TWI254781B - Method for reducing waste oxide gas emissions in industrial processes - Google Patents

Abstract

The method of the present invention reduces the emissions of waste oxide gas produced within a thermal oxidizer by the use of a multizone waste thermal oxidizer, comprising at least one primary combustion zone and at least one downstream waste destruction zone. By performing the primary combustion of fuel prior to the destruction of at least a portion of the waste, it has been discovered that NOx emissions from the waste destruction process can be reduced economically and without significant loss of overall waste destruction efficiency.

Description

1254781 发明, INSTRUCTION DESCRIPTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method of reducing undesired emissions in an industrial process. More particularly, the invention relates to a method of reducing the production of spent oxide gases during a thermal oxidation reaction. Standing ~ [Prior Art] Thermal oxidizers are typically used to process waste streams from industrial processes. In a typical thermal oxidizer, the waste stream and oxidant are combined at elevated temperatures to break down the waste. If the waste stream is sufficiently mixed with the oxidant and the waste is maintained at elevated temperatures in the thermal oxidizer for a sufficient period of time, the waste destruction will occur via a combination of oxidative reactions. It is often also necessary to provide fuel flow to the thermal oxidizer. The fuel stream is combusted in a hot oxidizer to maintain the desired waste: destroying the temperature. In some cases, waste heat recovery, such as heat recovery: strips of fly boilers (HRSB), can also be combined with thermal oxidizers, but this is not the primary goal. In the case of a thermal oxidizer, it is necessary to first maximize the waste destruction efficiency' and the use of HRSB is purely arbitrary. Due to the high temperatures required to maintain destructive efficiency (usually 6 〇〇 or higher), spent oxide gases ("W0G") are usually produced as thermal oxidizers. The waste emulsifier gas is nitrogen-containing. A gas of an oxide (Ν〇χ), a sulfur-based oxide ("S〇X)/carbon-based oxide (C〇x), or a combination thereof. These spent oxide gas systems are produced by a variety of methods, including chemistry, combustion or heat. Waste oxide gases can produce undesirable effects when in the environment. For example, nitrogen-based oxides play a major role in the formation of ozone, and they are believed to be the cause of acid rain.

O:\88\88218.DOC 1254781 Acidification of rivers, acceleration of decay of buildings and monuments, reduction in visibility and adverse health effects. Carbon compounds, most notably carbon monoxide, may be associated with serious public health issues and have been associated with global warming. Due to these serious adverse environmental and health effects, the waste oxide gas that is introduced to the environment is strictly managed by national and regional institutions. “The specifications are expected to become even more restrictive in the coming year. Thermal Oxidizers, - The purpose is to destroy the spent compounds, preferably to convert them into harmless carbon dioxide and water. Therefore, the above-mentioned w〇G production is an undesirable effect (industry is preferably minimized). Although many different proposals have been made for thermal oxidizers. Design and structure, but all contain - high temperature waste destruction zone and thus produce at least some WOG. One phase converts heat from fuel combustion to steam compared to thermal emulsification. Industrial weaving (also known as public steel furnace, city) The sales_, public steel furnace or direct-fired steel furnace) comprises at least one combustion zone (commonly referred to as a "furnace" zone) and at least a steam boiler zone. Steam from industrial boilers can be used to heat applications - such as steam in refineries - or more generally, steam is used to provide propulsion for steam turbine installations (connected to electrical energy generators). In addition to this difference, industrial boilers also produce w〇G due to operation. Since the industrial pin furnaces in use have more hot oxidizers, most of the (10) discharge reduction work has so far focused on improving industrial steel furnaces rather than thermal oxidizers. Specifically, _Government and woven fabric manufacturers have made significant efforts to reduce emissions from industrial steel furnaces. Emission reduction method developed by this work (4) - Fact: The furnace uses a limited number of materials - mainly coal and high purity natural gas - and these fuels are fairly fixed

O:\88\88218.DOC 1254781 is composed and used at a substantially fixed burn rate. It is revealed that some industrially known industrial boiler emission reduction methods are also applicable to industrial thermal oxidizers. Unfortunately, these methods have limited use. All industrial boiler emission reduction methods involve a large amount of cost, operation and maintenance costs. This makes these methods economically unobtrusive when applied to waste reduction systems, where blind application of boiler methods associated with industrial thermal oxidizers may result in reduced waste destruction efficiency and often produce waste oxides such as The gas itself is a by-product that is unfavorable to the environment. The conventional waste oxide gas reduction method for industrial boilers can be divided into two broad categories: combustion reforming and post-combustion. The reduction method for suppressing the formation of N0x is referred to as "combustion modification" and includes a low N0x burner, over combustion air, reburning flue gas recirculation, and operational upgrading. The restoration method that destroys once formed is called the post-combustion method." Post combustion methods include selective catalyst reduction, selective non-catalyst reduction, and mixing. Low enthalpy combustion (LNBs) is a Utg modified method designed to control the mixing of fuel and air to achieve equivalent phase combustion. Staged combustion involves some of the combustion in the initial stage and additional combustion in the reburning stage of the waste destruction unit. Therefore, the staged reduction simultaneously reduces the flame temperature and oxygen concentration during certain combustion stages, which also reduces enthalpy and fuel N〇x production. In order to achieve a staged combustion of the fuel gas, in addition to the fuel gas delivered to the primary combustion stage, a reburning stage must be provided. The potential advantages of this application are offset by the consumption of excess combustion gases in the reburning portion of the unit. Changing some steel furnace operating parameters can be produced in the furnace will reduce the production of helium

