INSTALLATION AND METHOD FOR RECOVERING GASEOUS SUBSTANCES FROM GAS FLOWS

Abstract

An installation and method for recovering gaseous substances from gas flows comprising a first gas-treatment module (module 1) to receive a first inlet gas flow (1) in which the temperature and pressure are controlled in order to dry said flow by removing water, nitrogen and sulfur oxides, unburned substances and other solids in suspension, a second CO.sub.2 separation module (module 2) in which the first outlet flow (13) from module 1 is treated using a PSA adsorption/desorption process to separate the gases selected, thereby enriching the third outlet flow (27), and a third, optional module (module 3) in which the CO.sub.2 purification process is carried out and in which the third outlet flow (27) from module 2 is treated using a PSA adsorption/desorption process to separate the gases selected, thereby enriching the fifth outlet flow (44) from module 3.

Claims

1-25. (canceled)

26. An installation for recovering gaseous substances from gas flows comprising: a first atmospheric gas-treatment module equipped with: an inlet conduit of the gas flows which includes at least one substance to be recovered; a set of heat exchangers; a compression system; drying means; a series of precise active systems for the correct operation of the installation; a first gas outlet conduit for mobilizing a first outlet flow towards an atmospheric gas-separation module after a modification thereof in composition, pressure and temperature; a second outlet conduit for mobilizing a liquid flow; and a second inlet conduit for managing adsorbed gases in adsorption/desorption reactors existing in the atmospheric gas-separation module; at least one said second atmospheric gas-separation module equipped with: a first gas inlet which includes at least one substance to be recovered, coming from a first outlet flow from the atmospheric gas-treatment module; which is connected to a first inlet conduit for transporting gases to the adsorption/desorption reactors; a series of pipes and valves necessary for an operation of a PSA (Pressure Swing Adsorption) adsorption/desorption process; a first outlet conduit for mobilizing desorbed gas flow after the PSA desorption process for the sending thereof to the atmospheric gas-treatment module in which the desorption process will be controlled, according to what is required for the correct operation of a control system; and a second gas outlet depleted in selected gases coming from the adsorption/desorption reactors which perform the adsorption process; and the control system of the installation, adapted in an operation thereof to needs of the adsorbent material and to characteristics of the inlet gas flow.

27. The installation for recovering gaseous substances from gas flows according to claim 26, further comprising: a third atmospheric gas-purification module, equipped with: a first inlet gas inlet which includes at least one substance to be recovered, coming from the second outlet from the atmospheric gas-treatment module; which is connected to a first inlet conduit for transporting to the adsorption/desorption reactors, a series of pipes and valves necessary for the correct operation of the process of a PSA adsorption/desorption process; a first outlet conduit for mobilizing the desorbed gas flow after the PSA desorption process for the sending thereof to the atmospheric gas-treatment module in which the desorption process will be controlled, according to what is required for the correct operation of the control system; wherein the atmospheric gas-treatment module further includes: a third outlet conduit for sending the flow enriched with gases in at least one substance to be separated to an atmospheric gas-purification module, a third inlet conduit for managing the adsorbed gases in the adsorption/desorption reactors of the atmospheric gas-purification module); and a fourth outlet conduit for sending to the outside the flow depleted of gases in at least one substance to be separated.

28. The installation for recovering gaseous substances from gas flows according to claim 27, further comprising: a set of sensors which enable the monitoring of pressure, temperature and concentration conditions of the substance to be concentrated in the gas flow at the outlet towards an atmospheric gas-separation module; and a control system which enables the optimum concentration characteristics to be controlled of the selected gaseous substance, of the water content, of the pressure and temperature of the flow thereof, in order to optimize the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout the atmospheric gas-separation module and/or the atmospheric gas-purification module, acting on the different atmospheric gas-separation equipment which make up the atmospheric gas-treatment module.

29. The installation for recovering gaseous substances from gas flows according to claim 26, further comprising: a set of sensors which enable the monitoring of the pressure, temperature and concentration conditions of the substance to be concentrated in the outlet flow; a control system which enables the average and maximum concentration to be controlled in the substance to be separated obtained in the outlet flow of the atmospheric gas-separation module depending on what is required by technical specifications, the operation of which is automatic and adaptable without modification to the characteristics of the inlet flow to the system and to the outlet flow, which enables the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout the atmospheric gas-separation module, acting on the different atmospheric gas-separation equipment which make up the atmospheric gas-treatment module.

