Instantaneous high temperature rise and directional regulation pyrolysis device and method

Abstract

The invention discloses a pyrolysis device and method with instantaneous high temperature rise and directional regulation and control, and the method comprises the following steps: putting a pyrolysis substance into a pyrolysis reaction vessel, introducing inert gas into a superheated steam inlet, and emptying air in the pyrolysis device; superheated steam is introduced into the superheated steam inlet, and a pressure regulating valve is regulated to enable the pressure in the tubular furnace to reach the required pressure; and collecting and treating the pyrolysis product at the pyrolysis product outlet. According to the method, the boiling point of the added water vapor is regulated and controlled by controlling the pressure of a reaction section according to a Clausius-Claelong equation, sufficient heat is provided for pyrolysis substances at a high-gasification latent heat speed of the water vapor, short-time efficient pyrolysis is realized, and production of by-products in the process is reduced compared with slow heating.

Description

Technical Field

[0001] The present invention relates to the fields of hydrogen energy production and utilization, waste treatment and resource recovery, and environmental protection, and in particular to a pyrolysis device and method with instantaneous high temperature rise and directional regulation. Background Art

[0002] Hydrogen energy has the characteristics of abundant sources, high energy density, clean and low carbon, and wide application. In the future global energy structure, the proportion of hydrogen energy will continue to increase, and hydrogen production is the basis of hydrogen energy application. 2 (Green hydrogen) has no carbon emissions, so it is more promising to shift the source of hydrogen energy from gray hydrogen to green hydrogen.

[0003] Waste plastics have a huge output and high hydrogen content, and have the potential for industrial hydrogen production. Waste plastics are complex in type, stable in structure and highly polymerized. The traditional high-temperature thermochemical waste plastic hydrogen production process has a high reaction temperature, a complex product composition, and very demanding requirements on the catalytic system and reaction equipment. At present, there are many problems with existing heating technologies that are not suitable for industrial hydrogen production: (1) In terms of heating and temperature rise: The problem with traditional heating methods is that it is extremely difficult to accurately control the process temperature, the equipment cost is very high, the power consumption is extremely large, the heating speed is slow, the energy efficiency is not high, and the operation process also has safety risks. (2) In terms of the target product generated: the reaction of ordinary pyrolysis experiments often produces some by-products due to slow heating, which wastes raw materials and may also inhibit the rate of the main reaction, thereby affecting the yield of the target product. (3) In terms of environmental pollution: ordinary pyrolysis experiments using traditional heating methods will produce many combustion reactions and pollutants such as chlorides (sulfides) generated by pyrolysis reactions.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a pyrolysis device and method with instantaneous high temperature rise and directional regulation, so as to solve the problem that some by-products are produced in the ordinary pyrolysis process due to slow heating.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0007] In a first aspect of the present invention, a pyrolysis device with instantaneous high temperature rise and directional control is provided, the pyrolysis device comprising a tubular furnace, a catalyst stick and a pyrolysis reaction vessel, a pressure regulating valve is arranged inside the tubular furnace, both ends of the tubular furnace are sealed by seals, and superheated steam inlet and pyrolysis product outlet are respectively provided on the seals at both ends of the tubular furnace; the catalyst stick is located inside the tubular furnace, one end of the catalyst stick is connected to the pyrolysis reaction vessel, and the other end is connected to the seal close to the superheated steam inlet, the catalyst stick comprises a molecular sieve and a catalyst loaded on the molecular sieve;

[0008] The pyrolysis device further comprises a pyrolysis product collecting device, which is connected to the tubular furnace via the pyrolysis product outlet and is used for collecting and processing the pyrolysis products.

[0009] Preferably, the pyrolysis product collecting device comprises a condenser, a liquid product collecting bottle, a gas washing bottle and a gas collecting bag which are connected in sequence, and the condenser is connected to the tubular furnace through the pyrolysis product outlet.

[0010] Preferably, the catalytic rod is provided with a temperature measuring thermocouple and an air pressure sensor, and the pyrolysis reaction vessel is provided with a temperature measuring thermocouple and an air pressure sensor.

[0011] Preferably, a plurality of the temperature measuring thermocouples are provided, and the temperature measuring thermocouples are evenly arranged on the surface of the catalyst stick and the upper and lower surfaces of the pyrolysis reaction vessel.

[0012] A second aspect of the present invention provides a pyrolysis method based on the above pyrolysis device, the method comprising the following steps:

[0013] Put the pyrolysis material into the pyrolysis reaction vessel, introduce inert gas into the superheated steam inlet, and exhaust the air in the pyrolysis device;

[0014] Introducing superheated steam into the superheated steam inlet, and adjusting the pressure regulating valve so that the pressure in the tube furnace reaches the required pressure;

[0015] The pyrolysis products are collected and processed at the pyrolysis product outlet.