O:\88\88218.DOC 1254781 Conditions - These changes are commonly referred to as operational modification methods. Examples include parking burner (BOOS), low excess air (LEA), and bias combustion (7) F). Conventional combustion reforming methods, such as those disclosed above, are capital intensive or have modified T' in certain operations to be detrimental to achieving the desired waste destruction efficiency. The reduction method of NOX formed as described above is referred to as "post-combustion method", and includes selective catalyst reduction (SCR), selective non-catalytic reduction (SNCR), and a mixing method. It should be noted that when the conventional post-combustion method achieves a certain degree of reduction in the amount of w〇g, there is no undesired environmental disadvantage in Asia and Africa. For example, use causes ammonia and -oxidation: nitrogen is released into the environment. The released ammonia can cause adverse effects downstream of the sncr system' including air heater fouling, plume formation, and significant fly ash contamination. SCR may also have undesirable effects, such as increased release of undesirable sulfur oxides and high gas side pressure drop. Furthermore, control and storage (necessary for SNCR and SCR methods) cause serious problems, and the SCR reduction method uses zeolite or precious metal catalyst. These catalysts are not only expensive to purchase but also consume at the end of their useful life. f These catalysts are also sensitive to contaminants (such as sulfur compounds) and the system may be prone to fouling (eg, sulfur (4) is formed in situ). Maintenance costs are increased by means of material damage and often require special continuous emissions monitoring to monitor the effectiveness of the system. J. The seven industries that reduce the waste oxide gas associated with the thermal oxidizer have many disadvantages. Therefore, there is a cloud, a low-capital, and a high-rate method that provides a thermal oxidizer that operates within the minimum waste oxide gas emission mode during the waste destruction process. Maintain the best break

O:\88\882I8.DOC 1254781 does not require a binary rate, and there is a need to provide a thermal oxidizer that produces a reduced amount of spent oxide gas at the beginning, and the fuel gas downstream of the combustion zone. SUMMARY OF THE INVENTION A new method for reducing the exhaust gas body in an industrial process is provided. Another embodiment of the present invention provides a novel waste destruction process that produces reduced waste waste emissions. Familiar with this technique... After studying the instructions and attaching the patent (4), you can understand: Temple and other new features. Thus, one embodiment of the present invention provides a new method for reducing the generation of helium emissions. The method of Jt et al. comprises the steps of directing the waste stream to thermal oxidation: burning at least a portion of the waste in the primary combustion zone of the thermal oxidizer: And arranging at least a portion of the waste stream downstream of the thermal oxidizer to break the waste material. The waste stream contains at least G·5 mol% of the reactive waste component and an inert component of 99.5 mol%. Preferably, the waste stream comprises at least about a mole of reactive waste material and up to about 98 mole percent of the inert component. The method of the present invention further comprises supplying an aqueous waste stream to the primary combustion zone. 3 The step of the present invention is to supply auxiliary waste to the downstream waste damage zone, wherein the auxiliary waste is selected from the group consisting of aqueous waste and alternative waste. The process of the present invention can be used in combination with an industrial process in which the product produced by the industrial process is selected from the group consisting of acrylic acid, methacrylic acid, acrolein, methacrylic acid, hydrogenated hydrogen, acrylonitrile, mercapto acrylonitrile, ruthenium anhydride, A group of maleic anhydride and its mixtures. Another specific embodiment of the invention relates to a method for reducing waste oxygen in industrial chemical processes