30. The installation for recovering gaseous substances from gas flows according to claim 26, further comprising: a set of sensors which enable the monitoring of the pressure, temperature and concentration conditions of the substance to be concentrated in the outlet flow; the control system which enables the average and maximum concentration to be controlled in the substance to be separated obtained in the outlet flow of the atmospheric gas-purification module (module 3) depending on what is required by technical specifications, the operation of which is automatic and adaptable without modification to the characteristics of the inlet flow to the system and to the outlet flow; and the control system which enables the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout the atmospheric gas-purification module, acting on the different atmospheric gas-treatment equipment which make up the atmospheric gas-treatment module.

31. The installation for recovering gaseous substances from gas flows according to claim 26, further comprising: an interconnection of one or more said atmospheric gas-treatment modules with one or more said atmospheric gas-separation modules, wherein the outlet flow from each said atmospheric gas-treatment modules is the inlet flow of each said atmospheric gas-separation modules.

32. The installation for recovering gaseous substances from gas flows according to claim 26, further comprising: an interconnection of one or more said atmospheric gas-treatment modules with one or more said atmospheric gas-separation modules and with one or more atmospheric gas-purification modules, wherein the outlet flow from each said atmospheric gas-treatment modules is the inlet flow of each said atmospheric gas-separation modules and the outlet flow from each said atmospheric gas-separation modules is the inlet flow of each said atmospheric gas-purification modules.

33. The installation for recovering gaseous substances from gas flows according to claim 26, further comprising: a set of sensors which enable the monitoring of the pressure, temperature and concentration conditions of the substance to be concentrated in the outlet flows; and the control system which enables the average and maximum concentration to be controlled in the substance to be separated obtained in the outlet flows from the atmospheric gas-treatment module, from the atmospheric gas-separation module and from the atmospheric gas-purification module depending on what is required by technical specifications, the operation of which is automatic and adaptable without modification to the characteristics of the inlet flow to the system and to the outlet flows, enabling the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout said atmospheric gas-treatment module, said atmospheric gas-separation module and said atmospheric gas-purification module, acting on the different atmospheric gas-treatment equipment which make up said atmospheric gas-treatment module.

34. A method for recovering gaseous substances from gas flows, separating a substance of interest wherein the method comprising: introduction of a first inlet flow into an atmospheric gas-treatment module, resulting in a first outlet flow with a concentration in a substance to be recovered greater than that of the first inlet flow; measurement of characteristics of flow rate, concentration, pressure and temperature of the substances of the flow to be recovered in the first outlet flow from an atmospheric gas-separation module; comparison of the previous measurements with pre-established criteria through a control system; modification of operating conditions of concentration, pressure and temperature of the first inlet flow to said atmospheric gas-treatment module and of the outlet of the first outlet flow; control and adjustment of adsorption and desorption times in order to attempt to comply with a pre-established operating criteria of the system as a whole, alternating adsorption/desorption reactors of said atmospheric gas-separation module in order to achieve a continuous operation which does not affect installation generating gases to be separated; actuation on equipment which make up said atmospheric gas-treatment module in order to perform PSA (Pressure Swing Adsorption) adsorption and desorption processes in the adsorption/desorption reactors of said atmospheric gas-separation module at the optimum point thereof of operation and performance; modification of the operating conditions of concentration, pressure and temperature of the first inlet flow to said atmospheric gas-separation module and of the outlet of the first outlet flow.

35. The method for recovering gaseous substances from gas flows, according to claim 34, further comprising: introduction of the first inlet flow into the atmospheric gas-treatment module, resulting in a first outlet flow with a concentration in the substance to be recovered greater than that of the first inlet flow; measurement of the characteristics of flow rate, concentration, pressure and temperature of the substances of the flow to be recovered in the first outlet flow from an atmospheric gas-purification module; comparison of the previous measurements with pre-established criteria through the control system; modification of the operating conditions of concentration, pressure and temperature of the first inlet flow to said atmospheric gas-treatment module and of the outlet of the first outlet flow; control and adjustment of the adsorption and desorption times in order to attempt to comply with the pre-established operating criteria of the system as a whole, alternating adsorption/desorption reactors of the atmospheric gas-separation module in order to achieve a continuous operation which does not affect the installation generating gases to be separated; actuation on the equipment which make up said atmospheric gas-treatment module in order to perform the PSA adsorption and desorption processes in the adsorption/desorption reactors of said atmospheric gas-separation module at the optimum point thereof of operation and performance; modification of the operating conditions of concentration, pressure and temperature of the first inlet flow to said atmospheric gas-separation module and of the outlet of the first outlet flow; control and adjustment of the adsorption and desorption times in order to attempt to comply with the pre-established operating criteria of the system as a whole, alternating adsorption/desorption reactors of said atmospheric gas-purification module in order to achieve a continuous operation which does not affect the installation generating gases to be separated; actuation on the equipment which make up said said atmospheric gas-treatment module in order to perform the PSA adsorption and desorption processes in the described adsorption/desorption reactors of said atmospheric gas-purification module at the optimum point thereof of operation and performance; and modification of the operating conditions of concentration, pressure and temperature of the first inlet flow to said atmospheric gas-purification module and of the outlet of the first outlet flow.

