KR20160032160A - Method for producing at least one air product, air separation system, method and device for producing electrical energy - Google Patents

Abstract

The present invention relates to a method of manufacturing one or more air products wherein the main air compressor (10), the main heat exchanger (20) and the distillation column system (30) System 100 is used wherein in the first operating mode one or more liquid air products (LIN, LOX) produced in the distillation column system 30 are saved and in a second operating mode, (LIN, LOX, LAIR) and / or one or more additional liquid air products are fed to the distillation column system 30. The method is characterized in that, in a second operating mode, one or more gas pressure flows (b to g) at a temperature level lying below the hot-side temperature of the main heat exchanger (20) are delivered to the refrigerant compressor (45) 45 to a second atmospheric pressure excess pressure level and to a second atmospheric pressure excess pressure level in at least one distillation column (31, 32) of the distillation column system (30) . In addition, the present invention relates to a corresponding air separation system 100 and a method and apparatus for producing electrical energy.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing at least one air product, an air separation system, a method and an apparatus for manufacturing electric energy,

The present invention relates to a method of manufacturing one or more air products, an air separation system, and also a method and apparatus for manufacturing electrical energy, according to the preamble of the independent claims.

A " condenser evaporator "specifies a heat exchanger that causes a first condensing fluid stream to indirectly exchange heat with the second vaporizing fluid stream. Each evaporative condenser has a gas liquefaction chamber and a vaporization chamber, each of which is comprised of gas liquefaction passages and evaporation passages. In the gas liquefaction chamber, the first fluid stream is subjected to condensation (gas liquefaction), and in the evaporation chamber, the second fluid stream is vaporized. The evaporation and gas liquefaction chambers are formed by groups of passages that are in heat exchange relationship with each other. The evaporation chamber of the evaporative condenser may be configured as a bath evaporator, a falling film evaporator, or a forced flow evaporator.

In a low pressure column sump evaporator, within the evaporation chamber, the sump liquid in the low pressure column is at least partially vaporized. In the low pressure column intermediate evaporator, in the evaporation chamber, the intermediate liquid in the low pressure column is at least partially vaporized.

A method of the type mentioned in the introduction and corresponding arrangements with three columns are known.

In known methods for producing electrical energy, for example, in known oxyfuel processes, what is called processes combined with integrated gasification (integrated gasification combined cycle (IGCC) process ), Oxygen or oxygen-enriched gas mixtures are required, for example for combustion or for partial oxidation. Methods and apparatus for the cryogenic separation of air, to provide oxygen or the corresponding oxygen-enriched gas mixtures, are described, for example, in Hausen / Linde, Tieftemperaturtechnik [ , 1985, Chapter 4 (pages 281 to 337).

In these methods and apparatuses (referred to herein as "air separation systems" for the sake of brevity), for example, as two column systems, in particular triple or triple column systems as well as typical lint twin column systems Distillation column systems, which can be constructed as multicolumn systems, are used. In addition, devices for obtaining additional air components, particularly inert gases krypton, xenon and / or argon, may be provided.

The methods and apparatuses for making electrical energy can be used in large load ranges and in high load ranges to absorb power fluctuations such as may occur due to the availability or unavailability of other energy feed- Be able to be configured for load changes. Air separation systems carrying oxygen and / or corresponding gaseous mixtures therewith must also enable a flexible operating mode to a corresponding degree.

Conventional air separation systems are also also affected by electricity grid usage and correspondingly large fluctuating electricity prices.

The degree of flexibilization possible depends on the gas liquefaction capacity of the air separation system in this case. The greater the available gas liquefaction capacity, the more advantageously the power can be stored in the form of liquid air products. In particular, air separation systems for supplying methods and apparatus for energy production have only low gas liquefaction capabilities, which are designed for the production of large quantities of gaseous oxygen and nitrogen products drawn from the air separation system to ambient temperature . The cooling requirements of the corresponding systems are relatively low, so they are also not designed to carry a sufficient amount of cold air for exceptional specifications for relatively large quantities of gaseous air products.

In corresponding systems, therefore, a separate gas liquefaction system (LIN, LOX or LAIR gasifier) can be installed and connected during the gas liquefaction step. Flexibilization can also be achieved in that the cooling capability of the method or system (and thus the corresponding gas liquefaction capability) can be designed to be greater than for an actual required amount of gaseous oxygen and nitrogen products .

If relatively large amounts of liquid air products are delivered into the corresponding air separation system, possibly much more chilled air may be introduced into the air separation system than is required. This would cause the respective temperature profiles in the shifted heat exchangers, without countermeasures, and the temperature of one or more of the streams coming out of the heat exchangers would be getting lower and lower. From a certain limit, the reliable operating mode of the air separation system will no longer be guaranteed. This problem can be addressed by using heat-producing devices such as air, steam, gas, heat exchangers that are heated or electrically heated, or heat exchangers that are heated in other manners. However, this solution proves to be disadvantageous, especially on energy bases.

It is an object of the present invention to specify corresponding devices with relatively low energy consumption in all corresponding modes of operation, with a wide variety of variations on the method and its energy consumption of the type mentioned in the introduction.

This object is achieved by a method of manufacturing one or more air products, air separation systems, and also methods and apparatus for producing electrical energy, having features of independent terms. Preferred embodiments are the subject matter of the dependent claims and also the following description in each case.

Before the advantages achievable in the context of the present invention are described, some of the expressions used in the present application will be explained.

An "air separation system" is filled with selectively dried and purified air provided in the form of one or more pressurized air streams by a "main air compressor ". The air separation system, as mentioned, has a distillation column system for separating air into its physical components, especially nitrogen and oxygen. For this purpose, air is cooled to near its dew point and introduced into the distillation column system, as described above. Conversely, pure "air gas liquefaction systems" or "gas liquefiers" do not include distillation column systems. In addition, the structure of the air gas liquefaction system may correspond to the structure of an air separation system for transporting air gas liquefied products. Of course, the liquid air can also be produced as a by-product in the air separation system.

