FR3072966A1 - SYSTEM FOR PRODUCING HIGH-CONVERSION SYNTHETIC HYDROCARBON WITH GAS VALUATION AND CONTROLLED AGING - Google Patents

Abstract

Synthetic hydrocarbon production system of formula CnH2n + 2 with n between 1 and 15, high conversion, greater than 90%, with valorization of at least one fluid and aging control, from the Fischer- Tropsch and / or Sabatier, comprising at least one source (2) of carbon dioxide and / or carbon monoxide and at least one source (3) of dihydrogen, said sources being capable of producing and injecting said fluids into a circulation circulation loop (1) adapted to the circulation and the recovery of a fluid with a controlled flow rate taking into account the nature of the catalyst, said fluids circulating in said circulation reaction loop (1) consisting of a mixture of dihydrogen, carbon monoxide and / or carbon dioxide, hydrocarbon and other gases, said circulation reaction loop (1) comprising: - circulation means and fluid recovery (10), - means s of flow control in the loop (1), - at least one reactor-exchanger (4) adapted for Fischer-Tropsch and / or Sabatier reactions, in particular for the catalytic hydrogenation reaction of carbon dioxide and / or carbon monoxide to synthetic methane, water vapor and other gases, - at least one condenser (5) for separating and discharging water vapor resulting from the catalytic hydrocarbon hydrogenation reaction and other gases, - at least one separator (8) for separating and discharging the hydrocarbon resulting from the condenser (5) from the other gases, - at least one compressor (9) for recovering and circulating the unseparated reactive fluid of the loop (1) with a suitable flow rate.

Description

SYSTEM FOR PRODUCING HIGH CONVERSION SYNTHESIS HYDROCARBON WITH GAS RECOVERY AND CONTROLLED AGING

The present invention relates to a system for the production of synthetic hydrocarbon of formula CnH2n + 2 with n between 1 and 15, with a conversion rate to synthetic hydrocarbon greater than 90% and with recovery of gases, from catalytic reactions. de Sabatier and / or Fischer-Tropsch.

It relates to a system for the production of synthetic hydrocarbon from an exchanger reactor using a fluid circulation loop with a regulated flow rate, making it possible to increase the residence time in the reactor-exchanger in order to obtain an output a highly concentrated synthetic hydrocarbon, preferably at a content greater than 90%, even when the catalyst activity is low and upgrading the untreated gases.

The invention particularly relates to a system for producing synthetic methane with a conversion rate greater than 90% obtained from the catalytic hydrogenation of carbon dioxide and / or carbon monoxide, said conversion rate being unchanged even when the aging of the catalyst is pronounced and is obtained by regulating the flow rate and by playing on various levers, namely: the temperature of the reaction, the pressure of the fluid, the quantity of the recovered gas.

More particularly, the present invention relates to a system for producing synthetic methane with a conversion rate greater than 90% into methane sized to operate over a wide operating range in terms of flow rate so as to withstand an increasing circulation flow rate. greater as the catalyst ages, so as to compensate for the drop in activity of said catalyst by a longer residence time.

Methanation is an industrial process for the catalytic conversion of dihydrogen and carbon monoxide and / or carbon dioxide to methane and water via the catalytic hydrogenation reaction. It can also be used to produce synthetic methane or other synthetic hydrocarbons from excess electricity production.

Fischer-Tropsch is a process involving the catalysis of carbon monoxide and hydrogen in order to convert them into hydrocarbons, in particular methane. The invention of the Fischer-Tropsch process dates back to 1923, the date which corresponds to the date of filing of the first patent attributed to two German researchers, Franz Fischer and Hans Tropsch.

The Sabatier reaction, discovered in 1912 by Sabatier, involves the reaction of dihydrogen and carbon dioxide at elevated temperatures and pressures in the presence of a catalyst to produce methane and water.

To date, the Fischer-Tropsch Sabatier reaction allows catalytic methanation to be carried out. This methanation is receiving a growing interest to date for its application to the electrical energy storage processes necessary for the development of renewable energies such as wind and / or solar. Its implementation requires the development of an innovative production system meeting the specifications of this application because the catalytic hydrogenation reaction of Sabatier or Fischer Fischer-Tropsch is an exothermic reaction which takes place at temperatures and pressures appreciably high in the presence of a catalyst.

The scenario which describes precisely the possible trajectory to reduce by a factor of four our greenhouse gas emissions and to get rid of our dependence on fossil and fissile energies by 2050 estimates that methanation could allow, in the near future , to use synthetic methane as a storage and transport vehicle for electricity of renewable origin, produced more and more massively. This electricity will be converted into hydrogen (by electrolysis of water) which, combined with carbon dioxide and / or carbon monoxide, would produce synthetic hydrocarbon, in particular synthetic methane, injectable into distribution networks and devices. existing storage. Such projects are developed by various gas operators.

It is also envisaged to use methanation to reduce the carbon dioxide emitted by cement factories, by combining it with hydrogen obtained by electrolysis from decarbonated electricity.

