MXPA00008346A - Process for effecting mass transfer between a liquid phase and a gaseous phase - Google Patents

Abstract

A process for effecting mass transfer between a liquid phase and a gaseous phase in a filled-type column comprising an external shell which accommodates at least one filler-containing basket wherethrough the phases are caused to flow in countercurrent relationship, advantageously comprises the step of feeding the gaseous phase to the at least one basket through a gas-permeable surface thereof which is larger than the basket cross-section, preferably in a prevailing radial flow direction.

Description

PROCESS TO MAKE A MASS TRANSFER BETWEEN A LIQUID PHASE AND A GASEOUS PHASE Field of the Invention The present invention relates to a process for effecting a mass transfer between a liquid phase and a gas phase in a refillable column wherein said phases flow in a countercurrent relation. In the detailed description which follows and in the following Claims, the term "refillable column" is to be understood as - in general - an apparatus having, placed therein, a variety of elements of various shapes and sizes ( filling) on whose surfaces it is originated that a liquid phase and a gas phase make contact with each other to be able to effect a mass transfer; This type of apparatus is widely used in chemical plants, for example, to decompose, absorb, distill and purify chemicals. The present invention also relates to a refillable column for implementing the above process and to a method for modifying a preexisting column for conversion to a refillable column according to the present invention. In the description described below and in the Subsequent claims, the term "modify" should be understood as the in-situ modification of a pre-existing plate or refillable column to improve its performance and, for example, to increase its capacity and / or its efficiency in mass transfer between the liquid phase and the gas phase, as well as to reduce its energy consumption.

Antecedents of the Invention. As is known, in the field there is a growing need to provide processes that are easy to implement, which can effect a mass transfer between a liquid phase and a gas phase in a simple and efficient way, with low costs of investment and operation and with low energy consumption. In order to satisfy the above requirements, processes have been proposed in the field to effect a mass transfer in which a liquid phase and a gas phase flow through a refillable column in a downward and upward direction (considerably axial), respectively. Although they are simple to implement, said prior processes are surrounded by problems that arise primarily from the large pressure drop experienced by the gas phase as it passes through the fill. In fact, the filling is placed inside considerably cylindrical columns which have a large height-to-diameter ratio whose intention is to ensure an interface contact of sufficient duration for the phases to increase mass transfer. Consequently, when flowing through a filler, the gas phase undergoes a significant pressure reduction (pressure drop), which causes limitations in the amount of gas that can be fed to the column, thus, the capacity of the column is reduced. For reasons of this pressure drop, the flow range of the gas phase that feeds the column must be kept below predetermined values, reaching them would result in the appearance of an undesirable "flood" phenomenon, where it floods the column with the liquid phase which stops in its downward movement due to frictional friction! of the gas phase. It will be appreciated that in this condition the column will no longer be operable, because the transfer of mass drops to virtually nothing. In other words, the large pressure drop of the gas phase when passing through the backfill is a limiting factor of the gas phase flow rate through the column designed to implement the prior prior art processes and hinders a transfer of effective mass between the phases. According to the prior art and to counteract the pressure drop in the gas phase and, thus, increase the capacity of the fill type columns, some special fillers having a high vacuum ratio have been proposed, i where the current of the gas phase is not subjected to large pressure drops. As these fillers allow the flow range of the gas phase to feed the column to increase in some way, they have not succeeded in providing a fully satisfactory mass transfer between the phases, since the pressure drop of the Gas phase through the column is still quite significant, as are the operational difficulties due to the aforementioned flood phenomenon. 10 Columns of the so-called plate type, ie, provided with a variety of perforated plates fitted horizontally within the column, have been proposed as an alternative to the filler type columns. In this case, the process for effecting mass transfer 15 between the liquid and gaseous phases comprises mixing the phases together in the plates, the plates being normally designed to increase the contact of the phases themselves. It has been found that plate type columns are suitable for low flow range applications, but they are subject to flooding, which does not allow for more effective mass transfer between the liquid and gas phases. It is due to the above disadvantages that the processes of the prior art to effect a mass transfer between a liquid phase and a gas phase have been unsatisfactory. so far, both in terms of a total efficiency of the transfer between the phases, the energy consumption and the operation and investment costs of the columns used to implement these processes (which are, as mentioned before, being surrounded by several limitations). All this, despite the fact that this technology has been used in a variety of chemical applications for years and that the aforementioned need has been felt in an increased way in the field.

