Coal combustion aids, methods of making, using and coal combustion

Abstract

The application relates to a coal combustion aid, a preparation method and application thereof, and coal. Components of the coal combustion aid include depolymerization kettle bottom liquid, a catalyst and an oxidizing agent; the depolymerization kettle bottom liquid includes depolymerization kettle bottom liquid of at least one of acrylic acid heavy component and butyl acrylate heavy component. The coal combustion aid can effectively reduce an ignition point of coal, reduce a burnout point of coal, and improve a combustion efficiency of coal through mutual cooperation of the components. Meanwhile, the coal combustion aid can effectively utilize the acrylic acid heavy component and the butyl acrylate heavy component, improve economic benefits, and be beneficial to environmental protection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resource recycling, in particular to a coal combustion aid, a preparation method, application and coal combustion thereof. BACKGROUND

[0002] Acrylic acid and butyl acrylate are widely used in industry as chemical raw materials. Industrial acrylic acid and butyl acrylate are prepared by distillation using crude acrylic acid and crude butyl acrylate as raw materials, respectively. In the process of distillation production, with continuous distillation, acrylic acid heavy components mainly composed of acrylic acid polymers and butyl acrylate heavy components mainly composed of butyl acrylate polymers are continuously accumulated in the tower kettle.

[0003] The treatment method of acrylic acid heavy components and butyl acrylate heavy components is generally direct incineration, which can cause environmental pollution and waste of energy.

[0004] Coal is mainly used in power generation, cement, metallurgy and chemical industries. With the continuous development of industrialization, people's demand for coal is increasing. However, coal is a non-renewable resource and its combustion process can easily cause air pollution. Therefore, improving the combustion efficiency of coal can not only reduce costs and generate certain economic benefits, but also reduce air pollution and generate good social benefits. SUMMARY

[0005] Therefore, it is necessary to provide a coal combustion aid that can improve the combustion efficiency of coal and effectively utilize acrylic acid heavy components and butyl acrylate heavy components. Further, a preparation method, application and coal combustion of the coal combustion aid are provided.

[0006] The first aspect of the present application provides a coal combustion aid, which comprises a depolymerization kettle bottom liquid, a catalyst and an oxidizing agent; the depolymerization kettle bottom liquid comprises a depolymerization kettle bottom liquid of at least one of acrylic acid heavy components and butyl acrylate heavy components.

[0007] The coal combustion aid uses the depolymerization kettle bottom liquid of at least one of acrylic acid heavy components and butyl acrylate heavy components, a catalyst and an oxidizing agent as raw materials, and the components synergize with each other to effectively reduce the ignition point of coal and the burnout point of coal, thereby improving the combustion efficiency of coal. At the same time, acrylic acid heavy components and butyl acrylate heavy components can be effectively utilized, economic benefits can be improved, and environmental protection can be facilitated.

[0008] Further, after depolymerization, the remaining or light components obtained after depolymerization are basically evaporated and discharged, and only the heavy components remain in the kettle bottom liquid. The kettle bottom liquid can provide the heat value required by the coal combustion aid itself as the mother liquor of the coal combustion aid. In addition, after the light components are evaporated, the kettle bottom liquid can be solidified, further improving the stability of the coal combustion aid.

[0009] In some embodiments, the depolymerization kettle bottom liquid comprises, by mass percentage, 0-98% of a polymer of acrylic acid, 1-14% of maleic anhydride, 0-99% of a polymer of butyl acrylate, and 0-5% of butoxy butyl propionate; and the polymer of acrylic acid and the polymer of butyl acrylate are not both 0.

[0010] In some embodiments, the coal combustion aid satisfies one of the following conditions:

[0011] (1) the depolymerization kettle bottom liquid comprises, by mass percentage, 85-98% of a polymer of acrylic acid and 1-10% of maleic anhydride;

[0012] (2) the depolymerization kettle bottom liquid comprises, by mass percentage, 90-99% of a polymer of butyl acrylate, 0-5% of butoxy butyl propionate, and 0-4% of maleic anhydride;

[0013] (3) the depolymerization kettle bottom liquid comprises, by mass percentage, 25-72% of a polymer of acrylic acid, 1-2% of maleic anhydride, 24-75% of a polymer of butyl acrylate, and 0-5% of butoxy butyl propionate.

[0014] In some embodiments, the coal combustion aid comprises, by mass fraction, 50-85 parts of the depolymerization kettle bottom liquid, 1-30 parts of an oxidizing agent, and 1-20 parts of a catalyst.

[0015] In some embodiments, the coal combustion aid further comprises, by mass fraction, 5-10 parts of an alkaline inorganic filler.

[0016] In some embodiments, the coal combustion aid comprises, by mass fraction, 75-85 parts of the depolymerization kettle bottom liquid, 1-10 parts of an oxidizing agent, 1-5 parts of a catalyst, and 5-10 parts of an alkaline inorganic filler.

[0017] In some embodiments, the coal combustion aid satisfies at least one of the following conditions:

[0018] (1) the oxidizing agent is a metal salt;

[0019] (2) the catalyst is a metal oxide;

[0020] (3) the alkaline inorganic filler is selected from at least one of calcium oxide, calcium hydroxide, sodium hydroxide, and potassium hydroxide.

[0021] In some embodiments, the coal combustion aid satisfies at least one of the following conditions:

[0022] (1) the oxidizing agent is selected from at least one of potassium permanganate, sodium nitrate, potassium nitrate, and potassium chlorate;

[0023] (2) the catalyst is selected from at least one of aluminum oxide, manganese dioxide, magnesium oxide and ferric oxide.

[0024] The second aspect of the present application provides a preparation method of the coal combustion aid, comprising the following steps:

[0025] The depolymerization kettle bottom liquid, the catalyst and the oxidant are mixed.

