GB1582758A

GB1582758A - Adsorptive material

Info

Publication number: GB1582758A
Application number: GB43494/77A
Authority: GB
Original assignee: Taikisha Ltd; Toyobo Co Ltd
Current assignee: Taikisha Ltd; Toyobo Co Ltd
Priority date: 1976-10-20
Filing date: 1977-10-19
Publication date: 1981-01-14
Also published as: SE431513B; SE7711774L; FR2368295B1; FR2368295A1

Description

(54) ADSORPTIVE MATERIAL (71) We, TOYO BOSEKI KABUSHIKI KAISHA AND TAIKISHA LIMITED, corporations organised and existing under the laws of Japan, of No. 8 Dojimahamadouri 2-chome, Kita-ku, Osakashi, Osaka-fu, Japan and No. 2-6-1, Nishishinjyuku, Shinjyuku-ku, Tokyo-to, Japan, respectively do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a multi-layer member comprising a plurality of layers of corrugated board each layer being single or double faced with a flat sheet, and containing active carbon fibers useful as an adsorptive material. More particularly, it relates to a multi-layer member of corrugated board made of active carbon fibers having a large adsorptive surface area and a high adsorption rate, which is useful, for instance, as an adsorptive material or a carrier for catalyst.

An object of the present invention is to provide an adsorption apparatus having a small pressure loss and a large treating capacity. Another obje.ct of this invention is to provide a carrier having a large capacity for carrying a catalyst or an absorbing agent and, as the result, a catalytic reactor or an absorbing apparatus of large treating capacity and efficiency.

As an adsorptive layer in an adsorption apparatus, there has hitherto been used a layer filled with granular active carbon. However, such layer, having a slow rate of adsorption, requires to be formed into a considerably large thickness of adsorptive zone, for instance, 20 to 40 cm, and has a defect in that when a fluid is passed through such an adsorptive layer the treated fluid sustains a large pressure loss. Recently there has been proposed a fixed adsorptive layer for which a fibrous active carbon is used. If adequately produced, active carbon fiber has extremely large rate of adsorption, and the thickness of the adsorptive layer can be sufficiently decreased, for example, to a degree of 1 to 8 cm. However, the volume density of the mass of active carbon fiber is generally considerably smaller than that of the granular active carbon, for example, about 0.05 g/cc in the needle-punched non-woven fabric of active carbon fibre and 0.4 g/cc in the mass of granular active carbon. Due to these characteristics there have been cases where the adsorption capacity per fixed volume is not much improved despite the use of an active carbon fibre. Also, when the volume density of the active carbon fibre is increased, the pressure loss is sharply increased.

The present invention provides a multi-layer member comprising a plurality of layers of corrugated board each layer being single or double faced with a flat sheet, and containing active carbon fibre having an equilibrium adsorption amount of benzene of not less than 200 mg/g and the benzene adsorption rate constant of not less than 0.2 min-'.

The active carbon fibre to be used for the present invention is a fibrous active carbon fibre.

Especially, the large rate of adsorption is a property of the active carbon fibre used in the present invention. It is by the use of the active carbon fibres having such characteristics that the object of the present invention. which is to provide the adsorptive layer having large adsorptive capacity small mass transfer zone and small pressure loss. can be attained.

The active carbon fibres having such an adsorbability may be produced by treating material fibres such as cotton, hemp, cellulose regenerated fibre, polyvinyl alcohol fibre, acrylic fibre, aromatic polyamide fibre or petroleum pitch fibre so as to impregnate them with an adequate flame-resisting agent, heating them in an appropriate atmosphere at a temperature not exceeding 400"C so as to make them flame-resistant and further converting them into active carbon at a temperature of 500"C and above.

The preferred material fibers are cellulose fibers, especially polynosic fiber, from the viewpoints of high mechanical properties (strength, etc.) of the resulting active carbon fiber and the easiness of activation at a low temperature. A high strength is an important requirement for the active carbon fiber to prevent its dust formation.