A "liquid air product" is any product that can be produced by compression, cooling and subsequent expansion of air, at least in the form of a cold liquid. In particular, the liquid air product is in this case, as mentioned, liquid oxygen (LOX), liquid nitrogen (LIN), liquid argon (LAR) or liquid air ). The expressions "liquid oxygen" or "liquid nitrogen" respectively denote low temperature liquids having an oxygen and / or nitrogen content greater than the amount of the atmosphere here. Thus, they need not necessarily be pure liquids having high contents of oxygen and / or nitrogen. Thus, liquid nitrogen is taken to mean pure or substantially pure nitrogen as well as a mixture of gas liquefied atmospheric gases, the nitrogen content of which is greater than the nitrogen content of the atmosphere. For example, the mixture has a nitrogen content of 90, preferably at least 99 mol%.

A "cold" liquid or a corresponding fluid, liquid air product, stream, etc., is taken to mean a liquid medium, the boiling point of which is significantly less than the respective ambient temperature, for example below 200 K, in particular below 220 K. Examples of cryogenic media in the sense above are liquid air, liquid oxygen and liquid nitrogen.

A "heat exchanger" may comprise two or more streams, such as a warm pressurized air stream and one or more cooling streams or a cold liquid air stream, And indirect movement of heat between one or more of the warming streams. The heat exchanger may be formed into a single heat exchanger section or a plurality of parallel and / or series connected heat exchanger sections, e.g., of one or more plate heat exchanger blocks. The heat exchanger, which is distinguished in that the main fraction of the streams to be cooled or warmed is thereby cooled or warmed, for example the "main heat exchanger" used in the air separation system also has "passages" And are configured as fluid channels separated and having heat exchanger surfaces. The corresponding heat exchangers have, on operation, the "warm side" and the "cold side", the temperatures of which are different. The "warm side" temperature of the heat exchanger is the temperature at which the streams to be cooled are transferred to the heat exchanger. Optionally, since the plurality of streams to be cooled are transferred to different heat levels in the heat exchanger, the heating side temperature may also be related to the average or minimum or maximum temperature of the streams to be cooled to be transported.

A "compressor" is a device configured to compress one or more gas streams at one or more final pressures, where the stream is removed from the compressor system, from one or more starting pressures where the stream is delivered to the compressor. The compressors may also include a plurality of "compressor stages" in the form of known pistons, screws, and / or paddle wheels and / or turbine arrangements (i.e., axial or radial compressor stages Lt; RTI ID = 0.0 > a < / RTI > structural unit. This also applies to the "main air compressor" of an air separation system which is distinguished in that all or a major fraction of the amount of air delivered into the air separation system is compressed by the main air compressor. In particular, these compressor stages are driven by a shared drive, for example via a shared shaft. A plurality of compressors, such as a main compressor and a booster of an air separation system, may be coupled to each other. The "booster" is configured for an additional pressure rise of the already pressurized stream. A "cold compressor" is distinguished in that the corresponding stream can be conveyed to it at low temperature, especially also at low temperature. The cooling compressor in this case is equipped according to the prior art.

An "expansion turbine," which may be coupled to energy converters such as additional expansion turbines or oil brakes, generators, or compressors via a shared shaft, At least a portion of the liquid stream. In particular, expansion turbines may be configured for use in the present invention as turbo expanders. If the compressor is driven by one or more expansion turbines but is operated without external energy, for example if supplied by an electric motor, the expression "turbine driven" Turbine driven compressors and arrangements of expansion turbines are also termed "booster turbines ". In the context of this application, a "pressurized nitrogen turbine" or "PGAN turbine" is termed an expansion turbine, in which the nitrogen-enriched pressurized stream produced in the air separation system and withdrawn from the distillation column system is expanded. The expansion pressurized stream may then be warmed in, for example, the main heat exchanger and blown off to ambient environments. An expansion turbine, designated as a "medium-pressure turbine ", is used in connection with three column systems specifically including a high pressure column, a medium pressure column and a low pressure column. The intermediate pressure turbine expands the pressurized air stream that is compressed by the main air compressor and optionally boosted in the booster, after cooling in the main heat exchanger into the medium pressure column. Conversely, a pressurized air stream, compressed by the main air compressor and selectively boosted in the booster, via the " injection turbine ", after cooling in the main heat exchanger, Lt; / RTI > Conversely, the stream that is expanded into the high pressure column by the expansion valve is termed a "throttled stream ". This stream is pre-compressed, for example, to a pressure level above the operating pressure of the high-pressure column by the booster in the main air compressor or downward of the main air compressor and / or by the turbine-driven compressor.

"Tank system" is taken to mean, in the context of the present application, an arrangement having one or more low temperature storage tanks that are equipped for storage of liquid air products. The corresponding tank system has insulating means.

The present application uses the expressions "pressure level" and "temperature level ", in order to characterize pressures and temperatures, It represents the fact that it does not need to be used in the form of values. However, these pressures and temperatures typically occur within defined ranges that are, for example, +/- 1%, 5%, 10%, 20%, or even 50%, an approximate average value. Corresponding pressure levels and temperature levels may be within disjoint ranges or within overlapping ranges. In particular, for example, the pressure levels include inevitable or expected pressure drops, for example due to cooling effects. This is applied corresponding to the temperature levels. Here, the pressure levels stated in bar units are absolute pressures.

Liquid air products or corresponding liquid streams can be converted to a gas or supercritical state by warming. When the warming progresses to a subcritical pressure, a regular phase shift by evaporation proceeds. However, if the liquid air products are warmed at a pressure above the critical pressure, as soon as the temperature rises above the critical temperature, the phase transition does not proceed in a practical sense, but the transition from the liquid state to the supercritical state proceeds. In the context of the present application, if the expression "evaporation" is used, it also includes movement from a liquid state to a supercritical state.

