KR102353693B1 - Alternative fuel gasifier including plasma combustion system - Google Patents

Abstract

The present invention uses a plasma combustion system to gasify and burn waste plastic through thermal decomposition, and it is possible to reduce fuel consumption by supplying an additional heat source to a preheating tower attached to a cement kiln, and harmful gases and It relates to an alternative fuel gasification combustion device including a plasma combustion system capable of continuous and economical operation by reducing tar generation. The present invention is (a) a combustion reactor; (b) 4 to 20 plasma combustion means for supplying plasma to the combustion reactor; (c) it provides an alternative fuel gasifier including a plasma combustion system including a fuel supply means connected to the upper half of the combustion reactor for supplying the waste plastic in the direction of the combustion reactor.

Description

Alternative fuel gasifier including plasma combustion system

The present invention relates to an alternative fuel gasification combustion apparatus including a plasma combustion system, and more particularly, to gasification and combustion through pyrolysis of waste plastics discarded using a plasma combustion system. It relates to an alternative fuel gasification combustion device including a plasma combustion system capable of reducing fuel consumption by supplying a heat source, and capable of continuous and economical operation by reducing the generation of harmful gases and tars caused by plastic combustion.

Plastic is a type of polymer compound produced by combining raw materials extracted from petroleum, and refers to a macromolecule in which hydrogen and other functional groups are bonded mainly to a carbon skeleton. In the early days, it was mainly developed to replace rubber or rosin, which are natural resins, and is called synthetic resin, but now, millions of plastics with various properties have been developed and used in an overwhelming proportion compared to the amount of natural resin used. The first plastic developed was a phenolic resin (bakelite) developed to replace ivory used in billiard balls, and was manufactured in 1907 by polymerizing phenol and formaldehyde. In the early days, plastics were considered only as substitutes for ivory or children's toys, but recently, plastics are recognized as an important material indispensable in all industries. In particular, engineering plastics, which have solved the strength problem of existing plastics, are in the spotlight as an alternative to steel materials. Plastics are used for most of the products that are prone to breakage because they have superior stability compared to glass or iron in case of breakage.

Plastics are largely divided into thermoplastic resins and thermosetting resins depending on whether they can be softened by heat. Thermoplastic resin is a plastic having fluidity due to the loosening of the bonds between polymer chains when heat is applied. Thermosetting resins are plastics that strengthen the bonds between polymer chains when heat is applied. They are liquids or solids with fluidity before hardening and are easy to process. have However, these thermosetting plastics have higher strength and better heat resistance than thermoplastic plastics, so they are mainly used in industrial fields such as engineering plastics that require high strength.

As these plastics are easy to process, they can be manufactured in a desired shape and color, and have a long lifespan because they hardly decompose naturally, and have the advantage of being able to easily manufacture desired properties. The disposal of plastics is a problem. In general, plastics after use are disposed of in landfills, but they have limitations because they take a lot of time to decompose during landfilling. Therefore, a method of recycling plastic raw materials has been proposed as a method to solve this problem, but only thermoplastic resins can be recycled, and there is a difficulty in separating millions of plastics by type, so the recycling rate cannot be significantly improved. to be.

In order to solve the disadvantages of such plastics, biodegradable plastics are being developed. However, in the case of such biodegradable plastics, it is difficult to use for a long time and is used only in limited fields due to poor physical properties compared to general plastics.

However, in the case of plastics, most of them are petroleum-derived materials and are polymer materials with a carbon-based basic skeleton, so methods for using them as fuels are also being developed. In the case of plastic, it is expected to be able to replace some of the fossil fuel when it is used as a fuel because it can generate a similar amount of heat to that of a fossil fuel of the same weight. However, plastic is a material with a large molecular weight, and incomplete combustion occurs in many cases to generate toxic gas. It has been proposed to be done.

