EP3003981A1

EP3003981A1 - Integrated installation and method for flexibly using electricity

Info

Publication number: EP3003981A1
Application number: EP14724027.9A
Authority: EP
Inventors: Georg Markowz; Jürgen Erwin LANG; Rüdiger Schütte
Original assignee: Evonik Degussa GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2013-05-28
Filing date: 2014-04-30
Publication date: 2016-04-13
Also published as: US20160108809A1; JP2016521669A; AR096421A1; DE102013209883A1; WO2014191148A1

Abstract

The present invention relates to an integrated installation, which comprises an installation for electrothermally producing hydrocyanic acid and an installation for generating electricity, wherein the installation for electrothermally producing hydrocyanic acid is connected via a line to the installation for generating electricity, and electricity is generated in the installation for generating electricity from a product gas obtained in the installation for electrothermally producing hydrocyanic acid. This integrated installation allows for the flexible use of electricity using a method, in which the installation for electrothermally producing hydrocyanic acid is operated at times of high electricity supply and at least a portion of hydrogen obtained along with hydrocyanic acid and/or gaseous hydrocarbons is stored, and stored hydrogen and/or gaseous hydrocarbons are fed to the installation for generating electricity at times of low electricity supply.

Description

Integrated system and method for the flexible use of electricity

The present invention relates to an integrated system and method for the flexible use of electricity. The use of renewable energies, such as wind power, solar energy and hydropower, is becoming increasingly important for power generation. Electrical energy is typically supplied to a variety of consumers via long-range, supra-regional and transnationally coupled power grids, referred to as power grids. Since electrical energy in the power grid itself or without further devices can not be stored to a significant extent, the electrical power fed into the power grid must be matched to the consumer's power requirements, the so-called load. The load varies, as is known, time-dependent, in particular depending on the time of day, day of the week or season. Classically, the load profile is subdivided into the three areas of base load, medium load and peak load, and electrical power generators are suitably used in these three load ranges, depending on the type. For a stable and reliable power supply, a continuous synchronization of power generation and power take-off is necessary. Possible short-term deviations are compensated by so-called positive or negative balancing energy or balancing power. In regenerative power generation facilities, the difficulty arises that, for certain types, such as wind power and solar energy, the power generation power is not present and controllable at any time, but is e.g. Daytime and weather-related fluctuations are subject that are only partially predictable and usually do not match the current energy needs.

Typically, the difference between the generation power from fluctuating renewable energies and the current consumption by other power plants to provide, such as gas, coal and nuclear power plants. With increasing expansion and share of fluctuating renewables in the power supply, ever greater fluctuations between their performance and current consumption must be compensated. So are already next to Gas-fired power plants increasingly coal-fired power plants drove in partial load or shut down completely to compensate for the fluctuations. Since this variable driving style of power plants is associated with considerable additional costs, the development of alternative measures has been studied for some time. One approach is to adapt the performance of one or more consumers as an alternative or in addition to changing the power of a power plant (eg demand side management, smart grids). Another approach is to save part of the output in the case of high generation from renewable energy sources and to recycle it in times of low generation or high consumption. For example, pumped storage power plants are already being used today. In development there are also concepts for the storage of electricity in the form of hydrogen by electrolytic splitting of water.

The measures described here are associated with considerable additional costs and energy losses due to their efficiency. Against this background, efforts are increasingly being made to find ways of compensating for the differences between the provision of electricity and the purchase of electricity through the use of renewable energies, especially wind and solar energy.

With an estimated operating life of 20% or less, based on a maximum possible continuous deployment, there will be unacceptably long payback periods so that profitability can only be achieved through state intervention or exceptional business models. This estimate is based on the fact that the plant is operated only in times of a surplus of renewable energies. It should also be noted that, in the case of renewable energy supply that is low for a long time, power plants must be available to ensure that basic needs are met. The necessary provision of power plant capacities must be economically feasible or possibly financed by state regulations, since in this case too, relatively high fixed costs are offset by a relatively short service life. Conventional power plants, ie power plants based on fossil or biogenic fuels or on nuclear power, can provide electrical energy for a long time. However, the deployment of fossil fuel-based or nuclear-based facilities is expected to be increasingly reduced to benefit generators based on renewable energy due to political reasons, in particular sustainability and environmental concerns. However, these generators must be installed as needed and in turn can be operated economically. From a certain amount of installed capacity based on renewable energies, it makes more economic sense to install such in the form of storage instead of a further increase in capacity for renewable energy, so that in times of electricity surplus by renewable energy this can be used and stored sensibly and In times of power shortage from energy storage or conventional power plants electricity can be provided. If the energy consumption is made more flexible, it can be assumed that the times of a noticeable surplus or power shortage will be lower. In spite of all this, there is a need to ensure power supply for these short times, and this should be done as economically as possible.

In view of the prior art, it is an object of the present invention to provide an improved system that does not suffer from the disadvantages of conventional methods.

In particular, it was an object of the present invention to find ways to increase the flexibility in terms of storage and use of electrical energy over the prior art. Furthermore, the system should be flexibly operable, so that responding to a change in electricity supply and / or electricity demand particularly flexible, for example, to achieve economic benefits. Here, the system should be able to be used for storage or supply of electrical energy even for longer periods of high or low electricity supply. Furthermore, the security of supply should be improved by the present invention. The system and the method should continue to have the highest possible efficiency. Furthermore, the method according to the invention should be able to be carried out using the conventional and widely available infrastructure.