The technology used to date for methanation consists in introducing at the input of a catalytic reactor-exchanger, dihydrogen produced by the electrolysis of water and / or a hydrogen / carbon monoxide mixture (by gasification of organic matter (biomass, coal, etc.), and carbon dioxide and / or carbon monoxide and to collect water and methane at the outlet of said reactor-exchanger. Industrially, this process allows the production of synthetic methane with a methane conversion yield demonstrated to date on an industrial site of the order of 55%. This insufficient content of synthetic methane does not make it possible to cover the wide range of advantages that methanation offers as described above. There is therefore a great need to improve this yield. Indeed, obtaining this conversion of 55% into methane is already complex because of the catalyst which loses its activity (aging) as it is used making the system incapable of maintaining performance; those of obtaining a fluid rich in methane of required quality. In addition, heat recovery increases the overall energy efficiency by up to 85-89%. The heat thus recovered can be used to cover the needs of industry, the supply of district heating networks or even cogeneration of electricity. However, this yield remains insufficient.

One of the major problems encountered by systems for producing a hydrocarbon such as methane via catalytic methanation is that of obtaining a significant conversion into methane in order to obtain at the outlet a fluid rich in methane and compatible with the desired use, for example a network injection or a mobility application.

From publication US 2017 241338 is known a methane production system coupled to an energy production system by gas power plant comprising a catalytic reactor-exchanger for anaerobic digestion, one or more component (s) suitable for the cooling of the fluid, a heat exchanger to recover the heat, a compressor adapted to compress the gas. The methane produced by the reactor-exchanger is directly used to power the turbine. The combustible gas content is enriched through heat recovery. However, the system described is not a methanation system and the content of methane produced remains low. In this reactor, methane is produced by passing the combustible gas through a succession of methanization reactor-exchangers, including post-methanization, and therefore a high energy consumption, a strong degradation of the lifetime of the catalyst and a rate significant unprocessed gas.

One of the technical problems which arises for the production of a synthetic hydrocarbon, in particular methane, with the Fischer-Tropsch or Sabatier reactions is to reduce the rate of unprocessed gases, to value these gases in order to improve the conversion rate to methane.

Another technical problem which arises for the production of a synthetic hydrocarbon, in particular synthetic methane, with the Fischer-Tropsch or Sabatier reactions is the maintenance of the purity of the synthetic hydrocarbon, in particular methane from synthesis at the outlet of the reactor-exchanger at a content greater than 90% despite the aging of the catalyst. The dimensioning and the arrangement of the various technical means constituting the system for producing the hydrocarbon (methane) therefore appears necessary to operate the system over a wide operating range in terms of flow rate so as to withstand an increasingly fluid flow rate. more important as the catalyst ages.

The object of the invention is therefore to remedy these drawbacks by providing a system for producing synthetic hydrocarbon, in particular synthetic methane, highly concentrated with an increased hydrocarbon content of at least 90%, preferably 95%, from the Fischer-Tropsch and / or Sabatier reactions via a circulation and fluid recovery loop capable of upgrading the unconverted gases by circulating them in said loop, said loop comprising different technical means dimensioned and arranged to operate the system over a wide operating range in terms of flow rate so as to withstand an increasingly higher recycled flow rate as the catalyst ages.

In the following description, the following terms will have the following definition:

Regulation means: designate all the material and technical means making it possible to maintain each essential physical quantity equal to a desired value, called setpoint, by action on a regulating quantity, despite the influence of the disturbing quantities of the catalytic conversion like loss of catalyst activity.

Circulation: designates the circulation of the fluid with a view to its catalytic conversion.

Recovery: designates the circulation of part of the unconverted fluid resulting from the methanation reaction to hydrocarbon. The fluid not converted to hydrocarbon is injected into the reactor-exchanger in order to improve the conversion rate to hydrocarbon, in particular to methane.

Reaction loop: designates a loop comprising several elements capable of producing synthetic hydrocarbon, in particular synthetic methane, by the methanation reaction and in which the various reaction methanation mechanisms take place.

Reaction circulation loop: loop having simultaneously the functions of circulation, recovery and reaction loop.

The subject of the invention is a system for producing a synthetic hydrocarbon of formula CnH2n + 2 with n between 1 and 15, with high conversion, greater than 90%, with recovery of at least one fluid and with controlled aging, from Fischer-Tropsch and / or Sabatier reactions, comprising at least one source of carbon dioxide and / or carbon monoxide and at least one source of dihydrogen, said sources being capable of producing and injecting said fluids in a circulation reaction loop adapted to the circulation and recovery of fluids with a regulated flow taking into account the nature of the catalyst, the fluids circulating in said loop consisting of a mixture of dihydrogen, carbon monoxide and / or carbon dioxide, hydrocarbons and other gases, said circulation reaction loop comprising:

means for circulating and upgrading fluids, means for regulating flow capable of regulating the flow of fluid in the loop, at least one reactor-exchanger suitable for Fischer-Tropsch and / or Sabatier reactions, in particular for the catalytic hydrogenation reaction of carbon dioxide and / or carbon monoxide into synthetic methane, water vapor and other gases, said reactor-exchanger comprising at least one inlet for reactive fluid and at least one outlet for fluid, at least one condenser, connected to the reactor-exchanger via the circulation means (10), capable of separating and evacuating the water vapor resulting from the FischerTropsch and / or Sabatier reaction from the other gases, said condenser comprising at least less a fluid inlet resulting from the reactor-exchanger and two fluid outlets, one of which comprising at least one means for recovering the water vapor produced and the other intended for the circulation of non-fluid separated in a loop via the circulation means, at least one separator, connected to the condenser via the circulation-recirculation means, capable of separating and evacuating the hydrocarbon resulting from the condenser from the other gases, said separator comprising a reactive fluid inlet and two reactive fluid outlets, one comprising at least one means for recovering the hydrocarbon produced and the other ensuring the continuity of the loop by the circulation and recovery of the non-separated reactive fluid, at least one compressor, connected to the separator and to the reactor-exchanger via the circulation and recovery means, capable of recovering and circulating the reactive fluid not separated from the loop with a suitable flow rate so as to ensure the continuity of the catalytic hydrogenation reaction and compensate for the pressure losses resulting from the various pieces of equipment in the loop, said compressor comprising an inlet and an outlet for fluid.

