Energy recovery methods

Abstract

The present invention is a method for energy recovery comprising the steps of: a) providing a hot fluid stream; and b) thermally contacting the hot fluid stream with an aqueous condensate in a heat exchanger, thereby transferring heat from the hot fluid stream to the aqueous condensate and vaporizing at least a portion of the aqueous condensate to a temperature T 1 and pressure p 1 and c) subjecting the water vapor stream to at least one compression step to a pressure p 2 and d) using the compressed water vapor stream for energy recovery, thereby obtaining a stream comprising an aqueous condensate, 1 Pressure on p 2 The ratio of p 2 / p 1 , is 5 to 50; and an energy recovery facility, 1 and pressure p 1 A water vapor stream having a pressure p 2 and one or more means for compressing the water vapor stream, connected in series, at a temperature T 1 and pressure p 1 The steam stream having a pressure p 2 and the use in said method or installation for obtaining a compressed water vapor stream having

Description

[Technical Field]

[0001] The present invention relates to an energy recovery method in which thermal energy is transferred from a high-temperature fluid stream to an aqueous condensate in a heat exchange process, thereby obtaining a water vapor stream, which is then subjected to at least one heating and compression process, from which the heated and compressed water vapor stream is obtained for energy recovery. [Background technology]

[0002] In relation to efforts to reduce carbon dioxide emissions, one task is to reduce the consumption of carbonaceous primary energy. This has also led to a focus on recovering energy in the form of heated or compressed fluids, which can be used as an energy source in industrial processes, for example.

[0003] Chemical manufacturing processes, such as those for polymer polymerization, often consume significant amounts of thermal or electrical energy, for example, to heat or boil a stream to the temperature and pressure required for use or reuse, or to supply energy to the manufacturing equipment in the chemical manufacturing process. On the other hand, a large amount of waste heat is generated, for example, by cooling the product stream. However, most of these cooling streams are too low in temperature to be directly reused as a heating medium or for generating electrical energy. As an example, well-established licensed multi-step polymerization processes for polymerizing polyolefins include, among others, Borstar® from Borealis AG or Spheripol® from LyondellBasell. In these processes, two or more polymerization steps are connected in series, followed by downstream processes for processing the polymerized polyolefins. Waste heat is obtained from the cooling of the product stream in each of the polymerization steps and downstream processes, but this is currently largely wasted.

[0004] International Publication No. 2009 / 010514A1 and International Publication No. 2011 / 000925A1 disclose a method for recovering heat from a cooling fluid used to cool a polymerization reaction in a loop reactor by transferring thermal energy from the cooling fluid to the working fluid in a single heat exchange step, wherein the working fluid is phase-converted, thereby returning energy in the form of heat and / or power and / or thermal output to the polymerization process. However, these methods are adapted only to polymerization processes in loop reactors and require several intermediate streams for transferring thermal energy, which inevitably results in energy loss and reduced efficiency. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2009 / 010514A1 Pamphlet [Patent Document 2] International Publication No. 2011 / 000925A1 Pamphlet [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, there is a need for highly efficient energy recovery methods that can be applied to all types of waste heat generated, not only in industrial processes but also in other situations where waste heat is generated, such as power generation, engines, electronic equipment, or housings.

[0007] Surprisingly, it has been found that when heat is transferred from a high-temperature fluid stream from any heat source to an aqueous condensate, thereby obtaining a steam stream, this steam stream can be efficiently subjected to one or more heating and compression steps to generate a heated and compressed steam stream having a temperature and pressure suitable for direct use as a heating medium in energy recovery. [Means for solving the problem]

[0008] The present invention is an energy recovery method, a) A step of supplying a high-temperature fluid stream, b) A step of bringing the high-temperature fluid stream into thermal contact with the aqueous condensate in a heat exchanger, thereby transferring heat from the high-temperature fluid stream to the aqueous condensate and vaporizing at least a portion of the aqueous condensate to obtain a water vapor stream having a temperature T1 and a pressure p1, c) A step of subjecting the steam stream to at least one compression step to obtain a compressed steam stream having a pressure p2, d) A step of using the compressed water vapor stream for energy recovery, thereby obtaining a stream containing aqueous condensate. Includes, The ratio of pressure p2 to pressure p1, p2 / p1, is between 5 and 50. Regarding the method.

[0009] Furthermore, the present invention relates to equipment for energy recovery, A heat exchanger for transferring heat from a high-temperature fluid stream to an aqueous condensate to obtain a steam stream having temperature T1 and pressure p1, Means for compressing one or more, preferably 1 to 5, more preferably 2 to 4, most preferably 2 or 3, water vapor streams having temperature T1 and pressure p1, connected in series, to obtain a compressed water vapor stream having temperature T2 and pressure p2, preferably at least one, for example, one or two, preferably one heat pump compressor, each heat pump compressor comprising one or more, preferably 1 to 5, more preferably 2 to 4, most preferably 2 or 3 compression stages connected in series, and A means for using the compressed water vapor stream having pressure p2 for energy recovery, thereby obtaining a stream containing aqueous condensate, • A first means for transporting the steam stream from the heat exchanger to means for compressing the steam stream, Optionally, means for transporting the compressed water vapor stream from one upstream means for compressing the water vapor stream to the next downstream means for compressing the water vapor stream, among the series of means for compressing the water vapor stream. - Means for transporting the compressed water vapor stream having pressure p2 from the last of the series of means for compressing the water vapor stream to means for using the compressed water vapor stream having pressure p2 for energy recovery. Regarding equipment including...

[0010] Furthermore, the present invention relates to the use of means for compressing a water vapor stream, preferably one to five, more preferably two to four, most preferably two or three, connected in series, preferably at least one, for example one or two, preferably one heat pump compressor, each heat pump compressor comprising one to five, more preferably two to four, most preferably two or three compression stages, connected in series, in both of the above or below methods or manufacturing equipment for compressing a water vapor stream having a temperature T1 and pressure p1 to obtain a compressed water vapor stream having a pressure p2 for direct energy recovery.

