MX2010012173A - Use of adsorbents for the purification of dry cleaning solvents. - Google Patents

Abstract

The present invention refers to the use of an adsorbent comprising particles comprising an amorphous phase and a crystalline phase for the purification of dry cleaning solvents. The present invention furthermore relates to a filter unit containing such an adsorbent. It also refers to a dry cleaner containing a filter according to the invention. Additionally, the present invention refers to a process for dry cleaning textiles, wherein an adsorbent according to the invention is used.

Description

-? - USE OF ADSORBENTS FOR PURIFICATION OF SOLVENTS FOR CLEANING IN DRY The present invention relates to the use of an adsorbent comprising particles which in turn comprise an amorphous phase and a crystalline phase for the purification of solvents for dry cleaning. The present invention furthermore relates to a filter unit containing such an adsorbent It also relates to a dry cleaning / cleaning machine containing a filter unit according to the invention. process for dry cleaning of textiles, wherein an adsorbent is used according to the invention.

During the last 75 years, the dry cleaning of clothes and fabrics has become very important in the commercial and non-commercial sector. For this reason, various machines for dry cleaning have been developed, and are commercially available. Usually, the dry cleaning machines are equipped with a unit for the recovery and cleaning of the solvent for dry cleaning, during or after the washing process. The design of construction of the machines depends mainly on the solvent for dry cleaning and the solvent recovery unit for dry cleaning / cleaning with dry solvent that will be used.

Until now, a variety of solvents, including gasoline and kerosene, have been used in the dry cleaning process. At the beginning of the 20th century, carbon tetrachloride was widely used as a solvent for dry cleaning. However, it became evident that exposure to carbon tetrachloride has severe adverse effects on health, and it was found that tetrachlorethylene and trichlorethylene were more convenient.

Additional improvements were achieved by using perchlorethylene (perc), which is more stable, non-flammable, has excellent cleaning power, and is harmless to most of the pregnates of I wear. Other solvents that are currently used in the dry cleaning industry are hydrocarbon solvents such as; DF-2000 (DF-2000 ™ is a commercially pure synthetic aliphatic hydrocarbon, Alkanes G11 -15-ISO from Exxon Chemical) or EcoSolv (Ecosolv, also known as HC-DCF, is a C10-C13 isoparaffin of aliphatic hydrocarbons from Chevron Phillips). DF-2000 is a synthetic aliphatic hydrocarbon that has a flash point of 65 ° C, which allows safe handling of the solvent. Perc has a flash point of 45 ° C.

In order to remove stains from a variety of fabrics, the dry cleaning process for the most part requires the use of detergents and, sometimes, a small amount of water. Detergents help dissolve the hydrophilic dirt and prevent dirt from re-depositing on the garments. Depending on the design of the machine, an anionic or cationic detergent is used. An average dry cleaner uses around 230-270 liters of fluid.

The machines shake clothes similarly to a standard water washer to remove dirt, oil and nails. After the washing process, the dry cleaning solvent has to be purified to be used again. j Solvents for dry cleaning can be purified, for example, by using distillation processes. Approximately 95% of dry cleaning machines in the US are equipped with a stationary unit and a cooler to purify the solvent for dry cleaning after a certain amount of laundry has been cleaned. However, the distillation process is expensive and there is a potential risk of accidents when operating machines with solvents at high temperatures. Another disadvantage that results from the distillation purification of low-boiling solvents for dry cleaning is bacterial contamination. In the solvents of hydrocarbons and silicones, the distillation does not prevent or reduce the bacterial contamination of the solvent. Therefore, dry cleaning machines with stationary units often use additional processes to further improve the quality of the solvent for dry cleaning.

In addition to the stationary unit, many dry cleaning machines comprise separate "cartridge filters" or "carbon tower filters" filled with activated carbon, which can optionally be used to purify the solvent for dry cleaning when a fade is detected of colored clothes. Figure 1 shows a simplified diagram of a dry cleaning process that uses perc as the solvent for dry cleaning. The purification of the solvent for dry cleaning is carried out by using a stationary unit in combination with a carbon adsorbent and a filter for insoluble particles.

In some machines for dry cleaning, the stationary unit is replaced by filter units containing adsorbents. In a typical dry cleaning process, the dry cleaning solvent used is removed from the washing chamber and passed through several filtration stages before being returned to the washing chamber. The first stage can be a vessel trap that prevents small objects, such as lint, rivets, buttons and coins, from entering the solvent pump.

After this, the solvent passes through a filter that removes the lint and insoluble suspended dirt from the solvent for dry cleaning. Many machines use "rotating disc filters" in which the filter residue is removed from the filter surface by centrifugal action, while the filter is counter-washed with solvent for dry cleaning. ! After the lint filter, the solvent passes through an absorbent cartridge filter. This filter is made from activated clays and charcoal, and removes insoluble fine dirt and non-volatile residues, along with dyes, from the solvent for dry cleaning.

Finally, the solvent passes through a polishing filter that removes any dirt not previously removed. The clean solvent is then returned to the solvent tank in operation.

Filter cartridges are described in US 3,730,347, where filtration is achieved with a paper towel or filter element, while dissolved substances are usually removed by passing the contaminated solvent through a bed of a granular adsorbent, such as activated charcoal. Conventionally, the two elements are combined in a filter and solvent conditioning cartouche, through which the solvent passes first through an external tubular unit of accordion folded filter paper, and then flows through a concentric carbon tubular bed activated plant and towards a central perforated outlet tube. The solvent may be a halogenated aliphatic hydrocarbon such as perchlorethylene or 1,1,2-trichloro-1,2,2-trifluoroethane or a hydrocarbon of the Stoddard type of solvent.

Disk filtration is an alternative to the use of cartridge filters. It can also be used in combination with cartridge filters. The rotating disc system is composed; of a rigid sieve in the form of a tubular can. Inside the can, several discs with cloth filter (usually nylon) are lined up in a row. The contaminated solvent passes through the discs that may contain a filter medium such as carbon or diatomaceous earth.

In some processes, the solvent for dry cleaning passes through a mass or bed of activated carbon that adsorbs the contaminants. There are, however, several important detours that result from the use of activated carbon as an adsorbent to remove dissolved contaminants from solvents for dry cleaning. First, activated carbon tends to absorb solvent for dry cleaning, detergents and other auxiliaries added to solvents for dry cleaning. And, when the activated carbon becomes wet with water residues, it tends to clog the filters, thus avoiding the filtration of the solvent during the dry cleaning process.

US 4, 277, 336 and 3, 658, 459 disclose filters containing carbon and clay adsorbent materials. The useful life of such filters is limited by the capacity of the clay adsorbent in the filter. The clay adsorbent has a finite capacity to absorb contaminants and, once that capacity is covered, the filter must be replaced with a new filter.