According to other characteristics of the invention, the reaction circulation loop further comprises:

at least one mixer capable of mixing the reactive fluid circulating in said reaction circulation loop.

At least one heat exchanger capable of cooling, avoiding condensation and bringing the gases circulating in the loop to a predetermined operating temperature,

According to other characteristics of the invention, the reaction circulation loop further comprises:

at least one temperature sensor capable of controlling the management of the temperature of said exchanger and / or of the reactor-exchanger.

At least one flow sensor capable of independently controlling, regulating and managing the reactive fluid flows circulating in the loop and the fluid flow coming from the various sources and entering the loop in order to respect the desired stoichiometry at the inlet of the reactor -échangeur.

Advantageously, the source of carbon dioxide and / or carbon monoxide is directly connected upstream of the condenser and the source of dihydrogen is directly connected upstream of the reactor-exchanger.

Advantageously, the source of carbon dioxide and / or carbon monoxide and the source of dihydrogen are directly connected upstream of the reactor-exchanger or upstream of the condenser.

According to other characteristics of the invention:

the fluid circulating in the circulation and recovery means between the outlet of the reactor-exchanger and the inlet of the condenser is a mixture comprising at least one hydrocarbon, carbon dioxide and / or carbon monoxide, dihydrogen and vapors water and the fluid circulating in the circulation and recovery means between the outlet of the condenser and the inlet of the separator is a mixture comprising at least one hydrocarbon, carbon dioxide and / or carbon monoxide and dihydrogen , the fluid circulating in the circulation and recovery means between the outlet of the compressor and the inlet of the reactor-exchanger is a mixture comprising at least one hydrocarbon, carbon dioxide and / or carbon monoxide, dihydrogen and optionally water vapors and other gases.

Advantageously, the various means constituting the reaction loop are adapted, in terms of mechanical stress, to be able to operate with an adjustable fluid flow rate as a function of the conversion rate.

According to other characteristics of the invention, the reaction loop comprises at least one flow measurement means coupled to a calculation means, said means being capable of regulating the flow of the fluid flowing in said loop so as to maintain the purity d 'synthetic hydrocarbon, in particular synthetic methane, at an output higher than 90%.

According to other characteristics of the invention, the reaction loop comprises at least one means for measuring the catalytic conversion rate coupled to the calculation means, said means being capable of evaluating the aging of the catalyst and of regulating the flow rate of the circulating fluid. in said loop so as to maintain the purity of synthetic hydrocarbon, in particular synthetic methane, at the output at a content greater than 90%.

The synthetic hydrocarbon production system, in particular methane according to the invention has the advantage of being dimensioned to be able to operate over a wide operating range in terms of flow rate, which makes it possible to withstand a circulation flow rate and more and more recovery as the catalyst ages and to compensate for the drop in activity of the latter by a longer residence time of the reactive fluid in the loop. The variation in circulation flow and recovery of fluid makes it possible to maintain a methane conversion rate greater than 90% while compensating for the aging of the catalyst by circulation and by recovery, and therefore a longer residence time of the fluid in the loop.

Other characteristics and advantages of the invention will appear on reading the detailed description which follows and on studying the particular embodiments taken by way of nonlimiting example and illustrated by the appended drawings in which:

Figure 1 is a schematic representation of the synthetic hydrocarbon production system, in particular synthetic methane according to the invention;

FIG. 2 is an embodiment of the system for producing synthetic methane according to the invention;

FIG. 3 is another embodiment of the system for producing synthetic methane according to the invention;

FIG. 4 is a curve showing the loss of activity of the catalyst of the system for producing synthetic methane according to the invention, and the flow compensation necessary to compensate for it.

FIG. 1 shows a system for producing a synthetic hydrocarbon of formula CnH2n + 2 with n between 1 and 15, with high conversion, greater than 90%, with recovery of at least one fluid and with controlled aging, from Fischer-Tropsch and / or Sabatier reactions. It shows in particular a system for producing synthetic methane with a purity greater than 90%, preferably greater than 95% and with controlled aging, from the Fischer-Tropsch and / or Sabatier reactions. The system includes at least one source (2) of carbon dioxide and / or carbon monoxide and at least one source (3) of dihydrogen. Both sources are capable of producing and injecting fluids (carbon dioxide and / or carbon monoxide, dihydrogen and possibly other reactive gases promoting methanation), in a reaction circulation loop (1) of fluid.

The carbon dioxide and / or carbon monoxide of the source (2) results either from anaerobic digestion and / or from a pyrogasification and / or from other sources capable of producing these compatible reactive fluids for a methanation reaction by presence of a catalyst.

