EP2212241A2

EP2212241A2 - Method and system for processing gaseous effluents for independently producing h2 and co

Info

Publication number: EP2212241A2
Application number: EP08806007A
Authority: EP
Inventors: Raymond Guyomarc'h
Original assignee: Bio3D Applications
Current assignee: Bio3D Applications
Priority date: 2007-06-15
Filing date: 2008-06-16
Publication date: 2010-08-04
Also published as: CA2690743A1; US20110165056A1; FR2917399A1; WO2009004239A3; WO2009004239A2; RU2010101050A; JP2010531214A

Abstract

The invention relates to a method for processing a first gaseous effluent (11) essentially containing carbon dioxide (CO2) and a second gaseous effluent (21) essentially containing stem (H2O), wherein said method comprises the following steps: generating a first gaseous flow (12) containing carbon monoxide by passing said first gaseous effluent (11) through a first oxidation-reduction layer of a reactive material (101) including high-temperature carbon elements; generating a second gaseous flow (22) essentially containing dihydrogen (H2) by passing said second gaseous flow (21) through a second oxidation-reduction layer of a reactive material (201) including high-temperature carbon elements; and the valorisation of at least one of the first and second gaseous flows (12, 22). The method can further include the synthesis of hydrocarbon molecules (HC) from the dihydrogen (H2) and the carbon monoxide (CO). The invention further relates to a system implementing the method of the invention.

Description

"Process and system for treating gaseous effluents to independently produce H2 and CO"

The present invention relates to a method for treating gaseous effluents. It also relates to a system implementing the method according to the invention.

The field of the invention is the field of the treatment of gaseous effluents. More particularly, the invention relates to the production of carbon monoxide (CO) and hydrogen (H ₂ ) molecules in constant, independent, concomitant and controlled fluxes, from a fuel containing carbon elements, in particular plant biomass, and gaseous effluents. The invention can be applied in a large majority of industrial field.

There are currently processes and systems for producing carbon monoxide (CO) and hydrogen (H ₂ ) by thermochemical reaction of plant biomass, such as biomass gasification processes. These methods make it possible to carry out the gasification of the biomass by treating the biomass with a hot and humid gas stream in a treatment reactor. The biomass in the reactor is pyrolyzed and gasified and the gas stream recovered after gasification of the biomass is charged with gaseous components such as hydrogen carbon monoxide and hydrocarbon compounds that have formed during the gasification of the biomass. biomass. These gaseous components are all mixed and it is then necessary to separate them if we want to exploit them separately. A disadvantage of the gasification processes is that it is not possible to separately control the proportions of the gaseous components present in the gas stream recovered after treatment. Thus, for example, it is not possible to control the proportions of hydrogen and carbon monoxide produced by the gasification of biomass. In addition, these processes make it possible to produce hydrogen and carbon monoxide only mixed. Moreover, the currently known gasification processes and systems do not make it possible to treat a gaseous effluent containing CO ₂ from sources other than the process itself.

An object of the invention is to provide a method and a system for producing H ₂ and CO to overcome the disadvantages of the systems of the state of the art.

Another object of the invention is to provide a method and a system for producing H ₂ and CO separately.

Another object of the invention is to provide a method and system for producing H ₂ and CO to control the amount of H ₂ produced independently of the amount of CO produced.

The invention thus proposes a method of treating a first gaseous effluent essentially comprising carbon dioxide (CO ₂ ) and a second gaseous effluent comprising essentially water vapor (H ₂ O), said process comprising the following steps: - generation of a first gaseous stream comprising carbon monoxide (CO) by passing said first gaseous effluent through a first layer of oxidation-reducing reactive material comprising carbon elements at high temperature, - generating a second gaseous stream essentially comprising dihydrogen (H ₂ ) by passing said second gaseous effluent through a second reactive material redox layer comprising elements of carbon at high temperature, and - upgrading at least one of the first and second gas stream.

Thus, the process according to the invention makes it possible to separately produce hydrogen and carbon monoxide. Thanks to the process according to the invention, the proportions of hydrogen produced and carbon monoxide produced can be controlled separately. In addition, carbon monoxide and hydrogen are not mixed and make up two separate gas streams that are separately recoverable. In the continuation of the request we will use the chemical formulas to facilitate the reading. The process according to the invention comprises, during the passage of the first gaseous effluent containing essentially CO ₂ , through the first layer containing carbon elements at high temperature: a reduction of the CO ₂ molecules in the presence of the carbon elements at high temperature. This reduction produces carbon monoxide (CO) molecules; and

an oxidation of at least a portion of the carbon elements at high temperature. This oxidation produces CO molecules. Thus, the first gas stream obtained from the first gaseous effluent essentially comprises CO molecules. According to the proof established by physicist BOUDOUARD on the equilibria of carbon oxides CO ₂ and CO, this first gas flow should contain only molecules of CO. Advantageously, the process according to the invention may comprise a heat exchange of at least one of the first and second gaseous flows with a heat transfer stream, this gaseous flow yielding at least a portion of its thermal energy to the heat transfer stream. In particular, the first and second gaseous streams can yield at least a portion of their heat energy to the heat transfer stream.

In addition, the heat transfer stream may comprise water. In a particular version of the invention the heat transfer stream may be water in the gaseous or liquid state. The thermal exchange of water with the first and the second gas stream then produces a third gas stream comprising high temperature water vapor.

Advantageously, at least a portion of the water vapor contained in the second gaseous effluent may come from the third gaseous stream containing essentially water vapor. Indeed, part of the second gaseous effluent can come from a facility producing a gaseous effluent containing water vapor. Part of the third gas stream may be mixed with the gaseous effluent from this plant to obtain the second gaseous effluent.

In a particular version of the invention, the process may be started with a second gaseous effluent containing produced water by another device, system or installation requiring or not an energy supply. Once the process has started, the third gas stream may be the second gaseous effluent so that the second gaseous effluent is completely produced by the process according to the invention, and the process according to the invention is then self-sufficient in thermal energy to produce the second gaseous effluent. second gaseous effluent.