In addition, the process should be able to be carried out with as few process steps as possible, whereby they should be simple and reproducible.

Other tasks not explicitly mentioned arise from the overall context of the following description and the claims.

These, as well as other tasks not explicitly mentioned, which result from the contexts discussed in the introduction, are solved by an integrated plant that integrates a plant for the electrothermal production of hydrocyanic acid and a power generation plant by connecting the plants via a pipeline the plant for generating electricity a product gas, which is obtained in the plant for the electrothermic production of hydrocyanic acid, can be used to generate electricity.

The present invention is accordingly an integrated system comprising a plant for electrothermic production of hydrocyanic acid and a plant for power generation and is characterized in that the plant for electrothermic production of hydrogen cyanide is connected via a line to the plant for power generation and the line in the plant for electrothermic production of hydrocyanic acid obtained product gas of the plant for power generation supplies.

The present invention also relates to a method for the flexible use of electricity, in which the plant for electrothermal production of hydrocyanic acid is operated in an integrated system according to the invention in times of high electricity supply and stored at least a portion of hydrogen hydrogen and / or gaseous hydrocarbons obtained in addition to hydrocyanic acid be stored in times of low supply of electricity stored hydrogen and / or gaseous hydrocarbons of the plant for power generation. The integrated system according to the invention and the method according to the invention have a particularly good property profile, whereby the disadvantages of conventional methods and systems can be significantly reduced.

In particular, it has surprisingly been found that it is thus possible to operate a plant for the electrothermal production of hydrocyanic acid with a high utilization, with renewable energy can be used economically in excess. Furthermore, the system can convert a power surplus from renewable energies, including wind power or photovoltaics, into a storable form. Furthermore, even with a longer period of time, electrical energy can be provided to a small supply of renewable energy in a particularly cost-effective manner.

A plant for the electrothermal production of hydrocyanic acid can be operated dynamically well, so it can be adjusted variably to the electricity supply. In this case, the integrated system can also be used for longer periods of high or low electricity supply for storage or provision of electrical energy. In this case, surprisingly long terms of all components of the integrated system can be achieved, so that their operation can be made very economical. It can also be provided that the system for the electrothermal production of hydrocyanic acid is designed to be controllable, wherein the regulation takes place as a function of the electricity supply.

In a preferred embodiment of the process according to the invention, electricity from renewable energies is used for the electrothermal production of hydrocyanic acid.

In addition, the process can be carried out with relatively few process steps, the same being simple and reproducible.

By using electricity from renewable energies, the present integrated facility allows the provision of chemical derived products with a low release of carbon dioxide, since the hydrocyanic acid obtained at very high degrees of conversion and compared to alternative starting materials with less further energy input or higher heat release can be implemented to many chemically important secondary products.

The integrated system according to the invention serves for the purposeful and flexible use of electrical energy, also referred to herein synonymously as electricity. The integrated system can store electrical energy with a high electricity supply and, in particular with a low electricity supply, feed electrical energy into a power grid. The term storage here refers to the ability of the system, with a high supply of electricity to convert this into a storable form, in this case as chemical energy, which chemical energy can be converted into electrical energy with a small supply of electricity. The storage can be done in the form of coupling product hydrogen, which inevitably arises in the electrothermal production of hydrocyanic acid from methane or higher hydrocarbons. The storage can also take place in the form of products which can be formed in the electrothermal production of hydrogen cyanide in a running parallel to the formation of hydrogen cyanide endothermic reaction, for example by reacting two molecules of methane to ethane and hydrogen. In this context, it should be noted that two moles of methane (CH) have a lower energy content than, for example, one mole of ethane (C ₂ H ₆ ) and one mole of hydrogen, resulting in a conversion of methane to hydrogen and a hydrocarbon of two or more Carbon atoms energy can be stored.

In conventional plants for the production of hydrocyanic acid, a relatively large amount of energy is expended in order to work up the resulting by-product gases in order, where appropriate, to sell hydrogen in pure form. In the present system, this purification can be made much simpler by using the by-product gases energetically.

The integrated system according to the invention comprises a plant for the electrothermal production of hydrocyanic acid. The term electrothermal refers to a process in which hydrogen cyanide is produced in an endothermic reaction of hydrocarbons or coal and the heat required to carry out the reaction is generated by electric current. Preferably gaseous or vaporized hydrocarbons are used, more preferably aliphatic hydrocarbons. Particularly suitable are methane, ethane, propane and butanes, especially methane. In the electrothermal production of hydrocyanic acid from aliphatic hydrocarbons, hydrogen is obtained as co-product.

The electrothermal production of hydrocyanic acid can be carried out by reacting hydrocarbons with ammonia or nitrogen in an arc reactor. The electrothermal production of hydrocyanic acid can take place in a one-step process, in which an ammonia and at least one hydrocarbon-containing gas mixture is passed through the arc. Alternatively, a nitrogen and a hydrocarbon-containing gas mixture, which may additionally contain hydrogen, are passed through the arc. Suitable plants and processes for a one-stage electrothermal production of hydrogen cyanide are known from GB 780,080, US 2,899,275 and US 2,997,434. Alternatively, the electrothermal production of hydrocyanic acid can be carried out in a two-stage process in which nitrogen is passed through the arc and at least one hydrocarbon is fed behind the arc into the plasma generated in the arc. A suitable plant and a process for a two-stage electrothermal production of hydrocyanic acid are known from US 4,144,444.