O:\88\88218 DOC -10- 1254781 A method for the discharge of a chemical gas, wherein the industrial process produces a solvent selected from the group consisting of acrylic acid, methacrylic acid, acrolein, methacrolein, hydrogen cyanide, acrylonitrile, methacrylonitrile, A product of a group consisting of anhydrides, maleic anhydride, and mixtures thereof. Another embodiment of the present invention includes the steps of: directing a waste stream to a horizontal thermal oxidizer; burning at least a portion of the waste stream in a primary combustion zone of the thermal oxidizer; and injecting at least a portion of the waste stream downstream of the thermal oxidizer Waste destruction area. Another embodiment of the waste stream comprises at least about 5 mole percent of the reactive waste component and up to about 99.5 mole percent of the inert component. Another embodiment of the invention also includes supplying an aqueous waste stream to the primary combustion zone. Another embodiment of the present invention also includes supplying auxiliary waste to the downstream waste destruction zone, wherein the auxiliary waste is selected from the group consisting of aqueous waste and alternative waste. [Mode of Application] The present invention relates to a method for reducing emissions of waste oxide gases. In particular, waste oxide gas emissions within the thermal oxidizer can be reduced by the use of a multi-zone waste thermal oxidizer comprising at least one primary combustion zone and at least one downstream waste destruction zone. By primary combustion of the fuel prior to destroying at least a portion of the waste, it has been found that the waste oxide gas emissions from the waste destruction process can be economically reduced without significant loss of overall waste destruction efficiency. It has been further discovered that the addition of aqueous waste streams to the primary combustion zone can also effectively reduce the emission of spent oxide gases. Referring to the drawings herein, Fig. 1 shows a method for reducing the emission of waste oxide gas content according to an embodiment of the present invention. The same component symbols represent the same fluids, steps, and components. The thermal oxidizer 20 of Figure i is shown schematically as a multi-stage horizontal thermal oxidizer. In the specific example of Figure ,, oxidant stream 10

O:\88\88218.DOC -11 - 1254781 and the combustion fuel stream in the primary combustion zone 22 of the hot emulsifier 20. The combustion agent stream 10 contains - or a plurality of gases, 1 comprising to oxygen. Oxygen: Examples of agents include, but are not limited to, atmospheric air, pure oxygen: oxygen-enriched air, ozone, or oxygen-containing process exhaust gases. In some specific instances, = is mentioned: mixing the oxidant stream, but it may be advantageous to utilize two separate oxidant streams (individually introducing thermal emulsification, but sufficiently close to the thermal oxidizer) to promote a thorough internal mixing of the thermal oxidizer. For example, for safety and operational reasons, atmospheric airflow may be injected via a nozzle that is separate (but immediately adjacent) from the pure oxygen plus the spear. As shown in Figure 1, the 4-point oxidant stream 10 may also be diverted by the tee i i as appropriate to provide a supplemental oxidant stream 13. Injecting the supplemental oxidant stream 13 into one or more downstream waste destruction zones can increase waste destruction efficiency. In the embodiment of Figure i, the supplemental oxidant stream 13 is provided to the secondary waste destruction zone 26 via the addition point 23. The combustion fuel 12 is preferably natural gas, however, the combustion fuel may contain one or more of any mixture of components that release heat when reacted with an oxidant. Examples of suitable combustion fuels include, but are not limited to, fuel oils, hydrocarbon gases, hydrogen, combustible organics, and coal. The diagram illustrates that the combustion fuel stream 12 is injected into the primary combustion zone 22 at a single point. However, the combustion fuel stream 12 may be added via multiple points, or may be introduced into the primary combustion zone via a burner, bellows, mixer, distributor, injector, nozzle or other means for delivering combustion fuel to the primary combustion zone 22. twenty two. Similarly, a number of options can be used for the addition of oxidant to the primary combustion zone 22 and the waste destruction zone 26. The oxidant stream 10 and the combustion fuel stream 12 are mixed in the initial O:\88\88218.DOC -12-1254781 stage combustion zone 22 and are combusted to generate heat. In some embodiments, it may be advantageous to combine the combustion fuel pre-oxidant prior to or simultaneously with the addition to the combustion zone; 4 for this purpose, a common device such as a mixer, low NOx combustion||(LNB) or spray may be used. The choice of mist, suitable fuel and oxidant addition means is within the skill of the artisan' and will depend on a number of 'quantity numbers, including the type of fuel and oxidant used, the thermal oxidizer geometry and economic factors. Due to the high temperatures present in the primary combustion zone and the presence of nitrogen in the oxidant stream 10 and/or the combustion fuel stream 12, helium is produced during the combustion process. The combustion process usually also produces certain levels of carbon dioxide, carbon monoxide and water. The heat and combustion products from the primary combustion zone 22 flow into the adjacent primary waste destruction zone 24 and secondary waste destruction zone 26. Therefore, the primary waste destruction zone 24 is referred to as the "downstream" of the primary combustion zone 22, and the secondary waste destruction zone % is downstream of the primary waste destruction zone 24. The waste stream 14 is introduced into the thermal oxidizer 20 via a first waste destruction zone waste stream addition point 25. Waste stream 14 typically contains components or waste streams from industrial processes that are intended to be destroyed. Waste stream 14 can comprise a gas, a liquid, or a mixture of both, and can also contain inert ingredients such as water, diatomic nitrogen or carbon dioxide. The true component of the exhaust stream 14 will depend on the particular industrial process considered, but must contain at least a minimum amount of reactive waste constituents. The "reactive waste component" represents a waste component that reacts with oxygen, which is part of the waste oxide gas. Examples of such reactive waste components include, but are not limited to, aliphatic hydrocarbons, ammonia, acrolein, hydrogen, hydrogen cyanide, carbon monoxide, urea, and aromatic compounds. Although such compounds may contain oxygen atoms as part of their structure

