There is no process similar to the object of the present patent available in the scientific literature and in patent applications, nor in the market, that can via the use of water capture all of the O2 from the processed air and produce oxidizing gases with varied content of O2 and N2 with a purity level between 95% and 98%, and, optionally, fully deaerated water.
This report presents, separately, the States of the Art regarding each one of the fields to which the object of the present patent is related, plus some pertinent criticism.
A—O2 and N2 production
B—deaerated water production
C—process through which liquid food may be cold-sterilized by insufflating high pressure N2 followed by decompression.
The first two fields relate to very early processes that are now all in the Public Domain, whose objectives relate to those of the object of the present invention. The last field—cold sterilization of liquids—introduced quite recently and, therefore, not widely known, will be presented in detail later on in this Patent Report. Its process uses in its forms, values, and different objectives, the gasification and degasification of liquids under high pressure variation of process gases, with fixed and pre-determined temperatures, as it will be presented in detail later on in this Patent Report.
State of the Art for the Production of Both Nitrogen and Oxygen
Nearly 100% of O2 and N2 are produced simultaneously using the same piece of equipment, in liquid form, through the century-old cryogenic process.
There is only one alternative technology to cryogenics for the production of O2 and it's applied to local production, using two different pieces of equipment that supply only gaseous O2—as no N2 is produced—to hospitals and some industries.
This technology—introduced back in the 1960s—separates O2 from the air by filtrating the air through artificial or natural membranes such as zeolitic rocks.
These processes are called ‘Pressure Swing Adsorption (PSA)’ and ‘Vacuum Pressure Swing Adsorption (VPSA)’, which are an improvement of the first type of equipment, both using molecular screens for pressing the atmosphere air, without moisture and particulate, between 3 and 6 bar, thereby causing the screens to retain N2, methane, carbon monoxide, and dioxide, but releasing O2. Following this part of the operational cycle, the membranes are cleaned up by releasing the retained gases back into the atmosphere, at which point the second half of the cycle, adsorption, is initiated.
The State of the Art for Water Deaeration
This is considered a century-old process for the removal of O2 from water intended to be used in the food industry or in boilers as a way to avoid the oxidation of food or piping.
Water deaeration is regarded as a simple technique. The water is heated up to its boiling point and then taken to the deaeration tank where it loses its dissolved gases and becomes O2-free. The two major gases that make up the air, which are extracted by deaeration, are simply released together into the atmosphere as they are not considered valuable by-products from the process, given that the small quantity of such gases dissolved in the water at ambient pressure and temperature—8.9 mg O2 and 13.8 mg N2 per liter of water—is regarded as a by-product that has no value both ecologically and economically.
The State of the Art for the Cold-Sterilization of Liquid Food by Insufflating High-Pressure N2 Followed by Decompression
The process described by Patent PCT/BR2014/000295, “PROCESS AND EQUIPMENT TO INCREASE THE STORAGE TIME OF LIQUID RAW FOOD”, filed with PCT on Aug. 25, 2014 and numbered PCT/BR2014/000295, examined by the “Written Opinion of the International Searching Authority” and published on Mar. 25, 2015 as a total “Novelty”, an “Inventive Step”, and of “Industrial Application” may be regarded as the State of the Art in the new technological area inaugurated by said patent.
This PCT/BR2014/000295 employs pressure differential in the process, but not temperature differential. Furthermore, the gases that are compressed on the liquid are other than the air and are intended for the cold-sterilization of liquid food by the explosion of the cells of contaminating microorganisms, with said liquid food being previously subjected to N2 insufflation with up to 10% CO2, under fixed and invariable temperatures along the process, ranging from 6° C. to 50° C., under pressures raging from 25 to 50 MPa, being subsequently directed to a decompression vessel, under as low a pressure as up to 0.2 bar, leading to a suddenly immediate and large expansion of insufflated gases, which characterizes a deadly explosion of the cells of contaminating microorganisms.