Summary of the Invention. The problem is that the fundamental reason of the present invention is to provide a process to effect a mass transfer between a liquid phase and a gas phase, wherein said process provides a highly efficient transfer between the phases in a simple and effective manner. , with low investment and operating costs and low energy consumption. This problem is solved, according to the present invention, by means of a process as indicated above to effect a mass transfer between a liquid phase and a gas phase within a refillable column comprising an external liner that accommodates at least a reservoir containing the filling where said phases flow in countercurrent, the process of which is characterized in that it comprises the step of feeding said gaseous phase to at least one reservoir through a surface of a gas-permeable reservoir which is larger than the transverse deposit. In this way, by causing the gaseous phase to flow through a penetration surface of at least one reservoir which is conveniently made larger than the transverse reservoir, a corresponding reduction in the pressure drop of the flow range is obtained. which will increase - at least at the same time - to operate at slower speeds than the prior art processes, thereby significantly increasing the mass transfer between the phases. The benefits presented in terms of improved efficiency of mass transfer are 'a larger and larger penetration surface for the gas phase. In this regard, the above problem is solved in particular, by means of a process for effecting a mass transfer between a liquid phase and a gas phase within a refillable column which comprises an external liner that accommodates at least one reservoir that contains filler whose cross section is smaller than the cross section of said liner, said process comprises the steps of: - Feeding said liquid phase and gaseous phase in said refillable column; - causing the liquid phase to flow through at least one reservoir in a substantially axial direction; - causing the gas phase to flow through at least one reservoir in a prevailing radial direction; - Extract said liquid phase and gas phase from said refillable column. With the process of the present invention and, in particular, by causing the gas phase to flow through the fill in a prevailing radial direction - rather than in an axial direction as taught in prior art processes - the penetration surface or in the process, it can expand drastically to positively and effectively increase the mass transfer between the phases and, consequently, significantly increase the capacity of the column designed to implement this process on a column of comparable size which operates according to the aforementioned processes of prior art. In other words, for a given capacity, the column that implements the process of the present invention can be made considerably smaller than the column of the prior art. This arises mainly because the pressure drop at which the gas phase is subjected to flowing radially through the filling can be considered trivial compared to the pressure drop involved in going through the filling in the axial direction, such that the process of the present invention can conveniently be carried out in gas flow ranges higher than those of the prior art, before the occurrence of such undesirable phenomenon as flooding, thereby increasing the mass transfer between the liquid phase and the gas. In particular, the process of the present invention can virtually eliminate - in an extremely simple and effective way - the difficulties of the pressure drop and the limited flow range of the gas phase through the column, which allows operate at desirable volumes and velocities of gas and liquid flows for optimum utilization of the area of the exchange surface of the fill to effect mass transfer. Conveniently, due to this process, a highly efficient mass transfer between phases can now be achieved by using a refillable column which performs more efficiently and involves low investment and operating costs and low energy consumption. The fact that the mass transfer between the phases can be significantly improved by flowing the gas phase in a radial direction prevailing through the filling, is in strong contradiction with the constant teachings of the prior art, that a cross-sectional flow of the gaseous phase relative to the liquid phase is less convenient from the point of view of mass transfer than an axial flow of the phases in a true countercurrent relation. Furthermore, since the chemical / physical conditions and processes which are responsible for the mass transfer between the phases may vary considerably with the type of flow, the benefits of the process according to the present invention were not all predictable to Priori It was only the research work carried out by the Applicant that he unexpectedly discovered, that by causing the gas phase to flow in a prevailing radial direction, countercurrent to the considerably axial flow of the liquid phase, the driving force responsible for the mass transfer between the phases could act much more efficiently in a true countercurrent flow and, therefore, the effectiveness and intensity of the mass transfer could be increased conveniently. In particular, satisfactory results have been obtained by causing the gas phase to flow through at least one deposit in radial, axial-radial or transverse directions in a considerable manner. It is preferable that the prevailing radial flow of the gas phase through at least one reservoir is alternatively of the centrifugal type, centripetal or centrifugal and centripetal. In particular, in a convenient embodiment of the present invention, it is caused that the liquid phase and the gas phase flow in at least one reservoir through a variety of adjacent superimposed zones, feeding the liquid phase and the phase of gas to an upper zone and a lower zone respectively of at least one reservoir, and extracted from a lower zone and an upper zone thereof, respectively. By dividing the filling into a variety of zones so that they are passed through the gas phase in a prevailing radial direction, an increase in the radial component of the gas flow is obtained, with the consequence that it is possible to further increase the flow range of the gas phase and, therefore, improve the mass transfer between the phases and with them the capacity of the column used to implement this process. Alternatively, the same result can be obtained by causing the liquid phase and the gas phase to flow in a substantially axial, radial direction prevailing respectively through a variety of overlapping deposits containing filler. Conveniently, according to the last mentioned modality, the process according to the present invention also comprises the step of: - Gathering and redistributing said liquid phase among the successive deposits. In this way, it is possible to keep all the filling constantly swept by the liquid phase, therefore, the latter is prevented from flowing down through preferential paths which only sweep local areas of the fill, resulting in an area of the much less effective surface is available for mass transfer.

Preferably, it is caused that the gas phase flows radially through contiguous zones of at least one reservoir or through successive reservoirs, in opposite directions, such that a zigzag flow path for the reservoir is provided. gas phase inside the column, which has been found to be convenient from the point of view regarding the construction. To implement the above process, the present invention conveniently provides a refillable column for effecting a mass transfer between a liquid phase and a gas phase, which comprises: - An external liner; - At least one reservoir for containing the filling that extends inside said liner, at least one reservoir which is penetrated through said phases in a countercurrent relation; - respective means for feeding said liquid phase and said gas phase to said column; - respective means for extracting said liquid phase and said gaseous phase from said column; The column is characterized in at least one reservoir provided with a gas permeable surface, to pass the gas phase, which is larger than its cross section. Preferably, the column according to the present invention is characterized in that at least one reservoir has a smaller cross section than the cross section of the liner and has opposite side walls which are gas permeable and in which also comprises means for originating that said gas phase flows through at least one reservoir in a prevailing radial flow. According to a preferred embodiment, the column conveniently comprises: - An external liner, of substantially cylindrical shape; - At least one annular reservoir for containing the filling, which is placed coaxially within said liner and includes opposed inner and outer cylindrical walls respectively, permeable to gas, at least one reservoir which is penetrated through said Liquid phase in a direction of axial flow; - A first free space defined between an inner wall of the liner and said outer wall of the tank; - A second free space defined inwardly of said inner wall of the tank; - respective means for feeding said liquid phase and said gas phase to said column; - Means for causing at least a larger portion of said gas phase to flow through at least one reservoir, from said first free space to said second free space or vice versa; - respective means for extracting said liquid phase and said gaseous phase from said column. According to a more preferred embodiment, the column conveniently comprises: - An external lining; - At least one reservoir for containing the filling, placed inside said liner in coaxial form and supplied with opposed, preferably flat, side walls, which are permeable to gas, at least one reservoir which is penetrated through said phase liquid in a direction of substantially axial flow; - First and second free spaces, placed opposite each other and defined within an interior wall of said liner and said side walls of the tank; - respective means for feeding said liquid phase and said gas phase to said column; - Means for causing at least a larger portion of said gas phase to flow through at least one reservoir, from said first free space to said second free space or vice versa; - respective means for extracting said liquid phase and said gaseous phase from said column. According to another aspect, the present invention provides a method for modifying a column to effect a mass transfer between a liquid phase and a gas phase, either of the filling type or of the type of plates, which method is characterized in that it comprises the step of: - Providing, within said column, at least one reservoir for containing a filling and having a gas permeable surface, to pass the gas phase, which is greater than its cross section. Thanks to the previous method of modifying an existing column, a process can be obtained to effect a mass transfer between a liquid phase and a gaseous phase, which allows to provide a high transfer rank between the phases in a simple and effective way, at low investment and operating costs and with low energy consumption. Other features and advantages of the present invention will become more apparent from the following description of a mode of the process according to the present invention, determined by means of a non-limiting example with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Figure 1 is a view of how a longitudinal section of a first modality of a refillable column is constructed, either from an original design or by modifying a traditional column, to implement the process according to the present invention; Figure 2 is a view of a longitudinal section of the column shown in Figure 1, taken along the line 11-1 in Figure 1; Figure 3 is a view of how a longitudinal section of a second embodiment of a refillable column is constructed, either from an original design or by modifying a traditional column, to implement the process according to the present invention; Figure 4 is a view of a longitudinal section of the column shown in Figure 3, taken along the line IV-IV in Figure 3; Figure 5 is a view of how a longitudinal section of a third embodiment of the refillable column is constructed, either from an original design or by modifying a traditional column, to implement the process according to the present invention; Figure 6 is a view of a longitudinal section of the column shown in Figure 5, taken along the line VI-VI in Figure 5.

