MX2011009913A - Process for the manufacture of a material for absorbing dioxide carbon with a heat indicator. - Google Patents

Abstract

Process for manufacturing a material for absorbing CO2 with a heat indicator, which is formed by water obtained from a treatment plant, calcium hydroxide, calcium chloride and a hardening agent based on calcium carbonate, calcium sulphate and kaolin, which results in a white granular product with particles of 4mm of thickness, which upon reaching the balance point in the acid-base reaction said granular product is turned into a blue-violet colour with the addition of the violet ethyl indicator.

Description

PROCESS FOR THE MANUFACTURE OF AN ABSORBENT CARBON DIOXIDE MATERIAL WITH COLOR INDICATOR OBJECT OF THE INVENTION Describe a process for the manufacture of a carbon dioxide absorbent material (COj) with color indicator, which is made by means of Calcium Hydroxide (Ca (OH)), Calcium Chloride as a humectant and a hardener from a mixture of Calcium Carbonate, Calcium Sulphate and Kaolin. The main characteristic of this product is the improvement in the selection of the materials to elaborate it since they avoid corrosion, irritability and toxicity, in addition to using a color indicator to make the equilibrium point of the acid - base reaction noticeable when This is saturated with Carbon Dioxide. The dry material serves as an adjunct to artificial respirators in hospitals to prevent patients in whom it is necessary from becoming poisoned with the carbon dioxide released during exhalation.

BACKGROUND OF THE INVENTION Throughout time, there have always been people with the need to use a respirator, whether due to accidents, illnesses or the effects of anesthesia in operations. This is why doctors and researchers felt the need to create materials that could absorb carbon dioxide (C02) that was released by patients during assisted breathing, to prevent them from becoming poisoned with these gases released during exhalation.

The use of this type of C02 absorbent materials for the breathing circuits that were given, had its beginnings in 1914 when the pharmacologist Dennis Jackson applied the soda lime as a reaction material in contact with the Carbon Dioxide, to make possible the re inhalation free of toxic gases and thus prevent the C02 circulate again by the gas flow to the patient. This method was far from what was expected because in its application presented various complications in patients as the increase in the temperature of soda lime by absorbing C02.

Over the years the soda lime was modified, in a search to improve its absorbent properties and to avoid the disadvantages of practical use. For this, mixtures of alkali and alkaline earth metal oxides and hydroxides were added to the soda lime being the most used: sodium, calcium, potassium and some others.

One of the methods explained in the U.S. Pat. No, 3,847,837, describes a C02 absorbent prepared from metal hydroxides such as barium, calcium, lithium, sodium and mixtures between them, as well as including a non-hygroscopic inorganic component that prevents the accumulation of dust on the surface of the granules and protects its porosity, and that is mainly made up of metal oxides such as Zinc Oxide, Titanium Dioxide and Nickel Oxide, which make up 5-10% by weight of the total composition of the granules. This invention was to modify the typical composition of soda lime including other metal hydroxides, in addition to adding a hardener component of the product to stop the formation of dust and protect its granules.

The U.S. Pat. No, 7,727,309 B2 describes the invention of a C02 absorbent with a content between 70-90% of Calcium Hydroxide, 0.1 - 17% of Lithium Hydroxide and of 5 - 25% of water, as well as 0.1 - 10% % of hardening agents, indicators and humectants. In this patent the benefit is observed that people in assisted breathing only have contact with a small part of the Nephrotoxic Olefin (Compound A), as well as that they generate a by-product and have a high degree of absorbency.

In the U.S. Pat. No, 4,407,723 explains the invention of an absorbent based on metal hydroxides of group I or II and between 2 - 3% of Sodium Hydroxide as an additive, as well as between 1 - 2% of Potassium Hydroxide and 0.1 - 1% of Calcium Chloride, sprayed on the surface of the already dry granules.

For the cases of the last two patents there are numerous studies that talk about the reaction of soda lime with anesthetic agents such as Isoflurane, Sevoflurane, Desflurane and Enflurane producing highly toxic substances, among which Carbon Monoxide (CO), that can produce hypoxia and coagulation problems, and Nephrotoxic Olefin (CF2 = C (CF3) OCH2F) and that can be lethal at a consumption of between 350 - 400 ppm. Both substances are mostly produced by catalytic materials such as Potassium Hydroxide, Sodium Hydroxide, Barium Hydroxide and Lithium Hydroxide that have between 4 - 20% of the total composition of the product.