[0026] In some embodiments, the preparation method of the depolymerization kettle bottom liquid comprises:

[0027] At least one of the acrylic acid heavy component and the butyl acrylate heavy component is subjected to a depolymerization reaction under the action of an acidic catalyst to obtain a kettle bottom liquid; the pressure of the depolymerization reaction is-0.09 MPa to 0.05 MPa, the temperature is 100℃ to 350℃, and the time is 5h to 15h.

[0028] In some embodiments, the acidic catalyst is selected from at least one of methyl sulfonic acid, p-toluene sulfonic acid and sulfuric acid.

[0029] In some embodiments, the method further comprises the following steps:

[0030] After the depolymerization kettle bottom liquid, the catalyst and the oxidant are mixed, the obtained mixture is subjected to heat preservation for 5min to 10min under the condition that the vacuum air pressure is 20KPa to 50KPa and the temperature is 180℃ to 200℃.

[0031] The third aspect of the present application provides an application of the coal combustion aid of the first aspect in the preparation of coal.

[0032] The fourth aspect of the present application provides a coal, comprising a coal base material and the coal combustion aid of the first aspect.

[0033] In some embodiments, the mass percentage content of the coal combustion aid in the coal is 0.2% to 0.5%. DETAILED DESCRIPTION

[0034] In order to facilitate the understanding of the present application, the present application will be described more fully below, and the preferred embodiments of the present application are given. However, the present application can be realized in many different forms, and is not limited to the embodiments described herein. It should be understood that the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0036] In addition, the terms "first", "second", etc. are used herein only to describe various conditions, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0037] The coal combustion aid is an additive that can promote the complete combustion of coal, play a role in combustion, energy increase, and coal saving, can reduce harmful gas emissions, protect the environment, reduce enterprise production cost, and bring huge economic benefits to enterprises. Compared with solid coal combustion aids, liquid coal combustion aids have higher requirements for sealing in terms of storage and transportation; and liquid coal combustion aids are prone to deterioration or risk of combustion and explosion due to temperature, humidity, vibration, etc.

[0038] In an embodiment of the present application, a coal combustion aid is provided, which comprises a depolymerization kettle bottom liquid, a catalyst and an oxidizing agent; the depolymerization kettle bottom liquid comprises at least one of a depolymerization kettle bottom liquid of an acrylic acid heavy component and a butyl acrylate heavy component.

[0039] It can be understood that the above-mentioned depolymerization kettle bottom liquid comprises a first depolymerization kettle bottom liquid obtained after depolymerization of an acrylic acid heavy component, or a second depolymerization kettle bottom liquid obtained after depolymerization of a butyl acrylate heavy component, or a third depolymerization kettle bottom liquid obtained after depolymerization of a mixture of the acrylic acid heavy component and the butyl acrylate heavy component, or a mixed liquid comprising the first depolymerization kettle bottom liquid and the second depolymerization kettle bottom liquid.

[0040] The above-mentioned coal combustion aid uses the depolymerization kettle bottom liquid of at least one of the acrylic acid heavy component and the butyl acrylate heavy component, the catalyst and the oxidizing agent as raw materials for preparation, and the components synergize with each other, which can effectively reduce the ignition point of coal and the burnout point of coal, and improve the combustion efficiency of coal. At the same time, the acrylic acid heavy component and the butyl acrylate heavy component can be effectively utilized, the economic benefit is improved, and the environment is protected.

[0041] Further, after the recombination components are depolymerized, the remaining or the depolymerized light components are substantially evaporated and discharged, and only the heavy components remain in the kettle bottom liquid. The kettle bottom liquid can be used as a coal combustion additive mother liquor to provide the heat value required by the coal combustion additive itself. In addition, the kettle bottom liquid can be solidified after the light components are evaporated, further improving the stability of the coal combustion additive.

[0042] In some embodiments, the acrylic acid heavy component is a kettle bottom liquid component of acrylic acid prepared by oxidation of propylene.

[0043] In some embodiments, the acrylic acid heavy component includes, by mass percentage, 0-1% propionic acid, 0-30% acrylic acid, 1%-25% β-(acryloyloxy)propionic acid, 1%-5% maleic anhydride, and 40%-80% acrylic acid polymer.

[0044] In some embodiments, the butyl acrylate heavy component is a kettle bottom liquid component of crude butyl acrylate obtained by esterification of acrylic acid and n-butanol under the action of an acidic catalyst in a rectification process.

[0045] In some embodiments, the butyl acrylate heavy component includes, by mass percentage, 0-2% butanol, 0-20% butyl acrylate, 5%-30% butoxy butyl acrylate, 0-2% hydroxy butyl acrylate, 0-5% propoxy butyl acrylate, 0-2% maleic anhydride, and 40%-80% butyl acrylate polymer.

[0046] In some embodiments, the depolymerization kettle bottom liquid includes, by mass percentage, 0%-98% acrylic acid polymer, 1%-14% maleic anhydride, 0%-99% butyl acrylate polymer, and 0-5% butoxy butyl acrylate; the acrylic acid polymer and the butyl acrylate polymer are not both 0.

[0047] In some embodiments, the depolymerization kettle bottom liquid includes a third depolymerization kettle bottom liquid obtained by depolymerization of a mixture of the acrylic acid heavy component and the butyl acrylate heavy component, wherein the mass ratio of the acrylic acid heavy component to the butyl acrylate heavy component in the mixture is (0.1-10):1. Preferably, the mass ratio of the acrylic acid heavy component to the butyl acrylate heavy component in the mixture is (0.3-3):1.

