Method and plant for treating wastewater stream from acrylic acid and / or acrylate production plant

Abstract

The present disclosure provides a process for treating at least one wastewater stream from an acrylic acid and / or acrylate production plant. The method for treatment comprises the steps of: (a) introducing the at least one wastewater stream from the acrylic acid and / or acrylate production plant into a bioreactor (510), (b) reacting said at least one wastewater stream in said bioreactor (510) in the presence of at least one microorganism suitable for the decomposition of unwanted organic components under conditions of anaerobic microbial decomposition of unwanted organic components to obtain methane and carbon dioxide, (c) discharging from the bioreactor (510) a treated wastewater stream depleted of unwanted organic components relative to the at least one wastewater stream introduced into the bioreactor (510), and (d) incinerating a methane and carbon dioxide containing product gas stream discharged from the bioreactor (510) in the incineration plant (512) with an incineration air stream and optionally an auxiliary fuel stream.

Description

Technical Field

[0001] The present invention relates generally to wastewater stream treatment; more particularly, the present invention relates to a method and apparatus for treating at least one wastewater stream from an acrylic acid and / or acrylic ester production facility, wherein a bioreactor is configured for reacting the at least one wastewater stream under conditions of anaerobic microbial decomposition of the undesirable organic components in the presence of at least one microorganism suitable for decomposition of the undesirable organic components. Typically, the content of such undesirable organic components in the wastewater of acrylic acid and / or acrylic ester production ranges from 4% to 10% by weight. Background Art

[0002] Typically, wastewater from acrylic acid production plants contains a variety of biocidal components, such as acrolein, formaldehyde, etc., which makes conventional biological wastewater treatment difficult and uneconomical. Therefore, the presence of such components is undesirable. Due to the presence of biocidal components in the wastewater, the wastewater is usually transported to the incineration chamber of the production plant for decomposing organic components by burning the wastewater. In addition, the incineration chamber of the production plant is used to purify chemically contaminated waste gases, which are also discharged into the incineration chamber.

[0003] When burning such waste streams with a content of unwanted organic components in a lower range, a large amount of energy must be provided to heat the waste stream to a temperature at which the organic components undergo a sufficient degree of decomposition. Organic fuels are used as a source of energy for this purpose and are also fed into the incinerator. Only a small portion of the energy used can be recovered as heat from the exhaust gas and is generally used to generate steam. However, a large portion of the heat is still unused. Fossil fuels are used to generate unused heat, which increases operating costs and also results in the undesirable formation of carbon dioxide (CO2) released into the environment.

[0004] Therefore, there is a need to address the above-mentioned technical deficiencies in the prior art known when treating wastewater streams from acrylic acid and / or acrylic ester production plants. Summary of the invention

[0005] The present invention seeks to provide an improved method for treating at least one wastewater stream from an acrylic acid and / or acrylate production plant. The object of the present invention is to provide a solution that at least partially overcomes the problems encountered in the prior art and to provide a method and a device for treating at least one wastewater stream from an acrylic acid and / or acrylate production plant, wherein a bioreactor is configured to decompose unwanted organic components in the at least one wastewater stream under anaerobic conditions to obtain methane, carbon dioxide and treated wastewater. The methane- and carbon dioxide-containing product gas stream from the bioreactor is introduced into the incineration plant without an intermediate purification step, thereby significantly reducing the demand for fossil fuels in the incinerator in addition to replacing part of the residual fuel demand of the incineration plant, and at the same time reducing the carbon dioxide emissions of the plant. The objects of the present invention are achieved by the solutions provided in the attached independent claims. Advantageous specific implementations of the invention are further defined in the attached dependent claims.

[0006] According to a first aspect, the present invention provides a method for treating at least one wastewater stream from an acrylic acid and / or acrylic ester production plant, wherein the production plant comprises at least one functional unit selected from the group consisting of:

[0007] (1) an acrylic acid synthesis stage which operates by catalytic selective oxidation of an input stream comprising propene with an oxygen-containing oxidant stream to obtain a product mixture comprising acrylic acid,

[0008] (2) a post-treatment stage for separating acrylic acid from the acrylic acid-containing product mixture,

[0009] (3) an esterification stage for esterifying acrylic acid with at least one alcohol,

[0010] wherein the at least one wastewater stream contains unwanted organic components, in particular at least one compound selected from the group consisting of:

[0011] Acrolein, other aldehydes, for example, formaldehyde; formic acid, other organic acids, for example, acetic acid; ethers,

[0012] The method for processing comprises the following steps:

[0013] (a) providing at least one wastewater stream from an acrylic acid and / or acrylic ester production plant,

[0014] (b) introducing the at least one wastewater stream into a bioreactor,

[0015] (c) reacting the at least one wastewater stream in a bioreactor under conditions of anaerobic microbial decomposition of the undesirable organic components in the presence of at least one microorganism suitable for the decomposition of the undesirable organic components to produce methane and carbon dioxide,

[0016] (d) discharging from the bioreactor a treated wastewater stream depleted of undesirable organic components relative to the at least one wastewater stream introduced into the bioreactor,

[0017] (e) discharging a product gas stream comprising methane and carbon dioxide from the bioreactor, and

[0018] (f) introducing the product gas stream containing methane and carbon dioxide into an incineration device, incinerating the product gas stream containing methane and carbon dioxide in the incineration device with an incineration air stream and an optional auxiliary fuel stream, and discharging a flue gas stream from the incineration device.