Meanwhile, in the case of cement kilns, kiln-type reactors are mainly used. This kiln is a kind of kiln used for cement firing, and a rotary type kiln is mainly used for continuous operation. In the case of a rotary kiln, it is composed of a pipe-shaped reactor having a certain angle with the ground, and raw materials are supplied from one side of the reactor, and as the pipe-shaped reactor rotates, the reaction occurs while moving to the other side of the reactor. At this time, the raw material rises to a certain height by the rotation of the reactor and is mixed while repeating falling downward by gravity, and bituminous coal is used as a heating means at the end of the reactor to maintain the reactor at a constant temperature. Such a rotary kiln has a characteristic that mixing is repeated by rotation, and the amount of production can be adjusted according to the diameter and rotational speed of the reactor.

At this time, in order to maintain the kiln at a constant temperature, a large amount of heat is required, and accordingly, a large amount of fossil fuel is used, so an effort to reduce it is required. In addition, in recent years, as the Convention for the Prevention of Global Warming (Kyoto Protocol) was signed in order to reduce the amount of carbon dioxide generated in terms of environmental protection, carbon dioxide reduction is emerging as an overall social issue. There is a need for a variety of methods for this.

(0001) Republic of Korea Patent Publication No. 10-2010-0061472 (0002) Republic of Korea Patent Publication No. 10-2001-0015905

In order to solve the above problem, the present invention pyrolyzes, gasifies, and burns waste plastics discarded using a plasma combustion system. It is possible to reduce the amount of fuel used by supplying an additional heat source to the preheating tower attached to the cement kiln, An object of the present invention is to provide an alternative fuel gasifier including a plasma combustion system capable of continuous and economical operation by reducing harmful gas and tar generation due to plastic combustion, and a cement kiln heating method using the same.

In order to solve the above problem, the present invention is (a) a combustion reactor; (b) four or more plasma combustion means for supplying plasma to the combustion reactor; (c) it provides an alternative fuel gasifier including a plasma combustion system including a fuel supply means connected to the upper half of the combustion reactor for supplying the waste plastic in the direction of the combustion reactor.

In the combustion reactor, the fuel supply means may be connected to one side upwardly, and a gas outlet may be formed downwardly on the other side.

It may include a plasma combustion system characterized in that the auxiliary combustion means for additionally supplying air or oxygen is installed at the lower inner side of the combustion reactor.

In the auxiliary combustion means, 2 to 100 perforated portions are arranged at regular intervals, and air or oxygen may be supplied through the perforated portions.

The combustion reactor may have an internal temperature of 500 to 2000°C, and the temperature of the discharged gas may be 800 to 2000°C.

The plasma combustion means may be arranged at regular intervals on both sides of the combustion reactor along a direction horizontal to the bottom of the combustion reactor.

Each of the plasma combustion means has an output of 10 to 50 kW, and the plasma discharge temperature may be 5000 to 7000K.

The fuel supply means may include a fuel delivery means including one or more screws or pressure feeding devices rotating in opposite directions therein.

A fuel dispersing means for uniformly supplying the waste plastic to the inside of the combustion reactor may be installed between the fuel supply means and the combustion reactor.

The fuel distribution means may include a mesh network, a structure at regular intervals arranged in multiple layers, a rotating circular plate, or a rotating blade.

The alternative fuel gasifier including the plasma combustion system according to the present invention supplies and recycles high-temperature waste gas air generated in the cement burning process to the preheating tower attached to the cement kiln, unlike the existing plastic incinerator, so the emission of hazardous substances As it has the effect of reducing the fuel cost of the preheating tower attached to the cement kiln, it can be applied not only to the cement kiln, but also to other industries that use waste plastics such as power plants and paper companies.

