Installation and process for co-production of dihydrogen and cement clinker

Abstract

The invention relates to a hydrogen production facility, referred to as a facility. The facility comprises an electrolyser, arranged to produce dioxygen and dihydrogen from steam, referred to as hot steam, at a temperature above 150°C, or from water, referred to as hot water, at a temperature below or equal to 90°C. The facility further comprises a clinker manufacturing unit. The facility further comprises a heat recovery unit arranged to produce, from gaseous discharges, referred to as hot gases, at a temperature above 150°C, emitted by the clinker manufacturing unit, hot steam or hot water. Figure for abstract: Figure 1

Description

Title of the invention: Installation and method for co-production of di-hydrogen and cement clinker Technical field

[0001] The present invention belongs to the field of hydrogen production.

[0002] The invention relates to a dihydrogen production plant and a method for producing dihydrogen by electrolysis of water.

[0003] The invention also relates to the field of cement production and more specifically clinker. State of the art

[0004] Processes for manufacturing dihydrogen are known in the state of the art, for example, by: - ​​gasification of coal, - steam reforming of methane, - electrolysis of water, - by enzymatic fermentation, - catalytic dissociation, or even - pyrolysis.

[0005] Except for the particular case of enzymatic fermentation, state-of-the-art processes for producing dihydrogen are energy-intensive.

[0006] Furthermore, most state-of-the-art processes rely entirely on the use of fossil and / or organic raw materials.

[0007] Furthermore, the state-of-the-art dihydrogen manufacturing processes induce, for the most part, greenhouse gas emissions.

[0008] Processes for manufacturing clinker are also known in the state of the art. Clinker, added to additives, is used, in particular, for the manufacture of cement. Clinker is obtained by heat treatment, typically at temperatures of the order of 1450°C, of ​​raw cement. The raw cement is composed of a mixture of raw materials including limestone, clay and sand.

[0009] The clinker production process is also highly energy-intensive. It requires the consumption of a large quantity of fossil fuel to ensure the firing, and in particular the calcination, of the raw cement.

[0010] In addition, the clinker and cement manufacturing processes release a significant amount of greenhouse gases, particularly carbon dioxide.

[0011] An aim of the present invention is to remedy at least one of the drawbacks of methods for producing dihydrogen of the state of the art and / or of methods of

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018] manufacture of clinker and / or cement of the state of the art. Another aim of the invention is to propose a di-hydrogen production installation: • having low energy consumption, and / or • having an energy consumption lower than the energy consumption of state-of-the-art hydrogen production facilities and / or clinker manufacturing facilities, and / or • having a limited and / or reduced environmental impact, and / or • enabling the environmental impact of clinker manufacturing to be limited and / or reduced, and / or • allowing the limitation of energy consumption in fossil and / or organic raw materials for the manufacture of clinker, and / or • to limit greenhouse gas emissions, and in particular carbon dioxide, emitted during the manufacture of clinker. Statement of the invention To this end, the invention of a hydrogen production installation, called installation, is proposed, comprising: • an electrolyser, designed to produce oxygen and hydrogen from: • steam, called hot steam, at a temperature above 150°C, or • water, called hot water, at a temperature less than or equal to 90°C, • a clinker manufacturing unit, • a heat recovery unit designed to produce, from gaseous discharges, known as hot gases, at a temperature above 150°C, emitted by the clinker manufacturing unit: • hot steam, or • hot water. The installation according to the invention can be defined as and / or is an installation for the co-production of dihydrogen and / or clinker and / or cement. Preferably, the installation is part of and / or is included in a cement plant. Preferably, the electrolyser is a solid oxide electrolyser, denoted SOEC, for “solid oxide electrolyzer cell”. Preferably, the heat recovery unit is arranged to produce hot water at a temperature: • less than or equal to 90°C, and / or • greater than or equal to 20°C. Preferably, the heat recovery unit is arranged to produce steam hot or hot water from at least part of the waste heat generated by the clinker manufacturing unit.

[0019] Thus, by exploiting the fatal heat of the clinker manufacturing unit, the installation according to the invention allows: • to limit energy consumption, in particular electricity, used for the production of dihydrogen and / or dioxygen, and / or • to reduce the environmental impact associated with the production of dihydrogen and / or dioxygen.

[0020] Preferably, the heat recovery unit, called at least one heat exchanger of the heat recovery unit, comprises at least one heat exchanger arranged to extract heat from the hot gases emitted by the clinker manufacturing unit.

[0021] Preferably, the heat recovery unit further comprises: • a hot steam production device arranged to produce hot steam from the heat extracted from the hot gases, and / or • a hot water production device arranged to produce hot water from the heat extracted from the hot gases.

[0022] According to a first improvement, the hot steam production device preferably comprises at least one heat exchanger, called at least one exchanger of the hot steam production device.

[0023] Preferably, the at least one exchanger of the hot steam production device is chosen from a thermal preheater, an evaporator and a superheater.

[0024] According to a second improvement, the hot water production device preferably comprises at least one heat exchanger, called at least one exchanger of the hot water production device.

[0025] Preferably, the at least one exchanger of the hot water production device is chosen from a thermal preheater and a superheater.

[0026] The heat recovery unit may comprise the first and / or the second improvement. The first and second improvements may be combined.

