ES2253990A1 - Method for producing hydrogen and system that applies said method - Google Patents

Abstract

Method for producing hydrogen characterised in that it includes the stages of evaporating water (1) by provision of energy (14,16,19) from renewable sources and of carrying out dissociation of said water, in liquid (1) or vapour (5) form, by provision of energy (14,16,19,23) from renewable sources. System that applies said method, characterised in that it includes means (3) for supplying water (1), means (4,21,25) for producing steam (5) from said water (1) by using energy (14,16,19) from renewable sources and means (8) for dissociation of said water (1), in liquid or vapour form, using energy (14,16,19,23) from renewable sources. It is a sustainable and clean method and system.

Description

Procedure for obtaining hydrogen and system which applies said procedure.

The present invention relates to a procedure for obtaining hydrogen from water, with contribution of energy from renewable sources.

Background of the invention

Hydrogen is considered a source of energy.  very interesting due to its high energy content and its low environmental impact, since its combustion produces only Water.

The use of hydrogen as a source of energy in replacement of primary energy sources such as oil, gas natural or coal, will enable the development of a system energy efficient and emission-free, since it will allow a drastic reduction in carbon dioxide emission from the combustion of said fossil fuels and, for Therefore, the improvement of air quality, the health of the planet and the reduction of the greenhouse effect.

The generation of hydrogen in large quantities to meet the current demand for fossil fuels, it must be carried out from energy from sources renewable, that is, from energy from sources that they are continuously regenerated by natural processes, and that, by Therefore, they are clean and do not consume finite resources. Only from In this way, the development of a system can be guaranteed Energy truly sustainable and clean.

Currently hydrogen is obtained at the level industrial by steam reforming of hydrocarbons, such as natural gas or light distillates, and by electrolysis of the water.

Hydrocarbon steam reforming is based in the reaction of water vapor and high temperature gas over a catalyst

The system of obtaining hydrogen by Hydrocarbon steam reforming is used in industry when the production of large quantities of hydrogen, however, has the drawbacks of using as raw material non-renewable resources such as fuels fossil origin, and that constitutes a system that contributes to the emission of carbon dioxide and, therefore, to the effect greenhouse. Therefore, it is not a valid option for sustainable and clean hydrogen production in large quantities.

Water electrolysis consists of the release of hydrogen and oxygen contained in the water in form  liquid, through the use of electricity.

Although it is known that energy electrical can be obtained from energy from sources renewable, electrolysis has the disadvantages that it is a process of obtaining very slow hydrogen, which requires the purification of the liquid water used and which, in addition, implies a high consumption of electricity per liter of hydrogen produced. For all this, the use of the technology of the electrolysis has so far been limited to the production of small  amounts of hydrogen

On the other hand, we must bear in mind that known systems for obtaining hydrogen by electrolysis they have the disadvantage that they are designed to be always used with water of continental origin, constituting said water an increasingly scarce resource, which hinders the application of such technology for the production of large amounts of hydrogen

There are no known procedures and systems of obtaining hydrogen in large quantities that they use, in all its stages, only energy from renewable sources, that do not generate pollutants and that are also designed to be used or not with water of origin other than continental.

Description of the invention

The objective of the present invention is to solve the aforementioned inconveniences, developing a procedure and system for obtaining hydrogen in large quantities that use only energy from renewable sources and not It generates pollutants.

In accordance with a first aspect of the present invention, a procedure that is characterized by the fact that he understands the stages of:

to)

Evaporate water with energy input  from renewable sources.

b)

Carry out the dissociation of said water, in liquid or steam form, by providing energy from renewable sources.

Thanks to these characteristics, the procedure  of the present invention has the advantage that it enables the production of large quantities of hydrogen from pure water obtained by evaporation, either of water of continental origin or marine, and from energy from renewable sources. Therefore, it is a sustainable and clean procedure, since it does not generate pollutants.

Another advantage of the procedure of the invention is that water vapor, obtained by the contribution of energy from renewable sources, it constitutes, in addition to the basic raw material to carry out the production of hydrogen, an important source of heat energy that can easily be transformed into electrical energy to apply in the  dissociation of said water, either in liquid or vapor form.

Preferably, said water is marine. Of this mode, hydrogen production is not limited to the availability of a resource as scarce as water continental.

