EP2367753A1

EP2367753A1 - Method and plant for providing an energy carrier using carbon dioxide as a carbon supplier and using electricity

Info

Publication number: EP2367753A1
Application number: EP09781782A
Authority: EP
Inventors: Roland Meyer-Pittroff; Peter Grauer
Original assignee: Silicon Fire AG
Current assignee: Silicon Fire AG
Priority date: 2008-12-18
Filing date: 2009-08-13
Publication date: 2011-09-28
Also published as: US20120010305A1; EP2647596A2; CA2747097C; DE202009019105U1; WO2010069622A1; CA2747097A1; EP2647596A3; US9631287B2

Abstract

The invention relates to methods and to plants (100) for supplying storable and transportable carbon-based energy carriers (108) using carbon dioxide (101) as the carbon supplier and using electricity (E1, E2). The plant (100) comprises a plant (300, 301; 400) for generating a first energy component in the form of DC power (E1) from renewable energy sources. Furthermore, a power supply plant (501) is provided for connecting the plant (100) to a grid (500), wherein the power supply plant (501) generates a second energy component in the form of DC power (E2) from the AC voltage of the grid (500). A device (102, 105) is designed for supplying hydrogen (103), wherein a portion of the power demand by said device (102, 105) is covered by the first energy component and another portion is covered by the second energy component. A carbon dioxide feed serves to introduce carbon dioxide (101) and a reaction area (106) is provided for producing a hydrocarbon, preferably methanol (108).

Description

Silicon Fire AG, Switzerland

S43-0028P-WO PCT

Method and system for providing an energy carrier using carbon dioxide as a carbon source and of electrical energy

The present application relates to methods and systems for providing storable and transportable carbon-based energy sources using carbon dioxide as a carbon source and using electrical energy.

[0002] The priorities of the following applications are claimed:

- International Patent Application PCT / EP2008 / 067895 filed on 18 December 2008;

- Provisional European Patent Application EP 09 154 271.2

- with filing date 4 March 2009.

Carbon dioxide CO ₂ (usually called carbon dioxide) is a chemical compound of carbon and oxygen. Carbon dioxide is a colorless and odorless gas. It is a natural constituent of the air at a low concentration and occurs in living things during cellular respiration, but also in the combustion of carbonaceous substances with sufficient presence of oxygen. Since the beginning of industrialization, the proportion of CO ₂ in the atmosphere has increased significantly. The main reason for this is man-made - the so-called anthropogenic - CO ₂ emissions. The carbon dioxide in the atmosphere absorbs part of the heat radiation. This property makes carbon dioxide a so-called greenhouse gas (GHG) and is one of the contributors to the global greenhouse effect.

For these and other reasons is currently being researched and developed in various directions to find a way to reduce the anthropogenic CO ₂ emissions. Particularly in the context of energy production, which is often due to the burning of fossil fuels, such as coal, oil or gas, but also with other combustion processes, such as waste incineration, there is a great need for CO ₂ reduction. More than 20 billion tons of CO ₂ are released into the atmosphere through such processes every year.

Among other things, the principle of climate neutrality is sought by pursuing approaches that attempt to compensate for energy production with CO ₂ emissions through alternative energy sources. This approach is shown in highly schematic form in FIG. Greenhouse gas (GHG) issuers, such as industrial companies (eg car manufacturers) 1 or power plant operators 2, invest or operate, for example, wind farms 3 at other locations as part of balancing projects in order to generate energy without GHG emissions. In purely mathematical terms, this can result in climate neutrality. Numerous companies are trying to buy a "climate-neutral" vest in this way.

Wind and solar power plants that convert renewable energy into electrical energy, have a transient power output, which greatly complicates a plant operation according to the requirements of an electrical grid and investment and operating costs for additional reserve and frequency control systems requires. As a result, the power generation costs of wind farms or solar power plants are substantially increased in comparison to power plants which can directly follow the power requirements of the interconnected grid.

[0007] It is considered a problem that currently almost all regenerative electrical energy that is generated in the public AC voltage Is fed in a network whose frequency may fluctuate only within very narrow limits (eg +/- 0.4%). This can only be achieved if power generation in the grid is always practically equal to consumption. The necessity of always having sufficient reserve and frequency control capacities for wind and solar power plants leads to a corresponding increase in the price of electricity generation from these plants. Wind and solar power plants in the electrical grid thus entail further "hidden" costs and problems.

LO [0008] Already in the present state of development of wind power plants in many countries, the electric power grid can be faced with serious problems when e.g. due to lack of wind or strong wind, the wind power is largely lost, especially if this failure occurs suddenly and unexpectedly. In any case, but the installed wind and

.5 solar power adjusted reserve and frequency control capacities necessary.