The method according to the invention further comprises, during the passage of the second gaseous effluent, essentially containing water vapor (H ₂ O), through the second layer containing carbon elements at high temperature:

a reduction of water vapor molecules in the presence of said carbon elements at high temperature, said reduction producing molecules of H ₂ , and

an oxidation of at least a portion of said carbon elements at high temperature, said oxidation producing molecules of

CO;

a reduction of water vapor molecules (H ₂ O) in the presence of the CO molecules, during the final crossing of the second layer and in the post-layer zone of reactive material, in a "CO Shift" reaction producing molecules of H ₂ , and

an oxidation of at least a portion of said CO molecules, said oxidation producing CO ₂ molecules; the second gas stream essentially comprising hydrogen H ₂ and carbon dioxide CO ₂ . The method according to the invention may further comprise a step of separating the CO ₂ contained in the second gas stream, to provide a fourth gas stream essentially comprising CO ₂ and a fifth gas stream containing essentially hydrogen H ₂ .

Advantageously, at least a portion of the fourth gas stream containing essentially CO ₂ may be mixed with the first gaseous effluent. Indeed, a portion of the first gaseous effluent can come from a facility producing a gaseous effluent containing CO ₂ . Part of the fourth gas stream may be mixed with the gaseous effluent from this plant to obtain the first gaseous effluent. In a particular version of the invention, the process can be started with a first gaseous effluent containing CO ₂ produced by another device, system or installation requiring or not an energy supply. Once the process has started, the fourth gas stream may be the first gaseous effluent so that the first gaseous effluent is completely produced by the process according to the invention, and the process according to the invention is self-sufficient to generate the first gaseous effluent. .

Moreover, at least a portion of the first oxidoreductive layer is produced by combustion, in the presence of an oxidant, of a fuel composed of carbon elements under sub-stoichiometric conditions.

This solid fuel may comprise plant biomass. Indeed, plant biomass advantageously meets the criterion of solid fuel composed of carbon. In addition, plant biomass participates in the natural carbon cycle as follows. The carbon involved in the atomic composition of plant biomass comes from the essentially photosynthetic conversion of atmospheric carbon dioxide. It is therefore considered that the CO ₂ resulting from the combustion of plant biomass has a neutral effect on the problem of greenhouse gases, unlike that resulting from the combustion of fossil fuels. In addition, plant biomass is a source of renewable energy. The CO ₂ and hydrocarbon molecules are part of the eco-life cycle, the industry generates these molecules to excess thereby creating a deep imbalance that pollutes the ecosystem. These elements can be recycled directly by the process permanently, so they will no longer participate in greenhouse gases (GHG). In addition, a large majority of vegetable biomass sources, which is a renewable and cultivable raw material, can be used by the process according to the invention. Their recovery and the impact on the environment is beneficial when they are packaged for the use of the process: - simply shredded into chips or coarse chips, the arboreal biomass will be optimized by dehydration which allows the exhaustive exploitation of its energetic power.

- By roasting these shreds, by an appropriate technique that recycles the energy that is implemented, its carbon content per mass of final material is substantially increased, thus making the fuel more reactive,

- milled, dried and densified, all plant biomass will be transformed into a homogeneous, stable and calibrated solid fuel which has identical properties, regardless of the origin of the raw materials, forest and / or agricultural. A high-performance densification concentrates the carbon of the plant material up to 85% of the mass (instead of 50% of the source material) and the product of the technique can advantageously be of cylindrical shape, to favor the gravitational flows in the system. .

Roasting and / or densification improve the overall exploitation of the system, in particular by maintaining the quality of the solid fuel during storage. Plant biomass is available practically everywhere and in a profusion, its densification can be carried out on the site itself. its exploitation, as on the site of the manufacturer who installs the system implementing the method according to the invention.

The combustion of the solid fuel can be carried out under oxidant O ₂ . This oxidant can be injected in a targeted way in the heart of the first layer.

Advantageously, at least a portion of the second oxidoreductive layer is produced by transfer or recovery of at least a portion of the high temperature carbon elements of the first layer. The first layer may be at a higher location than the first layer. Moreover, the first layer may be inclined towards the second layer so that at least a portion of the high temperature carbon elements of the first layer gravitational flow from the first layer to the second layer.

According to the invention, the temperature of the first layer is greater than or equal to 1000 ^° C. and the temperature of the second layer is between 800 and 1000 ^° C. The temperatures of the first and second layers can be regulated by injection an oxidant, for example I ¹ O ₂ .

As indicated above, the method according to the invention may comprise a separation of the CO ₂ and H ₂ molecules present in the second gas stream, this separation providing a fifth gas stream essentially comprising H ₂ . CO ₂ is recyclable in CO by the first layer, it can be temporarily stored, liquid and / or gaseous to participate in the regulation and safety of the installation. It can also be marketed in liquid form to industrial operators. The deoxidation of this CO ₂ in 2 CO also allows a withdrawal of CO, which can be compensated by a supplement of CO ₂ of industrial origin, itself then removed greenhouse gases the time of a new life cycle or definitely in case of substitution of a fossil energy. Advantageously, the process according to the invention may comprise a synthesis of hydrocarbon compounds from H ₂ and CO in means such as catalysts.

Indeed, the process according to the invention makes it possible to separately obtain three gaseous streams containing CO, H ₂ and CO ₂ which can be put in buffer tanks, to be used, in any desired dosage, in any existing hydrocarbon formulations and forthcoming, in the eco-industrial space of chemistry and petrochemistry, as well as the environment and depollution.

