WO2008099131A1

WO2008099131A1 - A biomass extraction apparatus

Info

Publication number: WO2008099131A1
Application number: PCT/GB2007/004609
Authority: WO
Inventors: Mark Andrew Cleaver
Original assignee: Ineos Fluor R, T & E
Priority date: 2007-02-14
Filing date: 2007-11-30
Publication date: 2008-08-21
Also published as: GB0702783D0; GB2446596A

Abstract

A biomass extraction apparatus (10) comprises a hollow, fluid-proof receptacle (11) haying a hollow neck (12) defining an opening (13) and including one or more neck formations (14); a filter (17); an aerosol valve (18); and a collar assembly (19) defining a hollow chamber and having one or more retention formations (19c) that are engageable with one or more said neck formations (11) to permit securing of the collar assembly (19) relative to the neck (12) and thereby locate the filter (17) to permit filtering of fluid passing via the neck (12). The collar assembly locates the aerosol valve (18) with its actuator (18b) accessible via the hollow chamber, the apparatus including an actuator assembly (22) that is operable from outside the chamber to act on the aerosol valve (18) in the hollow chamber and thereby adjust the degree of opening of the aerosol valve (18). The collar assembly (19) optionally includes one or more collar formations (19f) defined in the hollow chamber; and a position-adjustable securing member (23) including one or more securing formations (23e) that are engageable with the collar formations (19f) to permit securing of the filter (17) and the aerosol valve (18) relative to the collar assembly (19).

Description

A BIQMASS EXTRACTION APPARATUS

This invention relates to a biomass extraction apparatus.

The topic of biomass extraction has grown in scientific and economic importance in recent years. Biomass extraction involves treating biomass (i.e. biological matter) so as to extract from it fractions or sub-components of interest. In biomass extraction processes the biomass may or may not be pre-treated. (e.g. by dividing it finely, moistening it with water or otherwise preparing it for extraction) to enhance the extraction regime.

Typically biomass extraction involves the use of solvents to remove only selected sub-components while leaving a residue of biomass that is of lesser commercial interest. Alternatively, the biomass may be treated in order selectively to extract an undesirable component in order to leave a treated biomass having greater commercial interest. One highly successful technique for extracting components from the biomass involves the use of R-134a (which is well-known as a volatile fluid developed for use in air conditioning apparatuses) or a similar compound as the solvent. R-134a in particular offers significant advantages in terms of the selectivity of the components that are extracted using it.

Biomass extraction may have as its aim the extraction of e.g pharmaceutically active compounds from plant matter. Another, at the present time commercially significant, aim of biomass extraction is to obtain concentrated flavours and fragrances that are used either to add aromas to foods, drinks and scented products, or to add flavours to foods and drinks that are produced on a commercial scale.

Very commonly consumers of such products find the flavours and aromas that mimic natural materials highly appealing when used to scent and/or flavour the products. The production of flavours and fragrances based on biomass extracts typically takes place in production plant in industrialised locations. This is not least because there is a requirement for production-scale plant in the flavours and fragrances industry to have access to high-output electrical power supplies.

Often however there are significant marketing benefits to the incorporation, in consumer goods, of flavours and fragrances that are rare, are considered exotic or are associated with natural healing effects.

The biomass types from which such flavours and fragrances are derived typically exist in inhospitable locations such as jungles, rainforests and in remote places in which the use of powered extraction equipment is extremely prohibitive. Obtaining pharmaceutically active compounds from biomass also often involves travel to remote locations. Further, the particular plant materials may only be available in very small quantities in such locations.

Within the flavours and fragrances industries certain workers have the task of visiting such places hi order to locate new sources of known biomass; and to identify new types of biomass that may prove commercially useful.

It is strongly desirable for such workers to be able to assess both the viability of biomass extraction using these various new sources of biomass and, more importantly, the available qualities of the extracts. It is not however practical for such workers, whose accommodation at such times might amount to no more than a vehicle and camping equipment, to operate a powered biomass extraction apparatus in order to complete these assessments.

It has consequently become known to provide, for the purpose of completing "field" tests on biomass, a portable biomass extraction apparatus. This operates on the basis of energy stored in and the volatility of a solvent fluid such as R- 134a. In the known apparatus a glass flask is joined via a manually operated, two- position valve selectively to connect the interior of the flask (via fluid-tight pipes) to a source of R-134a under pressure, or to a discharge tube for extracted biomass.