The arc reactor is preferably operated with an energy density of 0.5 to 10 kWh / Nm ³ , especially 1 to 5 kWh / Nm ³ and in particular 2 to 3.5 kWh / Nm ³ , wherein the energy density on the gas volume passed through the arc refers. The temperature in the reaction zone of the arc reactor varies due to the gas flow, wherein in the center of the arc up to 20,000 ° C can be achieved and at the edge, the temperature can be about 600 ° C. At the end of the arc, the average temperature of the gas is preferably in the range of 1300 to 3000 ° C, more preferably in the range of 1500 to 2600 ° C. The desired production capacity is usually achieved by a parallel arrangement of several arc reactors, which can be controlled together or separately.

The residence time of the starting material in the reaction zone of the arc reactor is preferably in the range of 0.01 ms to 20 ms, more preferably in the range of 0.1 ms to 10 ms and especially preferably in the range of 1 to 5 ms. Thereafter, the gas mixture exiting the reaction zone is quenched, i. subjected to a very rapid cooling to temperatures of less than 250 ° C in order to avoid decomposition of the thermodynamically unstable intermediate hydrogen cyanide. For quenching, a direct quenching process such as, for example, the introduction of hydrocarbons and / or water or an indirect quenching process, such as rapid cooling in a vapor recovery heat exchanger may be used. Direct quenching and indirect quenching can also be combined. In a first embodiment, the gaseous mixture leaving the reaction zone is only quenched with water. This embodiment is characterized by relatively low investment costs. The disadvantage, however, is that in this way a considerable part of the energy contained in the product gas is not used or exergetically inferior. In a preferred embodiment, the gaseous mixture leaving the reaction zone is mixed with a hydrocarbon-containing gas or a hydrocarbon-containing liquid, at least part of the hydrocarbons being split endothermically. Depending on the process management, a more or less broad product spectrum is generated, eg. As well as hydrocyanic acid and hydrogen also shares in ethane, propane, ethene and other lower hydrocarbons. In this way, the resulting heat can be supplied to a much higher extent of a further use such as the endothermic cleavage of hydrocarbons.

After this temperature reduction, for example to 150 to 300 ° C, solid components, in particular carbon particles, separated and the gas mixture, depending on the starting materials in addition to hydrogen cyanide and hydrogen other substances, such as Ethyne, ethene, ethane, carbon monoxide and volatile sulfur compounds, such as H ₂ S and CS ₂ may contain, further processing for the production of hydrogen cyanide supplied. Hydrocyanic acid can be separated from the gas mixture by selective absorption in water. In addition to hydrogen cyanide formed ethyne can then be separated from the gas mixture by selective absorption in a solvent. Suitable solvents are, for example, water, methanol, N-methylpyrrolidone or mixtures thereof. Suitable methods for the separation of hydrogen cyanide and ethyne from the gas mixture are known from the prior art, for example from Ullmann's Encyclopedia of Industrial Chemistry, 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Volume 10, pages 675 to 678, DOI: 10.1002 / 14356007.a08_159.pub3 and volume 1, pages 291 to 293, 299 and 300, DOI: 10.1002 / 14356007.a01_097.pub4.

In an alternative embodiment, the electrothermal production of hydrogen cyanide takes place by reaction of hydrocarbons with ammonia in an electrically heated coke fluidized bed according to the so-called Shawinigan process.

In a further alternative embodiment, the electrothermal production of hydrocyanic acid is carried out by reacting hydrocarbons with ammonia in the presence of a platinum-containing catalyst by the so-called BMA process with electrical heating of the reactor. The electrical heating can be effected by resistance heating, as described for example in WO 2004/091773, by electric induction heating, as described, for example, in WO 95/21 126, or by microwave heating, as described, for example, in US Pat. No. 5,529,669 and US Pat. No. 5,470,541. The integrated system according to the invention also comprises a plant for power generation, which is supplied via a line a obtained in the plant for the production of hydrocyanic acid product gas. Suitable plants for power generation are all systems with which electrical power can be generated from the product gas. Preferably, a plant is used for power generation, which has a high efficiency. The product gas supplied to the plant for generating electricity preferably contains hydrogen and / or hydrocarbons. The hydrocarbons may be unreacted feedstocks of the electrothermal production of hydrocyanic acid, by-produced ethyne, hydrocarbons added in a quench, quenched hydrocarbons, or mixtures thereof.

In a preferred embodiment, the plant for power generation comprises a fuel cell. In this embodiment, the power generation plant is preferably supplied with a product gas consisting essentially of hydrogen. In a further preferred embodiment, the plant for power generation comprises a power plant with a turbine. Particularly preferably, the plant comprises a gas turbine which can be operated with hydrogen and / or hydrocarbon-containing gases. Most preferably, a gas turbine is used which can be operated with mixtures of hydrogen and hydrocarbon-containing gases of varying composition.

Preferably, the power plant with a turbine is a gas and steam turbine power plant (Gu D power plant), also called gas and steam combined cycle power plant. In these power plants, the principles of a gas turbine power plant and a steam power plant are linked. A gas turbine generally serves, among other things, as a heat source for a downstream waste heat boiler, which in turn acts as a steam generator for the steam turbine.