It follows that solar and wind power plants that feed into an electrical grid, can hardly replace the installed capacity of other power plants in the interconnected network. As a result, solar and wind power can only be valued in 10 with the saved fuel costs of the other thermal power plants available on the grid.

It is now the task of providing a method that is able to produce storable hydrocarbon-based energy sources, for example '.5 as fuels or fuels. The provision of these fuels should be carried out with as little additional CO ₂ as possible, and the use of these fuels should help to reduce CO ₂ emissions.

[00011] According to the invention, a method and a plant

(Device) provided for the provision of storable and transportable energy carrier.

According to a first embodiment of the invention, carbon dioxide! 5 is used as a carbon source. Preferably, the carbon dioxide is released taken from a combustion process or an oxidation process of carbon by means of CO ₂ separation. It is provided electric DC power. The DC power is largely generated by renewable energy, and it is used to conduct electrolysis to produce 5 hydrogen as an intermediate. The carbon dioxide is then reacted with the hydrogen to convert these products to methanol or other hydrocarbon.

In another preferred embodiment, a LO transformation of siliceous starting material takes place in a reduction process to silicon, wherein the energy for this reduction process is largely provided by renewable energies. Part of the reaction products of this reduction process is then used in the process for methanol production, in which process for L5 methanol production synthesis gas of carbon dioxide and hydrogen is used, as mentioned. The conversion of silicon dioxide-containing starting material to silicon can be carried out as a supplementary process step to the claimed process or combine with it.

According to the invention, as constant and long-term as possible plant operation of a corresponding Silicon-Fire plant is sought, which is achieved by supplementing the regenerative power supply with a conventional (for example fossil) power supply from a composite network. Preferably, the conventional power supply according to the invention becomes particular

> 5 switched during the low load periods of the electrical grid. That is, e.g. a wind and / or solar power plant and the inventive silicon-fire system with the existing electrical grid are combined economically and ecologically optimal, so that

- The total yield of the reaction products is maximally possible; so - and / or the CO ₂ emission is minimized as possible;

- and / or as constant and long-term plant utilization is achieved;

- and / or the product-specific investment and operating costs of the regenerative power plant and the Silicon-Fire plant as minimal as possible

5! The electrical energy from wind and / or solar power plants is not fed according to the invention in a network, but directly in a Silicon-Fire plant in storage and transportable forms of energy 5 (preferably converted into hydrocarbons such as methanol). This means that renewable energies are converted chemically into storage and transportable forms of energy.

It is a further advantage of transferring to storage and LO transportable forms of energy that the energy conversion efficiency is increased since photovoltaic systems do not require inverters to generate AC voltage and generally do not require lossy remote transport of electrical energy over longer power lines. L5

The generation costs of renewable electrical energy from solar and wind power plants are relatively high for the foreseeable future. This leads to the fact that, even with direct use of this electrical energy for chemical processes, as proposed here, the chemical products produced by it alone are .0 compared to the conventional - usually fossil - produced

Products are more expensive. This is especially true when the real environmental damage, e.g. a fossil power plant does not cause internalization, i. e. be taken into account in the overall balance.

In order to reduce this disadvantage, in the case of the silicon-fire system according to the invention, it is preferable to realize a combination of regenerative and conventional power supply that is as economically and ecologically as possible in networking with an existing electrical interconnected network. The Silicon-Fire plant concept therefore sees in a preferred embodiment

30 prior to use regenerative electrical energy largely directly according to their attack and electrical energy from an electrical grid, especially at its low load times for chemical reactions and thus to save. In times of peak electrical demand in the electrical grid, the regenerative energy - in order to achieve higher revenues - in the

35 interconnected network can be fed. This feed is optional. Preferably, instead of feeding the transiently occurring renewable electrical energy from wind and / or solar power plants in an electrical grid and balance their fluctuations and failures by other power plants or storage facilities and correct, with the electrical energy of the wind or solar power plants a chemical Silicon-Fire plant operated to produce storage and transportable forms of energy. If a corresponding Silicon-Fire plant is linked to a grid in order to receive a portion of the electrical energy from the interconnected grid, then by means of intelligent plant control or control, a currently available surplus share of energy can be obtained from the interconnected grid, while the remaining energy required is obtained from the plant-related solar and / or wind turbine. Here, therefore, there is an intelligent reversal of the previous principle, in which the fluctuations in the regenerative power generation of wind and / or solar power plants must be intercepted by connecting conventional power plants and / or storage facilities. Therefore, it is not necessary to maintain control and power reserves in the electrical grid for operating a Silicon-Fire system. This principle leads to significant cost reductions and allows the operator of a Silicon-Fire system to include additional technical and economic parameters in the control of the system.

