TANNING PROCESS WITH RECOVERY OF WATER AND CHEMICALS.

Description

Z205479 -1- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl DESCRIPTION of the industrial invention entitled: TANNING PROCESS WITH RECOVERY OF WATER AND CHEMICALS on behalf of RENBERTECH SRL, with headquarters in TRISSINO (VI). DESCRIPTION TEXT The present invention relates to a tanning process with recovery of water and chemicals. More specifically, it refers to a process tanning plant where water and chemical products are recovered starting from liquid effluents resulting from various treatments tanning and retanning of hides and skins. As is known, tanning is an industrial process that transforms raw animal skins made of leather that can be used for various purposes products. Retanning is a further treatment of the leather that is performed after tanning to improve the properties of leather, such as its softness, elasticity, color and water resistance. These processes require intensive use of water and chemicals, which can have a significant impact on the environment. Therefore, the recycling of both water and chemicals in tanning processes is crucial to make the most sustainable industry. To remove contaminants and harmful chemicals from waters used in the tanning processes are known to resort to various techniques, including sedimentation, which allows for remove suspended solids, and filtration, which allows Z205479 -2- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl further cleaning of the water through filters. Waste water can also undergo processes of biological oxidation, which essentially consists in the use of bacteria to decompose organic materials, and disinfection with chlorine or other methods that eliminate pathogens. The treated water can be reused in the various stages of tanning processes, such as washing the hides, reducing the demand for fresh water and minimizing environmental impact. As regards the recovery of chemical products, and in particular of chromium which is one of the main agents tanning agents used, precipitation is generally used chemistry, obtained by adding substances that form compounds insoluble with chromium, which can then be removed, or with the use of membrane technologies that allow for filtration advanced to separate chromium from water. Sulphates and chlorides can instead be recycled and reused in tanning baths through processes chemical separation, while enzymes and biological products can be recycled and used in further treatment cycles of the skins. Recovery of water and chemicals in tanning processes varies depending on several factors, including the type of process, the technologies used and resource management practices adopted by the tanning company. In particular, as regards washing water, which Z205479 -3- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl represent a large portion of the water used in processes traditional tanneries, they can be recovered in large quantities up to 60-70% of the water used. Waste water, on the other hand, can generally be reused in a more significant percentage, often up to 80-90%. Through the processes of precipitation and filtration above mentioned, it is possible to recover up to 98% of the chromium used. The recovery of tanning agents is more complex, but they can extraction and reuse methods of extracts should be used tannic, recovering up to 50-60% of them. Other chemicals, such as salts and bleaching agents imbibition, can be partially recovered and reused. The recovery percentage varies according to the type of substance and technology used, but often it hovers around at 40-60%. From the above it is evident that there is a large margin for improve the recycling of water and chemicals in processes tanners, and how this represents a fundamental step for make this industry more sustainable, reducing the impact environmental and optimizing the use of resources. The aim of the present invention is therefore to improve the efficiency performance of systems recovery of water and chemical products from industry Z205479 -4- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl tanning, eliminating the drawbacks of the prior art cited and therefore carrying out a tanning process with recovery of water and chemicals essentially in a closed cycle, which allows to minimize the use of new resources and maximize the recovery. Within the scope of the above task, a particular purpose of the invention is to create a tanning process that allows to reduce the quantity of chemical waste and water contaminated not reused. Another object of the invention is to provide a tanning process that reduces the demand for clean water and new chemicals, reducing operating costs. A further object of the invention is to provide a tanning process that reduces pollution of water bodies and of the soil, contributing to the sustainability of the industry tanning. Another purpose of the invention is to create a tanning process that allows for greater flexibility of use of water and chemicals, compared to their almost total recoverability. Not least aim of the invention is to make available provision of a tanning process that gives the possibility of handle the chemicals used in such a way as to avoid contamination with other products (cross contamination). The