[0019] The advantage of the method for treating at least one wastewater stream from an acrylic acid and / or acrylate production plant is that the method is capable of degrading unwanted organic components in the at least one wastewater stream by reacting the at least one wastewater stream under conditions of anaerobic microbial decomposition in a bioreactor to produce methane, carbon dioxide and treated wastewater. The product gas stream containing methane and carbon dioxide from the bioreactor is advantageously used in an incineration plant without the need for an intermediate purification step to replace part of the fuel demand of the incineration plant, thereby significantly reducing the demand for fossil fuels in the incinerator and thereby reducing the operating costs of the incineration plant. At the same time, carbon dioxide emissions from the plant are also reduced. The treated wastewater can be discharged directly into open water bodies or further treated in one or more treatment steps in advance.

[0020] According to a second aspect, the present invention provides a plant for treating at least one wastewater stream from an acrylic acid and / or acrylic ester production plant, wherein the production plant comprises at least one functional unit selected from the group consisting of:

[0021] (1) an acrylic acid synthesis stage which operates by catalytic selective oxidation of an input stream comprising propene with an oxygen-containing oxidant stream to obtain a product mixture comprising acrylic acid,

[0022] (2) a post-treatment stage for separating acrylic acid from the acrylic acid-containing product mixture,

[0023] (3) an esterification stage for esterifying acrylic acid with at least one alcohol,

[0024] The device comprises the following further components and functional units which are fluidically connected to one another:

[0025] (a) means for providing the at least one wastewater stream from an acrylic acid and / or acrylic ester production plant, wherein the at least one wastewater stream contains undesirable organic components;

[0026] (b) a bioreactor configured for reacting the at least one wastewater stream under conditions of anaerobic microbial decomposition of undesirable organic components to produce methane and carbon dioxide in the presence of at least one microorganism suitable for decomposition of the undesirable organic components; means for introducing the at least one wastewater stream into the bioreactor;

[0027] (c) means for discharging a treated wastewater stream from the bioreactor, wherein the treated wastewater stream is depleted of undesirable organic components relative to the at least one wastewater stream introduced into the bioreactor;

[0028] (e) means for discharging a product gas stream comprising methane and carbon dioxide from the bioreactor; and

[0029] (f) an incineration device; a device for introducing the product gas stream containing methane and carbon dioxide into the incineration device, a device for introducing an incineration air stream and an optional auxiliary fuel stream into the incineration device; and a device for discharging a flue gas stream from the incineration device.

[0030] The advantage of the device for treating at least one wastewater stream from an acrylic acid and / or acrylate production plant is that the bioreactor of the device is capable of degrading the unwanted organic components in the at least one wastewater stream by reacting the at least one wastewater stream in the bioreactor under conditions of anaerobic microbial decomposition to produce methane, carbon dioxide and treated wastewater. The product gas stream containing methane and carbon dioxide from the bioreactor is advantageously used in an incineration plant without intermediate purification steps to replace part of the fuel demand of the incineration plant, thereby significantly reducing the demand for fossil fuels in the incinerator and thus reducing the operating costs of the incineration plant. At the same time, the carbon dioxide emissions of the device are also reduced. The treated wastewater can be discharged directly into open water bodies or further treated in one or more treatment steps in advance.

[0031] Embodiments of the present invention eliminate the above-mentioned disadvantages in the currently known methods for treating at least one wastewater stream from an acrylic acid and / or acrylate production plant by integrating a bioreactor into the production plant to decompose unwanted organic components under anaerobic microbial decomposition conditions, and utilizing the methane and carbon dioxide containing product gas stream from the bioreactor to replace part of the fuel demand of the incineration plant so as to reduce the demand for fossil fuels in the incinerator and reduce the carbon dioxide emissions of the plant.

[0032] Additional aspects, advantages, features and objects of the present invention become apparent from the accompanying drawings and detailed description of illustrative embodiments interpreted in conjunction with the appended claims. It should be understood that the features of the present invention are susceptible to being combined in various combinations without departing from the scope of the invention defined by the appended claims.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above summary of the invention and the following detailed description of illustrative embodiments may be better understood when read in conjunction with the accompanying drawings. In order to illustrate the present invention, exemplary structures of the present invention are shown in the accompanying drawings. However, the present invention is not limited to the specific methods and means disclosed herein. In addition, it will be appreciated by those skilled in the art that the accompanying drawings are not drawn to scale. Where possible, identical elements have been indicated by identical numerals. Embodiments of the present invention will now be described by way of example and with reference to the following figures, in which:

[0035] Figure 1 is a schematic diagram of the prior art acrylic acid synthesis stages for producing an acrylic acid-containing product mixture;

[0036] Figure 2 is a schematic diagram of prior art work-up stages for separating acrylic acid from a product mixture containing acrylic acid;

[0037] Figure 3 is a schematic diagram of a prior art esterification stage for esterifying acrylic acid with at least one alcohol;

[0038] Figure 4 is a block diagram of a prior art apparatus for producing acrylic acid and / or acrylic acid esters from a wastewater stream; and

[0039] Figure 5 is a block diagram of an apparatus for treating at least one wastewater stream from an acrylic acid and / or acrylic ester production plant according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following detailed description illustrates embodiments of the invention and ways in which these embodiments may be implemented. Although some modes of carrying out the invention have been disclosed, those skilled in the art will recognize that other embodiments for carrying out or practicing the invention are possible.

[0041] As used herein, several terms are defined as follows:

[0042] The conditions for anaerobic or aerobic microbial decomposition are known to the person skilled in the art from the prior art. These are the physicochemical conditions in the respective bioreactor, including temperature, pressure, pH and flow rates of reactants and products, under which a measurable, preferably industrially relevant, conversion of hydrocarbons into anaerobic or aerobic microbial decomposition is achieved.