[0027] Preferably, the at least one exchanger of the hot steam production device and / or, respectively, the at least one exchanger of the hot water production device is arranged to produce or supply additional heat, preferably in addition to the heat extracted from the hot gases by the at least one heat exchanger of the heat recovery unit, for the production of hot steam and / or, respectively, hot water.

[0028] The at least one exchanger of the hot steam production device and / or the at least one exchanger of the hot water production device can be defined as being arranged to supplement or supplement the heat coming from the at least one heat exchanger of the heat recovery unit.

[0029] Preferably, the clinker manufacturing unit comprises: • a preheating unit designed to preheat raw material, known as raw cement, for the manufacture of clinker, and / or • a rotary kiln for cooking the preheated cement raw material, and

[0030] Preferably, the preheating unit is arranged upstream, relative to the path or the flow of the cement raw material in the clinker manufacturing unit, of the rotary kiln.

[0031] Clinker can be defined as raw cement, preferably preheated, cooked or clinkerized or heat-treated, and, in particular, calcined.

[0032] It can be understood by cooking of the raw cement, the heat treatment or the clinker-keristaion of the raw cement.

[0033] Preferably, the clinker manufacturing unit further comprises a unit for cooling the manufactured clinker.

[0034] Preferably, the cooling unit is arranged downstream, relative to the path or flow of the cement raw material in the clinker manufacturing unit, of the preheating unit and of the rotary kiln.

[0035] Preferably, the heat recovery unit is arranged to extract: • heat from hot gases, called fumes, from the manufacture of clinker, and / or • heat from hot gases, called reheated gases, resulting from the cooling of the manufactured clinker.

[0036] Preferably, the fumes correspond to the gases that were used to cook and preheat the cement raw material. Preferably, the fumes correspond to the gases that circulated in the rotary kiln and then in the preheating unit. Preferably, the fumes correspond to the gases that were in contact with the cement raw material during its manufacture. Preferably, the fumes correspond to the hot gases leaving, or recovered at the outlet of, the preheating unit.

[0037] Preferably, the reheated gases correspond to the gases resulting from the cooling of the manufactured clinker, or having been used to cool the manufactured clinker. Preferably, the reheated gases correspond to the hot gases having circulated in the clinker cooling unit. Preferably, the reheated gases correspond to cooling gases leaving, or recovered at the outlet, of the cooling unit.

[0038] Preferably: • at least one heat exchanger of the heat recovery unit, preferably one or more heat exchangers among the at least one heat exchanger of the heat recovery unit, is arranged to extract heat from the fumes, and / or • at least one heat exchanger from the heat recovery unit, preferably one or more heat exchangers among the at least one heat exchanger of the heat recovery unit, is arranged to extract heat from the heated gases.

[0039] Preferably, the heat recovery unit comprises at least two heat exchangers, more preferably two heat exchangers.

[0040] Preferably, the heat recovery unit comprises: • a heat exchanger, called the first heat exchanger, arranged to extract heat from the fumes, and / or • a heat exchanger, called a second heat exchanger, designed to extract heat from the heated gases.

[0041] Preferably, the heat recovery unit comprises: • several heat exchangers, called the first group of heat exchangers, arranged to extract heat from the fumes, and / or • several heat exchangers, called the second group of heat exchangers, arranged to extract heat from the heated gases.

[0042] Preferably, the installation further comprises a means for producing heating gas. Preferably, the means for producing heating gas is arranged to inject said heating gas into the rotary furnace. Preferably, the means for producing heating gas is arranged to produce, at least in part, the heating gas from dihydrogen produced by the electrolyser.

[0043] Preferably, the installation is arranged to supply, at least in part, the heating gas production means with the dihydrogen produced by the electrolyser.

[0044] Preferably, the installation is arranged so that the heating gases circulate in the rotary kiln, to bake the cement raw material, then in the preheating unit, to preheat the cement raw material.

[0045] Preferably, the fumes correspond to the heating gases having circulated in the rotary furnace then in the preheating unit, or, in other words, the heating gases after having circulated in the rotary furnace then in the preheating unit constitute the fumes.

[0046] Preferably, the installation and / or the electrolyser is arranged to supply the heating gas production means with dihydrogen produced by the electrolyser.

[0047] Preferably, supplying the heating gas production means with dihydrogen allows: • to reduce the environmental impact of clinker manufacturing, and / or • to limit energy consumption in fossil raw materials and / or organic for the manufacture of clinker.

[0048] Preferably, the installation further comprises a dihydrogen purification unit, called HPU, arranged to purify the dihydrogen produced by the electrolyser. Preferably, the heating gas production means is arranged to produce, at least in part, the heating gases from the purified dihydrogen from the HPU.

[0049] Preferably, the installation is arranged to supply, at least in part, the heating gas production means with the dihydrogen purified by the HPU.

[0050] Preferably, the installation and / or the electrolyser and / or the HPU is arranged to supply the heating gas production means with dihydrogen purified by the HPU.

[0051] Preferably, the heating gas production means is arranged to produce, at least in part, the heating gases from oxygen produced by the electrolyser.

[0052] Preferably, the installation is arranged to supply, at least in part, the heating gas production means with the oxygen produced by the electrolyser.

[0053] Preferably, the installation and / or the electrolyser is arranged to supply the heating gas production means with oxygen produced by the electrolyser.