above mentioned task and purposes, as well as others that better Z205479 -5- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl they will appear later, they are reached by a tanning process with recovery of water and chemicals including at least the phases of: - place one or more skins into a containment chamber thermally insulated from the outside, in which temperature, humidity and humidity are constantly monitored amount of liquid present inside; - treat said skins, feeding said chamber with containment of a treatment liquid in nebulized form chosen from the group comprising water or a mixture thereof with one or more chemical products suitable for giving said skins desired mechanical, physical and aesthetic properties; - extract said skins from said containment chamber; characterized by the fact that, subsequently to the said phase of treating said skins, a rinsing procedure is included including at least the phases of: - discharge the treatment liquid not absorbed by said skins from said containment chamber; - accumulate said unabsorbed treatment liquid by said skins in a collection tank; - rinse said containment chamber, feeding said containment chamber a chosen rinsing liquid in the group comprising water or a mixture thereof with one or more cleaning products; - discharge contaminated rinsing liquid after use from Z205479 -6- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl said containment chamber; - collect said contaminated rinsing liquid after use in the said collection tank; - treat the liquid accumulated in said tank collection, in such a way as to separate the water from the products chemists; - recover said water and said chemicals generated by said phase of treating the liquid accumulated in said collection tank, so that they can be at least partially reused in the said process tanning or in a subsequent tanning process. Additional features and benefits will be revealed more from the description of a form of execution preferred, but not exclusive, of a tanning process according to the invention, illustrated for illustrative and non-limiting purposes in the attached drawings where: Figure 1 is a schematic representation of the phases of an embodiment of the tanning process according to the present invention; Figure 2 is a schematic representation of a possible machine to perform the tanning process according to the present invention. With reference to the above figures, a description is given 100% tanning process with recovery of water and chemicals, hereinafter also only tanning process, according to this Z205479 -7- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl invention. Conveniently, the 100 tanning process is implemented using, for example, a machine 1 illustrated in figure 2 which shows a possible implementation scheme. The tanning process 100 comprises a phase of inputting 110 one or more skins inside a containment chamber 2 thermally insulated from the external environment, in which temperature, humidity and quantity are constantly monitored of liquid present inside. For the purposes of this invention, the term “control” means the ability to measure and regulate temperature and / or humidity and / or quantity of liquid present in the containment chamber 2 by acting on the relevant parameters. For example, in the production version of machine 1 schematized in figure 2, the containment chamber 2 is defined by an insulating casing 3, rotating around its own axis, inside which is placed a perforated wall 4 configured in such a way as to delimit a zone 5 intended for to receive the skins inside. Conveniently, the casing insulator 3 is equipped with a closable loading / unloading opening selectively sealed, by means of a lid; the wall perforated 4, on the other hand, has openings configured to allow the passage of air and liquids. The insulated casing 3 is associated with an air handling unit 6 served by means hardware and software, which are configured to generate and maintain Z205479 -8- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl inside the containment chamber 2 a temperature and / or an optimal humidity and / or quantity of water for the execution of the tanning process 100. Returning to the tanning process 100, it also includes a phase of treating 120 skins feeding to the chamber containment 2 a treatment liquid, which can be consisting of water or a mixture thereof with one or more products chemicals suitable for giving these leathers their mechanical properties, desired physical and aesthetic results. Please note that the amount of water and / or chemicals used during the treatment phase 120 the skins can vary in function of different aspects; however, this quantity, although being enough to completely wet the skins, but still remains contained within particularly low values ​​compared to the known technique. In in particular, in the tanning process 100 a quantity of water less than 200% by weight of the skins, and a amount of chemicals reduced to approximately 30% by weight, with reference to the weight of the skins, compared to the prior art. Conveniently, the treatment liquid is fed to the containment chamber 2 in nebulized form, for example by means of supply 7 provided with nozzles or other devices capable of dispensing such