WO 03/093563 relates to a filtering device for removing contaminants from the solvents used, wherein the filtering device is operatively connected to the reservoir and / or container, wherein the fabric article comes into contact with the solvent for dry cleaning. The adsorbent materials to be used in the filtration device are activated carbons which can be combined with additional adsorbent materials selected from the group consisting of a polar agent, a non-polar agent, a charged agent and the mixtures of the I same. ! US 3, 658, 459 discloses the use of attapulgite, packaged in a solvent-permeable container. The container, for example, can be a bag made from fibrous cellulose or synthetic material, or it can be a fine-mesh metal container. The container can be equipped with suitable means for handling the bag such as, for example, an extraction cord connected for the removal of the bag out of the solvent cleaning tank. During the dry cleaning process, the solvent dissolves soluble components such as grease, stains, wax, fats, oils and the like, from soiled garments and fabrics. The contaminated solvent passes through the solvent-permeable bag and comes in contact with the attapulgite, which removes contaminants. | The dry cleaning machines, which were used with respect to the present invention, can be obtained from Kelleher, USA (compare the experimental part). Kelleher hydrocarbon machines are equipped with a filter unit containing adsorbents for the recovery and purification of solvents for dry cleaning. As a solvent for dry cleaning, for example, DF 2000 or perc can be used. Dry cleaning machines are designed for the use, for example, of commercially available Tonsil® adsorbents, for example, "Tonsil® 414 FF", which can be obtained from Sued-Chemie AG, Germany. Tonsil® 414 FF filter dust is produced by using bentonite as the starting material. Tonsil® 414 FF has very good properties with respect to the adsorption of non-volatile residues, lint, dyes, grease, dirt, soaps and detergent residues. For use in the cleaning process ß? dry, Tonsil® 414 FF is mixed with 50% by weight of diatomaceous earth (also known as DE). i The diatomaceous earth consists of 86% silica, 5% sodium, 3% magnesium and 2% iron.

The pre-coating of the nylon rotating disc filter with adsorbents before the washing process is described in example 2. j The use of diatomaceous earth is necessary to improve the total performance of the filtration through the rotating nylon disc filters. However, since the diatomaceous earth represents an inert material, the cleaning capacity per kilogram combined is lower than when using a pure adsorbent.

In addition, it is not possible to use Tonsil® 414 FF in cartridge filters, since fine material leads to clogging of the filter. Accordingly, there is a need for an adsorbent which possesses the same or even better cleaning properties, for example the cleaning capacity, compared to Tonsil® 414 FF, but which does not have the drawbacks mentioned above. Such an adsorbent should preferably be suitable for application in pure form when rotating disk filters are used.

As mentioned above, some commercially available dry cleaning machines have a small separate side filter called "carbon tower" or "deco" filter. (abbreviation for bleach). These filters are usually filled with carbon granules and can be obtained, for example, from Kleen-Rite, EU. However, these filters are not as effective as Tonsil® with respect to the elimination of dyes. In addition, carbon granules saturate rather quickly and must be replaced very often. For example, Kleen-Rite recommends changing the carbon cartridge every 907,185 kilograms (2000 pounds) of clothing, depending on the degree of impurities in the fiber fabrics. In this way, it would be useful to replace the carbon granules of those separate filters with a more effective adsorbent. However, the filter cartridges can only be filled with granular material due to the pore size of the filter cartridge. Therefore, Tonsil® adsorbents in powder form are not particularly suitable because they can not be held well in the filter cartridge.

Therefore, an object of the present invention is to provide adsorbents having improved properties, such as improved cleaning ability and increased filtration properties, for the purification of solvents for dry cleaning. An additional objective is to provide filter units for the purification of solvents for dry cleaning without the need for additional stationary units. Due to the easy handling, cartridge filters are the filter system especially preferred. j The fundamental objectives for a first aspect of the present invention have been solved by the subject matter, as defined in the claims.

The well-known Tonsil® 414 FF adsorbent represents a layered silicate that does not have adequate filtration properties in pure form for use with nyjon disc filters. It has been unexpectedly found that adsorbents comprising particles, which in turn comprise an amorphous phase and a crystalline phase, have very good filtration properties and can be used directly in pure form with rotating disk filters, without the addition being necessary. of DE (see example 2 below). ' In the known dry cleaning processes, Tonsil® 414 FF is usually used in increments of 0.454-1.361 kilograms (1 -3 pounds) (with equal parts of DE) with nylon disc filters. This amount of Tonsil® 414 FF (with corresponding DE) is adequate to clean 158,757-226,796 kilograms (350-500 pounds) of laundry. It has been found that the adsorbents to be used in accordance with the present invention have a superior cleaning ability and do not have to be replaced as often as the Tonsil® adsorbents. In addition, less waste is produced in the washing process, since the adsorbent according to the invention provides superior performance. Figure 2 shows a simplified diagram for dry cleaning using perc as the solvent for dry cleaning and nylon spinning disc filters. When Tonsil® adsorbents are used, it is not necessary to distill the solvent for dry cleaning.

It has been found that the granular adsorbents to be used according to the invention have a very high cleaning capacity when purifying solvent for dry cleaning. For example, two divided cartridges (containing 4.536-6.804 kilograms (10-5 pounds) of granular adsorbent) can filter the solvent for dry cleaning of approximately 1, 814.37-2,267,962 kilograms (4000-5000 pounds) of processed clothing, which has been used in all kinds of colored clothing. Filter cartridges are useful because they can be replaced more easily than rotary disk filters. Figure 3 represents a simplified diagram for a dry cleaning process where the dry cleaning solvent is purified by using a granular adsorbent and a filter for insoluble particles.

In addition, it has unexpectedly been found that the Herios filter cartridges of granular adsorbents, in accordance with the invention, remove dyes from solvents for dry cleaning faster than a distillation process can. In comparison with the dry cleaning processes with a distillation stage, the filters and cartridges according to the invention also reduce the amount of energy required for the process,? Furthermore, it was found that the use of adsorbents comprising particles, which in turn comprise an amorphous phase and a crystalline phase, allows to reduce the bacterial contamination of the solvents for dry cleaning. j The present invention relates to the use of an adsorbent comprising particles which in turn comprise an amorphous phase and a crystalline phase for the purification of solvents for dry cleaning.

The term "dry cleaning solvent", as used herein, refers to any solvent suitable for use in a dry cleaning process. Preferably, the dry cleaning solvents to be used from the point of view of the present invention are hydrocarbon solvents, halogenated hydrocarbon solvents (chlorinated or fluorinated), silicone solvents or mixtures thereof. The silicone solvents are polysiloxanes and can be, for example, dialkylsiloxanes, alkylarylsiloxanes, diarylsiloxanes, alkoxylated polydimethylsiloxanes, or fluoroalkylsiloxanes. A preferred silicone solvent is decamethylcyclopentasiloxane. Even more preferred, the dry cleaning solvents that will be purified according to the invention are synthetic aliphatic hydrocarbons, perchlorinated hydrocarbons, silicone solvents or mixtures thereof. Even more preferred, dry cleaning solvents are selected from the group consisting of perchlorethylene (perc), hydrocarbons, silicones, and mixtures thereof. Even more preferred, the dry cleaning solvents are selected from the group consisting of perc, decamethylcyclopentasiloxane, synthetic aliphatic hydrocarbons, in particular C11-15-ISO alkanes or C10-C13 isoparaffin and mixtures thereof. The most preferred cleaning solvent is perc. Additionally, it is more preferred that the dry cleaning solvents defined above do not contain methyl esters of fatty acids. The particles comprised in the adsorbent to be used according to the invention do not have a well-ordered structure, as is found in common clay minerals, such as bentonite or attapulgite, but comprise, in addition to a crystalline phase, which is preferably a Smectite clay phase, an amorphous phase, which is preferably an amorphous silica phase. The particles are preferably homogeneous on a macroscopic scale, that is, they can be described as an intimate mixture of both phases.

The amorphous phase of the particles comprised in the adsorbent to be used for the purification of the solvents for dry cleaning, according to the invention, represents preferably an amorphous silica phase. The amorphous phase of the particles can be analyzed by the signal-to-noise ratio when an X-ray diffraction analysis is used, as described below.