In addition, control and regulation of the system power supply are much easier and more reliable, since the

Decision-making authority is the responsibility of the operator of the Silicon-Fire plant. In a conventional grid, which draws electricity from renewable and conventional plants, many partners are involved, which makes the control and logic linking of the plants and making decisions very complex, which in the recent past, for example, has led to loss of supply.

The production of the storage and transportable form of energy can be shut down at any time or even interrupted. this happens preferably when there is a peak energy demand in the electrical grid. The "chemical part" of the Silicon-Fire system can be shut down or switched off relatively quickly and easily, and the decision-making authority is also the responsibility of the operator of the Silicon-Fire system.

As an additional energy buffer, the energy form can be used, which is provided with the Silicon-Fire system. For example, methanol can be stored in order to be able to provide additional electrical energy in the event of peak energy demand in the electrical grid. For example, methanol may be burned in thermal power plants as needed, or electric power may be generated in fuel cells (for example, direct methanol fuel cells, MFC).

The present invention is based on the production of hydrogen by means of electrical energy as far as possible from wind and / or solar power plants in combination with the direct conversion of the hydrogen to a hydrocarbon. Hydrogen is therefore not stored or highly compressed or cooled and transported over longer distances, but serves as an intermediate, which is implemented at the site of its production. According to the invention, an energy conversion process in which solar or wind energy is converted into electrical energy is followed by material-converting (chemical) processes, namely the intermediary provision of hydrogen and the conversion of the hydrogen together with carbon dioxide to a hydrocarbon (e.g., methanol).

Taking into account appropriate energy technology, plant technology and economic requirements, together with the demand for careful use of all material, energy and economic resources, a new energy-related solution is provided according to the invention.

Further advantageous embodiments are given in the description, the figures and the dependent claims. In the drawings, various aspects of the invention are shown schematically, wherein the drawings show:

Fig. 1: a diagram illustrating the principle of climate neutrality by investing in or operating compensation projects;

2 is a diagram showing the basic steps of a first method according to the invention, or a corresponding one

Silicon-Fire plant, shows;

3 is a diagram showing the basic steps of a second method according to the invention, or a corresponding method

Silicon-Fire plant, shows; 4 is a diagram showing the basic steps of a further method according to the invention, or a corresponding method

Silicon-Fire plant, shows; Fig. 5 is a diagram showing the steps of another invention

Sub-procedure shows; Fig. 6 is a diagram showing the steps of another invention

Sub-procedure shows.

The inventive method is based on a novel concept which provides so-called reaction products using existing starting materials, which can be used either directly as an energy source, or indirectly, i. E. after carrying out further intermediate steps, can be used as energy sources.

The term energy source is used here for substances that can be used either directly as fuel or fuel (such as methanol 108), and also for substances (such as silicon 603) that have an energy content or an increased energy level and the in further steps with the release of energy (see energy E3 in FIG. 6) and / or with delivery of a further energy carrier (such as hydrogen 103) can be implemented.

The transportability of the energy carrier is characterized here by the chemical reaction potential. In the case of hydrocarbons (such as methanol 108) as an energy source certain conditions should be observed during storage and transport, which are similar to the conditions for the handling of fossil fuels. Here you can easily use the existing infrastructure. Only on the material side can certain adjustments be required.

In the case of silicon 603 as an energy carrier certain conditions should be observed during storage and during transport, in order not to trigger any unwanted or uncontrolled reaction (oxidation) of the silicon. The silicon 603 should preferably be stored and transported dry. In addition, the silicon 603 should not be heated, otherwise the likelihood of reaction with water vapor from the ambient air or with oxygen increases. Studies have shown that silicon has up to about 300 degrees Celsius only a very low tendency to react with water or oxygen. Ideally, storing and transporting the silicon 603 together with a water getter (i.e., a substance that is hydrophilic) and / or an oxygen getter (i.e., a substance that is oxygen-attracting) is desirable.

The term silicon dioxide-containing starting material 601 is used here for substances which contain a large proportion of silicon dioxide (SiO ₂ ). Particularly suitable are sand and shale (SiO ₂ + [CO ₃ ] ² ). Sand is a .5 naturally occurring, unconsolidated sedimentary rock and occurs in greater or lesser concentrations throughout the earth's surface. Much of the sand is quartz (silicon dioxide, SiO ₂ ).

According to a first embodiment of the invention, carbon dioxide 30 is used 101 as a carbon source, as indicated schematically in Fig. 2.

