Abstract:
Conventionally air filters are particulate filters composed of fibrous materials in order to remove solid particulates such as dust, pollen, mold, and bacteria from the air. Accordingly, it would be beneficial to provide absorbent filters within such systems in order to address the removal of gaseous impurity components from the circulating air in addition to conventional particulate tillers. It would be further beneficial to provide such absorbent filters in a manner which is compatible with commercial and residential environments that represent the majority of such air circulation systems. It would be further beneficial to provide such absorbent filters in formats that are compatible with new system installations as well as retrofitting to existing system installations.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to gas purification and more particularly to liquid based gas purification systems. 
       BACKGROUND OF THE INVENTION 
       [0002]    Currently, the global environment is seriously threatened. It is essential to find a way to reduce carbon dioxide and greenhouse gas emissions. This invention is a solution to address this problem and reduce global warming 
         [0003]    In chemistry and common usage, a filter is a device that is designed to physically block certain objects or substances while letting others through, depending on their size. Filters are often used to remove solid substances suspended in fluids, for example to remove air pollution, to make water drinkable, and to prepare coffee. Some devices that are called filters may also carry out other processes, such as waste treatment, e.g. a biofilter. Several types of filters are used in chemistry in order to facilitate separation, thereby purifying a liquid or gas. Many filters use gravity, or gravity enhanced by vacuum, i.e. suction, in order to create this separation, often through a funnel-shaped device. Other types of materials may be used to effect separations based on size, similar to filters, such as molecular sieves. The process of passing a mixture through a filter is called filtration. The liquid produced after filtering a suspension of a solid in a liquid is called filtrate, while the solid remaining in the filter is called retentate, residue, or filtrand. 
         [0004]    Purification in the chemical context is the physical separation of a chemical substance of interest from foreign or contaminating substances. Amongst the techniques exploited within chemical purification are affinity purification, absorption, filtration, centrifugation, evaporation, extraction, crystallization, adsorption, smelting, refining, distillation, fractionation, electrolysis, and sublimation. Of these absorption describes the removal of a soluble impurity from a feedstream in which a fluid (the absorbate) permeates or is dissolved by a liquid or solid (the absorbent). Adsorption is a surface-based process while absorption involves the whole volume of the material. 
         [0005]    Within many environments a variety of impurity gases are present within a circulating, or flow or stream, of gases that are desired. For example, air conditioning systems, heating systems etc whilst primarily designed to move air, primarily nitrogen and oxygen, also move other gases which represent impurities such as carbon dioxide, nitrogen oxide, and sulphur dioxide. 
         [0006]    Conventionally air filters are particulate filters composed of fibrous materials in order to remove solid particulates such as dust, pollen, mold, and bacteria from the air. Accordingly, it would be beneficial to provide absorbent filters within such systems in order to address the removal of such impurity components from the circulating air in addition to conventional particulate filters. It would be further beneficial to provide such absorbent filters in a manner which is compatible with commercial and residential environments that represent the majority of such air circulation systems. It would be further beneficial to provide such absorbent filters in formats that are compatible with new system installations as well as retrofitting to existing system installations. 
         [0007]    Currently, the desire to alleviate the problem of global warming has resulted in the environmental concern over a reduction of greenhouse gas emissions from industrial sources. The major greenhouse gases contributing to problem are methane (CH 4 ), carbon dioxide (CO 2 ), nitrous oxide (N 2 O) and halogens such as chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs). Among these, CO 2  is the primary contributor to the problem due to its abundance, and is thus a major target for reduction. To reduce the excessive CO 2  emissions, there is great interest in capturing CO 2  within residential and commercial systems but also for utilizing it as a flooding agent for enhanced oil recovery (EOR) in oil sand operations for example. Based on current technologies, the gas absorption with a chemical reaction process using amine is considered to be the most cost effective and has the best proven operability record for CO 2 . However, the cost of absorption using conventional solvents such as aqueous solutions of monoethanolamine (MEA) is still relatively high. A major reason for the high cost is that the conventional solvents introduce a variety of practical problems including: (i) a high energy consumption for the solvent regeneration; (ii) a high rate of corrosion of the process equipment; (iii) a fast evaporation rate causing high solvent losses; and (iv) a high rate of degradation in the presence of oxygen. All these problems translate into high capital and operating costs. Accordingly, it would be beneficial for these capital and operating costs to be lowered. 