More particularly, the invention relates to the production of fuels and liquid and gaseous fuels for synthesis, for a substitution of petroleum products and natural gas by these fuels of vegetable and renewable origin. For the synthesis of these fuels, it is the CO and H ₂ molecules that are exploited. These two gases are directed, according to the quantities and to the adequate temperature for the synthesis defined in the dedicated catalysis system. The purified gases can advantageously be heated by the reaction gases before they are cooled to the purification temperature. The thermal cycle thus defined is complete, with no losses other than those inherent to the losses of all thermal equipment and systems. The energy capacity of the hydrocarbon compounds, before the catalytic synthesis, is the maximum of the energy potential of the fuel used in the system according to the invention that can be obtained. At the exit of the catalysis, the new source of synthesized energy is recovered:

the synthetic biogas is conditioned to be stored and / or used as it is,

- liquid hydrocarbons are distilled to be stored as is and exploited,

the hydrocarbon compounds, for the production of substitute energy or of synthetic molecules, are conditioned to be stored in the state and / or used.

Furthermore, the process according to the invention carries out a purification of at least one of the first and second gaseous effluents by combustion of combustible particles present in the first gaseous effluent and / or in the second gaseous effluent during the passage of these gaseous effluents. through the first layer and / or the second layer.

According to another aspect of the invention there is provided a system for recycling a first gaseous effluent comprising essentially (CO ₂ ) and a second gaseous effluent comprising essentially water vapor (H ₂ O). The system according to the invention comprises an enclosure comprising: a first reactor comprising a first gate supporting a first reactive material redox layer comprising high temperature carbon elements, the first layer being crossed by the first layer; gaseous effluent providing a first gas stream comprising CO, and

- A second reactor comprising a second gate supporting a second reactive material redox layer comprising high temperature carbon elements, the second layer being traversed by the second gaseous effluent providing a second gas stream comprising H ₂ .

The system according to the invention further comprises means of upgrading at least one of the first and second gas streams.

Advantageously, the system according to the invention may comprise a communication opening by which the first and second reactors communicate with each other so that at least a portion of the high temperature carbon elements of the first layer pass from the first reactor to the second reactor. reactor through the communication aperture to form at least a portion of the second layer.

In addition, the first grid supporting the first layer is located at a location higher than the second grid supporting the second layer. The first gate is substantially inclined toward the second gate, the lower end of the first gate being at the communication aperture so that at least a portion of the high temperature carbon elements of the first layer flows from the first reactor to the second reactor to form the second layer. By doing so, the endothermic phase of this second layer of reactive material (if it were to be fed with cold solid fuels) was avoided which would generate oxides of carbon, which could disturb the generation of the second gas stream. In addition, the first and second grids are permeable to the first or second gas stream, each of these grids separating the reactor in which it is in a first and second zone. The first zone is located above the grid and comprises an opening for introducing the gaseous effluent into the reactor and the second zone is located below said grid and comprises an opening for extracting the gas flow. Furthermore these grids can be cooled with a heat transfer fluid, which may be water, flowing or projected in these grids. Advantageously, the first reactor may comprise an opening for introducing, on the first gate, a fuel comprising carbon elements, the first layer being produced by combustion, in the presence of an oxidant, of the fuel under sub-conditions. stoichiometric. This fuel is preferably plant biomass.

Each of the first and second reactors may further comprise means for injecting an oxidant into the reactor and more particularly to the core for the first layer of oxidation-reducing reactive material. This oxidant is firstly used to carry out the combustion, under substoichiometric conditions, of the fuel introduced into the first reactor and consequently of that which gravitates through the introduction opening into the second reactor and, on the other hand, on the other hand, to regulate the temperature of the two layers of oxidation-reducing reactive materials. The system according to the invention may further comprise means for recovering residues from each of the first and second reactors. These residues can be evacuated from each of the reactors through a discharge opening located in the bottom of the reactor and opening to at least one ashtray provided to accommodate the residues. The system according to the invention may further comprise at least one heat exchanger performing a heat exchange of at least one of said first and second streams with a heat transfer fluid.

This coolant can be water. The heat exchanger then provides a third gas stream essentially comprising high temperature water vapor. The system according to the invention may further comprise a feed circuit for at least a portion of the third gas stream in the second reactor or in the second gaseous effluent. Furthermore, the system according to the invention may comprise means for separating the different gaseous compounds from the second gas stream, comprising H ₂ and CO ₂ obtained by oxidation-reduction of the water vapor in the presence of carbon elements. high temperature. These separation means can provide a fourth gas stream essentially comprising CO ₂ and a fifth gas stream essentially comprising H ₂ .

At least a portion of the fourth gas stream can be fed into the first reactor or mixed in the first gaseous effluent by a feed circuit.

Finally, the system according to the invention may comprise means for synthesizing hydrocarbon compounds from H ₂ , CO but also CO ₂ obtained during the process according to the invention.

Other advantages and characteristics will appear on examining the detailed description of a non-limiting embodiment, and the appended drawings in which:

FIG. 1 is a schematic representation of the system according to the invention; and FIG. 2 is a schematic representation of an enclosure according to the invention comprising the first and the second reactor.

Figure 1 is a schematic representation of the system according to the invention. The system according to the invention comprises a chamber E comprising a first reactor 10 comprising a first reactive material redox layer comprising high temperature carbon elements and a second reactor 20 comprising a second reactive material oxidation reduction layer comprising carbon elements with high temperature. This reaction chamber E, comprising the two reactors 10 and 20, is shown in Figure 2 and detailed below.

The reactor 10 in the enclosure E receives biomass B to feed the reactions occurring in the reactors 10 and 20 and more particularly for producing the oxidoreductive layers in the reactors 10 and 20. The biomass B is preferably plant biomass whose calorific value has been optimized. The biomass B introduced into the first reactor 10 undergoes oxyfuel combustion under sub-stoichiometric conditions in the presence of an oxidant which is 10 ₂ . The oxygen is injected directly into the reactor 10 and possibly into the reactor 20, firstly to carry out the combustion of the biomass B and, secondly, to regulate the temperatures of the reactive material layers in the reactors 10 and 20. Oxygen can be industrial oxygen

The reactor 10 receives a first gaseous effluent 11 essentially comprising carbon dioxide CO ₂ . This gaseous effluent 11 can come, at least in part, from an external installation. In the example shown in FIG. 1, the gaseous effluent 11 is produced by recycling the different gaseous flows produced by the system according to the invention at different stages of the process according to the invention. By passing through the layer of reactive material in the reactor 10, composed of carbonaceous solid fuel in substoichiometric oxycombustion, the CO ₂ present in the first gaseous effluent 11 and that resulting from the combustion of the biomass are reduced to carbon monoxide. CO, according to the reaction defined by Boudouard:

CO ₂ + C ^ 2CO.