Dihydrogen results either from the electrolysis of water, or from hydrocarbons and / or other processes for producing this fluid known from the prior art.

Advantageously, the source (2) comprises carbon dioxide and / or carbon monoxide and / or hydrocarbon, in particular methane, preferably of low content resulting either from anaerobic digestion or from gasification and mainly comprises 40% of carbon dioxide.

Advantageously, the source (3) comprises dihydrogen and water, preferably dihydrogen and water vapor.

The two sources (2, 3) can be mixed together or else with a flow of hydrocarbon, preferably a flow of methane.

Reactive fluids from sources (1, 2) are injected into the circulation-recirculation reaction loop (1). This loop (1) has the particularity of carrying out the methanation reaction via the circulation of the fluid at a self-regulated flow rate, of recovering at least 90%, preferably at least 98%, of the water vapors resulting from the methanation and more than 90% of methane resulting from the methanation reaction, then circulating the unprocessed fluids for the recovered and again carrying out methanation.

The loop (1) comprises several elements dimensioned to supply at least 90% of hydrocarbon, preferably at least 90% of synthetic methane. It therefore meets very demanding specifications to obtain maximum energy efficiency in terms of catalytic methanation reaction.

With reference to FIG. 1, the fluids coming from the source (2) and from the source (3) are injected into the reaction circulation loop (1) in which the reactive fluid circulates with a self-regulating flow taking into account the nature of the catalyst and of the conversion rate into hydrocarbon, in particular into methane of synthesis of the methanation reaction; The injected fluid consists of a mixture of dihydrogen, carbon monoxide and / or carbon dioxide and other gases with a view in particular to a Sabatier and / or Fischer-Tropsch reaction. At the injection point of said fluids in the loop (1) is installed a non-return valve (11) which makes it possible to control the direction of circulation of the fluids entering the loop (1).

The loop (1) is dimensioned on the basis of a temperature loss and / or a temperature gain between the flow and the return of the fluid as one of the indices self-regulating the flow of fluid in the loop (1).

The circulation reaction loop (1) mainly comprises circulation and recovery means (10) of reactive fluid and unprocessed fluid, a reactor-exchanger (4), a condenser (5), a separator (8), a compressor (9), means for regulating flow, means for controlling the temperature, means for controlling the hydrocarbon content, means for controlling the activity of the catalyst, etc.

The circulation and recovery means (10) of the reactive and unprocessed fluid are dimensioned to circulate a flow of self-regulated fluid at pressures between 1 bar and 500 bars. These means (10) are grouped spatially to limit the length of the loop and maximize the rate of conversion to hydrocarbon, in particular to methane via Sabatier or Fischer-Tropsch methanation.

Advantageously, these means (10) include pipes, valves and flanges, check valves, shut-off valves, isolated conveying fluid on all the elements of the loop (1). These means (10) are isolated by means of a shell or a mattress. Preferably, the insulation thickness is at least 4 mm. The check valves prevent a reversal of the flow direction and the shut-off valve allows each circuit to be isolated from the loop so that work can be carried out there.

When a means (10) of the loop (1) supplies several branches or elements of the loop (1), each of these branches comprises at least one balancing member to guarantee good circulation and recovery of gases throughout the branch .

The flow regulation means are automatic means, that is to say without human intervention to maintain the flow at a set value. These regulation means capable of modifying or improving the reaction kinetics via by automatic adjustment of the fluid flow rate in the loop (1) on the basis of the temperature losses and / or temperature gains between the flow and the return fluid in the reactor-exchanger (4) and on the basis of the hydrocarbon content at the outlet of the reactor-exchanger (4).

Advantageously, the regulation means are of the PID (proportional, integrator, differentiator) type, that is to say at each instant the error is measured, which is the difference between the setpoint and the observed value, then the derivative of this error, and its integral over a certain time interval.

Advantageously, the regulation means include a flow regulation valve, a hydraulic distributor, a mass flow meter, with an analog or digital output, with a Multi-Gas / Multi-Range characteristic (25 gases selected), a configurable regulation characteristic. , many customizable input / output options.

The reactor-exchanger (4) is preferably a plate-reactor or shell-tube, or millistructured or honeycomb, etc. reactor-exchanger. suitable for the Sabatier and / or Fischer-Tropsch methanation reaction, in particular for the catalytic hydrogenation reaction of carbon dioxide and / or carbon monoxide to synthetic methane, water vapor and other gases. It comprises at least one inlet and at least one fluid outlet, and an inlet and an outlet for heat transfer fluid.

According to other characteristics of the invention, the reactor-exchanger (4) is a reactor of the adiabatic reactor type.

Advantageously, the reactor-exchanger (4) is a gas / solid catalytic reactor-exchanger, the solid phase for the catalyst and the gas phase for the reactants and the reaction products. The solid catalyst serves to increase the speed of the reaction and therefore, during its implementation, it is important to consider the catalyst assembly with its essential characteristics, namely its activity, its selectivity and its stability. It is also important to take into account the external and internal diffusional phenomena in the catalyst which could reduce the intrinsic qualities of the catalytic surface and therefore the conversion.

Advantageously, the reactor-exchanger (4) is a structured catalytic reactor-exchanger or a fixed-bed exchanger reactor. It comprises channels for the circulation of reactive fluid, which are filled with a catalyst in the form of powder and / or grains and channels for the circulation of heat transfer fluid.