[0054] Preferably, supplying the heating gas production means with oxygen allows: • to reduce the environmental impact of clinker manufacturing, and / or • to limit energy consumption in fossil raw materials and / or organic for the manufacture of clinker.

[0055] Preferably, the installation further comprises a dioxygen purification unit, called OPU, arranged to purify the dioxygen produced by the electrolyser; said heating gas production means being arranged to produce, at least in part, the heating gases from the purified dioxygen coming from the OPU.

[0056] Preferably, the installation is arranged to supply, at least in part, the heating gas production means with the oxygen purified by the OPU.

[0057] Preferably, the installation and / or the electrolyser and / or the OPU is arranged to supply the heating gas production means with oxygen purified by the OPU.

[0058] Preferably, the installation further comprises a unit for capturing carbon dioxide (CO2) contained in the fumes, having circulated in the heat recovery unit, to produce CO2 or CO2-enriched gas.

[0059] Preferably, the CO2 capture unit is arranged downstream, relative to the path or route of the fumes in the heat recovery unit and / or in the clinker manufacturing unit and relative to the path or route, of the heat recovery unit.

[0060] Preferably, the installation further comprises a CO2 conversion unit arranged to produce gaseous hydrocarbons (such as methanol, methane, or kerosene) from dihydrogen produced by the electrolyser and from CO2 produced by the CO2 capture unit.

[0061] Preferably, the installation and / or the electrolyser is arranged to supply the CO2 conversion unit with dihydrogen produced by the electrolyser.

[0062] Preferably, the CO2 capture installation and / or unit is arranged to supply the CO2 conversion unit with CO2 or CO2-enriched gas.

[0063] Preferably, the supply of the CO2 to dihydrogen conversion unit allows: • to limit energy consumption of fossil and / or organic raw materials for the manufacture of clinker, and / or • to limit greenhouse gas emissions, and in particular carbon dioxide, emitted for the manufacture of clinker.

[0064] According to the invention, a cement plant is also proposed comprising the installation for co-production of dihydrogen and / or clinker according to the invention.

[0065] According to the invention, a method for producing dihydrogen is also proposed. The method for producing dihydrogen, called method, comprises the steps of: • recover heat, using the heat recovery unit, from gaseous discharges, or hot gases, emitted by the clinker manufacturing unit, • produce, from the recovered heat: • hot steam, at a temperature greater than or equal to 150°C, or • hot water, at a temperature less than or equal to 90°C, • produce dihydrogen and dioxygen, using the electrolyser, from hot steam.

[0066] Preferably, the method further comprises the step of manufacturing clinker using the clinker manufacturing unit.

[0067] The process can be defined as a process for the co-production of clinker and dihydrogen and / or dioxygen.

[0068] Preferably, the production method according to the invention is implemented by the installation for producing dihydrogen and / or clinker and / or cement according to the invention.

[0069] Preferably, the hydrogen production plant according to the invention is suitable, more preferably is particularly suitable, more preferably is designed and particularly advantageously is specially designed, for implementing the hydrogen production method according to the invention.

[0070] Thus, any characteristic of the installation according to the invention can be directly transposed to the method according to the invention and vice versa. Brief description of the FIGURES

[0071] The invention will be better understood on reading the description which follows, given solely by way of non-limiting example and made with reference to the appended drawings in which: - [Fig.l] is a schematic representation of a non-limiting exemplary embodiment of a hydrogen production installation according to the invention, - FIGURES 2 to 4 are schematic representations of non-limiting examples of advantageous improvements to the embodiment of the production installation illustrated in [Fig.l].

[0072] It is understood that the embodiments which will be described below are in no way limiting. In particular, it will be possible to imagine variants of the invention comprising only a selection of characteristics described below isolated from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. This selection comprises at least one preferably functional characteristic without structural details, or with only a part of the structural details if it is this part which is only sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art.

[0073] In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view.

[0074] In the figures and in the remainder of the description, the elements common to several figures retain the same reference. Detailed description of the FIGURES

[0075] Dihydrogen can be produced by electrolysis of water. This process of producing dihydrogen is carried out using water and electricity. The state of the art includes: alkaline electrolysis, proton exchange membranes and solid oxide electrolysers.

[0076] [Fig.l] is a schematic representation of a non-limiting exemplary embodiment of a hydrogen production installation 1 according to the invention.

[0077] The hydrogen production installation 1, referred to as installation 1 in the remainder of this description, comprises a clinker manufacturing unit 6, referred to as CMU 6 in the remainder of this description.

[0078] According to a first non-limiting embodiment, the installation 1 further comprises a heat recovery unit 7, called HRU 7 in the remainder of this description, arranged to produce hot steam 5, at a temperature greater than or equal to 150°C, from gaseous discharges 8, 9, called hot gases 8, 9, at a temperature greater than 150°C, issued by CMU 6.

[0079] The installation 1 further comprises an electrolyser 2, arranged to produce dioxygen 3 and dihydrogen 4 from the hot steam 5 produced by the HRU 7. According to the embodiment presented, the electrolyser 2 is a high-temperature electrolyser. By way of non-limiting example, the electrolyser is a solid oxide electrolyser 2, called SOEC 2.