The plant for power generation, in addition to the product gas obtained in the production of hydrogen cyanide still further substances can be supplied, for example, additional hydrogen for the operation of a fuel cell or additional fuel for the operation of a turbine or the heating of a steam generator.

The capacity of the plant for power generation can be selected depending on the production capacity of the plant for the electrothermal production of hydrocyanic acid. Preferably, the power of the plant for power generation is chosen so that the power requirements of the plant for the electrothermal production of hydrocyanic acid at full load completely covered by the plant for power generation can be. The power can be achieved by a single device or a combination of multiple devices, the merger (pool) can be achieved via a common control. In addition, electrical energy for the plant for the electrothermal production of hydrogen cyanide can be obtained from the mains. Likewise, the plant for power generation can be dimensioned so that in addition to the plant for electrothermic production of hydrogen cyanide also supplies other power consumers or beyond the needs of the plant for the electrothermal production of hydrocyanic exceeding electrical energy is fed into a grid. In the integrated plant, the plant for the electrothermal production of hydrocyanic acid is connected via a pipe with the plant for power generation, with which the plant for generating electricity is supplied to a product gas obtained in the plant for the electrothermal production of hydrogen cyanide. The product gas preferably consists of hydrogen and / or hydrocarbon-containing gases. The product gas can be supplied via the line of the power generation plant in gaseous or liquefied form, wherein the liquefaction can be done by increasing the pressure or reducing the temperature.

The line which connects the plant for the electrothermic production of hydrogen cyanide with the plant for power generation, preferably has a length of less than 10 km, more preferably less than 1 km.

In a preferred embodiment, the plant for the electrothermal production of hydrocyanic acid has a device for separating the gas mixture obtained in the electrothermal production, wherein this device is connected to the plant for generating electricity. In the apparatus for separating the gas mixture obtained in the electrothermal production of hydrogen cyanide, hydrocyanic acid is separated from hydrogen and hydrocarbons. The separated from hydrogen cyanide, containing hydrogen and hydrocarbons mixture can be fed directly to the plant for power generation. Alternatively, hydrogen can be separated from the mixture separated from hydrocyanic acid and, optionally, hydrogen or a hydrocarbon-containing gas resulting therefrom are fed to the plant for generating electricity. Likewise, hydrogen and a hydrocarbon-containing gas over Separate lines are supplied from the device for separating the gas mixture obtained in the electrothermal production of hydrogen cyanide of the plant for power generation. The separation of hydrogen and hydrocarbons can also be incomplete in the integrated system according to the invention, without an incomplete separation adversely affecting the operation of the system, so that the expenditure on equipment and energy consumption for the separation is kept low.

In a preferred embodiment of the integrated plant, the plant for generating electricity comprises separate devices for the production of electricity from hydrogen and for the production of electricity from a hydrocarbon-containing gas, preferably via separate lines with a device for separating the in the electrothermal production of hydrogen cyanide obtained gas mixture are connected. Particularly preferably, the plant for power generation comprises a fuel cell for the production of electricity from hydrogen and a combined cycle power plant for the production of electricity from a hydrocarbon-containing gas. In this embodiment, gas and steam turbine power plants can be used in the integrated system according to the invention, which are not suitable for the conversion of hydrogen-rich gases. In a preferred embodiment, the integrated system according to the invention additionally has at least one reservoir for a product gas obtained in the plant for the electrothermal production of hydrocyanic acid, the reservoir being connected via lines both to the plant for the electrothermal production of hydrocyanic acid and to the plant for generating electricity , Particularly preferably, the memory is connected to the device described above for the separation of the gas mixture obtained in the electrothermal production of hydrogen cyanide, so that hydrogen and / or hydrocarbon-containing gases can be stored in the memory. Preferably, the memory is a hydrogen storage. Particularly preferably, the integrated system comprises both a hydrogen storage and a storage for hydrocarbon-containing gases. The integrated system may additionally comprise a device with which the composition of a product gas obtained in the electrothermal production of hydrogen cyanide can be changed before it is fed to the plant for power generation. Preferably, the integrated system additionally comprises a device with which hydrogen obtained as a coproduct in the electrothermal production of hydrogen cyanide can be converted to hydrocarbons by a Fischer-Tropsch synthesis or a methanation. The hydrocarbons thus obtained can be fed together with hydrocarbons separated from hydrocyanic acid or separately from the plant for the generation of electricity. A conversion of hydrogen to hydrocarbons simplifies the supply of product gas obtained in the electrothermal production of hydrocyanic acid in power plants in which hydrocarbons are burned for power generation and for which the content of hydrogen in the fuel gas must be kept within certain narrow limits for reliable operation , Suitable plants for Fischer-Tropsch synthesis or methanation are known from the prior art, for methanation, for example from DE 43 32 789 A1 and WO 2010/1 15983 A1.