         [0008]    A solution of Ca(OH) 2 , in water, commonly referred to as limewater, is an absorber of carbon dioxide and sulphur dioxide which is in of itself an inert material such that it may be considered for application within a variety of applications, including but not limited to, residential, commercial, vehicle, factories, and agricultural. Limewater may be disposed of through a variety of means including soil neutralization or pH adjustment which is important for agriculture in order to allow plants to absorb from the soil all the elements necessary for growth. As limewater is a solution of Ca(OH) 2  this may be applied to land to reduce soil acidity (raise pH) thereby enhancing uptake of important elements for growth whilst lowering uptake of toxic elements such as manganese, copper, and aluminum. Beneficially calcium supports several enzyme systems within plants as well as improving agricultural yields by improving root and leaf growth conditions as well as microbial activity through the presence of Ca ++  cations. Accordingly, embodiments of the invention provide for a fluid filtering system that is environmentally friendly as the byproduct from the filtering system can be employed within the environment without additional processing, the filtering system itself is reusable. 
         [0009]    Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
       SUMMARY OF THE INVENTION 
       [0010]    It is an object of the present invention to mitigate drawbacks in the prior art relating to gas purification and more particularly to liquid based gas purification systems. 
         [0011]    In accordance with an embodiment of the invention there is provided a device comprising:
   an inlet port for receiving a fluid, the inlet port comprising a partition separating the fluid into first and second predetermined portions;   a reservoir comprising a mixture of an absorber and a solvent;   an absorber pipe having at least an opening at one end into the reservoir such that opening is below the surface of the mixture and comprising a permeable membrane to the fluid disposed so as to intercept the first predetermined portion of the fluid;   a director coupled to the partition for receiving the second predetermined portion of the fluid and to the opening of the absorber pipe;   wherein the device has a first state wherein the fluid is not flowing and the level of the mixture within the absorber pipe is at a first predetermined levels and a second state wherein the fluid is flowing and the level of the mixture within the absorber pipe is at a second predetermined level, the second predetermined level being higher than the first predetermined level.   
 
         [0017]    In accordance with an embodiment of the invention there is provided a method comprising:
   providing an outer shell comprising an internal divider to form upper and lower chambers;   providing an absorber pipe having openings at each end disposed through the internal divider such that the openings at each end are within the upper and lower chambers;   providing at least a first opening disposed within the upper chamber connecting the upper chamber to a first outer environment;   providing at least a second opening disposed within the lower chamber connecting the lower chamber to a second outer environments;   providing within the lower chamber a mixture of an absorber and a solvent disposed such that the opening of the absorber pipe in the lower chamber is below the surface of the mixture.   
 
         [0023]    In accordance with an embodiment of the invention there is provided a method comprising:
   providing an inlet port for receiving a fluid;   providing an chamber coupled to the inlet port for receiving a first fluid;   providing an outlet port coupled to the chamber for receiving a second fluid;   providing an absorber dispenser disposed within the chamber for providing a flow of a mixture across the chamber;   providing a drain for removing the mixture from the chamber; and   flowing the mixture such that the second fluid has a lower concentration of a contaminant than the first fluid.   
 
         [0030]    Within another embodiment of the invention there is provided a method comprising:
   providing a filter comprising:   
 
         [0032]    providing a mechanical frame for supporting an absorber; 
         [0033]    providing the absorber; and
   wherein the filter when inserted into a fluid system with a fluid flow from a first exterior surface of the filter through the filter and away from a second exterior surface of the filter the filter reduces the concentration of a contaminant within the fluid with the fluid flowing after the filter to the fluid flowing prior to the filter.   
 
         [0035]    Within another embodiment of the invention there is provided a filter comprising an absorber comprising a porous material manufactured from a material selected from the group comprising cellulose wood fiber, a foamed plastic polymer, a low-density polyether, polyvinyl alcohol, a polyester, and a xerogel, wherein the filter is intended to filter at least one of carbon dioxide and sulphur dioxide by soaking the absorber within a solution of calcium carbonate. 
