Biomass pyrolysis system

Abstract

The invention provides a biomass pyrolysis system which comprises a pyrolysis reactor, a separator, a condenser and a separation circulation device. An outlet of the pyrolysis reactor is connected with an inlet of the separator, and an outlet of the separator is connected with an inlet of the condenser; the separation circulating device is provided with a gas inlet and a solid outlet, a radial flow turbine is mounted in the separation circulating device, the gas inlet is connected with an outlet of the condenser, and the solid outlet is connected with an inlet of the pyrolysis reactor; biomass to be pyrolyzed is subjected to pyrolysis of the pyrolysis reactor, separation of the separator and condensation treatment of the condenser in sequence, then solid is converted into a gas-liquid mixture, after the gas-liquid mixture enters the separation circulation device, solid particles and gas in the gas-liquid mixture are separated through centrifugal force generated by high-speed rotation of the radial flow type turbine, and the solid particles and the gas in the gas-liquid mixture are separated through centrifugal force generated by high-speed rotation of the radial flow type turbine. And feeding the separated solid particles into the pyrolysis reactor to be treated again. The system can improve the conversion rate of pyrolysis products of biomass.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass pyrolysis, and in particular relates to a biomass pyrolysis system. Background Art

[0002] Biomass pyrolysis is a process that converts biomass into gas, liquid fuel, and solid char under high temperature conditions. In order to better understand and optimize the biomass pyrolysis process, researchers have developed various simulation techniques to simulate and predict material conversion, heat transfer, and kinetic behavior during pyrolysis.

[0003] The system for pyrolyzing biomass can simulate and predict the process of decomposition and transformation of biomass under heating conditions, and can also provide theoretical guidance for the optimization and engineering application of biomass pyrolysis technology. The current existing simulation system is generally composed of a reactor, a separator and a condenser. The reactor is used to pyrolyze biomass to obtain pyrolysis oil and gas, and the separation device is used to remove the solid semi-coke in the pyrolysis oil and gas to reduce the tar dust content, and then the pyrolysis oil is converted into liquid through a condenser.

[0004] The existing pyrolysis biomass system is relatively simple and the product conversion rate is low. Therefore, how to improve the conversion rate of biomass has become a problem to be solved. Summary of the invention

[0005] In order to solve the problem of low conversion rate of products of existing biomass pyrolysis systems, the present invention provides a biomass pyrolysis system.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A biomass pyrolysis system, the system comprising:

[0008] Pyrolysis reactor, separator, condenser and separation cycle device:

[0009] The outlet of the pyrolysis reactor is connected to the inlet of the separator, and the outlet of the separator is connected to the inlet of the condenser;

[0010] The separation circulation device has a gas inlet and a solid outlet, a radial flow turbine is installed in the separation circulation device, the gas inlet is connected to the outlet of the condenser, and the solid outlet is connected to the inlet of the pyrolysis reactor;

[0011] The biomass to be pyrolyzed is converted from solid to gas-liquid mixture after being pyrolyzed in the pyrolysis reactor, separated in the separator and condensed in the condenser in sequence; when the gas-liquid mixture enters the separation circulation device, the solid particles and gas in the gas-liquid mixture are separated by the centrifugal force generated by the high-speed rotation of the radial flow turbine, and the separated solid particles are sent to the pyrolysis reactor for further treatment.

[0012] Preferably, the separator comprises a first separator and a second separator:

[0013] The inlet of the first separator is connected to the outlet of the pyrolysis reactor, the outlet of the first separator is connected to the inlet of the second separator, and the outlet of the second separator is connected to the inlet of the condenser;

[0014] The first separator is used for preliminarily separating the solids carried in the gas after the pyrolysis of the biomass to be pyrolyzed; the second separator is used for further separating the solids carried in the gas after the pyrolysis of the biomass to be pyrolyzed.

[0015] Preferably, it also includes:

[0016] A collecting device, wherein the inlet of the collecting device is respectively connected to the outlet of the first separator and the outlet of the second separator, and is used for collecting the solids separated by the first separator and the second separator.

[0017] Preferably, the separation circulation device also has a gas outlet, and further comprises:

[0018] A gas collecting tank, the inlet of which is connected to the gas outlet of the separation circulation device, and the gas collecting tank is used to collect the gas generated by the pyrolysis of the biomass to be pyrolyzed.