The invention proceeds from a method of manufacturing one or more air products in which an air separation system having a main air compressor, a main heat exchanger and a distillation column system is used. As already discussed in the introduction, the method includes in this case first and second modes of operation, wherein, in the first mode of operation, one or more liquid air products produced in the distillation column system are stored, (E.g., liquid air, liquid nitrogen, or liquid oxygen) stored in a first mode of operation and / or one or more additional liquid air products that are not manufactured in a second mode of operation (E.g., liquid air, liquid nitrogen or liquid oxygen), and / or externally transferred liquid air products and / or other ways are transferred into the distillation column system.

In accordance with the present invention, in a second operating mode, one or more gas pressurized streams at a temperature level that is less than the warm-side temperature of the main heat exchanger are delivered to the refrigerant compressor and the second atmospheric pressure excess pressure Level, and is delivered to the at least one distillation column of the distillation column system at a second atmospheric pressure excess pressure level. The distillation column operates at an operating pressure corresponding to a second atmospheric pressure excess pressure level. This approach presents significant advantages over the prior art.

As already mentioned previously, it is often readily possible to transfer a relatively small amount of cold liquids or liquid air products into the cooling box of an air separation system, which is inevitable due to insulation and losses in the (main) heat exchanger Due to incursion (warm-side temperature difference), a certain amount of cold air is always required. This amount of cold air is normally supplied by the expansion turbine used.

If the cold requirement is covered by a feed-in as previously described, the expansion machine may be switched off. If a so-called intermediate pressure turbine is used which expands the compressed air additionally, this enables a corresponding saving of the drive power in the main air compressor (connected downstream thereof) and / or the booster connected downstream thereof. If a corresponding method is realized on the basis of what is termed a jet turbine, this is similarly applied by expanding into a low pressure column of a distillation column system in which air is used. Switching off the turbine, as shown in the figures present in the context of this application, if used what is termed a pressurized nitrogen or PGAN turbine, is to be able to utilize the fact that a considerable available amount of pressurized nitrogen is available , From which the energy used for compression can be recovered. For this purpose, after the stream is heated in a heater upstream, the corresponding pressurized stream is conveyed and the pressurized stream is expanded to the pressure required for a particular area of use (e.g., for use as a regeneration gas) , An external expansion engine may be used.

If more cold air is introduced into the cooling box than required, over a relatively long period of time, by the feed-in of cold liquids or liquid air products, this will cause temperature profiles in the heat exchangers used to be inevitable Quot; shift "), so that the temperature of one or more of the streams coming out of the heat exchanger becomes increasingly lower. From a certain limit, the reliable or specified operating mode of the air separation system is no longer guaranteed. If the heat input into the cooling box is not increased by the additional heat source, then the additional feed-in is no longer possible afterwards. For this purpose, as mentioned, any known heat-producing apparatus may be used, such as air-heating, steam-heating, gas-heating heat exchangers or heat exchangers which are heated electrically or in some other way have.

In this connection, however, the use of cooling compressors (i.e., compressors having an inlet temperature lower than ambient temperature, as described above) proves to be particularly advantageous, whereby heat can be introduced into the system But because the entire method can be influenced and improved by the desired compression of particular material streams. The corresponding method is illustrated in Figures 1 and 2 which will be described later. Here, a corresponding expansion turbine (e.g., in a "second" operating mode, as implemented by the corresponding cold liquids or feed-in of liquid air products), as well as a pressurized nitrogen turbine, For example a jet turbine), the total amount of pressurized nitrogen is compressed in the refrigeration compressor, then warmed in the preheater and expanded in a separate (medium pressure) expansion turbine. However, the use of an external expansion turbine with a preheater upstream is not satisfactory in all cases, since these hardware components must be very expensive and must operate with considerable energy consumption. Thus, for example, a separate, separate steam system is provided to operate the corresponding preheater. The associated losses are large. Thus, methods and / or systems without such devices are particularly desirable and advantageous in terms of cost savings and energy savings.

The use of cooling compressors in air separation systems is known per se. For example, in US 7 272 954 B2, a refrigeration compressor is used to compress a throttled stream. However, such use contradicts the objections of the method and the corresponding system described herein: the throttled stream continues to perform the corresponding expansion into the high pressure column to produce additional cold air, as described To be precisely compressed. Thus, the throttled stream is compressed here to a higher atmospheric pressure excess pressure level, but is not transferred into this pressure column at this pressure and is again expanded again. In the context of the present invention, the first atmospheric pressure excess pressure level is also less than the operating pressure of the high pressure column.

In the already recited "first operating mode" of the corresponding air separation system, non-gaseous air products are provided, for example in oxyfuel or IGCC processes. The first mode of operation may also include withdrawing liquid air products from the corresponding system (during the stated low electrical or electrical residual times) and delivering them into the storage tanks provided for this purpose . The first mode of operation is distinguished primarily in that additional cold air is generated in the air separation system, for example by a pressurized nitrogen turbine, a jet turbine and / or a medium pressure turbine. In a first mode of operation, at any rate, small amounts of air products previously stored in the tank system are transferred into the used distillation column system and, as required, in such a manner that the mentioned adverse effects of over- Respectively.

Conversely, in the mentioned "second operating mode ", generally no additional cooling air is generated by the pressurized nitrogen turbine, the jet turbine and / or the intermediate pressure turbine, Column system, and, as required, are further separated. These air products may also be stored or provided by additional devices or systems, for example, into storage tanks by means of a separate gas liquefier. In the second mode of operation, the refrigeration compressor is used to ensure heat introduction and at the same time to perform compression of the corresponding pressurized stream.

Thus, the present invention provides an air separation system that enables particularly advantageous operation even in the case of relatively large amounts of feed-in of liquid air products, e.g., stored in storage tanks, using inexpensive means. Compared to air separation systems with heated heat exchangers, as well as systems with cooling compressors and external expansion turbines, costs can be significantly reduced.

Of course, the first mode of operation described above may also be included by way of which one or more and / or one or more additional gaseous pressurized streams are expanded to be cooled-manufactured in the expansion turbine. The method, if desired, is switched over between the two modes of operation here.