The crystalline phase of the particles comprised in the adsorbent to be used for the purification of the solvents for dry cleaning, according to the invention, preferably represents a layered silicate. It is further preferred that the crystalline phase of the particles represents a smectite phase, preferably a montmonillonite phase. The presence of a smectite phase can be detected by the methylene blue adsorption test, described further below. Generally, the crystalline phase can be detected by using X-ray diffraction analysis. I In a preferred embodiment of the invention, the particles to be used for the adsorbent comprise a continuous phase of amorphous silica, in which smectite phases are inserted in the form of small lamellae. The lamellae of the smectite phase are preferably homogeneously distributed in the continuous amorphous silica phase and fixed firmly therein. The structure of the particles, therefore, differs from the clay minerals that are currently used for the purification of solvents for dry cleaning. Even more preferred, the? particles that will be used for the purification of solvents for dry cleaning according to the invention, comprise a network similar to an amorphous Si02 matrix in which very small phases of smectite are inserted, and which can provide, surprisingly, a high adsorption capacity for the impurities contained in the solvent for dry cleaning. 1 The adsorbents which will be used for the purification of the solvents for dry cleaning according to the present invention, preferably are in the form of powders, agglomerates or granules, even more preferred in the form of agglomerates or granules. The adsorbents in the form of agglomerates or granules can be used favorably in cartridge filters. In addition, it is preferred that the adsorbents contain particles in powder form having a particle size of between 1 and 1000 μP, preferably between 1 and 700 mm and, more preferably, between 1 and 500 μm. It is further preferred that the adsorbents contain particles in the form of agglomerates or granules having a particle size between 0.01 and 10 mm, even more preferred between 0.05 and 4.0 mm. In a preferred embodiment, the particle size of the granular material is between 0.05 and 1.4 mm. In another preferred embodiment, the particle size of the granular material is between 0.2 and 1.6 mm. In a further preferred embodiment of the invention, the particle size of the granular material is between 1.2 and 4.0 mm. It will be understood that, with respect to preferred particle sizes as given above, at least 80, even more i preferred at least 90%, still more preferred at least 95% and more preferred at least 98 i % of the particles that comprise an amorphous phase and a crystalline phase, have the specified size.

According to the invention, adsorbents for purifying solvents for dry cleaning are preferably used in a suspended state or in an immobilized state. Preferably, the purification of solvents for dry cleaning comprises the removal of selected impurities from the group consisting of non-volatile residues, lint, colorants, grease, dirt, soaps and detergent residues.

The adsorbents that will be used for the purification of solvents for dry ejn cleaning can be synthetic materials or materials provided from a natural source, preferably, a material provided from a natural source. Such materials can be provided very easily, without prejudice to the environment and at a comparatively low cost, for example, from a respective mine. The adsorbents / particles that meet the requirements as described herein, and are suitable for the purification of solvents for dry cleaning, according to the present invention, can be easily found and identified by an expert. Suitable materials that can be used as particles (included in the adsorbents) can be obtained, for example, from the company Sued-Chemie (see experimental part). Additionally preferred, the particles comprised in the adsorbent have a surface area of 180 to 300 m2 / g, more preferred 185 to 280 m2 / g, even more preferred of 190 to 250 m2 / g when determined by the BET method. Additionally preferred, the particles possess a pore volume of more than 0.5 ml / g, particularly preferred of more than 0.55 ml / g, more preferred of more than 0.6 ml / g. In addition, the pore volume of the particles is less than 1.2 ml / g, still more preferred less than 1.0 ml / g and even more preferred less than 0.9 ml / g.

It is considered that the large pore volume allows quick access of solvenge for dry cleaning contaminated to the crystalline phases, for example, the smectite phases and, therefore, an efficient purification is achieved. It is considered, without being limited to this theoretical mechanism, that the favorable behavior of the adsorbent used in the method according to the invention is based on kinetic effects. In the clay minerals used so far as an adsorbent material, only the outer surface of the clay particles is available for rapid adsorption of the molecules. Such an external surface is much smaller than the internal surface of clay minerals when determined, for example, by BET methods. During adsorption, molecules, for example, dyes, are interspersed between layers in the crystalline structure of the clay mineral and the distance between layers increases. The clay mineral, therefore, dilates with the adsorption of molecules. The dilation starts at the outer surface of the clay particles, thereby blocking or at least making it difficult to access the additional molecules that will be adsorbed to the internal parts of the clay particles.

Contrary to the clay minerals used hitherto, the particles, as used in the method according to the invention, preferably comprise an amorphous Si02 matrix in which small particles of smectite minerals are inserted. The smectite particles are preferably largely divided into sheets and, therefore, provide a very high surface area for the adsorption of molecules, for example, dyes, etc. It is considered that the Si02 matrix is quite rigid, that is, the particles hardly dilate with the adsorption of, for example, dyes. Through the large pores provided in the particles, which are located in particular in the Si02 matrix, rapid access of the dry cleaning solvent contaminated to the crystalline phases inserted in the Si02 matrix is possible through the process of purification, since the particles barely dilate during the adsorption of the compounds present in the solvent for dry cleaning contaminated. This leads to a increased adsorption rate compared to the application of clay minerals used so far.

Additionally preferred, the particles comprised in the adsorbent used in the method according to the invention comprise at least 10% by weight, still more preferred more than 20% by weight and most preferred more than 30% by weight of a phase amorphous According to one embodiment of the invention, the amorphous phase forms less than 90% by weight, according to an additional embodiment, less than 80% by weight of the particles. The amorphous phase is preferably formed of SiO2. In addition to the amorphous phase, the particles used in the method of the invention preferably comprise a smectite phase. The particles preferably They comprise less than 60% by weight, more preferred less than 50%, even more preferred less than 40% by weight of a smectite phase. According to one embodiment of the invention, the smectite phase forms at least 10% by weight, according to a further embodiment, at least 20% by weight of the particles. The smectite phase / amorphous phase ratio is preferably within a range of 2 to 0.5, more preferred within 1.2 to 0.8.

In addition to the amorphous phase and the crystalline phase, additional minerals may be present in? the particles comprised in the adsorbent, preferably within a range from 0.5 to 40% by weight, more preferred from 1 to 30% by weight, particularly preferred from 3 to 20% by weight. Exemplary secondary minerals are quartz, cristobalite, feldspar and calcite. Other secondary minerals may also occur. The additional minerals referred to above may also be present in the adsorbent without necessarily being contained in the particles having an amorphous phase and a crystalline phase.

It is further preferred that the adsorbent to be used according to the present invention comprises at least 50% by weight, even more preferred at least 60% by weight, even more preferred at least 70% by weight, even more preferred by at least 80% by weight, still more preferred at least 90% by weight, even more preferred at least 95% by weight, of particles comprising an amorphous phase and a crystalline phase. In the most preferred embodiment of the invention, the adsorbent consists only of particles comprising an amorphous phase and a crystalline phase, as described above.

The structure of the adsorbents described above, and particles comprised in the adsorbents, can be detected by various experimental methods (see the experimental part).

As explained above, the preferred particles to be used in the method according to the invention have an amorphous silica phase in which crystalline phases are inserted, for example, small phases of smectite. The matrix formed preferably from amorphous silica "dilutes" the crystalline phases, for example, the smectite phases. This leads to a decrease in the signal to noise ratio of the reflections typical of the crystalline phase, for example, the smectite phase, which depends on the fraction of the crystalline phase. For example, the small angle reflections of montmorillonite are affected by the periodic distance between the layers of the montmorillonite structure.