[0043] The conditions of the acrylic acid synthesis stage, the post-treatment stage and the esterification stage of acrylic acid and / or acrylic ester production equipment are known to those skilled in the art from the prior art. These are the physicochemical conditions in the individual reactors / towers, including temperature, pressure, pH, flow rates of reactants and products.

[0044] Unwanted organic components are understood to be components which are formed unintentionally during the synthesis of acrylic acid and / or acrylic esters, whether as by-products or degradation products of the chemical reactions which occur or during the workup or further processing of the intermediates or end products of the synthesis. Examples of such undesired organic components are acrolein, further aldehydes, for example formaldehyde; formic acid, further organic acids, for example acetic acid; ethers. Typically, the content of such undesired organic components in the wastewater from the production of acrylic acid and / or acrylic esters is in the range of 4 to 10% by weight.

[0045] Pressure, if any, is reported in absolute units (referred to as bar(a)) or gauge units (referred to as bar(g)), unless otherwise indicated in the specific individual context.

[0046] A fluid connection between two regions of a device or apparatus according to the present invention is understood to mean any type of connection that enables a fluid (e.g., an airflow) to flow from one region of the two regions to the other region, ignoring any intervening regions or components. In particular, a direct fluid connection is understood to mean any type of connection that enables a fluid (e.g., an airflow) to flow directly from one region of the two regions to the other region, without any additional regions or components intervening, except for pure transport operations and the devices required therefor (e.g., pipes, valves, pumps, compressors, reservoirs). An example is a pipeline that leads directly from one region of the two regions to the other region.

[0047] Means is understood to mean something that is capable of achieving or contributing to achieving an objective. In particular, means for carrying out a particular method step is understood to mean any physical item that a person skilled in the art would consider in order to be able to carry out that method step. For example, a person skilled in the art would consider means for introducing or discharging a material flow to include any transport and delivery equipment, i.e., for example, pipes, pumps, compressors, valves, which appear necessary or reasonable for said skilled person to use for carrying out that method step based on his knowledge of the art.

[0048] For the purpose of this description, steam is to be understood as synonymous with water vapor, unless otherwise indicated in individual cases. Conversely, the term "water" refers to water in the liquid state, unless otherwise indicated in individual cases.

[0049] Optional or optionally means that the subsequently described event or circumstance may or may not occur. The description includes instances where the event or circumstance occurs and instances where the event or circumstance does not occur.

[0050] "Provide" in the claims is defined to mean to equip, supply, make available, or prepare something. In the absence of explicit language to the contrary in the claims, any participant may perform a step.

[0051] According to a first aspect, the present invention provides a method for treating at least one wastewater stream from an acrylic acid and / or acrylic ester production plant, wherein the production plant comprises at least one functional unit selected from the group consisting of:

[0052] (1) an acrylic acid synthesis stage which operates by catalytic selective oxidation of an input stream comprising propene with an oxygen-containing oxidant stream to obtain a product mixture comprising acrylic acid,

[0053] (2) a post-treatment stage for separating acrylic acid from the acrylic acid-containing product mixture,

[0054] (3) an esterification stage for esterifying acrylic acid with at least one alcohol,

[0055] wherein the at least one wastewater stream contains unwanted organic components, in particular at least one compound selected from the group consisting of:

[0056] Acrolein, other aldehydes, for example, formaldehyde; formic acid, other organic acids, for example, acetic acid; ethers,

[0057] The method for processing comprises the following steps:

[0058] (a) providing at least one wastewater stream from an acrylic acid and / or acrylic ester production plant,

[0059] (b) introducing the at least one wastewater stream into a bioreactor,

[0060] (c) reacting the at least one wastewater stream in a bioreactor under conditions of anaerobic microbial decomposition of the undesirable organic components in the presence of at least one microorganism suitable for the decomposition of the undesirable organic components to produce methane and carbon dioxide,

[0061] (d) discharging from the bioreactor a treated wastewater stream depleted of undesirable organic components relative to the at least one wastewater stream introduced into the bioreactor,

[0062] (e) discharging a product gas stream comprising methane and carbon dioxide from the bioreactor, and

[0063] (f) introducing the product gas stream containing methane and carbon dioxide into an incineration device, incinerating the product gas stream containing methane and carbon dioxide in the incineration device with an incineration air stream and an optional auxiliary fuel stream, and discharging a flue gas stream from the incineration device.

[0064] The advantage of the method for treating at least one wastewater stream from an acrylic acid and / or acrylate production plant is that the method is able to degrade the unwanted organic components in the at least one wastewater stream by reacting the at least one wastewater stream under conditions of anaerobic microbial decomposition in a bioreactor to produce methane, carbon dioxide and treated wastewater. The product gas stream containing methane and carbon dioxide from the bioreactor is advantageously used in an incineration plant without intermediate purification steps to replace part of the fuel demand of the incineration plant, thereby significantly reducing the demand for fossil fuels in the incinerator and thus reducing the operating costs of the incineration plant. At the same time, the carbon dioxide emissions of the plant are also reduced. Advantageously, the method of the present invention can obtain a wastewater quality that meets all commonly specified regulations.

[0065] Optionally, the acrylic acid-containing product mixture is produced by a two-stage reactor comprising a first-stage reactor and a second-stage reactor.

[0066] Optionally, the treated wastewater stream obtained in step (d) is sent to an additional treatment step, a purification step or a disposal step. Optionally, the treated wastewater stream obtained in step (d) is sent directly to a locally available municipal or industrial wastewater treatment facility, or after one or more additional treatment steps, is discharged to open waters.