liquid in the form of tiny drops or aerosols, so as to allow and promote a uniform and cohesive absorption by the skin. This solution allows you to avoid immersing the skins in baths of Z205479 -9- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl treatment, as instead occurs in conventional procedures, further reducing the use of water and products chemicals compared to the known art. By way of example only, various embodiments of the tanning process 100 provide that the chemical products used in the treatment phase 120 the skins come from the group that includes deliming agents, macerating agents, agents pickling agents, tanning agents, cross-linking agents, agents soaking agents, degreasing agents, retanning agents, agents neutralizers, coloring agents and fattening agents. Note that in the execution of the tanning process 100, the treatment phase 120 skins can be repeated a number of times sufficient to obtain the desired result, and each a different treatment liquid can be used at times depending on the type of work to be done. For example, according to one embodiment where the tanning process according to the invention is used for carry out a tanning of the hides, the phase of treating 120 hides it is performed for the first time - taking the name of washing - using clean water as the treatment liquid, which is sprayed on the skins in quantities up to 100% of their weight, in order to eliminate any impurities and residues present. After washing, the phase of treating 120 skins it is repeated - taking the name of deliming - by sprinkling the skins with deliming agents which serve to free them from Z205479 -10- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl products used during calcination. After deliming, the phase of treating 120 skins is repeated again - taking the name of maceration - sprinkling the skins with macerating agents suitable for eliminating the keratin degradation products, hair residues and epidermis. Following maceration, the phase of treating 120 skins it is repeated once again – taking the name of rewashing - using only clean water as the treatment liquid, which It is sprayed on the skin in quantities up to 100% of their weight, in order to eliminate any impurities and residues present. Once the skins have been washed again, the treatment phase 120 the skins is repeated for the umpteenth time – taking the name of “pickling” – sprinkling the skins with pickling agents, that is acidifying agents that have the task of bringing the skins to a optimal pH value for penetration and fixation in dermis fibers of the tanning agents used subsequently. At this point, the phase of treating 120 skins is repeated once again – taking the name of tanning – by sprinkling the hides with tanning agents that are fixed irreversibly to skin proteins, in order to block any possibility of attack by microorganisms. Once the hides have been tanned, the phase of treating 120 skins is repeated again – taking the cross-linking name – sprinkling the skins with cross-linking agents Z205479 -11- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl which fix the tanning agents permanently on the hides. Please note that the phases described above can follow one another even in a different order, or some phases indicated as separate ones can in practice be merged together or repeated several times. For further example, in accordance with a further form of embodiment in which the tanning process according to the invention It is used to retanning the hides, the phase of treating the skins is done a first time - taking the name for wetting – spraying clean water on the skins. After wetting, the phase of treating 120 skins it is repeated – taking the name of regreening – by sprinkling the skins with greening and degreasing agents, for the purpose of free them from the coarsest dirt. The phase of treating 120 skins is then repeated again once – taking the name of retanning – sprinkling the skins with retanning agents that have the function of improving them aesthetics, filling the empty spaces, so as to to give them the desired fullness and compactness. Next, the phase of treating 120 skins is repeated again – taking the name of neutralization – by sprinkling the skins with neutralizing agents that have the task to bring the skin to an optimal pH value for the penetration and fixation of the chemical agents used subsequently. Z205479 -12- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl At this point, the phase of treating 120 skins is repeated – taking the name of tincture – sprinkling the skins with coloring agents. The phase of treating 120 skins is then repeated again once – taking the name of greasing – sprinkling the leathers with fattening agents that essentially “lubricate” their internal fibrous structure, giving them particular organoleptic properties. Consider that, even in this case, the above phases described can also follow one another in a different order, or some phases indicated as separate can in practice be grouped together or repeated several times. The tanning process 100 then includes an extraction phase 130 skins from containment chamber 2. Next, the skins are usually spread out on appropriate supports, before tackling subsequent actions mechanical, such as splitting and