Detailed Description of the Invention With reference to Figures 1-6, shown generally with 1, there is a refillable column for effecting a mass transfer between a liquid phase and a gas phase, according to the present invention. Column 1 comprises an outer liner 2, at least one reservoir 3 that extends inside the liner 2 to receive a filling 4, respective means 5 and 6 for feeding a liquid phase and a gaseous phase in the column 1, and respective media 7 and 8 to extract the liquid phase and the gas phase of column 1. Means 5 and 7 for feeding, respectively, extracting the liquid phase from column 1 which generally comprises conduits, nozzle-type suppliers or collection chambers of types known to those skilled in the art and, therefore, not they will be mentioned in detail in the present description.

Similarly, the means 6 and 8 for feeding, respectively extracting, the gaseous phase of column 1 generally comprise gas inlets and outlets of types known to those skilled in the art and, therefore, will not be mentioned. with detail in the present description. In the examples of Figures 1, 3 and 5, the liquid phase is fed by the medium 5 to an upper end of the column 1, and is extracted by the medium 7 from a lower end thereof. Therefore, the liquid phase will flow through column 1 in a manner known per se, that is, in a substantially axial direction. The gas phase is fed by the medium 6 to the lower end of the column 1 and is extracted from the upper end thereof by means 8. The liquid phase and the gas phase could, however, be fed to and removed from intermediate locations of the column 1, and this is usually done in traditional fill type columns.

In other words, the means for feeding, respectively extracting, the liquid phase and / or the gas phase can be provided anywhere along the liner 2, in order to maintain the constant operational conditions within the column or to improve the transfer of mass between the phases. According to the present invention, at least one reservoir 3 is conveniently provided with a gas permeable surface for the passage of the gas phase through the filler 4, which is larger than its cross section. For this purpose, the reservoir 3 is given a smaller cross section than the cross section of the liner 2, and has opposite side walls 9 and 10 which are gas permeable. In addition, column 1 conveniently includes appropriate means, which will be described, adapted to cause the gas phase to flow through the reservoir 3 in a prevailing radial direction. In this way, it is caused that the gas phase flows through the column 1 - contrary to the constant teachings of the prior art - countercurrent to the liquid phase along the prevailing radial flow direction. The gas permeable surface of the side walls 9 and 10 is conveniently provided larger than the cross section of the tank 3.

According to the embodiment shown in Figure 1, the refillable column 1 of the present invention comprises an external liner 2 which is substantially cylindrical in shape, and at least one annular reservoir 3a-3e for containing the filling 4 which is mounted inside the liner 2 coaxially thereto and has opposed internal and external cylindrical gas-permeable walls, 9 and 10 respectively. A first clearance 1 1 is formed between an interior wall 2a of the liner and the exterior wall 10 of the tank, and a second clearance 12 is formed within the interior wall 9 of the tank. Conveniently, column 1 further comprises means 9a, 10a, 14, 15 for causing at least a larger portion of the gas phase to flow through at least one reservoir 3a-3e, of the first clear space 1 1 to the second free space 12 or vice versa. In the example of Figure 1, column 1 contains five annular deposits 3a-3e to contain the fill 4, which are superimposed and placed coaxially within the shell 2. These deposits are pierced by the liquid phase from the top in descending form of column 1 with a considerably axial direction, and by the gas phase from the bottom in ascending form with a considerably axial-radial direction, as indicated by arrows Fg. The number of deposits 3 within the liner 2 can vary to fit the size of column 1 and look for the range of the mass transfer. A number of deposits in a range of one to twenty should be considered adequate to satisfy most requirements. In order to promote mass transfer between the phases and ensure optimal operating conditions through the column 1, the tanks 3a-3e for containing the filling 4 can conveniently be provided in different lengths, for example, the deposit 3a being the longest which is placed upside down and the other deposits gradually decreasing in length until the deposit 3e placed up which would be the shortest. The reservoirs 3a-3e shown in Figure 1 are placed contiguously and each has a perforated bottom 13 which can be penetrated by both the liquid phase and the gas phase. Conveniently, the perforated bottom 13 of the deposits 3a-3e is of the proper size to divert the gas phase radially and / or to gather and redistribute the liquid phase between the reservoirs.

The presence of perforated funds 13 between deposits 3a-3e contiguously in succession produces a controlled increase of the predetermined entity in the pressure drop of the gas phase flowing through the reservoir, which allows at least part of that phase to be deviated radially, and that the liquid phase that flows out of a deposit is reunited and redistributed as an option in the next deposit.

By gathering and redistributing the liquid phase between the successive deposits 3a-3e, optimal conditions for the mass transfer between the phases can be ensured, using the entire area of the surface of the filling 4 and avoiding the formation of preferential flow paths where the liquid phase passes through the filling. The portion of the gas phase that has deviated radially out of a reservoir 3a-3d is reintroduced to the next reservoir 3a-3e, again in the radial flow direction. Preferably, the radial flow of the gas phase through the tanks 3a-3e is either centrifugal or centripetal type. Satisfactory results have been obtained in particular by using a centripetal and centrifugal flow alternately (or vice versa), as indicated by arrows Fg in Figure 1. That is, the gas phase passes radially through successive deposits 3a-3e in opposite directions. The tanks 3a-3e, or only some of them, can be placed within the column 1 at suitable distances from one another to define the respective cylindrical spaces between the successive tanks. These spaces can conveniently accommodate means (not shown) to collect and redistribute the liquid phase from one deposit to the next, which means are conventional and will not be mentioned in detail in the present description.

As an alternative to having a variety of deposits, column 1 according to the present invention could conveniently have a single deposit 3 divided into a variety of zones (indicated in Figure 1 with the same reference 3a-3e as the deposits), contiguously one on top of the other. This arrangement should be considered as a considerable equivalent to the arrangement of the deposit shown in Figure 1. According to this embodiment, perforated bottoms 1 3 are not provided and filling 4 within the deposit 3 forms a single contiguous body. According to a particularly convenient aspect of the present invention, the outer wall 10, or the inner wall 9, of at least one reservoir 3a-3e comprises a portion 10a, 9a respectively, which is impermeable to gas and is a predetermined length along an upper end thereof. In the example of Figure 1, both the outer wall 10 and the inner wall 9 of each tank 3a-3c conveniently comprise the gas impermeable portion 10a and 9a, respectively. Instead of the tanks 3a-3c, where the column 1 comprises a single tank 3 divided into a variety of zones 3a-3c as described above, the gas impervious portions 9a and 10a of predetermined length of the inner wall 9 and / or the outer wall 10, respectively, of the reservoir 3 could be defined along an upper end of each zone.