Preferably, the carbon dioxide 101 is taken from a combustion process 201 (symbolized by a fire in FIG. 3) or an oxidation process via CO ₂ separation (eg, a Silicon-Fire flue gas purification plant 203). Furthermore, DC electric power El is provided. The 35 DC energy El is largely regenerative (eg by one of the plants 300 or 400 in FIG. 4). The DC power El is used to perform electrolysis to produce hydrogen 103 as an intermediate. The electrolysis plant, respectively, carrying out such an electrolysis, is indicated in FIG. 2 by the reference numeral 105 5. The carbon dioxide 101 is then reacted (for example by a methanol synthesis) with the hydrogen 103 to convert the (intermediates 101, 103 to methanol 108 or to another hydrocarbon The reaction can be carried out in a reaction vessel 106 and the removal, respectively the provision of the methanol is indicated in FIG. LO 2 by the reference numeral 107.

In the following, further basic details of this method and the corresponding Silicon-Fire system 100 will be described.

L5 [00035] In order to be able to generate hydrogen 103 as an intermediate, water electrolysis using DC El is suitable. The required hydrogen 103 is produced in an electrolysis plant 105 by the electrolysis of water H ₂ O:

10 H ₂ O - 286.02 kJ = H ₂ + 0.5 O ₂ . (Reaction 1)

The required (electrical) energy El for this reaction of 286.02 kJ / mol corresponds to 143000 kJ per kg of H ₂ .

The synthesis of methanol 108 (CH ₃ OH) proceeds in the Silicon-Fire plant 100 after the exothermic reaction between carbon dioxide 101 (CO ₂ ) and hydrogen 103 (H ₂ ), as follows:

CO ₂ + 3 H ₂ = CH ₃ OH + H ₂ O - 49.6 kJ (methanol gaseous). (Reaction 2) iθ

The resulting heat of reaction Wl of 49.6 kJ / mol = 1550 kJ per kg of methanol = 0.43 kWh per kg of methanol is removed from the corresponding synthesis reactor 106. Typical synthesis conditions in the synthesis reactor 106 are about 50 bar and about 270 ⁰ C, so that the

: 5 reaction heat Wl can also be used, for example for a nearby desalination plant or heating system.

Preferably, the methanol synthesis is carried out using catalysts to keep reaction temperature and pressure and 5 reaction time low and to ensure that high quality (pure) methanol 108 is formed as the reaction product.

In another preferred embodiment of the invention, a methanol synthesis according to a propagated by Prof. George A. Olah

LO electrolysis process carried out. Details can be found, for example, in the book "Beyond Oil and Gas: The Methanol Economy", George A. Olah et al., Wiley-VCH, 1998, ISBN 0-471-14877-6, Chapter 11, page 196. Other Details can also be found in US patent application US 2009/0014336 A1, which is described by Prof. George A. Olah by the electrolysis of CO ₂ by methanol synthesis

.5 and H ₂ O as follows:

CO ₂ + 2 H ₂ O - 682.01 kJ = CH ₃ OH + 1.5 O ₂ (Reaction 3)

In this reaction, in an intermediate step CO and H ₂ in O form a ratio of approximately 1: 2. The CO and H ₂ produced at a cathode can be converted to methanol with a copper or nickel based catalyst. The synthesis route after reaction 3 is connected to a theoretical feed of 682.01 kJ = 0.189 kWh of electrical energy per mole of methanol 108 produced. : 5

If the Silicon-Fire plant 100 is located in the vicinity of a CO ₂ source, can be dispensed with a liquefaction for the transport and the transport itself of CO ₂ . Otherwise, it is relatively easy in the prior art to liquefy the CO ₂ and bring it to a Silicon-Fire plant 100. In the absence of liquefaction, storage and transport over longer distances, the CO _{2 is} expected to be cost-neutral, taking CO ₂ avoidance credits into account. Even in the case of transport, the costs of "acquiring" CO _{2 are} relatively low.

FIG. 3 shows further steps of a first invention Process, respectively a part of a Silicon-Fire plant 200 shown. Preferably, as already mentioned, the carbon dioxide 101 from a combustion process 201 (symbolized here by a fire) or an oxidation process by means of CO ₂ capture, eg with a Silicon-Fire flue gas cleaning system 203 taken. The Silicon Fire

Flue gas purification system 203 can be constructed, for example, according to the principle of flue gas scrubbing, wherein the CO ₂ is "washed out" by flue gas 202. A flue gas scrubbing system which uses NaOH as scrubbing solution and in which the NaOH is recycled is particularly suitable are for example the parallel application EP 1 958 683, which was filed on 7 August 2007. However, other principles of CO ₂ capture or recovery can be used.

The silicone-fire flue gas cleaning system 203 makes it possible to remove CO ₂ (referred to herein as recyclable material) from the flue gas 202. This CO ₂ is then fed directly or indirectly to the Silicon-Fire plant 100, which then generates / synthesizes a hydrocarbon (preferably methanol 108) using CO ₂ as the carbon source and using electrical energy.