The conversion is integral when the reaction temperature is equal to or greater than 1000 ^° C. The CO is an industrial gas, it is the active form of the carbon entering into the synthesis catalysts. In addition, the CO obtained can participate in the synthesis of exploitable carbons in hydrocarbon molecules and generators of industrial products. The CO ₂ life cycle, present in the first gaseous effluent 11 and coming from the combustion of biomass B under oxidant O ₂ , is thus prolonged and replaces its fossil carbon equivalent, which would have contributed to greenhouse gases. . The reactor 10 outputs a first gas stream 12 essentially comprising CO.

The reactor 20 receives a second gaseous effluent 21 essentially comprising water vapor at high temperature H ₂ O. This second gaseous effluent 21 may come, at least in part, from an external installation. In the example shown in FIG. 1, the second gaseous effluent 21 is produced by energy recovery of the different gaseous flows produced by the system according to the invention at different stages of the process according to the invention. The water vapor H ₂ O found in the second gaseous effluent 21 is at a very high temperature, acquired by cooling the outgoing gases of the two reactors. The temperature of the water vapor, which passes through the dedicated reactor of the reactor vessel 1, must be between 700 and 1000 ⁰ C to be the conditions required for the deoxidation reaction. By passing through the layer of reactive material, in the reactor 20, comprising carbon elements at high temperature, greater than or equal to 1000 ^° C., the H ₂ O molecule will lose its oxygen atom in favor of a carbon atom. and / or a molecule of CO (carbon monoxide) according to the formula: C + H ₂ O -> CO + H ₂ , then

CO + H ₂ O -> CO ₂ + H ₂ ,

The reactor 20 outputs a second gas stream 22 essentially comprising H ₂ dihydrogen and carbon dioxide CO ₂ .

At the outlet of the enclosure E and more particularly of the first and second reactors 10 and 20, the first and second gas streams 12 and

22 are at high temperature. They are hardly valued at this temperature. The thermal load they hold is useful to the reaction process. It is therefore necessary to recover it.

The first gas stream 12 produced by the reactor 10 passes through a water / gas exchanger E1. In the heat exchanger E1, the first gas stream 12 comprising carbon monoxide CO will transfer its excess heat to a heat transfer fluid which, in the example represented in Figure 1 is liquid water H ₂ O _L. This heat transfer fluid is at the temperature and pressure of the distribution network or a dedicated reserve. By exchanging its thermal load, the first gas stream 12 will evaporate the water and provide a third gas stream 13 comprising essentially high temperature water vapor. The cooling of the first gas stream 12 is defined by the carbon monoxide storage set CO, located in the first gas stream 12, in a tank 14 and / or the instructions for use of this CO. This temperature may be close to the temperature of the liquid water H ₂ O _L entering the exchanger E1. The superheated steam constituting the third gas stream 13 leaving the exchanger E1 is channeled to the reactor 20 for be deoxidized as described above. The heat capacity of the first gas stream 12 is thus completely recycled and contributes to the overall efficiency of the process according to the invention. Thus, the third gas stream partly comprises the second gaseous effluent 21.

The second gas stream 22 produced by the reactor 20 goes into an exchanger E2 similar to the exchanger E1, that is to say a water / gas heat exchanger, in which the second gas stream 22, essentially comprising H ₂ and CO ₂ according to the approximate and respective proportions of 2 / 3-1 / 3, will transfer its excess heat to a coolant which, in the example shown in Figure 1, is also liquid water H ₂ O _L . This heat transfer fluid is at the temperature and pressure of the distribution network or a dedicated reserve. By exchanging its thermal load, the second gas stream 22 will evaporate the liquid water H ₂ O _L - At the outlet of the exchanger E2 there is therefore a gas stream 23 essentially comprising superheated steam which is mixed with the third gas stream 13 to be returned to the reactor 20 to be deoxidized. The assembly (gaseous flow 13 + gaseous flow 23) provided by the heat exchangers E1 and E2 make up the second gaseous effluent 21. The cooling of the second gaseous flow 22 is defined by the instruction for use and / or storage of the second flow gaseous 22, and / or the appropriate temperature for the best performance of a gas separator 24 realizing the separation of hydrogen H ₂ and carbon dioxide CO ₂ , which temperature may be close to the temperature of the liquid water entering the water. exchanger E2.

The recovery and recycling of the thermal capacities of the first and second gas streams 12 and 22 contribute to the overall efficiency of the system according to the invention and in particular to the transfer of the energy of solid biomass to molecules of "gas energy" H ₂ and CO.

The separator 24 carries out the separation of H ₂ and CO ₂ . At the outlet of the separator 24 there is therefore a fourth gas flow 25 essentially comprising carbon dioxide CO ₂ and a fifth gas stream 26 essentially comprising hydrogen H ₂

The fifth gas stream 26 essentially comprising H ₂ can be used as it is at the implantation site of the system according to the invention, for a hydrocarbon synthesis for example, and / or molecular hydrogenation, and or the production of electricity, in a fuel cell for example, and / or any industrial process using this gas. It can also be conditioned and / or liquefied on site to be stored in a tank 27 before further operation.

At least a portion of the fourth gas stream substantially comprising CO ₂ is intended to be reintroduced into the reactor to be recycled and reduced to CO, as described above. At least a portion of the fourth gas stream 25 thus composes the first gaseous effluent 11. In doing so, the reaction cycle is closed. The ratio of the energy available, by the synthesis gases, that is to say the first and the second gas stream, the energy potential of the solid fuel is maximum.