By providing a gas impermeable upper portion in at least one of, preferably both, side walls of the tanks or zones 3a-3c, a larger portion of the gas phase stream flowing from bottom to top through the Filling 4 can be radially deviated in a simple and effective manner, which allows the gas phase to flow through column 1 in a prevailing radial direction. In fact, the non-perforated portion of the side walls 9 and / or 10 produces a controlled increase (of predetermined entity) in the pressure drop of the gas phase which conveniently prevents axial flow through the filler 4, so that the current of the gas phase deviates radially. The proportion of the gas phase passing radially, axially respectively, through the filling 4 depends on the length or extension of the gas impervious portions 9a and / or 10a, since the pressure drop to which it is subjected the gas phase could vary correspondingly to said portions. By increasing the length of the gas impervious portion, the axial flow resistance and, consequently, the radial flow component of the gas phase are increased. As shown in Figure 1, it is only a minor portion of the gas phase that passes through the filler 4 in a substantially axial flow, while the larger portion thereof follows substantially radial flow paths, resulting in a mixed flow is established, that is, axial-radial.

Where both side walls 9 and 10 of the reservoir (s) 3a-3e include gas impermeable portions 9a and 9b, the length of each portion may be differently convenient for the inner wall 9 and the outer wall 10, so as to increase or decrease the radial component of the flow of the gas phase. Satisfactory results have been obtained particularly with the gas impermeable portion 9a, 10a, being 5% to 30% of the length of the inner wall 9 and / or the external wall of the tank 3a-3e. It is preferable that the length of the gas impermeable portion be within a range of 10% to 25%. According to another particular convenient aspect of the present invention, column 1 includes gas impermeable means 14 and 1 5 to close the free spaces 1 1 and 12 placed in the first and second free spaces 1 1 and 12 respectively. According to the example of Figure 1, in at least one tank 3a-3e, these closing means conveniently comprise an annular baffle 14 which is impervious to gas and is positioned at an upper end of the first clear space 1 1, and a circular baffle 15 which is impermeable to gas and is placed at a lower end of the second free space 12. In this way, the gas phase is caused to pass from a reservoir 3a-3d to the next reservoir 3b-3e in a centripetal and centrifugal flow alternately in a prevailing radial direction, while preventing the phase of gas diversion in one or more tanks, which would adversely affect the total efficiency of the mass transfer that takes place between the phases . In fact, when it is originated that at least a larger portion of the gas phase flows radially through the filling 4, what matters is that the gas leaving a certain deposit is directed to the next deposit, in such a way , that can not flow out and cover other deposits in the column or even escape from the column. The gaseous phase where it will move alternately from a reservoir 3a-3d to the next 3b-3e in a mainly radial flow of centrifugal and centripetal type, the annular baffle 14 impermeable to gas will be placed at a lower end of the first free space 11, and the gas-impermeable circular baffle 15 will be positioned at an upper end of the second clearance 12. In the example of FIG. 1, where a considerably axial-radial flow of the gas phase passes through column 1, the deposits 3a -3e are left open at their upper ends, instead of being closed by means of a gas impermeable liner. This greatly facilitates the liquid phase passing axially therethrough and, in particular, the upper reservoir 3e, facilitates the feeding and distribution of this phase in the filling 4 contained therein. In Figure 1, the number 16 usually indicates a heat exchanger placed in the second free space 12 in the tank 3c, to subject the gas phase, which leaves the tank 3c with a radial flow and goes to the next 3d deposit, in an indirect heat exchange with a heating or cooling fluid, such as water. In particular, it is caused that the gas phase flows through the heat exchanger 16 on the side of the liner, with the heating or cooling fluid on the side of the column. More simply, the means for feeding and removing the heating or cooling fluid from the heat exchanger 16 have been omitted in Figure 1 for reasons known per se. Depending on the individual requirements, one or more heat exchangers 16 can be placed in the free space 12, which provide indirect heat exchange for at least some of the gaseous phases flowing between the successive tanks 3a-3e. By providing a heat exchanger 16 in column 1, the processes of purification, absorption, distillation and decomposition for which the column is projected can all be improved.

As mentioned above, all the features, except the gas permeable background 13, described in relation to the tanks 3a-3e also apply to the particular mode, (not shown), of the present invention wherein the column 1 it comprises a single tank 3 divided into a variety of zones 3a-3e. Figure 3 shows a modality of a column 1 for implementing the process according to the present invention, which differs from the example of Figure 1, mainly in that it causes the gas phase to flow through the filling 4 in a direction considerably radial, instead of axial-radial. In this Figure, the parts of column 1, which are structurally and functionally equivalent to those shown in Figure 1, bear the same reference numbers and will not be mentioned in detail in the present description. Conveniently, the gas phase is caused to flow in a substantially radial direction by closing the upper end of the tank (s) 3 equipped with the filler 4, placed inside the column 1. For this purpose, at least one tank 3 has a gas impermeable liner 17 mounted on its upper end. In the example of Figure 3, the tanks 3a and 3b each are provided with a cover 17, such that neither a minor portion of the gas phase will pass through the fill 4 in an axial flow direction . Due to the liner impermeable to gas 17, the gas phase is forced to flow radially through the filler 4, and it is prevented from leaving the tanks 3a-3b in an axial direction. In this case, the gas impermeable portion 9a, 10a respectively, of the internal and external side walls 9 and 10 of the tanks 3a-3b, in addition to diverting the flow of the gas phase in a radial direction, conveniently prevents the deposits 3a-3b deviate undesirably with at least a portion of said phase, which can infiltrate through any opening between the cover 17 and the filling 4, directly from the first free space to the second 1 1, 12 respectively , or vice versa, affecting the total efficiency of the mass transfer between the phases. It is preferable that the gas phase flows, as indicated by the arrows Fg in Figure 3, radially outwardly through the first tank 3a and radially inwardly through the second tank 3b. The radial direction of the gas phase can be selected to fit the construction of column 1, and can be either centripetal or centrifugal only, or centripetal and centrifugal (or vice versa). Similar to the example shown in Figure 1, the advantages that result from selecting a particular direction for the flow of the gas phase concern the manufacture of column 1, but they are of trivial importance for the efficiency of the transfer of gas. mass between the phases. In addition, a combined process could be provided with some of the reservoirs 3 that are traversed by the gas phase in a direction of substantially radial flow, and some others in axial-radial direction. In this case, not all tanks 3a-3b would be adjusted with a liner impervious to gas 17. The number of tanks 3a-3b shown in Figure 3 and their different lengths are merely illustrative, and may vary according to the needs as previously described in relation to Figure 1. It should be noted that the means 5 for feeding the liquid phase to the column 1 are placed between the cover 17 of the upper tank 3b and the filling 4. According to this embodiment, the liquid phase flowing out of the upper tank 3b is collected - by means which are not shown for reasons known per se - and redistributed to the lower tank 3a, for example, by means of a nozzle-type supplier 18, which is placed between a respective cover 17 and the filling 4. In convenient way, the reservoirs 3a and 3b are positioned adjacent to each other, with the cover 17 of the lower reservoir 3a forming the gas-impermeable bottom of the upper reservoir 3b. Therefore, a column of compact and simple construction is obtained. However, a variety of deposits 3 spaced apart from one another within column 1 could be provided instead. Although not shown in Figure 3, the free space 12 can conveniently accommodate one or more heat exchangers for an indirect heat exchange between the gas phase flowing from one tank to the other and a heating or cooling fluid. , as described in relation to Figure 1. According to another embodiment of the present invention shown in Figure 5, the column 1 includes at least one reservoir 3a-3c for containing the filling 4 and which is placed coaxially within the liner 2 and has opposite side walls 19 20, which are permeable to gas and preferably are flat.