         [0036]    Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]    Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein: 
           [0038]      FIG. 1  depicts a fluid absorbent based filter according to an embodiment of the invention; 
           [0039]      FIG. 2  depicts a fluid absorbent based filter according to an embodiment of the invention; 
           [0040]      FIG. 3  depicts a fluid absorbent based filter according to an embodiment of the invention; 
           [0041]      FIG. 4  depicts a fluid absorbent based filter with interconnection to solution reservoir and drain according to an embodiment of the invention; 
           [0042]      FIG. 5  depicts a fluid absorbent based filter with interconnection to solution reservoir and drain according to an embodiment of the invention; 
           [0043]      FIG. 6  depicts a fluid absorbent based filter according to an embodiment of the invention; 
           [0044]      FIG. 7  depicts a fluid absorbent based filter according to an embodiment of the invention; 
           [0045]      FIG. 8  depicts a fluid absorbent based filter according to an embodiment of the invention; 
           [0046]      FIG. 9  depicts a fluid absorbent based filter according to an embodiment of the invention; 
           [0047]      FIG. 10  depicts an absorbent filter according to an embodiment of the invention within safety masks; 
           [0048]      FIG. 11  depicts an absorbent filter according to an embodiment of the invention within safety clothing; and 
           [0049]      FIG. 12  depicts an absorbent filter according to an embodiment of the invention within air filters. 
       
    
    
     DETAILED DESCRIPTION 
       [0050]    The present invention is directed to gas purification and more particularly to liquid based gas purification systems. 
         [0051]    The ensuing description provides exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims. 
         [0052]    A “fluid” as used herein may refer to, but is not limited to, a flow of gas, liquid, gases, and/or liquids within an environment including but not limited to, a duct, a conduit, a room, a building, a pipe, and an enclosed environment. 
         [0053]    An “absorbent” or “absorber” as used herein may refer to, but is not limited to, a material that absorbs by entrapping or chemically reacting with an absorbate wherein the absorbent may be a solid, a liquid, or a gas. 
         [0054]    An “absorbate” or “contaminant” as used herein may refer to, but is not limited to, a component of a fluid which is absorbed by an absorbent wherein the absorbate is at least one of a fluid and a solid. 
         [0055]    Referring to  FIG. 1  there are depicted no flow and flow configurations  100 A and  100 E for a liquid absorbent based filter according to an embodiment of the invention. As depicted in no flow configuration  100 A a filter  180  comprises an inlet  110  and outlet  150  for receiving flow of a gaseous stream. Within the inlet  110  is a tap-off  120  for diverting a predetermined portion of the gaseous stream within the inlet  110  such that the tap-off  120  terminates at the bottom of a permeable duct  140  within the interior of the filter  180 . At the top of the filter  180  an absorber inlet  160  is provided and at the bottom of the filter an absorber outlet  170  is provided. Within the interior of filter  180  a volume of absorber  130  has been provided, e.g. by pouring into the filter  180  via absorber inlet  160 . 
         [0056]    In flow configuration  100 B a gaseous stream  190  is coupled to the filter  180  resulting in a pressure applied to the permeable duct  140  and the absorber  130  via tap-off  120 . The pressure via tap-off  120  results in a column  135  of absorber  130  being formed within the permeable duct  140 . Accordingly, the gaseous stream  190  coupled to the bottom of the column  135  via tap-off  120  will permeate through the column  135  whilst that portion of gaseous stream  190  within inlet  110  not tapped off is coupled into the chamber within filter  180  wherein due to the pressure created by the gaseous stream  190  it will flow through the permeable duct  140  permeating through column  135 , except for that portion of column  135  which may be left unfilled due to design at the target air flow of gaseous stream  190  or variations in air flow. Accordingly, the design may be implemented such that a predetermined portion of the gaseous stream  190  passes through the absorber  130 . 
         [0057]    For example, absorber  190  may be a saturated solution of calcium hydroxide, Ca(OH) 2 , in water. At 25° C. Ca(OH) 2  is soluble in water at 1.5 gdm −3  (14 mgl −1 ) and decreases with increasing temperature and increases with acidity (pH). A calcium hydroxide solution readily absorbs carbon dioxide (CO 2 ) readily from air, giving a milky solution. This is due to the insoluble suspension of calcium carbonate formed by chemical reaction given by Equation (1) below. If excess CO 2  is added then a second reaction occurs as given by Equation (2). 
