MOBILE INDUSTRIAL GAS TREATMENT DEVICES AND CHASSIS

Abstract

TITLE: MOBILE DEVICES AND CHASSIS FOR INDUSTRIAL GAS TREATMENT The industrial gas drying device (22) comprises at least one heater (36) connected to the inlet of industrial gas to be dried in the device, a first drying column (30) operating by adsorption with external or internal regeneration, a second drying column (31) operating by adsorption with external or internal regeneration, a cooler (37), a separator (38) associated with a purge pot (40) and a set of multi-way valves (32 to 35).These multi-way valves are controlled so that, while one of the drying columns dries industrial gas coming from the industrial gas inlet to be dried, the other of the drying columns is regenerated by industrial gas to be dried, the industrial gas having passed through this other drying column passing successively through the cooler, the separator associated with the purge pot and the industrial gas inlet to be dried of the drying column drying industrial gas. Figure for abstract: Figure 5.

Description

Title of the invention: MOBILE DEVICES AND CHASSIS FOR INDUSTRIAL GAS TREATMENT Technical field of the invention

[0001] The present invention relates to an industrial gas drying device, an industrial gas purification device and skids (otherwise called "mobile chassis") comprising these devices. It applies, in particular, to the purification of hydrogen H2, compressed air, nitrogen N2, carbon dioxide CO2, oxygen O2 or methane CH4, during their production. State of the art

[0002] The main resources for producing dihydrogen H2 are water and hydrocarbons (coal, oil or natural gas). The gas produced requires treatment because it contains impurities depending on the process such as dioxygen O 2 and water H2O, which means that its purity does not meet the requirements of certain uses. Statement of the invention

[0003] The present invention aims to remedy all or part of these drawbacks.

[0004] To this end, according to a first aspect, the present invention relates to a device for drying industrial gas, which comprises at least one heater connected to the inlet of industrial gas to be dried in the device, a first drying column operating by adsorption with external or internal regeneration, a second drying column operating by adsorption with external or internal regeneration, a cooler, a separator associated with a purge pot and a set of multi-way valves controlled so that, while one of the drying columns dries industrial gas coming from the inlet of industrial gas to be dried, the other of the drying columns is passed through by industrial gas to be dried heated by a said heater, the industrial gas having passed through this other drying column passing successively through the cooler, the separator associated with the purge pot and the inlet of industrial gas to be dried of the drying column drying industrial gas.

[0005] Thanks to these arrangements, a portion of the industrial gas flow is directly dried in one of the drying columns while another portion of the flow is used for the regeneration of the other drying column. The regeneration of one of the drying columns while the other is operating in drying mode is thus carried out efficiently and without loss of industrial gas. In addition, the flow of dried industrial gas is uninterrupted.

[0006] In embodiments, the multi-way valves are controlled so that while one of the drying columns is drying industrial gas from the inlet of industrial gas to be dried, the other of the drying columns is successively passed through by industrial gas to be dried heated by a said heater then by industrial gas to be dried coming from the inlet of industrial gas to be dried without passing through a heater, the industrial gas having passed through this other drying column passing, successively, through the cooler, the separator associated with the purge pot and the inlet of industrial gas to be dried of the drying column drying industrial gas.

[0007] Thanks to these arrangements, a part of the industrial gas flow is directly dried in one of the drying columns while another part of the flow is used first to heat the other drying column and then to cool it, this other part of the flow then being cooled, freed in the separator from the condensed water by the cooling and then injected into the drying column during the drying of industrial gas. The regeneration of one of the drying columns while the other is operating is thus done efficiently and without loss of industrial gas.

[0008] In embodiments, the multi-way valve assembly comprises a first four-way valve for inlet of industrial gas to be dried and a second four-way valve for outlet of dried industrial gas, each drying column comprising an inlet pipe for the industrial gas to be dried connected to the first four-way valve and an outlet pipe for the dried industrial gas connected to the second four-way valve,

[0009] the first four-way valve conveying, between two of its ways, industrial gas to be dried alternately to the first or second drying column and, between its other two ways, alternately, industrial gas to be dried coming successively from a said heater and, respectively, from the second or first drying column, then industrial gas coming from the industrial gas inlet of the drying device without passing through a heater to the inlet pipe of the second or first drying column, respectively,

[0010] the second four-way valve conveying, between two of its ways, dried industrial gas from the first or second drying column, respectively, and, between its other two ways, reheated industrial gas coming from a said heater to the outlet pipe of, respectively, the second or first drying column then industrial gas coming from, respectively, the second or first drying column to, successively, the cooler, the separator and the inlet of industrial gas to be dried of the first four-way valve.