O:\88\88218 DOC-13-1254781 (e.g., carbon monoxide), but oxygen-free compounds are generally preferred. The waste stream injected into the downstream waste destruction zone preferably comprises at least 〇·5 mol% of reactive waste constituents or no more than 99.5 mol% of inert constituents to effectively reduce WOG emissions. The waste stream contains at least 2 mole % of reactive waste components or no more than 98 moles. /〇Inert ingredients. In the specific example of FIG. 1, the first waste destruction zone waste stream addition point 25 is a single connection point of the outer surface of the oxidized to 20 outer surface, which is connected with a series of radials on the inside of the thermal oxidizer 2 The positioned dispensing nozzles are in communication. The nozzle provides a fluid around the thermal oxidizer 2 for improved distribution of mixing and destruction efficiency. The high temperature and oxygen in the thermal oxidizer destroy the waste components. Due to exposure to high temperatures in the thermal oxidizer, certain reactive waste components form groups that can remove oxygen from WOG compounds (eg, hydrazine), thereby converting them to inert compounds (eg, diatomic nitrogen and the like) ). These thermally induced groups are referred to herein as "reducing groups." Although the formation of the reducing group can theoretically occur in any high temperature environment, its presence usually remains temporarily in the primary reaction zone. Therefore, significantly reduced w〇G emissions cannot be obtained. It has been found that a desirable result of reduced WOG emissions can be obtained when at least a portion of the reactive waste constituents are introduced into the primary combustion zone. This post-primary combustion injection delays the formation of reactive groups and improves its efficiency in reducing W〇g emissions. Therefore, when the reactive waste component is present in the waste destruction zone downstream of the primary combustion zone, the W〇G emission can be effectively reduced. Industrial chemical processes relating to specific examples of thermal oxidizer levels include methods for producing hydrogen cyanide, acrolein, acrylonitrile, mercapto acrylonitrile, methacrolein, methacrylic acid, phthalic anhydride, maleic anhydride, and mixtures thereof .

O:\88\88213 DOC -14- !254781 It has been determined that certain reactive waste components are more effective at forming a reducing group initiated at a specific temperature, and thus are preferred (due to their greater w〇g reduction) "set). Thus, an aliphatic hydrocarbon (e.g., hexane) will be a preferred type of reactive waste component that is superior to an aromatic ring compound (e.g., stupid), and the burned species (e.g., propylene, rot will be more olefinic (e.g., propylene, Butene) is more preferred as a reactive waste component. Therefore, the use of alkanes (rather than alkenes) as the chemical chemist of the primary feed: particularly preferred for use in the process of the present invention. Examples include (but π are limited to) the production of acrylonitrile, acrylic acid and acrylonitrile by catalytic reaction of propylene and the production of methacrylic acid and methacrolein from C4_alkanes. The absorber waste gas waste is circulated: produced, and will contain at least a portion of the unreacted crude crude material feed. When such waste streams are injected into the thermal oxidizer according to the method of the present invention, it is expected to be derived from a similar A similar waste stream of the olefin-based process is more effective in reducing enthalpy. /Understanding that compounds such as (3), hydrazine, and cis-3 are known to be effective reducing agents' and thus will be desirable when used in accordance with the methods of the present invention. Wide ingredient. Figure 1 As shown, some of the waste stream 14 may also be modified by the tee tube as appropriate to provide a supplemental waste stream 7. By injecting the supplemental waste stream 17 into one or more downstream waste destruction zones, W〇G emissions may be enhanced. Reducing efficiency. In the specific example of Figure 1, the supplementary waste streamer 7 is provided to the secondary waste destruction zone 26 via the waste stream addition point π. The addition point 27 can be by burner, bellows, mixing, dispenser, syringe , nozzle or other such injection hardware. The reactive waste component of the supplementary waste stream 17 and the destruction of the secondary waste