36. The installation for recovering gaseous substances from gas flows according to claim 26, further comprising: a set of sensors which enable the monitoring of pressure, temperature and concentration conditions of the substance to be concentrated in the gas flow at the outlet towards an atmospheric gas-separation module; and a control system which enables the optimum concentration characteristics to be controlled of the selected gaseous substance, of the water content, of the pressure and temperature of the flow thereof, in order to optimize the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout the atmospheric gas-separation module and/or the atmospheric gas-purification module, acting on the different atmospheric gas-separation equipment which make up the atmospheric gas-treatment module.

37. The installation for recovering gaseous substances from gas flows according to claim 27, further comprising: a set of sensors which enable the monitoring of the pressure, temperature and concentration conditions of the substance to be concentrated in the outlet flow; the control system which enables the average and maximum concentration to be controlled in the substance to be separated obtained in the outlet flow of the atmospheric gas-purification module (module 3) depending on what is required by technical specifications, the operation of which is automatic and adaptable without modification to the characteristics of the inlet flow to the system and to the outlet flow; and the control system which enables the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout the atmospheric gas-purification module, acting on the different atmospheric gas-treatment equipment which make up the atmospheric gas-treatment module.

38. The installation for recovering gaseous substances from gas flows according to claim 27, further comprising: an interconnection of one or more said atmospheric gas-treatment modules with one or more said atmospheric gas-separation modules, wherein the outlet flow from each said atmospheric gas-treatment modules is the inlet flow of each said atmospheric gas-separation modules.

39. The installation for recovering gaseous substances from gas flows according to claim 27, further comprising: an interconnection of one or more said atmospheric gas-treatment modules with one or more said atmospheric gas-separation modules and with one or more atmospheric gas-purification modules, wherein the outlet flow from each said atmospheric gas-treatment modules is the inlet flow of each said atmospheric gas-separation modules and the outlet flow from each said atmospheric gas-separation modules is the inlet flow of each said atmospheric gas-purification modules.

40. The installation for recovering gaseous substances from gas flows according to claim 31, further comprising: an interconnection of one or more said atmospheric gas-treatment modules with one or more said atmospheric gas-separation modules and with one or more atmospheric gas-purification modules, wherein the outlet flow from each said atmospheric gas-treatment modules is the inlet flow of each said atmospheric gas-separation modules and the outlet flow from each said atmospheric gas-separation modules is the inlet flow of each said atmospheric gas-purification modules.

41. The installation for recovering gaseous substances from gas flows according to claim 38, further comprising: an interconnection of one or more said atmospheric gas-treatment modules with one or more said atmospheric gas-separation modules and with one or more atmospheric gas-purification modules, wherein the outlet flow from each said atmospheric gas-treatment modules is the inlet flow of each said atmospheric gas-separation modules and the outlet flow from each said atmospheric gas-separation modules is the inlet flow of each said atmospheric gas-purification modules.

42. The installation for recovering gaseous substances from gas flows according to claim 28, further comprising: a set of sensors which enable the monitoring of the pressure, temperature and concentration conditions of the substance to be concentrated in the outlet flows; and the control system which enables the average and maximum concentration to be controlled in the substance to be separated obtained in the outlet flows from the atmospheric gas-treatment module, from the atmospheric gas-separation module and from the atmospheric gas-purification module depending on what is required by technical specifications, the operation of which is automatic and adaptable without modification to the characteristics of the inlet flow to the system and to the outlet flows, enabling the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout said atmospheric gas-treatment module, said atmospheric gas-separation module and said atmospheric gas-purification module, acting on the different atmospheric gas-treatment equipment which make up said atmospheric gas-treatment module.

43. The installation for recovering gaseous substances from gas flows according to claim 30, further comprising: a set of sensors which enable the monitoring of the pressure, temperature and concentration conditions of the substance to be concentrated in the outlet flows; and the control system which enables the average and maximum concentration to be controlled in the substance to be separated obtained in the outlet flows from the atmospheric gas-treatment module, from the atmospheric gas-separation module and from the atmospheric gas-purification module depending on what is required by technical specifications, the operation of which is automatic and adaptable without modification to the characteristics of the inlet flow to the system and to the outlet flows, enabling the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout said atmospheric gas-treatment module, said atmospheric gas-separation module and said atmospheric gas-purification module, acting on the different atmospheric gas-treatment equipment which make up said atmospheric gas-treatment module.