Furthermore, if the crystalline phases fixed in the SiC02 matrix are divided into sheets to a large extent, this leads to a strong amplification of the corresponding diffraction peak.; In an XRD diffractogram of the particles comprised in the adsorbent used in the method of the invention, the reflections are barely visible above the noise. The signal to noise ratio for the reflections with respect to the particles, in particular the smectite phase, preferably approaches 1, even more preferred within a range of from 1 to 1.2. However, pronounced reflections can be visible in the diffractogram that originates from the impurities of the particles, for example, quartz. Such reflections are not considered for the determination of the signal-to-noise ratio.

Preferably, in the method of the invention particles are used that do not show, or hardly show, a reflection 001, which indicates the distance of the layers within the crystalline structure of the bentonite particles. Barely visible means that the signal to noise ratio of the reflection 001 of the smectite phase is preferably less than 1.2, particularly preferred i within a range of 1.0 to 1.1. J According to a preferred embodiment, the particles comprised in the adsorbent have an amorphous structure according to the XRD data. The amount of the amorphous silica phase and phase Crystalline, for example, smectite phase, present in the particles used in the method according to the invention, can be determined by a quantitative analysis of X-ray diffraction.

The details of such a method are described, for example, in "Hand Book of Clay Science", F. Bergaya, B. K. G. Therry, G. Lagaly (Eds.), Elsevier, Oxford, Amsterdam, 2006, Chapter 12.1: I. Srodon, Identification and Quantitative Analysis of Clay Minerals; "X-Ray Diffraction and the Identification and Analysis of Clay Minerals, "D. M. Moora and R. C. Reaynolds, Oxford University Press, New York, 1997, pp 765, included in this document for reference.

Quantitative X-ray diffraction is based on the Rietveld refinement formalism.

This algorithm was originally developed by H. M. Rietveld for the refinement of crystalline structures. The method is now commonly used in mineralogy and, for example, the cement industry for the quantification of mineral phases in unknown samples. j The Rietveld refinement algorithm is based on a calculated adjustment of a simulated diffraction pattern on a measured diffractogram. First, the mineral phases are determined by assigning peaks of the diffractogram. Based on the determined minerals, the diffractogram is then calculated based on the crystalline structure of the minerals present in the sample, as well as on the specific parameters of equipment and tests. In the following stages, the parameters The model is corrected to obtain a good adjustment of the calculated and measured diffractogram, for example, when using the minimum squares adjustment method. The details of the method are described, for example, in R. A. Young: "The Rietveld Method", Oxford University Press, 1995. The Rietveld method is able to reliably fix the reflections strongly superimposed on the diffractogram.

For the application of this method to the analysis of mineral samples see, for example, D. K. McCarthy "Quantitative Mineral Analysis of Clay-bean'ng Mixtures", in: "The Reynolds Cup" Contest. lUCr CPD Newsletter, 27, 2002, 12 - 16.

In practice, the quantitative determination of the different minerals in unknown samples is done by commercially available software, for example, "Seifert AutóQuan" available from Sejfert / GE Inspection Technologies, Ahrensburg, Germany. i I The particles comprised in the adsorbent, in particular when extracted from a natural source, preferably have a cation exchange capacity of more than 40 meq / 100 g., particularly preferred of more than 45 meq / 100 g and more preferred of 44 to 70 meq / 100 g. The high activity decolorizing soil, obtained by extracting a clay mineral with concentrated boiling acid, is characterized by a very low cation exchange capacity, usually of less than 40 meq / 100 g and, in most cases, less than 30 meq / 100 g. The particles used in the method according to the invention, therefore, can be clearly distinguished from the high performance decolorizing earth.

The so-called surface modified bleaching earths exhibit a cation exchange capacity similar to that of the particles used in the method according to the invention. Such surface activated bleaching soils, however, have a much lower pore volume and, therefore, can be clearly distinguished from the particles used in the method of the invention. Such surface modified bleaching earth does not allow easy access of the dry cleaning solvents contaminated to the internal parts of the clay particle, since these clay materials expand, as described above and, therefore, block additional access of the dry cleaning solvents contaminated to the spaces between the stratified silicate layers. Therefore, the adsorption speed of such surface-modified decolorizing earth is low.

The particles used in the method according to the invention are characterized by a high content of SiO2. In addition to silicon, other metals or preferred metal oxides may be contained in the particles or adsorbent. All percentages refer to dry particles at a constant weight at 105 ° C.

The particles preferably have a low aluminum content, calculated as' Al203, of less than 15% by weight, more preferred of less than 12% by weight, particularly preferred of less than 11% by weight and more preferred of less than 10% by weight. % in weigh. The aluminum content, calculated as Al203, according to one modality, is more than 2% by weight, according to an additional modality, more than 4% by weight, according to an additional modality, it is of more of 6% by weight and, according to still an additional embodiment, is more than 8% by weight. According to a further embodiment, the particles contain magnesium, calculated as MgO, in ! an amount of less than 7% by weight, preferably less than 6% by weight, particularly preferred less than 5% by weight. According to one embodiment of the invention, the particles contain magnesium, calculated as MgO, in an amount of at least 0.5% by weight, particularly preferred at least 1.0% by weight. According to a further embodiment, the particles contain at least 2% by weight of MgO.

According to a preferred embodiment, the particles may contain iron, calculated as Fe203, in an amount of less than 8% by weight. According to an adjunctional modality, the iron content, calculated as Fe203, can be less than 6% by weight and, according to even an additional embodiment, it can be less than 5% by weight. According to a further embodiment, the particles may contain iron, calculated as Fe203, in an amount of at least 1% by weight and, according to still an additional embodiment, in an amount of at least 2% by weight. j The inventors consider that the distribution of the pore diameter of the particles has a considerable effect on the activity of the adsorbent. In a first embodiment of the method of the invention, in order to obtain a high adsorption activity, it is preferred that the particles used are characterized in that at least 60%, preferably 65 to 70% of the total pore volume of the particles, is provided by pores having a pore diameter of at least 140 A, at least 40%; preferably at least 50%, particularly preferred 55 to 60% of the total pore volume is provided by pores having a pore diameter of less than 250 A, and at least 15%, more preferred by at least 20%, particularly Preferred 21 to 25% of the total pore volume is provided by pores having a pore diameter of 140 to 1250 A. Preferably, less than 20% of the total pore volume, particularly preferred less than 15%, more preferred 10 to 14% of the total pore volume is formed by pores having a diameter of > 800 Á. | Additionally preferred, at least 20%, preferably at least 25%, Particularly preferred at least 30% and more preferred 33 to 40% of the total pore volume of the particles is provided by pores having a pore diameter of less than 140 A.

Additionally preferred, at least 10%, preferably at least 13%, particularly preferred 15 to 20% of the total pore volume of the particles according to the first embodiment of the method according to the invention, is provided by pores having a diameter of pore from 75 to 140 Á.

Even more preferred, less than 40%, preferably less than 35%, particularly preferred 25 to 33% of the total pore volume of the particles is formed by pores having a pore diameter of 250 to 800 A.

Further preferred, less than 80%, more preferred less than 75%, particularly preferred 60 to 70% of the total pore volume of the particles is formed by pores having a pore diameter of greater than 140 A.