The method of operation of this apparatus involves firstly placing a quantity of biomass in the flask, and then connecting the various pipes to the flask so as to seal the biomass therein. The valve is then opened to connect the interior of the flask to a pressurised source of R- 134a or a similar solvent so that the solvent flows into the interior of the flask and percolates through the biomass. The valve is then closed to seal the solvent in the flask with the biomass.

Over a period the biomass then extracts the target components from the biomass. The length of this period typically is judged according to the nature and quantity of the biomass.

Once the extraction is completed the valve is further adjusted to connect the interior of the flask to the discharge tube. Tilting of the flask may then permit the extract and solvent to be poured from the interior via the discharge pipe. The extract is run off, as a liquor, into a separate vessel for assessment and/or subsequent transportation. The solvent is sufficiently volatile that the pressure drop it experiences on being poured from the flask causes flash evaporation whereby the extract and the solvent are separated from one another before the former is poured into the separate vessel.

Although in principle such an apparatus is capable of providing biomass extraction, without the need for external power sources, in a field environment in practice it suffers from numerous disadvantages.

One is that the equipment from which the apparatus is assembled is virtually all custom-made. Aside from the expense associated with manufacture of such equipment, in a field situation it is necessary to carry several spare examples of each part of the apparatus in order to cater for loss and damage (which commonly occur). Furthermore the apparatus is comparatively heavy to carry. Also no part of it is capable of easily being recycled in the field yet very commonly it is necessary to re-use e.g. the flask. This is usually only possible after first thoroughly cleaning it (so that a subsequent extraction campaign is not tainted by the residue of an earlier one).

The cost of especially the valve used in the known apparatus is, furthermore, unattractive. Other proposals, armed at employing cheaper valves, have proved impractical.

An aim of the invention is to solve or at least ameliorate one or more of the disadvantages of the prior art.

In accordance with the invention there is provided a biomass extraction apparatus comprising a hollow, fluid-proof receptacle having a hollow neck defining an opening and including one or more neck formations; a filter; an aerosol valve; and a collar assembly defining a hollow chamber and having one or more retention formations that are engageable with one or more said neck formations to permit securing of the collar assembly relative to the neck; to locate the filter to permit filtering of _.fluid passing via the neck; and to locate the aerosol valve with its actuator accessible via the hollow chamber, the apparatus including an actuator assembly that is operable from outside the chamber to act on the aerosol valve in the hollow chamber and thereby adjust the degree of opening of the aerosol valve.

An advantage of the apparatus of the invention is that the components making it up may be provided as cheap, readily available parts. In particular the aerosol valve may be provided as a low cost item, manufacturing-tolerances in which may be accommodated on assembly of the apparatus by virtue of the nature of the other components mentioned. Furthermore the use of a collar assembly as defined means that the apparatus may accommodate manufacturing tolerances in e.g. the receptacle. The parts additionally may be made as lightweight ones that therefore are easy to convey even in remote locations. Preferably the collar assembly includes one or more collar formations defined in the hollow chamber; and a position-adjustable securing member including one or more securing formations that are engageable with the collar formations to permit securing of the filter and the aerosol valve relative to the collar assembly.

In practice therefore the collar assembly may function as a clamp for clamping the filter and the aerosol valve to the receptacle. The apparatus of the invention therefore need not be pre-assembled and instead may be carried as a set of discrete parts until needed for use. This further assists use of the apparatus in field conditions.

Conveniently the securing member in use protrudes partly from the hollow chamber so as to permit adjustment of its position from outside the collar assembly. Thus on assembly of the apparatus the degree of tightening of the securing member may easily be adjusted.

In an alternative arrangement the securing member in use may optionally lie within the hollow chamber. In such a case the apparatus includes a tool that is engageable with the securing member so as to permit adjustment of the position of the securing member from outside the collar assembly. An advantage of this arrangement is that the degree of tightening of the securing member may not be inadvertently altered once it is set for use.

In a preferred embodiment of the invention the collar formations and the securing formations are or include mutually engageable screw threads formed respectively on the collar assembly and the securing member. This permits convenient adjustment of the position of the securing member, regardless of whether it lies entirely within the hollow chamber or partly protruding therefrom.

In one embodiment of the invention the actuator assembly includes a moveable member that is engageable with the aerosol valve via one or more apertures, at least a part of the moveable member protruding on the exterior of the chamber. The feature of the moveable member being engageable via an aperture confers compactness on the arrangement of the invention; and the part protruding outside the hollow chamber facilitates adjustment of the degree of opening of the aerosol valve, Preferably therefore the moveable member engages the aerosol valve via an aperture formed in the securing member.

It is also preferable that the apparatus of the invention includes a valve adapter that in use interconnects the moveable member and the aerosol valve.