[0016] Preferably, the introduction rate of the superheated water steam is 0.005-0.1 kg / s.

[0017] Preferably, the required pressure is 1.554-22.1 MPa.

[0018] Preferably, the pyrolysis material is one or more of polyvinyl chloride plastic, polyvinyl chloride plastic, polyethylene plastic, polypropylene plastic, polystyrene plastic, biomass waste, waste rubber, and carbon black.

[0019] Beneficial effects:

[0020] The present invention discloses a pyrolysis device and method with instantaneous high temperature rise and directional control. Compared with the problems of low heating efficiency, uneven product distribution, and many polluted products in traditional pyrolysis devices such as electric furnaces, the pyrolysis device provided by the present invention has a simple structure and is only composed of a tubular furnace, a catalytic stick, a pyrolysis reaction dish, and a pyrolysis product collection device. In addition, no heating is required during the pyrolysis process. It is only necessary to introduce superheated water vapor into the pyrolysis device, and the latent heat released by the superheated water vapor during the phase change process is used to rapidly heat the pyrolysis material to reach the target temperature, thereby reducing the byproducts of the pyrolysis heating process. The superheated water vapor can adjust the pyrolysis gaseous products by accurately controlling the reaction environment, increase the target products, and the high-temperature water vapor can decompose and utilize metal sulfides and chlorination, thereby reducing pyrolysis pollution.

[0021] Specifically, the present invention uses superheated water vapor as the heat transfer medium, controls the boiling point of the superheated water vapor by controlling the ambient pressure, and thus uses the high latent heat of vaporization of the superheated water vapor to rapidly perform pyrolysis at the required temperature for pyrolysis, thereby reducing the generation of process byproducts in a similar slow heating process. The method provided by the present invention can be widely used in the pyrolysis treatment process of organic matter such as coal, plastics, and waste, and is particularly suitable for improving pyrolysis efficiency and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of a pyrolysis device according to a preferred embodiment of the present invention.

[0023] Figure 2 An exploded view of a pyrolysis device according to a preferred embodiment of the present invention and a description of each part.

[0024] Figure 3 This is a partial detail diagram of a pyrolysis device according to a preferred embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the condenser structure in the pyrolysis device of a preferred embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the structure of a liquid product collecting bottle in a pyrolysis device in a preferred embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of the structure of the gas washing bottle in the pyrolysis device of a preferred embodiment of the present invention.

[0028] Figure 7 This is a schematic diagram of the structure of a gas collection bag in a pyrolysis device according to a preferred embodiment of the present invention.

[0029] Among them, 1 is a tubular furnace, 2. a catalytic stick, 3. a pyrolysis reaction vessel, 4. a sealing member, 5. an inlet for superheated steam, 6. an outlet for pyrolysis products, 7. a pyrolysis product collecting device, 71. a condenser, 72. a liquid product collecting bottle, 73. a gas washing bottle, and 74. a gas collecting bag. DETAILED DESCRIPTION

[0030] The present invention provides a pyrolysis device and method with instantaneous high temperature rise and directional control. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] The embodiment of the present invention provides a pyrolysis device with instantaneous high temperature rise and directional control, Figure 1-3 The pyrolysis device comprises a tubular furnace 1, a catalytic stick 2 and a pyrolysis reaction vessel 3. A pressure regulating valve is arranged inside the tubular furnace 1. Both ends of the tubular furnace 1 are sealed by a seal 4. The seals 4 at both ends of the tubular furnace 1 are respectively provided with a superheated steam inlet 5 and a pyrolysis product outlet 6; the catalytic stick 2 is located inside the tubular furnace 1, one end of the catalytic stick 2 is connected to the pyrolysis reaction vessel 3, and the other end is connected to the seal 4 near the superheated steam inlet 5. The catalytic stick 2 comprises a molecular sieve and a catalyst loaded on the molecular sieve;

[0032] The pyrolysis device further comprises a pyrolysis product collecting device 7 , which is connected to the tubular furnace 1 via the pyrolysis product outlet 6 and is used for collecting and processing the pyrolysis products.

[0033] In some embodiments, the seal 4 can be in the form of, but not limited to, traditional rubber plugs, high-pressure sealing flanges, etc., according to the reaction requirements; the tubular furnace is a high-temperature resistant quartz glass tubular furnace; the material of the catalyst stick can be adjusted according to the reaction type and the target product.

