IT202000022336A1 - PROCESS OF CONVERSION OF FUEL INTO SEPARATE STREAMS OF CARBON DIOXIDE AND HYDROGEN - Google Patents

Description

Patent application for industrial invention entitled:

?PROCESS OF CONVERSION OF FUEL INTO CURRENT

SEPARATE OF CARBON DIOXIDE AND HYDROGEN?

DESCRIPTION

The present invention relates to a process for converting fuel into separate streams of carbon dioxide (CO2) and hydrogen (H2).

In particular, the present invention refers to a process suitable for decarbonisation, especially in industrial sectors which make extensive use of energy and fossil fuels.

Furthermore, the present invention can also be used in sectors specialized in the production of fuels or in the production of consumer products typical of the chemical industry, such as ammonia for example. Climate change and the growing attention on sustainability issues? are leading to a great sensitivity? on issues relating to pollution, also at a regulatory level.

As an example, the commitment made in the United Nations Framework Convention on Climate Change (UNFCCC) to reduce greenhouse gas (GHG) emissions, mostly from greenhouse gases, is cited. derived from the combustion of fossil fuels.

Despite this, CO2 emissions continue to increase, making it even more? important is the development of low carbon footprint technologies (carbon footprint), especially in productive sectors so? strategic, such as those of energy and fuel production, but also in the petrochemical sector and in the production of iron, steel and cement, as well as as in transport.

In this regard, the technologies aimed at the capture and sequestration of carbon (C) and/or carbon dioxide (CO2), called carbon capture & storage (CSS), are increasingly important to contain the increase in average temperature and to capture, and store, a quantity? of carbon dioxide CO2 equal to at least 100 gigatonnes in the next 30 years, as required by current international agreements.

A first solution to the problem? the use of renewable energy sources.

However, the known solutions which provide for the use of electricity? produced from renewable sources are still experiencing difficulties today? in real applications and above all with results that can be considered competitive, in the sectors mentioned above.

The electricity produced from renewable sources?, for example, suitable for powering small vehicles, such as city cars and small ferries, while ? it is still difficult to guarantee the autonomy of vehicles or larger industrial plants.

Furthermore, these solutions can further aggravate the current pollution situation especially if they are used as they are in today's context, i.e. in the current situation in which the production of electricity and fuel is ? still high intensity? of carbon dioxide production. In the context of climate change mitigation, the capture of carbon dioxide CO2, on the other hand, has the advantage of being able to be applied to different sectors, increasing the spectrum of possible applications and thus being able to contribute significantly to the reduction of pollution and the greenhouse effect in sectors with high energy and/or fuel consumption.

The capture of? Carbon dioxide pu? take place in various ways: by post-combustion capture, by oxy-combustion or by pre-combustion capture.

The separation of CO2 from combustion products? referred to as post-combustion capture, i.e. combustion occurs first and only then is carbon dioxide captured.

Post-combustion has the advantage of being able to rely on more consolidated technologies and of being able to be applied to conventional processes since by its nature it acts on the fumes coming out of the plants.

On the other hand, however, post-combustion has the disadvantage of presenting more specific energy consumptions. high because? intervenes with low thrust processes, having to treat fumes at low pressures, in which the CO2 ? diluted.

Oxy-combustion refers to the re-engineering of the combustion process to produce pure CO2 through the condensation of water vapor from the combustion fumes.

Oxy-combustion has the disadvantage of being a process that is not yet mature from a technological point of view, as well as being expensive and energy-intensive. energy, especially in relation to the separation of oxygen from the air.

By pre-combustion, on the other hand, we mean the decarbonisation of the fuel, i.e. the capture of CO2, before its combustion.

The pre-combustion processes offer a better thermodynamic efficiency in terms of carbon dioxide separation, and therefore of energy produced in the case of application to a power plant.

However, these solutions also have drawbacks.

In fact, current pre-combustion processes are generally represented by complex processes with numerous units, which are difficult to adapt to plants built with conventional schemes.

Furthermore, the solutions known to date cannot be adapted or modified to be suitable for different plant requirements.

And again, given the complexity? both structural and process of the known systems of pre-combustion these are little used, since? still have high specific costs (understood as cost per ton of CO2 captured).

Furthermore, these known solutions, in addition to invalidating the flexibility? of the pre-combustion process, have a high number of heat exchange surfaces which prevent optimization of the process itself and also prevent obtaining control of the process temperature.

The effect of these drawbacks is, for example, the presence of hot spots, which can compromise the activity? of the reaction catalyst, or of "counter zones", i.e. zones with less efficiency, where the temperature does not reach the optimal levels.

? It is therefore an object of the present invention to provide a process for converting fuel into separate streams of carbon dioxide CO2 and hydrogen H2. ? moreover, the purpose of the present invention is to reduce the carbon footprint of companies involved in high-intensity sectors? of production of carbon dioxide CO2.

Another purpose of the present invention ? realizing a pre-combustion process such as to overcome the drawbacks of the prior art, and be easily adaptable to different situations of use.

Another object of the present invention ? that of creating a versatile process, i.e. easily modifiable and adaptable to conventional processes.

Still another purpose? is to provide an easily scalable process, i.e. replicable even in different sizes, while maintaining the characteristics of versatility? and flexibility.

Still another purpose? that of creating a process that is easy and economical to implement, even in off-shore contexts.

According to the invention, these objects and others still are achieved by a process for converting fuel into separate streams of carbon dioxide CO2 and hydrogen H2 having the technical characteristics described in the attached claims.