1 schematically shows the concept of an alternative fuel gasifier and cement kiln including a plasma combustion system according to an embodiment of the present invention.
2 is a view showing the combination of the plasma combustion system and the cement kiln according to an embodiment of the present invention.
3 is a photograph showing the plasma generation of the plasma combustion means according to an embodiment of the present invention.
4 is a view schematically showing the combination of the combustion reactor and the plasma combustion means according to an embodiment of the present invention.
5 is a schematic view of an operating method of a combustion reactor according to an embodiment of the present invention.
6 is a view showing a raw material supply means according to an embodiment of the present invention.
7 is a view showing a means for supplying high-temperature waste gas air generated in the firing process according to an embodiment of the present invention.
8 briefly shows the shape of the combustion reactor and the position of the thermocouple thermometer according to an embodiment of the present invention.
9 is a result of measuring the temperature of each part of the combustion reactor using the gas generated from the kiln according to an embodiment of the present invention.
10 is a photograph of the collected combustion reactor residue according to an embodiment of the present invention.
11 is an FE-SEM photograph of the collected combustion reactor residue according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present invention, the terms include or have is intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features, number, step , it should be understood that it does not preclude in advance the possibility of the presence or addition of an operation, component, part, or combination thereof.

The present invention is (a) a combustion reactor; (b) four or more plasma combustion means for supplying plasma to the combustion reactor; (c) it relates to an alternative fuel gasifier including a plasma combustion system including a fuel supply means connected to the upper half of the combustion reactor for supplying the waste plastic in the direction of the combustion reactor.

The combustion reactor is a device for gasifying and supplying the waste plastic supplied from the fuel supply means, and is manufactured in a square or circular pipe shape, a fuel supply means is installed on one side of the axial direction, and a gas exhaust means is installed on the other side. can The combustion reactor may also be manufactured in a vertical cylindrical or quadrangular column shape. In this case, a fuel supply means may be connected to one side of the upper part, and a gas discharge means may be installed to the other side of the lower part. That is, it is preferable that the fuel supply means is installed at the upper end of one side of the combustion reactor, and the gas discharge means is installed at the lower end of the other side. Accordingly, the waste plastic supplied by the fuel supply means passes through the combustion reactor and is discharged in the direction of the gas outlet on the other side, and the generated gas may also be discharged in the direction of the gas outlet.

In addition, the combustion reactor may be manufactured as a combustor having a single combustion unit, and may be composed of two stages, an upper end 100 and a lower end 110 in order to increase combustion efficiency (see FIG. 4 ). At this time, the plasma combustion means 200 is installed at the upper end, and the air supply nozzle for combustion may be located at the lower end to perform combustion more smoothly. In this case, the air supplied from the combustion air supply nozzle additionally oxidizes the gas primary combusted at the upper end of the combustion reactor and supplies it to the gas discharge means, and at the same time, a portion is supplied to the upper end of the combustion reactor to perform primary combustion. can be done When the combustion reactor is operated by dividing the combustion reactor into an upper part and a lower part, the amount of ash and tar generated can be significantly reduced because the waste plastic is gasified and completely burned (refer to FIG. 5). In addition, when additional combustion is required, it is also possible to configure a combustion chamber of 3 to 10 stages by adding a stage to the lower end of the lower end.

An auxiliary combustion means capable of supplying air or oxygen may be installed at an inner lower portion of the combustion reactor. In the case of the combustion reactor, as air and combustion products are supplied from the upper part, in the case of an alternative fuel (waste plastic) stored in the lower part, oxygen supply is not smooth, and incomplete combustion may occur. Therefore, it is preferable to provide an auxiliary combustion means for supplying additional oxygen to the inside of the combustion reactor to facilitate the supply of oxygen. At this time, the auxiliary combustion means may simply supply external air, it is also possible to supply pure oxygen. In addition, in the auxiliary combustion means, 2 to 100 perforated portions are arranged at regular intervals, and air or oxygen may be supplied through the perforated portions.