44. The installation for recovering gaseous substances from gas flows according to claim 32, further comprising: a set of sensors which enable the monitoring of the pressure, temperature and concentration conditions of the substance to be concentrated in the outlet flows; and the control system which enables the average and maximum concentration to be controlled in the substance to be separated obtained in the outlet flows from the atmospheric gas-treatment module, from the atmospheric gas-separation module and from the atmospheric gas-purification module depending on what is required by technical specifications, the operation of which is automatic and adaptable without modification to the characteristics of the inlet flow to the system and to the outlet flows, enabling the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout said atmospheric gas-treatment module, said atmospheric gas-separation module and said atmospheric gas-purification module, acting on the different atmospheric gas-treatment equipment which make up said atmospheric gas-treatment module.

45. The installation for recovering gaseous substances from gas flows according to claim 36, further comprising: a set of sensors which enable the monitoring of the pressure, temperature and concentration conditions of the substance to be concentrated in the outlet flows; and the control system which enables the average and maximum concentration to be controlled in the substance to be separated obtained in the outlet flows from the atmospheric gas-treatment module, from the atmospheric gas-separation module and from the atmospheric gas-purification module depending on what is required by technical specifications, the operation of which is automatic and adaptable without modification to the characteristics of the inlet flow to the system and to the outlet flows, enabling the operation of the system at the optimum point thereof regarding pressure, concentration, moisture and temperature throughout said atmospheric gas-treatment module, said atmospheric gas-separation module and said atmospheric gas-purification module, acting on the different atmospheric gas-treatment equipment which make up said atmospheric gas-treatment module.

Description

DESCRIPTION OF THE INVENTION

[0020] To complement the description that is being made and for the purpose of helping to better understand the features of the invention, a set of drawings is attached as an integral part of said description, a set of drawings wherein the following has been depicted, with an illustrative and non-limiting character:

[0021] FIG. 1.—General view of the device of the invention and the operation thereof.

[0022] FIG. 2.—Evolution of the key parameters of the adsorption process in the device of the invention.

[0023] FIG. 3.—Evolution of the key parameters of the adsorption process in the device of the invention.

[0024] FIG. 4.—View of the installation of the invention and the operation thereof.

[0025] The present invention describes a device and a method for recovering gaseous substances from gas flows. Said method is based on performing the PSA adsorption/desorption process of the gas flow although by means of an inert adsorbent porous material selective to the gaseous substance to be separated, performed under operating conditions and by means of a method which enables efficiencies similar to the other existing systems at very competitive costs in comparison.

[0026] The invention is applicable to a multitude of gaseous substances, although substances which are within the group of greenhouse gases are preferred, mainly carbon dioxide, although the invention is also viable for recovering other greenhouse effect substances, such as water vapor, suspended particles, nitrogen oxides and sulfur oxides.

[0027] The method of the invention is based on a cycle of two or three sequential phases first comprising a treatment of the gases to be separated (module 1), second, a separation of gases (module 2) and third, a purification of the separated gas (module 3), the latter being optional depending on the characteristics of the gas flow enriched with the substance to be separated (as seen in FIG. 1).

[0028] By applying the same system for gas treatment, gas separation and gas purification (optional) with different adsorbent porous materials, previously selected, it is and can be used to separate any inlet gas flow to the system in order to enrich the final outlet flow in the previously selected gases, being applicable to any composition since the PSA adsorption/desorption process proposed, the equipment used and the porous materials proposed are inert and do not produce intermediate substances which are potentially dangerous or harmful to the environment. Likewise, the operating pressures and temperatures are relatively low and moderate (respectively) to pose a risk to the operation.

[0029] Module 1 accommodates the gases entering this phase in pressure, temperature and composition, such that from a first inlet flow (1) it gives the result of two outlet flows, a first dry gas flow prepared to enter the second phase of gas separation (13) and a second outlet flow made up of the first removed gases, mainly suspended particles, water vapor and sulfur oxides (12).

[0030] Module 2, by means of a process of separation and concentration by physical and chemical PSA adsorption, obtains from the first outlet flow (13) coming from module 1 two outlet flows: a third outlet flow (27) with a concentration of the gaseous substances to be extracted greater than those of the first inlet flow, and a fourth outlet flow (16) with a concentration of the gaseous substances to be extracted lower than those of the first inlet flow (13).