The technical characteristics of the invention, according to the above purposes, are clearly described in the attached claims and its advantages are evident from the detailed description that follows, with reference to the attached drawings which illustrate embodiments thereof which are purely exemplary and non-limiting, in which :

Figure 1 schematically illustrates the process of converting fuel into separate streams of carbon dioxide CO2 and hydrogen H2 according to the present invention in a first embodiment; Figure 2 schematically illustrates the process of converting fuel into separate streams of carbon dioxide CO2 and hydrogen H2 according to the present invention in a second embodiment;

Figure 3 schematically illustrates the process of converting fuel into separate streams of carbon dioxide CO2 and hydrogen H2 according to the present invention in a third embodiment; Figure 4 schematically illustrates a part of the process of converting fuel into separate streams of carbon dioxide CO2 and hydrogen H2 according to the present invention in a fourth embodiment;

- figures 5, 6 and 7 show, schematically, three further embodiments of part of the process shown in figure 4.

In the following, by substance he means a homogeneous system of definite and constant composition, characterized by properties specific physicochemical.

Nouns can be elementary or compound.

By elementary substance or simple substance we mean a substance made up of equal atoms, i.e. of the same chemical element (for example O2, N2, H2).

By compound substance, or chemical compound, we mean a substance made up of atoms of different nature (for example H2O, CO2, CO).

By mixture we mean a set of pi? substances in varying proportions.

A component is a chemical species or substance that is part of a mixture.

A reactant is a component that takes part in a chemical reaction.

Reaction products are components, substances, residues or traces obtained by reacting components, substances, residues or traces in a chemical reaction. The inert materials are also included among the products of the reaction.

To a chemical process, or process step, ? associated with one or more chemical reactions.

By chemical reaction we mean the equation that synthesizes a phase, or part of a phase, of a chemical process.

By reaction environment we mean the physical place where the reaction takes place.

For example, in the case of a reforming reaction with steam? Is the reaction environment? represented by a reactor.

Yet another example, in the case of a water displacement reaction, does the reaction environment ? represented by a reactor.

For isolation of a substance/compound we mean the capacity? to produce this substance/compound among the products of a chemical reaction, so that they can be subjected to subsequent extraction treatments.

By extraction, from which the action of extracting, of a component is meant the subtraction of the component from a reaction environment, whether it is a reactant of the reaction or a product of the same, including the development or subtraction of heat.

The extraction can? be of a chemical, physical or mechanical nature, so that? the component can be physically separated from the rest of the reaction components.

By separation, or capture or seizure, from which the action of separating, capturing or seizing, we mean the combination of the two processes of isolation and extraction as defined above.

By conversion of fuels we mean the series of chemical and/or physical reactions to which ? subjected a fuel, part of it or a mixture of fuels in order to modify its chemical composition or properties? chemical and/or physical. The separation of at least one of the components, reactants or products, of at least one chemical reaction to which ? subjected to a fuel or a part of it is considered included in the conversion processes.

By product stream we mean a flow or flow rate, for example mass or molar, of a product. By steam reforming, also known as reforming or steam reforming reaction, we mean a reaction aimed at the production of a gas mixture starting, for example, from coal, hydrocarbons or biomass, and water steam, the primary goal? the production of hydrogen H2.

It differs from general catalytic reforming which does not involve steam.

By water displacement, also called water gas shift reaction or wgs reaction (from the English water-gas shift reaction) or Dussan reaction, we mean the chemical reaction between carbon monoxide CO and water H2O whose objective primary ? the production of hydrogen H2 and carbon dioxide CO2, according to the reaction:

CO H2O ? CO2 + H2

Both the steam reforming reaction and the water displacement reaction occur within a reactor and require catalysts, not shown, in order to occur.

For the purposes of the present invention, the symbol H2O means both water vapor, i.e. as a gaseous compound, and water, understood as a liquid compound.

The indication H2O water must therefore mean water in a liquid or gaseous state, unless expressly indicated otherwise.

Sar? to be deduced from the context, i.e. from the temperature and pressure, the prevailing state of the compound, whether liquid or gaseous.

To modulate is meant the action of controlling or determining in a variable way the quantity? required of a particular component to be supplied/extracted to/from a reaction, depending on the process conditions and the conditions of the reaction so that? such a reaction may occur or be favored.

By flame temperature we mean the theoretical combustion temperature calculated, using the first law of thermodynamics, as the temperature of the reaction products leaving an adiabatic chamber. With reference to the attached figures, with the number 1 ? indicated as a whole a process of converting fuel RR1 into separate streams of carbon dioxide CO2 and hydrogen H2 carried out in accordance with the present invention.

In particular, process 1 comprises the steps described below.

Phase 9, phase 10 and phase 11 respectively indicate the preparation of water H2O, a fuel RR1 and a component RR2.

Advantageously in phase 9 the water prepared ? in the liquid state.

Can? be, for example, sea, lake, river or other source water.

In embodiments not shown, the step 9 of preparing water comprises the step of pre-treating the water before being prepared in process 1.

The step of pretreating the water, in embodiments not shown, comprises the step of demineralizing the water.

In these solutions the water? advantageously sent to a boiler.

Pi? in detail, the fuel RR1 ? a fuel selected from the group including methane, natural gas, liquid natural gas (LNG), biogas, coal, biomass, methane-containing blend, methanol, propane, diesel, aircraft fuel, kerosene, ammonia, fossil fuel, or a combination thereof.

In embodiments, not shown, which prepare the fuel RR1 in solid or liquid form, such as for example biomass, the process 1 provides for a further pre-treatment step of the fuel RR1.

Thereby ? possible to start the process according to the present invention correctly.

The pre-treatment phase allows to eliminate at least part of the fuel RR1 in solid state or to eliminate residues not functional to process 1.