O:\88\882I8.DOC -15 - 1254781 (not eliminated in primary waste destruction zone 24). Desirably, such W0G compound 2) the bulk gas reversal is such that n"c〇d 0 is shattered in the primary waste destruction zone 24 to circulate the effluent 32 to release: a compound that is not a contaminant and can be useless In some specific (4), it is expected that the waste stream (10) (or another = in the supplementary waste stream 7) is advantageously passed through a dedicated injection point or by mixing auxiliary waste. The thermal oxidizer t may be the same as::* containing a waste stream that can be derived from another part of the subject industrial process or from a complete δ/issued. These auxiliary waste streams may be = a waste material component 'and may further contain solids,: 八^, etc. - or a mixture of multiples. Examples of such auxiliary waste: (but not limited to) recovered spent fuel, organically contaminated wastewater, process venting, polymer sputum or mineral acid residues. Contains _ Α light library points (including C-, methanol and methyl propylene acid brewing) and special amines private residue (including third alkyl primary amine and C6 + hydrocarbon). In the specific example of the fixed waste stream, When the waste stream contains organically polluted wastewater, it is preferred that at least part of the liquid waste component is injected into the upstream zone of the thermal oxidizer, so that the residence time is maximized, and thus the waste destruction efficiency is improved. Injecting into the primary combustion zone. It should be understood that the dashed line 29 represents the boundary between many regions within the thermal oxidizer 20. The production line represents that the exact boundary between such regions in the thermal oxidizer is not static and may instead be altered during the waste destruction procedure. Position. Since the thermal oxidizer is a dynamic system, the boundary between the end of primary combustion and the start of waste destruction is not O:\88\88218 DOC -16 - 1254781 is completely immovable, but can be replaced by a thermal oxidizer 2 The length is then moved. Based on the implementation point of view, the fluid injection point is usually adequately separated from the front-fuel or waste injection point (M5 meters (0.5 inches) or more), and the independent downstream zone is maintained. The effluent leaving the secondary waste destruction zone 26 passes through the effluent from 3 〇 (where it is directed to the atmosphere). Guided flow, as appropriate The material 32 recovers some of the heat contained in the hunger 32 by heat recovery of a steam smelting furnace (HRSG) 28 or other heat recovery device. The heat energy is recovered by the autothermal oxidizer as steam, and the heat recovery of the effluent 32 is improved. The energy efficiency of the total waste destruction procedure. Figure 2 is a preferred embodiment of the present invention in an unintended form, wherein the thermal oxidation is 120 for a two-stage vertical thermal oxidizer. Due to reduced size and lower capital cost, The vertical structure is generally superior to the horizontal structure for the thermal oxidizer. In the vertical embodiment, the oxidant flowing and the combustion fuel are delivered to the primary combustion zone 122 of the thermal oxidizer 120 (the contents of the oxidant stream 11 与 and the combustion fuel) Stream 112 is combusted there. The enthalpy and other spent oxide gas systems are produced during combustion in primary combustion zone 122. The oxidant stream 110 contains one or more gases and contains from 1 to 1% oxygen. Examples of suitable emulsifiers include, but are not limited to, atmospheric air, pure 1% oxygen, ozoned air, ozone or oxygenated process exhaust gases. In some embodiments, it is not advantageous to provide a mixed oxidant stream, but it may be advantageous to utilize a separate oxidant stream (individually introduced into the thermal oxidizer, but in close proximity to the thermal oxidizer) to promote once thorough mixing of the thermal oxidizer. For example, for safety and pluggability reasons, the atmospheric air stream can be injected via a nozzle that is separate (but immediately adjacent) from the pure oxygen.

〇 \88\88218 DOC -17 - 1254781 The combustion fuel U2 is preferably natural gas, however, the combustion fuel may contain - or a mixture of any of the components that release heat when reacted with the oxidant. Examples of suitable combustion fuels include, but are not limited to, fuel oils, hydrocarbon gases: hydrogen, combustible organics, and coal. Figure 2 illustrates that the combustion fuel stream "2 is introduced into the primary combustion zone i22 via a single, .. However, the combustion fuel stream 112 may be added via multiple points, or may be introduced into the primary combustion zone via a burner, bellows, mixer, distributor, injector, nozzle, or other means for delivering combustion fuel to the primary combustion zone 122.丨 22. Similarly, a number of options can be used for the addition of oxidant to the primary combustion zone 1-2 and the waste destruction zone 124. The oxidant stream and the combustion fuel stream are mixed in the primary combustion zone 122 and are combusted to generate heat. In some embodiments, it may be advantageous to combine the combustion of the fuel with the oxidant at the same time as the addition of the fuel to the stagnation zone; for this purpose, a common device such as a mixer, low NOx combustion (LNB) or spray may be used. Mist. Suitable for fuel and oxidant addition devices 4 is within the capabilities of the skilled person, and will depend on the type of fuel and oxidant used in the G 3, thermal oxidizer geometry and economic factors. vertical,,,. Another advantage of the structured thermal oxidizer 12 is the simplification of non-porous components, such as liquid fuels and solid waste, which are optionally used. In the horizontal thermal oxidizer, the liquid energy 忐8 + + human L soil core, the full combustion of the knives depends on the uniform small diameter droplets / / (can be gasified at a constant rate and mixed in the combustion zone) Thermal oxidizer. In general: such droplets are formed using devices such as pressurized sprayers. When such an injection device is not used, it may result in the accumulation of liquid at the bottom of the horizontal thermal oxidizer and thus requires expensive maintenance and downtime. When used