[0019] Preferably, it also includes:

[0020] A crushing device is provided, wherein the crushing device has a biomass inlet and a crushed biomass outlet, and the crushed biomass outlet is connected to the inlet of the pyrolysis reactor.

[0021] Preferably, the radial flow turbine comprises a turbine case, a guide vane and an impeller, wherein the guide vane and the impeller are installed in the turbine case, the guide vane is at the inlet of the turbine case, and the guide vane is installed above the impeller.

[0022] The biomass pyrolysis system provided by the present invention has the following beneficial effects:

[0023] Most of the solid particles are separated by the separator, and relatively pure pyrolysis oil and gas are initially obtained. However, there are still some fine particles that cannot be separated from the gas and solid. Therefore, after condensation in the condenser, the gas-liquid mixture is separated by setting up a separation circulation device and assembling a radial flow turbine. The fine raw material solid particles that have not reacted completely will gather to the outside with the liquid to achieve further gas-solid separation. The fine raw material solid particles that have not reacted completely are transported to the pyrolysis reactor again through the solid outlet for sufficient reaction, which can improve the conversion rate of the pyrolysis products of biomass. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiment of the present invention and its design scheme, the following briefly introduces the drawings required for this embodiment. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A schematic structural diagram of an existing biomass pyrolysis system provided in an embodiment of the present invention;

[0026] Figure 2 A schematic structural diagram of a biomass pyrolysis system provided by an embodiment of the present invention;

[0027] Figure 3 A schematic structural diagram of another pyrolysis system provided in an embodiment of the present invention;

[0028] Figure 4 A schematic structural diagram of a radial flow turbine provided by an embodiment of the present invention;

[0029] Figure 5 A schematic diagram comparing mass enthalpy in two cases provided in an embodiment of the present invention;

[0030] Figure 6 A schematic diagram for comparing mass flow rates during the S1 process provided by an embodiment of the present invention;

[0031] Figure 7 A schematic diagram for comparing mass flow in a gas collecting tank provided by an embodiment of the present invention;

[0032] Figure 8 A schematic diagram for comparing the enthalpy flow rate of an S1 process provided by an embodiment of the present invention;

[0033] Fig. 9 A schematic diagram for comparing enthalpy flow in a gas collecting tank provided in an embodiment of the present invention;

[0034] Fig.10 A schematic diagram for comparing total yields after a reaction in a reactor provided in an embodiment of the present invention;

[0035] Fig.11 A mass density comparison schematic diagram provided in an embodiment of the present invention;

[0036] Fig.12 A schematic diagram of mass change in each stage provided by an embodiment of the present invention;

[0037] Fig.13 A schematic diagram of solid carbon mass distribution change provided in an embodiment of the present invention.

[0038] Description of reference numerals:

[0039] R1-pyrolysis raw material inlet, R2-pyrolysis oil gas and semi-coke outlet, R3-pyrolysis oil gas and semi-coke inlet, R4-clean oil and gas outlet, R5-clean oil and gas inlet, R6-bio-oil and pyrolysis gas outlet, R7-pyrolysis gas inlet, R8-solid outlet, B1-pyrolysis reactor, B2-separator, B2-1 first separator, B2-2 second separator, B3-condenser, B4-separation circulation device, B4-1-radial turbine, B5-collecting device, B6-gas collecting tank, B7-crushing device. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention.

[0041] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the technical solutions of the present invention and simplifying the description, and do not indicate or imply 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 a limitation on the present invention.

[0042] In addition, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise clearly specified or limited, the terms "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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In the description of the present invention, unless otherwise specified, "plurality" means two or more, which will not be described in detail here.

[0043] Before introducing the solution of the present invention, the relevant background and technology involved in the present invention are first introduced.

[0044] Biomass pyrolysis technology is an important way to convert biomass into renewable energy and has broad application prospects. In the past few decades, biomass pyrolysis technology has been widely studied and applied. Through experimental and simulation methods, researchers continue to explore the basic laws and reaction mechanisms of biomass pyrolysis process, and continuously improve pyrolysis efficiency and product quality. At present, biomass pyrolysis technology has shown great application potential in the fields of bioenergy, chemicals and materials.