This advantageously permits the moveable member to adapt to a range of types of aerosol valves. Therefore the apparatus of the invention may be assembled without great concern for the precise type of aerosol valve employed, these being mostly of similar designs such that the adapter may accommodate the majority of variants available.

Conveniently the valve adapter includes a hollow conduit permittrng flow of fluid via the aerosol valve between the interior and the exterior of the hollow chamber. Thus the adapter may be arranged so as not to hamper the inflow of solvent or the discharge of extract during use of the apparatus.

In one preferred embodiment of the invention the valve adapter includes a widened portion defining the hollow conduit that is connected to an elongate pipe that extends through the moveable member and terminates in an open end externally thereof.

Preferably the moveable member is rotatable relative to the remainder of the assembly to adjust the degree of opening of the aerosol valve, and in particular is threadedly secured to the remainder of the apparatus. The use of a rotatable adjustment facility renders the apparatus of the invention especially suitable for ensuring controlled release of the refrigerant.

Conveniently the receptacle is a bottle, and more particularly is a polyethylene terephthalate (PET) bottle of the kind normally used to contain carbonated soft : drinks. A significant advantage of employing such bottles in the apparatus of the invention is that they are availahle very widely throughout the world. Thus a field worker using the apparatus of the invention typically needs to locate only a comparatively small settlement in order cheaply to access a ready supply of the receptacles. The worker may regard such bottles virtually as disposable items in the sense that their value is low. Therefore there is no benefit in seeking to clean the PET bottles for re-use in further extraction operations after an initial use.

It follows that the neck formations of the receptacle may conveniently include one or more screw threads defined on the exterior surface of the neck of the bottle; and the retention formations may be or may include complementary screw threads formed on an interior surface of the collar assembly.

In an alternative arrangement however the neck formations may include a flange formed on the exterior of the hollow bottle adjacent the neck, and the retention formations may include one or more resiliently deformable clamping members secured to an end of the collar assembly so as to permit resiliently deformable clamping of the flange by the collar assembly.

A PET bottle usually includes formed adjacent its open neck a flange of the kind contemplated within this aspect of the invention, as well as the aforementioned screw thread. The use of resiliently deformable clamping members in order to grip the flange may be advantageous in catering for variations that may occur in the threads of the necks of different PET bottle designs.

Preferably the neck formations include an annular series of the resiliently deformable clamping members arranged about the periphery of an open end defined in the collar assembly. More particularly the or each resiliently deformable member is or includes a finger extending from the collar assembly.

Regardless of the precise receptacle-gripping arrangement adopted the actuator assembly in use conveniently defines an exterior surface having formed thereon one or more formations assisting manual gripping thereof. The invention in addition resides in apparatus as defined hereinabove when connected to a source of a pressurised solvent, especially a hydrofluorocarbon and more specifically a hydrofluoroalkane or hydrofhαoroallcene selected from the list comprising trifluoromethane (R-23), fluoromethane (R-41), difluoromethane (R- 32), pentafluoroethane (R-125), 1,1,1-trifiuoroethane (R-143a), 1,1,2,2- tetrafiuoroethane (R-134), 1,1,1,2-tetrafiuoroethane (R- 134a), 1,1-difluoroethane (R- 152a), heptafluoropropanes and particularly 1, 1,1,2,3, 3,3-heptafhioropropane (R-227ea), 1,1,1,2,3,3-hexafiuoropropane (R-236ea), 1,1,1,2,2,3- hexafluoropropane (R-236cb), 1,1,1,3,3,3-hexafluoropropane (R-236fa)₅ 1,1,1,3,3- pentafluoropropane (R-245fa), 1,1, 2,2,3 -pentafluoropropane (R-245ca), 1,1,1,2,3- pentafiuoropropane (R-245eb), 1,1,2,3,3-pentafluoropropane (R-245ea), 1,1,1,3,3- pentafiuorobutane (R-365mfc) and hydrofluoropropenes including 1,2,3,3,3- pentafluoropropene (R-1225ye) and 2,3,3,3-tetrafluoropropene (R-1234). Mixtures of such solvents are possible within the scope of the invention.

R-134a is particularly preferred, partly because of its ready availability as an air conditioning gas.

LQ this regard many of the locations that are of interest from the viewpoint of biomass extraction tend to be in hot countries where pressurised canisters of R- 134a are readily available e.g. in retail garages, in even the smallest communities. Therefore a worker travelling to such a location for the purpose of conducting biomass extraction tests using the apparatus of the invention may readily have access to a source of solvent, without having to import it himself. Since the personal importation of volatile compounds via ports and airports typically is subject to regulatory restriction or prohibition this is a significant advantage of the apparatus of the invention.