[0048] In some embodiments, the depolymerization kettle bottom liquid comprises a mixture of a first depolymerization kettle bottom liquid and a second depolymerization kettle bottom liquid, wherein the mass ratio of the first depolymerization kettle bottom liquid to the second depolymerization kettle bottom liquid is (0.1-10): 1. As an example, the mass ratio of the first depolymerization kettle bottom liquid to the second depolymerization kettle bottom liquid can be 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.8:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. Further, the mass ratio of the first depolymerization kettle bottom liquid to the second depolymerization kettle bottom liquid can be any other ratio within the above range. Preferably, the mass ratio of the first depolymerization kettle bottom liquid to the second depolymerization kettle bottom liquid is (0.8-2): 1.

[0049] In some embodiments, the depolymerization kettle bottom liquid comprises, by mass percentage, 85-98% of a polymer of acrylic acid and 1-10% of maleic anhydride.

[0050] In some embodiments, the depolymerization kettle bottom liquid comprises, by mass percentage, 90-99% of a polymer of butyl acrylate, 0-5% of butoxy butyl propionate, and 0-4% of maleic anhydride.

[0051] In some embodiments, the depolymerization kettle bottom liquid comprises, by mass percentage, 25-72% of a polymer of acrylic acid, 1-2% of maleic anhydride, 24-75% of a polymer of butyl acrylate, and 0-5% of butoxy butyl propionate.

[0052] In some embodiments, the oxidizing agent is a metal salt. Further, the metal salt oxidizing agent is selected from at least one of potassium permanganate, sodium nitrate, potassium nitrate, and potassium chlorate. Preferably, the metal salt oxidizing agent is potassium nitrate.

[0053] In some embodiments, the catalyst is a metal oxide. Further, the metal oxide catalyst is selected from at least one of aluminum oxide, manganese dioxide, magnesium oxide, and iron sesquioxide. Preferably, the metal oxide catalyst is manganese dioxide.

[0054] In some embodiments, the coal combustion aid comprises, by mass parts, 50-85 parts of the depolymerization kettle bottom liquid, 1-30 parts of the oxidizing agent, and 1-20 parts of the catalyst. The depolymerization kettle bottom liquid in the present embodiments refers to at least one of a depolymerization kettle bottom liquid comprising a mixture of the acrylic acid heavy component and the butyl acrylate heavy component, a depolymerization kettle bottom liquid of the acrylic acid heavy component, and a depolymerization kettle bottom liquid of the butyl acrylate heavy component.

[0055] As an example, the mass fraction of the depolymerization kettle bottom liquid in the coal combustion aid can be 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 73 parts, 75 parts, 78 parts, 80 parts, 82 parts, or 85 parts. Further, the mass fraction of the depolymerization kettle bottom liquid can be a range value formed by any two point values above as end values. Preferably, the mass fraction of the depolymerization kettle bottom liquid is 75 parts to 85 parts.

[0056] As an example, the mass fraction of the oxidizing agent in the coal combustion aid can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 25 parts, or 30 parts. Further, the mass fraction of the oxidizing agent can be a range value formed by any two point values above as end values. Preferably, the mass fraction of the oxidizing agent is 1 part to 10 parts.

[0057] As an example, the mass fraction of the catalyst in the coal combustion aid can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 15 parts, 18 parts, or 20 parts. Further, the mass fraction of the catalyst can be a range value formed by any two point values above as end values. Preferably, the mass fraction of the catalyst is 1 part to 5 parts.

[0058] In some embodiments, the coal combustion aid includes 50 parts to 85 parts of the depolymerization kettle bottom liquid, 1 part to 30 parts of the oxidizing agent, and 1 part to 20 parts of the catalyst, and further includes 5 parts to 10 parts of the alkaline inorganic filler. Adding the alkaline inorganic filler in the coal combustion aid can improve the strength of the solid coal combustion aid, reduce the surface adhesion, and can neutralize the acidic substances in the components, improve the pH value of the system, reduce the acidity of the system, and reduce the corrosion to the equipment.

[0059] In some embodiments, the mass fraction of the inorganic filler in the coal combustion aid can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts. Further, the mass fraction of the inorganic filler can be a range value formed by any two point values above as end values.

[0060] In some embodiments, the alkaline inorganic filler is selected from at least one of calcium oxide, calcium hydroxide, sodium hydroxide, and potassium hydroxide. Preferably, the alkaline inorganic filler is calcium oxide. The calcium oxide can neutralize the acrylic acid to generate calcium salt, and reduce the acidity of the depolymerization kettle bottom liquid. Meanwhile, the calcium oxide has strong hygroscopicity, can adsorb the internal viscous liquid of the acrylic acid and butyl acrylate, and enhance the strength of the coal combustion aid.

[0061] In some embodiments, the coal combustion aid includes 75 parts to 85 parts of the depolymerization kettle bottom liquid, 1 part to 10 parts of the oxidizing agent, 1 part to 5 parts of the catalyst, and 5 parts to 10 parts of the alkaline inorganic filler in terms of mass fraction.

[0062] In some embodiments, the coal combustion aid includes 75% to 85% of the depolymerization kettle bottom liquid, 1% to 10% of the oxidizing agent, 1% to 5% of the catalyst, and 5% to 10% of the alkaline inorganic filler, by mass percentage.

[0063] In some embodiments, the coal combustion aid is in a solid state at normal temperature. In the present application, the normal temperature refers to a condition of 10°C to 40°C.

[0064] In an embodiment of the present application, a preparation method of the above coal combustion aid is provided, including the following step S10.

[0065] S10, mixing the depolymerization kettle bottom liquid, the catalyst, and the oxidizing agent.