0 \88\882I8.DOC -18 - 1254781 The vertical thermal oxidizer structure is low and the liquid droplets can be fully burned. The sensitivity to the spray variable greatly reduces the full length of the oxidizer in order to achieve the use of a vertical thermal oxidative crying mouth for additional points superior to horizontal thermal oxidizers. Vertical thermal oxidizers require a +, 乂 乂 / square inch installation (this is important for some facilities). The available space for capital expansion in existing industrial facilities is often limited and sometimes confusing. Therefore, there are significant advantages in the method of accomplishing a device having a small amount of required space. Due in part to the lower space requirements, the vertical thermal oxidizer can be located closer to the operating hardware of the relevant industrial method. The fittings to the oxidizer are typically of a large diameter, typically more than 30 inches. The thermal oxidizer is located in close proximity to the program, which not only eliminates the capital cost of many linear wickings of expensive large diameter pipe fittings, it also reduces the pressure drop experienced in the connecting pipe. This also allows industrial processes to operate at lower pressures; in some cases, this increases yield efficiency and therefore increases overall product output. The vertical thermal oxidizer/not included in the figure also contains the water-based waste machine 102 that needs to be selected. In this embodiment, the aqueous waste stream 2 is injected into the combustion zone 1 - 2 and contains water and at least one additional waste compound such as acetic acid, cyanide, inorganic salts, benzene, toluene, group clothing, and the like. Additionally, the aqueous waste stream 102 may further comprise one or more other portions of the subject matter industrial process or a waste stream (auxiliary waste) from a completely different process. Although the aqueous waste stream 1 〇 2 is preferably a liquid, it may be a gas or a mixture of a gas and a liquid. The aqueous waste stream 102 may further comprise one or more other portions of the subject matter industrial process or from a completely different process to issue a waste stream (auxiliary aqueous waste)

〇:\88\882!8 DOC 19 1254781)). Examples of such waste streams include, but are not limited to, light ends waste from ethyl acrylate procedures (including ethyl acrylate, ethyl acetate and water) and waste ester distillates from methacrylate procedures (including methacrylic acid) Oxime ester, methanol and water). In some embodiments, it may be advantageous to mix the aqueous waste stream with the oxidant 110 or fuel 11 2 prior to injection into the combustion zone 122. Those skilled in the art will also appreciate that it is possible to reduce the burning fuel demand in the thermal oxidizer if the optional aqueous waste stream 1 〇 2 has a positive net calorific value. The waste stream 114 and the supplemental oxidant stream 11 7 are combined in the waste destruction zone inlet official line 11 8 ' and then connected to one or more waste destruction zone injection points 27 . The supplemental oxidant stream 117 can have the same composition as the oxidant 110 or can have a higher or lower oxygen content. In some embodiments, oxidant stream 110 can comprise atmospheric air, and supplemental oxidant stream 117 can comprise an oxygen-containing process vent gas. The waste oxidant stream from inlet line 118 is injected into waste destruction zone 124 of thermal oxidizer 120 via injection point 127. The injection point m can be radially clamped along the outer surface of the thermal oxidizer 120 adjacent to the waste destruction zone 124, or in some other structure that promotes uniform mixing in the waste destruction zone. Each injection point 127 provides a supply of premixed waste stream 114 and a supplemental oxidant stream 7. The premixed waste stream 114 and the supplemental oxidant stream 117 increase the efficiency of the destruction and also reduce the number of injection ports required. The fewer injection ports reduce the size required for the waste destruction zone 124 as well as the thermal oxidizer 1 20 and the overall size and point too - Gan & In some cases, it may be advantageous to inject the waste stream 114 and the supplemental oxidant stream 117 independently into the waste destruction zone 124 or possibly completely omitting the use of the supplemental oxidant stream 117.

O:\88\88218.DOC -20- 1254781 Waste stream 11 4 usually contains components or waste streams that are to be destroyed by industrial methods from 1 Fenggu^, Zhongmu 3 wood. The waste stream m may comprise a gas, a liquid or a mixture of the two, and may also contain inert ingredients such as water, diatomic nitrogen or carbon dioxide. The true composition of the waste stream 114 will depend on the particular I industry method considered, but must include at least a minimum amount of reactive waste constituents. Examples of such reactive waste components include, but are not limited to, aliphatic hydrocarbons, acrolein, hydrogen, hydrogen cyanide, oxidized stone, urea, and aromatics. While such compounds may contain oxygen atoms as part of their structure (e. g., carbon monoxide), oxygen-free compounds are generally preferred. The waste stream injected into the downstream waste destruction zone preferably comprises at least 〇·5 mole % reactive waste constituents or no more than 99·5 mole % inert constituents, and 俾 effectively reduces WOG emissions. The waste stream is particularly good for at least 2 moles. /〇Reactive waste ingredients or no more than 98% by mole of inert ingredients. Industrial chemical processes relating to vertical embodiments of thermal oxidizers can include the production of hydrogen cyanide, acrylic acid, acrylic acid, acrylonitrile, methacrylonitrile, methacrolein, methacrylic acid, anhydride anhydride, maleic anhydride and The method of the mixture. In some embodiments, it is contemplated that the primary shot auxiliary waste flows to the thermal oxidizer via a dedicated injection point or by mixing auxiliary waste in the waste stream 4 (or additionally in the supplement waste stream 7).丨 2〇 may be advantageous. The auxiliary waste stream contains waste streams that can be emitted from another part of the subject industrial process or from a completely different process. Such auxiliary waste streams may or may not contain a large amount of reactive waste constituents and may further comprise solids, liquids, gases or mixtures of two or more thereof. Examples of such auxiliary waste include, but are not limited to, recovered spent fuel, organically contaminated wastewater, process venting, polymer solids, or mineral acid residues.