[0045] Although biomass pyrolysis technology has broad application prospects in the fields of energy and environment, it still faces some challenges and problems. First, the composition of biomass is complex and diverse, and its pyrolysis process involves multiple physical and chemical processes such as multiphase fluid mechanics, heat conduction, and mass transfer. The research faces complex reaction mechanisms and simulation problems. Secondly, the existing biomass pyrolysis models and software tools are still insufficient, and the accuracy and reliability of the models need to be further improved to meet the needs of engineering practice.

[0046] Biomass pyrolysis is a process that converts biomass into gas, liquid fuel, and solid char under high temperature conditions. In order to better understand and optimize the biomass pyrolysis process, researchers have developed various simulation techniques to simulate and predict material conversion, heat transfer, and kinetic behavior during pyrolysis.

[0047] The heat conduction principle is based on the heat conduction equation. By considering factors such as the size, shape and thermal conductivity of biomass particles, the temperature distribution and heat transfer of the material during heating are calculated. The material transfer principle involves mass transfer, such as the evaporation of water and the diffusion of products. The reaction kinetics principle describes the rate and transformation mechanism of the pyrolysis reaction. Through the reaction rate equation and reaction network model, the material transformation law in the biomass pyrolysis process is inferred.

[0048] The macroscopic model can predict the content of each component and the energy conversion during the pyrolysis process by establishing and solving the macroscopic equilibrium equation of the entire pyrolysis system. Commonly used macroscopic models include homogeneous models and heterogeneous models. The homogeneous model regards biomass particles as uniform materials and describes the biomass pyrolysis conversion process through homogeneous reaction rate equations. The heterogeneous model considers the non-uniform structure inside the particles and the non-uniformity of the reaction rate, and describes the material conversion during the pyrolysis process through different particle scale models.

[0049] The microscopic model starts from the particle scale and studies the pyrolysis process inside the biomass particles through numerical simulation and molecular dynamics simulation. The microscopic model can provide more detailed information such as the temperature distribution inside the particles, material transfer and reaction kinetics, but the calculation amount is large and it is suitable for studying detailed information at the particle level.

[0050] The application prospects of biomass pyrolysis process simulation technology are very broad. First of all, through simulation technology, we can deeply study the pyrolysis characteristics and mechanisms of different biomass materials, and provide a scientific basis for the selection of biomass and the optimization of process parameters. Secondly, simulation technology can optimize the design of biomass pyrolysis equipment to improve the pyrolysis efficiency and product quality of biomass. In addition, in terms of biomass energy utilization, simulation technology can help optimize the pyrolysis production process and improve the utilization efficiency and economy of biomass energy. In short, biomass pyrolysis process simulation technology has important application value and helps promote the development of biomass energy and environmental protection.

[0051] In summary, the basic principles and methods of biomass pyrolysis process simulation technology are to describe the material transformation, heat conduction and kinetic behavior of biomass pyrolysis process through heat conduction, material transfer and reaction kinetics. Macroscopic models and microscopic models are commonly used simulation methods to predict energy conversion and component changes in the pyrolysis process. Model construction foundation, model parameter acquisition, model assumptions and simplification, model stability and reliability, and model improvement and development are the key contents of simulation technology. Biomass pyrolysis process simulation technology has broad application prospects and is of great significance in the fields of bioenergy utilization and environmental protection.

[0052] Biomass pyrolysis process simulation is a method of simulating the biomass pyrolysis process by building a model and using relevant tools and software. Biomass pyrolysis process simulation involves multiple tools and software, including simulation software, chemical reaction kinetic models, and parameter fitting tools.

[0053] Simulation software is one of the basic tools for simulating the biomass pyrolysis process. Simulation software can provide numerical simulation and simulation results of the pyrolysis process, helping researchers to deeply understand the physical and chemical processes of biomass pyrolysis. Commonly used simulation software include AspenPlus, Pro Sim, etc. These software can simulate the pyrolysis process of biomass and predict and analyze the generation and distribution of pyrolysis products.

[0054] The biomass pyrolysis model is an important tool for simulating the biomass pyrolysis process. The biomass pyrolysis model can describe the characteristics of various chemical reactions in the biomass pyrolysis process and help researchers optimize the conditions and parameters of the biomass pyrolysis process. By designing simulation models for different requirements of biomass pyrolysis products, the progress of the pyrolysis reaction and the generation of products can be predicted.