[0066] In some embodiments, the preparation method of the depolymerization kettle bottom liquid includes:

[0067] At least one of the acrylic heavy component and the butyl acrylate heavy component is subjected to a depolymerization reaction under the action of an acidic catalyst to obtain the kettle bottom liquid.

[0068] The acrylic heavy component and the butyl acrylate heavy component have some light components and components with low molecular weight remaining therein, so that the heavy component is in a liquid state. After the depolymerization, the light components can be removed, and part of the polymers can also be decomposed into light components and discharged. At the same time, part of the polymer components can be further polymerized, thereby improving the viscosity of the coal combustion aid, and even making the coal combustion aid tend to be in a solid state.

[0069] In some embodiments, the acidic catalyst is selected from at least one of methyl sulfonic acid, p-toluene sulfonic acid, and sulfuric acid. Preferably, the acidic catalyst is p-toluene sulfonic acid.

[0070] In some embodiments, the addition amount of the acidic catalyst is 1% to 2% of the total mass of the acrylic heavy component and the butyl acrylate heavy component.

[0071] In some embodiments, the pressure of the depolymerization reaction is -0.09 MPa to 0.05 MPa. For example, the pressure of the depolymerization reaction can be -0.09 MPa, -0.06 MPa, -0.05 MPa, -0.03 MPa, 0 MPa, 0.01 MPa, 0.02 MPa, 0.04 MPa, or 0.05 MPa. Further, the pressure of the depolymerization reaction can be a range value formed by any two of the above-mentioned point values as end values. Under the pressure condition, part of the light components remaining after the depolymerization can be separated from the kettle bottom liquid.

[0072] In some embodiments, the temperature of the depolymerization reaction is 100℃ to 350℃. As an example, the temperature of the depolymerization reaction can be 100℃, 150℃, 180℃, 200℃, 220℃, 250℃, 260℃, 280℃, 300℃, 310℃, 320℃, 340℃ or 350℃. Further, the temperature of the depolymerization reaction can be a range value formed by any two of the above-mentioned point values as end values. Preferably, the temperature of the depolymerization reaction is 150℃ to 220℃.

[0073] In some embodiments, the time of the depolymerization reaction is 5h to 15h. As an example, the time of the depolymerization reaction can be 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h or 15h. Further, the time of the depolymerization reaction can be a range value formed by any two of the above-mentioned point values as end values.

[0074] In some embodiments, the above-mentioned preparation method further comprises step S20.

[0075] S20, the mixture obtained in step S10 is kept at a temperature of 180℃ to 200℃ and a vacuum air pressure of 20KPa to 50KPa for 5min to 10min. Keeping the mixture at 20KPa to 50KPa, 180℃ to 200℃ for 5min to 10min can further remove the residual light components in the mixture and improve the viscosity of the coal combustion aid.

[0076] In some embodiments, the above-mentioned step S20 can be carried out in a twin-screw extruder with a vacuum system and a temperature control system.

[0077] In an embodiment of the present application, the use of the above-mentioned coal combustion aid in the preparation of coal is provided.

[0078] In an embodiment of the present application, a preparation method of coal is provided, comprising the following steps:

[0079] Mixing the coal and the coal base material.

[0080] In an embodiment of the present application, a coal is provided, which comprises a coal base material and the above-mentioned coal combustion aid.

[0081] In some embodiments, the mass percentage content of the coal combustion aid in the coal is 0.2% to 0.5%. Preferably, the mass percentage content of the coal combustion aid in the coal is 0.3%.

[0082] In order to make the purpose, technical scheme and advantages of the present application more concise and clear, the present application is described by the following specific examples, but the present application is by no means limited to these examples. The following described examples are only better embodiments of the present application, which can be used to describe the present application, and cannot be understood as limiting the scope of the present application. It should be pointed out that any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0083] In order to better illustrate the present application, the content of the present application is further described below in combination with examples. The following are specific examples.

[0084] The component ratio in the acrylic acid heavy component and the butyl acrylate heavy component used in each embodiment and the comparative example of the present application is shown as follows:

[0085] The acrylic acid heavy component includes 1% of propionic acid, 25% of acrylic acid, 15% of β-(acryloyloxy)propionic acid, 3% of maleic anhydride and 56% of polymer of acrylic acid, in terms of mass percentage.

[0086] The butyl acrylate heavy component includes 2% of butanol, 15% of butyl acrylate, 25% of butoxy butyl propionate, 1% of hydroxy butyl acrylate, 3% of propoxy butyl acrylate, 1% of maleic anhydride and 53% of polymer of butyl acrylate, in terms of mass percentage.

[0087] Preparation example of the depolymerization bottom liquid of the reactor:

[0088] Example 1-1, preparation of the depolymerization bottom liquid 1 of the acrylic acid heavy component and the butyl acrylate heavy component mixture:

[0089] 49 parts of the acrylic acid heavy component and 50 parts of the butyl acrylate heavy component are added to a reaction kettle, 1 part of p-toluenesulfonic acid catalyst is added, stirring is performed to heat to 190°C, and the pressure in the kettle is kept at 0.01 MPa, and the depolymerization reaction is performed for 9h. The oligomer in the kettle is partially depolymerized into light components and evaporated to obtain the depolymerization bottom liquid 1 of the acrylic acid heavy component and the butyl acrylate heavy component mixture; wherein the depolymerization bottom liquid 1 includes 45%wt% of polymer of acrylic acid, 47wt% of butyl acrylate polymer, 3wt% of butoxy butyl propionate and 2wt% of maleic anhydride.