[0011] In the sense of the present invention, "direct use" or "direct energy recovery" means that the compressed steam stream is used as an energy source, such as a heating source. This allows the compressed steam stream to be used as an energy source without further manipulation of its temperature and / or pressure. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows a schematic diagram of a conventional heat recovery step from a fluidized bed gas-phase reactor in which heat is transferred from the circulating gas stream to the working fluid during the heat exchange process. The heat from the working fluid is used to vaporize the aqueous condensate to obtain a water vapor stream for further use in the polymerization process. [Figure 2] Figure 2 shows a schematic diagram of one embodiment of the method of the present invention in which heat is transferred from a high-temperature fluid stream to an aqueous condensate, which vaporizes to produce a water vapor stream. This water vapor stream is subjected to several subsequent compression steps to obtain a compressed water vapor stream having a temperature and pressure range that allows for the direct use of the compressed water vapor stream in energy recovery. After use in energy recovery, the condensed water vapor stream is reused for heat transfer. [Figure 3]Figure 3 shows a schematic diagram of another embodiment of the method of the present invention in which the condensed water vapor stream after use in energy recovery is flashed, thereby reducing the pressure of the condensed water vapor stream. The flashed condensate stream is separated into a second water vapor stream and an aqueous condensate. The aqueous condensate is reused for heat transfer, while the second water vapor stream is combined with the compressed water vapor stream during a subsequent compression step. [Figure 4] Figure 4 shows a proposed example of the embodiment of Figure 2. This proposed example is further discussed below in the Examples section. [Figure 5] Figure 5 shows a proposed example of the embodiment of Figure 3. This proposed example is further discussed below in the Examples section. **DETAILED DESCRIPTION OF THE INVENTION**

[0013] Method In a first aspect, the present invention is an energy recovery method comprising: a) supplying a high-temperature fluid stream; b) thermally contacting the high-temperature fluid stream with an aqueous condensate in a heat exchanger, thereby transferring heat from the high-temperature fluid stream to the aqueous condensate and vaporizing at least a portion of the aqueous condensate to obtain a water vapor stream having a temperature T1 and a pressure p1; c) subjecting the water vapor stream to at least one compression step to obtain a compressed water vapor stream having a pressure p2; d) using the compressed water vapor stream for energy recovery, thereby obtaining a stream containing an aqueous condensate and · the ratio of the pressure p2 to the pressure p1, p2 / p1, is 5 to 50 relates to a method.

[0014] The high-temperature fluid stream preferably has a temperature T of 20 to 150 °C, more preferably 25 to 130 °C, and most preferably 30 to 110 °C. f and has. Therefore, the method of the present invention can also be used to recover energy from a fluid stream having a moderate temperature. Hence, in this context, the term "high temperature" refers to the temperature of the high-temperature fluid stream T such that heat can be exchanged from the high-temperature fluid stream to the first heat transfer fluid. f This simply means that the temperature is higher than the temperature T0 of the first heat transfer fluid before it enters the first heat exchanger.

[0015] High-temperature fluid streams can be supplied from any type of fluid stream at high temperatures. The source of the high-temperature fluid stream can be an industrial process, or any other situation of any kind in which waste heat is generated in the form of a high-temperature fluid stream, such as in power generation, engines, electronic equipment or housings.

[0016] In one preferred embodiment, the high-temperature fluid stream is supplied from an industrial process, more preferably from a chemical manufacturing process. A chemical manufacturing process is any process for producing a chemical product that can recover heat from a high-temperature fluid stream. In one particular embodiment, the chemical manufacturing process is a polymerization process. The polymerization process is preferably a process for polymerizing an α-olefin polymer. The polymerization process is preferably a low-pressure process for polymerizing an α-olefin polymer in the presence of a polymerization catalyst.

[0017] The polymerization catalyst can be any suitable catalyst for polymerizing the α-olefin polymer, such as a supported or unsupported Ziegler-Natta catalyst or a metallocene catalyst.

[0018] The α-olefin polymer may be a homopolymer or copolymer of ethylene and / or α-olefin monomers having 3 to 12 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, or 1-octene. Preferred are ethylene homopolymers, or copolymers of ethylene with one or more α-olefin comonomers having 3 to 12 carbon atoms, such as propylene, 1-butene, 1-hexene and / or 1-octene; and propylene homopolymers, or copolymers of propylene with ethylene or one or more α-olefin comonomers having 4 to 12 carbon atoms, such as ethylene, 1-butene, 1-hexene and / or 1-octene.

[0019] The polymerization process may be a one-step polymerization process or a multi-step polymerization process. In a one-step polymerization process, polymer polymerization is carried out in a single polymerization reactor, which can be selected from a slurry-phase reactor, such as a loop reactor, and a gas-phase reactor, such as a fluidized-bed gas-phase reactor. The polymerization process is preferably a multi-stage polymerization process in which two or more reactors, preferably two to six reactors, for example two, three, four, five, or six reactors, are connected in series. These two or more reactors are usually selected from slurry phase reactors, such as loop reactors, and gas phase reactors, such as fluidized bed gas phase reactors. Downstream of the reactor stage(s) of the polymerization process, the polymer is further processed. In this downstream processing stage, the polymer is preferably separated from unreacted monomers and other components of the production stream. Furthermore, the polymer is preferably compounded in an extruder with applicable additives, as known in the art.

[0020] Typical multi-step polymerization processes to which the method of the present invention can be applied include, among others, Borstar® PE and Borstar® PP from Borealis AG or Spheripol® from LyondellBasell.

[0021] High-temperature fluid streams can be provided from any process stage of a chemical manufacturing process, for example, one or more or all manufacturing stages in which a chemical product or any precursor or intermediate is produced, and / or from downstream processing stages from the manufacturing stage(s), such as a purification stage or a compounding stage.

[0022] It is particularly preferable that the high-temperature fluid stream is not a cooling stream from the heat exchange process. Alternatively, the high-temperature fluid stream is preferably a stream obtained directly without indirect heat exchange or energy transfer.

[0023] The high-temperature fluid stream may be a slurry stream, a liquid stream, or a gaseous stream. If it is a slurry stream or liquid stream, the high-temperature fluid stream is preferably at a temperature range of 20-120°C, more preferably 25-110°C, and most preferably 30-100°C. f It holds. If it is a gaseous stream, the high-temperature fluid stream is preferably in the range of 50-150°C, preferably 55-130°C, and most preferably 65-110°C. f The pressure is in the range of 5 to 50 bar, preferably 8 to 40 bar, and most preferably 10 to 35 bar.

