrogen, methane etc. Furtheimore, there are also small micron sized particles in the gas which can not be easily removed by hydrocyclones and these particles will also tend to migrate to the wall.

It is possible to capture these particles at the wall using microporous polymers such as those referred to above for gas/tar/water separation. A schematic representation of the system is shown in Figure 12. The polymers 102 can be packed round the walls of the blowers/compressors although they need to be protected by a perforated metallic shield in the form of a cage 103. The other side of the cage forms a closed chamber where the differential pressure is monitored and has an outlet for gas 105 and highly viscous tar 104. When the tar and particulate matter accumulates within the pores of the polymer, a highly strong barrier is formed against the penetration of gases thus forming a self-sealing system. A small pressure differential is applied between the blower/compressor chamber and the other side of the porous structure to ensure the integrity of the porous membrane/tar system as well as to allow the tar/water (and some gas) to flow across the porous barrier. As these components appear at the other side of the banier, they can be pumped out slowly so as to maintain the barrier integrity.

The use of sulphonated microporous polymers in this separation process enhances the adsorption of tar and water and ensures the integrity of the porous barrier since^' the polymers have an affinity for tar and water. When the polymer collector is saturated, it can be removed and replaced. However, this method cannot be applied at high temperatures. For high temperature applications, metallic microporous polyHIPE polymer structures are better. Such structures should also be in modular form (cartridge) to allow replacement when too much particulate matter accumulates. Such microporous modular forms of microporous polyHIPE polymer structures (with interconnect size ranging from 1-10 microns) can be removed and burned or acid treated in order to be used again.

Example 9: Skin/Core Structures In order to obtain skin/core polymers, styrene polyHIPE polymers prepared as in WO- A-00/34454 can be moulded into sheets (3 cm thick) and concentrated sulphuric acid then applied from both sides. No excess free acid is needed. The temperature is then raised to 60C or more (up to 170C maximum) and the polymer is allowed to sulphonate and subsequently neutralized and washed in the usual way. The sheets are the cut up into two 1.5 cm thick and any desired shape.

This example reveals a hydrophobic core which can be seeded with bacteria for use in agriculture, horticulture, hydroponics or biotechnology. If the hydrophobic core does not need to be exposed, suitably cut pieces of polyHIPE polymer (for example 1 cm sized cubes) can be soaked in concentrated sulphuric acid and the temperature raised above 60C (up to 170C in order to increase the rate of sulphonation) to complete sulphonation followed by neutralization and washing.

It is also possible to obtain hydrophilic (sulphonated) core and hydrophobic skin. In this case, flat sheets of polyHIPE polymer are injected with concentrated sulphuric acid using a syringe at suitable intervals forming a pattern. These sheets are then cut up and sulphonated followed by washing.

Example 10: Application of Microporous Polymers to in situ Soil Re-mediation

Electroosmosis may be used to transport toxins and metal cations to a porous cathode 111 as shown in Figure 13. A porous anode 112 and the cathode 111 in Figure 13 are made of porous carbon. This porous cathode 111 is surrounded by a cation exchanger sulphonated microporous co-polymer 113a, 113b which acts as a metal ion adsorption barrier. Any remaining metal ions are deposited on the electrode 111.

The organic toxins then pass through a non-ionic barrier 114a, 114b, to a bio-reactor 115 which contains either encapsulated enzyme or bacteria supported by microporous polymers. Water from the bioreactor is then recirculated back to the anode 2 as illustrated in Figure 13. Both the anode 112 and the cathode 111 and its supporting compartments (cation exchanger 113a, 113b, non-ionic barrier 114a, 114b and the bioreactor 115) can be inserted into the soil and periodically removed when each component functions efficiently. It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only, and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims.

Claims

1. An apparatus for processing flowable material, the apparatus comprising:

at least one second member rotatable relative to at least one respective first member and having a respective second surface provided with a plurality of second indentations, wherein at least one second surface faces a corresponding first surface to define a respective cavity for receiving flowable material; and

at least one first inlet for introducing at least one first flowable material into at least one said cavity.

2. An apparatus according to claim 1, further comprising insertion means for introducing at least one said first flowable material into at least one said cavity under pressure.

3. An apparatus according to claim 2, wherein said insertion means comprises at least one extruder.

4. An apparatus according to any one of the preceding claims, further comprising field induction means for inducing a field between at least one said first member and at least one said second member.

5. An apparatus according to claim 4, wherein said field induction means induces a thermal field.

6. An apparatus according to claim 5, wherein at least a portion of the or each said first member is at a temperature below the melting point of at least one said first flowable material and at least a portion of the or each said second member is at a temperature below the temperature of said portion of said first member.

7. An apparatus according to any one of claims 4 to 6, wherein said field induction means induces an electrical field.

8. An apparatus according to any one of claims 4 to 7, wherein said field induction means induces an ultrasonic field.

9. An apparatus according to any one of claims 4 to 8, wherein said field induction means induces a field which differs radially along said first member and/or said second member.

10. An apparatus according to any one of the preceding claims, wherein said first member and/or said second member is hydrophilic.

1 1. An apparatus according to any one of the preceding claims, wherein said first member and/or said second member is hydrophobic.

12. An apparatus according to any one of the preceding claims, wherein a plurality of said indentations in at least one said first surface are out of phase with a plurality of said indentations in the corresponding second surface in directions radial to said axis of rotation.

13. An apparatus^' according to any one of the preceding claims, wherein at least one said first or second surface is substantially circular in a direction transverse to an axis of rotation.

14. An apparatus according to any one of the preceding claims, wherein at least one said first member is provided with a plurality of said first surfaces.

