U.S. patent application number 14/428280 was filed with the patent office on 2015-11-19 for method for storing discontinuously produced energy.
The applicant listed for this patent is VOESTALPINE STAHL GMBH. Invention is credited to Thomas Burgler, Wolfgang Eder, Peter Schwab.
Application Number | 20150329931 14/428280 |
Document ID | / |
Family ID | 50277660 |
Filed Date | 2015-11-19 |
United States Patent
Application |
20150329931 |
Kind Code |
A1 |
Eder; Wolfgang ; et
al. |
November 19, 2015 |
METHOD FOR STORING DISCONTINUOUSLY PRODUCED ENERGY
Abstract
A method for temporarily storing energy in which iron ore is
reduced with hydrogen and the resulting intermediate product of
reduced iron ore and possibly accompanying substances is subjected
to further metallurgical processing; the hydrogen is produced
through electrolysis of water; the electrical energy required for
the electrolysis is regenerative energy from hydroelectric and/or
wind and/or photovoltaic sources or other regenerative forms of
energy and the hydrogen and/or the intermediate product is produced
regardless of the current demand, whenever enough regeneratively
produced electrical energy is available; and unneeded intermediate
product is stored until there is demand or it is used so that the
regenerative energy that is stored therein is also stored and a
method for storing discontinuously produced energy in which the
discontinuously produced energy, when it is present or after its
production, is conveyed into a process in which a storable
intermediate product is produced from a source material and the
storable intermediate product is stored until it is required and
retrieved for the production of an end product.
Inventors: |
Eder; Wolfgang; (Linz,
AT) ; Burgler; Thomas; (Steyregg, AT) ;
Schwab; Peter; (Linz, AT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VOESTALPINE STAHL GMBH |
Linz |
|
AT |
|
|
Family ID: |
50277660 |
Appl. No.: |
14/428280 |
Filed: |
September 10, 2013 |
PCT Filed: |
September 10, 2013 |
PCT NO: |
PCT/EP2013/068727 |
371 Date: |
August 4, 2015 |
Current U.S.
Class: |
75/10.43 ;
75/10.44; 75/505 |
Current CPC
Class: |
C25B 1/04 20130101; Y02E
70/10 20130101; Y02P 10/138 20151101; Y02P 10/128 20151101; C21B
13/004 20130101; Y02P 10/126 20151101; C01B 3/02 20130101; C21B
13/02 20130101; C21B 13/0073 20130101; Y02P 10/134 20151101; Y02P
20/133 20151101; Y02E 60/36 20130101; Y02P 10/122 20151101; Y02E
60/366 20130101; C21B 13/14 20130101; C22C 38/00 20130101; C22C
37/00 20130101; Y02P 10/136 20151101; C21B 13/0086 20130101 |
International
Class: |
C21B 13/14 20060101
C21B013/14; C25B 1/04 20060101 C25B001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2012 |
DE |
10 2012 108 631.1 |
Sep 28, 2012 |
DE |
10 2012 109 284.2 |
Apr 19, 2013 |
DE |
10 2013 104 002.0 |
Claims
1. A method, for storing discontinuously produced energy,
comprising: supplying the discontinuously produced energy, when it
is present or after it is produced, to a process in which a
storable intermediate product is produced from a source material;
storing the storable intermediate product until it is required; and
retrieved retrieving the storable intermediate product for the
production of an end product; wherein the intermediate product is a
ferrous material obtained from a direct reduction method; the
source material is iron ore, which is directly reduced with the aid
of hydrogen and/or carbon-containing or hydrogen-containing gas
flows, and the hydrogen is produced through electrolysis of water
using regeneratively produced electrical energy, and the hydrogen
for the reduction has at least enough carbon-containing or
hydrogen-containing gas added to it in various modifications to
make the carbon content in the intermediate product 0.0005 mass %
to 6.3 mass %.
2. The method according to claim 1, comprising producing as much
intermediate product as an existing discontinuously produced energy
quantity permits and storing the intermediate product regardless of
a demand for the intermediate product.