As the above flame-resisting agent, generally compounds containing phosphorus, nitrogen and halogen atoms are preferred. Especially, in the case of the cellulose fiber, the preferred flame-resisting agents are phosphoric acid, ammonium phosphate, tetrakis(hydroxymethyl)phosphonium salt or zinc chloride. The said flame-resisting agent may be mixed in the material fiber or deposited with the surface of fiber by after-treatment The atmosphere in which the flame-resisting treatment is made is preferably in inert gas (e.g. nitrogen), but it may contain oxygen to some degree.

The carbon activation treatment is carried out under an atmosphere containing water vapor, carbon monoxide and carbon dioxide by 5 to 70 % by volume by heating to 500"C or higher. In this case, an adequate activation ingredient may be impregnated first, or an activation may be made by the above method after the preparation of the carbonized fiber under the conventional process.

The multi-layer member containing active carbon fiber of the present invention is preferably that having as high a volume density as possible from the viewpoint of the volume efficiency of the adsorptive capacity, preferably having the volume density of 0.06 g/cc or higher, more preferably of between 0.1 g/cc and higher and 0.3 g/cc and lower. The said sheet material requres to be thin enough for the matter to be adsorbed contained in the fluid to permeate and spread quickly into the interior of the sheet and to have sufficient degree of porosity.

As an area density, a sheet of 10 to 200 g/m2 is preferred. The said sheet material contains active carbon fibers, but may contain fibers of other kind or polymers, etc. in order to improve sheet-retaining property. However, the said sheet material requires to contain at least 10% by weight of active carbon fiber.

An active carbon fiber sheet may be made by a conventional paper-making process from the active carbon fiber alone or from a mixture thereof with wood pulp or a synthetic pulp of polyacrylonitrile or polyethylene. In this case, it is usual to use a binder for paper-making, such as PVA fiber. A blend with other pulp materials gives better reinforcement effect and improved processability on corrugating machine.

Shaping of an active carbon fiber sheet into a corrugated board can be made usually by a conventional corrugating machine. An active carbon fiber sheet is shaped into corrugations through a corrugation roll, and the resulting corrugated sheet (waved sheet) is bonded with a flat sheet on one surface or two surfaces. In bonding, the flat sheet is usually fixed by application of adhesive to the tops of the corrugations, but the application of adhesive is not always necessary. because these layers are fixed on piling up. In case of applying an adhesive, an agent which does not deteriorate the adsorbability to the sheet must be selected. Preferred adhesive is a corn starch mixed with synthetic adhesive.

The wave form of the corrugated sheet which constitutes the corrugated board may be of U-shape or V-shape. Preferably the pitch of waves of the corrugated sheet is so provided as to form 15 to 150 waves per 30 cm length. Preferably the height of the wave is appropriately determined in the range of 1 to 20 mm according to the size of the pitch.

The finer the corrugation pitch is, the smaller are the tubular routes formed in the multi-layer member. This provides a larger pressure loss when the fluid is passed therethrough from the end of the said multi-layer member, while on the other hand a larger transfer velocity of the substance to be treated contained in the fluid to the tube walls of the corrugated board, thus making it possible to shorten the length of the multi-layer member necessary for the treatment. In this case, the substance to be adsorbed is adsorbed in the course of a shorter running distance. The pitch of the corrugation should be so elected as to be most suitable for the particular case in which the above two factors are balanced, and appropriately according to the property of the fluid and the concentration of the substance to be adsorbed. For the purpose of the present invention, the above described pitches are preferred.

Referring to the drawing, an example of the flat sheet bonded to one face of the corrugated sheet is shown as a single-faced corrugated board in Fig. 1, and that of a flat sheet bonded to each face of the corrugated sheet is shown as a double-faced corrugated board in Fig. 2. In whichever of these cases the multi-layer member of the present invention can be formed. In case of forming a multi-layer member by rolling a corrugated board into a form of drum, use of a single-faced corrugated board is preferred.

The multi-layer member of the present invention can be produced by either placing a number of the thus obtained corrugated boards one upon another as shown in Fig. 3 or by rolling a board spirally in multi-layers as shown in Fig. 4. In case of forming a multi-layer member by rolling the board spirally, it is usual to roll at right angles to the direction of run of the pitch of the corrugated sheet, but a rolling with inclination at a certain angle to the direction of run of the wave may be made as in Fig. 5. In this case, the pressure loss may become somewhat large, but such a provision may be desirable because of the increased contact between the substance to be treated and the multi-layer sheet. In case of forming a multi-layer member by piling up a number of corrugated boards, the corrugations require to be laid in substantially the same direction, but may be laid with slight deviations.