The pretreatment step, in embodiments not shown, comprises the gasification step.

The gasification phase allows to bring at least part of the fuel RR1 into a gaseous state before starting process 1.

For example, for the treatment of biomass and coal, the pre-treatment phase allows components such as char, tar and sulfur to be removed.

Following the pre-treatment phase, the fuel RR1 ? able to develop carbon monoxide CO when ? reformed with steam.

The RR2 component? a component selected from the group comprising oxygen, air, steam, water, or a combination thereof.

Pi? in particular, according to the reaction, the component RR2 ? an oxidiser or an inert, or rather participates in a more? or less active to the chemical reaction.

For example, the water vapor for combustion (first reaction r1) acts as an inert, ie it does not participate in the chemical reaction, even though it modifies the reaction environment.

Oxygen and air, for example, have the role of comburents for the combustion of methane CH4 (first reaction r1), i.e. they react chemically with each other.

Sar? to deduce from the context of the reaction, the role of the component RR2, i.e. whether it is an oxidizer or an inert agent.

After phases 9, 10 and 11, we move on to phase 12, i.e. combustion.

Pi? in particular, step 12 consists in burning part of the fuel RR1 and at least part of the component RR2 according to a first exothermic reaction r1.

The first reaction r1 exothermic ? of the type:

a RR1 b RR2 ? c CO2 d H2O (r1)

where RR1 and RR2 represent respectively the fuel and the component and where a, b, c, d are able to balance the first reaction r1.

The products of the first reaction r1 comprising carbon dioxide CO2 and water vapor H2O.

Furthermore, the first reaction r1 comprises among the reaction products hot combustion fumes F.

The hot combustion fumes F include at least in part the products of the first reaction r1.

The hot combustion fumes F include carbon dioxide CO2 and water vapor H2O.

CO2 carbon dioxide and H2O water vapor define the hot F combustion fumes.

To start phase 12 correctly to burn part of the fuel RR1 and at least part of the component RR2, the quantity? relative of? one and of? the other ? modulated so that the ratio between the component RR2 and the fuel RR1 ? higher than the stoichiometric ratio. For example, when the fuel RR1 ? methane CH4 and the component RR2 ? oxygen O2, the ratio of component RR2 to fuel RR1 (b / a) ? greater than 2 in moles.

When instead the fuel RR1 ? methane CH4 and the component RR2 ? air, the stoichiometric mass ratio is used, also called ?air-fuel dosage?.

Pi? in particular, when the fuel RR1 ? methane CH4 and the component RR2 ? air, the stoichiometric mass ratio between component RR2 and fuel RR1 ? above 17.

Furthermore, the ratio between the component RR2 and the fuel RR1 determines the flame temperature of the first reaction r1.

The flame temperature of the first reaction r1 determines the temperature of the hot combustion fumes F. To set the temperature of the hot combustion F fumes in a desired and pre-established range, or to set the flame temperature in a desired and pre-established range, ? modulated the amount? of the component RR2 in excess in the environment of the first reaction r1.

Greater ? the quantity? of the excess RR2 component, intended as an oxidizer, ? minor ? the flame temperature.

The addition of water vapor decreases the flame temperature.

The water vapor behaves as inert in the first reaction r1.

Pi? in particular, with reference to figures 2 and 3, steam and water act as inert materials, ie they take part in the first reaction r1 without any chemical involvement, but rather for controlling the flame temperature of the reaction. Advantageously, for the purposes of the present invention, the weight ratio between the remaining part of the fuel RR1 and the part of the fuel RR1 of the phase 12 of burning part of the fuel RR1 with at least part of the component RR2 ? between 3 and 10. Advantageously, this ratio ? between 3 and 5. In other words, the quantity? of fuel RR1 ? divided in such a way that a quantity? between about 10% and 33% ? used for phase 12, i.e. for the combustion of the fuel RR1 with the component RR2, while the remaining part of the fuel, i.e. between 66% and 90%, is used for the remaining phases of process 1.

Advantageously for the production of pure hydrogen, as illustrated in figure 5, the ratio by weight between the remaining part of the fuel RR1 and the part of the fuel RR1 of the burning phase 12 ? between 4 and 5.

Advantageously, the process according to the present invention in fact conveys only a part of the fuel RR1 to the combustion chamber and therefore to phase 12.

Advantageously, the part of the fuel RR1 conveyed to the phase 12, of burning part of the fuel RR1, is the one needed to start process 1.

The remaining part of reagent RR1 is not? combusted during process 1.

With reference to Figures 1, 2 and 3, step 12 of burning part of the fuel RR1 with at least part of the component RR2 comprises step 12? to extract part of the hot combustion fumes F from the reaction environment of the first reaction r1.

From phase 12, one moves on to phase 13, ie carrying out at least one reforming with water vapour.

Steam reforming takes place with at least part of the remaining fuel RR1 and part of the water H2O.

Steam reforming? carried out with at least part of the fumes F hot from combustion.

The reforming with steam takes place according to a second endothermic reaction r2.

Pi? in particular, the second reaction r2 for the purposes of the present invention takes the form of:

and RR1 f H2O ? gCO hH2 (r2)

where RR1 represents the fuel according to the present invention, while e, f, g, h are able to balance the second reaction r2.

The second reaction r2 includes among the reaction products carbon monoxide CO.

The second reaction r2 includes hydrogen H2 among the reaction products.

The hot combustion fumes F keep the temperature of phase 13 of reforming with steam high.

In this way there are no sudden changes in temperature such as to lead to the formation of hot spots or cooling zones in the environment of the second reaction r2. Reforming with steam, to which the hot combustion fumes F are added, thus keeps the speed high. of reaction, i.e. the conversion rate of the reactants of the second reaction r2 into the reaction products.