There now follows a description of preferred embodiments of the invention, by way of non-limiting example, with reference being made to the accompanying drawings in which: Figure 1 is a side elevational, partly-sectioned view of a first embodiment of apparatus according to the invention;

Figure 2 shows in partly-sectioned view part of the Figure 1 apparatus including an alternative collar in accordance with a second embodiment of the invention;

Figure 3 a shows in partly-sectioned view the principal parts of a third embodiment of the invention; and

Figure 3b shows in plan and elevational view a securing member forming part of the Figure 3 a apparatus, together with a removable tool that is engageable with the securing member for the purpose of adjusting it.

In Figure 1 a portable, lightweight apparatus 10 in accordance with the invention, shown for clarity in disassembled form, comprises a hollow, fluid-proof receptacle in the form of a PET bottle 11.

As mentioned a bottle of this type is available in a range of sizes virtually throughout the world. Therefore a user of the apparatus would encounter no difficulty in accessing a ready, cheap source of them. As a consequence there is almost no need for the user to carry the bottles when travelling to and from locations where biomass tests are required.

Other types of receptacle are possible within the scope of the invention, but PET bottles as shown are preferred because of the aforesaid ease of supply. Further, PET bottles are often advantageously transparent allowing the direct observation of the biomass-solvent contact process.

As is well known, the main body of a PET bottle is essentially a hollow cylinder that is closed at one end 11a and at the opposite end lib includes a cylindrical neck 12 of lesser diameter than the main body and defining an opening 13. The neck 12 is formed with neck formations that in the embodiment shown are constituted firstly by a screw thread 14 formed on the otherwise straight-sided exterior of the neck 12; and secondly by a circular flange 16. Flange 16 is formed integrally with the remainder of the bottle 11 and is of a diameter intermediate those of the neck 12 and the main body.

The apparatus 10 includes located adjacent neck 12 a filter 17. This is in the form of a perforated, circular disc 17a having a sheet 17b of mesh material extending across its central bore such that any fluid passing via the filter flows through the mesh.

Apparatus 10 also includes an aerosol valve 18 of a kind that is commonly used in the construction of an aerosol canister. When the apparatus 10 is fully assembled the valve 18 is secured to the bottle 11, further away from the neck 12 than the filter 17.

Valve 18 includes an annular mounting flange 18a having protruding therefrom on a front side of the valve 18 an actuator in the form of a hollow button 18b; and on the opposite side of the mounting flange 18a and formed integrally therewith a depending skirt 18c. Formed integrally with and extending away from skirt 18c is a spigot 18d to which a feed pipe is usually attached when the valve 18 is used in an aerosol canister. By reason of the preferred method of operation this part 18d is not used in the same way in the apparatus 10 of the invention, but does serve to define a through-going bore 18e extending through the aerosol valve 18 from one end to the other. Bore 18e is normally closed and is progressively openable and closeable by way of the actuator button 18b, which is moveable under manual pressure into and out of mounting flange 18a.

The filter 17 and aerosol valve 18 are relatively cheap, relatively small components. Therefore they may easily be carried in the luggage of a user of the apparatus 10 in sufficient numbers to permit multiple uses of the apparatus to extract different products.

The designs of aerosol valves tend to vary from manufacturer to manufacturer, such that there will be a degree of tolerance in e.g. the choice of diameter of the flange 18a. Such variations are essentially of no consequence in the apparatus of the invention since it includes collar assembly 19 that is intended to secure the filter 17 and valve 18 adjacent the end of the neck 12, notwithstanding the minor design variations encountered.

Collar assembly 19 includes in the Figure 1 embodiment a hollow, cup-like member 19a of circular cross-section.

At one end 19b the diameter of cup-like member 19a is slightly larger than that of the exterior of neck 12. On its interior surface the end 19b of member 19a includes formed therein retention formations in the form of an internal thread 19c. Thread 19c is of complementary profile to thread 14 of neck 12, such that member 19a may be screwed by hand onto neck 12 in a fluid-tight manner.

At the end 19e opposite end 19b member 19a is of a larger diameter. To accommodate this change in diameter along its length member 19a includes, partway along its length a shoulder 19d that is evident both on the exterior and interior surfaces of the member 19a, which latter defines a hollow interior of the collar assembly.

The diameter of the enlarged part of member 19a is such that filter 17 may be received within the hollow interior of the collar assembly 19 lying- flush against the shoulder 19d.