There are the first and second free spaces 21 and 22, on opposite sides to each other defined between the inner wall 2a of the liner 2 and the side walls 19 and 20 of the tanks 3a-3c. Conveniently, appropriate means (19a, 20a, 23) are provided to cause at least a larger portion of the gas phase to flow in the column 1 through at least one reservoir 3a-3c, of the first free space 21 to the second free space, or vice versa. In Figure 5, the parts of column 1, which are equivalent in structural form and in functional form to those shown in the previous Figures, are indicated by the same reference numbers and will not be mentioned in detail herein. description. According to this embodiment of the present invention, it is caused that the liquid phase flows through the filler 4 from top to bottom in a considerably axial direction, while the gas phase flows conveniently through the filler 4 in a substantially transverse direction of down up. In other words, the gas phase moves from one side of the tank 3a-3c to the other in an essentially oblique flow where the horizontal component prevails.

It is preferable, as shown in Figures 5 and 6, that the liner 2 be of substantially cylindrical shape, and the transverse shape of the free spaces 21 and 22 be a circular sector. In this way, the available space within the column 1 can be used better and spacious 3a-3c tanks can be provided to contain the filling 4, as well as free spaces 21 and 22 wide enough to allow the gas phase to flow through without a undue frictional drag. In a manner similar to the previous examples, again at least one of the side walls 19 and 20, both preferably, of the reservoir 3a-3c comprises a gas impermeable portion 19a, 20a respectively, of a predetermined length at an upper end of the same, which is effective to divert the flow of the gas phase horizontally. In addition, column 1 conveniently includes gas impermeable means 23 for closing the free spaces 21 and 22, placed in the first and second free spaces 21 and 22. For this purpose, the closing means comprise a gas-impermeable deflector 23 placed at an upper end of the first clearance 21, and a gas-impermeable baffle 23 placed at a lower end of the second clearance 22. In an alternative embodiment, not shown, the gas-impermeable baffles 23 are placed at a lower end first free space 21 and at an upper end of the second free space 22, respectively.

In the example of Figure 5, these deflectors 23 have a circular sector shape. The baffles 23 are conveniently effective to induce a transverse flow of the gas phase through the filler 4 of the first free space 21 to the second 22 and / or vice versa, while preventing the phase of undesirable gas diversion in the tanks 3a-3c. As regards the length of the gas impermeable portion 19a and 20a of the side walls 19 and 20, as well as the number, placement and length of the tanks 3a-3c within the column 1, the same apply features and advantages as set forth above in relation to the previous Figures. Just as an example, it is observed that in column 1 of the Figure 5 three catalytic deposits 3a-3c are placed in coaxial form, equipped with the filling 4, superimposed and contiguously one from another, wherein the upper tank 3c is longer than the tanks 3a-3b below. A perforated bottom 13 is provided in each reservoir 3a-3c to pass the liquid phase and a minor portion of the gas phase between the successive reservoirs. In addition, the tanks 3a-3c are open at the upper end. As a result, in the example of Figure 5, the gas phase is conveniently allowed to flow through the tanks 3a-3c in a mixed axial and transverse direction.

Alternatively, in a manner not shown in the drawings, the reservoirs 3a and 3c can be fitted with respective gas-impermeable liners at their upper ends, so that a true transverse flow of the gas phase through the filling can be provided. 4. Also within the scope of the present invention is a column 1 comprising some of the tanks through which the gas phase flows in a substantially transverse direction and others of the tanks through which it flows in a mixed axial and transverse direction. Deposits 3a-3c can conveniently be placed in a mutually spaced relationship within column 1. Also, suitable means may be provided between the successive reservoirs 3a-3c to collect and redistribute the liquid phase. In the example of Figure 5, these means comprise the perforated bottoms 13 which are provided at the lower ends of the tanks 3a-3c, which are sized to divert the flow of the gas phase transversely and / or to collect and redistribute the liquid phase that flows between the successive deposits. Alternatively, column 1 could conveniently comprise, instead of deposits 3a-3c, a single reservoir 3 divided into a variety of contiguous superimposed zones, not shown, which can be compared respectively with the reservoirs 3a-3c described previously and has the same characteristics and advantages. Of course, non-perforated bottoms 13 or gas impervious liners will be provided between said contiguous zones. A column 1 will also be placed to incorporate a variety of deposits 3a-3c, with at least one of the deposits divided into the variety of areas mentioned above. According to a particularly not shown but convenient embodiment of the present invention, a substantially radial or transverse flow of the gas phase can be provided through a column 1 of the type described in relation to Figure 3 or 5, by replacing the gas-impermeable liners per gas-permeable perforated liners, and conveniently exploiting the hydrostatic liquid head that is formed in said perforated liners to stop the axial flow of the gas phase through the reservoir. In other words, the liquid phase - which originates from top to bottom through column 1 - once the deposit is left, gathers in the perforated lining of the next deposit and before it is redistributed and passes through from this next deposit, it forms a horizontal liquid layer that can not be penetrated by the gas phase, so that the gas phase is forced to flow in the transverse or radial direction. The present invention is not limited by a specific type of filler 4, and any type of filler can be used within column 1, including textured or random types. Conveniently, fillers 4 of different types can be interposed between the reservoirs or between the zones of a reservoir, so that the flow range of the gas phase and the mass transfer between the phases flowing through column 1, they can be controlled or 'modified. The filler 4 can be made of inert material with respect to the liquid and gaseous phases that flow or can be a suitable catalyst, or be mixtures of the same. In case a catalyst is used in column 1, then chemical reactions can be carried out in addition to the mass transfer between the phases. According to the process of the present invention and in relation to the modalities described in Figures 1-6, to effect a mass transfer between a liquid phase and a gas phase within a refillable column 1 comprising an external liner 2 which accommodates at least one reservoir 3 for containing the filling 4 where said phases flow in countercurrent, the gas phase is conveniently fed in at least one reservoir 3 through a gas permeable surface (9)., 10, 19, 20) thereof, which is larger than the cross section of the deposit. It is preferable that this process for effecting a mass transfer between a liquid phase and a gas phase is carried out within a refillable column 1 comprising an outer liner 2 which accommodates at least one reservoir 3 to contain the filling 4 and having a cross section smaller than the cross section of the liner 2, and comprising the steps of feeding (means 5 and 6) the liquid and gaseous phases in the refillable column 1, causing the liquid phase to flow through the minus a reservoir 3 in a substantially axial direction, causing the gas phase to flow through at least one reservoir 3 in a prevailing radial direction (means 9a, 10a, 14, 14, 19a, 20a, 23) and extracting (means 7 and 8) the liquid and gaseous phases of the refillable column 1. As described above, a reduction in the pressure drop of the gas phase flowing through the backfill 4 can be provided by the current process, where the optimum flow rates and speeds can be reached for that phase (and for the liquid phase) effectively to increase the mass transfer between a liquid phase and a gas phase. In addition to this, it has been unexpectedly discovered that by causing the gas phase to flow mainly radially through the filler 4, a higher efficiency for mass transfer can be achieved, because there is a positive influence on the force promoter, which is responsible for said transfer. The operating conditions (such as pressure and temperature) of the current process can be changed within wide limits to adjust the types of fluids that will be processed and carry out any chemical operation.

