Method and device for providing hot air for waste plastic cracking

Abstract

The invention relates to a method for providing hot air for waste plastic cracking, which comprises the following steps: respectively providing hot air generated by a hot blast stove to a plastic thermal cracking reactor and a fractionating tower, carrying out cracking reaction on waste plastic and the hot air in the plastic thermal cracking reactor, and feeding a product after the reaction into the fractionating tower, hot air in the fractionating tower further reacts with products of the thermal cracking reactor, different gases and liquids are formed after fractionation, the gases enter a hot blast stove for cyclic utilization, and the liquids are transported outwards by an oil tank truck. The hot blast stove is used as a device for providing hot air for waste plastic cracking, and the hot air at 700-800 DEG C provided by the hot blast stove can be used as hot air for a plastic thermal cracking reactor and also can be used for supplying heat to a treatment vessel fractionating tower.

Description

Technical Field

[0001] The invention relates to the technical field of waste plastic treatment, and in particular to a method and a device for providing hot air for cracking waste plastic. Background Art

[0002] The use of plastic products has greatly facilitated people's lives, but it has also brought about very serious environmental pollution problems, which have not only affected the ecological balance of nature, but also hindered economic development. Therefore, the pollution control of waste plastics should be synchronized with economic development, and the recycling of waste plastics is the general trend.

[0003] Among the existing urban solid waste, the proportion of plastics has reached 15%-20%, most of which are various types of disposable plastic packaging products. There are mainly the following ways to deal with waste plastics at home and abroad: chemical raw material recovery, physical landfill, composite modification, combustion energy recovery and mechanical physical recovery.

[0004] 1. Chemical raw material recycling method is to decompose waste plastics into small molecules or oligomers by isolating them from air, heating them, catalytic cracking, or bio-enzyme decomposition, and then use them as new chemical raw materials.

[0005] 2. The physical landfill method is to directly bury waste plastics in natural landfills below the surface. Because plastics are generally light and not easy to rot, this method will cause the landfill to become a soft foundation, which will be difficult to use in the future and can easily cause secondary pollution to the environment.

[0006] 3. The composite modification and utilization method is to use waste plastics through physical methods and asphalt or building materials for composite modification and then use them for road paving or as building materials, etc.

[0007] 4. The combustion energy recovery method is to convert the heat of waste plastics into electrical energy through combustion or use the heat energy for metal smelting. This method particularly requires the combustion exhaust gas to be harmlessly treated.

[0008] 5. Mechanical and physical recycling method is to reprocess the waste plastics after recycling through crushing, cleaning, screening and classification, and re-granulation.

[0009] Among the above treatment methods, the chemical raw material recovery method has the greatest development potential. This method can make the most of various types of raw materials: it is applicable to single plastic products or plastic mixtures with other organic substances. The prerequisite for the large-scale use of this technology is to have stable and continuous hot air. The ironmaking hot air furnace in the metallurgical system is a device that can provide stable hot air. The hot air generated by this device not only has many characteristics such as stability and high temperature (high heat content), but also can adjust the temperature according to needs.

[0010] The technology of catalytic cracking of waste plastics to produce gas and liquid fuel is an effective means to solve the problem of waste plastic recycling. It not only has great social benefits, but also has high economic benefits. It is of great significance to achieve sustainable social development. Summary of the invention

[0011] The technical problem to be solved by the present invention is to provide a device for providing hot air for waste plastic cracking, which can not only provide a heat source for the plastic thermal cracking reactor, but also provide heat for the next step fractionator.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] A method for providing hot air for waste plastic cracking, wherein hot air generated by a hot air furnace is provided to a plastic thermal cracking reactor and a fractionation tower respectively, the waste plastic undergoes cracking reaction with the hot air in the plastic thermal cracking reactor, the reaction products enter the fractionation tower, the hot air in the fractionation tower further reacts with the thermal cracking reactor products, different gases and liquids are formed after fractionation, the gases enter the hot air furnace for recycling, and the liquids are transported out by tank trucks.

[0014] The hot air temperature of the hot air furnace is 700°C-800°C.

[0015] The CO and H2 gases in the gas fractionated in the fractionation tower are recovered and supplied to the hot blast stove for combustion, and the other gases are mixed with the flue gas in the furnace of the hot blast stove and then output as hot air.

[0016] A device for providing hot air for waste plastic cracking comprises a hot air stove, a plastic thermal cracking reactor, and a fractionating tower, wherein the hot air duct of the hot air stove is connected to the plastic thermal cracking reactor and the fractionating tower respectively, the gas fuel duct in the gas outlet of the fractionating tower is connected to the gas fuel inlet of the hot air stove, and the waste gas duct in the gas outlet of the fractionating tower is connected to the waste gas inlet of the hot air stove. The liquid outlet of the fractionating tower feeds materials to a tank truck.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The hot blast furnace of the present invention is a device for providing hot blast for waste plastic cracking. The hot blast provided by the hot blast furnace at 700℃-800℃ can not only be used as hot blast for plastic thermal cracking reactor, but also can be used to heat the processing vessel fractionation tower. The hot blast furnace has high thermal efficiency, which can reach 80%, and long service life, which can exceed 15 years.

[0019] The present invention utilizes hot air to pyrolyze waste plastics and dry distills them to generate various usable gases and liquids. The obtained gas fuel can be used as fuel for the hot air furnace and can be recycled, creating conditions for the subsequent expansion and use of various environmental protection measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention.