Another of the patents that describe a C02 absorbent is U.S. Pat. 3,489,693 where it contains 60-95% Magnesium Oxide and 5-40% Lithium Hydroxide monohydrate, as well as between 85-90% Magnesium Hydroxide and 10-15% Lithium Hydroxide Monohydrate and because the drying of the material is at 150 ° C, it is practically absent of water. The disadvantage with this type of methods is the dehydration of the material, which raises the temperature, the absorption of the halogenated anesthetic granules, as well as the metabolic degradation thereof, which can form toxic compounds such as Compound A and Carbon Monoxide, if the anesthetic is Sevoflurane, which is metabolized faster with a degraded percentage of 6.5% at 22? C and with an increase of 1.6% per hour. On the other hand, in research in this regard it could be demonstrated that with the addition of 10-30% of water favors to avoid dehydration of the product as well as the formation of toxic compounds.

It has been shown that the simpler the composition of the absorbent and the smaller the number of components, the product will be safer and more functional, and the elimination of Sodium and Potassium Hydroxides will reduce the degradation of analgesics. the absorption of C02 is affected. An example of this is what is described in the U.S. Pat. No. 6,288,150 Bl describing the invention of an absorbent based on Calcium Hydroxide, 17.5-30% of Water, approximately 10% of a hygroscopic or deliquescent inorganic wetting agent or a Dihydroxylated or Polyhydroxylated organic wetting agent, 4.5-5% of Calcium sulphate as a hardener and 0.5 - 1% metallic aluminum to aerate the granules.

The application of the U.S. Pat. No, 2004/0029730 Al is one that most closely resembles the process that will be described in this patent as it describes the invention of a C02 absorbent with 75 - 85% Calcium Hydroxide, 0-1 - 5% Calcium Chloride or Magnesium, 0.1 - 5% hardening agent such as Aluminosilicates, 0.1 - 5% bonding agents and plasticizers derived from celluloses or gums and 12-25% water as well as minor components such as indicators and anionic detergents.

The following table shows some of the main absorbents of C02 that are marketed and includes the additives that have been included in their formulas throughout the development of these products. The amounts are presented in percentages.

DESCRIPTION OF THE FIGURES Figure 1 is a process diagram showing the steps of preparing the granular absorbent material of CO2 with color indicator, and describing it by means of each unit operation to which it is subjected.

DETAILED DESCRIPTION OF THE PROCESS The characteristic details of the process for the manufacture of the carbon dioxide absorbent (C02) with indicator from the Calcium Hydroxide and having a hardening agent and humectant are shown in detail in the following description.

According to what has been researched in other patents and sources, the other methods of carbon dioxide absorbers (C02) are not very efficient, since the components that make them can be toxic and harmful to health. Due to the need to create a C02 absorbent material that is free of Potassium Hydroxide and Sodium Hydroxide and that is also stable in the presence of common anesthetic agents, the following process has been developed that obtains a material with a content of 50 - 80 % of Calcium Hydroxide, 20 - 35% Water, 0.1 - 5% Anhydrous Calcium Chloride as humectant, 0.5 - 1.5% Ethyl-violet indicator, 1-10% Hardener, which is the result of a mixture of 50 - 65 % of Calcium Carbonate, 15 - 20% of Calcium Sulphate and 15 - 20% of Kaolin; obtaining as a result a white granular product with a size of approximately 4 mm, which upon reaching the equilibrium point of the acid-base reaction changes its coloration to violet blue.

In order to obtain this C02 absorbent with indicator, we have a process which is divided into different stages.