[0031] And finally, module 3, by means of a process of separation and concentration by physical and chemical PSA adsorption similar to that of the second phase, although adapted to the composition of the gas flow to be treated, which obtains from the third outlet flow coming from the previous phase (27) two outlet flows: a fifth outlet flow (44) with a concentration of the gaseous substances to be extracted greater than those of the third outlet flow coming from the previous phase, and a sixth outlet flow (34) with a concentration of the gaseous substances to be extracted lower than those of the third outlet flow coming from the previous phase.

[0032] Depending on the specific parameters of the method and the requirements of the regulations that must be met at all times, the method can have the three previous modules, only the first two, be iterative, repeating any of the three previous modules in several steps, such that the first outlet flow (13) from module 1 constitutes the inlet flow of each module 2; and the third outlet flow (27) of each module 2 is the inlet flow to each module 3.

[0033] The second outlet flow (12) from module 1 will be managed either as liquid waste or it will be able to be neutralized with bases such as NaOH or KOH, for the chemical stabilization thereof prior to being evacuated. The fourth (16) and sixth (34) outlet flows, being gaseous, will be managed according to the content thereof as value-added atmospheric gases or they will be released directly to the outside, and they will be biologically inert.

[0034] In the event that the substance is selected from greenhouse exhaust gases, the inlet flow (1) to module 1 can come from any flow comprising greenhouse gases, preferably at least one gas flow of combustion exhaust, hereinafter referred to as exhaust flow, for example, from thermal power plants with combustion of fossil fuels, biomass combustion plants, boilers that use fossil fuels or biomass to produce primary energy, etc.

[0035] Initially, said inlet flow (1) is directed, as the first inlet flow to module 1, in order to carry out the first gas treatment phase in which the temperature and pressure are controlled in order to dry said flow by removing water, nitrogen and sulfur oxides, unburned substances and other solids in suspension, preparing the first outlet flow (13) for the injection thereof into module 2, in which the gas-separation process is carried out, with a composition which enables the operation under design conditions thereof according to the specifications of the adsorbent material. The second outlet flow (12) incorporates the separated water, the sulfur oxides, the unburned substances, partially the nitrogen oxides and other solids in suspension removed from the inlet gas flow (1).

[0036] Module 2 treats the first outlet flow (13) from module 1 by means of a PSA adsorption/desorption process to separate the gases selected, enriching the third outlet flow (27) from module 2. The separation of gases occurs according to the selectivity of the adsorption process which has a certain adsorbent porous solid. In the preferred case, the porous material used is active and selective against CO.sub.2 and CO.

[0037] The adsorption and desorption processes are performed in one or more adsorption/desorption reactors (14), in series, the adsorption process acting first, followed by that of PSA desorption, indefinitely repeating these processes in an alternating manner. In order to achieve a continuous operation of module 2, it is necessary to double the number of adsorption/desorption reactors (14), such that while half performs the adsorption process, the other half performs the PSA desorption process working in parallel.

[0038] During the adsorption process (FIG. 2), the first outlet flow (13) flows through the inner and outer surfaces of the adsorbent porous material arranged inside the adsorption/desorption reactors. The fourth outlet flow (16) is depleted in the selected gases and can be released to the outside with a composition very similar to that of the outside atmosphere, or by trying to have it recovered as industrial gases. The selected gases remain inside the adsorption/desorption reactors (14) adhered by means of Van der Waals forces, weak bonds and hydrogen bonds, among other forces of physical/chemical origin which are present. The adsorption process ends when the adsorbent porous material inside the adsorption/desorption reactors (14) becomes saturated and stops adsorbing the selected gases.

[0039] During the adsorption process, the adsorption/desorption reactors (14) which perform the adsorption process are connected to the first outlet flow (13) from module 1 and are isolated from the PSA desorption system. During the PSA desorption process, the adsorption/desorption reactors (14) are isolated from the first outlet flow (13) from module 1 and are connected to the vacuum system which will enable the extraction of the gases adhered to the adsorbent porous material contained therein in order to enrich the third outlet gas flow (27) from module 2, enriched in the selected gases.

[0040] The fourth outlet flow (16) from module 2 consists of the gas flow depleted in the selected gases coming from the adsorption/desorption reactors (14) which are performing the adsorption process, which will be able to be managed as atmospheric gases with added value, or it will be emitted directly to the outside atmosphere if it is biologically inert.

[0041] In Module 2, the desorbed gas stream follows three different steps.