[0024] In embodiments of the chemical manufacturing process, the high-temperature fluid stream is preferably a high-temperature product stream. In the embodiments of the polymerization process described above, the high-temperature product stream is preferably selected from a high-temperature polymer slurry stream from the slurry phase polymerization stage, a high-temperature circulating gas stream from the gas phase polymerization stage, or a high-temperature polymer stream from a downstream processing stage from the polymerization stage(s), such as the extrusion stage. The high-temperature fluid stream can also be the primary water circuit of an extruder in the processing stages downstream from the polymerization stage, for example, from the extrusion stage.

[0025] The high-temperature fluid stream provided from the polymerization process preferably comprises monomers, optionally comonomers (both defined above), and optionally a chain transfer agent, such as hydrogen. When the high-temperature fluid stream is a high-temperature polymer slurry stream from a slurry phase polymerization stage or a high-temperature polymer stream from a processing stage downstream from the polymerization stage(s)., the high-temperature fluid stream preferably contains polymer.

[0026] The high-temperature fluid stream is preferably transported directly to the heat exchange process. In this context, "directly" means that the high-temperature fluid stream does not undergo any further processing that would manipulate the temperature of the high-temperature fluid stream.

[0027] In a heat exchanger, a high-temperature fluid stream is brought into thermal contact with aqueous condensate. This transfers heat from the high-temperature fluid stream to the aqueous condensate, heating the aqueous condensate and temperature T f1 A fluid stream with a defined shape is obtained.

[0028] T f1 The temperature T of the high-temperature fluid stream is f It is lower than that. T f1 The temperature is preferably in the range of 15 to 145°C, more preferably 20 to 125°C, and even more preferably 25 to 98°C.

[0029] The aqueous condensate is preferably liquid water such as tap water. The aqueous condensate is preferably used only when it is used as a heating / cooling medium and in a closed energy recovery cycle used to generate electrical energy. It is preferable that the aqueous condensate is not separated from the product stream of the industrial production process, or not introduced into the product stream of the industrial production process.

[0030] When introduced into the heat exchanger, the aqueous condensate is preferably at least partially liquid, for example at least 60% by weight is liquid, preferably at least 75% by weight is liquid, most preferably at least 90% by weight is liquid. Thus, the non-liquid portion of the aqueous condensate is gaseous up to 40% by weight, preferably up to 25% by weight, most preferably up to 10% by weight. In a preferred embodiment, the aqueous condensate is 100% liquid depending on the temperature and pressure conditions when introduced into the heat exchanger.

[0031] When introduced into the heat exchanger, the aqueous condensate preferably has a temperature T of 40°C to 99°C, preferably 50°C to 98°C, most preferably 55°C to 95°C c and / or a pressure p of 1 to 10 bar (a), preferably 2 to 9 bar (a), most preferably 3 to 8 bar (a). c It has.

[0032] During heat transfer, the heated aqueous condensate is preferably at least partially vaporized so as to obtain a water vapor stream having a temperature T1 and a pressure p1. In some embodiments, the heated aqueous condensate is completely vaporized. If the heated aqueous condensate is only partially vaporized, the remaining aqueous condensate may be separated from the water vapor stream and recycled to the heat exchanger as aqueous condensate. The aqueous condensate can also be removed from the bottom of the heat exchanger to remove unwanted components such as salts, heavier components, rust, or other dirt from the heat exchanger.

[0033] The water vapor stream preferably has a temperature T1 in the range of 30°C to 150°C, preferably 40°C to 135°C, most preferably 50°C to 100°C and / or a pressure p1 in the range of 0.04 bar (a) to 4.76 bar (a), preferably 0.07 to 3.13 bar (a), most preferably 0.12 to 1.01 bar (a). For example, for direct use as a heat source or for generating electrical energy, the temperature T1 and pressure p1 of the water vapor stream are usually too low for efficient energy recovery to be possible. Therefore, in the method of the present invention, the pressure of the water vapor stream is increased to pressure p2.

[0034] To increase the pressure of the steam stream, the steam stream is subjected to at least one, for example, one to five, preferably two to four, most preferably two or three compression steps to obtain a heated and compressed steam stream having a temperature T2 and a pressure p2.

[0035] For the compression step(s), preferably at least one, for example, one or two, preferably one heat pump compressor is used. Each heat pump compressor preferably includes at least one, preferably one to five, more preferably two to four, and most preferably two to three compression stages connected in series. At least one heat pump compressor is preferably part of a heat pump as known in the art.

[0036] When multiple compression steps are used, the compression steps are preferably arranged in sequence by using one or more heat pump compressors, and at least one, preferably one to five, more preferably two to four, and most preferably two or three compression stages are arranged in sequence. In a continuous configuration, the steam stream is first subjected to a first compression step, preferably in the first upstream compression step of the heat pump compressor, thereby increasing the pressure of the steam stream by a first increment in the first step. The steam stream compressed in the first step is then subjected to a next downstream compression step, preferably in the second compression step of the heat pump compressor located downstream from the first upstream compression step of the heat pump exchanger, thereby increasing the pressure of the steam stream by a second increment in the second step. This is optionally repeated until a compressed first heat transfer fluid with pressure p2 is obtained in the final downstream heat exchange step, preferably in the final downstream compression step of the heat pump compressor.

[0037] During at least one, for example 1 to 5, preferably 2 to 4, most preferably 2 to 3, compression steps as described above, the temperature of the water vapor stream is raised to temperature T2. When multiple compression steps are used, the temperature of the water vapor stream typically increases incrementally during each compression step, in parallel with the incremental pressure increase as discussed above.

[0038] During at least one, for example, 1 to 5, preferably 2 to 4, most preferably 2 or 3, compression steps as described above, the temperature of the water vapor stream is preferably raised to temperature T2. When multiple compression steps are used, the temperature of the water vapor stream is typically increased incrementally during each compression step, in parallel with the increments of pressure increase as discussed above.