Furthermore, the addition of hot combustion fumes F reduces the time needed to complete the steps of process 1.

The presence of hot F fumes from combustion also avoids the need to to provide heat exchange surfaces to supply the thermal energy necessary for the second reaction r2, this reaction being of the endothermic type.

Further advantage given by the hot F fumes of combustion ? given by the fact that water vapor H2O is introduced into the environment of the second reaction r2, favoring the conversion of the reactants and therefore the production of hydrogen.

Further advantage given by the combustion fumes F ? given by the fact that in the environment of the second reaction r2 ? present carbon dioxide CO2 fed with the hot reaction fumes F.

Conversely, in an autothermal reforming, carbon monoxide CO would be present in the environment of the second reaction r2.

In this situation an excess of carbon monoxide CO could disadvantage the second reaction r2, being itself a reaction product.

The use of hot combustion fumes F in step 13 of carrying out a reforming with water vapor advantageously reduces the complexity? the process of converting fuel into separate streams of carbon dioxide CO2 and hydrogen H2, the related plant and associated costs.

Step 13 of performing a steam reforming further includes catalysts, such as nickel-based, to promote the production of hydrogen H2. With reference to Figures 1, 2 and 3, step 13 of carrying out a steam reforming is repeated more times, i.e. in successive stages.

By stage we must therefore mean a reforming stage 13.

Advantageously, the steps 13 of carrying out the reforming with steam take place in successive stages in sequence, in which a second reaction r2 takes place in each stage.

The fuel RR1 and the hot combustion fumes F feed the various stages.

Greater ? the number of stadiums, and pi? process 1 produces the same effects that would occur in an ideal process with an infinite number of phases 13.

Or major? the number of phases 13 carried out and more? the process of converting fuel into separate streams of carbon dioxide CO2 and hydrogen H2 is effective.

Pi? in particular, it is more? effective in terms of energy yields, i.e. production of hydrogen H2 in relation to the energy and fuel RR1 consumed, equal? of carbon dioxide CO2 captured. The effectiveness of the process? due to the fact that for each phase 13 the temperature is maintained almost? constant, because the heat exchange does not take place through convection and radiation as in conventional furnaces, but thanks to the hot combustion fumes F directly introduced into the environment of the second reaction r2.

In this way ? possible to optimize yields, that is, through process 1, ? It is possible to halve the lengths of the reactors in which the second reactions r2 occur, and to eliminate the external burners and heat exchangers of a conventional reforming furnace.

Furthermore, compared to a conventional process, the fuel RR1, the hot combustion fumes F, the water H2O and the heat are dosed in successive phases, thus being able to check the different components of the second reaction r2 and the optimal ratios between the reactants.

In this way, excesses of reagents are not generated which do not take part in the respective reaction and which would reduce the effectiveness of process 1.

From step 13, one passes to step 14, ie carrying out at least one water displacement of at least part of the carbon monoxide CO with part of the water H2O according to a third exothermic reaction r3.

The H2O water, prepared in phase 9, and in the liquid state, is adapted to feed at least one phase 14 to carry out a movement of water, as illustrated in figures 1, 2, and 3.

Pi? in particular, the third reaction r3 for the purposes of the present invention takes the form of:

i CO l H2O ? m CO2 n H2 (r3)

where CO represents carbon monoxide while i, l, m, n are able to balance the third reaction r3. The third reaction r3 includes carbon dioxide CO2 and hydrogen H2 among the reaction products.

Advantageously, step 14 of carrying out at least one water displacement of at least part of the carbon monoxide CO increases the yields of carbon dioxide CO2 of process 1.

Advantageously, step 14 of carrying out at least one displacement of water improves the effect of capturing carbon dioxide CO2 and producing H2 especially in the final stages of process 1.

Step 14 of carrying out at least one movement of water takes place at low temperatures, ie between 200 and 500°C.

Each step 14 of effecting a water displacement comprises catalysts, not shown.

Suitable catalysts are, for example, catalysts based on oxide, iron, copper, zinc, aluminum or a combination thereof.

The type of catalysts varies on the basis of the temperatures achieved in the environment of the third reaction r3, which in turn depend on the type of fuel RR1 and of the component RR2 of process 1. The temperatures achieved in the environment of the third reaction r3 are defined as low temperatures (low temperature shift or LTS) i.e. for temperatures between 200?C and 250?C, high temperatures (high temperature shift or HTS) i.e. for temperatures between 400?C and 450?C, and medium temperatures (MTC) i.e. for temperatures between 251?C and 399?C. Referring to Figure 3, step 14 of effecting a water displacement is repeated more times.

In these embodiments, the phases 14 take place, for example, in reactors arranged in series.

Each phase 14 comprises a sub-phase, not shown, of cooling the environment of the third reaction r3 between one phase 14 and the next, to optimize the water displacement yields.

Phase 14 of carrying out pi? times a displacement reaction ? for example advantageous when phase 14 comprises at least 2 stages, i.e. first a stage with a third reaction environment r3 at a high temperature (i.e. with HTS catalysts) and then a stage with a third reaction environment r3 at a low temperature (i.e. with catalysts LTS), with heat recovery before, during and after the various stages.

By stage is meant a phase 14 of effecting a displacement of water.

In embodiments not shown, the ambient cooling substep of the third reaction r3 is not performed. present in such a way as to simplify the construction of the plant and the reaction environment.

From phase 14, one passes to phase 15, ie producing steam of water to feed at least one phase 13 of carrying out a reforming with steam of water.