[0042] (a)=Step 1=First step of the proposed PSA desorption process. Recirculation of absorbed gases

[0043] (b)=Step 2=Second step of the proposed PSA desorption process. Vacuum desorption.

[0044] (c)=Step 3=Third step of the proposed PSA desorption process. Pulled desorption.

[0045] During the first step of the PSA desorption process the flow (21) is reinjected into the inlet gas flow to module 1, while the control system (45) of the system as a whole has it. Secondly, during the second step of the PSA desorption process, the gases are accumulated in several buffer tanks for storage before leaving this phase, constituting the third outlet gas flow (27) from module 2, ending when it is possible to desorb approximately the same mass of selected gases that was initially adsorbed during the adsorption process (FIG. 3 describes the evolution of the key parameters during the PSA desorption process proposed in the present invention).

[0046] The third step is repeated several times, as many as necessary to finish the second step, interrupting it, consisting of the reinjection of the gases desorbed and accumulated in the aforementioned tanks, for the injection thereof, as a flow (24) into the adsorption/desorption reactors (14) which are performing the PSA desorption process in an explosive manner, when the pressure thereof reaches a threshold value below a predetermined vacuum (approximately 80%), in order to pull the largest number of molecules from the selected gases and improve the behavior of the vacuum pumps used to perform the PSA desorption process. At the end of each of the third steps, the second step of the desorption process continues to be performed.

[0047] In the event that the concentration of the selected gases present in the third outlet flow (27) from module 2 is less than that required by specifications of the system, a module 3, based on the previous PSA adsorption/desorption process will be included.

[0048] The operation of the module 3 will be similar and in series to the operation of the previous module 2, using as inlet gas flow the third outlet flow (27) enriched in the selected gases coming from module 2, using the same (or different) adsorbent porous material as the one used in module 2, provided that it is selective towards the gases selected for the separation and purification thereof.

[0049] The sixth outlet gas flow (34) from the third gas purification phase may be reinjected to the adsorption/desorption reactors (31) which are performing the adsorption process in both module 2 and module 3; or be emitted directly to the outside atmosphere, depending on the composition thereof and whether or not it is biologically inert, as determined through the control system (45) of the invention.

[0050] In order to achieve the continuous operation of the system as a whole, modules 2 and 3 will each have half of the adsorption/desorption reactors (14), (31) performing the adsorption process, while the other half will be performing the PSA desorption process. When both processes end, the control system (4) will alternate the operation thereof, achieving that half of the adsorption/desorption reactors (14), (31) of each module are performing the adsorption process at all times, continuously and without affecting the flow rate of the first inlet flow (1) to module 1.

[0051] In the meantime, the other half of the adsorption/desorption reactors of each phase will be performing the described PSA desorption process. At all times, the control system (45) will attempt to adjust the adsorption (t.sub.adsorption) and desorption (t.sub.desorption) times as much as possible, such that it will always meet the condition that t.sub.desorption≤t.sub.adsorption in each of modules 2 and 3.

[0052] The threshold points or values of the concentration of the selected gases in the desorbed flows (27) and (44), the concentration of the selected gases in the inlet flow to the system (1), the amount of water and other greenhouse gases present in the inlet flow to the system (1), the pressure and temperature conditions thereof, the mass and/or volumetric concentrations thereof; and the adsorption and desorption times of the adsorption/desorption reactors (14), (31) of modules 2 and 3 are, apart from multiple signals internal to the system as a whole, the main inputs which govern the control system (45) of the invention.

[0053] It is important to note that the proposed device and method can, in theory, be used at any pressure and temperature, although, depending on the features, known in the state of the art, of the PSA adsorption/desorption systems using porous materials as adsorbent material, pressures below 10 bar(g) have been selected as the operating pressure range, and operating temperatures not higher than 50° C., in order to protect the porous material used, obtaining an acceptable performance of the system as a whole and reducing the operation and maintenance costs.

[0054] In the case of the adsorption steps to be performed by the adsorption/desorption reactors (14), (31), of modules 2 and 3, the system will try to optimize the adsorption process by maximizing the amount of the selected gases such that the adsorbed amount is maximized as much as possible, exceeding 95% of the amount present in the first inlet flow to the system and as close as possible to 100%.

[0055] The basic parameters of the method are as follows:

[0056] the nature and concentration of the substance or substances to be separated present in the first inlet flow (1) to module 1.

[0057] the minimum percentage by weight which is required to be removed of each substance, with respect to the percentage of said substance contained in the first inlet flow (1) to module 1.