The method may advantageously be used when a distillation column system including a high pressure column and a low pressure column is used wherein the high pressure column is operated at a higher operating pressure than the low pressure column. Such distillation column systems (e.g., twin-column systems or systems with separate high pressure and low pressure columns) are generally known in the professional world. Thus, the method is suitable for retrofitting multiple existing air separation systems with corresponding distillation column systems.

In these distillation column systems, the first pressure level corresponds to the working pressure of the low pressure column, and / or the second pressure level corresponds to the working pressure of the high pressure column. The present invention enables delivery into the distillation column system by corresponding pressure rise and simultaneous metered cold introduction.

Certain advantages and much more flexible method procedures appear when a distillation column system is also used that also includes a medium pressure column operated at an operating pressure between the operating pressures of the high pressure column and the low pressure column.

Correspondingly, where the first pressure level may correspond to the operating pressure of the low pressure column and the second pressure level may correspond to the operating pressure of the medium pressure column or the high pressure column. Alternatively, the first pressure level may correspond to the operating pressure of the intermediate pressure column, and the second pressure level may correspond to the operating pressure of the high pressure column.

In all cases, the at least one gas pressurized stream may be formed of at least a portion of the stream withdrawn from the distillation column of the distillation column system, and the distillation column, i. E. The low pressure column or, if present, And is operated at a first pressure level as an operating pressure. After compression in the refrigeration compressor, one or more gaseous compressed streams are at least partially introduced into the distillation column (in the case of a withdrawal from the low-pressure column, thus a medium-pressure column or high-pressure column, Level. ≪ / RTI >

As an alternative, however, the at least one gas pressurized stream may be fed to at least a portion of the stream provided by the main air compressor and cooled by the main heat exchanger, i. E., The feed- Intermediate < / RTI > pressure stream ", a portion of which is intended and corresponding pressure. This gas pressurized stream, which is continuously pressurized in the cooling pressurizer, can then be transferred into a distillation column operated at a corresponding pressure level.

One or more gas pressurized streams may be combined with one or more additional streams at a second pressure level before the stream is transferred into each of the distillation columns. If this second pressure level corresponds, for example, to the operating pressure of the high pressure column, then the corresponding compressed gas pressurized stream is provided by the main air compressor at this second pressure level and the corresponding Is combined with a pressurized air stream.

If the compressed gas pressurized stream is not yet at a predetermined temperature, after compression in the refrigerated compressor, the at least one gas pressurized stream may be at least partially cooled in the main heat exchanger. This is also an advantageous means to offset negative changes in the temperature profiles of the main heat exchanger due to entry of the desired temperature, by transfer in liquid air products.

In this case, and in accordance with the requirements and as shown, for example, in Figures 9 and 10, the feed-in into the heat exchanger can be effected, especially with the effect of favorable cooling and / or temperature profiles Lt; / RTI > may be performed at any desired point, depending on where it is located. Thus, the at least one gas pressurized stream can be delivered to the main heat exchanger on the warm side after compression in the refrigeration compressor, or to an additional temperature level below the warm-side temperature of the main heat exchanger.

The method also presents advantages when a portion of the compressed gas pressurized stream compressed in the refrigeration compressor is warmed up in the main heat exchanger and / or at least partly discharged from the air separation system. The corresponding stream can be used as a regeneration gas for it, for example in a purifier with adsorber containers, and is available at particularly advantageous pressure and temperature levels.

With respect to the features and advantages of the air separation system according to the present invention, references to the described advantages can be likewise made. This air separation system is equipped for operation in the first operating mode and the second operating mode described with the main air compressor, the main heat exchanger and the distillation column system, wherein in the first operating mode, in the distillation column system Means provided for storing one or more liquid air products to be produced and for transferring in the second mode of operation one or more liquid air products stored in the first operating mode and / or one or more additional liquid air products into the distillation column system do. The corresponding means may comprise, for example, manual or automatic process control switching means. The air separation system has a refrigerant compressor. In addition, in the second operating mode, one or more gas pressurized streams at a temperature level that is less than the warm-side temperature of the main heat exchanger are delivered to the refrigeration compressor, and at a refrigerating compressor, from a first atmospheric pressure excess pressure level to a second atmospheric pressure excess pressure level Means are provided for compressing the stream and then at least partially transferring it into at least one distillation column of the distillation column system at a second atmospheric pressure excess pressure level.

Reference can also be made to the above description, with reference to the features and advantages of the method according to the invention and the device according to the invention for producing electrical energy. In particular, it may in this case be a oxy-fuel combustion or IGCC process, and / or a corresponding device.

The invention will be explained in more detail with reference to the accompanying drawings.
1 shows an air separation system that does not follow the present invention in a first mode of operation in the form of a schematic system diagram.
Fig. 2 shows an air separation system according to Fig. 1 of a second operating mode in the form of a schematic system diagram.
Figure 3 shows an air separation system according to an embodiment of the present invention in a second mode of operation in the form of a schematic system diagram.
Figure 4 shows an air separation system according to an embodiment of the present invention in a second mode of operation in the form of a schematic system diagram.
Figure 5 shows an air separation system in accordance with an embodiment of the present invention in a second mode of operation in the form of a schematic system diagram.
Figure 6 shows an air separation system in accordance with an embodiment of the present invention in a second mode of operation in the form of a schematic system diagram.
Figure 7 illustrates an air separation system in accordance with an embodiment of the present invention in a second mode of operation in the form of a schematic system diagram.
Figure 8 shows an air separation system in accordance with an embodiment of the present invention in a second mode of operation in the form of a schematic system diagram.
Figure 9 illustrates the possibility of arranging the cooling compressor in an air separation system according to an embodiment of the present invention in a second mode of operation in the form of a schematic subdiagram.
Figure 10 illustrates the possibility of arranging the cooling compressor in an air separation system according to an embodiment of the present invention in a second mode of operation in the form of a schematic subdiagram.

Comparable elements bear the same reference indications in the figures, and for clarity, the explanations are not repeated.