Step 15 of producing steam comprises the step, not shown, of extracting heat from at least one step between the steps of performing a steam reforming and performing a water displacement.

Pi? in particular, the phase of extracting heat takes place upstream of the environment of the third reaction r3, downstream of the environment of the third reaction r3, within the environment of the third reaction r3 or a combination thereof for at least one of the phases of carrying out a displacement of water, as illustrated in figures 1, 2, and 3.

Thereby ? It is possible to extract heat by cooling the fumes produced by the third exothermic reaction r3.

The phase of extracting heat takes place, for example, with heat exchangers.

When extraction takes place downstream of the second reaction r2 ? is it possible to reduce the temperature from the second reaction r2, which ? of the endothermic type to accelerate the speed? of reaction of step 13 to carry out a reforming with steam.

For example, in the case of methane CH4, before phase 14 the extraction of the water vapor takes place to bring the temperature inside the environment of the third reaction r3 from about 700-800°C to 250-350°C.

When the extraction takes place downstream of the third reaction r3 ? can recover heat from the third reaction r3 that ? of the exothermic type and make the energy consumption necessary to feed the entire process 1 more efficient, redistributing the heat produced by the entire process object of the present invention inside or outside the process itself.

The step 15 of producing water vapor, in addition to the step of extracting heat, comprises the step, not shown, of heating part of the water H2O with the extracted heat.

Step 15 further comprises the step of vaporizing part of the water H2O with the extracted heat.

Step 15 of producing water vapor ? such that the temperature of the third reaction r3 ? modulated so as to occur in the optimal range for the chosen catalyst (HTS, LTS, MTC).

The step 15 of producing water vapor comprises a step 15?, illustrated in figures 2 and 3, of modulating the quantity? of steam which feeds at least one stage of carrying out a reforming to control the second reaction r2 associated with stage 13.

Pi? in particular, the quantity? of steam? water? such that the steam-to-carbon ratio (f/e) of the second reaction r2 ? between 2 and 5.

By steam-to-carbon ratio (f/e) of the reaction we mean the ratio between the coefficients f and e of the second reaction r2.

Advantageously the steam-to-carbon ratio ? equal to about 2.5.

Modulating the steam-to-carbon ratio f/e ? possible to favor or slow down the second reaction r2.

The greater or lesser quantity? of steam? water? then determined in terms of the steam-to-carbon ratio. With reference to figures 2 and 3, the step of producing steam feeds the step 12 of burning part of the fuel RR1 and at least part of the component RR2 to improve the yields of process 1.

During phase 15 of producing steam? Water can? happen that the steam? water is produced in excess of the quantity? necessary in step 13 to carry out at least one steam reforming.

That is, during operation, can? happen that the steam-to-carbon ratio is higher than the optimal value established for a particular fuel RR1 and for the particular operating conditions.

In the case of methane CH4, for example, the vapor of? water can? be produced in excess, since? the hot combustion fumes F, which include water vapour, feed the second reaction r2.

The hot combustion fumes F of methane CH4 with oxygen O2 have a temperature between 900 and 1300?C, advantageously equal to about 1000?C.

Therefore, in these circumstances, the excess of water vapor produced is ? extracted in step 15 so as not to compromise the chemical reactions of process 1.

In embodiments not shown, the extracted heat is then advantageously used in other uses. In an industrial context for example, the excess of water vapor? suitable to be used for the production of heat or electricity.

In further embodiments, not shown, the excess of water vapor is conveyed to phase 16 of extracting carbon dioxide CO2 and hydrogen H2. For example, this solution ? adopted in absorption and stripping processes, to supply thermal energy necessary for the regeneration of a solvent in a closed cycle.

With reference to Figure 2, step 15 comprises a further step 15?? to modulate the amount? of water vapor for combustion, i.e. which feeds phase 12 of burning.

This solution allows to control and vary the flame temperature of the first reaction r1.

In further embodiments not shown, the steps 13, 14 and 15, respectively of carrying out a steam reforming, carrying out a water displacement and modulating at least part of the quantity extracted from the water vapor are carried out only once.

This solution is, for example, advantageous when there is a need? to carry out a process more? economic, albeit less efficient in thermodynamic terms, which can be associated with a more? compact.

Such as for example for applications in the marine transport sector for the on-board production of electricity from liquefied natural gas (LNG) with CO2 capture.

At least one of the first r1, second r2 and third r3 reactions comprise reaction residues RES.

The reaction residues RES include nitrogen N2.

The reaction residues RES include impurities and further elements in any case present in the reaction environment or in the reactants or in the products of the reactions r1, r2, r3.

The reaction residues RES include at least part of the reactants of the previous reactions, r1, r2 and r3, and which did not take part in the reaction or were in excess. The reaction residues RES include at least part of the products of the previous reactions, r1, r2 and r3, and which did not take part in the reaction or were in excess. The reaction residues RES also include the part of the fuel RR1 which did not take part in the reaction, ie which ? in excess.

The reaction residues RES also include the part of the RR2 component which did not take part in the reaction, ie which ? in excess.

In further embodiments not shown, the hot combustion fumes F comprise the reaction residues RES.

From phase 15, we pass to phase 16, i.e. to extract at least one of carbon dioxide CO2 and hydrogen H2.

L? extracted carbon dioxide CO2 and extracted hydrogen H2 define a stream of carbon dioxide CO2 and a stream of hydrogen H2, respectively.

Does step 16 of extracting at least one of carbon dioxide CO2 and hydrogen H2 further include step 16? to extract hydrogen H2 and phase 16?? to extract carbon dioxide CO2, as illustrated in figures 5, 6, and 7.