4 shows, in a schematic block diagram, the most important building blocks / components or method steps of a silicon-fire installation 100. This installation 100 is designed such that a method for providing storable and transportable energy sources 108 can be carried out. The corresponding procedure is based on the following basic steps.

Carbon dioxide 101 is provided as a carbon source, as previously described. The required DC electric energy El is generated here as far as possible by means of renewable energy technology and made available to the Silicon-Fire plant 100. Particularly suitable as renewable energy technology are solar thermal systems 300 and photovoltaic systems 400, which are based on solar modules. It is also possible to provide a combination of both system types 300 and 400, since the area requirement, based on the electrical power, of the solar thermal system 300 is smaller than that of a Photovoltaic system 400.

It is carried out according to the invention, an electrolysis 105 using the DC electrical energy El to produce hydrogen 103, or hydrogen ions, as an intermediate. The electrolysis 105 can be carried out according to the following three different approaches:

Either it is a direct water electrolysis according to reaction 1, as shown in FIG. 4, or silicon is produced by electrolytic means from a silicon dioxide-containing compound, which then in a subsequent hydrolysis reaction with water 102 to form hydrogen 103 and silicon dioxide responding

- Or it is directly produced by electrolytic route methanol 108 (see Reaction 3), which also intermediates hydrogen, respectively hydrogen ions occur, but directly with the other ions or

Reactant react to methanol 108.

In the processes which do not directly generate methanol 108 by electrolytic means, finally, in the plant 100, hydrogen 103 and carbon dioxide 101 are combined to convert them in a reaction 106 to methanol 108, or to another hydrocarbon. The methanol 108 can then be removed from the system 100 as shown by the arrow 107.

In Fig. 4, a particularly preferred system 100 is shown, which is constructed so that it reduces or compensates for the aforementioned disadvantages. For this reason, preferably an economically and ecologically optimal combination of regenerative power supply (by the systems 300 and / or 400) and conventional power supply, here by a part of a

Connected network 500 shown realized. The silicone fire system 100 therefore provides in a preferred embodiment, the regenerative electric energy El largely directly according to their attack for chemical reactions (here the electrolysis reaction 105) to use and thus also to save. Another portion of the required energy is obtained from the interconnected network 500. This Proportion is converted into direct current (energy) E2. For this purpose, a corresponding converter 501 is used, as indicated in Fig. 4 in a schematic form. The corresponding system components or components are also referred to here as power supply system 501. 5

By means of an intelligent system controller 110, the power supply of the system 100 is controlled and regulated. In principle, the respective currently available excess energy portion E2 is taken from the interconnected network 500, while the other energy portion (here El) so far

LO is possible from a plant-related solar power plant 300 and / or 400 (or is derived from a wind power plant.) So here comes to an intelligent reversal of the previous principle, in which the energy fluctuations of renewable energy systems 300, 400 are intercepted by switching on and off conventional systems It is therefore necessary to

L5 Operate a Silicon-Fire plant 100 no additional power and frequency control capacity for the renewable power plants in the interconnected network 500 vorzuhalten. This principle allows the operator of a Silicon-Fire plant 100 to include additional technical and economic parameters in the control of the plant 100. These parameters are

.0 are so-called input quantities II, 12, etc., which are included by the controller 110 in decisions. A part of the parameters can be specified within the controller 110 in a parameter memory 111. Another part of the parameters can come from the outside. Here, for example, price and / or availability information from the operator of the interconnected network 500

15 go.

In the system controller 110, so-called software-based decision processes are implemented. A processor of the controller 110 executes control software and makes decisions taking into account parameters 30. These decisions are implemented in switching or

Control commands that cause, for example, via control or signal lines 112, 113, 114, the control / regulation of energy and mass flows.

Viewed from the side of the interconnected network, 35 of the Silicon-Fire system 100 is a consumer who is rapidly adding and can be switched off and is relatively flexible. If, for example, there is a sudden increase in the demand for electrical energy on the network side, then the controller 110 can shut down or completely switch off the proportion E2. In this case, either from this moment correspondingly less hydrogen 5 103 is produced, if energy El is available, or the electrolysis is temporarily stopped altogether.

In Fig. 4 is indicated by dashed arrows 112, which emanate from the controller 110 that the controller 110, the energy flows El and

LO E2 regulates. The arrows 112 represent control or signal lines. Other possible control or signal lines 113, 114 are also shown. The control or signal line 113 controls, for example, the amount of CO ₂ available for the reaction 106. For example, if less hydrogen 103 is produced because there is no energy E2 available then less CO ₂ will be required

L5 are supplied. The optional control or signal line 114 may regulate, for example, the amount of H ₂ . Such a regulation is useful, for example, if there is a hydrogen buffer, which can be taken from hydrogen 103, even if at the moment no hydrogen or less hydrogen is produced by electrolysis 105.