O:\88\88218.DOC -21 - 1254781 In the case where a large amount of liquid waste constituents are present in a given waste stream, for example, when the waste stream contains organically contaminated waste water, it is preferred that at least a portion of the liquid waste component is injected into the heat. The upstream zone of the oxidizer. This upstream injection maximizes the residence time and thus increases the efficiency of waste destruction. It is particularly preferred that the liquid forming knives are at least partially injected into the primary combustion zone. As described above with respect to the horizontal thermal oxidizer 20, at least a portion of the reactive waste component injected into the vertical thermal oxidizer 12 is converted to a reducing group in the waste destruction zone 1 24 . The reactive group is then reacted with the spent oxidizing gas present in the waste destruction zone to reduce the WOG emissions from the waste destruction process. The effluent leaving the waste destruction zone 124 passes through the effluent stack 13 (where it is directed to the atmosphere). Depending on the situation, the effluent 1 3 2 may be directed through a heat recovery steam boiler (HR SG) 128 or other heat recovery unit to recover some of the heat contained in the effluent 1 3 2 before entering the effluent fumes 13⁄4 13 〇. . The heat recovery by the autothermal oxidizer is steam, and the heat recovery of the effluent 1 32 improves the energy efficiency of the total waste destruction process. EXAMPLES Referring now to the method architecture of Figure 1, an example is provided to illustrate the specific and improved features of the present invention. This particular embodiment relates to a method of producing acrylic acid. For purposes of illustration, the thermal oxidizer 20 illustrated in Figure 1 will be described with reference to its industrial chemical process for the production of acrylic acid (catalytic oxidation reaction via propylene). However, the methods of the present invention can be used in other industrial processes, and the following examples are not intended to limit the scope of the invention in any way. Example 1 -22-

O:\88\88218 DOC 1254781 In the industrial chemical process for the manufacture of acrylic acid from propylene feed, the waste stream is treated using a two-stage thermal oxidizer of the type shown in Figure 1. The furnace zone of the thermal oxidizer (from the point of addition 21 to the waste destruction zone 26) is about 5.9 meters (7 inches) long. The primary waste destruction zone 24 has an inner diameter of 18 meters (6 inches) and the secondary waste destruction zone 26 has an inner diameter of 3.2 meters (1 inch 5 inches). The base load enthalpy of the thermal oxidizer was determined according to the following: • Natural gas from commercial pipelines was used as the combustion fuel stream 12 and injected into the primary combustion zone at a rate of 24,525 liters per minute (866 scfm). Ambient temperature Atmosphere Air is used as the oxidant stream 10 . The air stream was injected into the primary combustion zone 22 at a rate of 31 Torr, 387 liters per minute (1 〇, 960 scfm) and injected into the secondary waste destruction zone at a rate of 31 Torr, 387 liters per minute (10,960 scfm). The furnace temperature averaged 818 ° C (1 505 〇 F), and the soot) 33 oxygen content (measured as wet basis) was 13 mol / 〇. / A waste stream is supplied to the incinerator (the flow rate of the waste stream 4 is 〇), and the NOx emission rate of the base load is determined to be mwo-o4 mg n〇x/+ (〇〇84 lb NOx/MM BTU) 〇 Comparative Example 1 In the same industrial chemical process for producing acrylic acid from propylene feed and using the same level two-stage thermal oxidizer as in Example 1, the operation of the thermal oxidizer was adjusted according to the method of the present invention, and the reduced cesium emissions were captured. . Natural gas from commercial lines was used as the combustion fuel stream 12 and injected into the primary combustion zone at a rate of 36,306 liters per minute (1282 scfm). Ambient temperature Atmospheric air is used as the oxidant stream 1 注入 and is injected into the primary combustion zone 22 at a rate of 6 4 6 2 2 2 liters per minute (22,820 scfm) at a rate of 43 丨...(10) liters / minute ( 1 5,220 scfm) is injected into the secondary waste destruction zone 26. The average temperature of the atheroma O:\88\88218 DOC -23 - 1254781 is 862t (1 583. 〇, and (4) 33 oxygen content (measured as wet basis) is 3 mol%. 6 (TC(10).F) contains 98 Mo Ear % inerts f (eg nitrogen, water, carbon dioxide, oxygen and argon), 9.9 mol % aliphatic hydrocarbons (eg propane, propane) and 1" mol% other reactive waste components (eg - oxidation A gaseous waste stream 14 of carbon, acetic acid, acrolein, etc. is provided in the incinerator, thereby generating a poor-reactive component feed concentration of 2 mol%. The waste (four) is divided into two parts at the tee: the first part At a rate of 658,723 liters/min (7)·scfm) into the primary waste destruction zone via a twelve-hole distributor (about G.76 meters downstream of the emulsifier injection point 21 (25 py points _); The rate is 329,362 liters / minute (1), 63% (four) through the 30-hole surrounding distributor into the secondary waste destruction zone (at the injection point of about 0.76 meters (2.5 feet) at the oxidant entry point Ml The emission rate of cockroaches generated by the household is determined to be 7.2 χ 1 〇 ΰ 5 mg Ν〇χ / card (four) Ν〇χ / ΜΜ BTU), gj and Ν〇 The enthalpy emission reduction rate exceeded the catch (compared to the base load case of Example 1). Thus, the process of the present invention has been found to provide significantly reduced w〇G emissions from the waste discharge process. Accordingly, the invention as described herein is capable of the a Although: the purpose of the month has provided a number of presently preferred embodiments of the present invention, it is possible to achieve a number of changes in the desired results. For example, the invention may involve the manufacture of an industrial process waste stream containing waste destruction as part of the process. Furthermore, it will be confirmed that the present invention is particularly suitable for the treatment of industrial chemical T-process waste, for example, in the manufacture of (meth) propylene, hydrogen cyanide, (meth)acrylonitrile, (meth)acrylic acid, sulphuric acid, Maleic anhydride and other similar products