The present invention can also be conveniently applied in columns having deposits containing both plates and fillers. The column shown in Figures 1, 3 and 5 may be new, or alternatively may be - according to a convenient and preferred aspect of the present invention - a pre-existing column of the filler or plate type modified to carry out the mass transfer between a liquid phase and a gas phase. Conveniently, the method for modifying said column comprises the step of providing therein at least one reservoir 3 for containing the filler 4 which has a gas permeable surface, to pass the gas phase, which is larger than its cross section. In particular, the modification method according to the present invention is characterized in that it comprises the steps of providing, within the pre-existing column, at least one reservoir 3 for containing the filling 4 which has a smaller cross-section than the cross section of the column and has opposite side walls permeable to gas 9, 10, 19, 20 and to provide, within the column, means 9a, 10a, 14, 15, 19a, 20a, 23 that cause the gas phase to flow through at least one deposit in a prevailing radial direction. To obtain a column 1 of the same type as described in relation to Figure 1 or 3, this method of modification conveniently comprises the steps of providing at least one annular reservoir 3 for containing the filling 4 placed coaxially within the column 1, whose tank 3 has opposite gas-permeable internal and external cylindrical walls, 9 and 10, which define a first free space 1 1 between an internal wall 2a of the column 1 and the external wall 10 of the tank 3, and which define a second free space 12 formed inwardly of the inner wall 9 of the reservoir 3, and which provides means 9a, 10, 14 and 15 to cause at least a larger portion of the gas phase to flow through at least one reservoir 3 , from the first free space 1 1 to the second free space 12, or vice versa. To obtain a column 1 of the type described in relation to Figure 5, the method conveniently comprises the steps of providing at least one reservoir 3 for containing the filling 4 placed coaxially within the column 1, whose reservoir 3 has side walls 19 and 20 opposed, preferably flat, gas permeable defining a first and second free spaces 21 and 22 placed on opposite sides of one another between an inner wall 2a of the column 1 and the side walls 19-20 of the tank 3 and providing means 19a, 20a, 23 which cause at least a larger portion of the gas phase to flow through at least one reservoir of the first free space 21 to the second free space 22 or vice versa. Due to the current method to modify preexisting columns to effect a mass transfer between a liquid phase and a gas phase, it is conveniently possible to achieve a significant increase in the capacity of the column, and a reduction in energy consumption, since once that the column has been modernized can operate more effectively at larger flow ranges of the liquid and gaseous phases. In addition, according to other embodiments of the modification method according to the present invention, additional methods or features may be provided, as defined in pending Claims 32-37 and 39-44 attached hereto. Other structural and processing advantages that come from the current modification method can be deduced from the previous description of Figures 1-6. It can be seen that, by implementing the modification method according to the present invention, at least some of the construction elements that are originally included in the column have to be removed in a preliminary step, it being possible to reuse said elements, for example, provide funds or covers for new deposits that contain fill. From the above description clearly emerge the numerous advantages that are achieved with the present invention; in particular, a process is obtained to effect a highly efficient mass transfer between a liquid phase and a gaseous phase, in a simple and reliable manner, at low investment and operating costs and with low energy consumption.

Claims (44)