shaving. According to the present invention, the tanning process 100 provides that after the 120 treatment phase the skins a rinse procedure 200 is performed. Conveniently, the 200 rinse procedure is implemented using appropriate rinsing means 8. The rinsing procedure 200 comprises a draining step 210 the treatment liquid not absorbed by the skin from containment chamber 2, for example, by means of a pump. Z205479 -13- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl The rinsing procedure 200 also includes a phase of accumulate 220 the treatment liquid not absorbed by the skins, and drained from the containment chamber 2, into a collection tank 9. If necessary, the rinsing procedure 200 also includes a step of separating 215 a liquid fraction of the liquid of treatment not absorbed by the skin from a solid fraction consisting, for example, of particulates or other suspended solids. The rinsing procedure 200 therefore comprises a phase of rinse 230 the containment chamber 2 and the means of 7 treatment liquid supply, feeding them a rinsing liquid which may consist of water or a its mixture with one or more cleaning products appropriate for the scope. Conveniently, the rinsing liquid is fed to the containment chamber 2 in nebulized form, for example for by means of the same means of supply 7 of the liquid treatment, so that they too are rinsed. Subsequently, the rinsing procedure 200 comprises a phase of discharging contaminated rinsing liquid after 240 use from containment chamber 2 and a phase of accumulating 250 this liquid in the collection tank 9. If necessary, the rinsing procedure 200 also includes a step of separating 245 a liquid fraction of the liquid of rinse contaminated after use by a solid fraction. Z205479 -14- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl The rinsing procedure 200 also includes a phase of treat 260 the liquid accumulated in the collection tank 9, in in a way that separates the water from the chemicals. By way of example only, various embodiments of the rinsing procedure 200 provide that the treatment phase 260 the liquid accumulated in the collection tank 9 is implemented, for example, through a filtration process (ultrafiltration / nanofiltration, reverse osmosis, etc.) or with an evaporation process, or with other techniques of note separation. If necessary, the rinsing procedure 200 also includes a step of adding 255 one or more additives to the liquid accumulated in the collection tank 9, prior to the phase to treat 260 such liquid. By way of example only, various embodiments of the rinsing procedure 200 provide that the additives used come from the group that includes agents stabilizers, antifoaming agents, preservatives, agents heat stabilizers, antiscalant agents and regulating agents pH. The rinsing procedure 200 also includes a phase of recover 270 water and chemicals generated by the phase of treat 260 the liquid accumulated in the collection tank 9, in in such a way that they can be at least partially reused in the tanning process 100 or in a subsequent tanning process. Z205479 -15- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl Note that the amount of water and chemicals generated from the phase of treating 260 the liquid accumulated in the tank of collection 9 is close to 100% of the amount of liquid in it content. The rinsing procedure 200 also includes a phase of dispose of 280, through the planned disposal cycle, the solid fractions generated by the filtering phase 215 the liquid of treatment not absorbed by the skin and the filtering phase 245 the rinsing liquid contaminated after use. Note that, if in the execution of the tanning process 100, the phase of treating 120 skins is repeated several times using a treatment liquid other than the treatment liquid treatment used previously, it is preceded by each time from the rinsing procedure 200, so as to avoid that cross contamination occurs. In practice it has been found that the invention achieves the task and the objectives set having made available a substantially closed-loop tanning process, which allows to minimize the use of new resources and maximize recovery of water and chemicals, making them significantly more sustainable leather processing operations. In fact, as we have seen, the tanning process according to the invention allows to recover almost all the water and chemicals used, reducing the amount of non-reusable chemical waste and contaminated water. Z205479 -16- INTERNATIONAL PATENTS Ingg. Zini, Maranesi & C. srl The tanning process according to the invention also allows to significantly reduce the amount of water discharged to be purified. All this leads not only to significant savings in terms of economical, but at the same time allows you to safeguard the environment and the health of the workforce. The tanning process with water and product recovery chemicals according to the invention are susceptible to numerous modifications and variants, all falling within the scope of the inventive concept; furthermore, all details can be replaced by elements technically equivalent. Of course, the materials used, as well as the dimensions and the shapes can be any according to the needs and the state of the technique. p. RENBERTECH SRL The Mandatory Dr. Eng. F. Tamion