Preferably, said seawater being said energy of stages a) and b) comes at least from the waves of the sea.

Systems for obtaining sea wave energy, particularly the one protected by patents ES 2170029 and P200302809, the latter unpublished, which make it possible to obtain large amounts of energy electrical, which can be used to carry out the procedure for obtaining hydrogen of the present invention.

Alternatively, said energy from steps a) and b) it comes from at least the sun, preferably from a tower-type solar thermal power plant that, in this case, evaporates the water from the system itself and obtains electricity from the steam obtained with said water.

Also alternatively, said water being marine, said energy from stages a) and b) proceeds at least of the sun and the waves of the sea. In this way, you can take advantage of the energy from two renewable sources, solar and Obtained from the oceans.

Again alternately, said energy of the stages a) and b) comes at least from the sun and said water. From In this way, energy from two sources can be used renewable, which in this case are solar and hydraulic energy of the water involved in the procedure itself.

According to a first preferred embodiment, then from step a) the process of the invention comprises the step of condensing the water vapor obtained, and the dissociation of said Water in liquid form is carried out by electrolysis.

Preferably, the dissociation of said water in steam form is carried out by a process of reforming said steam which consists of superheating the water vapor to temperatures above 900 ° C, at which the molecules of Water dissociates. Said reforming process obtains a yield of hydrogen superior to that of electrolysis.

In accordance with a second aspect of the present invention, a system for obtaining hydrogen is proposed according to the described procedure, which is characterized by the fact comprising means for obtaining water, means for obtaining steam of said water from energy from renewable sources and means for the dissociation of said water, in liquid or vapor form, from energy from sources renewable.

Thanks to these characteristics, the system of the  The present invention enables the production of large quantities of hydrogen from pure water obtained by evaporation, either of water of continental or marine origin, and from energy from renewable sources. Therefore, it is about a system that, like the procedure described, is sustainable and clean, since it does not generate pollutants.

Preferably, said means for obtaining of steam comprise a field of heliostats and a solar receiver, located on top of a tower, through which said water circulates.

According to a preferred embodiment, said means for obtaining steam comprise means for obtaining energy from the sun, means for water storage in an airtight enclosure and means to heat said water stored

Advantageously, said means for obtaining of energy from the sun include parabolic concentrators, lenses or mirrors that concentrate sunlight, and said means for heating said water comprise carbon bars in contact with said water, said bars being heated by said energy coming from the sun

According to a preferred embodiment, said means for the dissociation of said water in liquid form comprise a hydrogen and oxygen generator by electrolysis.

Preferably, said means for water dissociation in the form of steam comprise a system of hydrogen production by reforming said steam which, as It has already been mentioned, it consists of overheating said water vapor to temperatures above 900 ° C, at which water molecules They dissociate.

Preferably, said system comprises means to obtain electrical energy from energy from renewable sources In this way, the electrical energy obtained is supply the teams responsible for carrying out the water dissociation, in liquid or vapor form.

Advantageously, the system comprises means for compress air with the energy obtained from the water itself system, means for storing said compressed air, means for heating said air from energy from sources renewable and means to obtain electricity from said compressed air.

Thanks these features, storage compressed air is a form of storage of energy from these renewable sources that will be available for use in the system itself when considered necessary, when converting the energy contained in that air into electric power by means of a pneumatic motor and an alternator or Electric generator. The expansion suffered by compressed air with its heating increases the energy contained in said air and therefore the electrical energy finally obtained at start from him.

Preferably, said means for obtaining of electric power comprise a system for obtaining energy from the waves of the sea, as described by the patents ES 2170029 and P200302809, the latter unpublished, which makes it possible to obtain large amounts of electrical energy from renewable energy obtained from the oceans.

Also preferably, said means of Obtaining electric power include steam turbines and electric generators, said steam being obtained from said water from energy from renewable sources, preferably solar energy. In this way, the heat energy contained in the system's water vapor for Electricity production.

Advantageously, said means for obtaining Electric power include hydraulic turbines and generators electrical, the water that moves said turbines being said system. In this way, the hydraulic energy of the water is used of the system itself.

According to a preferred embodiment, said means of  obtaining electrical energy comprise said steam turbines and electric generators, means for raising said steam to a certain height, means for condensing said steam and said hydraulic turbines and electric generators for energy electric from the potential energy stored by water from the condensation of said steam at said height.

