CN113214851A - Straw internal heating moving bed pyrolysis equipment and method based on in-situ reforming - Google Patents

Abstract

The invention discloses in-situ reforming-based straw internal heating moving bed pyrolysis equipment and a method, and the equipment comprises a feed hopper, a furnace body, a carbon discharge screw, a burner and a triple condenser, wherein a feeding conveyer belt is arranged below the feed hopper, the tail end of the feeding conveyer belt corresponds to a feed inlet of the furnace body, and the lower part of the furnace body is provided with an ignition port; the bottom of the furnace body is provided with a stirring mechanism and a discharging mechanism; the furnace body is also provided with a pyrolysis gas upper outlet, a pyrolysis gas lower outlet and a pyrolysis gas reflux port; a charcoal outlet is formed in the bottom of the furnace body, an outlet in the bottom of the charcoal outlet is connected with a charcoal outlet screw, a charcoal conveying belt is arranged below the charcoal outlet screw, and the charcoal conveying belt is connected to a charcoal box; the tail part of the discharge pipeline is respectively connected with the combustor and the triple condenser through branch pipelines, and the tail end of the triple condenser is connected with a tail gas treatment device. The biochar generated as a product can be catalyzed in situ, and the catalyst does not need to be replaced frequently; the carbon gas in-situ coupling reforming process is adopted, so that the influence caused by tar is greatly reduced.

Description

Straw internal heating moving bed pyrolysis equipment and method based on in-situ reforming

Technical Field

The invention relates to the technical field of coal chemical industry, in particular to straw internal heating moving bed pyrolysis equipment and method based on in-situ reforming.

Background

At present, the main products generated by the pyrolysis process are biochar, pyrolysis gas and tar, wherein the biochar and the pyrolysis gas are high-value energy products and are often influenced by the tar to cause the reduction of the calorific value of the biochar and the tar. The characteristic of material movement in the vertical moving bed easily causes uneven distribution of a raw material layer in the furnace body and uneven final carbonization; and the problem that the continuous action time of the catalyst in the furnace body is short is easily caused due to the influence of the structure of the furnace body, so that the continuous reaction is influenced.

Patent number CN206911014U has proposed an utilize granule semicoke to carry out prefiltering's process units to pyrolysis gas, and the device utilizes the semicoke that self generated to carry out the reforming filtration to pyrolysis gas, can effectively reduce the particulate content in the pyrolysis gas, and the smooth of the rear portion process of being convenient for goes on. Although this device is through utilizing granule semicoke to carry out prefiltration to pyrolysis gas, particulate matter content in the pyrolysis gas can be reduced greatly, helps alleviateing the burden of relevant process in rear portion, improves the reliability of process system operation. But this patent does not include whole pyrolysis process, and simple filter equipment only solves the problem that probably exists in the whole in-process of pyrolysis inadequately, and receives its functional influence, leads to the device structure complicacy, and the cost is higher.

Patent No. CN110982555A proposes a reforming reaction device for catalytic pyrolysis of biomass tar, which mainly comprises a fixed bed and a spouted bed. This patent proposes a reforming reaction route in which the fluidizing gas generated in a fixed bed is introduced into a spouted bed through a separator from an external line, and the catalyst passing therethrough is finally discharged from the upper portion. Although the effect of the reforming reaction is improved by the route, the problem that the tar content exceeds the standard is not thoroughly solved, the tar still needs to be further removed in the application of the product, and the catalyst is difficult to regenerate in a spouted bed, so that the problem of poor continuous operability and the like can also exist.

The existing vertical moving bed pyrolysis furnace has the problem of short continuous action time of the catalyst under the continuous operation condition, and although other catalysts can be used for improving the catalytic activity, the problem that the reaction is difficult to carry out after the effective duration time is over is still not really improved; in most cases, the problem of high tar content still exists in the product after reforming, the tar problem is not really solved, and meanwhile, although most of moving bed pyrolysis furnaces have a certain reforming effect, the whole reforming process is uncontrollable, so that the effective reforming is difficult to ensure; in addition, the problems of poor stirring performance of raw materials in the furnace, easy slag bonding and the like still exist.