[0034] In some embodiments, the pyrolysis product collecting device 7 includes condensing pipes 71 connected in sequence (see Figure 4 ), liquid product collection bottle 72 (see Figure 5 ), washing bottle 73 (see Figure 6 ) and gas collection bag 74 (see Figure 7 ), the condenser 71 is connected to the tube furnace 1 through the pyrolysis product outlet 6.

[0035] In some embodiments, the catalyst stick 2 is welded to the pyrolysis reaction vessel 3 as a whole and fixed as a whole to the center of the tube furnace 1. A spherical condenser 71 is connected after the pyrolysis product outlet 6 to cool the gaseous oil-gas mixture, and then the condensed liquid product is collected by the subsequent liquid product collection bottle 72. The soluble gaseous product is collected by the washing bottle 73 located after the liquid product collection bottle 72. Finally, the remaining gaseous product is collected by the gas collection bag 74.

[0036] In some embodiments, the catalytic stick 2 is provided with a temperature measuring thermocouple and an air pressure sensor, and the pyrolysis reaction vessel 3 is provided with a temperature measuring thermocouple and an air pressure sensor.

[0037] In some embodiments, a plurality of the temperature measuring thermocouples are provided, and the temperature measuring thermocouples are evenly arranged on the surface of the catalytic stick 2 and the upper and lower surfaces of the pyrolysis reaction vessel 3 .

[0038] In some embodiments, a temperature measuring thermocouple is arranged every 30 cm on the surface of the catalyst stick 2.

[0039] The embodiment of the present invention provides a pyrolysis method based on the above pyrolysis device, and the method comprises the following steps:

[0040] Put the pyrolysis material into the pyrolysis reaction vessel, introduce inert gas into the superheated steam inlet, and exhaust the air in the pyrolysis device;

[0041] Introducing superheated steam into the superheated steam inlet, and adjusting the pressure regulating valve so that the pressure in the tube furnace reaches the required pressure;

[0042] The pyrolysis products are collected and processed at the pyrolysis product outlet.

[0043] The embodiment of the present invention uses superheated water vapor as a high-efficiency heat transfer medium, first prepares high-pressure superheated water vapor exceeding the set boiling point, and then uses inert gas to exhaust the air in the overall pyrolysis device. After ensuring the high-pressure airtightness of the tubular furnace, the prepared high-pressure superheated water vapor is introduced from the superheated steam inlet. There is a pressure regulating valve on the tubular furnace, which adjusts the pressure in the tubular furnace to the pressure required for the specified boiling point by pressing in inert gas, and accurately adjusts the boiling point of the superheated water vapor according to the Clausius-Clapeyron equation, and then uses the high latent heat of vaporization of the superheated water vapor to quickly perform pyrolysis at the required temperature for pyrolysis (high-temperature water vapor contacts low-temperature substances, quickly condenses into liquid, releases the stored latent heat of vaporization, and pyrolyzes the pyrolysis substances), reducing the generation of process by-products in similar slow heating processes. It has been verified that compared with the pyrolysis efficiency of traditional electric furnaces, the heating efficiency of the latent heat of vaporization of the embodiment of the present invention is increased by more than 480%, and a high temperature rise effect is generated in an instant. Among them, the Clausius-Clapeyron equation is as follows:

[0044]

[0045] P is the external pressure, T is the boiling point temperature, L is the latent heat of vaporization of the substance, and V is the mass ratio between gas and liquid. Therefore, controlling the external pressure environment can change the boiling point of the substance.

[0046] In the above scheme, when the temperature is less than 800°C, the concentration of carbon monoxide in the gasification product will be higher than that of hydrogen, and when the temperature is higher than 800°C, the concentration of hydrogen in the gasification product will be higher than that of carbon monoxide. Therefore, maintaining a high temperature state quickly and continuously is conducive to reducing the generation of process byproducts (carbon monoxide) and is also conducive to continuously increasing the production of hydrogen in a high temperature environment.

[0047] In addition, high-temperature steam can react with a variety of hydrocarbon substances under the action of different temperatures and catalysts, such as water-gas reaction, water-gas shift reaction, steam reforming reaction, and addition reaction with water, which promotes the rupture of CH bonds and generates ideal products such as hydrogen. It can also dissolve water-soluble pollutants such as HCL and polluted gases to generate substances such as hydrochloric acid that may be used. At the same time, it can react with sulfides under high-temperature catalytic conditions to remove pollution. It can also enhance the decomposition and utilization of metal sulfides and chlorination, reduce pyrolysis pollution, and increase hydrogen production by more than 5%, and generate additional products such as hydrochloric acid and sulfur.

