EP4028149A1

EP4028149A1 - Separation of a selected gaseous component from a gas mixture

Info

Publication number: EP4028149A1
Application number: EP20862834.7A
Authority: EP
Inventors: Serhii HABROSHVILI; Mihails SOLOMKO; Reinis SPUNDE
Original assignee: Obf Tech Sia; Obf Technology Sia
Current assignee: Obf Tech Sia; Obf Technology Sia
Priority date: 2019-09-10
Filing date: 2020-09-08
Publication date: 2022-07-20
Also published as: WO2021049923A1; EP4028149A4; LV15555A; WO2021049923A9

Abstract

The invention relates to means of purifying acid pollution of gaseous fuel combustion products, in particular, from NO_x and CO₂. The claimed process for separation of a selected gaseous component from a gas mixture comprises the following steps: i) supplying an electromagnetic radiation at frequency substantially within the range of natural frequency of molecules of the gaseous component selected to be separated from the gas mixture; ii) passing a gas mixture through the created electromagnetic field; iii) further passing the gas mixture towards a membrane, having pore size adapted to allow selected gaseous component to pass through the membrane pores. The claimed device for embodiment of the process for separation comprises, in particularly, a microwave generator adapted for supplying an electromagnetic radiation and a membrane module comprising a membrane or a set of membranes, having pore size adapted to allow selected gaseous component to pass through the membrane.

Description

SEPARATION A GAS MIXTURE

Field of Invention

[001] The invention relates to means of purifying acid pollution of gaseous fuel combustion products, in particular, from NO_x or CO2. It can be used in decontamination of exhaust gases of internal combustion engines, heat and power plant furnaces, such as boilers, thermal power plants, etc.

[002] Recently, there were a lot of published research results on the elimination of nitrogen oxides and carbon oxides that negatively affect the environment, in particular the air basin of the planet. It has been proved that N2O found in the Earth's stratosphere is an essential source for NO formation, which in turn has a significant impact on the depletion of the Earth's ozone layer. Besides, N2O is considered a gas, which contributes to the greenhouse effect, with the potential of N2O in the processes of climate change (warming] being almost 290 times higher than the potential of C2O [Thiemens and Trogier, Science magazine 251, p. 932, 1991].

[003] There is known a method for processing exhaust gases with NO_x and sulfur- containing substances, as well as a device for implementing this process by their multistage irradiation with an electron beam (US 4435260]. The process provides for the addition of ammonia (NH3] to the exhaust gases before and after irradiation, and their sequential transmission through several irradiation zones and zones free from irradiation. During gas flow processing, solid products of NO_x and S with NH3 interaction get to the dust collector. Waste gases are released into the atmosphere after multi-cascade irradiation and dust separation. The device implementing this process contains a chamber with many generators that form electron beams with pre calculated technical characteristics. The disadvantage of this process of waste gases treatment is that to prevent irradiation of service personnel and production facilities, the device with its irradiation chamber must be shielded by solid protective concrete walls, in addition, the electron beam generators are quite large in size, and therefore in the automotive industry and in low-power boiler furnaces of power plants such a process cannot be used.

[004] There is also known a process of purification of waste gases, for the implementation of which reactors with a laser beam (laser A_rF with 193nm wavelength) are used, while the purification process is carried out with the introduction of methanol (CH₃OH), which is activated with light to form hydroxyl radicals (OH⁺), which bind NO and SO2 into solid products further withdrawn. The use of a laser beam provides a positive effect, but in industrial use this process is very expensive and complicated in technical terms. Moreover, its positive effect is not very high due to the presence of water in the reactor, which limits the penetration of ultraviolet rays. One more disadvantage of the process is that due the presence of CH₃OH, it is difficult to obtain a uniform distribution of a light beam in the reactor space. Besides, it should be kept in mind that methanol (methyl alcohol CH₃OH) is a poisonous substance, and therefore one must be very careful with it.

[005] There is also known a process of removing SO₂ and NO_x from the flow of combustion products of flue gases, including their irradiation with an electron beam in the reaction zone (UA 41259), wherein the flue gas flow is additionally exposed to microwaves in the form of a continuous or pulsed flow, where the process provides that the reaction zone should be moistened and have ammonia (NH₃) introduced. A significant disadvantage of this process of removing harmful substances from the combustion products of flue gases is the complexity of the process due to the need for its irradiation with an electron beam, as well as limited scope of application due to the possibility of its use only in the power plant furnaces, and the need for safety gear, since it requires using ammonia, which increases the technology cost.