The first stage is the mixing where between a mixer mixer with a capacity between 450-500 kg and a speed in the stirrer between 50 - 100 rpm are introduced between 150 - 180 L of water, which can come from a treatment plant of waters. The mixer is turned on at a speed of approximately 60 rpm and 10-15 grams of the Violet Etil indicator is added until the water turns dark purple. Once the mixer already contains the water with the color indicator, it is necessary to add 95% Calcium Hydroxide in batches of 25 kg until adding between 250 - 300 kg of it. While the Calcium Hydroxide is mixed with the water, it is necessary to add the wetting agent which in this case corresponds to add between 4 - 5 kg of Calcium Chloride. Finally it is necessary to add a hardening agent so that the granules can be formed, this is made of a mixture of between 12 - 16 kg of Calcium Carbonate, 3.5 - 5 kg of Calcium Sulphate, and also between 3.5 - 5 kg of Kaolin. The materials are kept mixing for a period of 30 - 45 minutes at ambient temperature and pressure.

For stage two of the process it is necessary to discharge the mixer by means of the discharge valve of the same. The discharge is done with the mixer turned on at a speed of 60 rpm approximately so that the product comes out complete with the help of the movement of the pallets. The mixture is placed in stainless steel trays or trays and the mixer is turned off.

From here we go to stage three of the process, which is drying, in this case the mixture placed in stainless steel trays is introduced into the vacuum dryer of carbon steel dividing plates. The filled trays are placed on the dividing plates and the doors are completely closed to create a vacuum of around 25 inches of Hg. Once the dryer is hermetically sealed, it must be checked that the boiler is switched on to proceed to open the drying steam valve that feeds the dryer. After this the water purge valve is opened for the necessary time until steam starts to appear instead of leaving water and must be closed. The drying steam line must have a regulator so that it does not enter the dryer with a pressure greater than 1 kg. The temperature to carry out this drying should be between 70 - 80 5C, preferably at an average point of 75 - C and so dry the material for an estimated time of 1.5 - 2 hours. When this time passes, the vacuum pump should be turned on for 30 - 45 minutes at a pressure of 25 inches of Hg to release the moisture accumulated in the dryer. Once the temperature inside the dryer drops and you have an ambient temperature, which can be observed by means of a temperature gauge, the dryer doors are opened and the trays are removed with the dry material.

This gives way to the fourth and final stage of the process, which is the grinding and screening of the material. In this case the material is emptied in a stainless steel roller mill with a speed of between 50 - 100 rpm with meshes of between 4 - 8 mm to obtain irregular granules and powder. After this the material is passed to a vibrating screen of 8 mm per square inch with a screening speed of around 900 rpm so that only the granules remain dust-free and these are passed to a tank. The material of these tanks must be re-routed through a roller mill and then screened with 4 mm per square inch mesh. The material that remains above the 4 mm meshes is the one that must be packaged by means of a hopper so that it can be sold in the medical industry.

The following examples are based on the different types of drying that were used in the mixture to achieve that the material had the shape and consistency that is necessary for respiratory assistance during anesthesia. For all these examples, the same formulation was used in the content.

Example 1 For this example 180 L of water from a treatment plant were used, which were deposited in a mixer under the following conditions: v = 60 rpm T = 25? C The water began to mix together with 12.5 grams of Etil Violeta until the water changed its color to a dark purple. At the time of the vire, 250 kg of Calcium Hydroxide were added in batches of 25 kg and agitation was continued until the mixture was homogenized. After continuing with the agitation, 5 kg of Calcium Chloride was added, as well as the hardener of the mixture, which consisted of a mixture of 14 kg of Calcium Carbonate, 4.5 kg of Calcium Sulphate and 4 kg of Kaolin. The mixture continued to be mixed under the following conditions: Time: 40 minutes T = 25 2C P = environmental At the end of the mixing time the lit blender material was extracted, which helped the material to come out and be deposited in stainless steel carts. All under the following conditions: V = 60 rpm T = 25 5C ? = environmental This mixture was placed in trays which were placed on a direct fire for drying. Here we could observe that this type of drying did not work since the material changed its color to purple instead of remaining white, due to the contact of the material with the air and the C02 saturation that it obtained. The remainder of the process has not been continued.

Example 2 For this example, the same conditions as in Example 1 were used, but in this case a hot air dryer was used under the following conditions: T = 80 2C P = environmental Time: 1 hour At the end of the drying it was observed that the material had turned purple to purple because it continued to have contact with air, so that the material was no longer passed to the grinding and screening stage.