[0080] The hot steam 5 is therefore produced from fatal heat coming from the CMU 6. The hot steam 5 produced by or leaving the HRU 7 feeds the SOEC 2 with, optionally, a gas sweep 28 such as air.

[0081] Thus, the invention makes it possible, by means of the HRU 7, to recover, at least in part, the fatal heat coming from the CMU 6 to produce hot steam 5 which will then be used to produce dihydrogen 4 and dioxygen 3. Advantageously, the invention makes it possible to co-produce both dihydrogen 4, dioxygen 3, or gas enriched in dioxygen 3, and clinker 14.

[0082] The invention makes it possible to limit the energy consumption, in particular electricity, used for the production of dihydrogen and / or dioxygen by exploiting the fatal heat coming from the CMU 6.

[0083] The invention also makes it possible to reduce the environmental impact associated with the production of dihydrogen and / or dioxygen by exploiting the fatal heat coming from the CMU 6.

[0084] As known to those skilled in the art, the SOEC 2 comprises a reaction zone where the electrolysis of water leads to the production of dioxygen 3 and dihydrogen 4. In practice, the reaction zone is in the form of unit cells for electrolysis of solid oxides composed of an anode, an electrolyte and a cathode.

[0085] The oxygen flow 3 is formed on the anode side and can be transported by the optional gas sweep 28. The hydrogen flow 3 is formed at the cathode and leaves the electrolysis cell with any unreacted water.

[0086] The SOEC 2 further comprises a set of elements or devices (additional or auxiliary) ensuring the integration of useful heat and the transport of fluids. The set of elements or devices (additional or auxiliary) may comprise, by way of non-limiting examples, a supply / effluent heat exchanger, a heat pump, a compressor and / or an ejector.

[0087] It is known from the state of the art that the production of clinker is carried out by heat treatment, typically at a temperature close to 1450°C, of ​​raw cement.

[0088] According to the embodiment illustrated in [Fig.l], the CMU 6 comprises a preheating unit 601 (or preheating tower 601), denoted PHT 601, arranged to pre heating the cement raw material 13 and a rotary kiln 602 for firing the preheated cement raw material 13. The heat treatment of the cement raw material 13 includes preheating and firing the cement raw material 13. Thus, the heat treatment begins in the PHT 601 and continues and ends in the rotary kiln 602.

[0089] Preferably but not limitingly, the PHT 601 may be a preheating tower 601. For example, the PHT 601 may be a cyclone preheating tower.

[0090] The installation 1 comprises a heating gas production means 17, denoted HGP 17, arranged to inject heating gases 16 into the rotary kiln 602. The HGP 17 is arranged to produce the heating gases 16 from carbonaceous fuels, such as methane or coal. The heating gases 16 have the effect of cooking and preheating the raw cement 13 in the CMU 6.

[0091] The HGP 17 is located downstream, relative to the path or the route of the cement raw material 13 in the CMU 6, of the PHT 601 and of the rotary kiln 602. Thus, the heating gases having their highest temperature come into contact with the cement raw material 13 in the rotary kiln 602 then come into contact, at a lower temperature, with the cement raw material 13 in the PHT 601.

[0092] Preferably, the HGP 17 is arranged to produce the heating gases 16, at least in part, advantageously only in part, more preferably sporadically, from carbonaceous fuels supplying the installation 1 and / or the HGP 17. In other words, the installation 1 and / or the HGP 17 is supplied, at least in part, advantageously only in part, more preferably sporadically, with external fuels, i.e. not coming from the installation 1.

[0093] The installation 1, and / or the rotary furnace 602 and / or the PHT 601, is arranged to allow the circulation of the heating gases 16 in the rotary furnace 602 then the PHT 601.

[0094] According to the embodiment illustrated in [Fig.l], the CMU 6 further comprises a cooling unit 603, denoted CC, for the manufactured clinker 14.

[0095] Once produced, the clinker 14 is cooled in the CC 603 using air 15. The air 15 used to cool the clinker 14 leaves the CC 603 in the form of hot gases 8, called reheated gas 8, at a temperature between 150 and 1300°C.

[0096] The installation 1 and / or the HGP 17 may be arranged so that a fraction, preferably all, of this reheated gas 8 is reinjected into the HGP 17. This recycling of the reheated gas makes it possible to reduce the energy consumption and the environmental impact of the production of dihydrogen. In the processes of the state of the art, this excess heat contained in the reheated gas 8, typically having a temperature of between 150 and 400°C, is released in the form of residual gas.

[0097] The heating gases 16 and the cement raw material 13 exchange heat counter-currently with the cement raw material 13 throughout the rotary kiln 602 and the PHT 601. The heating gases 16 leaving the PHT 601 are noted as fumes 9. The fumes 9 leave the PHT 601 at a temperature between 150 and 400°C.

[0098] The fumes 9 at the outlet of the PHT 601 and the reheated gases 8 at the outlet of the CC may contain solid materials such as, by way of non-limiting examples, minerals, unreacted raw materials, unreacted solid fuels, in a range between 10 mg / Nm3 and 20 g / Nm3, where mg / Nm3 and g / Nm3 are respectively milligrams per normal cubic meter and grams per normal cubic meter.

[0099] According to the embodiment illustrated in [Fig. 1], the HRU 7 is arranged to extract heat from the reheated gases 8, resulting from the cooling of the manufactured clinker 14.