[0011] The simultaneous switching of the four-way valves ensures the continuity of drying of the industrial gas flow, without jolts.

[0012] In embodiments, the multi-way valve assembly further comprises a first three-way valve, one of which is always open and is connected to the first four-way valve and the other open way of which is alternately a way connected to the entry of the industrial gas into the drying device without passing through a said heater and a path connected to the cooler, and a second three-way valve of which one path always open is connected to the second four-way valve and of which the other open path is, respectively, alternately a path connected to the cooler and a path connected to a said heater.

[0013] The simultaneous switching of the three-way valves ensures the transition between the heating phase of the column being regenerated and the cooling phase of this column being regenerated.

[0014] In embodiments, each drying column comprises a charge of molecular sieve type adsorbent.

[0015] Drying is thus particularly effective.

[0016] In embodiments, the drying device comprises, at the outlet, a micron dust removal filter.

[0017] It is recalled here that a micron filter is of the grade of one micron.

[0018] According to a second aspect, the present invention relates to an industrial gas purification device, which comprises a deoxygenation unit and, downstream of the deoxygenation unit, a drying device which is the subject of the first aspect of the invention.

[0019] In embodiments, the deoxygenation unit comprises, at the outlet of the industrial gas to the drying device, a cooler and a separator associated with a purge pot and receiving industrial gas leaving this cooler.

[0020] Thus, even before entering the drying device, the industrial gas is already partially freed from the condensable water it contains.

[0021] In embodiments, the deoxygenation unit successively comprises, on the industrial gas path: - a mist eliminator or separator filter, - a heater, - a deoxidizing catalytic column and - a cooler.

[0022] The industrial gas purification device which is the subject of the invention thus achieves the deoxygenation of the industrial gas upstream of its drying.

[0023] In embodiments, each cooler is a tubular exchanger cooled with glycolated water.

[0024] The tubular exchangers cooled with glycolated water have, compared to other types of exchangers, in combination with the other technical characteristics of the invention, the following advantages: - they have a longer lifespan, - they are more reliable, - they are easier to position in a skid, and - they have better resistance to pressure and temperature.

[0025] In embodiments, the deoxygenation unit and the drying device are configured to process industrial gas flow rates of between 5 NmVh and 25,000 NmVh with pressures of 15 barg to 40 barg. It is recalled that “Nm3” means “normal cubic meters”, a flow rate unit which makes it possible to compare measurements carried out under different and real conditions, brought back to the absolute normative conditions of 0°C and 1 bar.

[0026] According to a third aspect, the present invention relates to a skid which comprises a drying device which is the subject of the first aspect of the present invention.

[0027] In embodiments, this skid which comprises a purification device which is the subject of the second aspect of the present invention.

[0028] It is recalled that a skid designates a mobile chassis type structure on which a set of equipment, pipes and / or industrial materials is fixed. This makes it possible to transport a set of "ready-to-use" and already assembled functions rather than transporting them one by one and having to assemble them on site.

[0029] The advantages of the drying device and the skids which are the subject of the second and third aspects of the invention being similar to those of the purification device which is the subject of the invention, they are not recalled here. Brief description of the figures

[0030] Other advantages, aims and particular characteristics of the invention will emerge from the following non-limiting description of at least one particular embodiment of the devices and skids which are the subject of the present invention, with reference to the appended drawings, in which:

[0031] [Fig-1] schematically represents a deoxygenation part of a first mode of production of a purification unit which is the subject of the invention,

[0032] [Fig.2] schematically represents a first embodiment of a drying device which is the subject of the invention,

[0033] [Fig.3] schematically represents a first operating configuration of a drying device of the unit represented in [Fig.2], in which a first column is in a drying phase and a second column is in a heating phase,

[0034] [Fig.4] schematically represents a second operating configuration of the drying device of the unit represented in [Fig.2], in which the first column is in a drying phase and the second column is in a cooling phase,