3. The method according to claim 1, wherein the intermediate
product is a product that is smelted or transformed using
electrical energy and/or is a product that is prepared from a raw
material or source material through mechanical processing using
electrical energy and/or is a product that is transformed by a gas
that has been produced using electrical energy.
4. (canceled)
5. The method according to claim 1, in which iron ore is reduced
with hydrogen and with carbon-containing or hydrogen-containing gas
flows and the resulting intermediate product of reduced iron ore
and possibly accompanying substances is subjected to further
metallurgical processing, comprising producing the hydrogen through
electrolysis of water wherein the electrical energy required for
the electrolysis is regenerative energy from hydroelectric and/or
wind and/or photovoltaic sources or other regenerative forms of
energy and the hydrogen and/or the intermediate product is produced
regardless of the current demand, whenever enough regeneratively
produced, electrical energy is available, where unneeded
intermediate product is stored until there is demand or it is used
so that the regenerative energy that is stored therein is also
stored.
6. The method according to claim 5, comprising, in the reduction of
the iron ore to produce the intermediate product, adding a
carbon-containing or hydrogen-containing gas to the hydrogen in
various modifications in order to be incorporated as carbon into
the intermediate product in the reduction process.
7. The method according to claim 1, wherein the carbon-containing
or hydrogen-containing gas is methane or other carbon-containing
gases from industrial processes or from biogas production or the
pyrolysis of renewable resources.
8. The method according to claim 1, wherein the hydrogen for the
reduction has at least enough carbon-containing or
hydrogen-containing gas added to it in various modifications to
make the carbon content in the intermediate product 1 mass % to 3
mass %.
9. The method according to claim 1, comprising introducing the
reduction gas composed of hydrogen and possibly a carbon-containing
or hydrogen-containing gas into the reduction process at a
temperature of 450.degree. C. to 1200.degree. C.
10. The method according to claim 1, wherein excess pressure in the
reduction is between 0 bar and 15 bar.
11. The method according to claim 1, wherein a ratio between
hydrogen from regenerative production and carbon-containing or
hydrogen-containing gas flows is varied continuously as a function
of availability; when there is sufficient regenerative energy,
hydrogen from the production with regenerative energy is used, and
in the absence of discontinuously produced regenerative energy, the
system switches to carbon-containing or hydrogen-containing gas
flows from continuously produced regenerative energy.
12. The method according to claim 1, comprising adjusting the
content of hydrogen and/or carbon-containing or hydrogen-containing
gas flows in the overall gas flow using a predictive control;
wherein the predictive control is used to measure the predicted
yield/production quantity of hydrogen and/or regenerative energy
and/or carbon-containing or hydrogen-containing gas flows from
biogas synthesis or from the gasification of renewable resources
and/or forecasts flow into the estimation of regenerative energy;
and demand predictions of other external consumers also flow into
the process, thus permitting the electrical energy from
regenerative sources to be distributed optimally and in the most
economical fashion.
13. The method according to claim 1, wherein almost the entire gas
flow that exits the direct reduction system is conveyed back into
the process.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a method for storing
discontinuously produced energy.
BACKGROUND OF THE INVENTION
[0002] The percentage of regenerative energy should be increased
globally; regenerative energy includes not only energy from
renewable resources, but also energy generated from hydroelectric
power, sunlight, and wind. Frequently, renewable resources can be
used to produce energy continuously, for example in biomass power
plants or biogas production plants.
[0003] When solar energy or wind energy is used, however, energy is
produced discontinuously due to its dependence on the weather. This
discontinuously produced energy is not always available when it is
actually needed, presenting the problem of storing this energy and
making it available when needed.
[0004] In particular, it is difficult to store this discontinuously
produced energy in a form that can be easily made immediately
available for the retail customer or for feeding into networks for
retail customers.
[0005] The object of the present invention is to create a method
for storing discontinuously produced energy.