Additionally preferred, less than 60%, preferably less than 50%, particularly preferred 40 to 45% of the total pore volume of the particles is formed by pores having a pore diameter of at least 250A. ' The preferred ranges of the total pore volume in relation to the pore diameter are summarized in the following table 1: Table 1: preferred percentages of the total pore volume formed by pores of a different pore diameter for particles used in a first embodiment of the purification method according to the invention. ! preferred preferred pore diameter most preferred 0 -. 0 -. 0 - 75 A > 12% > 14% 15 - 20% 75 -. 75 - 140 A > 10% > 13% 15 - 20% 140 -. 140 - 250 A > 15% > 20% 21 - 25% 250 -. 250 - 800 A < 40% < 35% 25 - 33% > 800 A < 20% < 15% 10 - 14% According to a second embodiment, in the method according to the invention particles are used in which preferably at least 20%, preferably at least 22% of the pore volume, particularly preferred 20 to 30% of the total pore volume is formed by pores having a pore diameter of less than 75 Á. j Additionally preferred, at least 45%, particularly preferred at least 50% of the total pore volume of the particles used according to the second embodiment of the method according to the invention, is provided by pores having a pore diameter of less than 140 Á. ' In addition, preferably less than 40%, particularly preferred less than 35% of the total pore volume is formed by pores having a pore diameter of greater than 250 A. The particles used in the second embodiment of the method according to the invention comprise just a low amount of large pores. However, an efficient purification of solvents for dry cleaning is possible within an acceptable timeframe for an industrial application. In Table 2, the preferred action of the pore volume provided by pores having a defined pore diameter is summarized.

Table 2: preferred percentages of the total pore volume formed by pores of a different pore diameter for particles used in a second embodiment of the purification method according to the invention. pore diameter percentage preferred percentage particularly preferred 0 - 250 A > 55% 60 - 80% 0 -. 0 - 800 A < 90% 70 - 85% > 800 A < 30% 10 - 25% 75 -. 75 -. 75 - 140 A < 40% 20 - 35% 140 -. 140 - 250 A < 25% 10 - 20% 250 -. 250 - 800 A < 20% 5 - 20% 75 - 800 A < 65% 50 - 60% > 75 A < 85% 60 - 80% > 140 A < 60% 30 - 50% > 250 A < 40% 25 - 35% The adsorbent used in the method of the invention preferably reacts from neutral to slightly alkaline. A suspension aMO% by weight of the adsorbent in water preferably has a pH in the range of 5.5 to 9.0, particularly preferred 5.9 to 8.7, more preferred 7.0 to 8.5j The pH is determined with a pH measuring electrode in accordance with DIN ISO 7879 .

According to a preferred embodiment, the adsorbents / particles to be used according to the invention do not have to be activated, in particular by acid treatment.

Preferably, the granular adsorbent is used in dry cleaning machines with cartridge filtration (cartridges in large format or fixed nylon disk filters accompanied by a cartridge in small format) and, optionally, (mostly not necessary) a Distillation unit. The granular product can filter hydrocarbons, perc, or silicones.

The present invention also relates to a filter unit containing an adsorbent comprising particles, which in turn comprise an amorphous phase and a crystalline phase, as defined above. Preferably, the filter contains the adsorbent in a suspended state or in an immobilized state. More preferably, the filter represents a cartridge filter comprising the adsorbent in an immobilized state.

In a preferred embodiment, the filter unit is a filter cartridge that contains the adsorbent in the dry state before use. Even more preferred, the filter cartridge is a tower or paper filter. Preferably, paper filters are disposable products, which can be replaced after use. Preferably, the filter has a porous paper wall or a perforated steel wall to prevent fine particles from diffusing out of the cartridge.

The present invention also relates to a dry cleaning machine containing a filter unit, as defined above.

The present invention also relates to a process for dry cleaning textiles, wherein the textiles are washed using at least one solvent for dry cleaning, and wherein the solvent or solvents for dry cleaning are purified using at least one adsorbent comprising particles which in turn comprise an amorphous phase and a phase crystalline All the preferred adsorbents / particles, as described above, can preferably be used in the process for dry cleaning textiles, according to the invention. If the adsorbent is used in the form of a powder, it is preferably suspended in the solvent or solvents for dry cleaning during the purification of the solvent or solvents for dry cleaning, and the adsorbent is separated from the solvent or solvents for dry cleaning when using a solvent. filter, in particular a nylon disc filter. If the adsorbent is used as granulates or agglomerates, it is preferred to use a filter cartridge containing the adsorbent. Preferably, the solvent (s) for dry cleaning are purified by using a filter unit according to the invention. I i DESCRIPTION OF THE FIGURES Figure 1 shows a simplified diagram for a dry cleaning process using I perc as the solvent for dry cleaning and an integrated carbon cartridge for filtration.

Figure 2 shows a simplified diagram for a dry cleaning process lysing perc as the solvent for dry cleaning and a nylon disc filter for filtration.

Figure 3 shows a simplified diagram for a dry cleaning process using perc as the solvent for dry cleaning and an integral granular adsorbent for filtration. It is not necessary to carry out a distillation of the solvent for dry cleaning in this process; í METHODS The physical attributes used to characterize the particles / adsorbents used in the method according to the invention are determined as follows: Surface and specific pore volume The specific pore surface and volume are determined by the BET method (single-point method using nitrogen, in accordance with DIN 66131) with a pore meter.

Automatic nitrogen from Micrometrics, type ASAP 2010. The pore volume was determined using the BJH method (E. P. Barrett, L. G. Joyner, P.P. Hienda, J. Am. Chem. Soc. 73 (1951) 373). The pore volumes of defined pore diameter ranges were measured by summarizing increasing pore volumes, which were determined from the adsorption isotherm according to BJH. The total pore volume refers to pores having a diameter of 2 to 350 nm. The measurements provided as additional parameters the micropore surface, the external surface and the micropore volume. Micropores refer to pores that have a pore diameter of up to 2 nm according to Puré &; Applied Chem. Vol. 51, 603-619 (1985).

Humidity The amount of water present in the adsorbent / particles at a temperature of 105 ° C was determined in accordance with DIN / ISO-787/2.

Silicate analysis The adsorbent / particles completely disintegrated. After dissolution of the solids, the compounds were analyzed and quantified by specific methods, for example ICP. a) disintegration of samples] A 10 g sample of the adsorbent / particles is ground to obtain a fine powder that is dried in an oven at 105 ° C until a constant weight is reached. About 1.4 g of the dried sample are deposited in a platinum bowl and the weight is determined to an accuracy of 0.001 g. The sample is then mixed with 4 to 6 times in excess (weight) of a mixture of sodium carbonate and potassium carbonate (1: 1). The mixture is placed in the platinum bowl in a Simon-Müller oven and melted for 2 to 3 hours at a temperature of 800 - 850 ° C. The platinum bowl is removed from the oven and cooled to room temperature. The solidified melt is dissolved in distilled water and transferred to a beaker. Then concentrated hydrochloric acid is added carefully. After the evolution of gas has ceased, the water evaporates in such a way that a dry residue is obtained. The residue is dissolved in 20 ml of concentrated hydrochloric acid, followed by evaporation of the liquid. The process of dissolving in concentrated hydrochloric acid and evaporating the liquid is done once more. The residue is then moistened with 5 to 10 ml of acid aqueous hydrochloric (12%). About 100 ml of distilled water are added and the mixture is heated. To remove the insoluble Si02, the sample is filtered and the residue remaining in the filter pad is completely washed with hot hydrochloric acid (12%) and distilled water until chlorine is no longer detected in the filtrate. j b) silicates analysis The Si02 is incinerated together with the filter paper and the residue is weighed. \ c) determination of aluminum, iron, calcium and magnesium | The filtrate is transferred to a calibrated flask and distilled water is added to the calibration mark. The amount of aluminum, iron, calcium and magnesium in the solution is determined by FAAS. j d) determination of potassium, sodium and lithium j A sample of 500 mg is weighed in a platinum bowl with an accuracy of 0.1 mg. The sample is moistened with about 1 to 2 ml of distilled water and then four drops of concentrated sulfuric acid are added. About 10 to 20 ml of concentrated hydrofluoric acid are added and the liquid phase is evaporated to dryness in a sand bath. This process is done again three times. Finally, H2SO4 is added to the dry residue and the mixture is evaporated to dryness in a baking sheet. The platinum bowl is calcined and, after cooling to room temperature, 40 ml of distilled water and 5 ml of hydrochloric acid (18%) are added to the residue and the mixture is heated to boiling. The solution is transferred to a calibrated flask of I 250 ml and water is added to the calibration mark. The amount of sodium, potassium and lithium in the solution is determined by EAS.