[0055] Next, the construction process of the current biomass pyrolysis model (biomass pyrolysis model system) is introduced.

[0056] Figure 1 A schematic structural diagram of an existing biomass pyrolysis system provided in an embodiment of the present invention.

[0057] At present, the establishment of biomass pyrolysis process with thermodynamic model has been widely used, and AspenPlus software can be used to simulate simple processes. The modeling idea of ​​the established model is to divide the products after the reaction into two parts: solid semi-coke separation and pyrolysis oil and gas collection. The biomass first forms pyrolysis oil and gas and semi-coke in the pyrolysis stage, and then the semi-coke is separated and the pyrolysis oil and gas are condensed and extracted. The model process is also established based on this process.

[0058] The structure of the existing biomass pyrolysis system is as follows Figure 1 As shown. After the biomass enters from the feed port, it begins to fall, and the feed funnel and the screw feeder feed it into the pyrolysis reactor 1. The pyrolysis oil and gas come out from the outlet of the pyrolysis reactor 1, and enter the separator 2 through the inlet. The solid semi-coke in the pyrolysis oil and gas is removed by the separator 2, and the tar dust content is reduced, so as to further process the pyrolysis oil and gas. Subsequently, the pyrolysis oil and gas come out through the outlet, and then enter the condenser 3 through the inlet. The pyrolysis oil in the pyrolysis oil and gas is converted into liquid through the condenser 3, and discharged from the pyrolysis oil port, and finally pyrolysis gas is obtained.

[0059] The existing biomass pyrolysis system mentioned above is relatively simple. Since the solid particles of biomass only undergo one pyrolysis reaction in the reactor, when the biomass solid particles are too large or the reaction time in the system is short, there will be insufficiently reacted biomass solids. These insufficiently reacted biomass solids are not converted into pyrolysis gas, resulting in a low conversion rate of pyrolysis products. The present invention provides a biomass pyrolysis system that can improve the conversion rate of pyrolysis products.

[0060] Below, the present invention is described in detail.

[0061] Example 1

[0062] Figure 2 A schematic structural diagram of a biomass pyrolysis system provided in an embodiment of the present invention.

[0063] In the simulation process, combined with the simulation features of Aspen Plus software, the following simplifications and assumptions are made to the model:

[0064] (1) The mass flow rate of the raw materials does not change with the change of the mixing ratio.

[0065] (2) The temperature and pressure of the raw materials entering are 30°C and 50 bar respectively.

[0066] (3) The composition of the gas conforms to the ideal gas law.

[0067] (4) The main syngas components are only 12 types, namely H2O, N2, H2S, NH3, SO2, SO3, CO, CO2, H2, CH4, C2H4 and C2H6. The solids are considered as ash and unburned carbon, and the tar content is not considered.

[0068] (5) Semi-coke contains only carbon and ash, and the ash is an inert component and does not participate in any reaction.

[0069] (6) The interior of the reactor is considered to be steady-state and isothermal.

[0070] Based on the above assumptions, a pyrolysis system is established, for example, Figure 2 As shown, the pyrolysis system includes: a pyrolysis reactor B1, a separator B2, a condenser B3 and a separation circulation device B4.

[0071] The outlet of the pyrolysis reactor B1 is connected to the inlet of the separator B2, and the outlet of the separator B2 is connected to the inlet of the condenser B3.

[0072] The separation circulation device B4 has a gas inlet R7 and a solid outlet R8. The gas inlet R7 is connected to the outlet of the condenser B3, and the solid outlet R8 is connected to the inlet of the pyrolysis reactor B1.

[0073] It should be understood that the biomass to be pyrolyzed is converted from a solid into a gas-liquid mixture after being sequentially subjected to pyrolysis in the pyrolysis reactor B1, separation in the separator B2, and condensation in the condenser B3.

[0074] A radial flow turbine B4-1 is installed in the separation circulation device B4. The radial flow turbine B4-1 is used to separate solid particles in the gas-liquid mixture. When the gas-liquid mixture enters the separation circulation device B4, the centrifugal force generated by the high-speed rotation of the radial flow turbine B4-1 separates the solid particles and gas in the gas-liquid mixture, and the separated solid particles are sent to the pyrolysis reactor B1 for further processing.

[0075] Specifically, the pyrolysis reactor B1 has a pyrolysis feedstock inlet R1 and a pyrolysis oil and gas and semi-coke outlet R2.