The multi-layer member of the present invention is light in weight, having strong shaperetaining property, and possesses adsorbing function, so that it is useful as an adsorptive material to be used in the adsorption apparatus. In the adsorption apparatus, the above multi-layer member is mounted so that the fluid to be treated is supplied to the sectional surface of the multi-layer member, and the fluid to be treated flows along the tubular route formed by the corrugated sheet and the flat sheet of the multi-layer member.

Since the board member of the present invention employs the active carbon fiber having extremely large rate of adsorption, it effects adsorption promptly when the matter to be adsorbed reaches the surface of the sheet. Accordingly, when a small distance between the sheets is set in the range not to provide the pressure loss practically excessive, the thickness of the adsorptive layer can be lessened, and an adsorptive layer having a high adsorption capacity per volume (volume efficiency of adsorption capacity ) can be obtained. The adsorption apparatus of the present invention is particularly effective when the fluid to be treated is gas, but is also usable for liquid.

In order to use the multi-layer member of the present invention as an adsorption apparatus, a plurality of such multi-layer members may be used or a single multi-layer member is divided into zones in an adsorption apparatus which performs adsorption in one zone and desorption in an other, with said adsorption and desorption intermittently changed over, so that the adsorption and the desorption are continuously carried out.

Fig. 6 shows an apparatus wherein multi-layer member 1, formed into multi-layers by rolling up the corrugated board sheet as in Fig. 4, is disposed in such a manner that the fluid to be treated 4 and the purging gas 6 flow along the tubular route in the layers, under which the layer member 1 is continuously rotated in the space between the adsorption zone 3 and the desorption zone 5, so that the adsorption is continuously carried out while the active carbon fiber is being regenerated at the desorption block. The element 2 is a gear for rotating the multi-layer member of corrugated board.

In determining the adequate dimensions of the multi-layer member of the present inven tion, some reviews are made, as follows: Assuming the pressure loss caused at the time when the fluid to be treated is passed through an adsorptive material having the thickness (distance for passage of the fluid) Zm at a wind tunnel velocity u to be At, the relations are represented by the equation: AP = k x u x Zm The length of the mass transfer zone of the material contained in the fluid, i.e. the length of the zone in which the material to be treated is moved to the said structure, is assumed to be Zm. With the decrease in the pitch of the wave of the corrugated board layer of the present invention the amount k is increased and Zm decreased. According to the purpose of use of the multi-layer member, the pitch and the height of the wave may be adequately selected. On the other hand, with regard to k and Zm of the structure of the present invention compared with those of the conventional filled layers of granular active carbon, generally k is remark ably small, but Zm is not so large. In other words, the multi-layer member of the present invention has characteristically an extremely small amount of Zm x k.

In developing the multi-layer member containing active carbon fiber of the present invention the characteristics of the active carbon fiber have been specifically noted, i.e. it possesses extremely large adsorption velocity and it can be easily formed into a thin sheet.

Since such a sheet has a good shapability into a corrugated board, it can be processed into a corrugated board having fine pitches of corrugation. Thus, a structure having extremely large contact area per unit volume is producible. For the reasons described above. the multi-layer member of the present invention can be formed with small Zm in comparison with the similar structure formed with other materials (e.g. the material comprising a sheet deposited with granular carbon).

According to a modified embodiment of the present invention, a catalyst may be carried on the active carbon fiber and formed into the structure of the present invention, by which the use as a catalyst reactor may be possible. The catalyst may be added with the fiber or after formation into the member of the present invention. As the catalyst, there may be exemp lified platinum or noble metal, but is not limited thereto. In case the catalyst is carried on the active carbon fiber, the catalyst area is extremely large and the catalyst efficiency is high.

Further, due to the small pressure loss per unit length in the direction of the flow route, the contact time can be relatively elongated.