The introduction of the reactive fluids resulting from the sources (2, 3) into the loop is done either just at the inlet of the reactor-exchanger, or just after the outlet of the latter. To make this choice, account must be taken of the composition of the fluids coming from the sources, the objective being to enter the reactor with a minimum hydrocarbon content, in particular methane and water vapor in order to be in the conditions most favorable to the methanation reaction. Thus a source of carbon dioxide and / or carbon monoxide containing water should preferably enter upstream of the condenser (5) as described in FIG. 2. On the contrary, the sources of carbon dioxide and / or carbon monoxide pure carbon and dihydrogen can be directly injected into the loop just upstream of the reactor (4).

The condenser (5) makes it possible to separate and evacuate the water vapor resulting from the Sabatier and / or Fischer-Tropsch reactions of hydrocarbon (methane) and other gases. The condenser (5) is connected to the reactor-exchanger (4) via the circulation and recovery means (10). It mainly comprises at least one fluid inlet resulting from the reactor-exchanger (4) and two fluid outlets, one of which comprises at least one means for recovering the water vapor produced (6) and the other intended for the circulation of the non-separated fluid in the loop (1) via the circulation and recovery means (10) (circulation of the non-separated fluid with a view to injecting it into the separator (8) for the production of hydrocarbon with increased purity) .

According to the invention, the condenser (5) is dimensioned to liquefy water vapor.

The separator (8) is connected to the condenser (5) via the circulation and recovery means (10). It makes it possible to separate and evacuate the hydrocarbon, in particular methane from the other gases resulting from the condenser (5). This separator (8) comprises a fluid inlet resulting from the condenser (5) and two fluid outlets, one of which comprises at least one means of recovery (7) of pure hydrocarbon produced by the Sabatier and / or Fischer reactions -Tropsch and the other ensuring the recovery of unprocessed fluids via the circulation and recovery means (10) of the non-separated fluid, thus ensuring the continuity of the loop (1). The non-separated fluid is injected into the compressor (9) then into the reactor-exchanger (4).

Advantageously, the separator (8) is a reactor-exchanger or a purifier of the membrane separation type or separation by adsorption or by pressure inversion.

The compressor (9) is connected to the separator (8) and to the reactor-exchanger (4) via the circulation and recovery means (10). It makes it possible to enhance and circulate the non-separated fluid in the loop (1) with an adapted flow rate so as to ensure the continuity of the catalytic hydrogenation reaction and to compensate for the pressure losses resulting from the various devices of the loop ( 1). This compressor (9) comprises a fluid inlet and outlet and automatic means for regulating the pressure and / or the flow rate.

The hydrocarbon production system of formula CnH2n + 2 with n between 1 and 15 according to the invention operates as follows:

Step 1: sources (2, 3) are introduced into an exchange reactor (4), a reactive fluid comprising a mixture of carbon dioxide and / or carbon monoxide and dihydrogen. Via the circulation and recovery means (10), this reactive fluid is brought to the inlet of the reactor-exchanger (4) at a working pressure corresponding to the operating pressure of the reactor-exchanger (4), thereby circulation of this reactive fluid in the reactor-exchanger (4) triggers, in the presence of the catalyst, the catalytic methanation reaction of Sabatier and / or Fischer-Tropsch via the catalytic hydrogenation of carbon dioxide or carbon monoxide to hydrocarbon synthesis, including synthetic methane, water vapor and other gases.

Step 2: the gases leaving the reactor-exchanger (4) resulting from the Sabatier catalytic methanation reaction are injected into the condenser (5) via the means (10) to separate, liquefy and recover the water vapor resulting from this methanation reaction, in particular the Sabatier and / or Fischer-Tropsch reactions. The resulting liquefied water is collected in the means (6) suitable for this purpose. The other gases resulting from the methanation reaction, including the hydrocarbon, in particular methane, and the vapors of non-liquefied water, are injected, via the means (10) into the separator (8).

Step 3: the separator (8) separates for this purpose the hydrocarbon (methane) resulting from the methanation reaction of the other gases. Depending on the quality of this separator (8), part of the hydrocarbon may not be separated and remains with the other gases. The separated hydrocarbon (methane) is collected in the means (7) dedicated for this purpose. The non-separated gases are injected via the means (10) into the compressor (9). The separation provides a high quality methane flow.

Step 4: The self-regulating compressor (9) regulates the flow and pressure of the gases resulting from the separator (8) to bring them to a nominal pressure and flow corresponding to the operation of the exchanger reactor (4), of course taking into account the nature of the catalyst via a measurement of the conversion rate of the Sabatier and / or Fischer-Tropsch reactions, of the temperature of the loop and allow the circulation (recovery) of the gases to compensate for the losses of charges generated by the various equipment of the loop, in particular by the separation means (8) often generating high pressure drops. These gases resulting from the compressor, at a pressure and a self-regulated flow rate, are injected again into the reactor-exchanger to continue the methanation reaction in order to obtain synthetic methane with an increased content greater than 90%.

Step 5: the process is repeated until the complete conversion and / or exhaustion of the reactive fluids and obtaining a conversion rate greater than 90% into methane, thus the reaction circulation loop is defined (1). The recovered fluid is mixed with the fluid injected into the loop by the sources (1, 2).