Loss on ignition, In a bowl of calcined and heavy platinum, about 0.1 g of a heavy sample is deposited with an accuracy of 0.1 mg. The platinum bowl is calcined for 2 hours at 1000 ° G in an oven. Then, the platinum bowl is transferred to a desiccator and weighed. ! Ion exchange capacity j The adsorbent / particles to be tested are dried at 150 ° C for two hours. Then he j - 2. 3 - Dry material is allowed to react under reflux with a large excess of aqueous NH 4 Cl solution for 1 hour. After being left at room temperature for 16 hours, the material is filtered. The filter residue is washed, dried and crushed, and the NH 4 content in the adsorbent / particles is determined by the Kjedahl method. The quantity and class of the metal ions exchanged is determined by ICP spectroscopy.

XRD The XRD spectra are measured with a X'- Pert-MPD powder diffractometer (Pw! 3040) (Phillips), equipped with a Cu anode.

Determination of sediment volume: A 100 ml graduated glass cylinder is filled with 100 ml of distilled water or with an aqueous solution of 1% sodium carbonate and 2% trisodium polyphosphate. 2 g of the compound to be analyzed are placed on the surface of the water in portions of about 0.1 to 0.2 g with a spatula. After the sinking of a portion, the next portion of the compound is added.

I After adding 2 g of the compound to be analyzed, the cylinder is maintained at room temperature for one hour. Then, the volume of sediment (ml / 2g) is read from the graduation. j Determination of the proportion of montmorillonite by methylene blue adsorption I a) Preparation of a tetrasodium diphosphate solution I 5. 41 g of tetrasodium diphosphate are weighed to an accuracy of 0.001 G in a flask I calibrated 1000 ml and the flask is filled to the calibration mark with distilled water and stirred repeatedly. j b) Preparation of 0.5% methylene blue solution In a 2000 ml beaker, 125 g of methylene blue dissolve in about 1500 ml of distilled water. The solution is decanted and then distilled water is added to a I volume of 25 I. 0.5 g of wet test bentonite having a known internal surface is weighed into an Erlenmeyer flask with an accuracy of 0.001 g. 50 ml of tetrasodium diphosphate solution are added and the mixture is heated to boiling for 5 minutes. After cooling to room temperature, 10 ml of H2SO4 (0.5 M) are added and 80 to 95% of the expected consumption of methylene blue solution is added. With a glass rod, a drop of the suspension is transferred to a filter paper. A dark blue spot forms, surrounded by a crown without color. Additional solution of methylene blue is added in 1 ml portions and the drop test is performed again until the corona surrounding the dark blue spot shows a slightly blue color, ie the added methylene blue is no longer adsorbed for the test bentohite. c) Analysis of the particles' The test of the particles is carried out in the same way as described for the bentonite test. Based on the consumed solution of methylene blue, the internal surface of the particles is calculated.

According to this method, 381 mg of methylene blue / g of particles correspond to a content of 100% montmorillonite.

Determination of particle size (dry sieve residue) Through a sieve cloth, a vacuum connected to the sieve sucks, in a suction opening surrounding below the perforated bottom of the sieve, all particles that are finer than the inserted sieve, which will be covered at the top with a cover of acrylic, and leaves the thickest particles in the sieve. The experimental procedure is as follows: Depending on the product, between 5 and 25 g of air-dried material are weighed and placed in the sieve. Subsequently, the acrylic cover is placed over the screen and the machine is turned on. During the air jet selection, the selection process can be facilitated by striking the acrylic cover using the rubber hammer. The time of exhaustion is between 1 and 5 minutes. The calculation of the dry residue in% is as follows: real weight multiplied by 100 and divided by the initial weight.

Apparent weight Weigh a calibrated glass cylinder of 1 I, cut at the 1000 ml mark. For a powder funnel, the sample is poured into the cylinder in a single stage, in such a way that the cylinder is completely filled and a cone is formed on the top of the cylinder. The cone is removed with the help of a ruler, and the material adhering to the outside of the cylinder is removed. The full cylinder is weighed again and the apparent weight is obtained by subtracting the weight of the empty cylinder.

X-ray diffraction analysis 1 to 2 g of sample were hand-ground by hand in an agate mortar and then passed through a 20-μm sieve. This process was carried out again until the complete sample passed the sieve. For the measurement of X-ray diffraction, a Siemens D5000 equipment was used. The following measurement conditions were used: Plastic sample holder, "top load", 0 = 25 mm Thickness of the powder layer 1 mm Cu Ka X-ray tube: 40 kV / 40 mA I Diffraction angles 2 - 80 ° (2 T) Measuring time 3 s per stage j Openings Primary and secondary divergence openings of 1 mm The qualitative evaluation of the diffractograms (the allocation of the mineral phase was carried out with a computer program "EVA" by Bruker AXS GmbH, Karisruhe and in agreement, with the í Brindley & amp; Brown (1980): Crystal structures of clay minerals and their! X-ray Identification. - Mineralogical Society No. 5, 495. The quantitative evaluation was carried out according to the Rietveld method, using the AutoQuan computer program of the company j Seifert (GE Inspection Technologies, Ahrensburg, Germany) based on the Rietveld method (see description); for the determination of the content of amorphous materials by X-rays, zincite was added as internal standard. For the background correction, a fourth order polynomial was used in the angle range of 4 - 80 ° in 2?. ( i The volatile compounds were determined using the EPA method 24 (Agency for i Protection of the United States Environment). In the EPA Method 24, the percentage weight of I Volatile ingredients are determined by following ASTM D2369, the Standard Test Method for the Volatile Compound Content of the Coatings. ' Water and sediments were determined following ASTM D 2709. Microorganism counts, bacteria, were determined using ASTM E 1259. The acid number was determined using ASTM D 974a. | EXAMPLES Example 1: General characterization of particles included in the adsorbents I used for the purification of solvents for dry cleaning The properties of the particles comprised in the adsorbents used in the examples, according to the invention, are summarized in Table 3. In the dry-cleaning experiments of the examples, the adsorbents consisted only of the particles having a phase amorphous and a crystalline phase. However, it is possible to use suitable additives or minerals, in addition to the particles, as described in this document. An expert knows suitable additives for use in the method of solvent purification for dry cleaning. j Particles with the reference number "1" can be obtained under the trade name Tonsil® ULTRA .de SUD CHEMIE DE MÉXICO, SA de CV Particles with the reference number "2" can be obtained from SUD CHEMIE DE MEXICO, SA de CV under the trade name Tonsil® PLUS F. The particles with the reference number "3" can be obtained from SUD CHEMIE DE MÉXICO, SA de CV under the trade name Tonsil® PLUS M. Table 3: properties of the particles used in the examples Particles 1 2 3 Tonsil® 414 FF Dry sieve residue in 45 49 100 100 32.7 pm (%) Dry sieve residue in 63 35 99.8 99.3 22.9 pm (%) Particle size less than - 33.0 5.2 - 0. 25 mm,% Particle size greater than 1 .0 1 .2 1 .40 mm,% Apparent weight (g / l) 292 618 623 580 Adsorption of methylene blue 106 28 108 176 (mg / g sample) Moisture content (%) 8.0 3.0 2.3 10.0 pH (10% by weight in water) 7.6 7.9 8.1 6.0 Exchange capacity 52 44 53.3 cationic (meq / 100 g) BET surface (m ^ / g) 208 180 140 224.