[0039] The increments in temperature and pressure during the subsequent compression process typically depend on the volume stream of the steam stream and the dimensions and output of each heat pump compressor. p in each compression process out / p in The increment of the pressure increase, determined as the ratio, is preferably in the range of 1.3 to 3, more preferably 1.5 to 2.5, independently. Preferably, the temperature rise in each compression step is independently in the range of 25 to 250 K, preferably 50 to 200 K.

[0040] In some embodiments, the temperature rise during the compression process can result in a temperature of approximately 300°C in the compressed water vapor stream. Temperatures exceeding 300°C are undesirable due to the potential for material fragility or failure of the affected pipes, armature, and mounting components. Therefore, it is preferable that the temperature of the compressed water vapor stream be reduced after one or more compression steps, preferably after each compression step, so that the temperature of the compressed water vapor stream does not exceed 300°C.

[0041] The temperature of the compressed water vapor stream can be reduced after one or more heating and compression steps, preferably after each heating and compression step, by combining the compressed water vapor stream with a higher-pressure aqueous condensate and a portion of the aqueous condensate from step d). The compressed water vapor stream is preferably combined with a higher-pressure aqueous condensate in a superheat reducer.

[0042] The amount of the compression step is preferably proposed by taking into account the expected pressure increase in each compression step in order to obtain a compressed steam stream having a pressure p2.

[0043] A compressed water vapor stream having a pressure p2 preferably has a temperature T2. Preferably, the temperature T2 is in the range of 125°C to 300°C, preferably 135°C to 275°C, most preferably 140°C to 250°C, and / or the pressure p2 is in the range of 3 bar(a) to 12 bar(a), preferably 4 to 10 bar(a), most preferably 5 to 8 bar(a).

[0044] Temperature T2 is preferably 50K to 250K, more preferably 65K to 150K, and most preferably 75K to 125K higher than temperature T1.

[0045] The ratio of pressure p2 to pressure p1, p2 / p1, is 5 to 50, preferably 10 to 40, and most preferably 15 to 30.

[0046] A compressed water vapor stream with pressure p2 is used for energy recovery.

[0047] One suitable method of energy recovery is to use a compressed steam stream as a heating medium. In manufacturing equipment, a steam stream can be used as a heating medium to heat, for example, a product stream, any other stream, or a part of the components of the manufacturing site, at any stage of the chemical manufacturing process, or even in the heating system of the manufacturing equipment. Preferably, in polymerization processes as discussed above, the compressed steam stream can be used, for example, to replace the steam in the reboiler in a step to recover monomers, comonomers and other reactants in the polymerization process, or to heat the flash tank in the gas-phase polymerization stage. A suitable method for storing thermal energy is one that uses a reverse condensation reaction, such as a chemical heat pump, which has been commercialized by Qpinch and is described, for example, in International Publication No. 2014 / 016405A1. A suitable method for generating electricity has been commercialized by Climeon and is described, for example, in particular in European Patent Application Publication No. 2689111A1. For example, excess compressed steam streams not used for energy recovery within an industrial process can be used as a heating medium or other form of energy recovery outside of the industrial process.

[0048] By using a compressed steam stream with pressure p2 for energy recovery, the temperature and pressure of the compressed steam stream are reduced to such an extent that the steam stream condenses at least partially, resulting in a stream containing aqueous condensate.

[0049] The stream containing the aqueous condensate is preferably at least partially liquid after being used for energy recovery, for example, at least 60% by weight liquid, preferably at least 75% by weight liquid, and most preferably at least 90% by weight liquid. This means that the non-liquid portion of the aqueous condensate is gaseous up to 40% by weight, preferably up to 25% by weight, and most preferably up to 10% by weight. In some embodiments, the aqueous condensate is 100% by weight liquid, depending on the temperature and pressure conditions after energy recovery.

[0050] Preferably, a stream containing aqueous condensate obtained from the compressed steam stream used for heat recovery is subjected to a steam separation process to obtain a second steam stream and aqueous condensate. Aqueous condensates can be used in a heat exchanger to transfer heat from a high-temperature fluid stream to the aqueous condensates and vaporize at least a portion of the aqueous condensates to obtain a water vapor stream having a temperature T1 and a pressure p1. The second water vapor stream can preferably be combined with the compressed water vapor stream after the first compression step. From the proposed example below, it can be seen that when a second steam stream is combined with a compressed steam stream, less energy consumption is required in the compression process, which is typically the form of power consumption for a heat pump compressor, in order to obtain a compressed steam stream with temperature T2 and pressure p2. As a result, when a second steam stream is combined with a compressed steam stream, the COP (Coefficient of Performance) of the heat pump as the generated stream is higher relative to the power consumed.

[0051] manufacturing equipment In a further embodiment, the present invention relates to an energy recovery system, A heat exchanger for transferring heat from a high-temperature fluid stream to an aqueous condensate to obtain a water vapor stream having temperature T1 and pressure p1, Means for compressing one or more, preferably 1 to 5, more preferably 2 to 4, most preferably 2 or 3, water vapor streams having temperature T1 and pressure p1, connected in series, to obtain a compressed water vapor stream having temperature T2 and pressure p2, preferably at least one, for example, one or two, preferably one heat pump compressor, each heat pump compressor comprising one or more, preferably 1 to 5, more preferably 2 to 4, most preferably 2 or 3 compression stages connected in series, and A means for using a compressed water vapor stream having a pressure p2 for energy recovery, thereby obtaining a stream containing aqueous condensate, Means for transporting a steam stream from a heat exchanger to means for compressing a first steam stream, Optionally, means for transporting a compressed water vapor stream from one upstream means for compressing a water vapor stream to the next downstream means for compressing a water vapor stream, among a set of means for compressing a water vapor stream. A means for transporting a compressed water vapor stream having a pressure p2 from the last of a series of means for compressing a water vapor stream to a means for using the compressed water vapor stream having a temperature T2 and pressure p2 for energy recovery. Regarding equipment including...

[0052] The equipment can be any type of equipment that generates a high-temperature fluid stream that can be used for energy recovery. Non-limiting examples include, for example, industrial manufacturing sites such as chemical manufacturing sites, particularly polymerization manufacturing sites, power generation facilities, and facilities including engines or electronic equipment or housings.