1. R E I V I N D I C A I N N E S Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1 . A process for effecting a mass transfer between a liquid phase and a gas phase within a refillable column which comprises an external liner that accommodates at least one reservoir containing filler wherein said phases originate to flow in countercurrent relation, characterized also because it comprises the step of feeding said gas phase to at least one reservoir through a surface of the gas permeable reservoir which is larger than the cross section of the reservoir.
2. 2. A process for effecting a mass transfer between a liquid phase and a gaseous phase within a refillable column which comprises an outer liner that accommodates at least one reservoir containing filler whose cross section is smaller than the cross section of said liner , said process comprises the steps of: - Feeding said liquid phase and gaseous phase to said refillable column; - causing the liquid phase to flow through at least one reservoir in a substantially axial direction; - causing the gas phase to flow through at least one reservoir in a prevailing radial direction; - Extract said liquid phase and gas phase from said refillable column.
3. 3. A process as described in Claim 2, further characterized in that said gas phase is caused to flow through at least one reservoir in a substantially radial, axial-radial or transverse direction.
4. 4. A process as described in Claim 2, further characterized in that said gaseous phase is caused to flow in at least one reservoir through a variety of contiguous overlapping zones.
5. 5. A process as described in Claim 2, further characterized in that said liquid phase and gas phase originate in a direction prevailingly axially and radially prevalent, through a variety of superimposed deposits containing filler.
6. 6. A process as described in Claim 5, further characterized in that it comprises the step of: Collect and redistribute said liquid phase between the successive deposits.
7. 7. A process as described in Claims 4 and 5, further characterized in that it comprises the step of: - Subjecting at least a portion of said gas phase to an indirect heat exchange while said gas phase flows from one zone to the next , from one deposit to the next respectively.
8. 8. A refillable column for a mass transfer between an liquid phase and a gas phase comprising: - An external liner (2); - At least one tank (3) for containing the filling (4) that extends inside said lining (2), at least one tank (3) which is penetrated through said phases in a countercurrent relation; - respective means (5,6) for feeding said liquid phase and said gaseous phase of said column; - respective means (7,8) for extracting said liquid phase and said gas phase from said column; Further characterized in that at least one tank (3) is provided with a gas permeable surface, to pass the gas phase, which is larger than its cross section.
9. 9. A column as described in Claim 8, further characterized in that at least one reservoir (3) has a smaller cross section than the cross section of the liner (2) and has opposite side walls (9, 10, 1). 9.29) which are permeable to gas, and further comprises means (9a, 10a, 14, 15, 19a, 20a, 23) to cause the gas phase to flow through at least one reservoir (3) in a radial flow mainly.
10. 10. A column as described in Claim 8, further characterized in that it comprises: - An external liner (2), of substantially cylindrical shape; - At least one annular reservoir (3a-3e) for containing the filling (4) which is placed coaxially inside said liner (2) and includes opposed internal and external cylindrical walls (9, 10) respectively permeable to gas , at least one reservoir (3) which is penetrated through said liquid phase in a substantially axial direction; - A first free space (11) defined between an internal wall (2a) of the liner (2) and said external wall (10) of the tank (3a-3e); - A second free space (12) defined inwardly of said internal wall (9) of the tank (3a-3e); - respective means (5, 6) for feeding said liquid phase and said gaseous phase to said column; - Means (9a, 10a, 14, 15) to cause at least a larger portion of said gas phase to flow through at least one reservoir (3a-3e), from said first free space (11) to said second free space (12), or vice versa; - respective means (7,8) for extracting said liquid phase and said gas phase from said column. eleven .
11. A column as described in Claim 10, further characterized in that at least one tank (3) is divided into a variety of contiguously superposed zones (3a-3e), said means (9a, 1 0a, 14). , 15) to cause at least a greater portion of said gas phase to flow through the reservoir (3) of said first free space (11) to said second free space (12) or vice versa, being placed at each of said zones (3a-3e).
12. 12. A column as described in the Claims 10 and 11, further characterized in that said external wall (10) of the tank and / or said internal wall (9) of the tank comprises, at an upper end of at least one tank (3a-3e), at an upper end of the tank. each zone (3a-3e) respectively, a gas impervious portion (9a, 10a) of predetermined length, the length of said gas impermeable portion (9a, 10a) which is of a different length of preference for the outer walls (1 0) and internal (9) of the deposit.
13. 13. A column as described in Claim 12, further characterized in that said gas impermeable portion (9a, 10a) is stretched over 5% to 30% of the length of said outer (10) and / or internal (9) walls. of the reservoir (3a-3e), respectively to the length of said zone (3a-3e).
14. 14. A column as described in Claims 10 to 13, further characterized in that at least one reservoir (3a-3e), each of said zones (3a-3e) comprises, respectively, gas-tight sealing means. (14, 15) for said free spaces (11, 12) placed to said first and said second free spaces (11, 12).
15. 15. A column as described in Claim 14, further characterized in that said closing means (14, 15) comprise an annular deflector (14) impermeable to gas placed at a lower end of said first free space (1 1), respectively to said zones (3a-3e), and a circular baffle (15) impermeable to gas placed at an upper end of said second free space (12), respectively to said zones (3a-3e), or an annular deflector (14) gas impermeable placed at an upper end of said first free space (11), respectively said zones (3a-3e) and a circular baffle (15) impermeable to gas placed at a lower end of said second free space (12) , respectively to said zones (3a-3e).
16. 16. A column as described in Claim 10, further characterized in that it comprises a variety of annular deposits (3a-3e) for containing the filler (4) which are superimposed and placed coaxially within said liner (2), said deposits (3a-3e) that are preferably contiguous with one another and / or different in length.
17. 17. A column as described in Claims 1 and 16, further characterized in that it comprises at least one heat exchanger (16) placed in said second clearance (12) to provide an indirect heat exchange with at least part of the gaseous phase flowing from one zone (3a-3d) to the next (3a-3e) of at least one tank (3), from one tank (3a-3d) to the next (3a-3e) respectively.
18. 18. A column as described in Claim 8, further characterized in that it comprises: - An external liner (2) of substantially cylindrical shape preferably; - At least one tank (3a-3c) to contain the filling (4), placed inside said liner (2) in a coaxial form thereof and provided with opposite lateral walls (19,20), preferably flat, which are permeable to gas, at least one reservoir (3a-3c) that is penetrated through said liquid phase in a direction of substantially axial flow; - First and second free spaces (21, 22), placed on opposite sides of one another and defined between an internal wall (2a) of said liner (2) and said side walls (19,20) of the tank (3a, 3c) , said free spaces having a circular sector shape preferably in cross section; - respective means (5, 6) for feeding said liquid phase and said gaseous phase to said column; - Means (19a, 20a, 23) to cause at least a greater portion of said gas phase to flow through at least one reservoir (3a-3c), from said first free space (21) to said second free space (22) or vice versa; - respective means (7, 8) for extracting said liquid phase and said gaseous phase from said column;
19. 19. A column as described in Claims 10 and 18, further characterized in that at least one reservoir (3a-3e) is open at its upper end.
20. 20. A column as described in Claims 10 and 18, further characterized in that at least one reservoir (3a-3e) comprises a gas impervious cover (17) at its upper end. twenty-one .
21. A column as described in Claim 18, further characterized in that at least one tank (3) is divided into a variety of zones (3a-3c) superimposed in contiguous manner, said means (1 9a, 20a, 23) to cause at least a larger portion of said gas phase to flow through the reservoir (3) of said first free space (21) to said second free space (22), or vice versa, provided in each of said zones (3a) -3c).