[0021] Figure 2 Schematic diagram of a hot air stove.

[0022] In the figure: hot air furnace 1, hot air pipeline 2, plastic thermal cracking reactor 3, distillation tower 4, gas fuel pipeline 5, exhaust gas pipeline 6, liquid outlet 7, tank truck 8, gas fuel inlet 11, exhaust gas inlet 12. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means more than two.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0026] A method for providing hot air for waste plastic cracking, wherein hot air generated by a hot air furnace is provided to a plastic thermal cracking reactor and a fractionation tower respectively, the waste plastic undergoes cracking reaction with the hot air in the plastic thermal cracking reactor, the reaction products enter the fractionation tower, the hot air in the fractionation tower further reacts with the thermal cracking reactor products, different gases and liquids are formed after fractionation, the gases enter the hot air furnace for recycling, and the liquids are transported out by tank trucks.

[0027] The hot air temperature of the hot air furnace is 700°C-800°C.

[0028] The CO and H2 gases in the gas fractionated by the distillation tower are recycled and supplied to the hot blast stove for combustion, and the other gases return to the hot blast stove and are mixed with the flue gas in the furnace of the hot blast stove and then output as hot air.

[0029] like Figure 1-Figure 2 A device for providing hot air for cracking waste plastics comprises a hot air furnace 1, a plastic thermal cracking reactor 3, and a fractionating tower 4. The hot air duct 2 of the hot air furnace 1 is connected to the plastic thermal cracking reactor 3 and the fractionating tower 4 respectively. The gas fuel duct 5 in the gas outlet of the fractionating tower 4 is connected to the gas fuel inlet 11 of the hot air furnace 1. The waste gas duct 6 in the gas outlet of the fractionating tower 4 is connected to the waste gas inlet 12 of the hot air furnace 1. The liquid outlet 7 of the fractionating tower 4 feeds the material to a tank truck 8.

[0030] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. In addition, the various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

[0031] In order to make the purpose, technical scheme and technical effect of the present invention clearer, the technical scheme in the embodiment of the present invention is now clearly and completely described. However, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. In combination with the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example:

[0033] A device for providing hot air for waste plastic cracking comprises a hot air furnace 1, a plastic thermal cracking reactor 3, and a fractionating tower 4. The hot air duct 2 of the hot air furnace 1 is respectively connected to the plastic thermal cracking reactor 3 and the fractionating tower 4. The gas fuel duct 5 in the gas outlet of the fractionating tower 4 is connected to the gas fuel inlet 11 of the hot air furnace 1. The waste gas duct 6 in the gas outlet of the fractionating tower 4 is connected to the waste gas inlet 12 of the hot air furnace 1. The liquid outlet of the fractionating tower 4 feeds material to a tanker 8.

[0034] The working method of the device for providing hot air for waste plastic cracking is that the hot air provided by the hot blast furnace 1 with a maximum temperature of 750°C-800°C is provided to the plastic thermal cracking reactor 3 and the fractionation tower 4 respectively. The waste plastic enters from the upper part of the thermal cracking reactor 3, and the hot air enters from the lower part. Through the reverse flow of high-temperature gas and materials, the waste plastic undergoes a cracking reaction in the plastic thermal cracking reactor 3. The reaction product enters the fractionation tower 4, and under the action of the hot air, it is graded to produce a variety of gases and liquids. The gas fuel CO and H2 in the gas are recycled and supplied to the hot blast furnace 1 for use as fuel. Other gases return to the hot blast furnace 1, as the temperature regulator of the hot blast furnace 1, enter the upper part of the hot blast furnace 1 and mix with the flue gas generated by the hot blast furnace 1, adjust the flue gas temperature, and then output as hot air. The liquids produced by the fractionation tower 4, including gasoline, diesel, heavy oil and alkane substances, are transported away by tank trucks.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and basic spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for providing hot air for waste plastic cracking, characterized in that: The hot air generated by the hot air furnace is provided to the plastic thermal cracking reactor and the distillation tower respectively. The waste plastics undergo cracking reaction with the hot air in the plastic thermal cracking reactor, and the reaction products enter the distillation tower. The hot air in the distillation tower further reacts with the products of the thermal cracking reactor to form different gases and liquids after fractionation. The gas enters the hot air furnace for recycling, and the liquid is transported out by tanker trucks.

2. A method for providing hot air for waste plastic cracking according to claim 1, characterized in that: The hot air temperature of the hot air furnace is 700°C-800°C.

3. A method for providing hot air for waste plastic cracking according to claim 1, characterized in that: The CO and H2 gases in the gas fractionated by the distillation tower are recycled and supplied to the hot blast stove for combustion, and the other gases return to the hot blast stove and are mixed with the flue gas in the furnace of the hot blast stove and then output as hot air.

4. The device for providing hot air for waste plastic cracking used in the method of claim 1 is characterized in that: It includes a hot blast furnace, a plastic thermal cracking reactor, and a fractionating tower. The hot blast duct of the hot blast furnace is connected to the plastic thermal cracking reactor and the fractionating tower respectively. The gas fuel pipeline in the gas outlet of the fractionating tower is connected to the gas fuel inlet of the hot blast furnace. The waste gas pipeline in the gas outlet of the fractionating tower is connected to the waste gas inlet of the hot blast furnace. The liquid outlet of the fractionating tower is fed to a tank truck.

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