[0090] Example 1-2, preparation of the depolymerization bottom liquid 2 of the acrylic acid heavy component and the butyl acrylate heavy component mixture:

[0091] Add 73 parts of acrylic heavy component, 26 parts of butyl acrylate heavy component to the reaction kettle, then add 1.0 part of p-toluene sulfonic acid catalyst, stir to warm up to 210℃, and keep the pressure in the kettle at 0.01 MPa, and carry out depolymerization reaction for 10 h. The oligomers in the kettle are partially depolymerized into light components and evaporated to obtain butyl acrylate heavy component depolymerization kettle bottom liquid 2; wherein, the butyl acrylate heavy component depolymerization kettle bottom liquid 2 includes 2wt% of butoxy butyl propionate, 2wt% of maleic anhydride, 69% of acrylic acid polymer and 24wt% of butyl acrylate polymer.

[0092] Example 1-3, Preparation of depolymerization kettle bottom liquid 3 of acrylic acid heavy component and butyl acrylate heavy component mixture:

[0093] Add 29 parts of acrylic acid heavy component, 69 parts of butyl acrylate heavy component to the reaction kettle, then add 2.0 parts of p-toluene sulfonic acid catalyst, stir to warm up to 210℃, and keep the pressure in the kettle at -0.01 MPa, and carry out depolymerization reaction for 10 h. The oligomers in the kettle are partially depolymerized into light components and evaporated to obtain butyl acrylate heavy component depolymerization kettle bottom liquid 3; wherein, the butyl acrylate heavy component depolymerization kettle bottom liquid 3 includes 25wt% of acrylic acid polymer, 2wt% of maleic anhydride and 70wt% of butyl acrylate polymer.

[0094] Example 1-4, Preparation of butyl acrylate heavy component depolymerization kettle bottom liquid 4:

[0095] Add 99 parts of butyl acrylate heavy component to the reaction kettle, then add 1 part of p-toluene sulfonic acid catalyst, stir to warm up to 150℃, and keep the pressure in the kettle at -0.08 MPa, and carry out depolymerization reaction for 6 h. The oligomers in the kettle are partially depolymerized into light components and evaporated to obtain butyl acrylate heavy component depolymerization kettle bottom liquid 4; wherein, the butyl acrylate heavy component depolymerization kettle bottom liquid 4 includes 3wt% of maleic anhydride and 94wt% of butyl acrylate polymer.

[0096] Example 1-5, Preparation of butyl acrylate heavy component depolymerization kettle bottom liquid 5:

[0097] Add 99 parts of butyl acrylate heavy component to the reaction kettle, then add 1.0 part of p-toluene sulfonic acid catalyst, stir to warm up to 190℃, and keep the pressure in the kettle at -0.02 MPa, and carry out depolymerization reaction for 8 h. The oligomers in the kettle are partially depolymerized into light components and evaporated to obtain butyl acrylate heavy component depolymerization kettle bottom liquid 5; wherein, the butyl acrylate heavy component depolymerization kettle bottom liquid 5 includes 1wt% of butoxy butyl propionate, 1% of maleic anhydride and 94wt% of butyl acrylate polymer.

[0098] Example 1-6, Preparation of butyl acrylate heavy component depolymerization kettle bottom liquid 6:

[0099] 99 parts of butyl acrylate heavy component were added to the reactor, followed by 1.0 part of p-toluenesulfonic acid catalyst. The mixture was stirred and heated to 210°C, while maintaining the pressure inside the reactor at 0.01 MPa, for a depolymerization reaction for 10 hours. The oligomers inside the reactor partially depolymerized into lighter components and were distilled off, yielding butyl acrylate recombinant decomposition polymer bottom liquid 6. This bottom liquid 6 contained 2 wt% butyl butoxypropionate, 1 wt% maleic anhydride, and 93 wt% butyl acrylate polymer.

[0100] Example 1-7, Preparation of acrylic acid recombination decomposition bottom liquid 7:

[0101] 99 parts of heavy acrylic acid were added to the reactor, followed by 1.0 part of p-toluenesulfonic acid catalyst. The mixture was stirred and heated to 190°C, while maintaining a pressure of 0.01 MPa inside the reactor for 9 hours of depolymerization. The oligomers inside the reactor partially depolymerized into lighter components and were distilled off, yielding acrylic acid repolymerization decomposition reactor bottom liquid 7. This bottom liquid 7 contained 91 wt% acrylic acid polymer and 5 wt% maleic anhydride.

[0102] The composition of the depolymerization bottom solution prepared in each example is shown in Table 1.

[0103] Table 1

[0104]

[0105] Examples of the application of coal combustion additives:

[0106] Example 1

[0107] (1) According to the mass ratio: 83wt% acrylic acid recombinant decomposition polymer bottom liquid, 7.5wt% calcium oxide powder, 10wt% potassium nitrate oxidant and 2wt% manganese dioxide catalyst, weigh the raw material components.

[0108] (2) Under mechanical stirring, slowly add 5 wt% calcium oxide powder to the bottom liquid of 83 wt% acrylic acid recombination decomposition polymer at 160℃~180℃ and continue stirring for 1.5h; then slowly add 10 wt% potassium nitrate oxidant and continue stirring for 2h; then slowly add 2 wt% manganese dioxide catalyst and continue stirring for 1h.

[0109] (3) After mixing, the above mixture is fed into a twin-screw extruder with a vacuum system and a temperature control system while it is still hot. The vacuum pressure of the twin-screw extruder is set to 20 kPa. In the heating section of the twin-screw extruder, the material is heated to 180°C within 7 minutes and then kept at a constant temperature for 6 minutes. In the cooling section, the material is cooled to 80°C within 6 minutes to obtain a solid coal combustion additive.

[0110] (4) The solid coal combustion aid is mixed with the coal sample at a mass ratio of 0.3:99.7 to obtain the coal combustion aid added coal.