In this regard, step 16 of extracting at least one of carbon dioxide CO2 and hydrogen H2 comprises the step, not shown in the figures, of preparing at least one unit? of extraction for extracting said stream of carbon dioxide (CO2) and said stream of hydrogen (H2).

The unit of extraction ? for example, choice between a unit? of cryogenic extraction, a unit? of extraction of adsorption / desorption, a unit? of permeation at high pressure in membranes, a unit? extraction by solvent absorption or a combination thereof.

The unit of solvent absorption extraction uses, for example, amines as a solvent.

Such units? extraction plants are used for the extraction of hydrogen H2 or for the extraction of carbon dioxide CO2 or for both phases 16?and 16??, depending on the use of carbon dioxide CO2 and hydrogen H2 produced with the process 1.

The units?? of extraction can be chosen on the basis of costs and process conditions.

For example, the unit? extraction by absorption with amine-based solvents ? the "P? versatile and commercially employed under most process conditions.

For example, as for liquefied natural gas, in the case in which refrigeration is available from the regasification of a liquid, it is more? convenient to use them by adopting the? unit? of cryogenic extraction.

While in the event that it is necessary to produce mixtures containing one or more? of the products of the reactions of process 1, for example for the production of fuels, ? to prefer the use of a combination of different types of unit? of extraction.

In embodiments not shown other forms of unit? of extraction can be foreseen.

With reference to Figure 2, process 1 comprises a further step 20 of extracting hydrogen H2 from the products of at least one of the second (r2) and third (r3) reactions of the respective steps of carrying out a steam reforming and carrying out a displacement of water.

Thereby ? It is possible to increase the conversion rate of the respective second r2 and third r3 reactions, or both.

With reference to figures 4 to 7, the process 1 comprises a post-processing step 17 after the step 16 of extracting at least one of carbon dioxide CO2 and hydrogen H2.

In particular, with reference to figure 5, phase 16? to extract hydrogen H2 also includes the extraction of reaction residues RES.

That is, in order to obtain the desired degree of hydrogen H2 purity, additional extraction operations are required to filter and purify the hydrogen H2 to the desired level.

Pi? in detail, again with reference to figure 5, does the post processing phase 17 comprise at least one phase 17? to extract residues RES of the third reaction r3, in which phase 17? to extract residues RES of the third reaction r3 ? after stage 16? to extract hydrogen H2.

Phase 17? extract RES residues of the third reaction r3 ?, for example, carried out by pressure swing adsorption/desorption, also called PSA).

Thereby ? It is possible to prepare pure hydrogen H2 18, i.e. without reaction residues RES.

To this end, at least one unit? of extraction, not illustrated in figure 5, ? fixed between phase 16? to extract hydrogen H2 and phase 17? to extract RES residues of the third reaction r3.

In further embodiments not shown, a similar process is expected for carbon dioxide CO2. That is, in order to obtain the desired degree of purity of carbon dioxide CO2, additional extraction operations are necessary to filter and purify the carbon dioxide CO2 to the desired level.

Pi? in detail, does post processing phase 17 include at least one phase 17? to extract residues RES of the third reaction r3, in which phase 17? to extract residues RES of the third reaction r3 ? after stage 16?? to extract carbon dioxide CO2.

Thereby ? It is possible to prepare carbon dioxide CO2 without reaction RES residues.

In further embodiments, not shown, after step 16?? to extract CO2 carbon dioxide, this ? subjected to a liquefaction step.

L? carbon dioxide liquefied CO2 ? then, for example stored, in underground or submarine basins or converted at least in part into new chemical compounds, for example in carbon capture & utilization (CCU) applications.

In further embodiments, not shown, after step 16? to extract hydrogen H2, this ? subjected to a compression phase, and to a liquefaction phase, to be stored.

With reference to figure 6, the post processing phase 17 comprises at least one phase 17?? to add part of the fuel RR1 to part of the hydrogen H2 to prepare an enriched fuel 18?.

The quantity? of fuel RR1 addition defines the degree of ?enrichment? fuel up to the desired value.

Or major? the quantity? by weight of fuel RR1 added and greater? the degree of enrichment of the fuel.

Thereby ? It is possible to produce fuels with different degrees of enrichment.

For example, if the fuel RR1 ? methane CH4, a different degree of fuel enrichment makes it possible to use the same existing infrastructures (such as the SNAM natural gas distribution network) but to produce, when used, lower carbon dioxide emissions thanks to the presence of hydrogen.

With reference to figure 7, the post processing phase includes the phase of preparing at least one unit? 19 of electricity generation, and a reagent RR3. The RR3 reagent? a mixture comprising fuel RR1.

In embodiments not shown, the RR3 reagent is a mixture comprising the fuel RR1, at least one component RR2 and water vapour.

The RR3 reagent? for example methane or natural gas to which oxidizing agents and water vapor are added.

Mixtures of this kind are suitable for being added to combustion processes to control the flame temperature of the fuels themselves.

Thus, for example, it is possible to use a natural gas turbine as a hydrogen turbine.

After the phase of preparing at least one unit? 19 for generating electric energy, and a reactant RR3, follows the step of adding at least one of a choice between part of the fuel RR1 and part of the third reactant RR3, or a combination thereof, according to the respective steps 17?? and 17???.

The addition of the first RR1 and/or the third RR3 hydrogen reagent H2 ? used to prepare a mixture suitable for feeding the unit? 19 of electricity generation 18??.

These solutions have the advantage of not substantially modifying the current energy generation plants, with the benefit of reducing, up to zeroing, the CO2 emissions relating to the kWh of energy produced. Advantageously, in the production of fuel for energy production 18??, the residues RES of the third reaction r3 comprise nitrogen N2.