[0100] The HRU 7 is alternatively, preferably also, arranged to extract heat from hot gases 9, called fumes 9, resulting from the firing of the raw cement 13.

[0101] There is nothing to prevent the HRU 7 from being arranged to extract heat only from the reheated gases 8 or only from the fumes 9. However, in order to effectively limit energy consumption and further reduce the environmental impact associated with the production of dihydrogen 4 and / or dioxygen 3, the HRU 7 is preferably arranged to extract heat from the reheated gases 8 and from the fumes 9.

[0102] According to the embodiment illustrated in [Fig.l], the HRU 7 comprises at least one heat exchanger 10, 11, called heat exchanger 10, 11 of the HRU 7. The at least one heat exchanger 10, 11 of the HUR 7 is arranged to extract heat from the hot gases 8, 9. A person skilled in the art knows heat exchangers (or thermal exchangers) and will be able to choose the appropriate type of exchanger according to his needs and the specific case. For information purposes, the exchanger 10, 11 may be a heat exchanger of the economizer-recuperator type, for example using a tube and fin, tube and shell or plate exchanger technology.

[0103] The HRU 7 further comprises a hot steam production device 18. The steam production device 18 is arranged to produce the hot steam 5 from the heat extracted from the hot gases 8, 9. A person skilled in the art knows steam production devices and will be able to choose the type of steam production device suitable according to his needs and the specific case.

[0104] Preferably, the steam production device 18 comprises at least one heat exchanger, for example a single exchanger, preferably several heat exchangers, called exchangers of the steam production device 18. Preferably, the at least one heat exchanger of the steam production device 18 is chosen, for information purposes, from: a thermal preheater, an evaporator, and a superheater, for example using a shell and tube exchanger technology, or plate exchanger.

[0105] The at least one heat exchanger of the steam production device 18 is arranged to produce, or supply to the steam production device 18, additional heat supplementing or adding to the heat produced or extracted, from the hot gases 8, 9, by the at least one heat exchanger 10, 11 of the HRU 7.

[0106] By way of non-limiting example, the at least one exchanger of the steam production device 18 is arranged to provide additional heat to the steam production device 18 from an energy source other than the hot gases 8, 9. The energy source, other than the hot gases 8, 9, may come from the installation 1, for example dihydrogen 4 or dioxygen 3 produced by the installation 1. The energy source, other than the hot gases 8, 9, may be an energy source external to the installation 1, for example energy coming from a gas or electricity supply network or from external fuels.

[0107] The HRU 7 comprises at least one heat exchanger 10, advantageously several heat exchangers 10, called exchanger(s) 10 of the HRU 7, arranged to extract heat from the fumes 9.

[0108] The HRU7 alternatively comprises, preferably also, at least one heat exchanger 11, advantageously several heat exchangers 11, called exchanger(s) 11 of the HRU 7, arranged to extract heat from the heated gases 8.

[0109] As described above, there is nothing to prevent the HRU 7 from comprising a single heat exchanger 11 arranged to extract heat from the reheated gases 8 or a single heat exchanger 10 arranged to extract heat from the fumes 9. However, in order to effectively reduce energy consumption and further reduce the environmental impact associated with the production of dihydrogen and / or dioxygen, the HRU 7 preferably comprises at least one heat exchanger 11 arranged to extract heat from the reheated gases 8 and at least one heat exchanger 10 arranged to extract heat from the fumes 9.

[0110] The HRU 7 comprises a network 25 arranged to allow the circulation of a heat transfer fluid (such as for example water or oil) between the at least one heat exchanger 10, 11, and the steam production device 18.

[0111] The heat transferred to the water to produce the hot steam 5 is obtained by using the intermediate heat transfer fluid circulating in the network 25, such as, for example, water or thermal oil, or directly in a device (not shown) allowing heat transfer between the flows 9, 8 and the water.

[0112] By way of non-limiting examples, the installation 1 may comprise a water treatment unit. The water treatment unit is arranged to treat and purify water supplying the installation 1, i.e. water coming from the battery limits ex outside the battery limits, or "OSBL" for "outside the battery limits", and / or water from the SOEC 2, in particular water vapor, from the SOEC 2, which would not have reacted in the SOEC 2 during the electrolysis step. The water treatment unit is further arranged so that the treated water has a conductivity and an ion and particle content suitable for supplying the HRU 7, or the network 25. The HRU 7, or the network 25, can therefore be supplied, in whole or in part, with treated water from the water treatment unit.

[0113] The HRU 7, preferably the steam production device 18, is arranged to produce the hot steam 5 from, in addition, the treated water and / or, possibly, using electricity which may come from the network and / or from an accumulator.

[0114] In the state of the art, the heating gases used for the thermal treatment of the cement raw material are exclusively derived from the combustion of carbonaceous fuels, such as methane or coal, with air.

[0115] With reference to [Fig.2], an improvement, called a first improvement, of the installation 1 according to the embodiment presented in [Fig.l] is illustrated. The HGP 17 is arranged to produce, at least in part, the heating gases 16 from di-hydrogen 4 produced by the SOEC 2. The dihydrogen 4 feeds the HGP 17 as fuel. The dihydrogen 4 can feed the HGP 17 in addition, it can for example be mixed with a carbon fuel, for example methane or coal, or as a substitute for such a carbon fuel.