According to another embodiment of the present invention, an absorbing agent may be carried on the active carbon fiber and formed into the structure of the present invention, by which the use as an absorbing apparatus may be possible. For example a moisture absorbing agent such as lithium chloride, lithium bromide, may be deposited with the multi-layer member of the present invention and the product utilized as a dehumidifying apparatus. As a preferred active carbon fiber sheet applicable to the above case, there is, for example, a sheet of paper niade by mixing with more than 10% by volume of a thermoplastic fiber and fusing by heat. Generally, the active carbon fiber has a large capacity to carry the absorbing agent. It can carry, for example, the lithium chloride by more than three times the amount of asbestos (weight of absorption per unit weight).

Practical and presently preferred embodiments of the present invention are illustratively shown in the following Examples wherein measurements are made in the following manners: (1) Equilibrium adsorption amount of benzene The equilibrium adsorption amount is measured in accordance with JIS (Japanese Industrial Standard) K-1412. In this JIS, this is termed as a benzene adsorbing power, but it is indicated in modified expression in mg/g herein. The sample for determination is used in an amount of 0.1 to 0.2 g.

(2) Benzene adsorption rate constant: K(min') The benzene adsorption rate constant is calulated by the following equation: enaii= Kt (Il) wherein t is the time (min) and C is the leakage concentration (ppm) at the time (t) of the nitrogen stream containing 500 ppm benzene being passed through a filter layer having a thickness of 20 mm at a velocity of 0.15 m/sec. The constant (K) requires to be in the amount of more than 0.2/min, preferably more than 0.6/min. A specimen of active carbon fiber is used in a form of non-woven fabric having a volume density of 0.05 g/cc.

Example 1 A regenerated cellulose fiber of 2 denier size, used as a precursor fiber, was carbonized and activated to give an active carbon fiber having a benzene adsorption rate constant of 1.6 min~ l The said active carbon fiber, polyacrylonitrile pulp and polyvinyl alcohol fiber were mixed together at the rate of 70,20 and 10% by weight respectively, and the mixture was poured onto a conventional cylinder wet type paper machine, heat pressed in a flat state to give a sheet of active carbon fiber paper having a weight of 50g/m.The resulting sheet of paper was treated with a conventional single-faced corrugator to give a single-faced corru gated board having the pitch of corrugation 3.3 mm and the height of corrugation 1.4 mm.

The said corrugated board was wound up with starch being applied to the tops of the corrugations on a corefilled axle of 20 mm in diameter to build up a column of 600 mm in outer diameter and about 1200 mm in length. The starch used at the time of forming the corrugated board and winding into the column consisted mainly of a corn starch with the addition of a small amount of synthetic starch (LIFE BOND AV-650, trade mark manufac tured by Nissho Kako K.K).

From the above column there was cut out a small columnary body having a length of 105 mm, both sections of the columnar body were ground into flat surfaces, and a columnar layer having the outer diameter of 600 mm and the length of 100 mm was obtained.

Air containing 200 ppm of xylene at 20"C was passed through the said solumnar layer. The result of measurement on the variation by time (break-through curve) of the concentration of xylene in the air on the outlet side at that time is shown in the solid line Fig. 7. The equilibrated adsorption amount obtained frdm the said break-through curve (obtained from the shaded area in Fig. 7), length of the mass transfer zone Zm [obtained from t5, t5" and Z = 10 cm in Fig. 7 by the formula (I)], and the pressure loss at that time as well as the pressure loss coefficient k, are summarized in Table 1.

Zm = z 2(ta;r5) (I) Table 1 Item Measurement amount Pressure loss AP [mmAq] 9.6 k [mmAq/(cm) (cm/sec)] 9.6 x 10-3 Zm [cm] 9.5 Equilibrium adsorption amount [%] 29 Example 2 From the column of Example l (length about 1200 mm) a small columnar body having a length of 15 cm was cut out. and both sections of the columnar body were planed. The end surfaces thereof were dipped by the length of 0.5 cm each in a phenol resin solution and were heated at 100"C to cure. By the use of the thus obtained columnar layer, a rotary adsorption and concentration apparatus as shown in Fig. 6 was made. The desorbing zone 5 of the duct around the axis of ths cylinder (1) is an angle of 44" to the horizontal plane. An air containing 50 ppm of xylene at 23 0C was passed through the adsorbing zone of the apparatus at the flow rate of 60 m3/min. The desorbing zone, the xylene adsorbed to the active carbon fiber of the columnar layer was purged by passing through the air heated at 1200C at the flow rate of 3 m3/ min. During the interval the columnar layer was rotated around the axis of the cylinder as a center at 1 r.p.m. As a result, the pressure loss of the columnar layer was 55 mmAq, and the xylene concentration of the air after the adsorption treatment was 2 ppm. By the said apparatus the xylene was concentrated into 20 times the original volume. Thus, it is sufficient to treat the air of only 3 m3/min containing about 1000 ppm xylene.