[0058] the minimum concentration of each separate substance required for the third outlet gas flow (27) of module 2 or the fifth outlet gas flow (44) of module 3 (optional), as required.

[0059] The system as a whole will enable the installation and operation thereof regardless of the source of greenhouse gases, pressure, temperature and concentration of the selected gaseous substance, adapting the operation thereof automatically.

[0060] The system as a whole is modular, interchangeable, compact and scalable.

[0061] Based on said basic parameters, the operating pressure and temperature parameters of each of the three modules are selected, while with the mass concentration of the gases selected to be separated during the complete process, the different steps of the PSA desorption process will then be performed in modules 2 and 3 (optional), with the aim of achieving the mass concentration of the gases to be separated selected for the desired concentration and/or separation thereof, by means of reinjection processes in different points of the systems which make up the three modules, in order to achieve adsorption of the selected gases as much as possible in order to be separated from the main inlet gas flow (1) to module 1, increasing the adsorption and desorption yields of the system as a whole, by means of a complex control system (45).

[0062] By means of the method described in the present invention, a recovery of gaseous substances from gas flows is carried out with significant energy savings (around 45%), savings in equipment cost (around 75%) and savings in operation and maintenance costs (around 75%) compared to the methods for separating gases and capturing greenhouse gases currently in operation, as well as preventing the generation of products harmful for the environment, with the savings in carbon footprint and environmental impact that this implies.

[0063] Additionally, the method of the invention favors synergy between companies since the by-products of the method can be acquired as raw material by other companies.

PREFERRED EMBODIMENT OF THE INVENTION

[0064] Next, with reference to the attached FIG. 5, a preferred embodiment of the device of the invention is explained, applied to the recovery of a component gaseous substance from the inlet gas flow to the invention.

[0065] An inlet gas flow (1), mainly coming from fossil fuel combustion systems for obtaining primary energy, enters module 1 for the analysis thereof, modification in pressure, temperature and content in other greenhouse gases, impurities and water vapor. This flow (1) is mobilized from the installation in which it is generated by an impulsion system (2) and is led by means of a system of pipes for the inlet and treatment thereof in module 1, constituting the gas flow (3) the characteristics of which are similar to those of the flow (1), but with a constant flow rate in accordance with the features of the control system (45) of the invention.

[0066] The flow (3) has the following concentrations: CO.sub.2 (1%-25%), water vapor (0%-25%), O.sub.2 (0%-35%) and other, N.sub.2, Ar, other greenhouse gases, unburned substances, ashes, etc., in accordance with the features of the previous combustion installation. The temperature range is between 60° C. and 800° C. and pressure is slightly above atmospheric pressure. The control system (45) depending on the characteristics of the flow (1) will manage the equipment of module 1 and the operation thereof in order to optimize the operation of the system as a whole.

[0067] The gas flow (3) is treated in a first group of gas exchangers (4) in order to reach a temperature of around 40° C. or less. The first group of exchangers uses water, air or any fluid (i) in order to cool the flow (3), obtaining an outlet coolant flow (iii) in accordance with the legal limits for the treatment or evacuation to the outside thereof.

[0068] Due to the features of the cooling process of the flow (3), the excess water present condenses, together with a portion of the greenhouse gases, unburned substances, ashes and other unwanted components, constituting the flow (6) of water to be subsequently treated. The outlet flow from this group of exchangers (5), at a temperature of around 40° C. or lower, is semi-dry with water content in saturation in accordance with the temperature thereof.

[0069] This gas flow is joined by the gas flow (21) coming from module 2, which will be explained later, constituting the flow (7), which is compressed to pressures below 10 bar(g) in the compression system (8), at the outlet of which the gas flow (9) prepared for the inlet thereof into the drying system (10) is obtained.

[0070] The drying system (10) removes the water present in the flow (around 99.9%), obtaining the first outlet flow (13) from module 1 for the sending thereof to module 2. The flow (13) is modified to the temperature (20° C.-45° C.), pressure (1-9 bar(m)) and moisture (Approx. 0%) in order to optimize the adsorption process as much as possible. The drying system is cooled by a coolant fluid similar to the one used in the heat exchange group (4), using inlet (ii) and outlet (iv) flows in accordance with the legal limits for the treatment or evacuation thereof to the outside.

[0071] The drying system (10) produces a second outlet flow (11) in which the condensed water coming from the flow (9), other sulfur oxides, unburned substances, ash and other greenhouse gases are removed. The flows (6) and (11) join together and constitute the liquid flow (12) which is the second outlet flow from module 1, which is treated prior to the evacuation outside thereof or for the subsequent recovery thereof.