Disclosure of Invention

The invention aims to provide straw internally-heated moving bed pyrolysis equipment and method based on in-situ reforming, which are used for solving the problems in the prior art, greatly reducing the influence of tar on products and improving the physical and chemical properties of biochar and pyrolysis gas.

In order to achieve the purpose, the invention provides the following scheme: the invention provides a straw internal heating moving bed pyrolysis device based on in-situ reforming, which comprises a feed hopper, a furnace body, a carbon discharge spiral, a burner and a triple condenser,

a feeding conveyer belt is arranged below the feeding hopper, the tail end of the feeding conveyer belt driven by a motor corresponds to a feeding hole above the furnace body, and an ignition port is arranged at the lower part of the furnace body; the bottom of the furnace body is provided with a stirring mechanism and a discharging mechanism which rotate in the same direction; the furnace body is also provided with an upper pyrolysis gas outlet, a lower pyrolysis gas outlet and a pyrolysis gas reflux opening which are connected by a discharge pipeline, and the flow at the pyrolysis gas reflux opening can be regulated and controlled by an electromagnetic valve; a charcoal outlet is formed in the bottom of the furnace body, an outlet in the bottom of the charcoal outlet is connected with a charcoal outlet screw, a charcoal conveying belt is arranged below the charcoal outlet screw, and the charcoal conveying belt is connected to a charcoal box; the tail part of the discharge pipeline is respectively connected with the combustor and the triple condenser through branch pipelines, and the tail end of the triple condenser is connected with a tail gas treatment device.

Preferably, an air inlet connected with the blower is formed in the side wall of the lower part of the furnace body.

Preferably, the air inlet is communicated with an air distribution mechanism in the furnace body.

Preferably, the rotating directions of the stirring mechanism and the discharging mechanism are both clockwise.

Preferably, the number of the carbon outlets below the furnace body is four, each carbon outlet is connected with a carbon outlet tee, and a bottom outlet of the carbon outlet tee is connected with a carbon outlet spiral.

Preferably, a water inlet net port and a water outlet net port are additionally arranged at two ends of the charcoal outlet spiral.

Preferably, a gas sampling port is formed on a branch pipeline connecting the discharge pipeline and the combustor.

The pyrolysis method applied to the straw internally-heated moving bed pyrolysis equipment based on in-situ reforming comprises the following four stages:

(1) and (3) an ignition stage: fill the raw materials to the feeder hopper, make the raw materials fall into the material loading conveyer belt to the below through feeder hopper below opening, use motor drive material loading conveyer belt to deliver to the feed inlet department of furnace body top with the raw materials, it reaches to be enough to carry out the operation to last to the material level in the furnace body, can stop the feeding process this moment, prepare to ignite, the air circulation route is in the furnace body: the ignition port, the air inlet, the blower and the ignition port judge the opening and closing of the feeding conveyer belt by monitoring the material level to ensure the sufficiency of the raw materials;

(2) and (3) a stable combustion stage: when the temperature in the furnace rises to the reaction temperature and keeps stable, the reaction in the furnace enters a stable combustion stage, a stirring mechanism and a discharging mechanism at the bottom of the furnace body are opened, the stirring mechanism and the discharging mechanism rotate clockwise to observe the temperature in the furnace to control the reaction condition in the furnace, and the switch of a blower is adjusted according to whether the temperature is in combustion supporting state or not;

(3) an in-situ reforming stage: pyrolysis gas in the pyrolysis process is discharged through a pyrolysis gas upper outlet and a pyrolysis gas lower outlet on the furnace body through pipelines, or returns to the furnace through a pyrolysis gas return port;

(4) product discharge stage:

1) collecting the biochar: discharging charcoal through a bottom discharging mechanism, discharging charcoal from four charcoal outlets below the furnace body, connecting a charcoal outlet tee to the charcoal outlets, connecting a charcoal outlet screw to a bottom outlet, dropping the cooled charcoal onto a charcoal conveyer belt below, and conveying the charcoal into a charcoal box for drying and storage;

2) and (3) collection of pyrolysis gas: the reformed pyrolysis gas passes through the branch pipeline at the tail part, one path of pyrolysis gas enters the combustor to be combusted, the other path of pyrolysis gas enters the triple condenser to be subjected to multistage condensation, and therefore purification is carried out again, and the purified pyrolysis gas is collected and utilized through the tail gas treatment device.