In Figures 1 to 10, these same operating systems are sometimes depicted in different operating modes and in the same manner in which the liquid and gas streams are directed through different system components, lt; RTI ID = 0.0 > inter alia < / RTI > corresponding lines. The valves in this case are not shown. However, the shut off lines are shown crossed through (-x-).

1 shows an air separation system 110 that does not obey the present invention in the form of a schematic system diagram. Air separation system 110 is shown in Figure 1, which is the first mode of operation in which significant quantities of liquid air products are collected from "external transfer sources ", for example in a storage tank or air gas liquefaction system Is not transported to these. The first mode of operation shown is for producing liquid air products, for example at low power or over power periods, where the liquid air products are stored in corresponding storage tanks and fed into the air separation system 110 Is provided for the second mode of operation shown for FIG. 2 for transport. Additional modes of operation may also include exclusive or major provisions for gaseous air products.

The air separation system 110 includes as main components a main air compressor 10, a main heat exchanger 20 and a high pressure column 31, a medium pressure column 32 and a low pressure Column includes a distillation column system 30 configured as a multicolumn system having a column and a low pressure column having a first section 38 and a second section 33. These two sections are defined by a gas line (k) which forms a single distillation space by means of which there is no pressure-changeable dimensions and which, for separation action, pressure and temperatures, can not be distinguished from one piece low- Lt; / RTI >

The operating pressure of the high pressure column 31 is, for example, 5.0 to 5.5 bar at the top and the operating pressure of the low pressure column 33 is, for example, 1.3 to 1.4 at the top. The operating pressure of the intermediate pressure column 32 is between the operating pressure of the high pressure column 31 and the operating pressure of the low pressure column 33.

The main air compressor 10 includes at least a first pressurized air stream and a second pressurized air stream l to provide distillation column system 30 and / or pressurized air corresponding to each of the columns. . The pressure level of the first pressurized air stream in this case is at the operating pressure of the high pressure column 31 (and is therefore also referred to as "high pressure air" (HPAIR)) and conversely, The pressure level of the air stream l is at the operating pressure of the medium pressure column 32 (hence also referred to as "medium-pressure air" (MPAIR)).

The provision of corresponding pressurized air streams a and 1 is generally known and is not described in detail here. For example, in the main air compressor 10, the atmosphere is taken up by suction through a filter and compressed to the pressures at multiple stages. The first pressurized air stream may be withdrawn, for example, at the end of multistage compression, and the second pressurized air stream l may be withdrawn at an intermediate location. After compression, the air can be cooled directly into the cooling water in the heat exchanger directly in the contact cooler. The cooling water may be transferred from an evaporative cooler and / or from an external transfer source. The compressed and cooled air can then be purified in a purifier. The purifier may have a pair of containers filled with a suitable sorbent material. For the regeneration of the purifier, a nitrogen-rich regeneration gas is used, here in the form of stream v, described hereafter.

In the illustrated example, the first pressurized air stream at the pressure level is directed through the passage 21 of the main heat exchanger 20 and is cooled there close to the dew point. A cooled pressurized air stream downstream of the main heat exchanger 20, designated as a, is delivered to the high pressure column 31, a portion of which is transferred to the high pressure column 31, And is gas-liquefied in an evaporator or a bath condenser (34). For the gas liquefied fraction, the fraction is transferred back into the liquid state in the intermediate pressure column 32, and additional fraction is led through the subcooler 35 and expanded into the low pressure column 33.

The second pressurized air stream l is partly directed through the passages 24 of the main heat exchanger 20 and is cooled there close to the dew point. Conversely, additional fractions are introduced through the heat-exchanger element 44 which can also be incorporated in the main heat exchanger 20 and used to vaporize the oxygen-enriched liquid stream n (see below). The combined fractions are then transferred into the intermediate pressure column 32.

From the sump of the high pressure column 31 and the intermediate pressure column 32 the oxygen-enriched liquid streams are taken off in each case and taken as stream h through the subcooler 35 And expanded into the low pressure column (33).

From the sump of the low pressure column, the oxygen-enriched liquid stream (i) is removed, boosted by the pump 36 and delivered into the evaporator 37 via the (unlabelled) expansion valve, (See below) to the first section 38 of the low pressure column and the low pressure column bottom evaporator 39 is arranged in the sump of this low pressure column. In the example, the two evaporative condensers, the low pressure column intermediate evaporator 37 and the low pressure column bottom evaporator 39 are configured as falling-film evaporators. The liquid and gaseous fractions obtained from the top of the oxygen column 38 are partially recycled into the low pressure column 33 as stream k. Another portion of the liquid flowing out of the evaporation space of the low pressure column middle evaporator 37 is applied to the first section 38 of the low pressure column as a reflux liquid.

From the sump of the low pressure column 38, the liquid oxygen-enriched stream is removed and transferred to a side condenser 34 which is configured as an evaporative condenser (bath evaporator) with a liquid bath. From the top of the side condenser 34 the gaseous oxygen-enriched stream m is removed and warmed in the main heat exchanger 20 to provide a gaseous oxygen pressurized product (here designated GOX) Lt; / RTI > From the sump of the side condenser 34 the liquid oxygen-enriched stream is removed and vaporized in the heat exchanger element 44 from where the substream n is boosted to the liquid state, Is used to provide the product. Conversely, the sub-stream o is used to provide a liquid oxygen-enriched air product (referred to herein as LOX) where the portion is subcooled and subcooled in the subcooler 35. The liquid air product may be transferred to and stored in a suitable storage tank (61).

From the top of the high pressure column 31, the nitrogen-rich gas stream p is removed and gas liquefied in a descent-epidermal evaporator or descending-epidermal condenser 39. The sub-stream is recycled to the high-pressure column 31 and an additional substream (see link A) is guided through the subcooler 35 and then into the low-pressure column 33.

From the top of the intermediate pressure column 32 the nitrogen-rich gas stream r is removed and partially gas liquefied in the descent-epidermal evaporator or descending-epidermal condenser 37. The sub-stream is recycled to the intermediate pressure column 32 and the additional substream s is introduced through the subcooler 35 and then partially expanded into the low pressure column 33 and the liquid nitrogen- rich air product (referred to herein as LIN). It may also be stored in a suitable storage tank 62.