[0048] The following is a verification of the pyrolysis efficiency, using a specific example to verify that the technology of using the latent heat of vaporization for heating greatly improves the heat exchange efficiency and rate: Comparing the heat exchange rate of the electric furnace and the water vaporization latent heat heating, assuming relevant parameters and using thermodynamic formulas for calculation. The formula for the heat exchange rate is: in, is the heat transfer rate (W), h is the heat transfer coefficient (W / m^2K), A is the heat transfer surface area (m^2), and ΔT is the temperature difference (K).

[0049] Specific calculation of heat transfer coefficient:

[0050] Plastic particles: specific heat capacity C P =0.9KJ / (kg*K), particle diameter d=5mm=0.005m (will be used as characteristic length), thermal conductivity k=0.2W / (m*K);

[0051] Inert gas (N 2 ): T 气体 =800℃, speed u = 3m / s (will be used as characteristic speed), density ρ = 0.4kg / m 3 , kinematic viscosity μ=4.2×10 -5 Pa·s, gas thermal conductivity k 气体 =0.05W / (m·K), specific heat capacity C P=1.04KJ / (kg*K);

[0052] High temperature steam: T 气体 =800°C, speed u = 3m / s (will be used as characteristic speed), density ρ = 0.25kg / m 3 , kinematic viscosity μ = 3.2 × 10 -5 Pa·s, gas thermal conductivity k 气体 =0.08W / (m·K), specific heat capacity C P =2.1KJ / (kg*K), flow rate Latent heat of vaporization L = 2257KJ / kg;

[0053] Calculation of heat transfer coefficient (h): h = N u k / d (1)

[0054] The Nusselt number (N u ): For laminar flow with Re < 2300, the empirical formula for the Nusselt number is:

[0055] N u =2+0.6·Re 0.5 ·P r 0.33 (2)

[0056] The Prandtl number (P r ): P r =C P μ / k (3)

[0057] Where Reynolds number (Re): Re = ρuL / μ (4)

[0058] Calculation shows: high temperature water vapor: Re = 117.19, nitrogen: Re = 143.

[0059] High temperature steam: P r =0.84, Nitrogen: P r =0.8736.

[0060] High temperature steam: N u =0.84, nitrogen: N u =0.8736.

[0061] Finally, from the above (1), (2), (3), (4) and various calculation results, we can get:

[0062] High temperature water vapor h=128.32W / (m 2 ·K), nitrogen h=88.3W / (m 2 ·K).

[0063] Heat transfer rate calculation The heat transfer rate of high-temperature steam includes the temperature difference heat transfer and latent heat of vaporization Nitrogen:

[0064] In some embodiments, the superheated water steam is introduced in an amount of 0.005-0.1 kg / s.

[0065] In some embodiments, the required pressure is 1.554-22.1 MPa.

[0066] In some embodiments, the pyrolysis material is one or more of polyvinyl chloride plastic, polyvinyl chloride plastic, polyethylene plastic, polypropylene plastic, polystyrene plastic, biomass waste, waste rubber, and carbon black.

[0067] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and are only for illustrating the present invention but not limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0068] Example

[0069] The pyrolysis method of polyvinyl chloride plastic comprises the following steps:

[0070] The catalyst stick, polyvinyl chloride plastic and pyrolysis reaction vessel are fixed on the pyrolysis sealing plug (seal), and placed in a tube furnace, and a thermocouple is placed in the pyrolysis material to measure the temperature at which the material is heated;

[0071] First, introduce inert gas from the superheated steam inlet for about 5 minutes to remove the remaining gas in the overall pyrolysis device and ensure the air tightness of the system;

[0072] Pre-prepare superheated steam of required temperature and pass it into the superheated steam inlet;

[0073] The relevant pyrolysis products are collected and processed at the pyrolysis product outlet.

[0074] In this embodiment, the pyrolysis products of polyvinyl chloride plastic are as follows:

[0075] Gas products: hydrocarbon gas: methane (CH 4 ), ethylene (C 2 H 4 ), propane (C 3 H 8 ), butane (C 4 H 10 ) etc.; Non-hydrocarbon gases: Hydrogen (H2 ), carbon monoxide (CO), carbon dioxide (CO 2 ); Other gases: hydrogen chloride (HCl), sulfide and other harmful gases.

[0076] Liquid products: pyrolysis oil (usually composed of polycyclic aromatic hydrocarbons, aromatic compounds, light and heavy hydrocarbons. It is a high value-added product).

[0077] Solid residue: carbon black, inorganic residue.