Compared with the prior art, the invention has the following beneficial technical effects:

1. the invention adopts a carbon gas in-situ coupling reforming process, can greatly reduce the influence of tar on products, integrally regulate and control the progress of reforming reaction, and improve the physical and chemical properties of biochar and pyrolysis gas.

2. The invention adopts a special vertical moving bed pyrolysis reactor which can provide the environment required by the carbon gas in-situ coupling reforming process, improves the reaction efficiency, has a simple structure and is easy to popularize and apply on an industrial scale.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of the overall structure of a straw internally-heated moving bed pyrolysis device based on in-situ reforming;

FIG. 2 is a flow chart of a carbon gas in-situ coupling reforming pyrolysis process;

the device comprises a feed hopper 1, a feeding conveyer belt 2, an annular pyrolysis gas upper outlet 3, an annular pyrolysis gas lower outlet 4, a stirring mechanism 5, an annular air distribution port 6, an air distribution mechanism 7, an ignition port 8, a power shaft 9, a discharging mechanism 10, a pressure stabilizing exhaust port 11, a feed inlet 12, a pyrolysis gas upper outlet 13, a pyrolysis gas lower outlet 14, an upper air inlet 15, a lower air inlet 16, a pyrolysis gas reflux port 17, an air blower 18, an induced draft fan 19, a gas sampling port 20, a burner 21, a burner support 22, a tail gas treatment device 23, a triple condenser 24, a water inlet net port 25, a carbon outlet spiral 26, a water outlet net port 27, a biochar conveyer belt 28 and a carbon box 29.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide straw internally-heated moving bed pyrolysis equipment and method based on in-situ reforming, which are used for solving the problems in the prior art, greatly reducing the influence of tar on products and improving the physical and chemical properties of biochar and pyrolysis gas.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1-2, the present embodiment provides an in-situ reforming-based straw internally-heated moving bed pyrolysis apparatus and method, including a feed hopper 1, a furnace body, a char-forming screw 26, a burner 21 and a triple condenser 24;

specifically, a feeding conveyer belt 2 is arranged below the feeding hopper 1, the tail end of the feeding conveyer belt 2 driven by a motor corresponds to a feeding hole 12 above the furnace body, and an ignition port 8 is arranged at the lower part of the furnace body; the bottom of the furnace body is provided with a stirring mechanism 5 and a discharging mechanism 10 which rotate in the same direction; the furnace body is also provided with an upper pyrolysis gas outlet 13, a lower pyrolysis gas outlet 14 and a return opening 17 of the pyrolysis gas, which are connected by a discharge pipeline, and the flow at the return opening 17 of the pyrolysis gas can be accurately regulated and controlled by an electromagnetic valve; a charcoal outlet is formed in the bottom of the furnace body, an outlet in the bottom of the charcoal outlet is connected with a charcoal outlet screw 26, a charcoal conveying belt 28 is arranged below the charcoal outlet screw 26, and the charcoal conveying belt 28 is connected with a charcoal box 29; the tail part of the discharge pipeline is respectively connected with the combustor 21 and the triple condenser 24 through branch pipelines, and the tail end of the triple condenser 24 is connected with the tail gas treatment device 23.

The invention adopts the pyrolysis process of in-situ coupling and reforming of carbon gas, solves the problems of the existing pyrolysis equipment by improving the quality of pyrolysis gas and biochar, and specifically adopts the following processes: after the raw materials enter the furnace body, the clean pyrolysis gas and the biochar with high calorific value are obtained through the steps of drying, baking, pyrolysis, reforming, discharging and the like. Wherein, the reforming refers to the process that the returned pyrolysis gas is decoked through the biochar in the furnace, thereby improving the quality of the pyrolysis gas and the biochar. The biochar produced by the process is influenced by high-temperature pyrolysis gas, the surface porosity and the specific surface area of the biochar are changed, and impurities contained in the pyrolysis gas are purified due to the influence of the adsorption effect of the biochar, so that the quality of the pyrolysis gas is improved. The process flow adopted is shown in figure 2.