[0035] [Fig.5] schematically represents a third operating configuration of the drying device of the unit represented in [Fig.2], in which the first column is in a cooling phase and the second column is in a drying phase,

[0036] [Fig.6] schematically represents a fourth operating configuration of the drying device of the unit represented in [Fig.2], in which the first column is in a heating phase and the second column is in a drying phase,

[0037] [Fig.7] schematically represents a second embodiment of a drying device which is the subject of the invention, in a first operating configuration in which a first column is in a drying phase and a second column is in a regeneration phase, and

[0038] [Fig.8] schematically represents the drying device illustrated in [Fig.7], in a second operating configuration in which the first column is in a regeneration phase and the second column is in a drying phase. Detailed description

[0039] The present description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment in an advantageous manner.

[0040] It should be noted, from now on, that the figures are not to scale.

[0041] Throughout the description, a drying device which is the subject of the invention is called a “dryer”.

[0042] The invention being particularly applicable to the drying and purification of hydrogen, throughout the description, a device for drying and purifying hydrogen is described. However, the present invention is not limited to this industrial gas but extends, on the contrary, to all industrial gases, for example, compressed air, nitrogen N2, carbon dioxide CO2, oxygen O2 or methane CH4. Of course, in the case of oxygen, the purification device does not include a deoxygenation unit.

[0043] The invention relates in particular to a device 20 for purifying hydrogen gas (H2) to eliminate the water and oxygen that the hydrogen contains during its production. In a preferred embodiment illustrated in FIGS. 1 to 6, this device 20 takes the form of a skid composed of a deoxygenation unit (“deoxo”) 21 upstream of a dryer 22 operating by adsorption with external or internal regeneration with wet gas heat (without loss of gas). This dryer 22 is preferably of the SRE-GH type (with external regeneration) or of the SRLGH type (with internal regeneration).

[0044] Preferably, a mist eliminator or separator filter 23 is provided at the inlet of the device and a micron dust removal filter 24 is provided at the outlet. Alternatively, the skid only includes the drying device, or dryer.

[0045] This device 20 processes flow rates of 25 Nm3 / h to 25,000 Nm3 / h with pressures of 15 barg to 40 barg, to achieve a hydrogen purity of 99.999991%.

[0046] In more detail, the deoxygenation part 21 of the device 20 illustrated in figures 1 to 6 comprises: a. The deoxygenation unit (“deoxo”) 21 This deoxygenation unit 21 comprises an electric heater 25 upstream of a catalytic column 27 and a cooler 26 downstream. The composition of the catalytic column 27 comprises, in particular: - 316 L stainless steel boilerwork with a stainless steel strainer to retain the catalyst, - an upper opening and a lower opening to load and unload the catalyst, - a 28 pipe for the arrival of the oxygen and hydrogen mixture, - a 29 outlet pipe for the treated gas, and - a catalyst charge of the Pt (platinum) or Pd (palladium) type on alumina, b. The electric heater 25, c. The cooler 26, for example a tubular exchanger cooled with glycolated water. Dryer 22 is, for example, of the SRE-GH type (external regeneration). The dryer 22 comprises two columns, 30 and 31, each comprising: - a stainless steel boiler body with stainless steel strainers to retain the adsorbent, - an adsorbent loading port in the upper part and an unloading port in the lower part, - inlet and outlet pipes for the gas to be treated which are connected to automatic gas distribution valves 32 to 35, and - a molecular sieve type adsorbent charge.

[0047] The dryer 22 also comprises: - an electric heater 36 for explosive atmospheres (“ATEX”), which heats the gas during the regeneration phase, - the distribution assembly of two 4-way valves 32 and 33, mechanically connected, - the distribution assembly of two 3-way valves 34 and 35 mechanically secured, - a tubular exchanger 37 cooled with glycolated water, - a separator 38 with purge pots 40, at the outlet. - a separator 39, with purge pots 41, at the inlet. A cold group 42 supplying glycolated water in a closed circuit to the cooler 26 and to the tubular exchanger 37, is installed in a non-ATEX healthy zone (explosive atmosphere).

[0048] The purification device 20 also comprises: - control instruments 43: pressure indicators and transmitters, temperature indicators and transmitters, limit switches, flow meters, - a 44 hydrogen, oxygen and hygrometry analyzer, and - a control system 45: The control and piloting of the installation is carried out using an electrical cabinet (equipped with a programmable controller and a man / machine interface).