[0067] Optionally, at least one additional waste stream or by-product stream is obtained in the acrylic acid and / or acrylate production facility. The at least one additional waste stream or by-product stream comprises at least one element selected from the group consisting of a waste gas stream, a wastewater stream, a solid waste stream, a waste stream containing a melt. The at least one additional waste stream or by-product stream is also sent to the incineration facility. Optionally, the at least one additional waste stream or by-product stream is incinerated in the incineration facility using a product gas stream containing methane and carbon dioxide from a bioreactor.

[0068] Optionally, at least one wastewater stream from an acrylic acid and / or acrylate production plant is first introduced into a buffer vessel and subsequently from the buffer vessel into the bioreactor. Thus, the process of the invention makes the composition of the at least one wastewater stream uniform and reduces possible fluctuations in the concentration of undesirable organic components.

[0069] Optionally, at least one wastewater stream from an acrylic acid and / or acrylate production plant is mixed with at least one additive prior to introduction into the bioreactor, wherein the at least one additive is selected from the group comprising:

[0070] Water; an acid aqueous solution, preferably an HCl aqueous solution, an alkali metal hydroxide aqueous solution, preferably a NaOH solution; a chelate former, preferably EDTA; a nutritional supplement for microorganisms, preferably an inorganic or mineral nutritional supplement, most preferably containing Na, K, Ca, P, SO4 2- nutritional supplements.

[0071] Optionally, the reaction of at least one wastewater stream in a bioreactor is carried out in the presence of at least one Methanobacterium microorganism under conditions of anaerobic microbial decomposition of undesirable organic components.

[0072] Optionally, at least a portion of the treated wastewater stream discharged from the bioreactor is recycled to the inlet of the bioreactor as a dilution stream. Thus, the dilution stream is able to reduce and control the concentration of unwanted organic components at the input of the bioreactor. In addition, the dilution stream reduces possible fluctuations in the concentration of unwanted organic components in the bioreactor.

[0073] Optionally, before introduction into the incineration plant, the product gas stream containing methane and carbon dioxide is compressed using a compressor to a pressure between 5 mbar(g) and 10 bar(g), or preferably between 50 mbar(g) and 2 bar(g), most preferably 100 mbar(g) to 1 bar(g).

[0074] Optionally, using a flue gas stream discharged from an incineration plant, by indirect heat exchange in at least one heat exchanger,

[0075] heating of at least one first material stream used in an acrylic acid and / or acrylic ester production plant, and / or

[0076] At least one first steam flow is generated, which is at least partly used to drive the compressor and / or to generate electrical energy. Thus, the overall energy and / or heat balance of the method can be further improved.

[0077] Optionally, at least one first material stream in the acrylic acid and / or acrylic ester production plant is selected from the group comprising:

[0078] A propene-containing input stream, an oxygen-containing oxidant stream, at least one water stream and / or a steam stream for heating at least one distillation column present in the workup stage for separating acrylic acid from an acrylic acid-containing product mixture.

[0079] Optionally, the heat released during the reaction of the at least one wastewater stream in the bioreactor under conditions of anaerobic microbial decomposition of unwanted organic components is at least partially used to preheat the at least one wastewater stream before introducing the stream into the bioreactor. Thus, the overall energy and / or heat balance of the process can be further improved.

[0080] Optionally, at least one of the wastewater streams is sent to at least one further purification step such that the concentration of undesirable organic components in the wastewater stream reaches or falls below a specified threshold.

[0081] Optionally, at least one further purification step comprises a treatment step under conditions of aerobic microbial decomposition of unwanted organic components.

[0082] According to a second aspect, the present invention provides a plant for treating at least one wastewater stream from an acrylic acid and / or acrylic ester production plant, wherein the production plant comprises at least one functional unit selected from the group consisting of:

[0083] (1) an acrylic acid synthesis stage which operates by catalytic selective oxidation of an input stream comprising propene with an oxygen-containing oxidant stream to obtain a product mixture comprising acrylic acid,

[0084] (2) a post-treatment stage for separating acrylic acid from the acrylic acid-containing product mixture,

[0085] (3) an esterification stage for esterifying acrylic acid with at least one alcohol,

[0086] The device comprises the following further components and functional units which are fluidically connected to one another:

[0087] (a) means for providing the at least one wastewater stream from an acrylic acid and / or acrylic ester production plant, wherein the at least one wastewater stream contains undesirable organic components;

[0088] (b) a bioreactor configured for reacting the at least one wastewater stream under conditions of anaerobic microbial decomposition of undesirable organic components to produce methane and carbon dioxide in the presence of at least one microorganism suitable for decomposition of the undesirable organic components; means for introducing the at least one wastewater stream into the bioreactor;

[0089] (c) means for discharging a treated wastewater stream from the bioreactor, wherein the treated wastewater stream is depleted of undesirable organic components relative to the at least one wastewater stream introduced into the bioreactor;

[0090] (e) means for discharging a product gas stream comprising methane and carbon dioxide from the bioreactor; and

[0091] (f) an incineration device; a device for introducing the product gas stream containing methane and carbon dioxide into the incineration device, a device for introducing an incineration air stream and an optional auxiliary fuel stream into the incineration device; and a device for discharging a flue gas stream from the incineration device.

[0092] The advantage of the device for treating at least one wastewater stream from an acrylic acid and / or acrylate production plant is that the bioreactor of the device is capable of degrading the unwanted organic components in the at least one wastewater stream by reacting the at least one wastewater stream in the bioreactor under conditions of anaerobic microbial decomposition to obtain methane, carbon dioxide and treated wastewater. The product gas stream containing methane and carbon dioxide from the bioreactor is advantageously used in the incineration plant without the need for intermediate purification steps to replace part of the fuel demand of the incineration plant, thereby significantly reducing the demand for fossil fuels in the incinerator and thus reducing the operating costs of the incineration plant. At the same time, the carbon dioxide emissions of the device are also reduced. The treated wastewater can be discharged directly into open water bodies or further treated in one or more treatment steps in advance. Advantageously, the device of the present invention can obtain a wastewater quality that meets all commonly specified regulations.