The relative dimensions of the hollow interior and the aerosol valve 18 are such that the valve may also be received within the hollow interior. A spacer member 21 in the form of a hollow cylindrical member supports the aerosol, when so inserted, in order to prevent the spigot 18d from engaging and damaging the mesh 17b of the filter 17 and to align the aerosol valve 18 in the hollow interior so that adequate sealing of the parts together may be achieved on assembly of the apparatus. To this end the spacer 21 is of a slightly smaller diameter than the flange 18a of the aerosol valve 18, whereby in use the flange 1 Sh rests on the free end of spacer member 21 that is remote from the filter 17.

The axial length of the spacer member 21 is chosen so that the actuator button 18b in use lies within the hollow interior. Button 18b however is accessible from outside the hollow interior, by way of an actuator assembly 22 described below.

Actuator assembly 22 includes a moveable member 22a that is insertable, on assembly of the apparatus 10, into the hollow interior of collar assembly 19, in order to engage actuator button 18b. This is achieved in the Figure 1 embodiment by virtue of the presence of a valve adapter 22b that is securable to the moveable member 22a so as to interconnect the member 22a and the actuator button 18b inside the hollow interior of collar assembly 19.

Moveable member 22a is rotatably secured to the collar assembly 19 by way of a position-adjustable securing member that in the embodiment shown in Figure 1 takes the form of a further collar 23.

Further collar 23 is therefore a hollow, cylindrical member that is completely open at one end 23a that is remote from the neck 12 and filter 17 of the apparatus.

At its opposite end 23b further collar 23 includes a circular flange 23 c that partly closes end 23b, save for a central, through-going aperture 23d.

The outer diameter of flange 23 c is greater than that of the remainder of the further collar 23. The exterior surface of flange 23 c is formed as securing formations in the form of an external screw thread 23e. Screw thread 23e is engageable with a complementary thread 19f defining a collar formation defined in the hollow interior of collar assembly 19.

The exterior of further collar 23 away from flange 23 c is formed with knurls or other formations permitting manual gripping as signified by numeral 23 f in Figure 1. In use of the apparatus 10 the knurls etc 23 f protrude outside the hollow interior of collar assembly 19.

The construction of further collar 23 and collar assembly 19 are such as to permit screwing of the further collar 23 into the hollow interior of collar assembly 19 in order to trap and retain the filter 17, spacer member 21 and aerosol valve 18 in the hollow interior in the order visible in Figure 1. When these parts are so configured any fluid passing between the interior of bottle 11 and the exterior of aerosol valve 18 passes through filter 17. This is described in more detail below.

An in-use lower face of spacer 21 seals onto the top rim of filter 17. The internal diameter of disc 17a is smaller than the rim diameter of neck 12. This enables neck 12 to seal on the bottom face of disc 17a.

Aperture 23 d in flange 23 c is further formed with a screw thread 23 g on its surface.

Moveable member 22a is a generally cylindrical, hollow member that at one end 22b is of a lesser diameter than at the other end 22c. A shoulder 22d on the exterior of member 22a defines the boundary between the two portions of differing diameter.

Reduced diameter end 22b includes on its exterior surface a screw thread 22e that is of complementary profile to thread 23g of flange 23c, as a result of which it is possible to screw moveable member into aperture 23d. Knurls, grooves or similar features 23h formed on ^"the exterior of moveable member 23 a are accessible outside the hollow chamber of collar assembly 19 in order to facilitate this activity.

When moveable member is thus screwed into aperture 22d part of end 22b may, by adjusting the extent of screwing in of moveable member 23 a, be made to protrude from flange 23 c so as to engage valve adapter 22b. Valve adapter 22b is essentially disc-like as shown, so that movement of moveable member 23 a in and out (in dependence on the extent to which it is screwed into flange 23 c) drives valve adapter 22b axially relative to the remainder of apparatus 10.

Since as shown valve adapter 22b is disc-like such movement causes adapter 22b to engage actuator button 18b and, as desired, depress or release it in order to open and close the aerosol valve.

As is well known, actuator button 18b includes a central bore defining a fluid conduit 18f . Valve adapter 22b includes formed therein a through-going bore 22g that is aligned with the bore of the button 18b.

Secured on a spigot 22h protruding from valve adapter 22b is an elongate pipe 24 the hollow interior of which communicates with bore 22g mentioned above.

Pipe 24 extends through aperture 23 d in further collar 23 and thence via a central, elongate bore 22i in moveable member 22a to protrude on the exterior thereof.