Example 3 The columnar layer obtained in Example 1 was impregnated with an aqueous solution of chloroplatinic acid, which was reduced with an alkaline hydrazin solution to carry 5% by weight of platinum catalyst. An air containing 100 ppm of carbon monoxide at 200 was passed through the said platinum carried layer at the flow rate of 10 m3/min. At that time, the pressure loss of the carrier-containing layer was 5.7 mmAq, and the conversion rate from carbon monoxide to carbon dioxide was 93%. The conversion rate is the amount obtained from the following equation: Conversion rate = (1 cn Ci) x 100 (%) wherein Ci is the CO concentration at the inlet and Co is the CO concentration at the outlet.

Example 4 The columnar layer obtained in Example 1 was dipped in an aqueous solution of LiCI whose concentration was adjusted to 0.15 g/ml at 20"C, after which it was lifted up and centrifuged to remove the surplus aqueous solution of LOCI. As a result, the LiCI was carried by 610 g. An air of temperature at 200Cand absolute humidity at 12 g/.kgwas passed through said LiCl carrying layer at the flow rate of 10.1m3/min. The result showed that the absolute humidity of the air on the outlet side of the columnar layer was suppressed to the level not exceeding 1 g/kg for about 10 min.

In conventional active carbon adsorption type exhaust gas treating apparatus there is usually adopted, as shown in Fig. 8, a constitution comprising a pressure vessel 5 having the connections with exhaust gas lead in and out passages la and 1b and regenerated air lead in and out passages 2a and 2b through the changeover valves 3a, 3b, 4a and 4b, respectively, charged with an active carbon layer 6. In said constitution, an exhaust gas containing harmful gas is introduced into the pressure vessel through the exhaust gas lead in passage 1, and the harmful gas is adsorbed to the active carbon layer 6, and then the exhaust gas purified therein is discharged through the exhaust gas lead out passage ib outside. Any choking, increased pressure loss and loss of adsorbing function on the active carbon layer 6 are sensitized with an appropriate means, the changeover valves 3a, 3b, 4a and 4b are changed over between opening and closing and the above induction of exhaust gas is stopped, and instead the regenerated air such as hot wind or steam is introduced through the regenerated gas lead in passage 2a into the pressure vessel 5 to realize regeneration of the active carbon layer 6. Thus, according to the conventional apparatus the constitution is complicated because of the necessities for the expensive pressure vessel, changeover valve, etc., and yet, in order to carry out the gas discharge treatment consecutively, it is necessary to provide a couple of pressure vessels as shown in Fig. 8 and the proportionally increased number of changeover valves, requiring extremely complicated constitution and extremely complicated and troublesome changeover operations. Also, since the active carbon layer is apt to be choked up, the apparatus shows a large pressure loss and has poor efficiency of treating a large volume exhaust gas, and consequently the whole adsorption treatment capacity is lowered. Thus, the conventional apparatuses have had such defects as not to give constantly uniform and stable treating effect.

In order to overcome the defects, it is proposed to construct an active carbon adsorption type exhaust gas treating apparatus comprising a cylindrical rotary adsorbing element formed with fibrous active carbon and resilient material so as to have a number of small size vent holes around the rotary shaft along the axial direction thereof in a manner to rotate together with said shaft, with the constitution of the exhaust gas lead in and out passages and the regenerated air lead in and out passages being connected in a manner not to interfere with the rotation of the element divided around the shaft in sector form so as to have the element pass the adsorbing section and the regenerating section alternately according to the rotation at both ends of the adsorbing element.

Preferably, the rotary adsorbing element may be constituted by the partition board and the corrugated board which are respectively formed by a paper-like material comprising the mixture of the fibrous active carbon and the resilient fibrous material, said partition board and corrugated board being alteranately arranged in multiple layers around the rotary shaft inside and outside of the radial direction thereof.