[0093] Optionally, the device is configured and / or means are provided so that a flue gas stream discharged from the incineration device is used, by indirect heat exchange in at least one heat exchanger,

[0094] heating of at least one first material stream used in an acrylic acid and / or acrylic ester production plant, and / or

[0095] At least one first steam flow is generated, which is at least partially used to drive a compressor and / or to generate electrical energy.

[0096] Embodiments of the present invention substantially eliminate or at least partially address the aforementioned technical deficiencies in the prior art for treating at least one wastewater stream from an acrylic acid and / or acrylate production plant by integrating a bioreactor into the production plant for decomposing unwanted organic components under anaerobic microbial decomposition conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Figure 1Schematic diagram of a prior art acrylic acid synthesis stage 100 for producing a product mixture containing acrylic acid. The acrylic acid synthesis stage 100 includes a first stage reactor 102, a second stage reactor 104, an absorber 106, a first waste heat boiling unit 108, a second waste heat boiling unit 110, and an incinerator device 112. The first stage reactor 102 is configured to catalytically oxidize a propylene-containing input stream 114 together with an oxygen-containing oxidant stream 116 and steam 118 to form a gas stream containing acrolein. The first waste heat boiling unit 108 is configured to utilize heat from the gas stream containing acrolein to produce a hot water stream or steam. The second stage reactor 104 is configured to catalytically oxidize the gas stream containing acrolein to form a gas stream containing acrylic acid. The second waste heat boiling unit 110 is configured to utilize heat from the gas stream containing acrylic acid to produce a hot water stream or steam. The gas stream containing acrylic acid is sent to the absorber 106, where acrylic acid is absorbed in water 120 to form a product mixture containing acrylic acid. The product mixture containing acrylic acid is sent to an additional purification step 122. The upstream exhaust gas is sent to the incinerator device 112 to incinerate the exhaust gas. At least a portion of the exhaust gas is recycled back to the first stage reactor 102.

[0098] Figure 22 is a schematic diagram of a prior art post-processing stage 200 for separating acrylic acid from an acrylic acid-containing product mixture 214. The post-processing stage 200 includes an extraction column 202, a raffinate stripping column 204, a solvent separation column 206, a light ends cutting column 208, an acrylic acid product column 210, and a decomposition evaporator 212. The acrylic acid-containing product mixture 214 from the acrylic acid synthesis stage is provided to the extraction column 202. The extraction column 202 is configured to separate acrylic acid from the acrylic acid-containing product mixture by liquid-liquid extraction using a solvent and obtain an extractant stream containing acrylic acid and acetic acid as a top product. The raffinate stream from the extraction column 202 is provided to the raffinate stripping column 204 for stripping the solvent from the raffinate stream. The extractant stream is provided to the solvent separation column 206 for separating the solvent from the extractant stream and obtaining a crude acrylic acid mixture as a bottom product. The two-phase overhead stream from the solvent separation tower 206 is separated into an organic phase containing the solvent which is recycled to the extraction tower 202 and an aqueous phase which is mixed with the raffinate stream. The crude acrylic acid mixture is provided to a light ends cutter 208 for separating acetic acid 216 and / or light ends from the crude acrylic acid mixture and obtaining an acrylic acid-containing stream as a bottom product. The light ends are light hydrocarbon gases and liquids. The acrylic acid-containing stream is provided to an acrylic acid product tower 210 for purifying the acrylic acid-containing stream to obtain purified acrylic acid 218 as an overhead product. The bottom stream containing acrylic acid dimers from the acrylic acid product tower 210 is provided to a decomposition evaporator 212 for decomposing acrylic acid dimers into monomers. The acrylic acid monomers from the decomposition evaporator 212 are recycled to the acrylic acid product tower 210. Waste oil is obtained as a bottom product from the decomposition evaporator 212, which is further incinerated.

[0099] Figure 33 is a schematic diagram of a prior art esterification stage 300 for esterifying acrylic acid with at least one alcohol. The esterification stage 300 includes an esterification reactor 302, an ester stripper 304, a bottom stripper 306, an alcohol extraction column 308, a light ends cutter 310, an alcohol recovery column 312, and an acrylic acid ester product column 314. The esterification reactor 302 is configured to react acrylic acid from the post-treatment stage with an alcohol feed using a strong acid catalyst. The effluent from the esterification reactor 302 is provided to the ester stripper 304 for separation of unreacted acrylic acid as a bottom product, which is recycled to the esterification reactor 302. A product mixture containing a first crude acrylic acid ester is obtained as a top product from the ester stripper 304. Optionally, the bottom stripper 306 is configured to decompose a portion of the unreacted acrylic acid to obtain acrylic acid monomers, which are recycled to the esterification reactor 302. The product mixture containing the first crude acrylic acid ester is provided to the alcohol extraction column 308 for extracting alcohol from the product mixture containing the first crude acrylic acid ester. The bottom product containing alcohol is provided to an alcohol recovery column 312 for recovering alcohol from the bottom product as a top product, and the recovered alcohol is recycled to the esterification reactor 302. A portion of the bottom product from the alcohol recovery column 312 is provided to an alcohol extraction column 308 for extracting alcohol. The top product from the alcohol extraction column 308 is provided to a light fraction cutting column 310 for separating light fractions from the top product. The bottom product from the light fraction cutting column 310 is provided to an acrylate product column 314 for separating high boiling point components from the bottom product, and obtaining a final product 316 containing purified acrylate.