The production of high temperature steam that takes place in the system of the invention, enables, in a way natural, the height elevation of a very important volume of water that, after condensation, can be used to produce electricity again.

According to another preferred embodiment, said means to obtain electrical energy they comprise first hydraulic turbines and electric generators, means to lift said water at a certain height and second turbines Hydraulics and electric generators to obtain electrical energy from the potential energy stored by said water to said height.

Thanks these features, storage of water at a certain height constitutes a form of storage of energy from these renewable sources which will be available for use on the system itself when consider necessary, when converting the potential energy it contains said water in electrical energy by means of said turbines Hydraulics and electric generators.

Brief description of the drawings

For greater understanding of how much has been exposed some drawings are accompanied in which, schematically and only to non-limiting example title, three practical cases are represented of realization.

In these drawings,

Figure 1 is a schematic of a first preferred embodiment of the system for obtaining hydrogen from the present invention in which water is marine and energy is it obtains from the waves of the sea and the water of the system itself.

Figure 2 is a schematic of a second preferred embodiment of the system for obtaining hydrogen from the present invention in which water is marine and energy is it gets from the sun and from the water of the system itself.

Figure 3 is a schematic of a third preferred embodiment of the system for obtaining hydrogen from the present invention in which water is marine and energy is it gets from the sun, from the waves of the sea and from the water itself system.

Description of three preferred embodiments

Figure 1 shows a first embodiment preferred of the system of the present invention in which water 1 it is obtained from sea 2 through a conduit 3 that transports said marine water 1 to an airtight enclosure 4 where it is carried evaporate out

The evaporation of marine water 1 also generates of steam 5 of water 1, a water residue 6 concentrated in salts which is stored in a large saline 7 where the crystallization of said salts for later exploitation.

The represented system comprises a plurality of equipment 8 where steam dissociation 5 is carried out, superheated to a temperature equal to or greater than 900 ° C, by The water vapor reform process. The reform process of water vapor constitutes a dissociation process that presents the advantage over electrolysis that it is faster, so It has a superior hydrogen yield.

Water dissociation 5 of water 1 generates hydrogen 9, oxygen 10 and a pure water residue 11, which are stored in tanks 12 for later distribution.

The energy needed to carry out the process of obtaining hydrogen from the system represented in the Figure 1 is obtained from renewable sources such as sea waves 2 and water 1 of the system itself.

To get the energy of the waves of the sea 2, you  has installed a buoy installation 13 according to the system protected by patents ES 2170029 and P200302809, the latter does not published. This system converts the energy from the movement of the buoys due to the effect of sea waves 2 on energy electric 14, so that, for example, with a park of 1000 buoys 13 it is possible to produce 10 Mwh of electrical energy 14.

To obtain energy from water 1 of own system, hydraulic turbines 15 have been arranged that generate mechanical energy from the flow of water 1 that circulates by driving 3 of the system. The mechanical energy produced by the turbines 15 is transformed into electrical energy 16 by electric generators 17, or used to generate directly compressed air by compressors arranged in the inside of said turbines.

In the embodiment described, the energy electric 16 of generators 17 is used to compress air which is stored in deposits 18. Such deposits 18 they constitute a form of storage of the energy coming of water 1 of the system itself, since compressed air can be transformed into electricity 19, at the desired time, by pneumatic motors and alternators or electric generators 20. In this way, the storage of electrical energy is avoided by batteries, whose components are a source of waste pollutants, such as heavy metals.

Figure 2 shows a second embodiment preferred of the present invention in which the energy sources renewable to carry out the obtaining of hydrogen 9, are the sun and water 1 of the system itself.

The system of Figure 2 differs from that of the  Figure 1 in which the conduit 3 of marine water 1 transports said water 1 to a tower 21 where a receiver is arranged solar through which water circulates 1. This solar receiver serves as heat exchanger transferring concentrated solar energy to water 1 to transform it into superheated steam 5.

In the embodiment described, steam 5 superheated is sent to a steam turbine 22 that converts the heat energy of steam in mechanical energy. That energy mechanics is transformed into electrical energy 23 by a electric generator 24.

The solar receiver located in tower 21 concentrates sunlight from a field of heliostats 25 that  It consists of mirrors with tracking that constantly direct the radiation captured, to said solar receiver.