Claims

CLAIMS 1. Tanning process (100) with recovery of water and chemicals comprising at least the steps of: - introducing (H0) one or more hides into a containment chamber (2) thermally insulated from the outside, in which the temperature, humidity and quantity of liquid present inside are constantly monitored; - treating (120) said hides by feeding said containment chamber (2) a treatment liquid in nebulised form chosen from the group comprising water or a mixture thereof with one or more chemical products suitable for giving said hides the desired mechanical, physical and aesthetic properties; - extracting (130) said hides from said containment chamber (2); characterised in that, subsequently to said phase of treating (120) said hides, a rinsing procedure (200) is included comprising at least the steps of: - discharging (210) the treatment liquid not absorbed by said hides from said containment chamber (2);- accumulating (220) said treatment liquid not absorbed by said hides in a collection tank (9); - rinsing (230) said containment chamber (2), by feeding to said containment chamber (2) a rinsing liquid chosen from the group comprising water or a mixture thereof with one or more detergent products; - discharging (240) the contaminated rinsing liquid after use from said containment chamber (2); - accumulating (250) said contaminated rinsing liquid after use in said collection tank (9); - treating (260) the liquid accumulated in said collection tank (9), in such a way as to separate the water from the chemical products;- recovering (270) said water and said chemical products generated by said phase of treating (260) the liquid accumulated in said collection tank (9), in such a way that they can be at least partially reused in said tanning process (100) or in a subsequent tanning process.; 2. Tanning process (100), according to the previous claim, characterised in that said step of treating (260) the liquid accumulated in said collection tank (9) is carried out with a method selected from the group comprising filtration, evaporation or centrifugation.

3. Tanning process (100), according to one or more of the preceding claims, characterised in that, subsequently to said step of discharging (210) the treatment liquid not absorbed by said hides from said containment chamber (2), a step of separating (215) a liquid fraction of said treatment liquid not absorbed by said hides from a solid fraction is included.

4. Tanning process (100), according to one or more of the preceding claims, characterised in that, subsequent to said step of discharging (240) the contaminated rinsing liquid after use from said containment chamber (2), a step of separating (245) a liquid fraction of said contaminated rinsing liquid after use from a solid fraction is included.

5. Tanning process (100), according to one or more of the preceding claims, characterised in that, subsequently to said step of separating (215) a liquid fraction of said treatment liquid not absorbed by said hides from a solid fraction and to said step of separating (245) a liquid fraction of said rinsing liquid contaminated after use from a solid fraction, a step of disposing of (280) said solid fractions is included.

6. Tanning process (100), according to one or more of the preceding claims, characterised in that, preliminarily to said step of treating (260) the liquid accumulated in said collection tank (9), a step of adding (255) one or more additives to said liquid accumulated in said collection tank (9) is included.

7. Tanning process (100), according to one or more of the preceding claims, characterised in that said additives are selected from the group comprising stabilising agents, antifoaming agents, preservative agents, thermal stabilising agents, antiscaling agents and pH regulating agents.

8. Tanning process (100), according to one or more of the preceding claims, characterised in that said phase of treating (120) said hides is repeated a predetermined number of times.

9. Tanning process (100), according to one or more of the preceding claims, characterised in that, if said step of treating (120) said hides is repeated using a treatment liquid different from the treatment liquid used previously, said step of treating (120) said hides is preceded by said rinsing procedure (200), in such a way as to avoid cross contamination from occurring.

10. Tanning process (100), according to one or more of the preceding claims, characterised in that said chemical products are selected from the group comprising deliming agents, macerating agents, pickling agents, tanning agents, cross-linking agents, soaking agents, degreasing agents, retanning agents, neutralising agents, colouring agents, fattening agents.

11. Tanning process (100), according to one or more of the preceding claims, characterised in that the quantity of treatment liquid fed to said containment chamber (2) in said phase of treating (120) said hides is less than 200% of the weight of said hides. INTERNAZIONAt&BREVETTI Ingg. ZinpMàran^sp& C. srl Z205479 12. Tanning process (100), according to one or more of the preceding claims, characterised in that the quantity of water and chemical products generated by said phase of treating (260) the liquid accumulated in said collection tank (9) is close to 100% of the quantity of liquid accumulated in said collection tank (9).