Disclosure of the Invention

[006] The objective of the claimed invention is overcoming of the drawbacks of the prior art and providing a process and an efficient compact device for separation of a selected gaseous component from a gas mixture, for instance exhaust gas or polluted air.

[007] In the process of separation of a selected gaseous component, comprising supplying an electromagnetic radiation at frequency substantially within the range of natural frequency of molecules of the gaseous component selected to be separated from the gas mixture; passing a gas mixture through the created electromagnetic field; and further passing the gas mixture towards a membrane, having pore size adapted to allow selected gaseous component to pass through the membrane pores.

[008] According to the preferred embodiment, the process further comprising the step of discharging detained by the membrane gas mixture components.

[009] The claimed device for separation of a selected gaseous component from a gas mixture comprises: an inlet adapted to be connected to the supply of a gas mixture; an outlet; a microwave generator adapted for supplying an electromagnetic radiation; a membrane module comprising a membrane or a set of membranes, having pore size adapted to allow selected gaseous component to pass through the membrane; the membrane module being mounted so to allow passing of the gas mixture subjected to electromagnetic radiation by the microwave generator towards the membrane and to allow the selected gaseous component molecules to pass through the membrane pores towards the device’s outlet.

[010] According to the preferred embodiment the microwave generator is adapted to allow selection of frequency of electromagnetic radiation substantially within the range of natural frequency of molecules of the gaseous component to be separated from the gas mixture.

[Oil] According to yet preferred embodiment the device is further provided with means for discharging detained by the membrane gas mixture components.

Brief Description Of Drawings

[012] Fig. 1 is a schematic representation of the claimed device according to one embodiment;

Fig. 2 is a schematic representation of the process of O2 separation from the N2, having different frequency of oscillations.

Fig. 3 is a schematic representation of the process of CO2 separation from the exhaust gas mixture.

[013] The device for a selected gaseous component separation from gas mixture, e.g. air or exhaust gases is provided with an inlet adapted to be connected to the supply of a gas mixture and an outlet for the separated gas output (Fig. 1). A microwave generator and a membrane are mounted inside the device. The selected gas component’s separation process starts with switching on a power supply for the microwave generator, which forms a microwave oscillatory process, with the amplitude and frequency of vibrations chosen to resonate with the vibrations of the separated gaseous component (e.g. nitrogen containing or carbon dioxide containing component molecules of the gas mixture). The selected frequency of the microwaves created by the microwave generator prevents passing the molecules of separable component one of the gas mixture in the membrane pores. Because of the selected frequency of electromagnetic radiation, created by the microwave generator it does not considerably affect molecules of the separable component two of the gas mixture. Thus, the latter pass through the membrane (Fig. 2- Fig. 3).

[014] Thus, the process and the device claimed can be implemented employing such gas molecules characteristics, as frequency of oscillations, weight and size. For instance, while size of oxygen and nitrogen molecules is quite similar, their weight is sufficiently different. Thus, oxygen and nitrogen molecules have substantially different frequency of oscillations. As nitrogen molecules’ frequency of oscillations is in the ultraviolet range of wavelength, for oxygen separation from the nitrogen-containing component the working regime of the microwave generator should be selected substantially within the same range of wavelengths. Namely, the selected frequency of radiation should be in the range from 8 x 10¹³ Hz to 6 x 10¹³ Hz. This increases the nitrogen molecules’ frequency of oscillations, while oxygen molecules’ frequency of oscillations remains in its natural range, which allows oxygen molecules to pass through the pores of the membrane. The material of the membrane in case of oxygen separation from the nitrogen-containing component should be selected so that the size of pores of the membrane is within the range 0.4-0.9 nm.

[015] According to the preferred embodiment, the membrane is made of a polymer material. The polymer material is selected according to the required permeability and selectivity, which is defined by the components to be separated. According to another embodiment, an anticorrosive material (for example, glass fiber) is used as a reinforcement for the polymer membrane. According to yet another embodiment the device comprises a membrane module, comprising a set of removable membranes. Examples of Implementation of the Invention

[016] Example 1

Obtaining oxygen by separation of nitrogen from the polluted air. The electromagnetic radiation at a frequency in the range from 8 x 10¹³ Hz to 6 x 10¹³ Hz is supplied. A gas mixture is passed into the device’s inlet and further - through the electromagnetic field created by the microwave generator. Further the gas mixture is passed towards a membrane, having pore size in the range of 0.4 - 0.9 nm. Size of oxygen and nitrogen molecules is quite similar: 0.3 nm and 0.32 nm respectively, where weight of the molecules is sufficiently different, namely, O2 = 32 g/mol and N2 = 28.02 g/mol. Subjecting the gas mixture to electromagnetic radiation with the selected frequency increases the nitrogen molecules’ frequency of oscillations, while oxygen molecules’ frequency of oscillations remains in its natural range, which allows oxygen molecules to pass through the pores of the membrane (Fig. 1 - Fig. 2) .