[0078] The above-mentioned high-temperature water vapor product adjustment scheme: high-temperature water vapor can react with a variety of hydrocarbon substances under the action of different temperatures and catalysts, causing the CH bond to break and generate ideal products such as hydrogen. It can also dissolve water-soluble pollutants such as HCL and polluted gases to generate substances such as hydrochloric acid that may be used. At the same time, it can react with sulfides under high-temperature catalytic conditions to remove pollution.

[0079] Detailed analysis of the reaction:

[0080] Reaction of water and carbon: water gas reaction C+H 2 O→CO+H 2 (Ideal product hydrogen)

[0081] Reaction of water and carbon monoxide: water gas shift reaction CO + H 2 O→CO 2 +H 2 (Ideal product hydrogen)

[0082] Water and methane (CH 4 ) reaction: Steam reforming reaction CH 4 +H 2 O→CO+3H 2 (Ideal product hydrogen)

[0083] Water and ethylene (C 2 H 4 ) reaction: addition reaction with water C 2 H 4 +H 2 O→C 2 H 5 OH (ideal product ethanol)

[0084] The reaction of water with methane and butane is similar to its reaction with methane, and a steam reforming reaction occurs to produce hydrogen or alcohols.

[0085] Polyvinyl chloride (PVC) produces hydrogen chloride HCl after thermal decomposition, which becomes hydrochloric acid after dissolving in water:

[0086]

[0087] Water vapor and sulfide: a. Water vapor and metal sulfide (such as FeS). Some metal sulfides can react with water vapor at high temperatures to form oxides or hydroxides and release hydrogen sulfide (H 2 S) Gas. b. Water vapor and non-metallic sulfide (carbon disulfide CS 2 ) reacts at high temperature or under the action of a catalyst to generate hydrogen sulfide (H 2 S) and other products. c. Water vapor and hydrogen sulfide (H 2 Hydrogen sulfide and water vapor usually do not react directly, but at high temperatures, hydrogen sulfide may be partially oxidized or cracked to form sulfur (S) and hydrogen (H 2 ) (Ideal product):

[0088] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A pyrolysis device with instantaneous high temperature rise and directional control, characterized in that: The pyrolysis device comprises a tubular furnace, a catalytic stick and a pyrolysis reaction vessel, wherein a pressure regulating valve is arranged inside the tubular furnace, and both ends of the tubular furnace are sealed by sealing members, and a superheated steam inlet and a pyrolysis product outlet are respectively provided on the sealing members at both ends of the tubular furnace; the catalytic stick is located inside the tubular furnace, one end of the catalytic stick is connected to the pyrolysis reaction vessel, and the other end is connected to the sealing member close to the superheated steam inlet, and the catalytic stick comprises a molecular sieve and a catalyst loaded on the molecular sieve; The pyrolysis device further comprises a pyrolysis product collecting device, which is connected to the tubular furnace via the pyrolysis product outlet and is used for collecting and processing the pyrolysis products.

2. The pyrolysis device according to claim 1, characterized in that: The pyrolysis product collecting device comprises a condenser, a liquid product collecting bottle, a gas washing bottle and a gas collecting bag which are connected in sequence, and the condenser is connected to the tubular furnace through the pyrolysis product outlet.

3. The pyrolysis device according to claim 1, characterized in that: The catalytic stick is provided with a temperature measuring thermocouple and an air pressure sensor, and the pyrolysis reaction vessel is provided with a temperature measuring thermocouple and an air pressure sensor.

4. The pyrolysis device according to claim 3, characterized in that: There are multiple temperature measuring thermocouples, and the temperature measuring thermocouples are evenly arranged on the surface of the catalytic stick and the upper and lower surfaces of the pyrolysis reaction vessel.

5. A pyrolysis method based on the pyrolysis device according to claim 1, characterized in that: The method comprises the following steps: Put the pyrolysis material into the pyrolysis reaction vessel, introduce inert gas into the superheated steam inlet, and exhaust the air in the pyrolysis device; Introducing superheated steam into the superheated steam inlet, and adjusting the pressure regulating valve so that the pressure in the tube furnace reaches the required pressure; The pyrolysis products are collected and processed at the pyrolysis product outlet.

6. The pyrolysis method according to claim 5, characterized in that The amount of superheated water steam introduced is 0.005-0.1 kg / s.

7. The pyrolysis method according to claim 5, characterized in that The required pressure is 1.554-22.1 MPa.

8. The pyrolysis method according to claim 5, characterized in that: The pyrolysis material is one or more of polyvinyl chloride plastic, polyvinyl chloride plastic, polyethylene plastic, polypropylene plastic, polystyrene plastic, biomass waste, waste rubber and carbon black.

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