Part of the fourth gaseous flow essentially comprising CO ₂ can be liquefied so as to be stored, waiting to be used, in a tank 28 and / or to be stored as a buffer in the gaseous state, in order to regulate its operation.

The molecules H ₂ and CO can thus be produced separately, in the quantities required by use, at equal or different temperatures.

They can be exploited together, in a catalytic synthesis, or be operated separately, as both simultaneously in different applications.

In the case of direct use in a very high energy energy cogeneration system, fuel cells, combined cycle gas turbines, the first and second gas streams may be operated without molecular separation after cooling in the heat exchangers E1 and E2. The transfer of the heating value of the solid fuel to the calorific value of the synthesis gas, H ₂ and CO, is maximal. Only thermal losses, depending on the insulation used in enclosure E and peripherals, are deduced from the rate. It will then be the characteristics and qualities of the equipment, which exploits these gaseous flows 12 and 22, which will define the overall efficiency of the energy conversion.

The solid residues R of each of the reactors 10 and 20 are recovered and discharged from the reactors 10 and 20.

If H ₂ is operated as is at the site of implantation of the system, for a hydrocarbon synthesis for example, or molecular hydrogenation, or any industrial process using this gas, it will be necessary to implement a chemical separator or membrane 25 which will allow the separate management of H ₂ and CO ₂ . These materials are known and widely available.

If H ₂ is intended to be stored in the tank 27, in part or in whole, the current methods are cryogenics systems. Given the temperature / liquefaction pressure of H ₂ , the CO ₂ will be naturally liquefied during the procedure, the separation is effective.

The system according to the invention also comprises at least one catalytic module defined according to the choice of HC hydrocarbon molecules to be produced from the H ₂ and CO obtained. This catalyst module may comprise catalysts, synthesizers, reformers, or any other known system or device commonly used by the chemical and petrochemical industry.

Advantageously, the invention makes it possible to produce H ₂ and CO separately and in the desired quantity. The supply of the catalysis and reforming system is thus made as a function of the molecule to be obtained, the synthesis of all liquid and gaseous HC hydrocarbons is possible, it is the choice of the synthesis module 30 which is decisive. Advantageously according to the invention, all types of gaseous and liquid synthesis systems can be associated with the production of both H ₂ and CO molecules. These systems can coexist to be powered simultaneously. The synthesis can be plural and produce at the same time, gas and liquid fuel, as well as automotive fuel, with a maximum conversion efficiency, based on the energy initially held by the biomass and / or the reactive solid fuel.

The invention presents here two independent, concomitant and simultaneous reactions in a common enclosure E comprising two reactors 10 and 20 communicating with differentiated actions. We will now describe the enclosure E with reference to the figure

2. The enclosure E comprises the first CO ₂ reduction reactor 10 present in the first gaseous effluent 11 and the H ₂ O reduction reactor 20 present in the second gaseous effluent 21.

The first reactor 10 comprises a first layer of reactive material 101 supported by a first gate 102. The gate 102 is permeable to the reaction gases and can be cooled or not. The layer of reactive material can also be called "first thermal base". It consists of solid fuel oxycombustion, preferably plant biomass B, introduced on the grid by an introduction opening 103 in the form of chute. Biomass B can be the size of wood chips or chips / shreds of the wood industry, it can be shreds and / or sawdust and / or all vegetable matter agglomerated into pellets, briquettes, sticks, etc. It can also be silvicultural and / or agricultural biomass in the anhydrous or roasted or densified state with high carbon concentration and calibrated in cylindrical form.

In some cases and for some applications this solid fuel may be coal, peat, lignite, etc.

The biomass B present on the gate 102 is in oxyfuel combustion. This oxycombustion is made possible by injection of an oxidant, preferably I ¹ O ₂ injected into the heart of the thermal base 101 by at least one injector 104. It is the injection of I ¹ O ₂ which allows the organization of specific layers in the thickness of the first thermal base 101. The injection of O ₂ is defined to oxidize the portion (stratum) central of the first thermal base in order to generate the thermal energy necessary for all the reactions occurring at the level of the first thermal base. The upper part of the thermal base is defined by the continuous supply of fuel B, this zone is endothermic. The lower part, in direct contact with the grid 102, is defined by the Boudouard reaction, it is controlled in temperature and in molecular compositions (CO 2 / CO ratio). Its regulation is done by controlling the O ₂ injected flow rate, the control of absence of CO ₂ (most of the gaseous flow is composed of CO) and the supply of fuel.

The reactor 20 comprises a layer of reactive material 201 comprising carbon elements at high temperature. This layer 201 can also be called second thermal base. It is supported by a second gate 202 which can be cooled or not. The regulation of the temperature of the thermal base 201 can be provided by injecting oxidant O ₂ by at least one injector 204 disposed just above the thermal base 201.

The two reactors 10 and 20 are separated by a wall 203 having a communication opening C through which the reactors 10 and 20 are in communication.

The first gate 102 supporting the first thermal base 101 is substantially inclined towards the second gate 202 supporting the second thermal base 201. The end of the gate 102 closest to the gate 202 is disposed at the communication opening C The inclination of the grid 102 and the controlled oxycombustion render the central stratum of the first thermal base 101 unstable, the ignition materials gravitate downwards. The high temperature solid carbon particles, from the thermal base 101, flow by gravity on the gate 202 through the opening C to form the second thermal base 201. The gate 202 of the reactor 20 receives the flame of solid fuel from the thermal base 101 of the reactor 10 which have flowed by gravity through the opening C. These materials, which are derived from the oxy-fuel solid fuel biomass forming the first thermal base 101, are partly consumed by oxycombustion and reduced to pure carbon. The temperature of these carbon particles makes these carbon elements oxyreductive elements very reactive. The firebrands thus flow naturally through the communication C, until the reactive carbon charge, on the gate 202, covers the entire height of the communication opening C. It is the filling of the height of the second thermal base 201 which regulates the flow of the firebrands from the first thermal base 101.