         [0000]      Ca(OH) 2 ( aq )+CO 2 ( g )→CaCO 3 ( s )+H 2 O( l )  (1)
 
         [0000]      CaCO 3 ( s )+H 2 O( l )+CO 2 ( g )→Ca(HCO 3 ) 2 ( aq )  (2)
 
         [0058]    Additionally, sulphur dioxide (SO 2 ) can be cleaned from exhaust gases using a solution of calcium hydroxide wherein the SO 2  is trapped as a precipitate via the chemical reaction given by Equation (3) below. 
         [0000]      Ca(OH) 2 ( aq )+SO 2 ( g )→CaSO 3 ( s )+H 2 O( l )  (3)
 
         [0059]    Alternatively, a two-stage process for sulphur dioxide (SO 2 ) may be employed wherein initially calcium carbonate reacts with the SO 2  to generate calcium sulphate and carbon dioxide, wherein the carbon dioxide is cleaned using the calcium hydroxide solution such as described via Equations (4A) and (4B) below. 
         [0000]      CaCO 3 ( s )+SO 2 ( g )→CaSO 3 ( aq )+CO 2   (4A)
 
         [0000]      Ca(OH) 2 ( aq )+CO 2 ( g )→CaCO 3 ( s )+H 2 O( l )  (4B)
 
         [0060]    Accordingly where a saturated solution of calcium hydroxide is employed as absorber  130  both carbon dioxide and sulphur dioxide can be absorbed from gaseous stream  190  resulting in their forming precipitates within the absorber  130  directly as well as through other combinational sequences. The absorber  130  may be added to the filter  180  through absorber inlet  160  and removed via absorber outlet  170 . Optionally, depending upon the location of the filter  180  within the air ducts, furnace exhaust or other air system elements absorber inlet  160  and absorber outlet  170  may be coupled via piping/tubing to remote access points and/or be coupled to a system that periodically charges/discharges the filter  180  providing eased maintenance and use. 
         [0061]    As noted the solubility of Ca(OH) 2  within water increases with acidity as well as reduced temperature. Accordingly, within residential environments the acidity of the solution within which the Ca(OH) 2  is dissolved may be increased through the addition of one or more weak acids, such as acetic acid, citric acid, and sorbic acid which may be found within many residential environments already as part of the kitchen cupboard as part of baking accessories. Other acids which may be considered include lactic acid and phosphoric acids, the latter being typically found in domestic rust cleaning compounds. In commercial environments other acids may be considered which are stronger such as hydrochloric where professional trained staff would be responsible for the maintenance of the systems containing the Ca(OH) 2  solution and adding acid to such systems. 
         [0062]    Now referring to  FIG. 2  there is depicted a liquid absorbent based filter  200  according to an embodiment of the invention. As depicted the filter  200  comprises a body  230  with first and second chambers  200 A and  200 B linked by a tube  260  within inner wall  270 . The filter  200  being depicted installed within a wall  210  and a supporting member  220 , e.g. a floor. Within the second chamber  200 B an absorber  280  is disposed which can be added to the filter  200  via inlet port  295  and drained via outlet port  290 . Disposed within the second chamber  200 B are first vents  240  whilst disposed within the first chamber  200 A are second vents  250 . Accordingly, as depicted air flows from first vents  240  into second chamber  200 B wherein it passes through the absorber  280  or through the tube  260  which is permeable and absorber column  285  which is raised as a result of the air pressure differential between the second chamber  200 B and first chamber  200 A. Accordingly, the air then flows into first chamber  200 A and out through second vents  250 . 
         [0063]    It would be evident to one skilled in the art that where absorber  280  is calcium carbonate solution then carbon dioxide and sulphur dioxide within the flowing air may react with the absorber  280  removing them from the air flow. Periodically the absorber  280  may be replaced via inlet  295  and outlet  290 . As depicted filter  200  is designed for fitting within a residential or commercial environment between floors but it would be evident that variants of filter  200  may be designed for fitting within an air duct, forced air heating system, or other element of an air distribution system within a commercial or residential environment. 
         [0064]    Now referring to  FIG. 3  there is depicted a liquid absorbent based filter  300  according to an embodiment of the invention. As depicted the filter  300  comprises a body  330  with first and second chambers  300 A and  300 B linked by an opening within inner wall  370 . The filter  300  being depicted installed within a wall  310  and a supporting member  320 , e.g. a floor. Within the second chamber  300 B an absorber  380  is disposed which can be added to the filter  300  via inlet port  395  and drained via outlet port  390 . Disposed within the second chamber  300 B are first vents  340  whilst disposed within the first chamber  300 A are second vents  350 . Accordingly, as depicted air flows from first vents  340  into second chamber  300 B wherein a portion of the airflow comes into contact with the absorber  380 . Accordingly, the air then flows into first chamber  300 A and out through second vents  350 . 