[0049] Alternatively, the dryer 22 is of the SRLGH type (with internal regeneration) as illustrated in figures 7 and 8. This type of SRLGH dryer is preferential in the case where the necessary heating power is limited, to avoid heat losses.

[0050] At the inlet and outlet of the purification device 20, three-way valves 46 are provided to inert the device 20 with a neutral gas (for example nitrogen N2) and push the flow of hydrogen H2 towards a flare in the event of a hydrogen production shutdown.

[0051] At the inlet, the hydrogen gas passes through the separator 23 to remove the water vapor. Then this gas is heated to 100°C before entering the deoxidizing catalytic column 27 to initiate and maintain the reaction in the catalyst and obtain the best performance. The reaction in the catalytic column 27 eliminates the oxygen and causes adiabatic heating of 160 times the oxygen concentration. As a result, at the outlet of the catalytic column 27, the oxygen is eliminated and the hot hydrogen is saturated with water.

[0052] Upstream of the dryer 22, the tubular exchanger 26 cooled with glycolated water cools the gas before it enters the dryer 22, so that it reaches a temperature between 11°C and 16°C.

[0053] At the outlet of this tubular exchanger 26, the wet gas arrives in the separator 38 equipped with a purge pot 40 via a valve 47. The purge pot 40 is equipped with three level detectors 43 (very high level, high level and a low level) to avoid having a gas leak during the evacuation of the condensates. Indeed, the valve 47 at the outlet of the separator 38 is open until the high level is reached in the purge pot 40. When this is the case, the valve 47 closes and a valve 48 at the outlet of the purge pot 40 opens to evacuate the condensates. When the low level is reached in the purge pot 40, the valve 48 at the outlet of the purge pot closes and the valve 47 at the outlet of the separator 38 opens.

[0054] After being cooled by the exchanger 26, the wet gas is channeled towards the dryer 22 to eliminate the water it contains.

[0055] The dryer 22 operates cyclically in three phases, a drying phase and two regeneration phases, the two columns operating simultaneously, one being in the drying phase and the other in one of the regeneration phases. Half-cycle durations are defined according to service conditions.

[0056] The regeneration is divided into two phases: a heating phase and a cooling phase. During the heating phase, a portion of the flow (between 5% and 30%) of the wet gas, a portion called the “regeneration flow”, is taken from the inlet of the dryer 22 and heated by the electric heater 36 (to reach a temperature between 180°C and 200°C). This cooling flow passes through the column 30 or 31 being regenerated, from the bottom to the top, to regenerate the adsorbent product it contains. Then, the regeneration flow is cooled by the cooler 37 to the inlet temperature in the dryer 22, i.e. between 11 and 16°C, and filtered (to extract the water vapor) by the separator 38.

[0057] To avoid gas loss, the regeneration flow is reinjected into the drying flow of the column in the drying phase, 31 or 30 respectively.

[0058] This regeneration flow is regulated through a control valve 49 which is controlled using a flow meter 50.

[0059] During the cooling phase: a part of the flow (between 5% and 30%) entering the dryer 22 (wet gas), part called “cooling flow”, is taken at the inlet of the dryer 22 through a valve 51, for example manually adjusted. The manual adjustment valve makes it possible to obtain approximately the same pressure drop in the cooling circuit as that of the heating circuit, there are in fact more pressure drops on the hot circuit than on the cold circuit.

[0060] This cooling flow passes through the column, 30 or 31 respectively, from top to bottom to cool the hot adsorbent product it contains.

[0061] As during the heating phase, this cooling flow is reinjected into the column, 31 or 30 respectively, which is being dried.

[0062] When column 30 or 31 is regenerated, it switches to the drying phase and the other column switches to the regeneration phase. The switching is done automatically using the 3-way valves 34 and 35 (switching between the two regeneration phases) and 4-way valves 32 and 33 (switching between the drying phase and the regeneration phase of the two columns).

[0063] Thanks to the implementation of these phases, drying and regeneration are carried out without loss of gas.