Also, it may be preferred to constitute the rotary adsorbing element by the partition board formed by a paper-like material comprising a mixture of the fibrous active carbon and the resilient fiber material and the resilient corrugated board of an appropriate material quality, said partition board and corrugated board being alternately arranged in multiple layers around the rotary shaft inside and outside of the radial direction thereof.

Further, it may be preferred to constitute the rotary adsorbing element by the three members of the adsorptive layer comprising a felt-like form of fibrous active carbon, a partition board and a corrugated board, the latter two respectively comprising a resilient and air permeable material or a resilient porous board, said three members being alternately arranged in multiple layers around the rotary shaft inside and outside of the radial direction thereof.

By taking the above constructions, there is provided an extremely simple apparatus capable of effectively carrying out the exhaust gas treatment continuously, and always uniformly and stably, with a single rotary adsorbing element.

An embodiment of such apparatus is illustrated below in reference to Fig. 9 and Fig. 10. In the drawings, the numeral 11 is a cylindrical rotary adsorbing element to be slowly driven rotatively centering on and together with the rotary shaft 12 by an appropriate means (not illustrated), 13a and 13b are the exhaust gas lead in and out passages disposed oppositely at both ends of the adsorbing element 11 in order to lead the exhaust gas from one end of the adsorbing element 11 toward the other end, 14a and 14b are the lead in and out passages for the regenerated air disposed oppositely at both ends of the adsorbing element 11 in order to lead the regenerated air such as the hot wind from one end of the adsorbing element 11 to other end thereof, 15 is a heater provided at the intermediate position of the regenerated air lead in passage 14a and 16 is a harmful gas combustion treatment device provided at the intermediate position of the regenerated air lead out passage 14b. More particularly, the construction of the apparatus is such that the rotary adsorbing element 11 is mounted on a metal case whose two peripheral edges are opened (not illustrated) so as to rotate together with it.Also, on the open ends of the metal case, the open ends of the fixed duct having nearly the same size as those of the metal case are connected by coupling so as not to interfere with rotation of said adsorbing element 11. The inside areas of the two fixed ducts are divided into the large and the small sectors centering on the above rotary shaft 12 by means of the partition boards. The large section of it is used as the above exhaust gas lead in and out passages 13a and and 13b, and the small section of it as the regenerated air lead in and out passages 14a and 14b, respectively. The portion in which the discharge gas is led through the exhaust gas lead in and out passages 13a and 13b becomes the adsorbing section A, and the portion in which the regenerated air is led through becomes the regenerating section B, so that the above adsorbing element 11 passes the adsorbing section A and the regenerating section B alternately according to rotation.

The cylindrical rotary adsorbing element 11 is formed around the rotary shaft 12 along the axial direction of the shaft so as to have a number of small size vent holes 17. To describe this in further detail, the above adsorbing element 11 is constituted in such manner (cf. Fig. 11) that the partition board 18 and the corrugated board 19 which are respectively formed by molding the paper-like materials comprising the mixture of the fibrous active carbon and other fiber materials having resilience such as asbestos fiber by the addition of an appropriate binder, are disposed alternatively in inside and outside of the radial direction around the rotary shaft 12 so as to form the multiple layers, with a number of small spaces formed along the axial direction between the partition board 18 an air such as the hot wind introduced from the other end through the regenerated air lead in passage 14a is forced to run in a number of the vent holes 17 toward one end, and by means of the said regenerated air the harmful gas is separated from the fibrous active carbon mixed in the partition board 18 of the adsorbing element 11 and the corrugated board 19 and is carried to the other end. By this step, the fibrous active carbon is regenerated to recover its force to adsorb and catch favorably the harmful gas contained in the discharge gas as it moves to the adsorbing section A. The adsorbing element 11 is moved sequentially and repeatedly to the adsorbing section without deterioration to its adsorbing function while being always regenerated, so that it adsorbs the harmful gas contained in the discharge gas continuously, evenly and in stabilized condition, and performs the satisfactory gas discharge treatment at all times.