[0053] The equipment is preferably adapted to all aspects and embodiments of the method of the present invention for recovering steam as described above or below.

[0054] In the case of a chemical manufacturing site, the equipment preferably further includes means for producing chemical products, such as one or more reactors. Furthermore, the equipment preferably includes means for post-processing of chemical products, such as means for purifying chemical products and / or means for compounding chemical products, or other means necessary for processing and finishing chemical products. Furthermore, the equipment preferably includes means for transporting educt, products and / or other components used in the chemical manufacturing process to means for manufacturing chemical products, from means for manufacturing chemical products to means for post-processing of chemical products, and means for process steps between them.

[0055] In the polymerization process described above, the means for producing the chemical product preferably include a polymerization reactor. The polymerization reactor may be a single polymerization reactor or multiple polymerization reactors connected in series. A polymerization reactor can be selected from a slurry-phase reactor, such as a loop reactor, and a gas-phase reactor, such as a fluidized-bed gas-phase reactor. The multiple polymerization reactors are preferably two or more polymerization reactors, and preferably two to six polymerization reactors, for example, two, three, four, five, or six polymerization reactors connected in series. Multiple polymerization reactors are typically selected from slurry-phase reactors, such as loop reactors, and gas-phase reactors, such as fluidized-bed gas-phase reactors.

[0056] Means for processing polymer powder downstream from at least one polymerization reactor preferably include means for separating the polymer from unreacted monomers, comonomers, and other components of the product stream. Furthermore, means for processing polymer powder downstream from at least one polymerization reactor preferably include means for compounding the polymer, such as an extruder.

[0057] The equipment includes at least one heat exchanger. The equipment may include a plurality of heat exchangers, for example, at least one set of at least two heat exchangers connected in series. The number of sets of at least two heat exchangers connected in series may be 1 to 10, for example, 1, 2, 3, 4, 5, or 6. A set of at least two heat exchangers connected in series may include two or more heat exchangers connected in series, for example, two to six, preferably two, three, or four, most preferably two.

[0058] In a polymerization manufacturing plant, the number of sets of at least two heat exchangers connected in series typically depends on the number of polymerization reactors and the number of means for processing polymer powder downstream from at least one polymerization reactor. One set of at least two heat exchangers connected in series can be connected to means for processing polymer powder downstream from each polymerization reactor and / or at least one polymerization reactor of the manufacturing facility, preferably means for compounding the polymer, such as an extruder.

[0059] The apparatus includes means for compressing one or more, preferably 1 to 5, more preferably 2 to 4, most preferably 2 or 3, steam streams having temperature T1 and pressure p1 to obtain a compressed steam stream having pressure p2. One or more means for compressing the water vapor stream are preferably connected in series. One or more means for compressing the water vapor stream is preferably one or more, for example, one or two, preferably one heat pump compressor. Each heat pump compressor preferably includes 1 to 5, more preferably 2 to 4, and most preferably 2 or 3 compression stages connected in series. One or more, for example, one or two, preferably one heat pump compressor, is preferably part of one or more heat pumps as known in the art.

[0060] The equipment further includes means for using a compressed steam stream having a pressure p2 for energy recovery. This means for using a compressed steam stream for energy recovery can also be used as a means for using a compressed steam stream as a heating medium. In industrial manufacturing settings, means for using a steam stream as a heating medium may be means for heating a product stream, any other stream, or a component of the manufacturing site at any stage of the industrial production process, or even within the heating system of the manufacturing equipment. Such means may be a heat exchanger, a reboiler, or a heating system. Means for energy recovery may also include means for temporarily storing a high-temperature and / or high-pressure stream before use. Means for using a compressed steam stream for energy recovery may also be means for applying methods that utilize a backcondensation reaction, such as a chemical heat pump, which has been commercialized by Qpinch and is described, for example, in particular, in International Publication No. 2014 / 016405A1.

[0061] The means for transporting the steam stream from the heat exchanger to a first means for compressing the steam stream is preferably a pipe for connecting the means for transporting the steam stream from the heat exchanger to the first means for compressing the steam stream. The heat exchanger is preferably directly connected to a first means for compressing a steam stream by means for transporting the steam stream from the heat exchanger to the first means for compressing the steam stream. In this context, “directly connected” means that the means are not connected to any further means for manipulating the temperature or pressure of the steam stream.

[0062] When multiple means for compressing a steam stream are connected in series, the equipment includes means for transporting the compressed steam stream from one upstream means for compressing the steam stream to the next downstream means for compressing the steam stream, within the series of means for compressing the steam stream. Preferably, the means for transporting the compressed water vapor stream from one upstream means for compressing the water vapor stream to a subsequent downstream means for compressing the water vapor stream is preferably a pipe for connecting one upstream means for compressing the water vapor stream to the subsequent downstream means for compressing the water vapor stream. Preferably, in a series of means for compressing a water vapor stream, each upstream means for compressing the water vapor stream is connected to a next downstream means for compressing the water vapor stream via means for transporting the compressed water vapor stream from one upstream means for compressing the water vapor stream to the next downstream means for compressing the water vapor stream. Upstream and subsequent downstream means for compressing a water vapor stream can be directly connected via means for transporting the compressed water vapor stream from one upstream means for compressing the water vapor stream to the subsequent downstream means for compressing the water vapor stream. In this context, “directly connected” means that the means are not connected to any further means for manipulating the temperature or pressure of the water vapor stream.

[0063] However, it is preferable that the equipment further includes at least one means for compressing the steam stream, preferably downstream of each means, for cooling the compressed steam stream. At least one means for compressing a water vapor stream, preferably a means for cooling the compressed water vapor stream downstream of each means, is preferably a means for combining the compressed water vapor stream with a higher-pressure aqueous condensate and a portion of the aqueous condensate obtained from means for using a compressed water vapor stream having a pressure p2 for energy recovery. At least one means for compressing a water vapor stream, preferably a preferred means for cooling the compressed water vapor stream downstream of each means, is most preferably a superheat reducer as known in the art.