         [0065]    It would be evident to one skilled in the art that where absorber  380  is calcium carbonate solution then carbon dioxide and sulphur dioxide within the flowing air may react with the absorber  380  removing them from the air flow. Periodically the absorber  380  may be replaced via inlet  395  and outlet  390 . As depicted filter  300  is designed for fitting within a residential or commercial environment between floors but it would be evident that variants of filter  300  may be designed for fitting within an air duct, forced air heating system, or other element of an air distribution system within a commercial or residential environment. 
         [0066]    Now referring to  FIG. 4  there is depicted a system  400  wherein a filter  410  such as described above in respect of  FIGS. 1 through 3  respectively is coupled at its inlet  495  via first valve  440  and pump  430  to an absorber reservoir  420 . The outlet  490  is coupled via second valve  450  to second pump  460  and therein via particulate filter  470  to sink  480 . Sink  480  may for example be a reservoir that is periodically drained and disposed of or it may be a drain into a waste system such as that supporting residential and commercial buildings provided by local authorities. Alternatively sink  480  may be combined with particulate filter  470  such that the CaSO 3  and/or CaCO 3  may fall to the bottom of the combined system as sediment wherein it is removed and the filtered absorber is then drained away. Optionally, sink  480  may be linked back to absorber reservoir  420  to form a closed loop system. In such a loop-back configuration the absorber reservoir  420  may include sensors for monitoring acidity and add additional acid and/or calcium carbonate together with water to maintain the absorber within a predetermined pH range. 
         [0067]    Now referring to  FIG. 5  there is depicted a filter system  500  according to an embodiment of the invention for use within a duct comprising first and second sections  500 A and  500 B which are coupled to first and second access ports  515 A and  515 B respectively of the filter  510 . The filter  510  is coupled at its inlet  595  via first valve  540  and pump  530  to an absorber reservoir  520 . The outlet  590  is coupled via second valve  550  to second pump  560  and therein via particulate filter  570  to sink  580 . The sink  580  being coupled back to absorber reservoir  520  via third valve  525  in a closed loop system. Also as depicted inlet  595  of the filter  510  is coupled to shower head  5100  which provides a shower of absorber  5000  within the filter  510  through which the air is flowing. 
         [0068]    Now referring to  FIG. 6  there is depicted a fluid absorbent based filter  600  according to an embodiment of the invention. As depicted filter  600  comprises an outer body  610  which supports inner body  620  within which there is absorber fluid  680 . Filter  600  being supported by building member  630  and having first vent  650  into outer body  610  within lower building environment  600 B and a second vent  690  from the outer body  610  to the inner body  620  so that fluid from the lower building environment  600 B flows to upper building environment  600 A via third vents  660  in the inner body  620  and fourth vents  670  in the outer body  610 . The absorber fluid  680  absorbing predetermined components of the fluid flowing from the lower building environment  600 B to upper building environment  600 A according to the selection of absorber fluid  680 . 
         [0069]    Referring to  FIG. 7  there is depicted a fluid absorbent based filter assembly  700  according to an embodiment of the invention and variant filter  750 . Filter  700  comprises a converter  705  disposed within a fluid exhaust  710  wherein the fluid post converter  705  are coupled to a filter  725  before being exhausted through exhaust  720 . Disposed at the top and bottom of filter  725  are inlet  715  and outlet  730  wherein absorber fluid may be disposed within the filter  725  via inlet  715  and emptied via outlet  730 . Accordingly, the absorber fluid as described in respect of the embodiments of the invention absorbs elements of the fluid flowing within fluid exhaust  710  so that they are reduced in the exhaust  720 . Variant filter  750  is similarly disposed after fluid exhaust  710  and fluid post converter  705  but now comprises outer body  770  and cartridge  760  which fits within outer body  770 . Cartridge  760  comprises a solid body with permeable membranes  755  that allow fluids flowing within fluid exhaust  710  to flow into and out of the cartridge  760  wherein components of the fluids flowing are absorbed by the absorber fluid  765  within the cartridge  760 . Accordingly, it would be evident to one skilled in the art that cartridge  760  may be removed from the outer body  770 , emptied, and re-filled with absorber fluid  765 . Optionally, cartridge  760  may be cleaned prior to re-filling. According to an embodiment of the invention fluid converter  705  may be a catalytic converter within the exhaust system of a motor vehicle. 