Also, the regenerated air which has adsorbed a large volume of harmful gas through the regenerating section B is to be discharged through the regenerated gas lead out passage 14b after combustion and decomposition of the harmful gas with the combustion treating apparatus 16 into a state free from environmental pollution.

In view of the constitution as described in detail above, the apparatus does not necessitate any complicated constitution or operation such as pressure vessel or changeover of valve as required in the apparatuses of conventional active carbon adsorption system, and it is an extremely handy exhaust gas treating apparatus which is capable of effectively subjecting the harmful gas contained in the exhaust gas to adsorption treatment continuously and yet always in a stabilized condition with a single rotary adsorbing element while said element is being regenerated.

WHAT WE CLAIM IS: 1. A multi-layer member comprising a plurality of layers of corrugated board each layer being single or double faced with a flat sheet, and containing active carbon fibre having an equilibrium adsorption amount of benzene of not less than 200 mg/g and the benzene adsorption rate constant of not less than 0.2 min .

2. The multi-layer member according to claim 2, formed by winding up in a columnar state a single-faced corrugated board containing the active carbon fibre which as an equilibrium adsorption amount of benzene of not less than 200 m/ g and the benzene adsorption rate constant of not less than 0.2 min-'.

3. A multi-layer member according to claim 1 or 2, wherein there are provided at least two layers of corrugated board. one of which being used for adsorbing the matter to be adsorbed contained in a fluid and the other being used for desorbing the adsorbed matter from the layer which adsorbed the matter to be adsorbed, said layers being changed over reciprocally.

4. A multi-layer member according to any preceding claim, impregnated with a catalyst.

5. A multi-layer member according to any preceding claim, impregnated with a moisture absorbing agent.

6. A process for adsorbing materials to be adsorbed contained in a fluid. which comprises supplying the fluid along the route formed by the corrugated sheet and the face sheet of the multi-layer member according to claim I.

7. A continuous rotary type adsorption apparatus provided with a columnar multi-layer member of corrugated board of active carbon fibre according to claim 1 sectioned in into the block for adsorbing the matter to be adsorbed contained in a fluid and the block for desorbing the adsorbed matter respectively in ths direction of rotation of said columnar layer while rotating said columnar multi-layer member.

8. A multi-layer member of corrugated board substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

9. A process for forming a multi-layer member substantially as hereinbefore described with reference to the accompanying drawings.

10. A process for adsorbing materials to be adsorbed contained in a fluid substantially as hereinbefore described with reference to the accompanying drawings.

11. A continuous rotary type adsorption apparatus substantially as hereinbefore described with reference to and as shown in.the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. air such as the hot wind introduced from the other end through the regenerated air lead in passage 14a is forced to run in a number of the vent holes 17 toward one end, and by means of the said regenerated air the harmful gas is separated from the fibrous active carbon mixed in the partition board 18 of the adsorbing element 11 and the corrugated board 19 and is carried to the other end. By this step, the fibrous active carbon is regenerated to recover its force to adsorb and catch favorably the harmful gas contained in the discharge gas as it moves to the adsorbing section A. The adsorbing element 11 is moved sequentially and repeatedly to the adsorbing section without deterioration to its adsorbing function while being always regenerated, so that it adsorbs the harmful gas contained in the discharge gas continuously, evenly and in stabilized condition, and performs the satisfactory gas discharge treatment at all times. Also, the regenerated air which has adsorbed a large volume of harmful gas through the regenerating section B is to be discharged through the regenerated gas lead out passage 14b after combustion and decomposition of the harmful gas with the combustion treating apparatus 16 into a state free from environmental pollution. In view of the constitution as described in detail above, the apparatus does not necessitate any complicated constitution or operation such as pressure vessel or changeover of valve as required in the apparatuses of conventional active carbon adsorption system, and it is an extremely handy exhaust gas treating apparatus which is capable of effectively subjecting the harmful gas contained in the exhaust gas to adsorption treatment continuously and yet always in a stabilized condition with a single rotary adsorbing element while said element is being regenerated. WHAT WE CLAIM IS:

1. A multi-layer member comprising a plurality of layers of corrugated board each layer being single or double faced with a flat sheet, and containing active carbon fibre having an equilibrium adsorption amount of benzene of not less than 200 mg/g and the benzene adsorption rate constant of not less than 0.2 min .