[0072] The operation of module 1 is adjusted by means of the control system (45) adapting the operation thereof at all times to the needs of the adsorbent material of modules 2 and 3; and the characteristics of the flow (1).

[0073] The outlet flow (13) from module 1 is injected into module 2 in the adsorption/desorption reactors (14) which are performing the adsorption process, according to the instructions of the control system (45). After passing through these adsorption/desorption reactors (14), the outlet flow of each one (15) is directed to a single outlet conduit from module 2 to be returned to module 1 in which, as flow (16) it is released to the outside (if it is not biologically active) or to the evacuation installation in the combustion system from which the flow (1) is initially taken.

[0074] In the other adsorption/desorption reactors which are performing the PSA desorption process, the outlet flow of the gases located inside the adsorption/desorption reactors (14) constitutes the flow (17), which has an enrichment in the selected gases for the variable separation thereof over time depending on the vacuum extraction process, going from a CO.sub.2 concentration of 0.4% to approximately 65%-85% depending on the characteristics of the flow (1).

[0075] By means of the vacuum pumps (18), the flow (17) is extracted and driven by the compressor (20) in order to favor the injection thereof as flow (21) to module 1 for the mixing thereof with the flow (5) during the first phase of the desorption process described above, ending the function thereof when the control system (45) so determines. At this point, the flow (17) becomes the flow (22) which is stored in the first buffer tank (23) of module 2. Once the maximum filling pressure is reached, the rest passes as flow (25) to the second buffer tank (26) of module 2 from which the flow (27) is obtained for the extraction thereof to the outside or for the injection thereof as inlet flow to module 3.

[0076] The flow (24) starts from the first buffer tank (23) of module 2 and is used as a pulling flow in the third phase of the PSA desorption process described above and is injected directly into the adsorption/desorption reactors (14) which are performing the desorption process.

[0077] The operation of module 2 is adjusted by means of the control system (45) adapting the operation of the active systems located in module 1 at all times to the needs of average and maximum CO.sub.2 concentration in the outlet flow from module 2 and for the purpose of optimizing the desorption process of the adsorption/desorption reactors (14) which perform the desorption process in module 2.

[0078] The outlet flow (27, 28) from module 2 before being injected into module 3 in the adsorption/desorption reactors (31) which are performing the adsorption process, according to the instructions of the control system (45), is mixed with the flow (36), constituting the flow (29), into which the flow (33) is mixed, in order to constitute the flow (30), which is the one that is finally injected as inlet flow to the adsorption/desorption reactors (31) which are performing the adsorption process in module 3. The flows (33) and (36) are explained below.

[0079] After passing through these adsorption/desorption reactors (31) the outlet flow from each adsorption/desorption reactor (32) is directed for the injection thereof to the other adsorption/desorption reactors as flow (33) for the mixture thereof with the flow (29) or it is carried by means of an outlet conduit from module 3 to be returned to module 1 in which, as flow (34) it is released to the outside (if it is not biologically active) or to the evacuation installation in the combustion system from which the flow (1) is initially taken, according to what is indicated by the control system (45) of the invention.

[0080] In the other adsorption/desorption reactors (31) which are performing the PSA desorption process, the outlet flow of the gases located inside the adsorption/desorption reactors constitutes the flow (39), which has an enrichment in the selected gases for the variable separation thereof over time depending on the vacuum extraction process, going from a CO.sub.2 concentration of 65%-85% to approximately 95%-100% depending on the characteristics of the flow (1).

[0081] By means of the vacuum pumps (38), the flow (39) is extracted and driven by the compressor (37) in order to favor the injection thereof as flow (36) to the flow (28) in order to constitute flow (29) during the first phase of the desorption process described above, ending the function thereof when the control system (45) so determines. At this point, the flow (35) becomes the flow (39) which is stored in the first buffer tank (40) of module 3. Once the maximum filling pressure is reached, the rest goes as flow (42) to the second buffer tank (43) of module 3 from which the flow (44) is obtained for the extraction thereof to the outside.

[0082] The flow (41) starts from the first buffer tank (40) of module 3 and is used as a pulling flow in the third phase of the PSA desorption process described above and is injected directly into the adsorption/desorption reactors (31) which are performing the desorption process.

[0083] The operation of module 3 is adjusted by means of the control system (45) adapting the operation of the active systems located in module 1 at all times to the needs of average and maximum CO.sub.2 concentration in the outlet flow from module 3 and for the purpose of optimizing the desorption process of the adsorption/desorption reactors which perform the desorption process in module 3.