The combustion reactor may include four or more plasma combustion means for supplying plasma, preferably 4 to 20 combustion means (see FIG. 4). In the case of the conventional combustor for waste plastics, combustion was performed using fossil fuels. However, in the case of fossil fuels, not only can they generate their own toxic gases, but also the amount of carbon dioxide generated increases, so their use is limited. In addition, in the case of the combustor using the fossil fuel, the flame temperature is low, so that the temperature inside the combustion reactor cannot be dramatically increased. Accordingly, in the present invention, the same combustion reaction can be performed while increasing the temperature inside the combustion reactor by using the plasma combustion means, minimizing the amount of fossil fuel used, and also minimizing the amount of heat used due to the high temperature.

The plasma combustion means may be arranged at regular intervals on both sides of the combustion reactor along a direction horizontal to the bottom of the combustion reactor (see FIG. 4 ). In the case of the plasma combustion means, it is preferable to uniformly supply plasma to the inside of the combustion reactor. In particular, when the waste plastics are accumulated on the bottom of the combustion reactor as the waste plastics fall, they are preferably arranged at regular intervals on both sides of the combustion reactor along the horizontal direction with the bottom of the combustion reactor in order to burn them uniformly. However, when the combustion reactor is composed of two stages of the upper end and the lower end, 2 to 16 of the plasma combustion means are arranged at the upper end, and 2 to 4 are arranged at the lower end, and waste plastic falling to the upper end is disposed. It is preferable to burn intensively (see FIGS. 4 and 5).

The combustion reactor may have an internal temperature of 500 to 2000°C, and the temperature of the discharged gas may be 800 to 2000°C. In the case of conventional plastic incinerators using fossil fuels, the internal temperature was about 900 to 1400 °C, which did not reach a temperature sufficient to completely burn and gasify the plastic. However, in the case of the present invention, combustion can be performed at a high temperature using a plasma combustion means, and the internal temperature can be maintained at 500 to 2000° C. by preventing the temperature drop as much as possible. The internal temperature is very different depending on the type of plastic supplied, but in general, the higher the carbon ratio and the lower the average molecular weight of the polymer, the higher the temperature can be. In addition, when the temperature inside the combustion reactor is lowered to less than 500 ℃, tar may be deposited inside the combustion reactor due to incomplete reaction of the plastic. Therefore, it is preferable to set the temperature inside the combustion reactor to 500°C or higher. In addition, the combustion reactor has an inlet temperature as low as possible, and since the exhaust gas is exhausted from the combustion inside the combustion reactor, a gas having a temperature higher than 500° C., which is the lowest temperature of the combustion reactor, can be discharged. Therefore, the temperature of the discharged gas may be 800 ~ 2000 ℃. If the temperature of the discharged gas is less than 800 °C, tar may be deposited on the gas outlet, and if it exceeds 2000 °C, the gas outlet is overheated, so additional heat dissipation equipment must be installed, thereby reducing economic efficiency.

The fuel supply means may include a fuel delivery means including one or more screws or pressure feeding devices rotating in opposite directions therein (FIG. 6). In the case of the existing plastic incinerator, a method of constantly supplying waste plastics using a hopper was used. However, the method using such a hopper inevitably causes a temperature drop inside the combustion reactor due to the simultaneous supply of waste plastics, so the inner surface of the combustion reactor This resulted in the deposition of tar. Accordingly, in the present invention, a fuel transport means including one or more screws or pressure feeding devices rotating in opposite directions is installed inside the fuel supply means to continuously supply waste plastic at a constant speed to lower the temperature inside the combustion reactor. It is preferable to prevent In addition, even if the waste plastic is supplied using the fuel transport means as described above, when the waste plastic is intensively supplied only to a certain space inside the combustion reactor, uniform combustion is impossible and a local temperature drop may occur, so the fuel supply means It is preferable that a fuel dispersing means for uniformly supplying the waste plastic to the inside of the combustion reactor is installed between the combustion reactor and the combustion reactor. The fuel dispersing means uniformly supplies the waste plastic supplied by the fuel supply means to the inside of the combustion reactor, thereby preventing a temperature drop to enable a uniform combustion reaction and at the same time prevent the formation of tar as much as possible. The fuel dispersing means can be used without limitation as long as it can uniformly disperse the waste plastics inside the combustion reactor, but dispersing the waste plastics using a mesh network, a structure at regular intervals arranged in multiple layers, or rotating blades desirable.