[0064] [Fig. 3] illustrates the configuration of the dryer 22 when the column 30 is in the drying phase and the column 31 is in the heating phase. The solid arrows represent the path followed by the drying flow passing directly through the column 30 in the drying phase. The broken arrows represent the path followed by the regeneration flow from the column 31 before it is mixed with the drying flow. The oblique bars across the three- and four-way valves 32 to 35 represent the separation of the inlets and outlets of these valves (the flows do not pass through these bars).

[0065] [Fig. 4] illustrates the configuration of the dryer 22 when the column 30 is in the drying phase and the column 31 is in the cooling phase. The solid arrows represent the path followed by the drying flow passing directly through the column 30 in the drying phase. This path is identical to that of [Fig. 3]. The broken arrows represent the path followed by the cooling flow from the column 31 before it is mixed with the drying flow. The oblique bars across the three- and four-way valves 32 to 35 represent the separation of the inlets and outlets of these valves (the flows do not pass through these bars).

[0066] [Fig. 5] illustrates the configuration of the dryer 22 when the column 31 is in the drying phase and the column 30 is in the heating phase. The solid arrows represent the path followed by the drying flow passing directly through the column 31 in the drying phase. The broken arrows represent the path followed by the regeneration flow from the column 30 before it is mixed with the drying flow. The oblique bars across the three- and four-way valves 32 to 35 represent the separation of the inlets and outlets of these valves (the flows do not pass through these bars).

[0067] [Fig. 6] illustrates the configuration of the dryer 22 when the column 31 is in the drying phase and the column 30 is in the cooling phase. The solid arrows represent the path followed by the drying flow passing directly through the column 31 in the drying phase. This path is identical to that of [Fig. 5]. The broken arrows represent the path followed by the cooling flow from the column 30 before it is mixed with the drying flow. The oblique bars across the three- and four-way valves 32 to 35 represent the separation of the inlets and outlets of these valves (the flows do not pass through these bars).

[0068] As understood from Figures 3 to 6, the switching between the phases is done by the simultaneous change of configuration of the 4-way valves 32 and 33 initially to switch the flow of gas to be dried from one column to the other. During this drying phase in one of the columns, the 3-way valves 34 and 35 simultaneously change configuration to switch the other column from the heating phase to the cooling phase.

[0069] In the second embodiment of the drying device 70 illustrated in figures 7 and 8, this device 70 is of the SRLGH type (with internal regeneration). This dryer 60 includes the same sensors and automation as the SRE-GH type dryer 22 described with reference to figures 2 to 6, but only these main elements are illustrated in figures 7 and 8. This dryer 70 includes two heaters (not shown), each for one of the columns 60 and 61 instead of a heater 36 common to the two columns 30 and 31. In comparison with the first embodiment, in the second embodiment, the three-way valves are not necessary, nor is the cooling circuit comprising the valve 51. The heating flow is identical to the cooling one.

[0070] In the configuration illustrated in [Fig.7], the first column 60 is in the drying phase and the second column 61 is in the regeneration phase. The wet hydrogen flow (represented by solid arrows) to be dried follows the inlet pipes until it reaches a four-way valve 63 which directs it towards the first column 60. The hydrogen is dried there and then passes through the four-way valve 62 where it is directed towards a dust filter 64. The regeneration flow, extracted from the humic hydrogen flow (represented by broken arrows) first passes through the four-way valve 62 which directs it towards the second drying column 61, from where it emerges towards the four-way valve 63. At the outlet of this four-way valve 63, the regeneration gas, hot and wet, passes through a cooler 67, then a separator 68 associated with a purge pot 69.At the outlet of the separator 68, the cooled regeneration gas is returned, with the hydrogen to be dried, to the four-way valve 63, then to the first column 60.

[0071] In Figures 8, the two four-way valves 62 and 63 having switched simultaneously, the operating phases of the columns 60 and 61 are reversed, the first column 60 being in the regeneration phase and the second column 61 in the drying phase.

[0072] As understood from Figures 7 and 8, switching between the phases is done by the simultaneous change of configuration of the 4-way valves 62 and 63 to switch the flow of gas to be dried from one column to the other. Of course, the drying device illustrated in Figures 7 and 8 can be preceded by a deoxygenation unit as illustrated in [Fig.l].