The additional (larger) sub-stream t of stream r is bypassed and cooled in main heat exchanger 20 in the first operating mode shown. The fraction thereof, here illustrated as stream (u), may be withdrawn back to the intermediate temperature from the main heat exchanger 20 and thereafter cooled-down in a "cooling" expansion turbine 46 (designated a pressurized nitrogen turbine) It is expanded cold-producingly, and the turbine can be coupled to, for example, a generator. The unexpanded fraction in the expansion turbine 45 is provided in the form of a gaseous nitrogen-rich air product (here designated MPGAN). After expansion in the expansion turbine 45 the stream u is again directed from the cold end through the main heat exchanger 20 to the warm end and the substreams v on the warm side of the main heat exchanger 20 And w). Substream v is used as regeneration gas REGGAS in main air compressor 10 and / or a purifier is assigned to him (see above). Conversely, the sub-stream w is expanded in an additional expansion turbine 52, which can be warmed by the heat exchanger 51 operated by the hot water stream and then coupled to the generator as well.

From the top of the low pressure column 33, the nitrogen-enriched stream (y) is removed, warmed in the main heat exchanger 20 and passed out of the air separation system 110.

As already explained, the use of the expansion turbine 46 serves to carry a considerable amount of cold, which is always required due to inevitable heat transfer through insulation and through losses in the main heat exchanger (warm- Side temperature difference). If this cold air is already covered by the liquid air products being conveyed, as shown in the second operating mode of the air separation system 110 shown in FIG. 2, the expansion turbine 46 is shut off. In the example shown, this results in a usable large amount of the corresponding nitrogen-enriched air product available under pressure, from where energy can be restored. For example, in other configurations in which the pressurized stream that is "directly" provided by the main air compressor and that is cooled in the main heat exchanger is expanded within the corresponding expansion turbine (similar to the expansion turbine 46) The reduction in the driving power source in the main air compressor 10 can proceed.

In Fig. 2, a corresponding second operating mode of the air separation system 110 is shown. First, an oxygen-enriched liquid air product (LOX) is transferred from the storage tank 61 to the bath evaporator or to the bath condenser 34 (see link portion B) and secondly to the liquid air product liquid air product (for example, gas liquefied air from an external gasifier specified here as LAIR) is transferred from the additional storage tank 63 into the low pressure column 33. Thereby, the cooling requirement of the air separation system 110 is already covered beyond the requirement, so that the expansion turbine 46 can be shut off. Depending on the withdrawal rate of the gaseous nitrogen-enriched air product (MPGAN), which can be controlled by an unillustrated valve, therefore, a large amount of the corresponding nitrogen-enriched air product can be used, ) Is available under pressure from where energy can be recovered in the expansion turbine 52 and / or its generator. However, in this case, the air should be prewarmed. However, the use of corresponding sun-on devices is complicated.

The refrigeration compressor (45) also operates in a second operating mode. As similarly described, when more chilled air is introduced into the cold box of the air separation system 110 than is required for liquid air products (here LOX and LAIR) Quot; shifting ", and the temperature of one or more of the streams coming out of the heat exchangers will be gradually cooled. From a certain limit, the reliable operating mode of the air separation system will no longer be guaranteed. This problem is solved within the air separation system 110 by operating the cooling compressor 45 as a heat transfer source. Not only can the heat be introduced into the system through the refrigeration compressor 45, but also the entire method can be influenced by the targeted compression of specific material streams (here stream t) Which can be heated by other heat-producing devices, such as air-heated, steam-heated, gas-heated or electro-heated heat exchangers or heat exchangers heated in other manners It will not be possible. A pressure rise implemented by the cooling compressor (45) may be used in the expansion turbine (52).

A particular advantage of the air separation system not according to the invention of the drawing is that this occurs in the air separation system 110 according to the invention, which is illustrated and described hereinafter, in which the cooling compressor 45 Which is used as the feed compressor and is included in the distillation column system 30. In the second operating mode, in other words, the one or more gas pressurized streams (see continuous streams b to g) are cooled to a temperature level that is less than the warm-side temperature of the main heat exchanger 20, And is compressed in the refrigeration compressor 45 from a first atmospheric pressure level to a second atmospheric pressure excess pressure level and a second atmospheric pressure excess pressure level is passed through the one or more of the distillation column systems 30 Distillation columns 31 and 32, respectively. In other words, within the refrigeration compressor 45, for example, a corresponding gas pressurized stream e (e.g., air from the main air compressor 10 in the form of a stream as described below, The nitrogen-enriched gas pressurized stream from one of the distillation columns in the form of b, d, f and g) is fed to the low or medium pressure column 32 or 33, or to a column Pressure or high-pressure column 31 or 32, or a pressure level that is typically used for a column having a pressure higher than the operating pressure. After a corresponding cooling in the main heat exchanger 20 (if desired), the compressed stream is transferred into a corresponding distillation column 31, 32 at a suitable location

As in this case, especially for the methods, the two pressurized streams a and l are provided by the main compressor 10 at different pressure levels, which leads to the fact that rectification is improved do. In three-column systems, the fraction of air which will be introduced into the high-pressure column 31 and which will be introduced into the intermediate-pressure column and which is to be compressed beforehand under pressure, More. This result is that the total energy consumption of the corresponding air separation system 100 is significantly reduced. The cooling compressor 45 in this case is advantageously connected in this manner, in which the connections (ports) of the expansion engine 46, which are then shut off, are used. This significantly reduces the expenditure on the device and control technology.