The presence of nitrogen N2 in enriched fuel 18? lowers the flame temperature of the fuel itself.

Thereby ? possible to have control over the combustion for the production of electricity 18??. The unit 19 of electricity generation ? selected, for example, from a turbocharger, turbine, power block, fuel cell, or combination thereof. Referring to figure 3, ? illustrated, by way of example, the process 1 in the event that the fuel RR1 ? methane CH4, the RR2 component? oxygen O2, i.e. RR2 ? an oxidizer.

In particular, in phase 9, phase 10 and in phase 11, respectively, water H2O, methane CH4 and oxygen O2 are prepared.

Subsequently in phase 12 the combustion of part of the methane CH4 and at least part of the oxygen O2 takes place according to the first exothermic reaction r1:

CH4 2 O2 ? CO2 2 H2O (r1)

where a and c are equal to 1, while b and d are equal to 2. The products of the first reaction r1 include carbon dioxide CO2 and water H2O.

The products of the first reaction r1 comprise water H2O in the form of steam and reaction residues RES and hot combustion fumes F.

The hot F fumes of combustion include carbon dioxide CO2 and hydrogen H2.

After phase 12, are the hot combustion fumes F extracted in phase 12? to feed and support step 13 of reforming with steam. Phase 13 of carrying out at least one reforming with water vapor of at least part of the remaining part of methane CH4 with at least part of the hot combustion fumes F takes place according to a second endothermic reaction r2:

CH4 + H2O ? CO 3H2 (r2)

where e, f and g are equal to 1 and h ? equal to 3.

The products of the second reaction r2 include carbon monoxide CO and hydrogen H2.

That is, step 13 of performing a steam reforming produces syngas, a mixture of carbon monoxide CO and hydrogen H2.

The second reaction r2 further comprises reaction residues RES and water H2O.

A further advantage given by the addition of hot F combustion fumes (ie H2O and CO2) to step 13 of carrying out a steam reforming ? given by the fact that the water H2O ? a reactant of the second reaction r2.

In this way the quantity is reduced? of water H2O to be produced and the same carbon dioxide CO2 pu? react with methane CH4 with the same catalysts, for example, based on nickel.

This reaction, called dry reforming, takes place according to a fourth reaction r4:

CO2 CH4 ? 2 H2 2 CO (r4) where carbon dioxide CO2 reacts with methane CH4.

The products of the fourth reaction r4 include hydrogen H2 and carbon monoxide CO.

In the reaction environment of the second reaction r2, i.e. in step 13 of carrying out a reforming, the fourth reaction r4 also takes place.

Such a situation? advantageous for the process 1 since? improve the quantity? of hydrogen H2 extracted from process 1.

Other advantage? given by the fact that the fourth reaction r4 advantageously reduces the phase of extraction of carbon dioxide CO2, since? the fourth reaction r4 consumes part of the carbon dioxide CO2.

After step 13, one passes to step 14 of carrying out at least one displacement of water of the carbon monoxide CO according to a third exothermic reaction r3:

CO H2O ? CO2 + H2 (r3)

where i, l, m and n are equal to 1.

The products of the third reaction r3 comprising carbon dioxide CO2 and hydrogen H2.

The products of the third reaction r3 comprising reaction residues RES.

After step 14, it passes to step 15 of producing steam to feed at least one step 13 of carrying out a reforming with water steam, subtracting heat from at least one step 14 of carrying out a displacement of water. After phase 15, one passes to phase 16 of extracting at least one of the carbon dioxide CO2 and the hydrogen H2.

The example relating to methane CH4 in figure 3 involves phases which are repeated over and over? times.

In embodiments not shown, steps 13, 14 and 15 are to be repeated only once.

These solutions are preferable, for example, for small-sized plants, with small flow rates or in which the final efficiency is not? considered an essential parameter of the process.

In embodiments not shown, the steps of carrying out at least one reforming with steam and of carrying out at least one displacement of water have a different order, so as to make process 1 more efficient in terms of quantity of water. of carbon dioxide CO2 and hydrogen H2 extracted at the end of the process depending on the type of fuel RR1 and component RR2 used.

The products of the first r1, second r2 and third r3 reactions are extracted downstream of the respective phase 12 of burning part of RR1 and RR2, 13 of carrying out at least one reforming with steam and 14 of carrying out at least one displacement of? water, one or more times.

These extractions define the intermediate extractions of process 1.

Intermediate extractions make it possible to maximize the efficiency of the fuel conversion process into separate streams of carbon dioxide CO2 and hydrogen H2.

The process 1 according to the invention achieves the intended aims and achieves important advantages.

A first advantage of the process? given by the fact ? is it possible to separate the carbon dioxide in favorable conditions cio? at pressure and/or mole fraction pi? high compared to post-combustion processes.

Another advantage according to the invention? represented by the possibility to adapt the process to different situations of use.

Another advantage of the present invention ? that of creating a process that can be easily modified and adapted also to conventional processes, such as for example in the case of gas turbines.

Another advantage of the process according to the invention? given by the scalability?, that is, the process 1 ? also replicable in different sizes, while maintaining the characteristics of versatility? and flexibility.

Additional advantage? given by the reduction of carbon dioxide CO2 emissions of the products based on hydrogen H2 obtained with the process object of the present invention.

The process 1 can? be advantageously used in sectors with a high production of carbon dioxide, improving the ecological footprint of companies operating, for example, in the transport, petrochemical and energy production sectors, as in the case of natural gas combined cycles (NGCC).

Another advantage of the process object of the present invention ? given by the fact that most of the fuel RR1 is not ? subjected to phase 12 in which combustion takes place.