Comments on the State of the Art
The process hereby disclosed is totally different from the description provided by current processes and, particularly, by the process described in Patent PCT/BR2014/000295, given that:
A—in the process, object of the present patent application, the water is gasified with atmospheric air, with maximum economic gasification pressure at 3.1 MPa (±5%) provided the temperature is at 25° C. During the process phases, the temperature of fluids (water and gas) may vary from 0° C. to ambient temperature in the water gasification phase, and gasification may be carried out under ambient temperature up to 85° C.
B—in the process, object of the present patent application, the water may be only the process fluid or else the product, such as the gases of the air extracted from the atmosphere, separated and used, while in PCT/BR2014/000295 patent, the fluids used in the process are the liquid food, N2 and CO2, and the temperatures under which the process is conducted are invariable along the process, ranging from 6° C. to 50° C., while pressures range from 25 MPa to 50 MPa, and the only products are the liquid food.
C—as a result of the aforementioned differences relative to the temperatures and pressures of both processes and due to the required embodiment of the pieces of equipment for the intended purpose of each one of these two patents, it's obvious that the pieces of equipment described herein and those described in Patent PCT/BR2014/000295 cannot be used interchangeably, that is, one cannot carry out the same tasks of the other as the high process pressures in the aforementioned PCT, ranging from 25 MPa to 50 MPa, would solubilize all the air volume being compressed on the water, thereby destroying the interface between these two fluids, and creating a single liquid phase in such an extremely critical situation that upon being undone during the deaeration process, it would rebuild the air as it is found in nature and would not be capable of breaking down the air into its main components, nor generate the products object of the present patent.
D—Both the process and the pieces of equipment object of the present patent are not reciprocally capable of sterilizing liquid food, given that the low pressure in their process—maximum 31 atm. or 3.1 (±5%) MPa—is not capable enough to insufflate gases in the necessary amount and at the required pressure to carry out the sterilization through explosion of the microorganisms, as is the case of Patent PCT/BR2014/000295, which requires a pressure between 25 MPa and 50 MPa.
Advancements of the Present Invention in Relation to the State of the Art
The fundamental differences between the present Patent and the State of the Art are as follows:
1st—according to the present patent, the water that will be deaerated is previously aerated at a given pressure only enough to dissolve all the volume of O2 in the air that is compressed upon it, along with the portion of N2 of the air, whose capture cannot be dissociated from the process. Afterwards, part of the air, under an opposite temperature at which the process is carried out, is recovered at the top of the deaeration tank, in the form of oxidizing gas, containing 39% O2 and 61% N2 by weight, with N2, which was originally part of the compressed air and was not solubilized in the water, being collected at the top of the aeration or gasification tank showing a purity level between 95% and 98%.
2nd—unlike the State of the Art, which mandatorily requires high water temperature, up to its boiling point, the process degasification, object of the present invention, may be conducted by the preferred embodiment of its pieces of equipment simply by reducing degasification pressure in the degasification tank down to a little bit less than the atmospheric pressure to obtain the same oxidizing gas, and, following degasification, the process water keeps about 20 mg of air, per liter of water, dissolved in itself and, therefore, cannot be used as totally deaerated water.
3—degasification may also be carried out by equipment as formed in the first construction variant of the object of this patent by reducing pressure and, at the same time, increasing the temperature, or sending it to equipment that is found in certain industries, which is used to fully deaerate water and, in these cases, produce the oxidizing gas and fully deaerated water.
The preferred embodiment of the object of this patent, for the recirculating process water at ambient temperature, carries out the local production of oxidizing gas with 39% O2 and 61% N2 by weight and N2 at levels between 95% and 98% with a single processing and the local production of oxidizing and industrial gases with higher O2 content 39% by weight, through reprocessing the gases obtained in previous processing.
The construction variant of the object of this patent carries out the gasification of air at 0° C., full deaeration of water at 85° C., and produces the same gases as the preferred embodiment.
Both the preferred embodiment and the construction variant that carry out the process object of this patent can be coupled by the bases of their gasification tanks to the full water deaeration equipment used in certain industries for obtaining the oxidizing gas and fully deaerated, with N2 continuing to be produced in the tops of the gasification tanks.