22. 22. A column as described in the Claims 18 and 21, further characterized in that at least one of the side walls (19, 20) of the tank comprises, at an upper end of at least one tank (3a-3c), at the upper end of each zone (3a- 3c) respectively, a portion (19a, 20a) impervious to gas of predetermined length, the length of said portion (19a, 20a) being impermeable to the gas preferably of a different length for each side wall (19, 20) of the reservoir.
23. 23. A column as described in Claim 22, further characterized in that said gas-impermeable portion (19a, 20a) is stretched over the 5% to 30% length of said side walls of the tank (3a, 3c), of the length of said zone (3a-3c) respectively.
24. 24. A column as described in any of Claims 18 to 23, further characterized in that at least one reservoir (3a-3c), respectively to each of the zones (3a-3c) comprises closing means ( 23) gas impermeable for said free spaces placed in said first and said second free spaces (21, 22).
25. 25. A column as described in claim 24, further characterized in that said closing means comprise a baffle (23) impermeable to gas placed at a lower end of said first free space (21), respectively to said zones (3a-3c ), and a gas-impermeable baffle (23) placed at an upper end of said second clearance (22), respectively to said zones (3a-3c), or a gas-impermeable baffle (23) positioned at an upper end of said first free space (21) respectively to said zones (3a-3c), and a baffle (23) impermeable to gas placed at a lower end of said second free space (22), respectively to said zones (3a-3c).
26. 26. A column as described in Claim 18, further characterized in that it comprises a variety of reservoirs (3a-3c) to contain the filling (4) which are superposed and placed coaxially within said liner (2), said deposits (3a-3c) that are contiguous preferably one with another and / or different in length. >
27. 27. A column as described in Claims 1 6 and 26, further characterized in that said tanks (3a-3c) have a perforated bottom (1 3).
28. 28. A column as described in Claim 27, further characterized in that said perforated bottom (13) is of adequate size to deflect the gas phase in a radial direction, in a transverse direction respectively, and / or to collect and redistribute the phase liquid between the successive deposits (3a-3c).
29. 29. A method for modifying a column to effect a mass transfer between an liquid phase and a gas phase, being either of the filling or plate type, whose method is further characterized in that it comprises the step of: - Providing, within said column, at least one reservoir (3) for containing a filling (4) and having a gas permeable surface, for the passage of the gas phase, which is larger than its cross section.
30. 30. A method as described in Claim 29, further characterized in that it comprises the steps of: - Providing, within said column, at least one reservoir (3) for containing the filler (4) which has a further cross section small that the cross section of the column and has opposite lateral walls (9, 10, 19, 20) permeable to gas; - Provide, within said column, means (9a, 10a, 14, 15, 19a, 20a, 23) to cause said gaseous phase to flow through at least one reservoir (3) in a prevailing radial direction.
31. 31 A method as described in Claim 29, further characterized in that it comprises the steps of: - Providing at least one annular reservoir (3a-3e) for containing the filling (4) placed coaxially inside said column (2) ), said tank having gas-permeable internal and external cylindrical walls (9, 10) defining a first free space (11) between an internal wall (2a) of the column and said external wall (10) of the tank ( 3a-3e), and defining a second free space (12) formed inwardly of said internal wall (9) of the tank (3a-3c); - Providing means (9a, 10a, 14, 15) to cause at least a larger portion of said gas phase to flow through at least one reservoir (3a-3e) of said first free space (11) to said second free space (12), or vice versa.
32. 32. A method as described in Claim 31, further characterized in that at least one reservoir (3) is divided into a variety of zones (3a-3e) superimposed in contiguous manner, said means (9a, 10a, 14, 15). ) to cause at least a larger portion of said gas phase to flow through the reservoir of said first free space (11) to said second free space (12), provided to each of said zones (3a-3e).
33. 33. A method as described in claims 31 and 32, further characterized in that said external wall (10) of the tank and / or said internal wall (9) of the tank comprises, at an upper end of at least one tank (3a) -3e) at the upper end of each zone (3a-3e) respectively, a gas impervious portion (9a, 10a) of predetermined length, the length of said gas-impermeable portion (9a, 10a) being preferably of a length different for the external (10) and internal (9) walls of the tank.
34. 34. A method as described in any of the claims 31 to 33, further characterized in that it comprises the step of: - providing sealing means (14, 1 5) impervious to gas for said free spaces (11, 12 ), placed at said first and said second free spaces (1 1, 12) of at least one tank (3a-3e), respectively to each of said zones (3a-3e).
35. 35. A method as described in Claim 34, further characterized in that it comprises the steps of: - Providing an annular baffle (14) impermeable to gas either at a lower end or at an upper end of said first free space (1 1) respectively, for said zones (3a-3e); - Providing a circular baffle (15) impervious to gas at either an upper or lower end of said second free space (12) respectively, to said zones (3a-3e).
36. 36. A method as described in Claim 31, further characterized in that it comprises the step of: - Providing a variety of annular deposits (3a-3e) to contain the filling (4), superimposed and placed coaxially within said column .
37. 37. A method as described in Claim 32 or 36, further characterized in that it comprises the step of: - Providing at least one heat exchanger (16) in said second clearance (12) to exchange heat indirectly with at least part of the gaseous phase flowing from one zone (3a-3d) to the next (3b-3e) of at least one reservoir, or from one reservoir (3a-3d) to the other (3b-3e).
38. 38. A method as described in Claim 29, further characterized in that it comprises the steps of: - Providing at least one reservoir (3a-3c) for containing the filling (4) placed coaxially within said column and provided with side walls (1, 9, 20) opposite, preferably flat, gas permeable defining the first and second free spaces (21, 22) placed opposite each other between an internal wall (2a) of said column and said side walls (19, 20) of the deposit; - Provide means (19a, 20a, 23) to cause at least a larger portion of said gas phase to flow through at least one reservoir (3a-3c), said first free space (21) to said second space free (22), or vice versa.
39. 39. A method as described in Claim 38, further characterized in that at least one reservoir is divided into a variety of zones (3a-3c) superimposed in contiguous manner, said means (19a, 20a, 23) to cause that for at least a larger portion of said gas phase flows through the reservoir of said first free space (21) to said second free space (22) provided in each of said zones (3a-3c).
40. 40. A method as described in the Claims 38 and 39, further characterized in that at least one of said side walls (19, 20) of the tank comprises, at an upper end of at least one tank (3a-3c), at the upper end of each zone (3a- 3c) respectively, a portion (19a, 20a) impervious to gas of a predetermined length.
41. 41 A method as described in any of Claims 38 to 40, further characterized in that it comprises the step of: - Providing sealing means (23) gas impermeable for said free spaces (21, 22), placed at said first and said second free spaces (21, 22) of at least one store (3a-3c) respectively to each of said zones (3a-3c).
42. 42. A method as described in Claim 41, further characterized in that it comprises the steps of: - Providing a baffle (23) impervious to gas placed in either a lower end or an upper end of said first free space (11) respectively to said zones (3a-3c); - Providing a baffle (23) impermeable to gas placed either at a lower end or an upper end of said second clearance (22) respectively to said zones (3a-3c).
43. 43. A method as described in claims 31 and 38, further characterized in that at least one reservoir (3a-3e) comprises a cover (17) impervious to gas placed at the upper end thereof.
44. 44. A method as described in Claim 38, further characterized in that it comprises the step of: - Providing a variety of reservoirs (3a-3c) to contain the filling (4), superimposed and placed coaxially within said column. SUMMARY A process for effecting mass transfer between a liquid phase and a gas phase in a refillable column, comprising an outer shell which accommodates at least one reservoir containing a filler, through which the phases to flow originate. in a countercurrent relation, which conveniently comprises the feed passage of the gas phase to the at least one reservoir through a gas permeable surface thereof, which is larger than the transverse reservoir, preferably in a predominantly radial flow direction.