The diameter of pipe 24 is such that it may readily be connected to e.g. a canister of pressurised R-134a (or another solvent, or a mix of solvents, as mentioned herein) that typically is of the type sold for the replenishment of small-scale air conditioning systems such as so-called "room coolers", or vehicle climate control apparatuses.

In a "field" situation the user of the apparatus 10 might typically carry the various parts of the apparatus, plus a canister as aforesaid, to a location where samples of a chosen biomass are available. The parts may be carried as a kit containing several examples of the parts (PET bottle 11, filter 17, aerosol valve 18, spacer member 21, valve adapter 22b and pipe 24) that would contact solvent and/or extract and hence are not re-useable without cleaning. The user would take one of each of the aforementioned parts, plus a cup-like member 19a, a moveable member 22a and a further collar 23 and would assemble

^• the apparatus 10 apart from the PET bottle 11. In doing this the user would ensure that the filter 17, spacer member 21, valve adapter 22b and aerosol valve 18 are correctly located relative to the cup-like member 19a before screwing the further collar 23 into the cup-like member firmly to secure the various internal parts in place.

The user would then attach pipe 24 to spigot 22h of adapter 22b, and pass it through bore 22i of moveable member 22a. The user would screw the latter a short distance into aperture 23d so that the moveable member 22a is retained in the apparatus, but not so far that the aerosol valve 18 is opened at all through engagement of the valve adapter 22b.

Thereafter the user would place a sample of biomass in the PET bottle 11 and screw reduced diameter end 19b of cup-like member 19a onto screw threads 14 of neck 12; and then connect pipe 24 to a solvent canister using a regulator or coupling that typically is supplied as part of the canister. The apparatus 10 is then ready to perform an extraction operation.

The next stage therefore would involve rotating the moveable member 22a to screw it further into aperture 23 d. This drives valve adapter 22b into engagement with actuator button 18b the resulting depression of which opens the aerosol valve 18.

Since the solvent in the canister is under pressure, solvent will then flow via the valve 18 and filter 17 into the interior of bottle 11 where it mingles with the biomass and commences an extraction process.

Once a desired quantity of solvent (which may be estimated e.g. "by eye" or by timing the flow of fluid from the canister) has entered the PET bottle 11 the moveable member 22a is unscrewed causing it to withdraw partially from the hollow interior of collar assembly 19 to close the aerosol valve 18 again. At this stage the canister is disconnected from pipe 24 and the apparatus 10 left for a period to give time for the extraction to occur.

At the end of this period (which is variable according to e.g. the nature and quantity of the biomass and the choice of solvent) the bottle is inverted so that the pipe 24 extends downwardly. This assures that the spigot 18d is covered with the liquid in the PET bottle 11, whereupon the moveable member 22a is once again screwed in to the hollow chamber to cause the valve adapter 22b to press on actuator button 18b and open the aerosol valve 18.

As a result the contents of the PET bottle drain via the pipe 24. During this stage any solid matter is prevented from passing into, and blocking, pipe 24 by the filter 17; and (as a result of its volatility) the solvent flashes to vapour as a result of the pressure drop occurring typically at the free end of the pipe 24. In consequence a stream of solvent rich in liquid or finely-divided solid biomass extract flows from the free end of pipe 24 and may be collected in a separate vessel in order to undergo assessment.

The apparatus of the invention therefore meets all the desirable aims of biomass extraction apparatus intended to be used in a "field" situation. In this regard it is noteworthy that both the moveable member 22a and the further collar 23 may be grasped and rotated from outside the hollow interior of collar assembly 19. This facilitates use of the apparatus in inhospitable environments and provides a degree of fine control of expulsion of the extract-rich solution.

Figure 2 shows a variant on the Figure 1 apparatus.

The Figure 2 equipment differs from that shown in Figure 1 only in relation to the manner of connection of the collar assembly 19 to the PET bottle 11, all other parts of the apparatus being ϋie same as between the two embodiments. In Figure 2 cup-like member 19a is replaced by a straight-sided cylinder the end 19b of which that lies remote from screw thread 19f omits either a reduced diameter portion or the screw thread 19c. Instead the end 19b is formed as an annular series of equi-spaced, equal length, resiliently deformable fingers 26.

The fingers may include formed on their inner sides (not visible in Figure 2) embossments but regardless of their precise design the fingers serve resiliently to grip over the flange 16 of PET bottle 11, as an alternative to employing the screw thread 14 of the bottle. The fingers 26 may be arranged to be a "snap" fit over the flange.