The reactor 10 further comprises an inlet opening 105 of the first gaseous effluent 11, comprising the CO ₂ to be reduced in its upper part. As described above the first gaseous effluent comes at least in part from the recycling of the fourth gas stream. The CO ₂ present in the first gaseous effluent 11 is added to the CO ₂ of the oxycombustion of the solid fuel stratum. At least a portion of the CO ₂ present in the first effluent can also come from an industrial plant external to the system according to the invention. Thus, the life cycle of the carbon it contains may be prolonged, and its contribution to the greenhouse effect removed. A more or less important part of this atmospheric pollutant can be recycled in the system according to the invention, the CO resulting from the reduction of CO ₂ at the passage of the first thermal base can be reduced in a specific catalyst where it will react according to the reaction demonstrated by the physicist Boudouard: 2CO, in the presence of Nickel, exchange an atom of O in favor of a CO. This reaction is exothermic 172 kJ / mol and is at equilibrium around 400 ⁰ C, this exotherm can be recycled in the process, ie 2CO - »C + CO ₂ + 172 kJ / mol. Thus, by recycling industrial CO ₂ , which would otherwise contribute to the greenhouse effect, it is possible to lengthen the life cycle of carbon by regenerating the elements of native carbons, in virgin materials, whether structured or not, which enter the industrial cycle. substituting for fossil carbons.

The CO ₂ present in the first gas stream decomposes on passing the first thermal base comprising carbon elements at high temperature. Thus, downstream of the thermal base is obtained the first gas stream 12 essentially comprising CO. The first gas stream 12 is discharged from the reactor 10 through an evacuation opening 106 located under the first gate 102. A pipe connected to this discharge opening 106 is kept in depression by an extraction system which ensures a constant depression. in the zone of the reactor 10. The solid residues R of the first thermal base 101, such as ash, are evacuated by gravitation through a discharge opening 107 arranged in the bottom of the first reactor 10.

As described above, the second thermal base 201 is supplied with solid reagent by the communication opening C between the two reactors 10 and 20, which allows the flow of carbon at high temperature, carbon to red, from the first thermal base 101. The saturation of the second thermal base 201 is determined by the upper lip of the communication opening C. The material component of this second thermal base 201 is eminently reducing, its purpose is to deoxidize the vapor water to produce hydrogen and CO ₂ .

The upper layer of the second thermal base 201, fed continuously by the first thermal base 101, is at the temperature of the thermal base 101. This upper layer / layer is traversed by the water vapor H ₂ O, contained in the second superheated gaseous effluent 21 admitted into the reactor 20 through an inlet opening 205, located in the upper part of the reactor upstream of the second thermal base 201. A part of this water vapor H ₂ O, superheated at its deoxidation temperature, will deoxidize through the upper layer of the second thermal base 201. The deoxidation reaction

H ₂ O + C -> H ₂ + CO is endothermic. The 131 kJ / mol are provided by the thermal capacity of the upper layer of the second thermal base 201. The reaction temperature at this layer must be above 800 ^° C., if the first deoxidation reaction of H ₂ O may lower the temperature of this layer below this threshold, a injection of O ₂ 204 makes it possible to maintain the optimum reaction temperature.

The lower layer of the second thermal base 201, in direct contact with the second gate 202 of the second reactor 20, provides the second "CO Shift" reaction defined by the formula

H ₂ O + CO ₂ + CO ₂

This reaction is exothermic, 41 kJ / mol. The thermal energy released can be contained by the arrangement of a double partition, at this lower layer, in which a heat transfer fluid absorbs this thermal energy. The coolant may be water used in the exchangers E1 and E2 described above. The reaction "CO Shift" continues downstream of the gate 202 into the exchanger E2 where the exotherm of the reaction is dissipated to the heat transfer fluid thereof. Downstream of the second grid, the second gas stream is obtained

22 essentially comprising H ₂ and CO2. The reactor 20 further comprises an evacuation opening 206 making it possible to evacuate the second stream 22 from the reactor 20. This evacuation opening 206 is connected to a pipework maintained in depression by an extraction system which controls and maintains a constant depression in the reactor 20.

The solid residues R of the second thermal base 201, such as ash, are removed by gravitation through a discharge opening 207 provided in the bottom of the second reactor 20. The walls of the enclosure E are configured to be Controlled in temperature and regulated by conventional thermal means, the outer insulation of the enclosure is made in such a way as to limit thermal losses.

The walls of the enclosure E may have an interior space in which a coolant can be projected to cool the walls and recover heat energy. Advantageously, the second gas stream 21 can accumulate, in this space, additional heat capacity. The combustion in the two reactors 10 and 20 is preferably reversed, the gaseous effluents and the gas flows having a downward direction of movement in opposition to a gravitational heat flow whose natural direction is ascending. The gaseous system is thus forced by mechanical extraction, not shown, which keeps the two reactors 10 and 20 in depression. The flow organization can nevertheless be conventional, ascending in the two reactors 10 and 20, or differentiated upward flow in one of the reactors and downward flow in the other.

The system is thus suitable for at least two independent, concomitant and simultaneous reactions. The reaction in the reactor 10 thus has a triple effect: production of the thermal energy required by the system, by complete oxyfuel combustion of at least a portion of the solid fuel, - production of reagent (carbon at red at very high temperature) to enable the reaction below and supply reagent reactor 2, production of carbon monoxide CO, by the oxidation reaction: C + O ₂ → CO ₂ followed by the so-called Boudouard reaction: CO ₂ + C -> 2 CO

The second thermal base 201 of the reactor 2 is thus composed of carbon red, which has the property of being "redox". Any element and oxidized molecule that will pass through will be deoxidized by generating at least one carbon oxide CO. The system is then ready for the reduction of polluting molecules such as: SOx, NOx, Furans and Dioxins, etc. and more particularly the greenhouse gas CO ₂ by prolonging its life cycle by its transformation into CO, which is a commonly used industrial gas.