[0064] The equipment also includes means for transporting a compressed steam stream having a pressure p2 from the last of a series of means for compressing the steam stream to means for using the compressed steam stream having a pressure p2 for energy recovery. Means for transporting a compressed steam stream having pressure p2 from the last of a series of means for compressing a steam stream to means for using the compressed steam stream having pressure p2 for energy recovery are preferably pipes for connecting, preferably directly, the last of a series of means for compressing a compressed steam stream having pressure p2 to means for using the compressed steam stream having pressure p2 for energy recovery. In this regard, “directly connected” means that the means are not connected to any further means for manipulating the temperature or pressure of the compressed steam stream having pressure p2.

[0065] The equipment in question, • Means for separating a second water vapor stream and aqueous condensate from a stream containing aqueous condensate obtained from means for using a compressed water vapor stream, • Means for transporting a stream containing aqueous condensate from means for using a compressed water vapor stream to means for separating a second water vapor stream and aqueous condensate from the stream containing aqueous condensate, • Means for transporting the second steam stream from means for separating the second steam stream and aqueous condensate to means for cooling the compressed steam stream downstream from the first (initial) upstream means for compressing the steam stream. It is preferable to further include the following.

[0066] The means for separating a second steam stream and aqueous condensate from a stream containing aqueous condensate obtained from means for using a compressed steam stream may be any means suitable for separating a liquid stream from a gaseous stream, such as a steam-liquid separator known in the art.

[0067] The means for transporting the stream containing aqueous condensate from means for using a compressed steam stream for energy recovery to means for separating a second steam stream and aqueous condensate from the stream containing aqueous condensate is preferably a pipe for connecting, preferably directly, the means for using a compressed steam stream for energy recovery to the means for separating a second steam stream and aqueous condensate from the stream containing aqueous condensate. In this regard, “directly connected” means that the means is not connected to any further means for manipulating the temperature or pressure of the stream containing aqueous condensate.

[0068] Means for transporting the second steam stream from means for separating the second steam stream and aqueous condensate to means for cooling the compressed steam stream downstream from the first upstream means for compressing the steam stream are preferably pipes for connecting, preferably directly, the means for separating the second steam stream and aqueous condensate to means for cooling the compressed steam stream downstream from the first upstream means for compressing the steam stream. In this regard, “directly connected” means that the means are not connected to any further means for manipulating the temperature or pressure of the second steam stream.

[0069] The manufacturing equipment preferably further includes means for transporting a stream containing aqueous condensate from means for using a compressed steam stream for energy recovery to a heat exchanger for transferring heat from a high-temperature fluid stream of a chemical manufacturing process to the aqueous condensate in the stream containing aqueous condensate. The means for transporting a stream containing aqueous condensate from means for using a compressed steam stream for energy recovery to a heat exchanger for transferring heat from a high-temperature fluid stream to the aqueous condensate in the stream containing aqueous condensate is preferably a pipe for connecting, preferably directly, the means for using a compressed steam stream for energy recovery to a heat exchanger for transferring heat from a high-temperature fluid stream of a chemical manufacturing process to the aqueous condensate in the stream containing aqueous condensate. In this regard, “directly connected” means that the means are not connected to any further means for manipulating the temperature or pressure of the stream containing aqueous condensate.

[0070] This means that the means for transporting the stream containing aqueous condensate preferably passes through a second steam stream and means for separating the aqueous condensate from the stream containing aqueous condensate obtained from means for using a compressed steam stream for energy recovery.

[0071] use In a further embodiment, the present invention relates to the use of both of the above or below methods or manufacturing equipment for compressing a steam stream having a pressure p1 to obtain a compressed steam stream having a temperature T2 and pressure p2 for direct energy recovery, comprising one or more, preferably 1 to 5, more preferably 2 to 4, most preferably 2 or 3, means for compressing a steam stream, preferably at least 1, for example 1 or 2, preferably 1, heat pump compressors, each heat pump compressor comprising one or more, preferably 1 to 5, more preferably 2 to 4, most preferably 2 or 3, compression stages connected in series, wherein the means compress a steam stream having a pressure p1 to obtain a compressed steam stream having a temperature T2 and pressure p2.

[0072] Preferably, all aspects and embodiments of one or more means, methods, or manufacturing equipment for heating and compressing a series-connected steam stream according to the present invention, as described above or below, are applicable to the use of the present invention.

[0073] Detailed description of the drawings and proposed embodiments Figure 1 shows a schematic diagram of the conventional heat recovery step from a fluidized bed gas-phase reactor in which heat is transferred from a circulating gas stream to the working fluid during the heat exchange process. The heat from the working fluid is used to vaporize the aqueous condensate to obtain a stream of water vapor for further use in the polymerization process. To increase heat recovery, the working fluid is subjected to a heating and compression step, in which the working fluid is first preheated in a preheater and then further heated and compressed in a heat pump compressor. As a result, more energy can be transferred to the aqueous condensate, and the resulting water vapor has a higher temperature and pressure. However, since the heat transfer step is always associated with energy loss due to suboptimal heat transfer, a more efficient method of water vapor recovery is needed.

[0074] Figure 2 shows a schematic diagram of one embodiment of the method of the present invention, in which heat is transferred from a high-temperature fluid stream at any stage of a chemical manufacturing process to an aqueous condensate in a heat exchanger such as a waste heat reboiler, and the aqueous condensate is vaporized to obtain a steam stream. The high-temperature fluid stream before entering the heat exchanger typically has a temperature of 40 to 140°C. The aqueous condensate preferably has a temperature of 80 to 99°C and a high pressure of about 5 to 8 bar(a) before entering the heat exchanger. During heat transfer, the aqueous condensate is vaporized to obtain a steam stream with a temperature T1 of 40 to 134°C and a pressure p1 of 0.06 to 3 bar(a). This steam stream is subjected to two subsequent compression steps in two subsequent heat pump compressors, in which a compressed steam stream has a temperature and pressure in the range of 150 to 300°C and 4 to 10 bar(a), thereby enabling the direct use of the compressed steam stream in the chemical manufacturing process. If, after the first and second compression steps, the temperature of the steam stream exceeds 300°C, the temperature of the steam stream can be reduced in a superheat reducer by introducing a portion of the aqueous condensate stream at temperature T1 and pressure p1. After use in the chemical manufacturing process, the steam stream is usually condensed and reused for heat transfer. Therefore, the aqueous condensate cycle also includes valves for guiding excess steam to an external user and introducing external steam as needed. The steam stream introduced to the steam user within the manufacturing process has a temperature T2 in the range of 144-180°C and a pressure p2 of 4-10 bar(a). After use, the steam stream partially or completely condenses to a temperature of 80-99°C and a pressure of 1 bar(a). The condensed stream is collected in a condensate collector. To reuse the aqueous condensate in heat transfer, the pressure of the aqueous condensate is increased to 5-8 bar(a) as described above.