It should be noted that most of the methanation systems known in the state of the art compensate for the aging of the catalyst by increasing the temperature and / or the operating pressure. If this method works with a conversion rate of less than 90%, it has the disadvantage of making the operating conditions unfavorable for the catalyst, which accelerates its aging (the loss of activity of the catalyst). The invention has the particularity of using circulation-recovery to enable efficient conversion to be maintained via the catalytic methanation reaction of Sabatier and / or Fischer-Tropsch without increasing the severity of the operating conditions (temperature and pressure) and of limiting aging as much as possible in order to reduce the frequency of maintenance operations.

With reference to FIG. 2, the gases resulting from the sources (2, 3) are injected into the circulation-recirculation loop (1) upstream of the condenser (5). This embodiment is suitable for a source rich in dihydrogen comprising a large part of water.

With reference to FIG. 3, the gases resulting from the sources (2) are injected into the loop (1) upstream of the reactor-exchanger and the gases resulting from the sources (3) are injected into the loop of (1) upstream of the condenser (5). This embodiment is suitable for a source rich in hydrocarbons, in particular methane.

Advantageously, the system comprises several exchanger reactors mounted in series or in parallel to improve the conversion rate of carbon dioxide and of dihydrogen and to obtain at the output a conversion rate into hydrocarbon, in particular into methane, greater than 90% preferably greater than 98 %.

In the case where the system comprises several exchanger reactors (4) in series, only the first exchanger reactor (4) is capable of carrying out quantitative methanation, the other exchanger reactors (4) being adapted to carry out qualitative methanation by purification of the hydrocarbon (methane) at the outlet and the recovery of other gases via circulation and recovery in the loop (1). The other reactor-exchangers (4) are in this case used as being purifiers.

In the case where the system comprises several reactor-exchangers in parallel, all the exchanger reactors are adapted to carry out a quantitative conversion via the Sabatier and / or Fischer-Tropsch reactions to increase production, that is to say , more inlet gas and more outlet gas.

FIG. 4 shows a curve for the conversion of carbon dioxide in the reactor-exchanger as a function of the self-regulation of the flow rate at the inlet of the reactor-exchanger, showing the control of the aging of the catalyst. When the activity of the catalyst decreases, in particular the lifetime of the catalyst decreases, the conversion rate of carbon dioxide drops and the gas flow rate increases in order to maintain an almost constant production of hydrocarbon at the output with an increased content greater than 90%. Thus, even with an aging catalyst, it is possible to produce hydrocarbon (methane) at an increased content via an increase in recovery (circulation of the fluid for recovery).

Advantageously, the circulation reaction loop (1) further comprises a mixer, a heat exchanger, a temperature sensor and a flow sensor. Advantageously, the loop 1 comprises at least two mixers, preferably a mixer upstream of the reactor-exchanger (4) and / or a mixer upstream of the condenser (5), making it possible to mix the reactive fluid circulating and recovered in said loop ( 1).

Advantageously, the loop (1) comprises at least one heat exchanger upstream and / or downstream of the reactor-exchanger, upstream and / or downstream of the separator to cool and / or avoid condensation and finally carry the gases circulating in the loop (1) at a predetermined operating temperature for the methanation reaction.

Several temperature sensors are placed in the loop (1), in particular at the level of the reactor-exchanger (4) or other exchangers to control the management of the temperature of said exchangers and / or of the reactor-exchanger (4). Preferably, these sensors are thermocouples or resistance probes.

Also, several flow sensors are placed in the loop (1), in particular at the level of the valves, in particular at the input and output of the various equipment constituting the loop (1), to control, regulate and manage autonomously the flow rates of reactive fluid. circulating in the loop (1) and the fluid flow rate coming from the different sources and entering the loop (1) and in order to respect the desired stoichiometry at the inlet of the reactor-exchanger (4).

According to other alternative embodiments, the source (2) of carbon dioxide and / or carbon monoxide is connected upstream of the condenser (5) and the source (3) of dihydrogen is directly connected to the inlet of the reactor. -exchanger (4). This principle is suitable for the system with a rich source of methane, for example a methanation unit, with the aim of recovering said methane via the methanation reaction.

According to other alternative embodiments, the source (2) of carbon dioxide and / or carbon monoxide and the source (3) of dihydrogen are connected upstream of the reactor-exchanger (4) or to the condenser inlet. This principle is suitable for the system with a poor methane source, for example a carbon dioxide or carbon monoxide capture unit, with the objective of recycling said gases by producing methane via catalytic methanation.

Advantageously, the fluid circulating in the means (10) between the outlet of the reactor-exchanger (4) and the inlet of the condenser (5) is a mixture comprising methane, carbon dioxide and / or carbon monoxide, hydrogen and water vapors.

The fluid flowing in the means (10) between the outlet of the condenser (4) and the inlet of the separator (8) is a mixture comprising methane, carbon dioxide and / or carbon monoxide and dihydrogen.

The fluid circulating in the means (10) between the outlet of the compressor (9) and the inlet of the heat exchanger reactor (4) is a mixture comprising methane, carbon dioxide and / or carbon monoxide, dihydrogen and possibly water vapors and other gases. These to better recover unpurified gases and improve the purification of methane leaving the separator.

The different means constituting the loop (1) are adapted, in terms of mechanical stress, to be able to operate with an adjustable fluid flow rate as a function of the conversion rate.