[0100] Figure 4 4 is a block diagram of a prior art apparatus 400 for producing acrylic acid and / or acrylic esters using a wastewater stream. The apparatus 400 includes at least one functional unit selected from the group consisting of an acrylic acid synthesis stage 402, a post-processing stage 404, and an esterification stage 406, and an incineration apparatus 408. The acrylic acid synthesis stage 402 is configured to operate by catalytically selectively oxidizing an input stream containing propylene with an oxygen-containing oxidant stream 410 to obtain a product mixture containing acrylic acid. The post-processing stage 404 is configured to separate acrylic acid from the product mixture containing acrylic acid. The esterification stage 406 is configured to esterify acrylic acid with at least one alcohol to obtain a product 412 containing acrylic esters. The incineration apparatus 408 is configured to incinerate at least one wastewater stream and / or waste gas stream from the acrylic acid synthesis stage 402 and / or the post-processing stage 404 and / or the esterification stage 406 with an incineration air stream 414 and an optional auxiliary fuel stream 416, and to discharge a flue gas stream 418 from the incineration apparatus 408.

[0101] Figure 55 is a block diagram of an apparatus 500 for treating at least one wastewater stream from an acrylic acid and / or acrylic acid ester production plant according to an embodiment of the present invention. The acrylic acid and / or acrylic acid ester production plant comprises an acrylic acid synthesis stage 502, a post-treatment stage 504 and an esterification stage 506. The apparatus 500 comprises the following additional components and functional units connected to each other in fluid: a buffer container 508, a bioreactor 510, an incineration device 512, a recirculation pump 514, a compressor 516, an input flow providing device 518, an acrylic acid-containing product mixture discharge device 520, an acrylic acid discharge device 522, an acrylic acid-containing product discharge device 524, a wastewater flow providing device 526, a wastewater flow introduction device 528, a treated wastewater discharge device 530, a product gas flow discharge device 532, an additive introduction device 534, a diluent flow providing device 536, a product gas flow introduction device 538, an incineration air flow introduction device 540, an auxiliary fuel flow introduction device 542, and a flue gas discharge device 544.

[0102] The input stream providing device 518 is configured to provide the input stream containing propylene and the oxygen-containing oxidant stream to the acrylic acid synthesis stage 502. The acrylic acid synthesis stage 502 is configured to operate by catalytically selectively oxidizing the input stream containing propylene with the oxygen-containing oxidant stream to obtain a product mixture containing acrylic acid, and discharge the product mixture containing acrylic acid through the acrylic acid-containing product mixture discharge device 520. The post-treatment stage 504 is configured to separate acrylic acid from the acrylic acid-containing product mixture and discharge acrylic acid through the acrylic acid discharge device 522. The esterification stage 506 is configured to esterify acrylic acid with at least one alcohol and discharge a product containing acrylic acid ester through the acrylic acid ester product discharge device 524.

[0103] Despite Figure 5 In the example shown, all units 502, 504, and 506 are fluidly connected to the wastewater flow providing device 526, but the present invention also relates to examples not shown in the figure, in which any one of the units 502, 504, and 506 is fluidly connected to the wastewater flow providing device 526 alone, or any combination of two of the units 502, 504, and 506 is fluidly connected to the wastewater flow providing device 526.

[0104] The wastewater stream providing device 526 is configured to provide at least one wastewater stream from the acrylic acid synthesis stage and / or the post-treatment stage 504 and / or the esterification stage 506. The at least one wastewater stream from the acrylic acid and / or acrylate production plant is first introduced into the buffer container 508 and then introduced into the bioreactor 510 from the buffer container 508. The bioreactor 510 is configured to receive the at least one wastewater stream through the wastewater stream introducing device 528 and react the at least one wastewater stream under conditions of anaerobic microbial decomposition of the undesirable organic components in the presence of at least one microorganism suitable for decomposition of the undesirable organic components to obtain methane and carbon dioxide. Optionally, before introduction into the bioreactor 510, the at least one wastewater stream from the acrylic acid and / or acrylate production plant is mixed with at least one additive. The at least one additive is introduced into the bioreactor 510 through the additive introducing device 534. The treated wastewater discharge device 530 is configured to discharge from the bioreactor 510 a treated wastewater stream depleted of undesirable organic components relative to the at least one wastewater stream introduced into the bioreactor 510. Optionally, the treated wastewater stream obtained from the bioreactor 510 is sent to another treatment step, purification step or disposal step. At least a portion of the treated wastewater stream discharged from the bioreactor 510 is recycled to the inlet of the bioreactor 510 as a dilution stream through the recirculation pump 514. The diluent stream providing device 536 is configured to provide a portion of the treated wastewater stream to the recirculation pump 514. The product gas stream discharge device 532 is configured to discharge a product gas stream containing methane and carbon dioxide from the bioreactor 510. The incineration device 512 is configured to receive the product gas stream containing methane and carbon dioxide through the product gas stream introduction device 538, and incinerate the product gas stream containing methane and carbon dioxide using an incineration air stream and an optional auxiliary fuel stream. The incineration air stream is introduced into the incineration device 512 through the incineration air stream introduction device 540. The auxiliary fuel stream is introduced into the incineration device 512 through the auxiliary fuel stream introduction device 542. The flue gas discharge device 544 is configured to discharge a flue gas stream from the incineration device 512. Optionally, before introduction into the incineration device 512, the product gas stream containing methane and carbon dioxide is compressed using a compressor 516 to a pressure between 5 mbar(g) and 10 bar(g), or preferably between 50 mbar(g) and 2 bar(g), and most preferably 100 mbar(g) to 1 bar(g).