Uses for the oxidizing gas produced by the object of this patent include:
A—its being added to the combustion air of metallurgical, ceramic and glass furnaces, and internal combustion engines industries to protect the environment because it:
I—reduces excess air for combustion and, consequently, saves fuel,
II—reduces NOx, CO, and CO2 levels and particulates in waste gases from gas ovens, furnaces, or internal combustion engines,
III—increases the temperature of the flames, allowing biomass to be used in thermal processes and the use of fuels, such as natural gas, which burn with low temperature flames when the combustion air is not enriched by O2.
B—For every 1% increase by weight of O2 to the combustion air can result in a temperature rise of 35° C. in the natural gas flame.
C—One liter of oxidizing gas with 39% O2 by weight can be mixed to 14.7 liters of atmospheric air to increase its O2 content by 1% or mixed to 4.23 liters of atmospheric air to increase its O2 content by 3%.
D—Can be used as a local source of O2 for bleaching pulp and tile and for sewage treatment, thus preserving the decomposing aerobic flora to restore wastewater to the authorization standard for release back into natural water resources.
The embodiment of the process object of this patent just for oxidizing gas production for thermal effects, bleaching materials, and sewage treatment, if carried out using proportions of air on water greater than 1 liter of air per liter of water and at ambient temperatures, involves very low costs because it can use lower gasification pressures. In these cases, the N2 produced has a lower degree of purity, but keeps the composition of the oxidizing gas at 39% O2 by weight, being produced in smaller quantities.
The possibility of the process object of this patent being carried out at various temperatures and environmental pressures, by suitable equipment, as well as partial coupling of the equipment that embody the process to equipment designed to deaerate pre-existing water allows for optimization of economic factors, such as initial investments, operating costs, and production levels, as will be described in detail in this patent report.
Calculations and numerical values presented in this report have a degree of significance of ±5% due to the variation in experimental values, rounding off the calculations, deviations from the ideal gas, and variation of the composition and air density owing to the humidity, pressure and atmospheric temperature, and the presence of other gases in the air and refer to the proportion of one liter of air per liter of water, although the process may occur at various temperatures and proportions of these two fluids, generating easily determinable results, with 25° C. being regarded as the ambient temperature.
Scientific Basis of the Object of this Patent
The scientific basis underlying the operation of the “CONTINUOUS PROCESS AND EQUIPMENT FOR THE PRODUCTION OF OXIDIZING GAS CONTAINING 39% O2 AND 61% N2 BY WEIGHT, AND DEAERATED WATER” is that the property of the water that acts as an O2 concentrator when it dissolves the air gas, because the solubility index of O2 is greater than 1.7 times than that of N2 and all stages of the process take place according to the General Theory of Gases, Henry's Laws relating to the solubility of gases in liquids—temperature effects, total pressure and partial pressure of gas—and tables of solubility of gas in water.
For all practical purposes, O2 and N2 in the air, respectively accounts for 21% and 79% by volume and 23.3% and 76.7% by weight; however, due to the superiority of the solubility index of O2 in relation to that of N2, O2 and N2 respectively account for 39.2% and 60.8% by weight and 35.7% and 64.3% by volume on the surface layer of a freshwater lake.
At a temperature of 25° C. and 1 atmosphere pressure, one liter of water, in sufficient contact with 1 liter of air dissolves 22.7 milligrams thereof; from the total deaeration of the water thus aerated, 22.7 mg of a gas composed of 8.9 mg of O2 and 13.8 mg N2 or 39% O2 and 61% N2 by weight are obtained.
Air density is 1.180 mg per liter at one atmosphere pressure at 25° C. and is composed of 275 mg of O2 and 905 mg N2; 22.7 mg of air dissolved in water under these temperature and pressure conditions result in a solubility of air in water, in air milligrams per kilogram of water, of only 1.9% gas by weight.