For good flow control, the loop (1) comprises at least one flow measurement means coupled to a calculation means, said means being capable of regulating the flow rate of the fluid circulating in said loop (1) so as to maintain the purity of synthetic hydrocarbon at output at a content greater than 90%. This calculation means can be coupled to a servo and control system.

According to other characteristics of the invention, the reaction loop (1) comprises at least one means for measuring the catalytic conversion rate coupled to the calculation means, said means being capable of evaluating the aging of the catalyst and of regulating the flow rate of the fluid circulating in said loop so as to maintain the purity of synthetic hydrocarbon at the outlet at a content greater than 90%.

It should be noted that the introduction of the reactive gases is made either just before the reactor-exchanger, or after the reactor-exchanger, so as to make the best use of the exchange surface. In some cases, it is possible to introduce fresh reagents upstream of the pump (depending on the pressure of the sources), so as to take advantage of the lower pressure at this point to suck them up and thus to achieve a rapid mixing of the reagents fresh with the reaction medium.

The design of such a methanation system takes account of the residence time of the reactants in the loop (1), the total volume of reaction medium being determined, that of the recovery means (6, 7) is deducted from the volumes corresponding to the buckle (1). The circulation flow is between 1 and 20 times the supply flow. Thus, when the catalyst has a low activity and for a circulation rate equal to 20 times, the methane content produced remains almost unchanged. The ratio between the circulation flow rate and the gas injection flow rate in the loop (1) should be all the more the greater the conversion.

Another element to take into account to self-regulate the circulation rate relates to the heat exchange. Indeed, the temperature difference between the inlet and the outlet of the reactor-exchanger will be lower the higher the circulation rate (recovery).

The different means constituting the reaction loop (1) are adapted, in terms of mechanical and thermal stress, to be able to operate with an adjustable fluid flow rate as a function of the conversion rate. The dimensions of each section of the loop (1) are chosen so as to respect these constraints, they are determined according to the need for fluid. Once the design of the loop (1) has been completed, the first step in the design of a circulation and recovery loop (1) in order to circulate and enhance the fluids consists in evaluating the rate at which this loop (1) will lose heat.

It can therefore be seen that it is possible to industrially produce a system for the production of synthetic hydrocarbon of formula CnH2n + 2 with n between 1 and 15, with a conversion rate to synthetic hydrocarbon greater than 90%, at starting from the catalytic reactions of Sabatier and / or Fischer-Tropsch, directly usable even with a pronounced aging of the catalyst and by developing reactive gases in a reasonable manner, that is to say without loss of reactive gas.

Contrary to the prejudices which consisted in believing that it is difficult to produce synthetic hydrocarbon, in particular synthetic methane, at a content greater than 90% without loss of reagent with the Sabatier and / or Fischer-Tropsch reactions, it is now possible to size and manufacture a methanation system demonstrating the Sabatier and / or Fischer-Tropsch reactions, capable of producing hydrocarbon, in particular methane at a content greater than 90% without loss and even with a low activity of the catalyst while recycling reactive gases. It is therefore possible to circulate and recover the gases via the self-regulating circulation and recovery loop (1) to produce a highly concentrated synthetic hydrocarbon.

The methanation system according to the invention is in no way limited to the embodiments described and shown, but a person skilled in the art will know how to make any variant which conforms to his spirit, particularly in other technical fields of catalytic conversion.

Claims (9)