         [0070]    Now referring to  FIG. 8  there is depicted a fluid absorbent based filter according to an embodiment of the invention in cross-section view  800  and perspective view  850 . As depicted a fluid flow is present within a fluid conduit  805  wherein a portion  810  is separated from it and channeled to a fluid body  815  wherein it passes through a structure  820 . Disposed within the body  850  of the filter a particulate filter  825  filters particulates from the remainder of the fluid flow present within the fluid conduit  805  not redirected visa portion  810 . The fluid flow directed by portion  810  to fluid body  815  passes through absorber fluid  830  wherein it combines with the fluid passing through particulate filter  825  into the output duct  835 . Accordingly, a portion of the fluid elements present within the fluid flow are absorbed by the absorber fluid such as described supra in respect of other embodiments of the invention. It would be evident to one skilled in the art that a fluid absorbent based filter as described in respect of  FIG. 8  may be employed in a variety of systems including an air conditioning system within a semi-closed environment wherein repeated circulation of fluid would result in the fluid passing through the fluid absorbent based filter repeatedly. 
         [0071]    Referring to  FIG. 9  there is depicted a fluid absorbent based filter according to an embodiment of the invention in assembled form  900  and component form  950 . The fluid absorbent based filter comprises an outer body  940  and inner cartridge  920  that allows an absorber fluid  930  to be housed within the inner cartridge  920  via port  910 . As depicted in component form  950  the inner cartridge  920  may be separated from the outer body  940  allowing the inner cartridge  920  to be emptied of absorber fluid  930  and refilled prior to insertion back into outer body  940 . This emptying and refilling being made via port  910 . 
         [0072]    Within the embodiments of the invention described supra in respect of  FIGS. 1 through 9  an absorber fluid is employed to absorb fluid elements from a fluid flow. For example, the absorber may be a saturated solution of calcium hydroxide, Ca(OH) 2 , in water allowing carbon dioxide and sulphur dioxide to be partially removed from an airflow such as from a furnace or central air heating system for example. 
         [0073]    Now referring to  FIG. 10  there are first and second safety masks  1000 A and  1000 B respectively according to embodiments of the invention employing fluid absorbent filters  1010 . As depicted a fluid absorbent based filter  1010  according to an embodiment of the invention supports inner body  1020  within which there is absorber fluid  1080 . Air vents  1070  provide for ingress/egress of air to the filter  1010  such that the air drawn through the filter  1010  then passes through the fluidic barrier membranes  1060  on the inner body  1020  such that the absorber fluid  1080  may absorb predetermined components of the fluid passing through the filter  1010 . Fluidic barrier membrane  1060  allows flow of air through but prevents passing of the absorber fluid  1080  such that the first and second safety masks  1000 A and  1000 B respectively may be transported, shipped, picked up, put down etc. without the absorber fluid  1080  spilling out from the inner body  1020  or the assembly  1010 . Inner body  1020  may be emptied/refilled through cap  1040  alternatively it may be a sealed cartridge for removal/disposal prior to purchase/insertion of another. 
         [0074]    Within another embodiment of the invention the inner body  1020  may be a sponge-like material, such as for example those made from cellulose wood fibers, foamed plastic polymers, low-density polyethers, polyvinyl alcohol (PVA, very dense, highly absorbent material with no visible pores and biodegradable), a polyester, or a xerogel. In this instance the assembly  1010  provides mechanical support etc. Accordingly, such absorber based inner bodies  1020  may be soaked in a solution of calcium hydroxide which will then absorb the carbon dioxide forming calcium carbonate. The absorber may then be disposed of or in other embodiments of the invention it may be washed and then “re-loaded” with calcium carbonate solution. It would be evident that such air filters provide a low cost safety mask for individuals in environments with high carbon dioxide levels or potentially high carbon dioxide levels. 