[0111] Example 2

[0112] (1) The raw material components are weighed according to the mass ratio: 83wt% of butyl acrylate heavy component depolymerization reactor bottom liquid, 5wt% of calcium oxide powder, 10wt% of potassium nitrate oxidant, and 2wt% of manganese dioxide catalyst.

[0113] (2) 5wt% of calcium oxide powder is slowly added to 83wt% of butyl acrylate heavy component depolymerization reactor bottom liquid at 160-180°C under mechanical stirring, and stirring is continued for 1.5h; then 10wt% of potassium nitrate oxidant is slowly added, and stirring is continued for 2h; then 2wt% of manganese dioxide catalyst is slowly added, and stirring is continued for 1h.

[0114] (3) After stirring is completed, the above mixture is sent into a double screw extruder with a vacuum system and a temperature control system while hot, wherein the vacuum pressure of the double screw extruder is set to 30KPa; in the heating section of the double screw extruder, the material is heated to 200°C within 8min, and then constant temperature is maintained for 7min; in the cooling section, the material is cooled to 90°C within 10min, to obtain a solid coal combustion aid.

[0115] (4) The solid coal combustion aid is mixed with the coal sample at a mass ratio of 0.3:99.7 to obtain the coal combustion aid added coal.

[0116] Example 3

[0117] (1) The raw material components are weighed according to the mass ratio: 83wt% of butyl acrylate heavy component depolymerization reactor bottom liquid, 5wt% of calcium oxide powder, 10wt% of potassium nitrate oxidant, and 2wt% of manganese dioxide catalyst.

[0118] (2) 5wt% of calcium oxide powder is slowly added to 83wt% of butyl acrylate heavy component depolymerization reactor bottom liquid at 160-180°C under mechanical stirring, and stirring is continued for 1.5h; then 10wt% of potassium nitrate oxidant is slowly added, and stirring is continued for 2h; then 2wt% of manganese dioxide catalyst is slowly added, and stirring is continued for 1h.

[0119] (3) After stirring is completed, the above mixture is sent into a double screw extruder with a vacuum system and a temperature control system while hot, wherein the vacuum pressure of the double screw extruder is set to 30KPa; in the heating section of the double screw extruder, the material is heated to 200°C within 8min, and then constant temperature is maintained for 7min; in the cooling section, the material is cooled to 90°C within 10min, to obtain a solid coal combustion aid.

[0120] (4) The solid coal combustion aid is mixed with the coal sample in a mass ratio of 0.3:99.7 to obtain coal combustion aid added coal.

[0121] Example 4

[0122] (1) The raw material components are weighed according to the mass ratio: 83wt% of butyl acrylate heavy component depolymerization reactor bottom liquid 5, 5wt% of calcium oxide powder, 10wt% of potassium nitrate oxidizing agent, and 2wt% of manganese dioxide catalyst.

[0123] (2) 5wt% of calcium oxide powder is slowly added to 83wt% of butyl acrylate heavy component depolymerization reactor bottom liquid 5 at 160°C-180°C under mechanical stirring, and stirring is continued for 1.5h; then 10wt% of potassium nitrate oxidizing agent is slowly added, and stirring is continued for 2h; then 2wt% of manganese dioxide catalyst is slowly added, and stirring is continued for 1h.

[0124] (3) After stirring is completed, the above mixture is hot fed into a double screw extruder with a vacuum system and a temperature control system, wherein the vacuum pressure of the double screw extruder is set to 45KPa; in the heating section of the double screw extruder, the material is heated to 200°C within 8min, and then constant temperature is maintained for 7min; in the cooling section, the material is cooled to 90°C within 10min, to obtain a solid coal combustion aid.

[0125] (4) The solid coal combustion aid is mixed with the coal sample in a mass ratio of 0.3:99.7 to obtain coal combustion aid added coal.

[0126] Example 5

[0127] The preparation method of this example is basically the same as that of Example 2, the only difference being that the components of the depolymerization reactor bottom liquid in this example are different, and the depolymerization reactor bottom liquid used in this example is butyl acrylate heavy component depolymerization reactor bottom liquid 6. The other steps are basically the same as those of Example 1.

[0128] Example 6

[0129] (1) The raw material components are weighed according to the mass ratio: 80wt% of butyl acrylate heavy component depolymerization reactor bottom liquid 4, 5wt% of calcium oxide powder, 10wt% of potassium nitrate oxidizing agent, and 5wt% of manganese dioxide catalyst.

[0130] (2) 5wt% of calcium oxide powder is slowly added to 83wt% of butyl acrylate heavy component depolymerization reactor bottom liquid 4 at 160°C-180°C under mechanical stirring, and stirring is continued for 1.5h; then 10wt% of potassium nitrate oxidizing agent is slowly added, and stirring is continued for 2h; then 5wt% of manganese dioxide catalyst is slowly added, and stirring is continued for 1h.

[0131] (3) After the stirring is completed, the above mixture is sent into a twin-screw extruder with a vacuum system and a temperature control system while the vacuum pressure of the twin-screw extruder is set to 50 KPa; in the heating section of the twin-screw extruder, the material is heated to 200°C within 8 min, and then kept at a constant temperature for 7 min; in the cooling section, the material is cooled to 90°C within 10 min, to obtain a solid coal combustion aid.

[0132] (4) The above solid coal combustion aid is mixed with coal samples according to a mass ratio of 0.3:99.7 to obtain coal combustion with the addition of the coal combustion aid.

[0133] Example 7

[0134] The preparation method of the present example is basically consistent with that of Example 1, and the only difference is that the proportion of the solid coal combustion aid is different. Specifically, the proportion of the solid coal combustion aid in the present example is: 50wt% of propylene acid heavy component decomposition reactor bottom liquid 7, 15wt% of calcium oxide powder, 20wt% of potassium nitrate oxidizing agent, and 15wt% of manganese dioxide catalyst.