O

Investigations have shown that it makes particularly economic and environmental sense if the Silicon-Fire plant 100 between 15 and 50% of the electrical energy demand solar and the remaining energy needs from the interconnected network 500 (i.e., mainly fossil) relates. Most notably

5, it is preferable to cover between 30 and 40% of the electrical energy requirement solar and the remaining 70 to 60% from the interconnected network 500 (i.e., mainly fossil). The intelligent system controller 110 is set or programmed according to these specifications.

Particularly preferred is an embodiment of the system 100, which provides for the procurement of low-cost electrical energy in the low-load periods from the interconnected network 500.

According to a preferred embodiment of the invention, the system control 110 is set or programmed such that the networking between regenerative electrical energy source 300 and / or 400 and interconnected electrical network 500 is optimized in such a way that the maximum cost of the electrical energy is minimized with maximum utilization of the regenerative electrical energy source 300 and / or 400.

According to a preferred embodiment of the invention, the plant controller 110 is set or programmed so that the networking between regenerative electrical energy source 300 and / or 400 and electrical interconnected network 500 is optimized so that the maximum utilization of the regenerative electrical energy source 300 and / or 400 and taking into account the total cost of electrical energy and the load or operating times of the entire system 100 and their equipment parts, the total cost of the hydrocarbon product 108 will be minimal.

According to a preferred embodiment of the invention, the plant controller 110 is set or programmed so that the networking between regenerative electrical energy source 300 and / or 400 and electrical interconnected network 500 is optimized in that by temporarily feeding the regenerative energy source 300 and / or 400 In the interconnected electric network 500 at its peak times proceeds are achieved and thereby the total cost of electrical energy for the inventive method or the total cost of the hydrocarbon product 108 are reduced and minimized as possible.

In times of peak electrical demand of the electrical grid 500, the regenerative energy El - to achieve higher revenues - are also fed into the grid.

The aspects of these preferred embodiments can be easily combined by a corresponding design of the controller 110.

In the following, further basic aspects of a method according to the invention for providing storable and transportable energy carriers are shown. In this process, silicon 603, as a first storable and transportable energy source, and methanol 108, as a second storable and transportable energy source. The method comprises at least the following steps.

5 Through a transformation becomes sihzdioxidhaltiges

Ausgangsmateπal 601 converted by means of a reduction process 602 in elemental silicon 603, as shown in Fig. 5. The elemental silicon 603 is referred to here for simplicity as silicon. The required electrical (Pπmar) Energιe El for this reduction process 602 is provided according to LO invention from a renewable energy source 300. In a downstream step, at least a portion of the silicon 603 may be employed in a methanol production process. In this process, methanol production occurs e.g. Synthesis gas from carbon dioxide 101 and hydrogen 103 is used. The silicon 603 can also be used as an energy carrier from the process

5 are removed. The silicon 603 may be stored or removed, for example.

[00063] The transform 602 is preferably indicated schematically (with the participation of electric current El), ¹ O as in Fig. 5, an electrochemical electrolytic transformation.

In the electrochemical transformation 602 of Fig. 5, the (Pπmar) energy El is supplied for transformation by current generated from sunlight. For the electrochemical transformation 602, a ^• 5 solar system 300 is used, as indicated in Fig. 5 schematically.

For example, the electrochemical transformation 602 may be performed by using silicon dioxide as an electrode. As the second electrode, a metal is used. The electrolyte is used, for example

0 calcium chloride (CaCl ₂ ). This electrochemical transformation process 602 works particularly well with a porous silicon dioxide electrode, which may be sintered, for example, of silicon dioxide. Details of this procedure can be found in the following publications: - Nature mateπals 2003 Jun; 2 (6): 397-401, Nohira T, Yasuda K, Ito Y,

5 Pubiisher Nature Pub. Group. - "New Silicon Production Method with No Carbon Reductant", George Zheng Chen; DJ. Fray, TW Farthing, Tom W. (2000).

"Direct Electrochemical Reduction of Titanium Dioxide to Titanium in Molten Calcium Chlorides", George Zheng Chen, DJ Fray, T.W. Farthing, Nature 407

5 (6802): 361-364. doi: 10.1038 / 35030069

Silicon dioxide in molten CaCl ₂ , YASUDA Kouji - Effect of electrolysis potential on reduction of solid silicon dioxide; NOHIRA Toshiyuki; ITO Yasuhiko; The Journal of Physics and Chemistry of Solids, ISSN 0022-3697, International IUPAC Conference on High Temperature Materials Chemistry no. 11, Tokyo, JAPON (19/05/2003),

LO 2005, vol. 66, no 2-4 (491 p.);

- US 6540902 Bl;

- WO 2006092615 Al.