[0116] Still with reference to the first improvement of the installation 1 illustrated in [Fig.2], the installation 1 comprises a dihydrogen purification unit 19, called HPU 19. The HPU 19 is arranged to purify the dihydrogen 4 produced by the SOEC 2. The dihydrogen 4 produced by the SOEC 2 feeds the HPU 19. The HGP 17 is arranged to produce, at least in part, the heating gases (16) from, in addition, the purified dihydrogen 401 coming from the HPU 19. The purified dihydrogen 401 feeds, in whole or in part, the HGP 17. In other words, the purified dihydrogen 401 feeds the HGP 17 in addition, it can for example be mixed with carbon fuel, or as a substitute for such carbon fuel.

[0117] In addition to being arranged to purify the dihydrogen produced by the SOEC 2, the HPU 19 can also be arranged to compress the purified dihydrogen 401. The compression makes it possible to reach a suitable pressure both for the purification process and for the storage, in a suitable gas storage tank 26, of the dihydrogen 4. If the storage pressure of the dihydrogen 4 is higher than the purification pressure, several compression stages can be provided.

[0118] The first improvement of the installation 1 makes it possible to reduce the energy and / or raw material consumption, in particular the consumption of HGP 17, for the manufacture of clinker.

[0119] The first improvement of installation 1 also makes it possible to reduce the environmental impact, including greenhouse gas emissions, for the manufacture of clinker.

[0120] With reference to [Fig. 3], an improvement, called a second improvement, of the installation 1 according to the embodiment presented in [Fig. 1] is illustrated. The HGP 17 is arranged to produce, at least in part, the heating gases 16 from dioxygen 3, or a gas enriched in dioxygen 3, produced by the SOEC 2. The dioxygen 3, or the gas enriched in dioxygen 3, feeds the HGP 17 as an oxidant. The dioxygen 3, or the gas enriched in dioxygen 3 can feed the HGP 17 in addition, it can for example be mixed with the oxidant, preferably air according to the embodiment, or as a substitute for the oxidant.

[0121] Still with reference to the second improvement of the installation 1 illustrated in [Fig. 3], the installation 1 comprises a dioxygen purification unit 20, called GPU 20. The OPU 20 is arranged to purify the dioxygen 3, or the gas enriched in dioxygen 3, produced by the SOEC 2. The dioxygen 3, or the gas enriched in dioxygen 3, produced by the SOEC 2 feeds the OPU 20. The HGP 17 is arranged to produce, at least in part, the heating gases 16 from the purified dioxygen 301 coming from the OPU 20. The purified dioxygen 301 feeds, in whole or in part, the HGP 17. In other words, the purified dioxygen 301 feeds the HGP 17 in addition, it can for example be mixed with the oxidant, or in substitution for the oxidant.

[0122] Thus, according to the second improvement, the higher the oxygen content of the oxidant, the more the heating efficiency is improved.

[0123] The second improvement of the installation 1 makes it possible to reduce the energy and / or raw material consumption, in particular the consumption of HGP 17, for the manufacture of clinker.

[0124] The second improvement of installation 1 also makes it possible to reduce the environmental impact, including greenhouse gas emissions, for the manufacture of clinker.

[0125] In the state of the art, the combustion of carbon fuels, in particular fossil fuels, for the production of heat required for the thermal treatment of the cement raw material, results in the direct and significant emission of carbon dioxide (CO2).

[0126] One of the main chemical reactions responsible for direct CO2 emissions during clinker production is the decarbonation of calcium carbonate to produce calcium oxide.

[0127] With reference to [Fig.4], an improvement, called the third improvement, of the installation 1 according to the embodiment shown in [Fig.1] is illustrated. The installation 1 further comprises a CO2 capture unit 21, called CTU 21, contained in the fumes 9, having circulated in the HRU 7, to produce CO2 22 or gas 22 enriched in CO2.

[0128] The third improvement of installation 1 therefore makes it possible to limit the environmental impact, including direct greenhouse gas emissions, for the manufacture of clinker 14 by further limiting the quantity of CO2 contained in the gases released into the atmosphere.

[0129] CO2 capture may be based on one or a combination of the following processes or technologies: adsorption, absorption, membrane filtration or distillation. The main energy requirement of the CTU 21 concerns the regeneration step, during which pure CO2 is released and the solvent or sorbent is regenerated. The energy required to carry out this step may be extracted at the outlet of the HRU 7 after having carried out the generation of water vapor for the SOEC 2.

[0130] Preferably but not limitingly, the installation 1 may comprise, preferably upstream of the CTU 21, a smoke treatment device 9, such as a suitable particle filtration system (for example an electrostatic precipitator), to eliminate the particles and / or dust from the smoke 9.

[0131] Preferably but not limitingly, the installation 1 may comprise, preferably upstream of the CTU 21, a smoke treatment device 9 arranged to eliminate sulfur oxides (SOX), nitrogen oxides (NOX) and acid gases.

[0132] Still with reference to the third improvement of the installation 1 illustrated in [Fig.4], the installation 1 further comprises a CO2 conversion unit 23, denoted CCU 23, arranged to produce gaseous hydrocarbons 24 from dihydrogen 4 produced by the SOEC 2 and from CO2 22, or from the gas 22 enriched in CO2, produced by the CTU 21.