[0073] Of course, the present invention is not limited to the drying and purification of hydrogen but extends to the drying and purification of all gases containing water. Concerning the catalyst, if the gas to be treated is oxygen with traces of hydrogen, the same catalyst can be used to dehydrogenate the oxygen. It can also be used to treat, for example, nitrogen to remove the traces of oxygen, however an external supply of hydrogen will be required, and vice versa if the traces of hydrogen are to be removed. Other types of catalysts or adsorbents are used to treat other gases, in a manner known to those skilled in the art.

Claims

Claims

1. Device (22, 70) for drying industrial gas, characterized in that it comprises at least one heater (36, 60, 61) connected to the inlet of industrial gas to be dried in the device, a first drying column (30, 60) operating by adsorption with external or internal regeneration, a second drying column (31, 61) operating by adsorption with external or internal regeneration, a cooler (37, 67), a separator (38, 68) associated with a purge pot (40, 69) and a set of multi-way valves (32 to 35, 62, 63) controlled so that, while one of the drying columns dries industrial gas coming from the inlet of industrial gas to be dried, the other of the drying columns is passed through by industrial gas to be dried heated by a said heater, the industrial gas having passed through this other drying column passing successively through the cooler,the separator associated with the purge pot and the inlet of industrial gas to be dried from the drying column drying industrial gas.,

2. Device (22) according to claim 1, in which the multi-way valves (32 to 35) are controlled so that, while one of the drying columns dries industrial gas coming from the inlet of industrial gas to be dried, the other of the drying columns is successively passed through by industrial gas to be dried heated by a said heater then by industrial gas to be dried coming from the inlet of industrial gas to be dried without passing through a heater, the industrial gas having passed through this other drying column passing, successively, through the cooler, the separator associated with the purge pot and the inlet of industrial gas to be dried of the drying column drying industrial gas.

3. Device (22) according to claim 2, in which the set of multi-way valves (32 to 35) comprises a first four-way valve (33) for inlet of industrial gas to be dried and a second four-way valve (32) for outlet of dried industrial gas, each drying column comprising an inlet pipe for the industrial gas to be dried connected to the first four-way valve and an outlet pipe for the dried industrial gas connected to the second four-way valve, the first four-way valve conveying, between two of its pipes, industrial gas to be dried alternately to the first or the second drying column and, between its other two pipes, alternately, industrial gas to be dried coming successively from a said heater and, respectively, from the second or first drying column, then industrial gas coming from the industrial gas inlet of the drying device without passing through a heater to the inlet pipe of the second or first drying column, respectively, the second four-way valve conveying, between two of its pipes, dried industrial gas from the first or second drying column, respectively, and, between its other two pipes, reheated industrial gas coming from a said heater to the outlet pipe of, respectively, the second or first drying column then industrial gas coming from, respectively, the second or first drying column to, successively, the cooler (37), the separator (38) and the industrial gas inlet to be dried of the first four-way valve.

4. Device (22) according to claim 3, in which the set of multi-way valves (32 to 35) further comprises a first three-way valve (35), one always open way of which is connected to the first four-way valve (33) and the other open way of which is alternately a way connected to the inlet of the industrial gas into the drying device without passing through a said heater (36) and a way connected to the cooler (37), and a second three-way valve (34) one always open way of which is connected to the second four-way valve (32) and the other open way of which is, respectively, alternately a way connected to the cooler (37) and a way connected to a said heater.

5. Device (22) according to one of claims 1 to 4, in which each drying column (30, 31) comprises a charge of molecular sieve type adsorbent.

6. Device (22) according to one of claims 1 to 5, which comprises, at the outlet, a micron dust filter.

7. Device (20) for purifying industrial gas, which comprises a deoxygenation unit (21) and, downstream of the deoxygenation unit, a drying device (22, 70) according to one of claims 1 to 6.

8. Device (20) according to claim 7, in which the deoxygenation unit (21) comprises, at the outlet of the industrial gas to the drying device (22), a cooler (26) and a separator (39) associated with a purge pot (41) and receiving industrial gas leaving this cooler (26).

9. Device (20) according to one of claims 7 or 8, in which the unit deoxygenation (21) successively comprises, on the industrial gas path: - a mist eliminator or separator filter (23), - a heater (25), - a deoxidizing catalytic column (27) and - a cooler (26).

10. Device (20) according to one of claims 7 to 9, in which each cooler (26) is a tubular exchanger cooled with glycolated water.

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