[00066] A reduction method is preferably carried out at a temperature of approximately 1900 K .5 (= 1630 ⁰ C) 602 to reduce the silica to silicon 601 603rd By contrast, significantly lower temperatures (preferably less than 500 ^° C.) are required for the electrochemical transformation 602.

In connection with FIGS. 6 and 7 it is described how silicon 603 can be used as an energy source. The reduced silicon 603 is a high energy substance. This silicon has the tendency to reoxidize with water in liquid or vapor form to silica 604 (reverse reaction), as shown schematically in FIG. In the so-called

Hydrogen 605 of silicon 603 releases energy E3 (e.g., heat energy) because it is an exothermic reaction. In addition to the silicon dioxide 604, hydrogen 1038 is produced, which can be used, for example, as an energy carrier for the production of methanol 108. Preferably, hydrolysis 605 occurs at elevated temperatures. Preference is given to temperatures which are marked

0 are above 100 ⁰ C. In the temperature range between 100 and 300 ⁰ C, a conversion in useful amounts is achieved when the silicon 603 is brought in very fine-grained or powdery consistency with water vapor 102 in connection and durchmengt. Since silicon 603 up to about 300 ⁰ C otherwise has only a very low tendency to react with water is

5 preferably hydrolysis 605 at temperatures in the temperature range carried out between 300 and 600 ⁰ C.

The hydrolysis can also be carried out with aqueous hydroxide and alkali carbonate solutions, for which preferably temperatures between 60 and 150 ⁰ C come into question.

According to the invention, in a process according to FIG. 6, the silicon 603 is introduced into a reaction zone and mixed with water 102 in liquid or vaporous form. In addition, according to the invention, care is taken

LO that the silicon 603 has a minimum temperature. Either the silicon 603 is heated for this purpose (e.g., with heating means, or by heat-generating or heat-emitting additives), or the silicon 603 is already at a corresponding temperature level upon introduction.

.5

Under these conditions, hydrogen 103 is then released as gas in the reaction area. The hydrogen 103 is removed from the reaction area.

The following is a numerical example of a method according to FIG. 6 or that according to FIG. 5 in combination with FIG. 6:

1 mole (= 60.1 g) of SiO ₂ forms 1 mole (= 28 g) of Si. 1 mole (= 28 g) of Si again forms 1 mole (= 451 g) of H ₂ . This means that 2.15 kg of SiO ₂ form 1 kg of Si, and from this 1 kg of Si 5, 1.6 m ^{3 of} H _{2 are} formed.

The methanol production can be carried out according to one of the known and industrially used methods. Preference is given to a process in which a catalyst (for example a CuO-ZnO-Cr ₂ O ₃ or a Cu-Zn-0 Al ₂ O ₃ catalyst) is used.

The invention has the advantage that in the reduction of the silicon dioxide and in the reduction of the water 102 no CO _{2 is} released, as long as for these reactions only energy El is used, which comes from a plant 300 and / or 400. The required energy is therefore at least partly from renewable energy sources, preferably from Annexes 300 and / or 400.

The elemental silicon 603 is preferably used in powder form, or in granular or granular form in the hydrolysis 605.

According to the invention, CO ₂ 101 serves as a starting material and carbon source for the synthesis of methanol in the reactor 106. The CO ₂ source used are preferably: steam reforming plants, natural gas CO ₂ - deposition plants, cement factories, bioethanol plants,

Seawater desalination plants, power plants and other plants or combustion processes 201 that emit large quantities of CO ₂ .

The invention makes it possible to avoid the considerable economic disadvantages of known approaches, if - as in the case of the Silicon-Fire plant 100 - the transiently accumulating electrical solar and / or wind energy is converted directly into chemical reaction enthalpy and stored chemically bound, without the need for additional capacities for reserve power and / or frequency regulation in the interconnected grid and the associated expenses.

In photovoltaic power generation by means of a photovoltaic system 400, a further advantage is that the direct current from the solar cells of the photovoltaic system 400 DC direct current El can be used directly for the chemical process (electrolysis 105) without being converted by converters into alternating current for voltage transformation have to. Reference numerals:

Automotive / Automotive 1

Power plant operator 2

Wind Farm 3

Silicon-Fire plant 100

Carbon dioxide 101

Water 102

Hydrogen 103

Providing carbon dioxide 104

Performing an electrolysis 105

Merging the hydrogen 106

(H ₂ ) and the carbon dioxide /

synthesis reactor

Discharge / Provide Methanol 107 Transportable Energy Carriers 108

(Plant) control 110

Parameter memory 111

Control or signal lines 112, 113, 114

Silicon-Fire unit 200

Combustion process 201

Flue gas with CO ₂ 202

Silicon-Fire flue gas scrubbing 203

Clean gas 204

CO ₂ -free chimney 205

Removal of CO ₂ 206

Solar thermal plant 300

Conversion of heat into 301

direct current

Solar system (photovoltaic system) 400

Interconnected network 500

Conversion of AC voltage to 501

direct current

(Power plant) Silica-containing 601

starting material

Silicon 603

Reduction Procedure 602

Silica as 604

Back reaction product

Hydrolysis 605

DC power El

Additional electrical energy E2

Energy E3

Input quantities II, 12, etc.