SUMMARY OF THE INVENTION
[0006] According to the invention, the goal is not to use
discontinuously produced energy in its originally produced form,
but rather to use the energy for producing an easily storable
intermediate product and thus to incorporate the energy into this
intermediate product, with the intermediate product being a product
that is required all over the world. When discontinuous energy is
present, this intermediate product is produced and stored
regardless of the demand for the intermediate product and then is
supplied for further processing as needed. Since the production of
the intermediate product requires large quantities of energy
anyway, the energy consumption that would already occur in the
production would be shifted in terms of time and location.
[0007] According to the invention, metal, for example, in
particular steel, is produced as the end product. Basically, the
method according to the invention is suitable for all forms of
industrial production in which a storable intermediate product is
generated.
[0008] In this connection, it is advantageous that the storage of
the discontinuously produced energy in this case does not require a
feeding back from a storage reservoir--of whatever type--into the
original energy, but instead the original energy is used in a
practical way and stored in the intermediate product and additional
energy does not have to be expended in order to produce the
intermediate product at the production site of the end product.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention will be explained by way of example in
conjunction with the drawings. In the drawings:
[0010] FIG. 1 shows an overview of the method according to the
invention in an exemplary embodiment (electric arc furnace);
[0011] FIG. 2 shows an overview of the method according to the
invention in a second exemplary embodiment (LD process);
[0012] FIG. 3 schematically depicts the flows of materials and
energy.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] According to the invention, the intermediate product is an
intermediate product whose production requires an expenditure of
energy that is quite high, in particular intermediate products for
which a smelting process and/or a reduction process is required,
which is in particular carried out using electricity, e.g. by means
of an electric arc. In particular, however, this intermediate
product can also be composed of iron directly reduced primarily
from iron oxide carriers, e.g. in the form of a sponge iron or
so-called hot briquetted iron (HBI). The use of the discontinuously
produced regenerative energy and the storage thereof in the
intermediate product also has the advantage that it is possible to
operate in a climate neutral fashion.
[0014] Steel production is currently carried out in a variety of
ways. Classic steel production is carried out by producing pig iron
in the hot furnace process, primarily out of iron oxide carriers.
In this method, approx. 450 to 600 kg of reducing agent, usually
coke, is consumed per metric ton of pig iron; this method, both in
the production of coke from coal and in the production of the pig
iron, releases very significant quantities of CO.sub.2. In
addition, so-called "direct reduction methods" are known (methods
according to the brands MIDREX, FINMET, ENERGIRON/HYL, etc.), in
which the sponge iron is produced primarily from iron oxide
carriers in the form of HDRI (hot direct reduced iron), CDRI (cold
direct reduced iron), or so-called HBI (hot briquetted iron).
[0015] There are also so-called smelting reduction methods in which
the melting process, the production of reduction gas, and the
direct reduction are combined with one another, for example the
methods of the brands COREX, FINEX, HiSmelt, or HiSarna.
[0016] Sponge irons in the form of HDRI, CDRI, and HBI usually
undergo further processing in electric furnaces, which is
extraordinarily energy-intensive. The direct reduction is carried
out using hydrogen and carbon monoxide from methane and synthesis
gas if necessary. For example, in the so-called MIDREX method,
first methane is transformed according to the following
reaction:
CH.sub.4+CO.sub.2=2CO+2H.sub.2
[0017] and the iron oxide reacts with the reduction gas, for
example according to the following formula:
Fe.sub.2O.sub.3+6CO(H.sub.2)=2Fe+3CO.sub.2(H.sub.2O)+CO(H.sub.2).
[0018] This method also emits CO.sub.2.
[0019] DE 198 53 747 C1 has disclosed a combined process for the
direct reduction of fine ores in which the reduction is to be
carried out with hydrogen or another reduction gas in a horizontal
turbulence layer.