According to the invention, the targeted reaction is more particularly the deoxidation, in this reactor 20, of water vapor H ₂ O dihydrogen H ₂ which is one of the two components of hydrocarbon molecules.

The reaction in this reactor 2 is carried out in two stages: 1. C + H ₂ O + CO + H ₂ 2. "CO Shift": CO + H ₂ O - »CO ₂ + H ₂

The first stage of this reaction is endothermic: 131 kJ / mol, the second stage is exothermic: 41 kJ / mol, the overall reaction is therefore endothermic and requires a thermal booster of 90 kJ / mol which is supplied to it by oxycombustion. at least a portion of the basic plant biomass in the reactor 10. An oxygen booster system is advantageously provided at the reactor 20 to overcome any energy deficiency.

According to the invention, therefore, we have two different gases leaving the reactors 10 and 20:

in reactor 1, we obtain CO by Boudouard's reaction, and

in reactor 2, we obtain CO ₂ and I ¹ H ₂ in a respective molar proportion and close to 1/3, 2/3. These gases are at very high temperature, greater than or equal to

1000 ⁰ C at the outlet of the reactor 10 and about 800 ⁰ C at the outlet of the reactor 20, they have a large heat capacity. These gases must be cooled to be purified and separated (in particular I ¹ H ₂ of CO ₂ ) they will therefore transit, each flow separately, by a water / gas heat exchanger. The water introduced to the exchanger is liquid, it allows to determine the adequate and constant temperature of the gas flow which will exchange its heat with this water. As the exchange progresses, the water is vaporized and the steam rises in temperature (600/800 ⁰ C) it is this "superheated" water vapor at high temperature which will be introduced into the hearth 20, as the second gaseous effluent, to be deoxidized in the reactor 20. In doing so, we recover and recycle a large part of the thermal energy used in the reactions.

The gases are thus cooled at the temperatures of use for their filtration / purification (transported aerosols, carbons, residual H ₂ O, etc.) and their separation, before being put into contact in a catalysis system dedicated to the defined formulation. of hydrocarbon compounds.

The CO ₂ produced by the combustion and the reactions of the source solid fuel is preferably, according to the invention, of vegetable origin (it is neutral with regard to the issue of greenhouse gases since the plant to renew absorbs its CO ₂ equivalent to regrowth). Its liquefaction (for industrial use), its sequestration, its transformation into CO (as a substitute for fossil fuels) makes it possible to reduce the proportion of industrial CO ₂ from fossil sources released to the atmosphere. Its recycling by the system according to the invention maximizes the conversion efficiency, the "source" energy of the initial solid fuel, energy made available by synthetic hydrocarbon compounds. The enclosure E is made to meet the temperature standards of the reactors 10 and 20. It can be considered that the gates 102 and 202 of each of the reactors 10 and 20 divide each of the reactors into two zones: an area upstream of the grid and an area downstream of the grid. Each of the reactors receives the inlet duct of the gaseous effluent to be treated in the upstream and outlet zone of the gaseous stream obtained in the downstream zone. The upstream zones also comprise the O 2 injectors. The upstream zone of the reactor 10 further comprises the inlet opening 103 of the biomass B. The zones of the reactors 10 and 20 downstream comprise the extraction openings, respectively 106 and 206, first and second gaseous streams 12 and 22 obtained and the discharge openings, respectively 107 and 207, of the residues R.

The enclosure according to the invention may be called the "Vegetable Carbon Reactor (RCV)".

The invention is of course not limited to the application example described above.

Claims

1) Process for treating a first gaseous effluent (11) essentially comprising carbon dioxide (CO ₂ ) and a second gaseous effluent (21) essentially comprising water vapor (H ₂ O), said process comprising the following steps:

- generating a first gas stream (12) comprising carbon monoxide (CO) by passing said first gaseous effluent (11) through a first layer of oxidation-reducing reactive material (101) comprising high temperature carbon elements ,

- Generating a second gas stream (22) essentially comprising dihydrogen (H ₂ ) by passing said second gaseous effluent (21) through a second reactive material redox layer (201) comprising high temperature carbon elements , and

- valorization of at least one of the first and second gas streams (12,22); at least a portion of said second oxidoreductive layer (201) being formed by transfer or recovery of at least a portion of the high temperature carbon elements of the first layer (101).

2) Process according to claim 1, characterized in that it comprises, during the passage of the second gaseous effluent (21) containing essentially water vapor (H ₂ O), through the second layer (201) containing high temperature carbon elements:

a reduction of the water vapor molecules (H ₂ O) in the presence of said carbon elements at high temperature, said reduction producing dihydrogen molecules (H ₂ ), and an oxidation of at least a part of said elements of high temperature carbon, said oxidation producing carbon dioxide (CO ₂ ) molecules; the second gas stream (22) essentially comprising dihydrogen (H ₂ ) and carbon monoxide (CO ₂ ). 3) Process according to any one of claims 1 or 2, characterized in that it comprises, during the passage of the first gaseous effluent (11) containing essentially carbon dioxide (CO ₂ ), through the first layer (101) containing high temperature carbon elements:

a reduction of the carbon dioxide (CO ₂ ) molecules in the presence of said carbon elements at high temperature, said reduction producing carbon monoxide (CO) molecules, and an oxidation of at least a portion of said carbon elements at high temperature, said oxidation producing carbon monoxide (CO) molecules.

4) Process according to any one of the preceding claims, characterized in that it comprises a heat exchange of at least one of the first and second gaseous stream (12,22) with a heat transfer stream, said gas stream yielding to least part of its thermal energy to said heat transfer stream.

5) Method according to claim 4, characterized in that the heat transfer stream comprises liquid water (H ₂ O _L ), the heat exchange producing a third gas stream (13, 23) comprising water vapor ( H ₂ O) at high temperature.

6) Process according to claim 5, characterized in that at least a portion of the water vapor (H ₂ O) contained in the second gaseous effluent (21) from the third gas stream (13, 23).