O:\88\88218 D0C -24- 1254781 Produced in the process. Moreover, it is conceivable in certain embodiments that it may be advantageous to incorporate prior art WOG emission reduction techniques (e.g., NOx burners and selection/original systems) with the method according to the invention. These and other similar modifications are readily apparent to those skilled in the art and are intended to be included within the scope of the invention. & BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a specific example of the present invention when applied to a horizontal multi-stage thermal oxidizer. Fig. 2 is a view showing another embodiment of the present invention when applied to a vertical multi-stage thermal oxidizer. [Illustration of symbolic representation] 10 oxidant stream 11 tee 12 combustion fuel stream 13 supplement oxidant stream 14 waste stream 15 tee 17 supplementary waste stream 20 thermal oxidizer 21 oxidant addition point 22 primary combustion zone 24 primary waste destruction zone 25 First waste destruction zone waste stream addition point

O:\88\88218 DOC secondary waste destruction zone heat recovery steam boiler effluent chimney addition point effluent chimney

Aqueous waste stream oxidant stream combustion fuel waste stream

Supplemental oxidant flow Waste destruction zone inlet line Thermal oxidizer Waste destruction zone Waste destruction zone injection point Heat recovery steam boiler Effluent chimney Effluent -26-

Claims (1)

1254781 Pickup, patent application scope: It includes the following steps to reduce the emission of waste oxide gases in industrial processes: burning at least a portion of the waste a. directing the waste stream to the thermal oxidizer; b · primary at the thermal oxidizer a combustion zone flow; and c. injecting at least a portion of the waste stream into the downstream waste destruction zone. 2. The method of claim </RTI> wherein the waste stream comprises at least about 0.5 mole percent of reactive waste components and up to about 99 5 mole percent inert components. 3. If the patent application method is included, it also includes the supply of alkaline waste to the primary combustion zone. 4. The method of claim 1, wherein the method further comprises supplying auxiliary waste to the downstream waste destruction zone, wherein the auxiliary waste is selected from the group consisting of aqueous waste and alternative waste. 5. The method of claim 1, wherein the product produced by the industrial process is selected from the group consisting of acrylic acid, methacrylic acid, acrolein, mercapto acrolein, hydrogen cyanide, acrylonitrile, mercapto acrylonitrile, hydrazine. A group of anhydrides, maleic anhydride, and mixtures thereof. 6 - A method for reducing the emission of waste oxide gases in industrial chemical processes, the industrial chemical process being selected from the group consisting of methacrylic acid, acrolein, methacrolein, hydrogen cyanide, acrylonitrile, mercapto acrylonitrile, phthalic anhydride a product of a group consisting of maleic anhydride and mixtures thereof, the process comprising the steps of: O:\88\88218.DOC 1254781 a. directing the waste stream to a horizontal thermal oxidizer; b_ primary combustion of the thermal oxidizer Burning at least a part of the waste stream in the area; and X/Eight-eight main bad area# The waste stream is broken in the downstream of the thermal oxidizer. 7. As in the method of claim 6, the _ at least - the waste stream contains At least kiss. The reactive waste component and up to about 99 5 mole % of the inert component. 8. If the method of applying for the sixth paragraph of the patent scope, the method of the Tuganshan, it is included in the primary combustion zone. [10] 9. If you apply for the patent, the sixth paragraph of the ancient, soil * method, which also contains the supply of auxiliary waste in the waste under the waste of the waste area, φ soil U Shiyan, Hai auxiliary waste system Choose free water-based waste and replace the group of waste. , Putian &gt; I Wangwei and O:\88\882i8.DOC