[0020] DE 197 14 512 A1 has disclosed a power station with solar
power generation, an electrolysis unit, and an industrial
metallurgical process; this industrial process relates either to
the power-intensive metal production of aluminum from bauxite or is
intended to be a metallurgical process with hydrogen as a reducing
agent in the production of nonferrous metals such as tungsten,
molybdenum, nickel, or the like or is intended to be a
metallurgical process with hydrogen as a reducing agent using the
direct reduction method in the production of ferrous metals. The
cited document, however, does not explain this in detail.
[0021] WO 2011/018124 has disclosed methods and systems for
producing storable and transportable carbon-based energy sources
using carbon dioxide and using regenerative electrical energy and
fossil fuels. In this case, a percentage of regeneratively produced
methanol is prepared together with a percentage of methanol that is
produced by means of non-regenerative electrical energy and/or by
means of direct reduction and/or by means of partial oxidation
and/or reforming.
[0022] According to the invention, the intermediate product for the
steel production is produced using a hot furnace and a subsequent
LD process or using an electric arc furnace with regenerative
energy and is stored in this way. A particular advantage is that
the intermediate product produced by means of regenerative energy
can be stored until it is processed further, which means that the
method according to the invention permits a storage of regenerative
energy. Up to now, this very storage of regenerative energy has
presented a very large problem since in particular, electrical
energy that is generated from wind or sun depends on climatic
conditions that are not always the same. Even hydroelectrically
generated electrical energy is not always available. Often, the
consumers are not in the same locations as the production of
regenerative energy. This problem of storage and subsequent
mobility of the stored energy is solved by means of the invention
since the intermediate product produced according to the invention
can be efficiently transported in small units and in any quantity
to any location, for example by marine transport.
[0023] The energy in the method according to the invention is not
in fact stored in a form that is accessible to virtually anyone and
for general use from the storage reservoir; but the global demand
for certain intermediate products is so high that according to the
invention, the intermediate product constitutes the energy storage
for other forms of energy demand, e.g. providing retail electricity
customers with electrical energy from other sources or other
storage reservoirs, thus permitting better management and planning
of the total energy balance.
[0024] In particular, the method according to the invention can be
used in regions of the world in which the raw material for the
intermediate product and the corresponding discontinuously produced
regenerative energy are present in the same location. An example of
this can be the magnesia storage facilities for the production of
fused magnesia (e.g. for use in the flame retardant industry) that
exist, for example, in Canada or China and correspondingly, the use
of hydroelectric power or wind energy or (China) solar energy. In
iron ores that are to be transformed into the corresponding
intermediate product with direct reduction methods, such locations
e.g. Sweden and Norway (hydroelectric power) or Australia (solar
energy) in which the regenerative energy is used on the one hand to
mechanically prepare the corresponding raw material, namely the
iron ore (among other things breaking, grinding, agglomerating),
and also for producing hydrogen for the direct reduction or for
example for pyrolysis of wood to produce corresponding
carbon-containing or hydrogen-containing gas flows.
[0025] In the method according to the invention, this electrical
energy generated from wind, hydro, or solar energy is used to
produce hydrogen from water by electrolysis. Preferably at the site
of the production of the hydrogen, a direct reduction system is
operated, which is used for reducing iron ores - which are likewise
particularly preferably completely prepared with electrical energy
produced in this way. The intermediate product obtained in this
way, in particular hot briquetted iron HBI, HDRI, or CDRI is an
ideal way to store this regenerative energy, can be stored without
restriction in large quantities, and is accessible via any form of
transportation to a system for processing it further, particularly
when it is needed there. In particular, this intermediate product
can be produced at its production site--in large quantities that
exceed the present requirement--when the corresponding electrical
energy is available in sufficient quantity. If this energy is not
available, then there are sufficient quantities of the intermediate
product and thus of the energy in a stored form in order to be able
to meet the need.
[0026] Operating a corresponding electrical arc, likewise using
only energy produced from wind-, hydroelectric-, or solar energy,
succeeds in achieving a CO.sub.2-free steel production or smelting
production (e.g. fused magnesia) and also in storing regenerative
energy.