Example 3 In this example the same components and conditions as Example 1 were used but in this case the product was dried with a gas oven under the following conditions: T = 130 Time: 40 min This type of drying did not work either because the material being in contact with the high temperatures changed the color to purple equally, this is given from a range of 120-150 Example 4 In Example 4 the same conditions as in Example 1 and in the description of the process of this patent were used. Here it was concluded that the method that would work for the drying of the material and that did not affect the change of coloration of the same would be that it would have to be done with a vacuum dryer under the following conditions: T = 75 2C Internal vapor pressure = 1 kg Time = 1.5 hr After this time, the drying steam was closed and the vacuum pump was switched on at a pressure of 25 mm Hg. In this way, the product can be released and passed to the grinding stage by placing the material in a stainless steel roller mill under the following conditions: v = 70 rpm T = 25 5C The material passed through different meshes of between 4 and 8 mm until irregular granules and dust remained. After that material was passed to a vibrating screen with an 8 mm mesh where at a v = 900 rpm the dust was removed from the granules that were transferred to a tank. After these same granules were screened again with a mesh of 4 mm and thus the desired material was obtained which was packaged.

Claims (4)

CLAIMS Having sufficiently described my invention, I consider it a novelty and therefore I claim my exclusive property, contained in the following clauses:

1. Carbon Dioxide absorbent material with color indicator characterized because it is comprised of the following materials: a) Water from a treatment plant, b) Violet Etil indicator, c) Calcium hydroxide, d) Calcium chloride, and ) Hardener agent based on a mixture of Calcium Carbonate, Calcium Sulphate and Kaolin.

2. Carbon Dioxide absorbent material with color indicator that based on Claim 1 is comprised of the following ranges of materials: a) Add between 150 - 180L of water from a treatment plant to a mixer, b) Add between 10 - 15 grams of Indicator Violet Etil to water, c) Add between 250 - 300 kg of Calcium Hydroxide to 95%, d) Put between 4 - 5 kg of Calcium Chloride to water, e) Add the hardening agent with a mixture of between 12 - 16 kg of Calcium Carbonate, 3.5 - 5 kg of Calcium Sulphate and 3.5 - 5 kg of Kaolin.

3. Carbon Dioxide Absorbent Material manufacturing process with color indicator characterized by having the following stages of execution: a) Mixing of Materials, b) Unloading material from the mixer, c) Drying the mixture and, d ) Grinding and screening of material.

4. Manufacturing process of the Carbon Dioxide Absorbent material with color indicator that according to Claim 2 has the following stages and conditions: a) Mixing of materials in a kneader mixer of capacity of 450-500 kg with stirring speed of between 50 - 100 rpm, b) Discharge of the mixer material with a preferential speed of 60 rpm so that all the material comes out of it, c) Drying of the mixture in a vacuum dryer of dividing plates and steel coal with a vacuum of 25 inches of Hg, steam at a pressure not greater than 1 kg temperature between 70 - 80 2C, drying time of between 1.5 - 2 hours, use of vacuum pump for a time of between 30 - 45 minutes , d) Grinding and screening of material first with a stainless steel roller mill with speeds between 50 - 100 rpm and meshes of between 4 - 8 mm, then go through an 8 mm mesh vibrating screen for dust removal and after vol see to pass in 4 mm vibrating screen to obtain the final product. Manufacturing process of Carbon Dioxide Absorbent material with color indicator according to claim 2 uses a vacuum dryer of dividing plates and carbon steel with a vacuum of 25 inches of Hg, steam at a pressure no greater of 1 kg, temperature between 70 - 80 ° C, preferably 75 ° C and a drying time of between 1.5 - 2 hours. Manufacturing process of Carbon Dioxide Absorbent Material with color indicator that according to Claim 2, granules of about 4 mm thickness must be obtained for its use. SUMMARY OF THE INVENTION Process for the manufacture of a C02 absorbent material with color indicator, which is formed from water that comes from a treatment plant, Calcium Hydroxide, Calcium Chloride and a hardening agent based on Calcium Carbonate, Sulphate Calcium and Kaolin, and which results in a white granular product with 4 mm thick particles when it reaches its equilibrium point of acid - base reaction changes its coloration to blue - violet due to the addition of the indicator Violet ETHELY on it.