[0075] Figure 3 shows a schematic diagram of another embodiment of the method of the present invention in which a condensed steam stream used in a chemical manufacturing process is separated into an aqueous condensate and a second steam stream having a temperature of 100–121°C and a pressure of 1.01–2 bar(a). The aqueous condensate is reused for heat transfer, while the second steam stream is combined with the heated and compressed steam stream after the first heating and compression step.

[0076] Figure 4 shows a proposed example of the embodiment shown in Figure 2. This example is proposed using ASPEN Plus. A water condensate stream (S1) having a temperature of 80°C, a pressure of 7 bar(a), a vapor fraction of 0 wt%, and a mass flow rate of 12,000 kg / hr is subjected to a heat exchange process in a heat exchanger to cool a high-temperature fluid stream. The water condensate stream is vaporized into a steam stream (S2) having a temperature of 65°C, a pressure of 0.23 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 12,000 kg / hr. The steam stream is subjected to a first compression process in the first compression stage of a heat pump compressor so that the steam stream has a temperature of 234°C, a pressure of 1 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 12,000 kg / hr (S4). To cool the steam stream, the steam stream is combined with a higher-pressure water stream in a first superheat reducer. A higher-pressure aqueous stream has a temperature of 80°C, a pressure of 7 bar(a), a vapor fraction of 0 wt%, and a mass flow rate of 1300 kg / hr (S6). After the first superheat reducer, the cooled steam stream has a temperature of 106°C, a pressure of 1 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 13300 kg / hr (S5). This cooled steam stream is subjected to a second compression step in the second compression stage of the heat pump compressor, such that the steam stream has a temperature of 198°C, a pressure of 2 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 13300 kg / hr (S8). To cool the steam stream, the steam stream is combined with a higher-pressure aqueous stream in a second superheat reducer. A higher-pressure water stream has a temperature of 80°C, a pressure of 7 bar(a), a vapor fraction of 0 wt%, and a mass flow rate of 850 kg / hr (S13). After the second superheat reducer, the cooled water vapor stream has a temperature of 125°C, a pressure of 2 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 14150 kg / hr (S9). This cooled water vapor stream is subjected to a third compression step in the third compression stage of the heat pump compressor, so that the water vapor stream has a temperature of 197°C, a pressure of 4 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 14150 kg / hr (S10).To cool the steam stream, it is combined with a higher-pressure aqueous stream in a third superheat reducer. The higher-pressure aqueous stream has a temperature of 80°C, a pressure of 7 bar(a), a steam fraction of 0 wt%, and a mass flow rate of 650 kg / hr (S11). After the third superheat reducer, the cooled steam stream has a temperature of 146°C, a pressure of 4 bar(a), a steam fraction of 100 wt%, and a mass flow rate of 14800 kg / hr (S9). The compressed steam stream can be used for energy recovery.

[0077] Figure 5 shows a proposed example of the embodiment shown in Figure 3. This example is proposed using ASPEN Plus. A water condensate stream (S1) having a temperature of 80°C, a pressure of 7 bar(a), a vapor fraction of 0 wt%, and a mass flow rate of 11260 kg / hr is subjected to a heat exchange process in a heat exchanger to cool a high-temperature fluid stream. This water condensate stream is vaporized into a steam stream (S2) having a temperature of 65°C, a pressure of 0.23 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 11260 kg / hr. This steam stream is subjected to a first compression process in the first compression stage of a heat pump compressor so that the steam stream has a temperature of 234°C, a pressure of 1 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 11260 kg / hr (S4). To cool the steam stream, this steam stream is combined with a higher-pressure water stream in a first superheat reducer. A higher-pressure water stream has a temperature of 80°C, a pressure of 7 bar(a), a vapor fraction of 0 wt%, and a mass flow rate of 1200 kg / hr (S6). In addition, a second steam stream (S7) with a temperature of 101°C, a pressure of 1 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 840 kg / hr is introduced into the first superheat reducer and combined with the other two streams. After the first superheat reducer, the cooled steam stream has a temperature of 107°C, a pressure of 1 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 13300 kg / hr (S5). The cooled steam stream is then subjected to a second compression step in the second compression stage of the heat pump compressor, so that the steam stream has a temperature of 200°C, a pressure of 2 bar(a), a vapor fraction of 100 wt%, and a mass flow rate of 13300 kg / hr (S8). To cool the steam stream, it is combined with a higher-pressure aqueous stream in a second superheat reducer. The higher-pressure aqueous stream has a temperature of 80°C, a pressure of 7 bar(a), a steam fraction of 0 wt%, and a mass flow rate of 850 kg / hr (S13). After the second superheat reducer, the cooled steam stream has a temperature of 127°C, a pressure of 2 bar(a), a steam fraction of 100 wt%, and a mass flow rate of 14150 kg / hr (S9).This cooled steam stream is subjected to a third compression step in the third compression stage of the heat pump compressor, such that the steam stream has a temperature of 198°C, a pressure of 4 bar(a), a steam fraction of 100% by weight, and a mass flow rate of 14150 kg / hr (S10). To cool the steam stream, it is combined with a higher-pressure aqueous stream in a third superheat reducer. The higher-pressure aqueous stream has a temperature of 80°C, a pressure of 7 bar(a), a steam fraction of 0% by weight, and a mass flow rate of 650 kg / hr (S11). After the third superheat reducer, the cooled steam stream has a temperature of 148°C, a pressure of 4 bar(a), a steam fraction of 100% by weight, and a mass flow rate of 14800 kg / hr (S9). This compressed stream is further used for heat exchange in a second heat exchanger where the compressed stream is condensed. The resulting aqueous condensate stream has a temperature of 144°C, a pressure of 4 bar(a), a vapor fraction of 0 wt% and a mass flow rate of 14800 kg / hr (S3), and can be used for energy recovery.