In a preferred embodiment, the integrated plant comprises a steam generator in the plant for the electrothermal production of hydrocyanic acid, with which from the waste heat of the electrothermal process steam is generated, a device in which electricity is generated from steam, in the plant for power generation, and a Steam line, with the vapor generated in the steam generator of a device in which stream of steam is generated, is supplied. Preferably, an indirect quench of the reaction gas obtained in a hydrogen cyanide reactor is used as a steam generator. The device in which electricity is generated from steam is preferably a steam turbine or a steam engine and more preferably a steam turbine. Most preferably, the steam turbine is part of a gas and steam turbine power plant. With this embodiment, waste heat generated in the plant for the production of hydrocyanic acid can be used to generate electricity and the fuel demand for the operation of the device, in which electricity is generated from steam, can be reduced. In a preferred embodiment, the integrated system according to the invention additionally comprises a storage for hydrocyanic acid. This store makes it possible to continue downstream conversion of hydrocyanic acid to other products, even if little or no hydrocyanic acid is produced in the plant for the electrothermal production of hydrocyanic acid at low power supply. Preferably, the storage of hydrocyanic acid takes place in liquid form.

In a further preferred embodiment, the integrated system according to the invention is connected to a weather forecast unit. Such a connection with a weather forecasting unit makes it possible to adjust the operation of the system so that on the one hand the possibility of using cheap excess electricity and the ability to provide electricity from the plant for power generation with low electricity supply and correspondingly high electricity price can be used and on the other always provide sufficient hydrocyanic acid for the continuous operation of a downstream, hydrocyanic acid-consuming plant. Thus, depending on the result of the weather forecast, for example, a storage for hydrocyanic acid can be brought to a high or low level. In addition, a plant for the further processing of hydrocyanic acid can be prepared and adjusted for changed operating modes. Thus, in the case of a longer-term supply of electricity, these parts of the system can be set to a reduced production output, so that a business interruption due to the absence of hydrocyanic acid can be avoided.

In addition, the integrated system may be connected to a unit for generating a consumption forecast, wherein this unit preferably has a data memory that includes data on the historical consumption. The historical consumption data may include, for example, the course of the day, the course of the week, the course of the year, and other trends related to electricity demand and / or electricity generation. The consumption forecast data can also take into account specific changes, for example, in the access or omission of a large consumer. Additionally or alternatively, the data store may also contain data about the historical history of electricity prices. In the inventive method for the flexible use of electricity in the integrated system according to the invention in times of high electricity supply operated the plant for the electrothermal production of hydrocyanic acid and stored at least a portion of hydrocyanic acid obtained hydrogen and / or gaseous hydrocarbons and stored in times of low electricity supply Hydrogen and / or gaseous hydrocarbons fed to the plant for power generation. Preferably, hydrogen is stored in the process.

In the electricity supply can be present both a surplus of electricity and a power shortage. A surplus of electricity results if more electricity is generated from renewable energies at a time than total electricity is consumed at that time. Electricity surplus also occurs when large amounts of electrical energy are supplied from fluctuating renewable energies and throttling or shutting down power plants is associated with high costs. A power shortfall arises when comparatively small amounts of renewable energy are available and inefficient or high-cost power plants have to be operated. The cases of surplus power and power shortage described here can be identified in various ways. For example, the prices on the power exchanges can be an indicator of the current situation, with a surplus of electricity leading to lower electricity prices and electricity shortfalls to higher electricity prices. An electricity surplus or electricity shortage can also exist without any direct effect on the electricity price. For example, there is a surplus of electricity even if the operator of a wind farm produces more power than he predicted and sold. Similarly, there may be a power shortage if it produces less power than it predicted. According to the invention, the terms excess current and under current include all these cases.

The process according to the invention is preferably operated in such a way that at least part of the electricity required for the electrothermal production of hydrocyanic acid is generated from product gas with the plant comprising electricity generated by the integrated plant, which is the product of hydro-thermal production of hydrocyanic acid is obtained. When, in times of high electricity supply, the plant is operated for the production of hydrocyanic acid by electro-nemesis, it is preferable to operate or shut down the power-generation plant included in the integrated plant with reduced power, and a larger part of the power required for the electrothermal production of hydrocyanic acid to provide a power supply network with high power supply taken. Likewise, when in times of low electricity supply the plant comprised of the integrated plant is operated to generate electricity, the plant for the electrothermal production of hydrocyanic acid is preferably operated or switched off at reduced power and a smaller part of the electricity required for electrothermal production of hydrocyanic acid is taken from the power grid or electricity from the integrated power plant in the electricity grid.

The storage of hydrogen hydrogen and / or gaseous hydrocarbons obtained in addition to hydrogen cyanide is preferably carried out in a reservoir comprised by the integrated plant, more preferably in a reservoir arranged as described above between the plant for the electrothermal production of hydrocyanic acid and the plant for generating electricity. Alternatively, the storage can also be done in a separate memory, which is connected to the integrated system via a gas distribution line, such as a natural gas network.