Micropore area (rn ^ / g) 32.1 21 16 - external surface (m ^ / g) 176.3 159 124 214 micropore volume (cma / g) 0.016 0.01 1 0.008 cumulative pore volume 0.825 0.379 0.297 (BJH) for pore diameter 1. 7 -300 nm (cm3 / g) average pore diameter 16.4 10.3 10.3 (BJH) (nm) sediment volume (ml / 2g) 5.5 3 4 - In example 2, the commercially available surface-modified decolorizing earth, Tonsil® 414 FF, which can be obtained from Süd-Chemie AG, Germany, has been used.

The chemical composition of the particles used in the examples is summarized in Table 4. Table 4: Chemical composition of particles / adsorbents Adsorbent 1 2 3 Tonsil® 414 FF S02 70.6 69.4 69.4 65.0 Fe203 2.8 3.4 3.4 2.5 Al203 9.8 9.9 9.9 13.0 MgO 4.1 3.1 3.1 1.5 CaO 1 .4 2.5 2.5 5.7 K20 1 .5 1.3 1.3 1 .1 Na20 0.26 0.94 0.94 0.4 T02 0.25 0.38 0.38 1.18 Loi (1000 ° C) 7.9 8.1 8.1 9.8 I Characterization of particles 1 and 2 by X-ray diffraction X-ray diffraction measurements were made according to the general description for the method. The results are listed in table 5.

Table 5: Quantitative determination of the mineral phase by X-ray diffraction Mineral phase 1 2 Smectite { % by weight) 40 40 Itlita / Muscovite (% by weight) Traces n.d.

Kaolinite (% by weight) n.d. 1 Sepiolite (% by weight) 1 1 n.d.

Quartz (% by weight) Traces 1 Orthoclase (% by weight) 12 8 Plagioclase (different) (% by weight) 3 1 1 Calcite (% by weight) Traces 1 Amorphous material (% by weight) 34 38 The results of the quantitative X-ray diffraction analysis show the presence of smectitic phases in particles 1 and 2, as used in the method according to the invention. In addition, various secondary minerals can be found, such as sepiolite for particles 1, orthoclase, plagioclase (other feldspars), calcite. The X-ray diffraction shows the presence of more than 30% of amorphous material for both types of particles. The amorphous phase of the particles 2 is scarcely present in the same concentration as the smectite phase (ratio 100: 95), while in the particles 1, the ratio of smectite to amorphous material is 100: 85. These analyzes show that the particles used in the method according to the invention exhibit a completely new structure, in comparison with the standard smectites. The presence of the high amount of amorphous material, which can be mostly indicated as amorphous silica due to the high Si02 content in the silicates analysis, also explains the high porosity of the particles used in the method of the invention.

Example 2- Comparison between the combination Tonsil® / DE and an adsorbent according to the invention in powder form: The experiments with adsorbents in powder form were carried out in dry cleaning machines, which can be obtained from Kelleher Equipment Supply Inc, EÜ, under the trade names "Forcé" and / or "Bergparma". j During the solvent purification process, which is typically carried out when the solvent is very dark, avoid darkening of light-colored fabrics, the nylon spinning disc filter of the dry-cleaning machine is pre-coated with the adsorbents. The nylon spinning disc system is coated with either a Tonsil® 414 FF (0.454 kilogram (1 pound)) / DE (or 464 kilograms (1 pound)) (50:50) combination or the Tonsil® powder adsorbent ULTRA (0.454 kilograms (1 pound)) for a dry cleaning machine of 15,876 kilograms (35 pounds) capacity, equipped with a rotating disc filter. In this experiment Perc was used as the solvent for dry cleaning.

A plastic bag is filled with the powders and placed in the washing chamber. The The machine was started as normally started for the wash cycle and the solvent was placed in the i the washing chamber. The adsorbents came in contact with the solvent for dry cleaning.

Some minutes of rotation ensure good good contact between the adsorbent and the solvent for dry cleaning. Then, the pump was ripped off to empty the adsorbent / solvent suspension for dry cleaning, and pump it to the nylon rotating disk filter, the solvent passing through the filter is diverted to the washing chamber and returned back to the filter rotary; This recirculation process is continued for approximately ten minutes. This process covers the discs with Tonsil® 414 FF / diatomaceous earth and / or Tonsil® LjLTRA, respectively-. The solvent is allowed to purify with a recirculation process and, after this, the solvent is cleaned again and the machine is ready to clean clothes again.

At the end of the solvent purification, the filter is flooded with solvent in order to wash the adsorbent layer, and the discharged solvent is diverted to a compartment with mesh cloth where the adsorbent is separated and the solvent is drained by gravity during several hours to discard the solids, and the recovered solvent can be added back to the machine. j To compare the properties of a Tonsil® 414 FF / DE combination with the properties of a powder adsorbent according to the invention, dry cleaning solvents, after 12 wash cycles, where each wash cycle comprises washes of 15,876 jkg (35 Ib) of clothes and uses the same solvent again and again at a rate of 3,785 liters (one gallon) of solvent / 0.454 kg (1 Ib) of clothes, which means 132,489 liters (35 gallons) reused 12 times in a machine? 5,876 kg (35 Ib), were compared with each other.

The experiment showed that the dry cleaning solvent was cleaner when 0.454 kilograms (one pound) of the powder adsorbent was used according to the invention, compared to the use of 0.907 kilograms (two pounds) of the 'Tonsil' mixture. ® 414 FF / DE. In addition, the pressure drop in the solvent pump during the operating condition was lower for the powder adsorbent according to the invention, indicating better filtration properties. The results showed that DE is not required when using the powder adsorbent according to the invention. Furthermore, it was shown that the cleaning capacity of the powder according to the invention is more than the cleaning capacity of the Tonsil® 414 FF / DE mixture. The The filtration properties of the powder adsorbent according to the invention were very good with respect to all kinds of clothes.

Example 3: In the examples with adsorbents in granular form, the dry cleaning machines obtainable from Kelleher Equipment Supply Inc, EU, under the trade names "Forcé" and / or "Bergparma" were used.

The experiment was carried out using a steel basket filter; this filter was filled with the granular adsorbent (s) according to the invention. The filter has a porous wall of paper or a perforated steel wall to prevent fine particles from diffusing out of the basket. The particle size of the adsorbent varied in the range of 75 microns to 1000 microns, the adsorbent had at least 90% of the particles in this range. For reasons of comparison, the use of the granular adsorbent according to the invention was compared to a traditional distillation system.