         [0075]    Referring to  FIG. 11  there are depicted absorbent filters according to embodiments of the invention employed within safety clothing. As depicted first to third safety uniforms  1100 A to  1100 C respectively have upon them fluid absorbent filters  1110 . As depicted a fluid absorbent based filter  1110  according to an embodiment of the invention supports inner body  1120  within which there is absorber fluid  1180 . Air vents  1170  provide for ingress/egress of air to the filter  1010  such that the air drawn through the filter  1110  then passes through the fluidic barrier membranes  1160  on the inner body  1120  such that the absorber fluid  1180  may absorb predetermined components of the fluid passing through the filter  1110 . Fluidic barrier membrane  1060  allows flow of air through but prevents passing of the absorber fluid  1180  such that the first to third safety uniforms  1100 A to  1100 C respectively may be transported, shipped, picked up, put down etc. without the absorber fluid  1180  spilling out from the inner body  1120  or the assembly  1110 . Inner body  1120  may be emptied/refilled through cap  1140  alternatively it may be a sealed cartridge for removal/disposal prior to purchase/insertion of another. 
         [0076]    Within another embodiment of the invention the inner body  1120  may be a sponge-like material, such as for example those made from cellulose wood fibers, foamed plastic polymers, low-density polyethers, polyvinyl alcohol (PVA, very dense, highly absorbent material with no visible pores and biodegradable), a polyester, or a xerogel. In this instance the assembly  1110  provides mechanical support etc. Accordingly, such absorber based inner bodies  1120  may be soaked in a solution of calcium hydroxide which will then absorb the carbon dioxide forming calcium carbonate. The absorber may then be disposed of or in other embodiments of the invention it may be washed and then “re-loaded” with calcium carbonate solution. 
         [0077]    Alternatively those regions  1150  of the first to third safety uniforms  1100 A to  1100 C may be formed from a flexible inner body  1120  soaked and/or impregnated with absorber fluid  1180 . These may solely exterior on the first to third safety uniforms  1100 A to  1100 C or in other embodiments of the invention may provide breathable areas of the first to third safety uniforms  1100 A to  1100 C in combination with one or more other barrier materials designed to provide the required chemical, heat, vapour protection for the individual wearing the safety uniform. 
         [0078]    It would be further evident that the concepts described supra in respect of  FIGS. 10 and 11  may also be employed in the formation of air filters either using a combination of a sponge-like materials soaked and/or impregnated with absorber fluid  1180 . In such embodiments assembly  1110  provides mechanical support/security as well as in some applications providing the means for inserting/mounting the air filter within an air system such as depicted by first to third air filter assemblies  1200 A to  1200 C respectively in  FIG. 12 . 
         [0079]    A solution of Ca(OH) 2  in water, commonly referred to as limewater, is an absorber of carbon dioxide and sulphur dioxide which is in of itself an inert material such that it may be considered for application within a variety of applications, including but not limited to, residential, commercial, vehicle, factories, and agricultural. Limewater may be disposed of through a variety of means including soil neutralization or pH adjustment which is important for agriculture in order to allow plants to absorb from the soil all the elements necessary for growth. As limewater is a solution of Ca(OH) 2  this may be applied to land to reduce soil acidity (raise pH) thereby enhancing uptake of important elements for growth whilst lowering uptake of toxic elements such as manganese, copper, and aluminum. Beneficially calcium supports several enzyme systems within plants as well as improving agricultural yields by improving root and leaf growth conditions as well as microbial activity through the presence of Ca ++  cations. Accordingly, embodiments of the invention provide for a fluid filtering system that is environmentally friendly as the byproduct from the filtering system can be employed within the environment without additional processing, the filtering system itself is reusable. 
         [0080]    It would be evident to one skilled in the art that alternative embodiments of the invention may provide additional fluid elements to the filtering system, such as for example allowing the addition of an air freshener and/or scent to the fluid passing through the system(s). In many environments partial processing of the fluid flowing may be considered rather than all fluid flowing as the system recirculates. 
         [0081]    Within the embodiments of the invention it would be evident to one skilled in the art that where a cartridge or removable/insertable element forms part of the overall filter system then preventing the absorber fluid from escaping the removable/insertable element may exploit one or more techniques within the prior art including, but not limited to, non-return valves, spring loaded valves that are opened as inserted into filter body, permeable membranes, moveable valves which open/close during insertion/removal, and twistable valves which open/close during insertion/removal. 
         [0082]    It would be evident to one skilled in the art that the methods and devices described above in respect of filtering may be applied to other absorbers and fluids without departing from the scope of the invention. 
         [0083]    The foregoing disclosure of the exemplary embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents. 
         [0084]    Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.