[0027] According to the invention, the hydrogen from the
regenerative processes can be used with carbon-containing or
hydrogen-containing gas flows such as CH4, COG, synthesis gas etc.,
in a direct reduction system. The ratio of hydrogen from the
regenerative processes to carbon-containing or hydrogen-containing
gas flows can be continuously varied as a function of availability.
For example, if a very large amount of hydrogen is available, this
can be used up to almost 100% for the direct reduction; if
necessary, however, it is also possible to switch to purely
carbon-containing or hydrogen-containing gas flows (for example
natural gas, biogas, gas from pyrolysis, renewable resources).
[0028] Preferably, however, the method is carried out so that
regenerative energy, when present, is used to produce as much
hydrogen as the existing energy permits and this hydrogen is used
for the direct reduction. It goes without saying that
carbon-containing or hydrogen-containing gas flows also include gas
flows from biogas production and pyrolysis or synthesis gas from
biomass, i.e. renewable resources.
[0029] Excess hydrogen that cannot be used immediately can be
temporarily stored.
[0030] This temporary storage of hydrogen can, for example, be
provided by a gas holder and the adjustment of the contents of
carbon-containing or hydrogen-containing gas flows can be carried
out by means of a predictive control. This predictive control can
measure the predicted yield/production quantity of hydrogen or
regenerative energy, but can also be used, for example, to estimate
the production quantity of regenerative energy based on weather
forecasts. Demand forecasts of other external consumers can also
flow into this predictive control so that the electrical energy
produced from regenerative sources is optimally used in the most
economical fashion.
[0031] The temperatures of the gas flow that prevail in this case
are adjusted by heating--for example with reformers, heaters, or
partial oxidation--to 450.degree. C. to 1200.degree. C., preferably
600.degree. C. to 1200.degree. C., in particular 700.degree. C. to
900.degree. C. and then introduced into the direct reduction method
in order to perform a chemical reaction there. In addition, the gas
flow that [sic] exits the direct reduction method can be fed back
into the process as a carbon-containing or hydrogen-containing gas
flow.
[0032] The resulting possible intermediate products according to
the invention are HBI, HDRI, or CDRI.
[0033] In this case, excess pressures of 0 bar to 15 bar are
adjusted. For example, excess pressures of approx. 1.5 bar are
preferred in the MIDREX process and excess pressures of
approximately 9 bar are preferred in the Energiron process.
[0034] When regeneratively produced hydrogen is mixed with
carbon-containing or hydrogen-containing gas flows, the carbon
content can be adjusted in an ideal fashion and in fact can be
adjusted to 0.0005% to 6.3%, preferably 1% to 3%, and directly
incorporated into the intermediate product as C or Fe.sub.3C. An
intermediate product of this kind is ideally adjusted in terms of
the carbon content and is particularly well suited to further
processing since it contributes the carbon content that is required
for the metallurgical process.
[0035] In a preferred embodiment, in order to compensate for
temporary fluctuations in the production of renewable energy, this
energy can be stored in the form of hydrogen if a surplus of it is
available. This storage can occur, for example, in a gas holder.
Such a store can then be used in the event of fluctuations.
Temporary fluctuations can be predictable, e.g. at night in solar
installations, or unpredictable, e.g. fluctuations in wind
intensity in wind energy plants.
[0036] Longer-term fluctuations that can occur among other things
due to the different seasons can preferably be factored into the
energy storage in the form of HBI.
[0037] Another possibility for compensating for fluctuations can
lie in the variable use of natural gas. The thermal state of the
plant can thus be kept advantageously stable.
[0038] Another advantage of the invention lies in the spatial
decoupling of the locations of the production of regenerative
energy and the use of this stored energy. For example, solar power
stations can be constructed in warmer regions with favorable
amounts of solar radiation in which space is plentiful, whereas
steel mills are often found in the vicinity of rivers or seas.
[0039] Since the energy produced is stored in HBI, for example, it
can be transported easily and efficiently.
* * * * *