In addition, it is possible to increase the combustion efficiency of the combustion reactor by supplying high-temperature waste gas air generated in the cement firing process to the combustion reactor. In detail, the calcination of the cement by heat is continuously performed inside the kiln, and the air inside is also discharged according to the discharge of the calcined cement. In the process of cooling clinker, the semi-finished cement product produced through this process, high-temperature waste gas air is generated. When this is supplied to the combustion reactor and used as combustion air, combustion efficiency can be greatly increased. In this case, part or all of the heated air generated inside the kiln may be supplied to the combustion reactor according to the oxygen consumption of the combustion reactor, and the external supplied to the combustion reactor to maintain the optimum temperature inside the combustion reactor It may be supplied in the form of mixing with air. In this case, the heated air generated inside the kiln may have a temperature of 500 to 1000°C.

The cement kiln may detoxify harmful gas contained in the gas supplied from the alternative fuel gasifier. The preheating tower attached to the cement kiln burns the gas supplied from the alternative fuel gasifier once more to supply heat, so it can oxidize and remove various harmful gases contained in the gas supplied from the alternative fuel gasifier. In particular, in the case of dioxin, HCN, CO or NOx, which are frequently generated during incineration of waste plastics, most of the harmful gases generated from the existing waste plastic incinerators can be removed because additional incineration and prevention facilities of the kiln are used. At this time, the harmful gas may be removed by being converted into the form of N2, CO2 or H2O.

Hereinafter, preferred embodiments of the present invention will be described so that those of ordinary skill in the art can easily implement them with reference to the accompanying drawings. In addition, in the description of the present invention, when it is determined that a detailed description of a related known function or a known configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, some features presented in the drawings are enlarged, reduced, or simplified for ease of description, and the drawings and components thereof are not necessarily drawn to scale. However, those skilled in the art will readily appreciate these details.

Example 1

An experiment was conducted to measure the effect of an alternative fuel gasification combustion apparatus including a plasma combustion system according to the present invention. After manufacturing an alternative fuel gasification combustion apparatus in the same manner as shown in FIG. was installed to measure the temperature. T8 is the temperature of the air supplied from the cement kiln to the gasification combustion unit for alternative fuels.

As shown in FIG. 9, waste plastics (fuel) were introduced at appropriate intervals. It was found that the temperature (TC6) of the gas generated from the alternative fuel gasification combustion device was maintained at about 800~1400℃. In addition, it was found that the temperature (TC8) of the air supplied from the cement kiln is maintained at 400 ~ 600 °C and is supplied to the gasification combustion device for alternative fuels, contributing greatly to the temperature increase of the exhaust gas.

Example 2

The residue after treatment in Example 1 was analyzed.

As shown in FIG. 10, after collecting the residues, five analytical samples were collected and analyzed, and the results are shown in Table 1.

sample 1 sample 2 sample 3 sample 4 sample 5 average C 0 0 0 3.21 4.31 1.504 O 29.95 37.14 39.41 38.91 40.62 37.206 Na 6.17 4.42 6.98 5.83 4.84 5.648 Mg 0 0.83 0.89 0.87 0.91 0.7 Al 1.77 2 1.34 1.54 1.93 1.716 Si 20.2 25.28 27.48 28.34 28 25.86 Cl 10.02 4.9 0.98 3.06 2.18 4.228 K 2.67 1.25 0 0 0 0.784 Ca 27.56 24.18 14.56 18.24 17.21 20.35 Fe 1.66 0 3.35 0 0 1.002 Cu 0 0 5.01 0 0 1.002 Sum 100 100 100 100 100 100

As shown in Table 1, it was confirmed that most of the carbon, which is a major component of plastic and capable of combustion, was gasified and removed. That is, in the case of the present invention, it was confirmed that carbon, which occupies 80 to 95% by weight of the plastic, can be removed by combustion and gasification, and thus 80 to 95% by weight of the supplied waste plastic can be removed by combustion or gasification.