The set of elements formed by the field of  heliostats 25, solar tower / receiver 21 and turbine 22 of steam 5 and electric generator 24, forms the basis of a central thermal solar tower type, whose operation and performance is widely known in the state of the art.

The system described in this second embodiment it has the advantage that the same steam 5 produced by said solar thermal power plant is used to obtain hydrogen 9 by the process of dissociating said steam 5 by reform.

Figure 3 shows a third embodiment preferred of the present invention in which the energy sources renewable to carry out the obtaining of hydrogen 9, are the sun, water 1 of the system itself and the waves of the sea 2.

As can be seen in Figure 3, the system  of this third embodiment comprises a solar thermal power plant like the one in figure 2, an installation of buoys 13 like the one in the Figure 1 and a system of hydraulic turbines 15 and generators electrical 17, 20 like those in figures 1 and 2.

Although he has not been represented, anyone of the three embodiments represented could incorporate means to condense the steam 5 of marine water 1 obtained for this mode, carry out the dissociation of pure water in liquid form, through the electrolysis process. However, said process of electrolysis, has the disadvantage regarding the process of steam reform, that is slower, so the performance Obtaining hydrogen is inferior.

Similarly, although it has not been represented, in any of the embodiments of figures 2 and 3, the solar tower / receiver 21 could be replaced by a parabolic concentrator whose function is to concentrate the solar energy using a disk-shaped bowl or reflector. In this case, the light concentrated by the parabolic concentrator it would heat, for steam production 5, carbon bars arranged in tightly sealed tanks in which would store water 1. The heat energy of said steam 5, could also be used for the production of electrical energy through the corresponding turbines and generators electric

Surprisingly, the system of the present invention has the advantage over obtaining systems of hydrogen known in the state of the art, which allows the production of large quantities of hydrogen from water marine or sweet and energy from renewable sources, all This without generating pollutants, so it is a system sustainable and clean.

In order to demonstrate self-reliance energy of the system of the present invention, are contributed to Below are two numerical examples in which the energy balance and hydrogen production of two system accomplishments.

Example 1 System for obtaining hydrogen from energy coming from the waves of the sea System energy needs

On average, for the evaporation of 1.1 liters / hour of water 1 Kwh of energy is necessary.

Similarly, on average, with 1 Kwh of energy dissociates 0.152 liters / hour of water and 181 is obtained liters / hour of hydrogen.

Therefore, for every 1 Kwh of energy that is used in the water evaporation process, 7.23 Kwh are needed  of energy for the dissociation of said water.

It follows that, in percentage, of 100% of system energy needed, on average, 12.15% is destines to evaporate the water and the remaining 87.85% to the process of dissociation of said water.

Energy supply from energy coming from sea waves

With an installation of 1000 buoys it is possible to obtaining 10 Mwh of electrical energy from energy coming from the waves of the sea.

In view of the energy percentages of the system mentioned above, it follows that from 10 Mwh obtained, 1,215 Mwh are destined to evaporate the water and 8,785 Mwh to the dissociation of said water.

System hydrogen production

On average, with 1 Kwh consumed in the dissociation process 181 liters / hour of hydrogen.

Therefore, with 8,785 Mwh of energy from system intended for the dissociation process, will be obtained approximately 1.5 million liters of hydrogen / hour.

Example 2 System for obtaining hydrogen from energy coming from the sun System energy needs

On average, for the evaporation of 1.1 liters / hour of water 1 Kwh of energy is necessary.

Similarly, on average, with 1 Kwh of energy dissociates 0.152 liters / hour of water and 181 is obtained liters / hour of hydrogen.

Therefore, for every 1 Kwh of energy that is used in the water evaporation process, 7.23 Kwh are needed of energy for the dissociation of said water.

It follows that, in percentage, of 100% of system energy needed, on average 12.15% is destines to evaporate the water and the remaining 87.85% to the process of dissociation of said water.

Energy supply from energy from the Sun

With a tower-type solar thermal power plant it is possible to obtain 50 Mwh electrical energy from energy coming from the sun

Because the solar thermal power plant produces the electrical energy from water vapor generated in the solar receiver, in this case it can be used to dissociate water 100% of the energy obtained by the plant, that is 50 Mwh electric power

System hydrogen production

On average, with 1 Kwh consumed in the dissociation process 181 liters / hour of hydrogen.