Given that the amount of a gas soluble in a liquid is also directly proportional to the gas pressure exerted on it, a pressure of (1 atm/0.019)=52.7 atmospheres, 1 liter of water completely solubilizes 1 liter of air, but when removed from said pressure, the dissolved air returns to a gaseous state and returns to its form as it is in nature.
Therefore, at a temperature of 25° C., the required pressure to solubilize all the O2 in the air in order to produce an oxidizing gas, along with N2, which is indissociable from the process, has to be lower than (1180/22.7) or 52 atmospheres. In fact, at a temperature of 25° C., to capture all the O2 in one liter of air by solubilizing it within one liter of water, with a minimum quantity of N2 solubilized in said water, the pressure, not higher than the required one, and that, therefore, is capable of dissolving, concomitantly, the lower quantity of N2, is (275 mg O2/8.9 mg O2/atm)=31 atm.
The threshold pressure for carrying out the process at the most economical way, object of this patent, is always the one just enough to remove from the air all the O2 contained therein, by solubilizing the air in the water containing the least amount of N2 at that temperature.
Likewise, as for the operating temperature limits of this process, object of this patent, the minimum temperature is that at which water is still in liquid form—0° C.—and the highest, theoretical temperature for carrying out the process is one in which air solubility in water is still greater than zero, wherein the degasification step of this process can be achieved more economically if carried out at 85° C., with the internal pressure of the degasification tank at 0.5 atmospheres for the oxidizing gas, N2, and fully deaerated water to be obtained.
The solubility of a gas in water increases with decreasing temperature, in a specific, nonlinear curve; at a temperature of 0° C., at a pressure of 1 atmosphere, in liquid water, 37.2 mg of air per liter of water are dissolved—consisting of 14.6 mg O2 and 22.6 mg N2—i.e., the amount of air dissolved in water at a temperature of 0° C. is (37.2/22.7)=1.64 or 64% greater than at 25° C.
To capture all the O2 from the air at a temperature of 1° C., the operating pressure is less than the required pressure at ambient temperature, which results in economic and environmental gains. The density of one liter of air at 0° C. is 1.293 mg—consisting of 300 mg O2 and 993 mg N2. That being the case, (300 mg O2×atm/14.6 mg O2)=20.6 atm is enough to capture all of the O2.
The object of this patent makes no claims regarded the deaeration of water in the conditions of the State of the Art, and the process only refers to water deaeration of previously aerated water under pressure, with the essence of the known State of the Art being only the deaeration of the water by thermal means as if it was exposed to air in nature, without aeration under pressure.
This process allows the recovery of gases dissolved in water under pressure only by decreasing the pressure to degasify the water with the aim to produce oxidizing gas, and the process at a pressure of 31 atmospheres and temperature of 25° C., produces a ratio of 583 ml per 1,000 ml of air treated with the same volume of water and also produces 417 ml of N2 with a purity between 95% and 98%.
Process Description, Figures and Functionality of the Preferred Embodiment and the Construction Variant of the Pieces of Equipment that Carry Out the “CONTINUOUS PROCESS AND EQUIPMENT FOR THE PRODUCTION OF OXIDIZING GAS CONTAINING 39% O2 AND 61% N2 BY WEIGHT, WITH N2 HAVING A PURITY LEVEL BETWEEN 95% AND 98%”, Object of the Present Invention.