In order to analyze the efficiency in the purification during the washing process, a reference sample of the solvent was collected at the beginning of the test; Fresh and clean solvent was analyzed and used as a reference for future results using granular adsorbent to purify solvents. j During the washing process, the dry cleaning solvent was occasionally diverted through the cartridges until the solvent reached an acceptable level of clarity, which could be evaluated when the solvent passed through a glass window in the system of recovery, this operation can be performed manually when, for the opinion of the opérador, the solvent contains visible dyes or loses clarity. Solvent samples were collected at different operating intervals, typically measured in kilograms (pounds) of clean clothes, starting from when the machine was fed with fresh, clean solvent, and using a fresh filter cartridge with granular adsorbent, ie , a cumulative value that reflects the number of cumulative kilograms (pounds) that could be cleaned by a cartridge before the cartridge loses its power or becomes saturated with impurities.

All solvent samples were analyzed for water content, non-volatile residues, bacterial content and fatty acid content. With the reintroduction of a new granular adsorbent cartridge, the solvent is circulated through the cartridges and rinsed. Another sample of solvent is taken to measure the reduction of impurities by replenishing the granular adsorbent powder. j The results of the analysis of the solvent for dry cleaning during the process of avacado are summarized in table 6 below. Table 6 shows that the use of the granular adsorbent according to the invention could be more effective than the use of a distillation unit in the machine, which eliminates the energy used in the heater and cooling devices, vapor emissions and possibly the need for a complete distillation unit} in the machine, which leads therefore to potential savings by avoiding those costs.

Table 6: Analysis of solvents for dry cleaning during the washing process Description Material no Water and Fatty Acid Count volatile index (%) Sediment Bacteria / ml total acid mg (%) KOH / g Solvent DF 2000 dials 4.60 < 0.05 Nothing 0.01 new Solvent DF 2000 after 0.38 < 0.05 Nothing 0.06 of 1, 010 # Solvent DF 2000 after 1.58 < 0.05 Nothing 0.20 of 2,400 # Solvent DF 2000 after 1.10 < 0.05 Nothing 0.22 of 6,500 # Solvent DF 2000 after 3.08 < 0.05 Nothing 0.22 of 10,900 # KR Clay Filtration 0.93 < 0.05 Nothing 0.06 Item Activated by Solvent Solvent after 0.35 < 0.05 Nothing 0.13 Material Circulation Granular Tonsil® / Coal Division 1.28 < 0.05 Nothing 0.22

Claims (13)

CLAIMS I

1. A use of an adsorbent comprising particles which in turn comprise an amorphous phase and a crystalline phase for the purification of solvents for dry cleaning. j

2. The use according to claim 1, wherein an amorphous phase of the particles represents an amorphous silica phase.

3. The use according to claim 1 or 2, wherein a crystalline phase of the particles represents a layered silicate. I

4. It was used according to any one of claims 1 to 3, wherein a crystalline phase of the particles represents a smectite phase, preferably a montmorillonite phase.

5. The use according to any of the preceding claims, wherein the adsorbent is used in the form of powders, agglomerates or granules.

6. The use according to any of the preceding claims, wherein the adsorbent is used as a powder with a particle size between 1 and 1000 μm, or j as agglomerates or granules with a particle size between 0.01 and 10 mm.

7. The use according to any of the preceding claims, wherein the adsorbent is used in a suspended state or in an immobilized state. i

8. The use according to any of the preceding claims, wherein the dry cleaning solvents are selected from the group consisting of perchlorethylene (PERC), hydrocarbons, silicones and mixtures thereof.

9. The use according to any of the preceding claims, wherein the purification of the solvents for dry cleaning comprises the removal of impurities. Selected from the group consisting of non-volatile residues, lint, colorants, grease, dirt, soaps and detergent residues. J 10. A filter unit containing an adsorbent as defined in any of claims 1 to 6. The filter unit according to claim 10, wherein the filter unit is a filter cartridge, preferably with paper means, or a carbon tower filter. 12. A dry cleaning machine containing a filter unit as defined in claim 10 or 11. 13. A process for the dry cleaning of textiles, wherein the textiles are washed using at least one solvent for dry cleaning, and wherein the solvent or solvents for dry cleaning are purified using at least the adsorbent as defined in Claims 1 to 6. 14. The process according to claim 13, wherein the adsorbent is suspended in the solvent or solvents for dry cleaning during the purification of the solvent or solvents for dry cleaning, and wherein the adsorbent is separated from the solvent (s) for cleaning dry using a filter, in particular a nylon disc filter or a filter cartridge. 15. The process according to claim 13, wherein the solvent or dry cleaning solvents are purified using a filter unit according to claims 10 or 11. AMENDED CLAIMS received by the International Bureau on October 8, 2009 (08.10.2009) 1. A use of an adsorbent comprising particles which in turn comprise upa amorphous silica phase i and a smectite phase for the purification of solvents for dry cleaning, wherein the smectite phase / amorphous phase ratio is within a range of 2 to 0.5. 2. The use according to claim 1, wherein the smectite phase represents a montmorillonite phase. 3. The use according to any of the preceding claims, wherein the adsorbent is used in the form of powders, agglomerates or granules. 4. The use according to any of the preceding claims, wherein the adsorbent is used as a powder with a particle size between 1 and 1000 μ? T ?, oj as agglomerates or granules with a particle size between 0.01 and 10 mm. 5. The use according to any of the preceding claims, wherein the adsorbent is used in a suspended state or in an immobilized state. 6. The use according to any of the preceding claims, wherein the I Solvents for dry cleaning are selected from the group consisting of perchlorethylene (PERC), hydrocarbons, silicones and mixtures thereof. 7. The use according to any of the preceding claims, wherein the purification of the solvents for dry cleaning comprises the removal of impurities selected from the group consisting of non-volatile residues, lint, colorants, grease, dirt, soaps and detergent residues. . 8. A filter unit containing an adsorbent as defined in any one of claims 1 to 4. 9. The filter unit according to claim 8, wherein the filter unit is a filter cartridge, preferably with means of paper, or a carbon tower filter.

10. A dry cleaning machine that contains a filter unit as defined in

Claim 8 or 9. 1. A process for the dry cleaning of textiles, wherein the textiles are washed by using at least one solvent for dry cleaning, and wherein the solvent or solvents for dry cleaning are purified using at least the adsorbent as defined in claims 1 to 4.

12. The process according to claim 11, wherein the adsorbent is suspended in the solvent or solvents for dry cleaning during the purification of the solvent or solvents for dry cleaning, and wherein the adsorbent is separated from the solvent (s) for cleaning in dry using a filter, in particular a nylon disc filter or a filter cartridge. j i

13. The process according to claim 11, wherein the solvent or dry cleaning solvents are purified using a filter unit according to claims 8 or 9. Declaration according to Article 19 (1) PCT Within the new claim 1, the term "amorphous phase" has been specified as "amorphous silica phase", and the term "crystalline phase" has been specified as "smectite phase", as claimed above within the preceding claims 2 and 3/4. The particles comprising an amorphous silica phase and a smectite phase with a smectite to amorphous phase ratio in the range of 2 to 0.5, and the use thereof as an adsorbent for the purification of solvents for dry cleaning, they have not been disclosed within the cited state of the art. The subject matter of the present claims 1 to 13 is therefore novel in view of the aforementioned state of the art. In addition, it has been found that adsorbents comprising particles with an amorphous silica phase and a smectite phase with a ratio of 2 to 0.5 (smectite: silica) provide and lead to particularly favorable and exceptionally good solvent purification results for dry cleaning (table 5 under example 1 and page 34, lines 23/24 in relation to examples 2 and 3). The use of the present claim 1 is not only novel but also based on an inventive step, in view of the aforementioned state of the art.