15. ^• An apparatus according to any one of the preceding -claims, wherein at least one said first inlet is arranged adjacent an axis of rotation of at least one said second member relative to the corresponding said first member.

16. An apparatus according to any one of the preceding claims, further comprising at least one second inlet is arranged radially outwards from a said first inlet.

17. An apparatus according to claim 16 wherein at least one said second inlet introduces at least one second flowable material into at least one said cavity.

18. An apparatus according to any one of the preceding claims, wherein the separation between at least one said second member and the coiresponding said first member is adjustable.

19. An apparatus according to any one of the preceding claims, wherein at least one of said first or second surface comprises at least one porous surface.

20. An apparatus according to claim 19, wherein at least one said porous surface comprises at least one micro-porous surface.

21. An apparatus according to claim 20, wherein at least one micro-porous surface comprises at least one micro-porous polymer.

22. An apparatus according to claim 21, wherein at least one said micro-porous polymer comprises at least one sulphonated micro-porous polymer.

23. An apparatus according to any one of the preceding claims, wherein at least one said first or second surface is metallic which can be coated with a catalyst.

24. An apparatus for processing flowable material, the apparatus substantially as hereinbefore described with reference to Figures 2 to 8 of the accompanying drawings.

25. An apparatus for processing flowable material, the apparatus comprising:

at least one second member rotatable relative to at least one respective first member and having a respective second surface comprising at least one porous surface, wherein at least one second surface faces a coiresponding first surface to define a respective cavity for receiving flowable material and said porous surface allows a first component of said flowable material to be separated from a second component of said flowable material; and

26. An apparatus according to claim 25, wherein at least one said porous surface comprises at least one micro-porous surface.

27. An apparatus according to claim 26, wherein at least one micro-porous surface comprises at least one micro-porous polymer.

28. An apparatus according to any one of claim 25 to 27, wherein said second surface provided with a plurality of second indentations.

29. An apparatus according to any one of claims 25 or 28, further comprising insertion means for introducing flowable material into at least one said cavity under pressure.

30. An apparatus according to any one of claims 25 to 28, further comprising field induction means for inducing a field between at least one said first member and at least one said second member.

31. An apparatus according to claim 30, wherein said field induction means induces a thermal field.

32. An apparatus according to claims 30 or 31, wherein said field induction means induces an electrical field.

33. An apparatus according to any one of claims 30 to 32, wherein said field induction means induces a ultrasonic field.

34. An apparatus according to any one of claims 30 to 33, wherein said field induction means induces a field which differs radially along said first member and/or said second member.

35. An apparatus according to any one of claims 25 to 34, wherein said first member and/or said second member is hydrophilic.

36. An apparatus according to any one of claims 25 to 35, wherein said first member and/or said second member is hydrophobic.

37. An apparatus according to any one of claims 26 to 36, wherein said indentations in the or each said first surface are out of phase with said indentations the respective second surface.

3^'8. An apparatus according to any one of claims 25 to 37, wherein at least one said first or second surface is substantially circular in a direction transverse to an axis of rotation.

39. An apparatus according to any one of claims 25 to 38, wherein at least one said first member is provided with a plurality of said first surfaces.

40. An apparatus according to any one of claims 25 to 39, wherein at least one said first inlet is arranged adjacent an axis of rotation of at least one said second member relative to the corresponding said first member.

41. An apparatus according to any one of claims 25 to 40, wherein the separation between at least one said second member and the coπ-esponding said first member is adjustable.

42. An apparatus according to an)' one of claims 25 to 41, wherein at least one said first or second surface is metallic.

43. An apparatus for processing flowable material, the apparatus substantially as hereinbefore described with reference to Figure 9 of the accompanying drawings.

44. A method of processing flowable material, the method comprising the steps of:-

45. A method according to claim 44, wherein said process is granulation.

46. A method according to claim 44, wherein said process is mixing.

47. A method according to claim 44, wherein said process is drying.

48. A method according to claim 44, wherein said process is chemical reaction.

49. A method of processing flowable material, the method comprising the steps oft-

introducing a first flowable mixture of materials into at least one cavity defined between a first surface of a first member, and a second surface of a second member, the first surfaces having indentations therein adapted to receive said flowable mixture of materials and the second surface comprising at least one micro-porous polymer; and

rotating at least one said second member relative to the corresponding first member so as to process said material.

50. A method according to claim 49, wherein said process is separation.

51. A process for preparing a functionalised polyHIPE polymer comprising:

(b) obtaining in a second phase a functionalising agent;

52. Substantially uniformly functionalised polyHIPE polymer or a salt thereof in bulk.

53. A method for isolating a liquid from a gas in a liquid-gas mixture, said method comprising: contacting the liquid-gas mixture with a functionalised polyHIPE polymer obtainable by a process as defined in claim 51.

54. Use of a functionalised polyHIPE polymer obtainable by a process as defined in claim 51 as a demulsifier.

55. A blower or compressor wherein at least one wall is at least partly composed of or coated with a functionalised polyHIPE polymer obtainable by a process as defined in claim 51.

56. Use of a hydrophilic functionalised polyHIPE polymer obtainable by a process as defined in claim 51 as a water absorber.

57. Use of a hydrophilic functionalised polyHIPE polymer obtainable by a process as defined in claim 51 as a growth medium.

58. Use of a hydrophilic functionalised polyHIPE polymer obtainable by a process as defined in claim 51 as an ion exchange medium or in bioremediation.

59. A rotating disk reactor apparatus composed at least partly of a functionalised polyHIPE polymer obtainable by a process as defined in claim 51.

60. Use of a non-uniformly sulphonated polyHIPE polymer having either a hydrophilic core and a hydrophobic skin or a hydrophobic core and a hydrophilic skin as a water absorber or as a growth medium.