Primary energy Pl, P2

Reaction (off) heat of the Wl methanol synthesis

Claims

claims:

A method of providing storable and transportable energy carriers (108) comprising the steps of:

Providing (104) carbon dioxide (CO ₂ , 101) as a carbon source,

- Providing electric DC power (El) generated by renewable energy technology (300, 400), providing additional electrical energy (E2) coming from a fossil

Fuel-powered power plant or from an electrical grid (500) comes, whose / momentarily low utilization makes it possible to provide the additional electrical energy (E2).

Performing electrolysis (105) using said DC electrical energy (El) and said additional electrical energy (E2) to produce hydrogen (H ₂ ; 103) as an intermediate,

- combining (106) the hydrogen (H ₂ , 103) and the carbon dioxide (CO ₂ , 101) to convert it to methanol (108).

2. The method according to claim 1, characterized in that the removal of carbon dioxide (CO ₂ ; 101) from a combustion process (201) or an oxidation process by means of CO ₂ separation (203).

3. The method according to claim 1 or 2, characterized in that during the electrolysis silicon dioxide-containing starting material (601) is reduced to silicon (603).

4. The method according to claim 3, characterized in that hydrogen (H ₂ , 103) is provided by silicon (603) with water (H ₂ O, 102) to the reaction (605) is brought.

5. Process according to claim 1 or 2, characterized in that the electrolysis is a water electrolysis (105) in which hydrogen (H ₂ , 103) is produced directly from water (H ₂ O; 102).

6. The method according to any one of the preceding claims, characterized in that the direct current energy (El) is supplied by sunlight by means of a solar thermal system (400) and / or a photovoltaic system (300).

7. The method according to any one of the preceding claims, characterized in that the silicon (603) is provided as a storable and transportable energy carrier and that from the carbon dioxide (101) and hydrogen (103) in the process (106) for methanol production methanol (108 ) is provided as another storable and transportable energy carrier.

8. The method according to any one of the preceding claims 1 to 6, characterized in that silicon (603) is provided as a storable and transportable energy carrier, wherein in another

Step (605), contacting water or water vapor with the silicon (603) to provide, in a hydrolysis reaction (605), hydrogen (103), silica (604), and an amount of energy (E3).

9. A plant (100) for providing a storable and transportable energy carrier (108), comprising a plant (300, 301, 400) for generating a first portion of energy in the form of direct current energy (El) from renewable energy sources, a power supply system (501) for connection the system (100) to a network (500), wherein the power supply system (501) from AC voltage of the interconnected network (500) generates a second portion of energy in the form of direct current energy (E2), a device (102, 105) for providing hydrogen (103 ) as an intermediate, wherein a part of the energy demand of this device (102, 105) by the first part of energy and another

Part is covered by the second part of the energy, a carbon dioxide supply for introducing carbon dioxide (101), a reaction region for producing a hydrocarbon, preferably methanol (108), wherein in the reaction region of the hydrogen (103) with the carbon dioxide (101) comes to reaction . a withdrawal (107) for the hydrocarbon.

A plant (100) according to claim 9, characterized in that it comprises a controller (110) adapted to control the ratio between the first energy fraction and the second energy fraction.

11. Plant (100) according to claim 10, characterized in that _/

Control (110) controls the feeding of the second part of energy from the interconnected network (500), wherein in a software-based decision process parameters (II, 12, etc.) are taken into account by the controller (110), the information about the availability of electrical energy of the interconnected network (500) and / or via economic parameters.

12. Plant (100) according to claim 10 or 11, characterized in that in the controller (110) a software-based decision-making process is implemented, so that between 15 and 50% of the electrical energy demand by the first part of energy and the remaining energy demand from the interconnected network (500) is covered.

13. Plant (100) according to claim 10 or 11, characterized in that in the controller (110) a software-based decision-making process is implemented, so that between 30 and 40% of the electrical energy demand by the first part of energy and the remaining 70 to 60% be covered by the interconnected network (500).

14. Plant (100) according to one of claims 10 to 11, characterized in that with the controller (110) via control or signal lines (112, 113, 114) energy and / or mass flows in the system (100) and regulated / or controlled.