[0133] Dihydrogen 4 and CO2, originating from CTU 21, are used as reactants in CCU 23. The conversion of CO2 by CCU 23 could, for example, comprise one or the combination of the following reactions such as, for example, the reversed water gas reaction, the synthesis of oxygenated carbon compounds, preferably of compounds comprising a single carbon atom, (for example methanol, formaldehyde or formic acid), methanation (for the synthesis of methane), Fischer-Tropsch reactions (for obtaining hydrocarbons).

[0134] The combination of the third improvement with the second improvement of installation 1 allows: • to limit the environmental impact, including direct greenhouse gas emissions, for the manufacture of clinker 14 and for the manufacture of dihydrogen 4, • to reduce energy consumption and / or raw materials for hydrogen production 4 and for the manufacture of clinker 14.

[0135] Indeed, the use of purified dioxygen 301, or gas enriched in dioxygen 301, promotes oxycombustion and therefore the production of fumes 9 comprising a high CO2 level. In addition, oxycombustion allows the discharge of gases having a small quantity of nitrogen oxides. Thus, the high concentration of CO2 has the effect of promoting the conversion of CO2 into carbon compounds (in particular into fuel) which can be recovered and used directly on the installation 1. Oxycombustion also makes it possible to reduce the quantity of gaseous discharges with a high environmental impact.

[0136] The first, second and third improvements of installation 1 can be combined with each other. However, there is no requirement to combine the improvements and each of the improvements can be considered individually.

[0137] According to a second embodiment, the HRU 7 is arranged to produce hot water 5, at a temperature less than or equal to 90°C, from gaseous discharges 8, 9, called hot gases 8, 9, at a temperature greater than 150°C, emitted by the CMU 6.

[0138] The second embodiment is not exclusive of the first embodiment. The first and second embodiments may be combined or implemented jointly or alternatively. In other words, the HRU 7 may be arranged to produce hot steam 5 and / or hot water 5.

[0139] Only the HRU 7 presents differences between the first and second embodiments.

[0140] According to the second embodiment, the HRU 7 comprises, in addition to or as a substitute for the hot steam production device 18 according to the first embodiment, a hot water production device 18. The hot water production device 18 is arranged to produce hot water 5 from the heat extracted from the hot gases 8, 9. A person skilled in the art knows hot water production devices and will be able to choose the type of steam production device suitable according to his needs and the specific case.

[0141] Preferably, the hot water production device 18 comprises at least one heat exchanger, for example a single exchanger, preferably several heat exchangers, called exchangers of the hot water production device 18. Preferably, the at least one heat exchanger of the hot water production device 18 is chosen, for information purposes, from: a thermal preheater and a superheater, for example using a shell and tube exchanger technology, or a plate exchanger technology.

[0142] The at least one heat exchanger of the hot water production device 18 is arranged to produce, or supply to the hot water production device 18, additional heat supplementing or adding to the heat produced or extracted, from the hot gases 8, 9, by the at least one heat exchanger 10, 11 of the HRU 7.

[0143] By way of non-limiting example, the at least one exchanger of the hot water production device 18 is arranged to provide additional heat to the hot water production device 18 from an energy source other than the hot gases 8, 9. The energy source, other than the hot gases 8, 9, may come from the installation 1, for example dihydrogen 4 or dioxygen 3 produced by the installation 1. The energy source, other than the hot gases 8, 9, may be an energy source external to the installation 1, for example energy from a gas or electricity supply network or from external fuels.

[0144] The invention does not aim to achieve all of the objectives described in the application. The invention aims to achieve at least one of the objectives presented in the application, and, in particular, at least one of the objectives relating to the embodiment illustrated in [Fig.l].

[0145] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention.

[0146] Thus, in variants which can be combined with each other of the embodiments previously described: • CMU 6 may be included in or be part of a cement plant, and / or • cement is obtained from clinker 6 and additives, and / or • according to the first embodiment, the HRU 7 is arranged to produce hot steam 5, at a temperature greater than or equal to 150°C, • according to the second embodiment, the HRU 7 is arranged to produce hot water 5, at a temperature less than or equal to 90°C, • according to the second embodiment, the HRU 7 is arranged to produce hot water 5, at a temperature greater than or equal to 20°C, • the installation 1 comprises means for flowing hot gases 8, 9 from the CMU 6 to the HRU 7, and / or • the water treatment unit is arranged to further treat and purify water streams recovered from the OPU 20 and / or water streams recovered from the HPU 19 so that the treated water reaches a conductivity and ion and particle content suitable for feeding the HRU 7, and / or • by way of non-limiting examples, the HRU 7 may further comprise an economizer, one or more particle filters, a fan, a water heating system, for example electric, a water deaerator, a water vaporizer, a superheater, a heat storage device, a heat pump and / or an electricity storage means, for example one or more accumulators, and / or • the installation 1 may comprise a tank 26 and be arranged to store purified dihydrogen 401 from HPU 19, and / or the installation 1 may comprise a tank 27 and be arranged to store the purified dihydrogen 301 coming from the OPU 20, and / or the installation 1 may include, in addition to or as an alternative to the OPU 20, an air separation unit, denoted ASU, and / or dioxygen 3, or dioxygen 3-enriched gas, may be mixed with air and delivered to the ASU to produce purified dioxygen, and / or the ASU and OPU 20 allow for the separation or removal of impurities such as, but not limited to, water, nitrogen, argon, carbon monoxide and nitrogen dioxide, and / or the ASU and the OPU 20 may be arranged to purify dioxygen 3, or gas enriched in dioxygen 3, based on one of the following processes or technologies: adsorption, absorption, membrane separation, distillation or conversion.