The nature of the memory is not critical, so that for this purpose a pressure tank, a liquid gas storage, a memory in which hydrocarbons are absorbed in a solvent, or a storage with gas adsorption on a solid can be used. For storage of hydrogen are also suitable chemical storage in which hydrogen is stored by a reversible chemical reaction. Preferably, separate storage tanks are used for hydrogen and gaseous hydrocarbons. The capacity of the reservoir is preferably such that the amount of hydrogen and / or gaseous hydrocarbons produced by the plant for the electrothermal production of hydrocyanic acid under full load can be absorbed within 2 hours, more preferably the amount produced within 12 hours and more particularly prefers the amount produced within 48 hours. In a preferred embodiment of the process according to the invention, the plant for electrotechnical production of hydrocyanic acid has an arc reactor and the gas mixture obtained from the arc reactor is mixed with a hydrocarbon-containing gas and / or a hydrocarbon-containing liquid for cooling. In this case, as described above, at least a portion of the hydrocarbons is endothermically split, so that cleavage products are obtained which have a higher energy content than the starting materials and supply to the plant for power generation provide a greater amount of electrical energy than would be obtained with supply of the starting materials. This embodiment thus enables storage of electric energy supplied to the arc reactor in the form of high-energy fission products. Preferably, the type and / or amount of hydrocarbonaceous gas and / or liquid are selected depending on the expected electricity supply. This is particularly advantageous in a method in which a direct quench is used by addition of hydrocarbon-containing gas and / or liquid in combination with an indirect quench with steam generation, since then by the choice of type and / or amount of added in the direct quench Controlling hydrocarbons, the amount of heat generated in the arc reactor is stored in the form of fission products for later power generation and what is the proportion that is used immediately in the form of steam without storage for power generation.

Preferably, in the case of a high power supply, the electrical energy used to produce hydrogen cyanide is at least partly derived from renewable energies, particularly preferably from wind power and / or solar energy. However, it should be noted that according to the current German legal situation, electricity generated by renewable energies must be fed into the electricity grid even without current requirements and must be remunerated. Conventionally generated electricity may therefore be present as a "surplus" at times because for a power plant operator, shutting down a power plant may be more inefficient than delivering electricity below cost.This excess electrical energy obtained through the continued operation of conventional plants may be economically utilized by the present process , in particular, be stored. In a preferred embodiment of the method according to the invention, a gas-and-steam turbine power plant is used as a plant for power generation and it is at a high electricity supply, the plant for the electrothermal production of hydrocyanic acid with a capacity of more than 80% of the rated power and the plant for power generation operated with 0-50% of the nominal electrical power and operated at a low power supply, the plant for electrothermal production of hydrocyanic acid with a capacity of 0-50% of the rated power and the plant for power generation with more than 80% of the rated electrical capacity.

With a high electricity supply, the combined-cycle power plant is preferably operated with a power of at most 40% and particularly preferably at most 30% of the rated electrical power.

With a low power supply, the plant for the electrothermal production of hydrocyanic acid is preferably operated with a power of at most 40%, and more preferably at most 30% of the rated power. When the combined cycle power plant is operated on a combined heat and power plant, the rated electrical capacity of the power plant may either be a change in the amount of gas used or a change in the proportion of steam taken off as process steam and not used for power generation be set. Conveniently, both the plant for the electrothermal production of hydrocyanic acid and the plant for power generation are operated at a capacity in which the total amount of hydrogen obtained in the plant for the electrothermal production of hydrocyanic hydrogen in addition to hydrocyanic acid and / or or gaseous hydrocarbons of the plant for power generation is supplied.

By this embodiment of the method according to the invention, a high operating time of both the plant for electrothermic production of hydrocyanic acid and the plant for power generation and thus an economic operation of both plants can be achieved. Preferably, the method according to the invention comprises the steps a) setting a first threshold and a second threshold for a supply of electricity,

b) determination of electricity supply,

c) change in the electrical power of the plant to generate electricity depending on the electricity supply, if the electricity supply the first

Threshold exceeds and changes in the performance of the plant for the electrothermal production of hydrocyanic acid depending on the electricity supply, if the supply of electricity falls below the second threshold, and

d) repeating steps b) and c).

Preferably, the thresholds are set depending on the actual level of the hydrocyanic acid storage or depending on the forecasts of the evolution of consumption and production of hydrocyanic acid in the next few hours. For example, if the level of the hydrocyanic acid storage tank falls to a low level, the threshold below which the output of the hydro-genic acid-producing plant of hydrocyanic acid is reduced is set to a lower value.

The supply of electricity can be determined either directly through coordination with electricity producers and / or electricity consumers or indirectly through trading platforms and / or through OTC procedures and an associated electricity price. In a preferred embodiment, the electricity supply is determined by coordination with power generators from wind energy and / or solar energy. In a further preferred embodiment, the electricity supply is determined via the electricity price on a trading platform. If the supply of electricity is determined by matching with generators from wind energy and / or solar energy, the electric power of the plant for power generation is preferably changed when exceeding the first threshold according to the surplus of electricity and falls below the second threshold, the performance of the plant for electrothermic production of hydrogen cyanide accordingly changed the power penalty. If the electricity supply is determined via the electricity price on a trading platform, the electric power of the plant for power generation is preferably changed to a predetermined lower value when exceeding the first threshold and below the second threshold, the power of the plant for electrothermic production of hydrogen cyanide to a predetermined changed lower value.

The absolute magnitude of the first threshold above which power reduction of the power plant is performed is not essential to this embodiment of the present method and may be determined by economic criteria. The same applies to the second predetermined value, below which there is a reduction in the power of the plant for the electrothermal production of hydrocyanic acid.

If the power of the two systems is coordinated, preferably the first predetermined and the second threshold are chosen equal. Preferably, the electricity supply is calculated from the data of a weather forecast. Based on the predicted electricity supply, the above-mentioned threshold values for an electricity supply are then preferably selected such that a planned amount of hydrocyanic acid is produced in the forecast period and, on the other hand, the storage capacity for hydrogen and / or gaseous hydrocarbons obtained besides hydrocyanic acid is not exceeded.