Au advantage of the Figure 2 arrangement is that variations in the design of thread 14 from bottle to bottle are of no concern during the assembly of the apparatus, since these threads are not employed as part of the fixing arrangement. Furthermore the use of the resiliently deformable fingers allows the collar assembly 19 to accommodate a certain amount of variation of the diameter and even the shape of the flangelδ.

Figures 3 a and 3b illustrate yet further optional embodiments of the invention.

In Figure 3 a the collar assembly 19 includes a cup-like member 19a that is similar to member 19a of Figure 1, but the Figure 2 component including resiliently deformable fingers 26 could_, equally well be employed.

One difference between Figure 1 and Figure 3 is that in the latter embodiment the further collar 23 is replaced by a flat, circular disc 27 having formed on its exterior edge surface a screw thread 27a and a central, circular bore 27b that is similar in structure to bore 23 d of further collar 23 in Figure 1. Thus bore 27b includes formed on its surface a screw thread 27d.

The dimensions of the disc 27 and its surface formations are such that it can be screwed into the open end of cup-like member 19a, with the screw thread 27a engaging screw thread 19f thereof. To this end disc 27 includes a pair of driving apertures or depressions 27c formed on diametrically opposed sides of threaded bore 27b.

Assembly of the apparatus 10 according to Figure 3 a and Figure 3b involves the use of a cylindrical tool 28 having a pair of prongs 28a protruding from one end as shown.

The prongs 28a are spaced and sized so that they fit into the apertures 27c of the disc 27. The diameter of tool 28 permits its insertion into the hollow interior of collar assembly 19 and the exterior of the tool 28 is knurled as signified by numeral 28b. The result is a tool that assists in screwing of the disc 27 into the aforesaid hollow interior, such that the entire disc is received internally within this interior.

Following tightening of the disc 27 to secure the filter 17, spacer member 21 and aerosol valve 18 in place the tool 28 is withdrawn to allow completion of the assembly 10.

In the latter regard it is possible, in the Figure 3 arrangement, to employ a modified version 22' of the moveable member.

This form of the moveable member is of cap-like construction whereby it fits over the end of cup-like member 19. To this end the latter is formed with an additional screw thread 19g on its exterior surface adjacent end 19e. Since disc 27 is in use of the Figure 3 apparatus received entirely within cup-like member 19a a screw thread 22'd exists on an interior surface of cap-like member 22' for engagement with the thread 19g.

This form of moveable member 22' may in some circumstances promote more effective sealing, of the apparatus 10, against fluid leakage than the Figure 1 arrangement. On the other hand the cap-like member 22' lacks the reduced . diameter end 22c of the moveable member 22 of Figure 1 , so in order to provide for driving of the aerosol valve 18 the interior of cap-like member 22' includes a depending, conical structure 22j that in use penetrates aperture 27b in disc 27 in order to engage the valve adapter.

The latter is in Figures 3 a and 3b also formed differently from the Figure 1 arrangement, in that a flared frustocone 24a is formed integrally with and merges into pipe 24, the hollow bore of the pipe 24 extending through the frustocone 24a,

Conical structure 22j on extending through the aperture 27b therefore engages frustocone 24a and pushes valve actuator button 18b in dependence on the extent to which cap-like member 22' is screwed onto cup-like member 19a. In this connection pipe 24 extends through a bore hi conical structure 22; and emerges externally of member 22 ' .

Other variants on the principles of the invention will in addition occur to those of skill in the art, and are within the scope of the invention as claimed. Furthermore it is permissible for example to use the design of pipe 24 of Figures 3 a and 3b in the Figure 1 arrangement. All such combinations of features, as described herein, as will occur to the worker of skill are within the scope of the invention.

Claims

1. A biomass extraction apparatus comprising a hollow, fluid-proof receptacle having a hollow neck defining an opening and including one or more neck formations; a filter; an aerosol valve; and a collar assembly defining a hollow chamber and having one or more retention formations that are engageable with one or more said neck formations to permit securing of the collar assembly relative to the neck; to locate the filter to permit filtering of fluid passing via the neck; and to locate the aerosol valve with its actuator accessible via the hollow chamber, the apparatus including an actuator assembly that is operable from outside the chamber to act on- the aerosol valve in the hollow chamber and thereby adjust the degree of opening of the aerosol valve.

2. ^• An apparatus according to Claim 1 wherein the collar assembly includes one or more collar formations defined in the hollow chamber; and a position- adjustable securing member including one or more securing formations that are engageable with the collar formations to permit securing of the filter and the aerosol valve relative to the collar assembly.