In addition, as shown in FIG. 11 , the residue was confirmed to have porosity, so it was predicted that there would be a possibility of using it as a building material, a covering material, and the like.

As a specific part of the present invention has been described in detail above, for those of ordinary skill in the art, it is clear that this specific description is only a preferred embodiment, and the scope of the present invention is not limited thereby. will be. Accordingly, it is intended that the substantial scope of the present invention be defined by the appended claims and their equivalents.

100: upper end of combustion reactor
110: lower part of the soft water reactor
200: plasma combustion means

Claims (10)

(a) a combustion reactor;
(b) four or more plasma combustion means for supplying plasma to the combustion reactor;
(c) a fuel supply means connected to the upper half of the combustion reactor for supplying the waste plastic in the direction of the combustion reactor;
The combustion reactor consists of two stages, an upper end and a lower end, the plasma combustion means is installed at the upper end, and a combustion air supply nozzle is located at the lower end to perform combustion more smoothly, the combustion air The air supplied from the supply nozzle additionally oxidizes the gas primarily combusted at the upper end and supplies it to the gas outlet, and at the same time, a portion is supplied to the upper end of the combustion reactor to perform primary combustion,
An auxiliary combustion means for additionally supplying air or oxygen is disposed on the lower inner side of the combustion reactor,
The plasma combustion means are arranged at regular intervals on both sides of the combustion reactor along a horizontal direction with the bottom of the combustion reactor,
The plasma combustion means is arranged in 2 to 16 pieces on the upper end, and 2 to 4 pieces are arranged on the lower end to burn the waste plastic falling on the upper end centrally,
Mixing and supplying the high-temperature gas discharged from the plasma combustion means with the fuel for heating the preheating tower attached to the cement kiln,
Alternative fuel gasification combustion apparatus including a plasma combustion system, characterized in that the pyrolysis by injecting greenhouse gas into the cement kiln.
According to claim 1,
The combustion reactor is an alternative fuel gasification combustion device including a plasma combustion system, characterized in that the fuel supply means is connected to the upper side on one side, and the gas outlet is formed on the other side downward.
According to claim 1,
Alternative fuel gasification combustion apparatus including a plasma combustion system, characterized in that the auxiliary combustion means for additionally supplying air or oxygen is installed in the lower inner side of the combustion reactor.
4. The method of claim 3,
The auxiliary combustion means is an alternative fuel gasification combustion device including a plasma combustion system, characterized in that 2 to 100 perforated parts are arranged at regular intervals, and air or oxygen is supplied through the perforated parts.
According to claim 1,
The combustion reactor has an internal temperature of 500 ~ 2000 ℃, an alternative fuel gasification combustion apparatus including a plasma combustion system, characterized in that the temperature of the discharged gas is 800 ~ 2000 ℃.
According to claim 1,
The plasma combustion means is an alternative fuel gasification combustion apparatus including a plasma combustion system, characterized in that arranged at regular intervals on both sides of the combustion reactor along a horizontal direction with the bottom of the combustion reactor.
According to claim 1,
The plasma combustion means has an output of 10 to 50 kW, respectively, and an alternative fuel gasification combustion apparatus including a plasma combustion system, characterized in that the discharge temperature of the plasma is 5000 to 7000K.
delete According to claim 1,
Alternative fuel gasification combustion apparatus including a plasma combustion system, characterized in that a fuel dispersing means for uniformly supplying the waste plastic to the inside of the combustion reactor is installed between the fuel supply means and the combustion reactor.
10. The method of claim 9,
The fuel dispersing means is an alternative fuel gasification combustion apparatus including a plasma combustion system, characterized in that it includes a mesh network, a structure at regular intervals arranged in multiple layers, a rotating circular plate or a rotating blade.

Images