[017] According to production and experimental tests, the purification of gaseous combustion products from NO_x makes up to 98%. The temperature of the separation process is maintained within 90-100 °C, with the resonator power not exceeding 100 Watts. Depending on the field of use, separator's electrical parameters can be changed. So, to decontaminate heat and power plants from waste gases, the voltage for the operation of the microwave generator should preferably be 220V, and when used for purifying the exhaust gases of the internal combustion engine, the voltage should be 12V, with the appropriate circuitry and switching equipment

[018] Example 2

Obtaining carbon dioxide by its separation from the exhaust gas mixture. The electromagnetic radiation at a frequency in the range of 7. 5 ^c 10¹³ Hz to 1. 5 ^c 10¹³ Hz is supplied. A gas mixture is passed into the device’s inlet and further - through the electromagnetic field created by the microwave generator. Further the gas mixture is passed towards a membrane, having pore size in the range of 0.4 - 0.9 nm. Due to different range of natural frequencies of molecules in the exhaust gas mixture, subjecting the gas mixture to electromagnetic radiation with the selected frequency increases the carbon dioxide molecules’ frequency of oscillations, while other gaseous component molecules’ frequency of oscillations remains in its natural range, which allows them to pass through the pores of the membrane, while carbon dioxide molecules are detained by the membrane (Fig. 3), which allows separation and further discharge of the carbon dioxide from the device.

Claims

1. A process for separation of a selected gaseous component from a gas mixture, comprising the following steps: i) supplying an electromagnetic radiation at frequency substantially within the range of natural frequency of molecules of the gaseous component selected to be separated from the gas mixture; ii) passing a gas mixture through the created electromagnetic field; iii) further passing the gas mixture towards a membrane, having pore size adapted to allow selected gaseous component to pass through the membrane pores.

2. The process according to claim 1, wherein the selected gaseous component to be separated from the gas mixture is oxygen, where the frequency of electromagnetic radiation is selected from the range of 8 x 10¹³ Hz to 6 x 10¹³ Hz and the membrane pore size is in the range of 0.4 - 0.9 nm, so to allow oxygen molecules to pass through the membrane.

3. The process according to claim 1, wherein the selected gaseous component to be separated from the gas mixture is carbon dioxide, where the frequency of electromagnetic radiation is selected from the range of 7.5 x 10¹³ Hz to 1.5 x 10¹³ Hz and the membrane pore size is in the range of 0.4 - 0.9 nm, so to allow carbon dioxide molecules to be detained by the membrane.

4. The process according to any proceeding claims, further comprising the step iiia) of discharging detained by the membrane gas mixture components.

5. A device for separation of a selected gaseous component from a gas mixture, comprising an inlet adapted to be connected to the supply of a gas mixture; an outlet; a microwave generator adapted for supplying an electromagnetic radiation; a membrane module comprising a membrane or a set of membranes, having pore size adapted to allow selected gaseous component to pass through the membrane; the membrane module being mounted so to allow passing of the gas mixture subjected to electromagnetic radiation by the microwave generator towards the membrane and to allow the selected gaseous component molecules to pass through the membrane pores towards the device’s outlet.

6. The device according to claim 5, wherein the microwave generator is further adapted to allow selection of frequency of electromagnetic radiation substantially within the range of natural frequency of molecules of the gaseous component to be separated from the gas mixture.

7. The device according to any claims from 5 to 6, wherein the device is adapted for separation of oxygen from the gas mixture, where the microwave generator is adapted to allow selection of frequency of electromagnetic radiation in the range of 8 x 10¹³ Hz to 6 x 10¹³ Hz and the membrane pore size is in the range of 0.4 - 0.9 nm.

8. The device according to any claims from 5 to 6, wherein the device is adapted for separation of carbon dioxide from the gas mixture, where the microwave generator is adapted to allow selection of frequency of electromagnetic radiation in the range of 7.5 x 10¹³ Hz to 1.5 x 10¹³ Hz and the membrane pore size is in the range of 0.4 - 0.9 nm.

9. The device according to any claims from 5 to 8, wherein the device is further provided with means for discharging detained by the membrane gas mixture components.

10. The device according to any claims from 5 to 9, wherein the membrane or a set of membranes are made from a polymer, preferably, from a polymer reinforced by an anticorrosive material.