[0076] The separator B2 has a pyrolysis oil gas and semi-coke inlet R3 and a clean oil gas outlet R4, and the pyrolysis oil gas and semi-coke inlet R3 is connected to the pyrolysis oil gas and semi-coke outlet R2 of the pyrolysis reactor. Optionally, the separator B2 is a two-stage cyclone separator.

[0077] The condenser B3 has a clean oil and gas inlet R5 and a bio-oil and pyrolysis gas outlet R6, and the clean oil and gas inlet R5 is connected to the clean oil and gas outlet R4 of the separator B2.

[0078] The separation circulation device B4 has a pyrolysis gas inlet R7 and a solid outlet R8. The pyrolysis gas inlet R7 is connected to the pyrolysis gas outlet R6 of the condenser B3, and the solid outlet R8 is connected to the pyrolysis raw material inlet R1 of the pyrolysis reactor.

[0079] Exemplarily, the biomass begins to fall after entering the pyrolysis raw material inlet R1, and is sent into the reactor B1 by the feed funnel and the screw feeder. The pyrolysis oil and gas come out of B1, and most of the solid semi-coke in the pyrolysis oil and gas is removed by the separator B2. Subsequently, the pyrolysis oil and gas pass through the condenser B3. In the later condensation stage, the gas-liquid mixture enters from the bottom of the separation circulation device B4. During the upward flow, the high-speed rotation of the radial turbine blades generates centrifugal force to separate the gas and liquid in the pyrolysis gas. The fine raw material solid particles that have not reacted completely will also gather to the outside with the liquid to achieve gas-solid separation, and the separated raw material solids are transported to the raw material inlet again under the action of the separation circulation device B4 for sufficient reaction.

[0080] In the above scheme, most of the solid particles are separated from the pyrolysis gas by a separator, and relatively pure pyrolysis oil and gas are initially obtained. However, there are still some fine particles that cannot be separated from the gas and the solid. Therefore, after condensation in the condenser, a circulation device is set up and a radial flow turbine is installed to separate the gas and liquid in the pyrolysis gas. The fine raw material solid particles that have not reacted completely will also gather to the outside with the liquid to achieve further gas-solid separation. The fine raw material solid particles that have not reacted completely are transported to the raw material inlet of the pyrolysis reactor again through the solid outlet for sufficient reaction, which can improve the conversion rate of the pyrolysis products of biomass.

[0081] Example 2

[0082] Figure 3 A schematic structural diagram of another pyrolysis system provided in an embodiment of the present invention.

[0083] Exemplarily, the system includes: a pyrolysis reactor B1, a first separator B2-1, a second separator B2-2, a condenser B3, a separation circulation device B4, a collection device B5, a gas collecting tank B6 and a crushing device B7.

[0084] Optionally, the pyrolysis reactor B1 can be a down-going bed fast pyrolysis reactor, which includes a reactor body, radiant tubes and multiple layers of baffles; there are multiple radiant tubes, which are horizontally arranged at different heights in the reactor body in the same direction, and the radiant tubes at adjacent height layers are staggered; the baffles are obliquely arranged in the reactor body, and the uppermost baffle is located at 1 / 2-2 / 3 of the height of the reactor body.

[0085] In the above scheme, a down-flow fast pyrolysis reactor is used to pyrolyze biomass, without a heat carrier, with a simple system structure, simple reaction process, convenient operation, uniform temperature distribution, high system heat rate, and good pyrolysis effect. Its internal temperature field is provided by a radiation tube, and the temperature of the drying and dehydration zone, pyrolysis reaction zone, and semi-coke generation zone is accurately adjusted by controlling different temperature zones. It has strong operability, high combustion efficiency, good energy-saving effect, and high economic benefits.

[0086] Among them, the inlet of the first separator B2-1 is connected to the outlet of the pyrolysis reactor B1, and the outlet of the first separator B2-1 is connected to the inlet of the second separator. The first separator B2-1 is used to preliminarily separate the solids carried in the gas after pyrolysis of the biomass to be pyrolyzed; the outlet of the second separator B2-2 is connected to the inlet of the condenser B3, which is used to separate the solids carried in the gas after pyrolysis of the biomass to be pyrolyzed again.