By a joint operation of the plant for electrothermic production of hydrogen cyanide and the plant for power generation at a medium power supply surprisingly high operating times can be achieved, so that a high profitability of the system is achieved. Preferably, the power generation plant is operated within a calendar year at least 4000 full load hours, preferably at least 5000 full load hours and more preferably at least 5500 full load hours. The full load hours are calculated according to the formula

Full load hours = W / P where W denotes the electrical work in MWh and P provided within a calendar year, the nominal electrical power of the installation in MW.

If the plant for the electrothermal production of hydrogen cyanide comprises at least one arc reactor, the arc reactors are preferably operated within a calendar year on average at least 2500 full load hours, preferably at least 4000 full load hours and more preferably at least 5000 full load hours. The full load hours are calculated according to the formula

Full load hours = production / capacity where "production" is the quantity of hydrocyanic acid produced in one calendar year in tonnes and "capacity" is the total nominal capacity of the arc reactors in tonnes of hydrocyanic acid per hour.

Further preferred embodiments of the method according to the invention will become apparent from the above-described description of an integrated system according to the present invention.

The present integrated plant and method are suitable for the production of hydrocyanic acid in a very economical and resource-saving manner. Hydrocyanic acid can be converted into many valuable intermediates, whereby a surprising reduction of carbon dioxide emissions can be achieved.

This surprising reduction is based on several synergistic factors. This includes the fact that renewable electricity can be used to produce hydrocyanic acid, whereby the production of hydrocyanic acid can be flexibly adapted to a supply of electricity. Furthermore, hydrogen can be obtained at a very high degree of efficiency, which can be used without the release of carbon dioxide to generate electrical energy. Furthermore, heat is often released during the production of the valuable secondary products. This waste heat can often be used to cover the heat demand in other parts of the process (eg distillative separation processes). Accordingly, the carbon dioxide emissions are reduced, otherwise, if an oxidation of hydrocarbons to produce the process heat would be necessary.

It can also be provided that the hydrocyanic acid produced is used to produce sodium cyanide, acetone cyanohydrin or methionine. In addition, by-products from these processes can be used to generate electricity. In this case, gaseous by-products or suitable liquid by-products after evaporation can preferably be fed into the gas turbine. Solid residues can be converted into combustible gases, in particular using hydrogen, and then emitted in a gas turbine. Preferably, the hydrocyanic acid produced in the plant for the electrothermal production of hydrocyanic acid is converted into a further product in at least one further process, and a by-product from this process is used in the power generation plant for generating electricity. Furthermore, the waste heat obtained in a reaction of the hydrocyanic acid to form a secondary compound can at least partially be used to generate electricity. Preferably, the hydrocyanic acid produced in the plant for the electrothermal production of hydrogen cyanide is converted into a further product in at least one further process, and heat generated in this process is used in the power generation plant for generating electricity.

Preferred embodiments of the present invention are explained below by way of example with reference to FIG.

Figure 1: Schematic structure of an integrated system according to the invention.

Figure 1 shows a schematic structure of an integrated system 10 according to the invention, comprising a system 12 for the electrothermal production of hydrocyanic acid and a system 14 for power generation, wherein the integrated system 10 is connected to a central power grid 16. Here, the individual devices can be connected directly to the central power grid 16 or, as shown in Figure 1, are connected via a switching point 18 for power transmission to the central power grid 16. The plant 12 for electrothermal Production of hydrocyanic acid is then connected via a first electrical connection line 20 to the switching point 18 for power transmission, the plant 14 for power generation is connected via a second electrical connection line 22 to the switching point 18 for power transmission and the switching point 18 for power transmission is connected to the central power grid 16th connected. This embodiment may have advantages in installation costs and / or operational expense.

In the embodiment shown in Figure 1, the integrated system 10 comprises a hydrogen storage 24, which can be filled via a first connection line 26 for hydrogen with hydrogen from the plant 12 for the electrothermal production of hydrogen cyanide. To generate electrical energy stored in the hydrogen storage 24 hydrogen can be supplied via the second connecting line 28 for hydrogen of the plant 14 for generating electricity. Furthermore, the integrated system 10 in the embodiment shown on a controller 30, which via a first communication link 32 with the system 12 for electrothermic production of hydrogen cyanide, via a second communication link 34 to the plant 14 for power generation via a third communication link 36 with the Switching point 18 for power transmission and via a fourth communication link 38 is connected to the hydrogen storage 24.

The features of the invention disclosed in the foregoing description as well as the claims, figures and embodiments may also be used in any combination for carrying out the invention. LIST OF REFERENCE NUMBERS

10 integrated system

12 Plant for the electrothermal production of hydrocyanic acid

14 plant for power generation

16 central power grid

18 switching point for power transmission

20 first electrical connection line second electrical connection line

Hydrogen storage

first connecting line for hydrogen second connecting line for hydrogen

control

first communication connection second communication connection third communication connection fourth communication connection

Claims

claims:

1 . Integrated plant (10), comprising a plant (12) for the electrothermic production of hydrocyanic acid and a plant (14) for generating electricity, characterized in that the plant (12) for electrothermic production of hydrocyanic acid via a line (26, 28) with the Plant (14) is connected to generate electricity and the line in the system (12) for the electrothermal production of hydrocyanic acid product gas of the system (14)

Generating electricity.