In fact, the fuel RR1, subjected to the process object of the present invention, is purged of the quantity? of carbon dioxide CO2 contained in it so that, the subsequent processing of the product obtained from process 1, develop a lower quantity? of carbon dioxide CO2, zero at the limit. Additional advantage? given by the fact that ? Is it possible to make the steam reforming process more efficient by dividing the process into phases, reducing the quantity? of the hot combustion fumes F to be introduced in each phase 13 of carrying out a reforming with steam. Other advantage? given by the fact that the control pi? punctual of the temperature in the various phases of the process improves the thermodynamic efficiency and avoids the formation of hot spots.

Additional advantage? given by the fact that ? is it possible to have more control? punctual on the conversion rate of each single reaction, r1, r2, and r3, of the process and consequently act in order to bring each reaction as much as possible? close as possible to the conversion thermodynamic equilibrium, which corresponds to the insurmountable thermodynamic limit.

Another advantage of the process 1 in the pi configuration? stadiums ? given by the increase in the effect of capturing carbon dioxide CO2 and producing H2 in the final stages of the process.

The increase of the capture effect ? given by the fact that? CO2 carbon dioxide in phase 16?? it is extracted in non-negligible concentrations from a gas under pressure.

Additional advantage? represented by the possibility to adapt the process also to industrial plants already? in use, being able to take advantage of the versatility? of process 1 to create retrofit solutions.

For example, the process object of the present invention ? suitable for the combined production of pure hydrogen and electricity produced by a gas turbine powered by enriched fuels.

Further advantage of the present invention? the possibility? to have a process for the production of decarbonised streams of hydrogen H2, i.e. such as to be obtained starting from combustible products from which ? separate the carbon dioxide.

Still another advantage? given by the conversion of fuels, such as fossil fuels, into mixtures with low environmental impact.

Claims (13)

1. Process of conversion of fuel (RR1) into separate streams of carbon dioxide (CO2) and hydrogen (H2), including the steps of: - prepare a fuel (RR1), a component (RR2), and water (H2O); - burning part of said fuel (RR1) and at least part of said component (RR2) according to a first exothermic reaction (r1), said first reaction (r1) comprising among the reaction products hot combustion fumes (F); - carry out a steam reforming of at least part of the remaining part of said fuel (RR1) with part of said water (H2O) and part of said hot combustion fumes (F) according to a second endothermic reaction (r2), called second reaction (r2) comprising among the reaction products carbon monoxide (CO) and hydrogen (H2); - carry out a water displacement of part of said carbon monoxide (CO) with part of said water (H2O) according to a third exothermic reaction (r3), said third reaction (r3) comprising among the reaction products carbon dioxide (CO2 ) and hydrogen (H2); - producing steam to feed at least one of said step of carrying out a reforming with steam; - extracting at least one of said carbon dioxide (CO2) and said hydrogen (H2), said extracted carbon dioxide (CO2) and said extracted hydrogen (H2) defining a respective stream. 2. Process according to claim 1, characterized in that said step of burning part of said fuel (RR1) and at least part of said component (RR2) comprises the step of extracting part of said hot combustion fumes (F). 3. Process according to claim 1, characterized in that said step of producing steam comprises the steps of: extracting heat from at least one phase between the phases of performing a steam reforming and performing a water displacement; - heating and vaporizing part of said water (H2O) with said extracted heat. 4. Process according to claim 3, characterized in that said step of extracting heat takes place upstream of the environment of the third reaction (r3), downstream of the environment of the third reaction (r3), within the environment of the third reaction (r3) or a combination thereof for at least one of said steps of effecting a water displacement. 5. Process according to claim 1, characterized in that the weight ratio between said remaining part of said fuel (RR1) and the part of said fuel (RR1) of said burning phase ? between 3 and 10. 6. Process according to claim 1, characterized in that it comprises a step of extracting hydrogen (H2) from the products of at least one of said second (r2) and third (r3) reactions of said respective steps of carrying out a reforming of steam d? water and effecting a water displacement to increase the conversion rate of said respective second (r2) and third (r3) reactions. 7. Process according to claim 1, characterized in that said step of producing steam of water comprises a step of modulating the quantity? of steam which feeds at least one of said phase of carrying out a reforming to control at least one of said second reaction (r2), in which said quantity? of steam? water? such that the steam-to-carbon ratio (f/e) of said second reaction (r2) ? between 2 and 5. 8. Process according to claim 1, characterized in that it comprises a pretreatment step, said pretreatment step comprising a gasification step of said fuel (RR1) to bring at least part of said fuel (RR1) into a gaseous state before starting the process. 9. Process according to claim 1, characterized in that said fuel (RR1) is a fuel selected from the group including methane, natural gas, liquid natural gas (LNG), biogas, coal, biomass, methane-containing blend, methanol, propane, diesel, aircraft fuel, kerosene, ammonia, fossil fuel, or a combination thereof. 10. Process according to claim 1, characterized in that said component (RR2) ? a component selected from the group comprising oxygen, air, steam, water, or a combination thereof. 11. Process according to claim 1, characterized in that at least one of said first (r1), second (r2) and third (r3) reactions comprise reaction residues (RES) comprising nitrogen (N2). 12. Process according to claim 1, characterized in that said step of extracting at least one of said carbon dioxide (CO2) and said hydrogen (H2) comprises the step of preparing at least one unit? of extraction for extracting said stream of carbon dioxide (CO2) and said stream of hydrogen (H2). 13. Process according to claim 1, characterized in that it comprises a post-processing step after said step of extracting at least one of said carbon dioxide (CO2) and said hydrogen (H2).