[0087] The inlet of the collecting device B5 is respectively connected to the outlet of the first separator B2-1 and the outlet of the second separator B2-2, and is used to collect the solids separated by the first separator B2-1 and the second separator B2-2.

[0088] Specifically, the collecting device B5 has a solid semi-coke inlet and a solid semi-coke outlet. The solid semi-coke inlet is connected to the solid semi-coke outlet of the separator B2 and is used to collect the solid semi-coke separated by the separator B2.

[0089] It should be understood that the solid semi-coke collected by the collecting device B5 can be used elsewhere.

[0090] The inlet of the gas collecting tank B6 is connected to the gas outlet of the separation circulation device B4, and is used to collect the gas generated by the pyrolysis of the biomass to be pyrolyzed.

[0091] Specifically, the gas collecting tank B6 has a pyrolysis gas inlet and a pyrolysis gas outlet, and the pyrolysis gas inlet is connected to the purified gas outlet of the separation circulation device B4.

[0092] The crushing device B7 has a biomass inlet and a crushed biomass outlet, and the crushed biomass outlet is connected to the inlet of the pyrolysis reactor B1.

[0093] In the above scheme, the biomass can be divided into smaller particles by the crushing device B7, so that the biomass can react more fully.

[0094] Figure 4 A schematic structural diagram of a radial flow turbine provided in an embodiment of the present invention.

[0095] Exemplarily, the radial turbine B4-1 includes a turbine case 4-1, a nozzle or guide vane 4-2, and an impeller 4-3; the guide vane 4-2 and the impeller 4-3 are installed in the turbine case 4-1, the guide vane 4-2 is at the inlet of the turbine case 4-1, and the guide vane 4-2 is installed above the impeller 4-3. The airflow direction of the radial centrifugal turbine is from the center to the outer edge, and its advantages are:

[0096] (1) Under low flow conditions, the efficiency of radial flow turbines is higher than that of axial flow turbines.

[0097] (2) The single-stage expansion ratio is large, and the turbine power of the same size is larger.

[0098] (3) Small number of blades and simple structure.

[0099] (4) The impeller is sturdy and has a high allowable speed.

[0100] (5) Ability to maintain high efficiency within a wide working range.

[0101] At the same time, the centrifugal turbine has lower aerodynamic requirements for the moving blades. Even if the blade geometry is not manufactured very accurately and the surface roughness of the blade is poor, the efficiency of the turbine will not be greatly affected. This makes it possible for us to use a relatively simple and efficient process when manufacturing the impeller. In addition, fouling on the surface of the moving blades during operation will not cause too much problem.

[0102] It should be understood that Figure 3 The S1 process shown in the figure is the process of biomass reacting from the pyrolysis raw material inlet to the reactor.

[0103] Table 1 Figure 3 An example of the reactor types and functions corresponding to some of the components.

[0104] The following describes the types and functions of some structures in the embodiment of the present invention in conjunction with Table 1.

[0105] Table 1 Reactor types and functions

[0106]

[0107] Next, the effect of this scheme is verified by comparing the data of this scheme with the existing scheme.

[0108] Enthalpy is the total heat energy contained in a unit mass of a substance. It is a parameter in thermodynamics that represents the energy state of a material system. Its calculation formula is:

[0109] h=1.005t+x(2500+1.84t)

[0110] Where: h is enthalpy; t is temperature; x is moisture content.

[0111] For a certain mass of a substance, the enthalpy value is defined as:

[0112] H=U+pV

[0113] Where U is the internal energy of the substance, p is the pressure, and V is the volume.

[0114] The enthalpy per unit mass of a substance is called mass enthalpy. By adding the separation circulation device B4, the change in mass enthalpy can be clearly seen in the generated data, such as Figure 5 As shown, Figure 5 A comparative schematic diagram of mass enthalpy provided in an embodiment of the present invention. Figure 3 The heat required for the S1 process is significantly reduced, so that the reaction can reach the reaction temperature earlier, thereby reducing the heat loss in the gas collecting tank B6. It can be seen that the heat in the pyrolysis product is fully utilized.

[0115] Mass flow rate refers to the mass of fluid passing through the effective cross section of a closed pipe or open slot per unit time. Unit: kg / h, kg / s. It corresponds to volume flow rate (volume of fluid passing per unit time).