[0105] The foregoing embodiments of the invention may be modified without departing from the scope of the invention as defined in the appended claims. Expressions used to describe and claim the invention, such as "comprising", "including", "incorporating", "having", "being" are intended to be interpreted in a non-exclusive manner, i.e. allowing for the presence of items, components or elements not expressly described. Reference to the singular shall also be interpreted as relating to the plural.

[0106] The various embodiments described above may be combined to provide additional embodiments. All U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications, and non-patent publications cited in this specification and / or listed in the application data sheet, including European Patent Application No. 22210444.0 filed on November 30, 2022, are incorporated herein by reference in their entirety. If necessary, aspects of the embodiments may be modified to adopt the concepts of various patents, applications, and disclosures to provide yet further embodiments.

[0107] In light of the above detailed description, these and other changes can be made to the embodiments. In general, in the following claims, the terms used should not be interpreted to limit the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted to include all possible embodiments and the full range of equivalents to which these claims are entitled. Therefore, the claims are not limited by the present disclosure.

[0108] Reference numerals list

[0109] 100-Acrylic acid synthesis stage

[0110] 102-First stage reactor

[0111] 104-Second stage reactor

[0112] 106-Absorption Tower

[0113] 108-First waste heat boiling unit

[0114] 110-Second waste heat boiling unit

[0115] 112-Incinerator equipment

[0116] 114-Input stream containing propylene

[0117] 116-Oxygen-containing oxidant stream

[0118] 118-Steam

[0119] 120-Water

[0120] 122-Additional purification steps in the acrylic acid synthesis stage

[0121] 200-Post-processing stage

[0122] 202-Extraction Tower

[0123] 204-Raffinate Stripping Tower

[0124] 206-Solvent separation tower

[0125] 208-Light fraction cutting tower

[0126] 210-Acrylic acid product tower

[0127] 212-Decomposition evaporator

[0128] 214-Product mixture containing acrylic acid

[0129] 216-Acetic acid

[0130] 218-Purified acrylic acid

[0131] 300-Esterification stage

[0132] 302-Esterification Reactor

[0133] 304-Ester Stripping Tower

[0134] 306-Bottom Stripper

[0135] 308-Alcohol extraction tower

[0136] 310-Light fraction cutting tower

[0137] 312-Alcohol recovery tower

[0138] 314-Acrylate Product Tower

[0139] 316-Purified Acrylate

[0140] 400-Device

[0141] 402-Acrylic acid synthesis stage

[0142] 404-Post-processing stage

[0143] 406-Esterification stage

[0144] 408-Incineration Equipment

[0145] 410 - Input stream containing propylene and oxidant stream containing oxygen

[0146] 412-Products containing acrylate

[0147] 414-Incineration air flow

[0148] 416 - Optional Auxiliary Fuel Stream

[0149] 418-Flue Flow

[0150] 500-device

[0151] 502-Acrylic acid synthesis stage

[0152] 504-Post-processing stage

[0153] 506-Esterification stage

[0154] 508-Buffer Container

[0155] 510-Bioreactor

[0156] 512-Incineration equipment

[0157] 514-Recirculation Pump

[0158] 516-Compressor

[0159] 518-Input stream providing device

[0160] 520-Discharge device for product mixture containing acrylic acid

[0161] 522-Acrylic acid discharge device

[0162] 524-Product discharge device containing acrylic esters

[0163] 526-Wastewater Flow Providing Device

[0164] 528-Wastewater flow introduction device

[0165] 530- Treated wastewater discharge device

[0166] 532-Product gas flow discharge device

[0167] 534-Additive introduction device

[0168] 536-Diluent flow providing device

[0169] 538-Product gas flow introduction device

[0170] 540-Incineration air flow introduction device

[0171] 542-Auxiliary fuel flow introduction device

[0172] 544- Flue gas discharge device

Claims

1. A method for treating at least one wastewater stream from an acrylic acid and / or acrylic ester production plant, wherein the production plant comprises at least one functional unit selected from the group consisting of: (1) an acrylic acid synthesis stage (502) which operates by catalytically selectively oxidizing an input stream containing propylene with an oxygen-containing oxidant stream to obtain a product mixture containing acrylic acid, (2) a post-processing stage (504) for separating acrylic acid from the acrylic acid-containing product mixture, (3) an esterification stage (506) for esterifying acrylic acid with at least one alcohol, wherein the at least one wastewater stream contains unwanted organic components, in particular at least one compound selected from the group consisting of: Acrolein, other aldehydes, for example, formaldehyde; formic acid, other organic acids, for example, acetic acid; ethers, The method for processing comprises the following steps: (a) providing said at least one wastewater stream from said acrylic acid and / or acrylic ester production plant, (b) introducing the at least one wastewater stream into a bioreactor (510), (c) reacting said at least one wastewater stream in said bioreactor (510) under conditions of anaerobic microbial decomposition of undesirable organic components in the presence of at least one microorganism suitable for decomposition of the undesirable organic components to produce methane and carbon dioxide, (d) discharging from the bioreactor (510) a treated wastewater stream depleted of undesirable organic components relative to the at least one wastewater stream introduced into the bioreactor (510), (e) discharging a product gas stream comprising methane and carbon dioxide from the bioreactor (510), and (f) introducing the product gas stream containing methane and carbon dioxide into an incineration device (512), incinerating the product gas stream containing methane and carbon dioxide in the incineration device (512) with an incineration air stream and an optional auxiliary fuel stream, and discharging a flue gas stream from the incineration device (512).