FIG. 3 illustrates a corresponding air separation system 100 in accordance with an embodiment of the present invention in a second mode of operation. The first operating mode is not shown again, but corresponds fundamentally to that of FIG. 1: in the first operating mode, the corresponding stream is led through the expansion turbine 46 and the refrigerant compressor 45 is bypassed ( bypassed). 2, the oxygen-enriched liquid air product (LOX) is transferred from the storage tank 61 into the bath evaporator or bath condenser 34 (the link portion B) (For example, gas liquefied from an external gasifier, here designated LAIR) is transferred from the additional storage tank 63 into the low pressure column 33

The refrigerant compressor 45 is charged here with the substream b of the nitrogen-enriched stream y removed from the low pressure column 33, Atmospheric pressure excess pressure levels, for example 1.3 to 1.4 bar. In the refrigeration compressor 45, this sub-stream b has a higher ("second") atmospheric pressure excess pressure corresponding to the operating pressure of the intermediate pressure column 32, Level. The compressed substream (b) is then conveyed to the passages 25 of the main heat exchanger 20 at an intermediate temperature and cooled accordingly as described. After cooling, stream (b) is applied to the intermediate pressure column 32 at the top. Additional substreams j (MPGAN) and z (optionally only partially used as regeneration gas REGGAS in the first operating mode) may be vented from the air separation system as well, if desired. Heat exchanger 51, And the arrangement of the expansion turbine 52 are not used.

Figure 4 shows an additional air separation system according to an embodiment of the present invention in a second mode of operation. The refrigerant compressor 45 is also filled with a sub-stream of the nitrogen-enriched stream (y) which is here removed from the low pressure column 33 and is designated herein as c and the aforementioned atmospheric pressure excess pressure level of the low pressure column 33, Lt; RTI ID = 0.0 > 1.3 < / RTI > In the refrigeration compressor 45, this sub-stream c is discharged from the above ("first") atmospheric pressure excess pressure level, but at a higher ("second") atmospheric pressure corresponding to the operating pressure of the high pressure column 31 And is compressed to an excess pressure level. The compressed substream c, as described, is then transferred to the passages 27 of the main heat exchanger 20 at an intermediate temperature and cooled accordingly. After cooling, stream c is applied to the high pressure column 31 at the top. Additional streams j (MPGAN) and z (optionally only used as regeneration gas REGGAS in the first operating mode) and also a nitrogen-enriched high pressure stream (HPGAN), if desired, Can pass.

Figure 5 illustrates an additional air separation system in accordance with an embodiment of the present invention in a second mode of operation. The refrigeration compressor 45 is then filled with the stream d drawn from the intermediate pressure column 32 from above and is thus available at the above mentioned atmospheric pressure excess pressure level at the top of the intermediate pressure column 32 and at the temperature level thereof have. In the refrigeration compressor 45 this sub-stream d is withdrawn from the above ("first") atmospheric pressure excess pressure level, where the higher ("second") atmospheric pressure, again corresponding to the operating pressure of the high pressure column 31 And is compressed to an excess pressure level. The compressed substream d, as described, is then transferred to the corresponding passages 27 of the main heat exchanger 20 at an intermediate temperature and cooled accordingly. After cooling, stream (d) is applied to the high pressure column 31 at the top. Additional streams j (MPGAN) and z (which are selectively used as regeneration gas REGGAS in only a first mode of operation) and also a nitrogen-rich high-pressure stream (HPGAN) As may be required from an air separation system.

Figure 6 illustrates an additional air separation system in accordance with an embodiment of the present invention in a second mode of operation. The refrigerant compressor 45 is now filled with a sub-stream e of the pressurized stream l from the main air compressor 10, which is at the above-mentioned atmospheric pressure excess pressure level corresponding to the operating pressure of the intermediate pressure column 32. Substream e is removed from the main heat exchanger 20 at the cold end in this manner, whose temperature level is below the warm-side temperature level of the main heat exchanger 20. In the refrigeration compressor 45 this sub-stream e has a higher ("first") atmospheric pressure excess pressure level, where it corresponds to the higher operating pressure of the high pressure column 31, 2 ") is compressed to an atmospheric pressure excess pressure level. The substream e to be compressed as described is then transferred to the passage 21 of the main heat exchanger 20 at an intermediate temperature and thereby combined with the stream a. Where the stream specified additionally is cooled accordingly. After cooling, stream (a) is conveyed into high pressure column 31. The additional streams j (MPGAN) and z (selectively used as regeneration gas REGGAS in only a first operating mode), as above, can also be passed as required from the air separation system.

Figure 7 illustrates an additional air separation system in accordance with an embodiment of the present invention in a second mode of operation. The cooling compressor 45 here is filled with the stream f drawn out from the low pressure column 33 and is therefore present at the atmospheric pressure excess pressure level of the low pressure column 33 described above, for example 1.3 to 1.4, exist. In the refrigeration compressor 45, this sub-stream f has a higher ("second") atmospheric pressure exceeding the atmospheric pressure excess pressure level here ("first") eventually corresponding to the operating pressure of the intermediate pressure column 32 Compressed to a pressure level. The substream f which is compressed as described is then transferred to the passage 24 of the main heat exchanger 20 at an intermediate temperature and thereby combined with the stream l. Where the stream specified in addition l is correspondingly cooled. After cooling, the stream (l) is transferred into the intermediate pressure column (32). Additional streams j (MPGAN) and z (optionally only used as regeneration gas REGGAS in a first mode of operation) may be passed out of the air separation system, as also required, as above.

Figure 8 illustrates an additional air separation system in accordance with an embodiment of the present invention in a second mode of operation. The cooling compressor 45 is here also filled with the stream g drawn out of the low pressure column 33 and thus is present at atmospheric pressure excess pressure level of the low pressure column 33 mentioned above, for example 1.3 to 1.4, Lt; / RTI > In the refrigeration compressor 45 this sub-stream g is withdrawn from the above ("first") atmospheric pressure excess pressure level, where the higher ("second") atmospheric pressure which eventually corresponds to the operating pressure of the high pressure column 31 For example, from 5.0 to 5.5 bar. The substream g compressed as described is then transferred to the passage 21 of the main heat exchanger 20 at an intermediate temperature and thereby combined with the stream a. Where the stream specified additionally is cooled accordingly. After cooling, the stream (a) is transferred into the high pressure column 31 in particular. Additional streams j (MPGAN) and z (optionally only used as regeneration gas REGGAS in a first mode of operation) may also go out of the air separation system as required.