1) Synthetic hydrocarbon production system of formula CnH2n + 2 with n between 1 and 15, with high conversion, greater than 90%, with recovery of at least one fluid and with controlled aging, from the reactions of Fischer-Tropsch and / or Sabatier, comprising at least one source (2) of carbon dioxide and / or carbon monoxide and at least one source (3) of dihydrogen, said sources being capable of producing and injecting said fluids in a reaction circulation loop (1) suitable for the circulation and recovery of a fluid with a regulated flow taking into account the nature of the catalyst, said fluids circulating in said reaction circulation loop (1) consisting of a mixture of dihydrogen, carbon monoxide and / or carbon dioxide, hydrocarbon and other gases, said circulation reaction loop (1) comprising: means for circulating and upgrading fluid (10), means for regulating flow capable of regulating the flow of fluid in the loop (1), at least one reactor-exchanger (4) suitable for the Sabatier and / or FischerTropsch reactions , in particular for the catalytic hydrogenation reaction of carbon dioxide and / or carbon monoxide into synthetic methane, water vapor and other gases, said reactor-exchanger comprising at least one inlet for reactive fluid and at least one fluid outlet, at least one condenser (5), connected to the reactor-exchanger via the circulation means (10), capable of separating and evacuating the water vapor resulting from the Sabatier and / or Fischer-Tropsch reactions from the others gas, said condenser (5) comprising at least one fluid inlet resulting from the reactor-exchanger (4) and two fluid outlets, one of which comprising at least one means for recovering the water vapor produced (6) and the other intended for the circulation of fluid not separated in the loop via the circulation means (10), at least one separator (8), connected to the condenser (5) via the circulation recirculation means (10), capable of separating and evacuating the methane resulting from the condenser ( 5) of other gases, said separator (8) comprising a reactive fluid inlet and two reactive fluid outlets, one of which comprises at least one means for recovering hydrocarbon, in particular methane, product (7) and the other ensuring the continuity of the loop (1) by circulation and recovery of the non-separated reactive fluid, at least one compressor (9), connected to the separator (8) and to the reactor-exchanger (4) via the circulation and recovery (10), capable of recovering and circulating the reactive fluid not separated from the loop (1) with a suitable flow rate so as to ensure the continuity of the catalytic hydrogenation reaction and compensate for the pressure losses resulting from the different teams elements of the loop (1), said compressor (9) comprising an inlet and an outlet for fluid. 2) Production system according to claim 1 characterized in that the reaction circulation loop (1) further comprises: at least one mixer capable of mixing the reactive fluid circulating in said reaction circulation loop (1). At least one heat exchanger capable of cooling, preventing condensation and bringing the gases circulating in the loop (1) to a predetermined operating temperature, 3) Production system according to claim 1 or 2 characterized in that the reaction circulation loop (1) further comprises: at least one temperature sensor capable of controlling the management of the temperature of said exchanger and / or of the reactor-exchanger (4). At least one flow sensor capable of controlling, regulating and managing autonomously the flow rates of reactive fluid circulating in the loop (1) and the flow of fluid coming from the different sources and entering the loop (1) in order to respect the desired stoichiometry at the inlet of the reactor-exchanger (4). 4) Production system according to any one of the preceding claims, characterized in that the source (2) of carbon dioxide and / or carbon monoxide is directly connected upstream of the condenser (5) and the source (3) of dihydrogen is directly connected upstream of the reactor-exchanger (4). 5) Production system according to any one of the preceding claims, characterized in that the source (2) of carbon dioxide and / or carbon monoxide and the source (3) of dihydrogen are directly connected upstream of the reactor-exchanger (4) or upstream of the condenser. 6) Production system according to any one of the preceding claims, characterized in that: the fluid circulating in the circulation and recovery means (10) between the outlet of the reactor-exchanger (4) and the inlet of the condenser (5) is a mixture comprising at least one hydrocarbon, carbon dioxide and / or carbon monoxide, dihydrogen and water vapors and, the fluid circulating in the circulation and recovery means (10) between the outlet of the condenser (4) and the inlet of the separator (8) is a mixture comprising at minus a hydrocarbon, carbon dioxide and / or carbon monoxide and dihydrogen, the fluid circulating in the circulation and recovery means (10) between the outlet of the compressor (9) and the inlet of the reactor-exchanger ( 4) is a mixture comprising at least one hydrocarbon, carbon dioxide and / or carbon monoxide, dihydrogen and optionally water vapors and other gases. 7) Production system according to any one of the preceding claims, characterized in that the different means constituting the reaction loop (1) are adapted, in terms of mechanical stress, to be able to operate with an adjustable fluid flow rate as a function of the rate of conversion. 8) Production system according to any one of the preceding claims, characterized in that the reaction loop (1) comprises at least one flow measurement means coupled to a calculation means, said means being capable of regulating the flow of the circulating fluid in said loop (1) so as to maintain the purity of synthetic hydrocarbon at the output at a content greater than 90%. 9) Production system according to claim 8 characterized in that the reaction loop (1) comprises at least one means for measuring the catalytic conversion rate coupled to the calculation means, said means being capable of evaluating the aging of the catalyst and of regulate the flow rate of the fluid circulating in said loop so as to maintain the purity of synthetic hydrocarbon at an output at a content greater than 90%. F i G A FRENCH REPUBLIC irai - I NATIONAL INSTITUTE PROPERTY INDUSTRIAL PRELIMINARY SEARCH REPORT based on the latest claims filed before the start of the search National registration number FA 847275 FR 1701115 EPO FORM 1503 12.99 (P04C14) DOCUMENTS CONSIDERED AS RELEVANT Relevant claim (s) Classification attributed to the invention by ΙΊΝΡΙ Category Citation of the document with indication, if necessary, of the relevant parts X AT De Saint Jean: Power-to-gas process with high temperature electrolysis and C02 methanation, November 30, 2013 (2013-11-30), XP055475558, Extract from the Internet: URL: https: //ha1-cea.archi ves-ouvertes.fr/c ea-00958864 / document [extract 2018-05-16] * page 13 * * pages 7, 10-16 * US 2010/175320 Al (SCHUETZLE DENNIS [US] ET AL) July 15, 2010 (2010-07-15) * figures 1-2 * * paragraphs [0073] - [0075] * 1-9 1-9 C10G2 / 00 C07C9 / 04 TECHNICAL AREAS SOUGHT (IPC) C10G C07C Research Completion Date Examiner May 16, 2018 Bernet, Olivier CATEGORY OF DOCUMENTS CITED T: theory or principle underlying the invention E: patent document with an earlier date X: particularly relevant on its own at the filing date and which was not published until that date Y: particularly relevant in combination with a deposit or at a later date. other document of the same category D; cited in request A: technological background L: cited for other reasons O: unwritten disclosure P: interlayer document &: member of the same family, corresponding document ANNEX TO THE PRELIMINARY RESEARCH REPORT RELATING TO THE FRENCH PATENT APPLICATION NO. FR 1701115 FA 847275 This appendix indicates the members of the patent family relating to the patent documents cited in the preliminary search report referred to above. The said members are contained in the computer file of the European Patent Office on the date dulo-05-2ülo The information provided is given for information only and does not engage the responsibility of the European Patent Office or the French Administration