[0116] The calculation formula for mass flow can be expressed as the product of volume flow and fluid density, that is:

[0117]

[0118] Where m is the mass flow rate, c is the volume flow rate, f is the fluid density, and v is the volume flow rate.

[0119] From the perspective of mass flow, it can also be observed that the amount of material passing through the S1 process is nearly 1200 kg / hr more than the initial amount. Figure 6 As shown, Figure 6 A schematic diagram for comparing mass flow rates during the S1 process provided by an embodiment of the present invention, wherein the material stored in the gas collecting tank B6 is relatively reduced by nearly 1 / 3. Figure 7 As shown, Figure 7 A comparative schematic diagram of mass flow in a gas collecting tank provided in an embodiment of the present invention. This phenomenon proves that under the same mass flow, the pyrolysis gas not collected by the separation circulation device B4 contains more impurities. It can be seen that the purity of the product has also been improved.

[0120] Enthalpy flow, also known as heat flow, refers to the sum of enthalpy values ​​passing through a certain cross section per unit time. Enthalpy flow is actually the rate of energy transfer or conversion, which is used to measure the speed of heat transfer in a system. The calculation formula of enthalpy flow is generally based on the first law of thermodynamics, that is, the law of conservation of energy. Specifically, it can be calculated by the following formula:

[0121] Q=m(h2-h1)

[0122] Where Q represents the enthalpy flow rate, m represents the mass flow rate, and (h2-h1) represents the difference between the enthalpy value of the fluid flowing out of the system and the enthalpy value of the fluid flowing into the system.

[0123] In the part of enthalpy flow, the enthalpy flow of S1 process in the cycle also increases by nearly 1000kW, such as Figure 8 As shown, Figure 8 A schematic diagram of the enthalpy flow rate comparison of the S1 process provided by an embodiment of the present invention, the enthalpy flow rate at the gas collecting tank B6 is also reduced by about 500kW, such as Fig. 9 As shown, Fig. 9 A comparative schematic diagram of the enthalpy flow rate in a gas collecting tank provided in an embodiment of the present invention, thereby reducing the heat loss of the entire thermal reaction device.

[0124] From the aspect of the amount of products, the separation circulation device B4 of the present invention allows more materials to fully react. Compared with the case where the separation circulation device is not installed, the total amount of materials produced by the reactor is significantly increased. Fig.10 As shown, Fig.10 A schematic diagram of the total yield comparison after the reaction in a reactor provided in an embodiment of the present invention is provided to provide further assistance for the subsequent collection and recovery of the separated substances.

[0125] The definition of mass density is the mass of a substance per unit volume. Mass density is usually represented by the Greek letter ρ (rho) and its calculation formula is:

[0126] ρ=m / V

[0127] Where m represents the mass of the substance and V represents the volume of the substance.

[0128] Mass density is a fundamental physical property of matter that describes how compact and how heavy a substance is. In physics, mass density is also called density and is a property of matter that results in different masses for the same volume, or different volumes for the same mass.

[0129] It can also be found from the comparison of mass density that Fig.11 As shown, Fig.11 A mass density comparison diagram provided for an embodiment of the present invention proves that the amount of material that has been completely reacted is significantly increased through the separation circulation device, and the stored gas contains fewer impurities.

[0130] Comparing the mass changes in the two cases, e.g. Fig.12 As shown, Fig.12A schematic diagram of mass changes in each stage provided for an embodiment of the present invention. It can be seen that the mass of the circulated process in each stage of the reaction is greater than the mass of the uncirculated process, while in the final collection stage, the collected material after the cycle is much less than the uncirculated material. This phenomenon occurs mainly because after passing through the separation circulation device, most of the solid reactant particles in the pyrolysis gas have been separated and collected, and recycled to the reaction stage. This is also the reason why the mass of each stage after the cycle increases, and the final collection is also more than the pure pyrolysis gas in the product with more impurities before the cycle.

[0131] It can be seen that by improving the original biomass pyrolysis model (system) and using a separation turbine to purify and circulate the product, the quality and purity of the obtained product are improved. This not only improves the biomass conversion rate, but also improves the working efficiency of the entire biomass pyrolysis system.