Therefore, with 50 Mwh of system power intended for the dissociation process, approximately 9 million liters of hydrogen / hour.

Claims (25)

1. Procedure for obtaining hydrogen (9) characterized by the fact that it comprises the steps of:

to)

Evaporate water (1) with input from energy (14,16,19) from renewable sources.

b)

Carry out the dissociation of said water, in liquid form (1) or steam (5), by contribution of energy (14,16,19,23) from renewable sources.

2. Method according to claim 1, characterized in that said water (1) is marine. 3. Method according to claim 2, characterized in that said energy of stages a) and b) comes at least from the waves of the sea (2). 4. Method according to claim 1, characterized in that said energy of steps a) and b) comes from at least the sun. 5. Method according to claim 2, characterized in that said energy of stages a) and b) comes at least from the sun and the waves of the sea (2). Method according to claim 1, characterized in that said energy of stages a) and b) comes from at least the sun and said water (1). Method according to claim 1, characterized in that after stage a) it comprises the stage of condensing the steam (5) of water obtained. Method according to claim 7, characterized in that the dissociation of said water in liquid form (1) is carried out by electrolysis. Method according to claim 1, characterized in that the dissociation of said water in the form of steam (5) is carried out by a process of reforming said steam (5). 10. System for obtaining hydrogen according to any of the preceding claims, characterized in that it comprises means (3) for obtaining water, means (4,21,25) for obtaining steam (5) of said water (1) from energy (14,16,19) from renewable sources and means (8) for the dissociation of said water (1), in liquid or vapor form, from energy (14,16, 19.23) from renewable sources. 11. System for obtaining hydrogen according to claim 10, characterized in that said means for obtaining steam comprise a field of heliostats (25) and a solar receiver (21), located above a tower, by the circulating said water (1). 12. System according to claim 10, characterized in that said means for obtaining steam (5) comprise means for obtaining energy from the sun, means for storing water (1) in a hermetic enclosure ( 4) and means for heating said stored water (1). 13. System according to claim 12, characterized in that said means for obtaining energy from the sun comprise parabolic concentrators of sunlight. 14. System according to claim 12, characterized in that said means for obtaining energy from the sun comprise lenses that concentrate sunlight. 15. System according to claim 12, characterized in that said means for obtaining energy from the sun comprise mirrors that concentrate sunlight. 16. System according to claim 12, characterized in that said means for heating said water comprise carbon bars in contact with said water (1), said bars being heated by said energy from the sun. 17. System according to claim 10, characterized in that said means for dissociating said water in liquid form (1) comprise a hydrogen generator (9) and oxygen (10) by electrolysis. 18. System according to claim 10, characterized in that said means for the dissociation of water in the form of steam (5) comprise a system (8) for producing hydrogen (9) by reforming said steam (5). 19. System according to claim 10, characterized in that it comprises means (13,15,18,20,22,24) for obtaining electrical energy (14,16,19,23) from energy from renewable sources . 20. System according to claim 19, characterized in that it comprises means for compressing air with the energy (16) obtained from the water (1) of the system itself, means (18) for storing said compressed air, means for heating said air from energy from renewable sources and means (17) for obtaining electrical energy from said compressed air. 21. System according to claim 19, characterized by the fact that said means for obtaining of electric power comprise a system (13) for obtaining of energy from the waves of the sea (2) 22. System according to claim 19, characterized in that said means for obtaining electric power comprise steam turbines (22) and electric generators (24), said steam (5) being obtained from said water (1) a from energy from renewable sources. 23. System according to claim 19, characterized in that said means for obtaining electrical energy comprise hydraulic turbines (15) and electric generators (17), the water (1) moving said turbines (15) being that of said system. 24. System according to claims 22 and 23, characterized in that said means for obtaining electrical energy comprise said steam turbines (22) and electric generators (24), means for raising said steam (5) to a certain height , means for condensing said steam (5) and said hydraulic turbines (15) and electric generators (17) to obtain electrical energy from the potential energy stored by the water (1) at said height from the condensation of said steam ( 5). 25. System according to claim 23, characterized in that said means for obtaining electrical energy comprise first hydraulic turbines and electric generators, means for raising said water to a certain height and second hydraulic turbines and electric generators to obtain electrical energy from the potential energy stored by said water (1) at said height.