The process, object of the present invention, “CONTINUOUS PROCESS AND EQUIPMENT FOR THE PRODUCTION OF OXIDIZING GAS CONTAINING 39% O2 AND 61% N2 BY WEIGHT, WITH N2 HAVING A PURITY LEVEL BETWEEN 95% AND 98%”, is carried out by their pieces of equipment in a three-step sequence that produces an oxidizing gas of 39% O2 and 61% N2 by weight in a single process and then reprocessed by the same equipment, using the same three steps for obtaining oxidizing gases with levels greater than 39%, the production of N2 with a purity between 95% and 98%, and partial or complete deaeration of water, which can be recirculated as process fluid in the event the process be carried out completely in varying environmental temperatures to produce only the oxidizing gas and N2 and, if the third step of the process is carried out at 85° C. and a pressure of 0.5 atmospheres, deaerated water is obtained, of which only the part of its equipment that is responsible for the capture and gasification of the water and removal of the N2 may be coupled to pre-existing equipment for total water deaeration to obtain these same results with smaller investments, as follows:
1st step—gasify the water by atmospheric air compression on it at temperatures that may range from slightly above its solidification temperature and possibly lower than its boiling point, in variable pressures and just enough to solubilize in water all the O2 in the air at a temperature at which the process is carried out, between 20.6 (±5%) atmospheres at 0° C. and 31 (+/−5%) atmosphere at 25° C., as the proportions of air and water may vary, with the mixture of gasified water and the gas sent at the same gasification temperature and pressure to a gasification tank,
2nd step—maintain the pressure and temperature of the first step inside the gasification tank, while removing from its top the N2 that was not solubilized in water and separate, by draining the gasified water which accumulates at the bottom of the gasification tank, sending said water to the degasification tank, while still at this pressure and temperature,
3rd step—degasify the gasified water and separated from the gases that were on it in the second step in a degasification tank by decreasing gas pressure on it, and may or may not be an increase of the fluid temperature and then collect the oxidizing gas obtained at the top of the degasification tank, in its own gas holder, containing 39% O2 and 61% N2 by weight, and the water collected in the bottom of the degasification tank is recycled as process fluid or, in the event it is fully deaerated, depending on the temperature and pressure at which it was degasified by the equipment itself or external total water deaeration equipment, this water is also a product of the process.
The equipment used in the “CONTINUOUS PROCESS AND EQUIPMENT FOR THE PRODUCTION OF OXIDIZING GAS CONTAINING 39% O2 AND 61% N2 BY WEIGHT, WITH N2 HAVING A PURITY LEVEL BETWEEN 95% AND 98%.”—may carry it out:
A—by the preferred embodiment at ambient temperature in all the three steps described herein, for instance, at a temperature of 25° C. and pressure between 29.45 and 32.55 atmospheres, i.e., at the pressure of 31 atmospheres (±5%) in gasification to achieve a pressure that is just enough so that any O2 contained in this volume of air will be dissolved in water, with minimum simultaneous dissolution of N2, with the volumes of air and water varying at any temperature at which the process could be effected and, consequently, the pressures and the processing results varying, so that 1 liter of air per liter of water at 25° C. produces the following results:
with the water being only the process fluid, because under such temperature and pressure conditions the water cannot be fully degasified or deaerated, because the water thus processed, at the end of the third step, still contains 8.9 mg O2 and 13.8 mg N2, or 22.7 mg dissolved air therein, corresponding to 1.9% air by weight per liter of water, such as occurs naturally in water exposed to air at ambient temperature and pressure;
B—in its first construction variation in higher cost equipment with devices capable of altering the temperature of the fluid between the three processing steps which allow the gasification to be effected at a temperature of 0° C. and at a pressure of between 19.57 and 21.63 atmospheres, i.e. at a pressure of 20.6 atmospheres (±5%), both pressure and temperature being kept equal in the second step—and degasification or deaeration is performed at a temperature of 85° C. and a pressure of 0.5 atmospheres, with which it may be possible to obtain 766 mg—or 635 ml—of the oxidizing gas with 39% O2, and N2 and 61% by weight composed of 301 mg—or 229 ml—O2 and 465 mg—or 406 ml—N2 containing between 95% and 98%—values already corrected for the volumes at 25° C. with an increase of 9% in its air capture efficiency, which also allows for obtaining fully deaerated water.
Although shown only in the preferred embodiment, the construction variant may also include a gas holder, valves, and by-pass ducts to reprocess the gas obtained, as well as send the gasified water, already separated from the undissolved N2, along with O2, for gasification in external deaerators in relation to the object of this patent.
Filing Document | Filing Date | Country | Kind |
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PCT/BR2017/050029 | 2/10/2017 | WO | 00 |