[0078] The proposed process, as shown in Figures 4 and 5, has the following energy consumption Q (load [kW]) and W (power [kW]), as well as a coefficient of performance (COP), which is the ratio of power consumption W to the generated water vapor, as shown in Table 1.

[0079] [Table 1]

Claims

1. An energy recovery method, a) A process of supplying a high-temperature fluid stream, b) A step of bringing the high-temperature fluid stream into thermal contact with the aqueous condensate in a heat exchanger, thereby transferring heat from the high-temperature fluid stream to the aqueous condensate, vaporizing at least a portion of the aqueous condensate, and obtaining a water vapor stream having a temperature T1 and a pressure p1. c) A step of subjecting the water vapor stream to at least one compression step to obtain a compressed water vapor stream having a pressure p2, d) A step of using the compressed water vapor stream for energy recovery, thereby obtaining a stream containing aqueous condensate. Includes, In at least one of the compression steps c), the temperature of the water vapor stream is raised to temperature T2. Temperature T2 is 50K to 250K higher than temperature T1. The ratio of pressure p2 to pressure p1, p2 / p1, is between 5 and 50. A method comprising: a stream containing the aqueous condensate obtained from the compressed steam stream used for heat recovery being subjected to a steam separation step to obtain a second steam stream and aqueous condensate, the second steam stream being combined with the compressed steam stream.

2. The method according to claim 1, wherein the high-temperature fluid stream has a temperature Tf of 20 to 150°C.

3. The method according to claim 1 or claim 2, wherein in step c), the water vapor stream is subjected to 1 to 5 compression steps.

4. The method according to claim 1 or claim 2, wherein in step c), the water vapor stream is subjected to two to four compression steps.

5. The method according to claim 1 or claim 2, wherein the temperature T2 is 65K to 150K higher than the temperature T1.

6. The method according to claim 1 or claim 2, wherein the aqueous condensate has a temperature Tc of 40°C to 99°C and / or a pressure pc of 1 to 10 bar(a).

7. The method according to claim 1 or claim 2, wherein the temperature T1 is in the range of 30°C to 150°C and / or the pressure p1 is in the range of 0.04 bar(a) to 4.76 bar(a).

8. The method according to claim 1 or 2, wherein in at least one compression step c), the temperature of the heated compressed water vapor stream is raised to a temperature T2, where the temperature T2 is in the range of 125°C to 300°C and / or the pressure p2 is in the range of 3 bar(a) to 12 bar(a).

9. The method according to claim 1 or 2, wherein the temperature of the compressed water vapor stream is reduced after one or more compression steps so that the temperature of the compressed water vapor stream does not exceed 300°C.

10. The method according to claim 9, wherein the temperature of the compressed water vapor stream after each compression step is reduced by combining the compressed water vapor stream with an aqueous condensate at a higher pressure.

11. The method according to claim 1 or 2, wherein the aqueous condensate obtained from the heated and compressed steam stream used is used to bring the high-temperature fluid stream into thermal contact with the aqueous condensate in a first heat exchanger.

12. The method according to claim 1 or 2, wherein the steam stream is subjected to the compression stage of a heat pump compressor in each compression step to obtain a compressed steam stream having a pressure p2.

13. It is equipment for recovering energy, A heat exchanger for transferring heat from a high-temperature fluid stream to an aqueous condensate to obtain a water vapor stream having temperature T1 and pressure p1, A means for compressing one or more water vapor streams connected in series, each having a temperature T1 and a pressure p1, to obtain a compressed water vapor stream having a temperature T2 and a pressure p2, A means for using the compressed water vapor stream having a pressure p2 for energy recovery, thereby obtaining a stream containing aqueous condensate, Means for transporting the steam stream from the heat exchanger to a first upstream means for compressing the steam stream, Means for transporting the compressed water vapor stream having pressure p2 from the last of a series of means for compressing the water vapor stream to means for using the compressed water vapor stream having pressure p2 for energy recovery, Means for cooling the compressed water vapor stream downstream from each means for compressing the water vapor stream, Means for separating a second water vapor stream and aqueous condensate from a stream containing aqueous condensate obtained from the means for using the compressed water vapor stream, Means for transporting the stream containing the aqueous condensate from the means for using the compressed water vapor stream for energy recovery to the means for separating the stream containing the aqueous condensate from a second water vapor stream and the aqueous condensate, Means for transporting the second steam stream from the means for separating the second steam stream and aqueous condensate to the means for cooling the compressed steam stream downstream from the first upstream means for compressing the steam stream, Manufacturing equipment, including.

14. Means for transporting the compressed water vapor stream from one upstream means for compressing the water vapor stream to the next downstream means for compressing the water vapor stream, among a series of means for compressing the water vapor stream. The manufacturing equipment according to claim 13, further comprising:

15. The manufacturing apparatus according to claim 13 or claim 14, comprising means for compressing one to five steam streams having temperature T1 and pressure p1, which are connected in series, to obtain a compressed steam stream having temperature T2 and pressure p2.

16. The manufacturing apparatus according to claim 13 or 14, wherein the means for compressing the steam stream having temperature T1 and pressure p1 is at least one heat pump compressor, each heat pump compressor comprising one or more compression stages connected in series.

17. Means for transporting the stream containing the aqueous condensate from the means for using the compressed steam stream for energy recovery to the heat exchanger for transferring heat from the high-temperature fluid stream to the aqueous condensate in the stream containing the aqueous condensate. The manufacturing equipment according to claim 13 or claim 14, further comprising:

18. Use in a manufacturing facility according to claim 1 or 2, or claim 13 or 14, for compressing a steam stream having temperature T1 and pressure p1, of one or more means for compressing a steam stream connected in series, to obtain a compressed steam stream having pressure p2 for direct energy recovery.

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