9 and 10 illustrate alternative possibilities for arranging the cooling compressor 45 in a schematic partial depiction. No reference indications are provided for the corresponding streams again. These possibilities are achieved in all of the systems shown in Figures 3-8 and in additional embodiments of the invention not shown.

According to Fig. 9, the stream compressed by the cooling compressor 45 is transferred to the main heat exchanger 20 on the warm side. According to Fig. 10, the stream is withdrawn from the main heat exchanger 20 to the first intermediate temperature, then compressed, and then back to the main heat exchanger 20 to the second intermediate temperature.

Claims (14)

A method of making at least one air product,
The air separation system 100 includes a main air compressor 10, a main heat exchanger 20 and a high pressure column 31, a medium pressure column 32, The high pressure column 31 has a distillation column system 30 including a column 33, a low pressure column sump evaporator 39 and a low pressure column intermediate evaporator 37, Pressure column 33 and the intermediate pressure column 32 operates at an operating pressure that is between the operating pressures of the high pressure column 31 and the intermediate pressure column 33 and the low pressure column sump evaporator 39 ) And the low-pressure column intermediate evaporator 37 are constructed as evaporative condensers,
The method includes a first and a second operating mode,
In the first operating mode, one or more liquid air products (LIN, LOX) produced in the distillation column system 30 are stored,
- in the second operating mode,
(LIN, LOX, LAIR) and / or one or more additional liquid air products (LIN, LOX, LAIR) stored in the first operating mode are transferred into the distillation column system 30,
One or more gas pressurized streams b to g that are below the warm side temperature of the main heat exchanger 20 are delivered to the refrigeration compressor 45 and the first superatmospheric pressure level pressure level to a second atmospheric pressure excess pressure level and is at least partially conveyed to a second pressure level into one or more distillation columns (31, 32) of the distillation column system (30).
A method of making at least one air product.
The method according to claim 1,
Characterized in that, in the first operating mode, at least one pressurized stream and / or at least one additional gas pressurized stream (b to g) is expanded to be cooled and manufactured in an expansion turbine (46)
A method of making at least one air product.
3. The method according to claim 1 or 2,
Characterized in that the oxygen-enriched stream from the sump of the low-pressure columns (33, 38) is vaporized in a side condenser (34) to provide a gaseous oxygen pressurized product (GOX) and the side condenser (34) is configured as an evaporative condenser ,
A method of making at least one air product.
4. The method according to any one of claims 1 to 3,
Characterized in that the first pressure level corresponds to the working pressure of the low pressure column (33) and / or the second pressure level corresponds to the working pressure of the high pressure column (31)
A method of making at least one air product.
5. The method according to any one of claims 1 to 4,
The first pressure level corresponds to the operating pressure of the low pressure column 33 and the second pressure level corresponds to the operating level of the intermediate pressure column 32 or the high pressure column 31 or the first pressure level corresponds to the operating pressure of the intermediate pressure column 32 , And the second pressure level corresponds to the operating pressure of the high-pressure column (31).
A method of making at least one air product.
6. The method according to any one of claims 1 to 5,
The at least one gas pressurized stream (b, d, f, g) is formed from at least a portion of the stream withdrawn from the distillation columns 32, 33 of the distillation column system 30, Lt; RTI ID = 0.0 >
A method of making at least one air product.
7. The method according to any one of claims 1 to 6,
Characterized in that the at least one gas pressurized stream (e) is formed by at least a portion of the stream provided by the main air compressor (10) and cooled by the main heat exchanger (20)
A method of making at least one air product.
8. The method according to any one of claims 1 to 7,
The at least one gas pressurized stream (e) is combined with the at least one additional stream (a) to a second pressure level before the gas pressurized stream is transferred into the at least one distillation column (31, 32) of the distillation column system (30) ≪ / RTI >
A method of making at least one air product.
9. The method according to any one of claims 1 to 8,
Characterized in that the one or more gas pressurized streams (a to g) are at least partially cooled in the main heat exchanger (20) after compression in the cooling compressor (45)
A method of making at least one air product.
10. The method of claim 9,
One or more gas pressurized streams (a to g) may be delivered to the main heat exchanger 20 on the warm side for cooling after compression in the refrigeration compressor 45 or may be delivered to the main heat exchanger 20 Lt; RTI ID = 0.0 > a < / RTI > additional temperature level,
A method of making at least one air product.
11. The method according to any one of claims 1 to 10,
Characterized in that a portion of the compressed gas pressurized streams (a to g) compressed in the refrigeration compressor (45) is warmed in the main heat exchanger (20) and / or at least partially discharged from the air separation system (100)
A method of making at least one air product.
1. An air separation system (100) comprising a main air compressor (10), a main heat exchanger (20), and a distillation column system (30) and equipped for operation in first and second operating modes,
In a first mode of operation, one or more liquid air products (LIN, LOX) to be produced in the distillation column system 30 are stored and in a second mode of operation, one or more liquid air products Means 61, 63 are provided for transferring one or more additional liquid air products (LIN, LOX, LAIR) and / or one or more additional liquid air products (LIN, LOX, LAIR) into the distillation column system 30,
The air separation plant 100 comprises a refrigeration compressor and in a second mode of operation one or more gas pressurized streams (b to g) at a temperature level that is less than the warm side temperature of the main heat exchanger (20) (45), compressing the stream in the refrigeration compressor (45) from a first atmospheric pressure excess pressure level to a second atmospheric pressure excess pressure level, and thereafter feeding the stream at a second pressure level at least partially to a distillation column system (31, 32) of the distillation column (30).
Air separation system.
A method for manufacturing electrical energy,
Characterized in that at least one air product is provided by the method according to any one of claims 1 to 11 for at least a second mode of operation and is used for producing and /
Method of manufacturing electrical energy.
15. A system adapted to carry out the method according to claim 13,
Characterized in that it is equipped to carry out a process, in particular in combination with an oxyfuel process and / or an integrated gasification process.
system.

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