2. The method according to claim 1, characterized in that The treated wastewater stream obtained in step (d) is sent to a further treatment step, a purification step or a disposal step.

3. The method according to claim 1 or 2, characterized in that: At least one further waste stream or by-product stream is obtained within the acrylic acid and / or acrylic ester production plant, wherein the at least one further waste stream or by-product stream comprises at least one element selected from the group consisting of: Waste gas streams, wastewater streams, solid waste streams, waste streams containing melts, Wherein the at least one additional waste stream or by-product stream is also sent to the incineration facility (512).

4. The method according to any one of the preceding claims, characterized in that The at least one wastewater stream from the acrylic acid and / or acrylic ester production plant is first introduced into a buffer vessel (508) and subsequently from the buffer vessel (508) into the bioreactor (510).

5. The method according to any one of the preceding claims, characterized in that Prior to introduction into the bioreactor (510), the at least one wastewater stream from the acrylic acid and / or acrylate production facility is mixed with at least one additive, wherein the at least one additive is selected from the group comprising: Water; an acid aqueous solution, preferably an HCl aqueous solution, an alkali metal hydroxide aqueous solution, preferably a NaOH solution; a chelate former, preferably EDTA; a nutritional supplement for microorganisms, preferably an inorganic or mineral nutritional supplement, most preferably containing Na, K, Ca, P, SO4 2- nutritional supplements.

6. The method according to any one of the preceding claims, characterized in that The reaction of the at least one wastewater stream in the bioreactor (510) is carried out under conditions of anaerobic microbial decomposition of undesirable organic components in the presence of at least one microorganism of the genus Methanobacterium.

7. The method according to any one of the preceding claims, characterized in that At least a portion of the treated wastewater stream discharged from the bioreactor (510) is recycled to the inlet of the bioreactor (510) as a dilution stream.

8. The method according to any one of the preceding claims, characterized in that Prior to introduction into the incineration device (512), the product gas stream containing methane and carbon dioxide is compressed using a compressor (516) to a pressure between 5 mbar(g) and 10 bar(g), or preferably between 50 mbar(g) and 2 bar(g), and most preferably between 100 mbar(g) and 1 bar(g).

9. The method according to any one of the preceding claims, characterized in that Using the flue gas stream discharged from the incineration plant (512), by indirect heat exchange in at least one heat exchanger, heating at least one first material stream used in the acrylic acid and / or acrylic ester production plant, and / or At least one first steam flow is generated, the at least one first steam flow being used at least in part to drive a compressor (516) and / or to generate electrical energy.

10. The method according to claim 9, characterized in that The at least one first material flow in the acrylic acid and / or acrylic ester production plant is selected from the group consisting of: A propene-containing input stream, an oxygen-containing oxidant stream, at least one water stream and / or a steam stream for heating at least one distillation column present in the post-treatment stage (504) for separating acrylic acid from the acrylic acid-containing product mixture.

11. The method according to any one of the preceding claims, characterized in that The heat released during the reaction carried out in the bioreactor (510) under conditions of anaerobic microbial decomposition of unwanted organic components in the at least one wastewater stream is at least partially used to preheat the stream before introducing the at least one wastewater stream into the bioreactor (510).

12. The method according to any one of the preceding claims, characterized in that The at least one wastewater stream is sent to at least one further purification step such that the concentration of the undesirable organic components in the wastewater stream reaches or falls below a specified threshold.

13. The method according to any one of the preceding claims, characterized in that The at least one further purification step comprises a treatment step under conditions of aerobic microbial decomposition of the unwanted organic components.

14. A device (500) for treating at least one wastewater stream from an acrylic acid and / or acrylic ester production plant, wherein the production plant comprises at least one functional unit selected from the group consisting of: (1) an acrylic acid synthesis stage (502) which operates by catalytically selectively oxidizing an input stream containing propylene with an oxygen-containing oxidant stream to obtain a product mixture containing acrylic acid, (2) a post-processing stage (504) for separating acrylic acid from the acrylic acid-containing product mixture, (3) an esterification stage (506) for esterifying acrylic acid with at least one alcohol, The device (500) comprises the following further components and functional units which are fluidically connected to each other: (a) means (526) for providing said at least one wastewater stream from said acrylic acid and / or acrylic ester production facility, wherein said at least one wastewater stream contains undesirable organic components; (b) a bioreactor (510) configured to react the at least one wastewater stream under conditions of anaerobic microbial decomposition of undesirable organic components to produce methane and carbon dioxide in the presence of at least one microorganism suitable for decomposition of the undesirable organic components; means (528) for introducing the at least one wastewater stream into the bioreactor (510); (c) means (530) for discharging a treated wastewater stream from the bioreactor (510), wherein the treated wastewater stream is depleted of undesirable organic components relative to the at least one wastewater stream introduced into the bioreactor (510); (e) means (532) for discharging a product gas stream comprising methane and carbon dioxide from said bioreactor (510); and (f) an incineration device (512); a device (538) for introducing the product gas stream containing methane and carbon dioxide into the incineration device (512); a device (540, 542) for introducing an incineration air stream and an optional auxiliary fuel stream into the incineration device (512); and a device (544) for discharging a flue gas stream from the incineration device (512).

15. The device (500) according to claim 14, characterized in that The device (500) is configured and / or means are provided so that the flue gas stream discharged from the incineration device (512) is used by indirect heat exchange in at least one heat exchanger, heating at least one first material stream used in the acrylic acid and / or acrylic ester production plant, and / or At least one first steam flow is generated, the at least one first steam flow being used at least in part to drive a compressor (516) and / or to generate electrical energy.

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