3. An apparatus according to Claim 2 wherein the securing member in use protrudes partly from the hollow chamber so as to permit adjustment of its position from outside the collar assembly.

4. An apparatus according to Claim 3 including the securing member in use lies within the hollow chamber.

5. An apparatus according to any of Claims 2 to 4 including a spacer member in the hollow chamber and spacing the filter and the aerosol valve one from the other.

6. An apparatus according to Claim 4 or Claim 5 when dependent from Claim 4 including a tool that is engageable with the securing member so as to permit adjustment of the position of the securing member from outside the collar assembly,

7. Apparatus according to Claim 2 or any preceding claim depending therefrom wherein the collar formations and the securing formations are or include mutually engageable screw threads formed respectively on the collar assembly and the securing member,

8. An apparatus according to any preceding claim wherein the actuator assembly includes a moveable member that is engageable with the aerosol valve via one or more apertures, at least a part of the moveable member protruding on the exterior of the chamber.

9. An apparatus according to Claim 8 wherein the moveable member engages the aerosol valve via an aperture formed in the securing member.

10. An apparatus according to Claim 8 or Claim 9 including a valve adapt :e_' r that in use interconnects the moveable member and the aerosol valve.

11. An apparatus according to Claim 10 wherein the valve adapter includes a hollow conduit permitting flow of fluid via the aerosol valve between the interior and the exterior of the hollow chamber.

12. An apparatus according to Claim 11 wherein the valve adapter includes a widened portion defining the hollow conduit that is connected to an elongate pipe that extends through the moveable member and terminates in an open end externally thereof.

13. An apparatus according to any preceding claim wherein the moveable member is rotatable relative to the remainder of the assembly to adjust the degree of opening of the aerosol valve.

14. An apparatus according to Claim 13 wherein the moveable member is threadedly secured to the remainder of the apparatus.

15. An apparatus according to any preceding claim wherein the fluid-proof receptacle is a bottle.

16. An apparatus according to Claim 15 wherein the bottle is a PET bottle.

17. An apparatus according to Claim 15 wherein the bottle is a transparent PET bottle.

18. An apparatus according to any preceding claim wherein the neck formations include one or more screw threads defined on the exterior surface of the neck of the bottle; and the retention formations are or include complementary screw threads formed on an interior surface of the collar assembly.

19. An apparatus according to any of Claims 1 to 17 wherein the neck formations include a flange formed on the exterior of the hollow bottle adjacent the neck and the retention formations include one or more resiliently deformable clamping members secured to an end of the collar assembly so as to permit resiliently deformable clamping of the neck by the collar assembly.

20. An apparatus according to Claim 19 wherein the neck formations include an annular series of the resiliently deformable clamping members arranged about the periphery of an open end defined in the collar assembly.

21. An apparatus according to Claim 19 or Claim 20 wherein the or each resliently deformable member is or includes a finger extending from the collar assembly.

22. An apparatus according to any preceding claim wherein the actuator assembly in use defines an exterior surface having formed thereon one or more formations assisting manual gripping thereof.

23. Apparatus according to any preceding claim when connected to a source of a pressurised solvent.

24. Apparatus according to Claim 23 wherein the solvent is a hydrofluorocarbon.

25. Apparatus according to Claim 24 wherein the solvent is a C_1-4 hydrofluoroalkane or hydrofTuoroalkene selected from the list comprising trifluoromethane (R-23), fluoromethane (R-41), difluoromethane (R-32), pentafluoroethane (R-125), 1,1,1-trifluoroethane (R-143a), 1,1,2,2- tetrafmoroethane (R- 134), 1,1,1,2-tetrafluoroethane (R- 134a), 1,1-difluoroethane (R-152a), heptafluoropropanes and particularly 1,1,1,2,3,3,3-heptafluoropropane (R-227ea), 1,1,1, 2,3, 3-hexafluoroρroρane (R-236ea), 1,1,1,2,2,3- hexafluoropropane (R-236cb), 1 , 1 , 1 ,3 ,3 ,3 -hexafluoropropane (R-236fa), 1,1,1,3,3- pentafluoropropane (R-245fa), 1,1, 2,2,3 -pentafluoropropane (R-245ca), 1,1,1,2,3- pentafluoropropane (R-245eb), 1,1, 2,3, 3 -pentafluoropropane (R-245ea) and 1,1,1,3,3-pentafluorobutane (R-365mfc) and hydrofluoropropenes including 1,2,3,3,3-pentafluoroρropene (R-1225ye) and 2,3,3,3-tetrafluoroρropene (R-1234). or mixtures thereof.