[0135] Example 8

[0136] The preparation method of the present example is basically consistent with that of Example 1, and the only difference is that the proportion of the solid coal combustion aid is different. Specifically, the proportion of the solid coal combustion aid in the present example is: 75wt% of propylene acid heavy component decomposition reactor bottom liquid 7, 10wt% of calcium oxide powder, 10wt% of potassium permanganate oxidizing agent, and 5wt% of aluminum oxide catalyst.

[0137] Example 9

[0138] The preparation method of the present example is basically consistent with that of Example 2, and the only difference is that the proportion of the coal combustion aid is different. In the present example, no calcium oxide powder is added. Specifically, the proportion of the coal combustion aid in the present example is: 85wt% of butyl acrylate heavy component decomposition reactor bottom liquid 4, 10wt% of potassium nitrate oxidizing agent, and 5wt% of manganese dioxide catalyst. Other steps are basically consistent with those of Example 2.

[0139] Example 10

[0140] The preparation method of the present example is basically consistent with that of Example 3, and the only difference is that the composition of the depolymerization reactor bottom liquid in the present example is different. The depolymerization reactor bottom liquid used in the present example is depolymerization reactor bottom liquid 3 of a mixture of propylene acid heavy component and butyl acrylate heavy component. Other steps are basically consistent with those of Example 1.

[0141] Example 11

[0142] The preparation method in this embodiment is basically the same as that in Example 3, except that the composition of the depolymerization bottom liquid is different. The depolymerization bottom liquid used in this embodiment is a mixture of acrylic acid recombinant depolymerization bottom liquid 7 and butyl acrylate recombinant depolymerization bottom liquid 4 in a mass ratio of 1:3. The other steps are basically the same as in Example 1.

[0143] Comparative Example 1

[0144] The preparation method of this comparative example is basically the same as that of Example 3, except that the composition and ratio of the coal combustion additive are different. Specifically, the ratio of the coal combustion additive in this comparative example is: 100wt% of acrylic acid heavy component and butyl acrylate heavy decomposition polyhydric acid bottom liquid 1, without adding other components. Other steps are basically the same as those in Example 3.

[0145] Comparative Example 2

[0146] The preparation method of this comparative example is basically the same as that of Example 3, except that the composition ratio of the coal combustion additive is different. Specifically, the ratio of the coal combustion additive in this comparative example is: 29 wt% calcium oxide powder, 59 wt% potassium nitrate oxidant, and 12 wt% manganese dioxide catalyst. Other steps are basically the same as those in Example 3.

[0147] Comparative Example 3

[0148] This comparative example uses blank coal samples without added combustion additives.

[0149] The formulations of the coal combustion additives prepared in the above embodiments and comparative examples are shown in Tables 2 and 3.

[0150] Table 2

[0151]

[0152] Table 3

[0153]

[0154] Performance testing

[0155] The ignition point and burnout point of the coal and blank coal samples prepared in the above embodiments and comparative examples were measured using a thermogravimetric analyzer. The range was from room temperature to 950°C, and the heating rate was 10°C / min. The combustion characteristics of the samples were analyzed.

[0156] Calorific value test: The calorific value of the coal combustion additives prepared in each example and comparative example was tested according to the method specified in GB / T 384-1981 Method for Determination of Calorific Value of Petroleum Products.

[0157] The test data of the initial ignition point and burnout point of coal in each embodiment and comparative example are shown in Table 4.

[0158] Table 4

[0159]

[0160] In combination with Table 4, comparing Examples 1-9 with Comparative Example 3, it can be seen that whether the depolymerization kettle bottom liquid of the single acrylic acid heavy component or the depolymerization kettle bottom liquid of the butyl acrylate heavy component, or the mixture of the depolymerization kettle bottom liquid of the acrylic acid heavy component and the butyl acrylate heavy component is mixed with the oxidizing agent and the catalyst to prepare the solid coal combustion aid, the combustion characteristics of the coal sample after the solid coal combustion aid is added are greatly improved. Among them, the starting ignition point of the coal prepared in Example 3 is 479.81°C, and the burnout point is 713.89°C, which has a high combustion efficiency.

[0161] Compared with Example 9, the addition of calcium oxide in Example 2 can reduce the calorific value of the coal combustion aid itself by a small amount, but can improve the strength of the solid coal combustion aid, and the strong acidity can also be neutralized, reducing the corrosion and damage to the equipment.

[0162] The starting ignition point of the coal prepared by the coal combustion aid prepared in Comparative Example 1 is 483.01°C, and the burnout point is 722.46°C, which is higher than that of Example 3. It shows that the combustion efficiency of the coal prepared in Comparative Example 1 is not as good as that of Example 3.

[0163] The starting ignition point of the coal prepared by the coal combustion aid prepared in Comparative Example 2 is 481.34°C, and the burnout point is 719.59°C, which is higher than that of Example 3. It shows that the combustion efficiency of the coal prepared in Comparative Example 1 is not as good as that of Example 3.

[0164] In summary, the depolymerization kettle bottom liquid of the acrylic acid heavy component and the depolymerization kettle bottom liquid of the acrylic acid heavy component have a certain promoting effect on the combustion of coal, and can better improve the combustion of coal when prepared into a solid coal combustion aid with other oxidizing agents and catalysts in a suitable proportion. The addition of calcium oxide powder can greatly reduce the corrosiveness and stickiness of the material and improve the strength of the solid coal combustion aid.

[0165] The technical features of the above-described embodiments can be combined in any manner. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the description.

[0166] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but should not be understood as a limitation on the patent scope of the present application. It should be noted that, for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims, and the description can be used to explain the content of the claims.