2. Integrated system according to claim 1, characterized in that the

Plant (14) for generating electricity comprises a fuel cell.

3. Integrated system according to claim 1 or 2, characterized in that the plant (14) for generating electricity comprises a power plant with a turbine.

4. Integrated system according to claim 3, characterized in that the power plant with a turbine comprises a gas turbine which is operable with hydrogen and / or hydrocarbon-containing gases.

5. Integrated system according to claim 3 or 4, characterized in that the power plant with a turbine is a gas-and-steam turbine power plant.

6. Integrated system according to one of the preceding claims, characterized in that the plant (12) for the electrothermal production of hydrogen cyanide comprises an arc reactor.

7. Integrated system according to one of claims 1 to 6, characterized

in that the plant (12) for the electrothermal production of hydrocyanic acid comprises a reactor with an electrically heated coke fluidized bed.

8. Integrated system according to one of claims 1 to 6, characterized

in that the plant (12) for the electrothermal production of hydrogen cyanide comprises an electrically heated reactor with a platinum-containing catalyst.

9. Integrated installation according to one of the preceding claims, characterized in that the plant (12) for the electrothermal production of hydrogen cyanide has a device for separating the gas mixture obtained in the electrothermal production and the device for

Separation of the product obtained in the electrothermal production

Gas mixture is connected to the plant (14) for generating electricity.

10. Integrated system according to one of the preceding claims, characterized

in that the integrated system (10) has at least one hydrogen and / or hydrocarbon-containing gas store (24) which is connected via a line (26) to the system (12) for the electrothermal production of

Hydrochloric acid is connected and is connected via a line (28) with the system (14) for generating electricity.

1 1. Integrated system according to one of the preceding claims, characterized

in that the plant for the electrothermal production of hydrocyanic acid comprises a steam generator with which steam is generated from the waste heat of the electrothermal process, the plant for

Electricity generation comprises a device in which electricity is generated from steam, and the integrated system comprises a steam line, with the steam generated in the steam generator of the device in which stream of steam is generated, is supplied.

12. Integrated system according to one of the preceding claims, characterized

characterized in that it is connected to a weather forecast unit.

13. A method for the flexible use of electricity, characterized in that in an integrated system (10) according to one of claims 1 to 12 in times of high electricity supply, the plant (12) is operated for the electrothermal production of hydrocyanic acid and at least a part of next Hydrogen cyanide obtained hydrogen and / or gaseous hydrocarbons

stored and in times of low supply of electricity stored hydrogen and / or gaseous hydrocarbons of the system (14) are supplied to generate electricity. A method according to claim 13, characterized in that the plant (12) for electrothermic production of hydrocyanic acid comprises an arc reactor, and the gas mixture obtained from the arc reactor for cooling with a hydrocarbon-containing gas or a

hydrocarbonaceous liquid is added.

A method according to claim 14, characterized in that the type and / or amount of the gas and / or the liquid is selected depending on the expected electricity supply.

A method according to any one of claims 13 to 15, characterized in that the electricity supply from the data of a weather forecast is calculated in advance.

Method according to one of claims 13 to 16, characterized in that the plant (14) for power generation is a gas and steam turbine power plant and in the integrated plant (10) at a high power supply, the plant (12) for the electrothermal production of Hydrocyanic acid with a capacity of more than 80% of the nominal power and the installation (14) for the

Power generation is operated at 0-50% of the nominal electrical power and at a low power supply, the plant (12) for electrothermic production of hydrocyanic acid with a power of 0-50% of the rated power and the plant (14) for power generation with more than 80% of electrical

Rated power is operated.

Method according to one of claims 13 to 17, comprising the steps of a) setting a first threshold value and a second threshold value for a current supply,

b) determination of electricity supply,

c) change in the electrical power of the system (14) to

Electricity generation depending on electricity supply, if that

Electricity supply exceeding the first threshold and changing the performance of the plant (12) for the electrothermal production of

Hydrocyanic acid depending on the electricity supply, if the electricity supply falls below the second threshold, and d) repeating steps b) and c).

19. The method according to claim 18, characterized in that the first

Threshold and the second threshold are the same.

20. The method according to any one of claims 13 to 19, characterized in that the plant (12) for electrothermic production of hydrogen cyanide comprises at least one arc reactor and the arc reactor within a calendar year on average at least 2500 full load hours, preferably at least 4000 full load hours and more preferably at least 5000th Full load hours is operated.

21. Method according to one of claims 13 to 20, characterized in that the plant (14) for power generation within a calendar year at least 4000 full load hours, preferably at least 5000 full load hours and more preferably at least 5500 full load hours is operated.

22. The method according to any one of claims 13 to 21, characterized in that the hydrocyanic acid produced in the plant (12) for the electrothermal production of hydrocyanic acid is converted into a further product in at least one further process and a by-product from this process in the plant ( 14) is used to generate electricity to generate electricity.

23. The method according to any one of claims 13 to 22, characterized in that the hydrocyanic acid produced in the plant (12) for the electrothermal production of hydrocyanic acid is converted into a further product in at least one further process and heat generated in the process in the plant ( 14) is used to generate electricity to generate electricity.