[0132] In addition, during the biomass pyrolysis process, an efficient and reliable separation and circulation device is crucial to the stable operation of the entire pyrolysis system and the quality of the generated collection. Fig.13 As shown, Fig.13 A schematic diagram of the change in the mass distribution of solid carbon provided in an embodiment of the present invention. Comparing the mass fraction of solid carbon in the two cases, it can be clearly seen that the proportion of solid carbon in each stage has decreased. This phenomenon proves that the solid biomass particles originally mixed in the pyrolysis gas are reacted again through the circulation device, which increases the enthalpy flow rate in each stage, so that part of the solid carbon undergoes chemical reaction due to the increase in reaction temperature and produces more gas, which can also increase the proportion of the required gas in the mixed gas.

[0133] It should be pointed out that the above specific implementation methods can enable those skilled in the art to understand the invention more comprehensively, but do not limit the invention in any way. Therefore, although the present specification and embodiments have described the invention in detail, those skilled in the art should understand that the invention can still be modified or replaced by equivalents; and all technical solutions and improvements that do not deviate from the spirit and scope of the invention are included in the protection scope of the patent for the invention. Any figure mark in the claims should not be regarded as limiting the claims involved. Any simple change or equivalent replacement of the technical solution that can be obviously obtained by any technician familiar with the field within the technical scope disclosed in the present invention belongs to the protection scope of the present invention.

Claims

1. A biomass pyrolysis system, characterized in that: The system comprises: a pyrolysis reactor (B1), a separator (B2), a condenser (B3) and a separation circulation device (B4): The outlet of the pyrolysis reactor (B1) is connected to the inlet of the separator (B2), and the outlet of the separator (B2) is connected to the inlet of the condenser (B3); The separation circulation device (B4) has a gas inlet (R7) and a solid outlet (R8), a radial flow turbine (B4-1) is installed in the separation circulation device (B4), the gas inlet (R7) is connected to the outlet of the condenser (B3), and the solid outlet (R8) is connected to the inlet of the pyrolysis reactor (B1); The biomass to be pyrolyzed is converted from solid to gas-liquid mixture after being subjected to pyrolysis in the pyrolysis reactor (B1), separation in the separator (B2) and condensation in the condenser (B3) in sequence; when the gas-liquid mixture enters the separation circulation device (B4), the solid particles and gas in the gas-liquid mixture are separated by the centrifugal force generated by the high-speed rotation of the radial turbine (B4-1), and the separated solid particles are sent to the pyrolysis reactor (B1) for further treatment.

2. The biomass pyrolysis system according to claim 1, characterized in that: The separator (B2) comprises a first separator (B2-1) and a second separator (B2-2): The inlet of the first separator (B2-1) is connected to the outlet of the pyrolysis reactor (B1), the outlet of the first separator (B2-1) is connected to the inlet of the second separator (B2-2), and the outlet of the second separator (B2-2) is connected to the inlet of the condenser (B3); The first separator (B2-1) is used for preliminarily separating the solids carried in the gas after pyrolysis of the biomass to be pyrolyzed; the second separator (B2-2) is used for further separating the solids carried in the gas after pyrolysis of the biomass to be pyrolyzed.

3. The biomass pyrolysis system according to claim 2, characterized in that: Also includes: A collecting device (B5), the inlet of which is respectively connected to the outlet of the first separator (B2-1) and the outlet of the second separator (B2-2), and is used to collect the solids separated by the first separator (B2-1) and the second separator (B2-2).

4. The biomass pyrolysis system according to any one of claims 1 to 3, characterized in that: The separation circulation device (B4) also has a gas outlet and includes: A gas collecting tank (B6), the inlet of which is connected to the gas outlet of the separation circulation device (B4), and the gas collecting tank (B6) is used to collect the gas generated by the pyrolysis of the biomass to be pyrolyzed.

5. The biomass pyrolysis system according to any one of claims 1 to 3, characterized in that: Also includes: A crushing device (B7), wherein the crushing device (B7) has a biomass inlet and a crushed biomass outlet, and the crushed biomass outlet is connected to the inlet of the pyrolysis reactor (B1).

6. The biomass pyrolysis system according to any one of claims 1 to 3, characterized in that: The radial flow turbine (B4-1) comprises a turbine case (4-1), a guide vane (4-2) and an impeller (4-3), wherein the guide vane (4-2) and the impeller (4-3) are installed in the turbine case (4-1), the guide vane (4-2) is at the inlet of the turbine case (4-1), and the guide vane (4-2) is installed above the impeller (4-3).

Images