7) Process according to any one of claims 2 to 6, characterized in that it comprises a separation of the carbon dioxide (CO ₂ ) contained in the second gas stream (22), said separation providing a fourth stream (25) gas comprising essentially carbon dioxide (CO ₂ ) 8) Process according to claim 7, characterized in that at least a portion of the carbon dioxide (CO ₂ ) present in the first gaseous effluent (11) comes from the fourth gas stream (25).

9) Process according to any one of the preceding claims, characterized in that at least a part of the first oxidoreductive layer (101) is produced by combustion, in the presence of an oxidant (O ₂ ), a fuel comprising carbon elements under sub-stoichiometric conditions.

10) Process according to claim 9, characterized in that the solid fuel comprises plant biomass (B).

11) Process according to any one of claims 9 or 10, characterized in that the combustion is carried out oxygen oxidant (O ₂ ), said oxidant being injected into the heart of the first layer (101).

12) Process according to any one of the preceding claims, characterized in that the temperature of the first layer (101) is greater than or equal to 1000 ⁰ C.

13) Method according to any one of the preceding claims, characterized in that the temperature of the second layer (201) is between 700 to 1000 ⁰ C.

14) Process according to any one of the preceding claims, characterized in that it comprises a separation of the dihydrogen molecules (H ₂ ) present in the second gas stream (22), said separation providing a fifth gas stream (26) comprising essentially dihydrogen (H ₂ ).

15) Method according to any one of the preceding claims, characterized in that it comprises a synthesis of any composition molecular hydrocarbon from dihydrogen (H ₂ ) and carbon monoxide (CO).

16) Process according to any one of the preceding claims, characterized in that it further comprises a combustion of combustible particles present in the month one of the first and second gaseous effluent (11,21) during the passage of said gaseous effluent through the first layer and / or the second layer.

17) System for recycling a first gaseous effluent (11) essentially comprising carbon dioxide (CO ₂ ) and a second gaseous effluent (21) essentially comprising water vapor (H ₂ O), said system comprising an enclosure (E) comprising:

a first reactor (10) comprising a first gate (102) supporting a first reactive material redox layer (101) comprising high temperature carbon elements, said first layer (101) being traversed by said first gaseous effluent (11); providing a first gas stream (12) comprising carbon monoxide (CO), - a second reactor (20) comprising a second grid

(202) supporting a second reactive material redox layer (201) comprising high temperature carbon elements, said second layer (201) being traversed by said second gaseous effluent (21) providing a second gaseous stream (22) comprising dihydrogen (H ₂ ), and

- Extraction openings (106, 206) for separately extracting said first and second gas flows from said enclosure (E). said system further comprising means for upgrading at least one of said first and second gas streams (12,22).

18) System according to claim 17, characterized in that it comprises a communication opening (C) by which the first and second reactors (10,20) communicate with each other so that at least one part of the high temperature carbon elements of the first layer (101) passes from the first reactor (10) to the second reactor (20) through said communication opening (C) to form at least a portion of the second layer ( 201).

19) System according to claim 18, characterized in that the first gate (102) supporting the first layer (101) is at a location higher than the second gate (202) supporting the second layer (201), said first gate (102) being substantially inclined towards the second gate (202), the lower end of the first gate (102) being at the communication opening (C), so that at least a portion of the High temperature carbon elements of the first layer (101) flows from the first reactor (10) to the second reactor (20) to form the second layer (201).

20) System according to any one of claims 17 to 19, characterized in that the first and second grids (102, 202) are permeable to the first or second gas stream (12, 22), each of said grids (102,202) separating the reactor (10, 20) comprising said grid (102, 202) in a first and second zone, said first zone lying above said grid (102, 202) and including an opening (105, 205) for introducing gaseous effluent (11, 21) and said second zone lying below said gate (102, 202) and comprising an opening for extracting the gaseous flow (12, 22).

21) System according to any one of claims 17 to 20, characterized in that the first reactor (10) comprises an introduction opening (103), on the first gate (102), a fuel (B) comprising carbon elements, the first layer (101) being produced by combustion, in the presence of an oxidant (O ₂ ), said fuel (B) under substoichiometric conditions.

22) System according to any one of claims 17 to 21, characterized in that each of the first and second reactors (10, 20) comprises means (104, 204) for injecting an oxidant (O ₂ ) into said reactor (10, 20).

23) System according to any one of claims 17 to 22, characterized in that it comprises means for recovering residues (R) from each of the first and second reactors (10, 20), said residues (R) being discharged from each of said reactors (10, 20) through an exhaust opening (107, 207) located in the bottom of said reactor (10, 20).

24) System according to any one of claims 17 to 23, characterized in that it comprises at least one heat exchanger (E1, E2) performing a heat exchange of at least one of said first and second flow (12, 22) with a coolant (H ₂ O _L ).

25) System according to any one of claims 17 to 24, characterized in that the coolant is water (H ₂ O _L ), said heat exchanger (El, E2) providing a third gas stream (13, 23 ) comprising substantially high temperature water vapor (H ₂ O), said system further comprising a feed circuit of at least a portion of the third gas stream (13, 23) into the second reactor (20) .

26) System according to any one of claims 17 to 25, characterized in that it comprises separation means (24) of the different gaseous compound of the second gas stream (22), said second gaseous stream (22) comprising dihydrogen (H ₂ ) and carbon dioxide (CO ₂ ) obtained by oxidation-reduction of the water vapor (H ₂ O) in the presence of carbon elements at high temperature, said separation providing a fourth gas stream (25) comprising essentially carbon dioxide (CO ₂ ) and a fifth gas stream (26) essentially comprising dihydrogen (H ₂ ).

27) System according to claim 26, characterized in that it comprises a circuit for bringing at least a portion of the fourth stream (25) into the first reactor (10). 28) System according to any one of claims 17 to 27, characterized in that it comprises means for synthesis (30) of hydrocarbon molecules from dihydrogen (H ₂ ) and carbon monoxide (CO).