Claims

Claims

1. Hydrogen production installation (1), said installation, comprising: - an electrolyser (2), arranged to produce dioxygen (3) and dihydrogen (4) from: • steam (5), called hot steam, at a temperature above 150°C, or • water (5), called hot water, at a temperature less than or equal to 90°C, - a clinker manufacturing unit (6), - a heat recovery unit (7) arranged to produce, from gaseous discharges (8, 9), called hot gases, at a temperature above 150°C, emitted by the clinker manufacturing unit (6): • hot steam, or • hot water.

2. Installation (1) according to claim 1, in which the heat recovery unit (7) comprises: - at least one heat exchanger (10, 11), called at least one heat exchanger of the heat recovery unit, said at least one heat exchanger of the heat recovery unit being arranged to extract heat from the hot gases (8, 9) emitted by the clinker manufacturing unit (6), and - a hot steam production device (18) arranged to produce the hot steam (5) from the heat extracted from the hot gases (8, 9), and / or - a hot water production device (18) arranged to produce hot water (5) from the heat extracted from the hot gases (8, 9).

3. Installation (1) according to the preceding claim, in which the hot steam production device (18) comprises at least one heat exchanger, said at least one exchanger of the hot steam production device, among a thermal preheater, an evaporator and a superheater.

4. Installation (1) according to claim 2, in which the hot water production device (18) comprises at least one heat exchanger, said at least one exchanger of the hot water production device, among a thermal preheater and a superheater.

5. Installation (1) according to any one of the preceding claims, in which the clinker manufacturing unit (6) comprises: - a preheating unit (601) arranged to preheat raw material (13), called cement raw material, for the manufacture of clinker (14), - a rotary kiln (602) for firing the preheated cement raw material,

6. Installation (1) according to the preceding claim, in which the heat recovery unit (7) is arranged to extract heat from hot gases (9), called fumes (9), resulting from the manufacture of the clinker (14).

7. Installation (1) according to the preceding claim taken in combination with claim 2, in which at least one exchanger (10) of the heat recovery unit (7) is arranged to extract heat from the fumes (9).

8. Installation (1) according to any one of the preceding claims, in which the clinker manufacturing unit (6) further comprises a cooling unit (603) of the manufactured clinker (14).

9. Installation (1) according to the preceding claim, in which the heat recovery unit (7) is arranged to extract heat from hot gases (8), called reheated gases (8), resulting from the cooling of the manufactured clinker (14).

10. Installation (1) according to the preceding claim taken in combination with claim 2, in which at least one heat exchanger (11) of the heat recovery unit (7) is arranged to extract heat from the heated gases (8).

11. Installation (1) according to claim 5, or according to any one of claims 6 to 10 taken in combination with claim 5, further comprising heating gas production means (17); said heating gas production means being arranged to produce, at least in part, said heating gases (16) from di-hydrogen (4) produced by the electrolyser (2).

12. Installation (1) according to the preceding claim, further comprising a dihydrogen purification unit (19), called HPU, arranged to purify the dihydrogen (4) produced by the electrolyser (2); the heating gas production means (17) being arranged to produce, at least in part, the heating gases (16) from the purified dihydrogen (401) coming from the HPU.

13. Installation (1) according to claim 5, or according to any one of claims 6 to 10 taken in combination with claim 5, further comprising a heating gas production means (17); said heating gas production means being arranged to produce, at least in part, the heating gases (16) from oxygen (3) produced by the electrolyser (2).

14. Installation (1) according to the preceding claim, further comprising a dioxygen purification unit (20), called OPU, arranged to purify the dioxygen (3) produced by the electrolyser (2); said heating gas production means (17) being arranged to produce, at least in part, the heating gases (16) from the purified dioxygen (301) coming from the OPU.

15. Installation (1) according to claim 6, or according to any one of claims 7 to 14 taken in combination with claim 6, further comprising a unit for capturing carbon dioxide (CO2) (21) contained in the fumes (9), having circulated in the heat recovery unit (7), to produce CO2 (22) or gas (22) enriched in CO2.

16. Installation (1) according to the preceding claim, further comprising a CO2 conversion unit (23) arranged to produce gaseous hydrocarbons (24) from dihydrogen (4) produced by the electrolyser (2) and from CO2 (22) produced by the CO2 capture unit (21).

17. A method for producing dihydrogen, comprising the steps of: - recovering heat, by means of a heat recovery unit (7), from gaseous discharges (8, 9), called hot gases, emitted by a clinker manufacturing unit (6), - produce, from the recovered heat: • steam (5), called hot steam, at a temperature above 150°C, or • water (5), called hot water, at a temperature less than or equal to 90°C, - produce dihydrogen (4) and dioxygen (3), by means of an electrolyser, from the hot steam.

18. A method according to the preceding claim, further comprising the step of manufacturing clinker (14) by means of a clinker manufacturing unit (6).

Images