Claims

1. A coal combustion aid characterized by, The components include depolymerization kettle bottom liquid, catalyst and oxidant; The depolymerization kettle bottom liquid includes depolymerization kettle bottom liquid of at least one of acrylic acid heavy component and butyl acrylate heavy component; The preparation method of the depolymerization kettle bottom liquid includes: under the action of an acid catalyst, at least one of acrylic acid heavy component and butyl acrylate heavy component is subjected to depolymerization reaction to obtain the depolymerization kettle bottom liquid; The pressure of the depolymerization reaction is -0.09 MPa to 0.05 MPa, the temperature is 100 DEG C to 350 DEG C, and the time is 5 h to 15 h; According to mass percentage, the depolymerization kettle bottom liquid includes 0% to 98% of acrylic acid polymer, 1% to 14% of maleic anhydride, 0% to 99% of butyl acrylate polymer and 0 to 5% of butoxy butyl propionate; the acrylic acid polymer and the butyl acrylate polymer are not zero at the same time; The acrylic acid heavy component is a kettle bottom liquid component of acrylic acid prepared by propylene oxidation; The butyl acrylate heavy component is a kettle bottom liquid component in a rectification process of crude butyl acrylate obtained by esterification reaction of acrylic acid and n-butanol under the action of an acid catalyst.

2. The coal combustion aid of claim 1, wherein The coal combustion aid satisfies one of the following conditions: (1) according to mass percentage, the depolymerization kettle bottom liquid includes 85% to 98% of acrylic acid polymer and 1% to 10% of maleic anhydride; (2) according to mass percentage, the depolymerization kettle bottom liquid includes 90% to 99% of butyl acrylate polymer, 0 to 5% of butoxy butyl propionate and 0 to 4% of maleic anhydride; (3) according to mass percentage, the depolymerization kettle bottom liquid includes 25% to 72% of acrylic acid polymer, 1% to 2% of maleic anhydride, 24% to 75% of butyl acrylate polymer and 0% to 5% of butoxy butyl propionate.

3. The coal combustion aid according to any one of claims 1 to 2, characterized in that, According to mass fraction, the coal combustion aid includes 50 parts to 85 parts of the depolymerization kettle bottom liquid, 1 part to 30 parts of oxidant and 1 part to 20 parts of catalyst.

4. The coal combustion aid of claim 3, wherein According to mass fraction, the coal combustion aid further includes 5 parts to 10 parts of alkaline inorganic filler.

5. The coal combustion aid of claim 4, wherein According to mass fraction, the coal combustion aid includes 75 parts to 85 parts of the depolymerization kettle bottom liquid, 1 part to 10 parts of oxidant, 1 part to 5 parts of catalyst and 5 parts to 10 parts of alkaline inorganic filler.

6. The coal combustion aid according to any one of claims 4 to 5, characterized in that, The coal combustion aid satisfies at least one of the following conditions: (1) the oxidant is a metal salt; (2) the catalyst is a metal oxide; (3) the alkaline inorganic filler is selected from at least one of calcium oxide, calcium hydroxide, sodium hydroxide and potassium hydroxide.

7. The coal combustion aid of claim 6, wherein The coal combustion aid satisfies at least one of the following conditions: (1) the oxidant is selected from at least one of potassium permanganate, sodium nitrate, potassium nitrate and potassium chlorate; (2) the catalyst is selected from at least one of aluminum oxide, manganese dioxide, magnesium oxide and diiron trioxide.

8. A method for the preparation of a coal combustion aid, characterized in that, The method includes the following steps: The depolymerization kettle bottom liquid, the catalyst and the oxidant are mixed; the depolymerization kettle bottom liquid includes depolymerization kettle bottom liquid of at least one of acrylic acid heavy component and butyl acrylate heavy component; The preparation method of the depolymerization kettle bottom liquid includes: under the action of an acid catalyst, at least one of acrylic acid heavy component and butyl acrylate heavy component is subjected to depolymerization reaction to obtain the depolymerization kettle bottom liquid; The pressure of the depolymerization reaction is -0.09MPa to 0.05MPa, the temperature is 100℃ to 350℃, and the time is 5h to 15h; The depolymerization reactor bottom liquid comprises 0% to 98% of acrylic acid polymer, 1% to 14% of maleic anhydride, 0% to 99% of butyl acrylate polymer, and 0 to 5% of butoxy butyric acid by mass percentage; the acrylic acid polymer and the butyl acrylate polymer are not both 0 at the same time; The heavy component of acrylic acid is a reactor bottom liquid component of acrylic acid prepared by propylene oxidation; The heavy component of butyl acrylate is a reactor bottom liquid component of crude butyl acrylate in a rectification process, which is obtained by esterification reaction of acrylic acid and n-butanol under the action of an acid catalyst.

9. The method of claim 8, wherein the coal combustion aid is prepared by the steps of: The acid catalyst used in the depolymerization reaction is at least one selected from the group consisting of methyl sulfonic acid, p-toluene sulfonic acid, and sulfuric acid.

10. The production method according to claim 9, wherein Further comprising the following steps: After mixing the depolymerization reactor bottom liquid, the catalyst, and the oxidant, the obtained mixture is kept at a vacuum air pressure of 20KPa to 50KPa and a temperature of 180℃ to 200℃ for 5min to 10min.

11. Use of the coal combustion aid according to any one of claims 1 to 7 in the preparation of coal.

12. A coal-fired fuel, characterized by, The coal comprises a coal base material and the coal combustion aid according to any one of claims 1 to 7.

13. The coal-fired power plant of claim 12, wherein, The mass percentage of the coal combustion aid in the coal is 0.2% to 0.5%.

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