The working principle of the method is explained by combining the figure 1 and the figure 2, and the method is mainly divided into four stages of ignition, stable combustion, in-situ reforming and product discharge:

(1) and (3) an ignition stage: fill raw materials to feeder hopper 1, make the raw materials fall into to the material loading conveyer belt 2 of below through feeder hopper below opening, use motor drive conveyer belt to deliver to the raw materials to the 12 departments of feed inlet above the furnace body, it reaches to be enough to carry out the operation to the material level in the furnace body to last, can stop the feeding process this moment, prepare to ignite, guarantee during the ignition that the furnace body can constitute air cycle inside and outside the furnace body, in order to guarantee to have sufficient oxygen, make the ignition stage go on smoothly, wherein, the air cycle route is: ignition port 8-air inlet 15 and air inlet 16-blower 18-ignition port 8. The switch of the feeding conveyer belt 2 is judged by monitoring the material level, so that the sufficiency of the raw materials is ensured.

(2) And (3) a stable combustion stage: when the temperature in the furnace rises to the reaction temperature and keeps stable, the reaction in the furnace enters a stable combustion stage, and the stirring mechanism 5 and the discharging mechanism 10 at the bottom of the furnace body are opened to rotate clockwise to form a double-stirring effect, so that the slag bonding in the furnace is prevented, and the uniformity of the pyrolysis in the furnace is ensured. During the period, the furnace body needs to be kept in a micro negative pressure state, the temperature in the furnace is observed to control the reaction condition in the furnace, and the switch of the blower 18 is adjusted according to whether combustion is needed or not.

(3) An in-situ reforming stage: pyrolysis gas in the pyrolysis process is discharged through a pipeline through a pyrolysis gas upper outlet 13 and a pyrolysis gas lower outlet 14 on the furnace body, part of the pyrolysis gas returns to the furnace through a pyrolysis gas return port 17, the pyrolysis gas is uniformly conveyed into the furnace through an air distribution mechanism 7 in the furnace body, the pyrolysis gas is subjected to catalytic reforming through carbon in the furnace body, impurities such as tar and the like are removed, the pyrolysis gas is discharged through a pyrolysis gas outlet again, and the discharged and returned pyrolysis gas can be controlled through an electromagnetic valve, so that the process of in-situ coupling reforming of the carbon gas can be integrally regulated and controlled. At the moment, the biochar is influenced by high-temperature pyrolysis gas, and the physical and chemical properties are changed, so that the properties of pyrolysis products are changed, and the purpose of quality improvement is achieved.

(4) Product discharge stage: after the whole pyrolysis reaction, the biochar and pyrolysis gas generated by the reaction are collected, and different collection modes are adopted according to the characteristics of different products.

Collecting the biochar: promote the row charcoal anticlockwise via bottom discharge mechanism 10, go out the charcoal by four carbon outlets in furnace body below, connect out the charcoal tee bend at a carbon outlet, bottom exit linkage goes out charcoal spiral 26 to install into water inlet net mouth 25 and play water net mouth 27 additional at a charcoal spiral 26 both ends, be used for cooling down the biological charcoal that just goes out the furnace body, afterwards, on the charcoal that falls into the biological charcoal conveyer belt 28 of below through the cooling, carry into dry storage in the charcoal case 29.

And (3) collection of pyrolysis gas: through the branch pipeline of afterbody, partly pyrolysis gas gets into combustor 21 and carries out the combustion processing through the pyrolysis gas of reforming, has added extra gas sample mouth 20 simultaneously on this part pipeline, conveniently collects the analysis to the pyrolysis gas after the reforming, and another part pyrolysis gas gets into triple condenser 24 and carries out multistage condensation to purify once more, the pyrolysis gas after purifying is collected the utilization via tail gas processing apparatus 23.

According to the in-situ reforming-based straw internal heating moving bed pyrolysis equipment and method, biochar generated as a product can be catalyzed in situ, and the catalyst does not need to be replaced frequently; the carbon gas in-situ coupling reforming process is adopted, so that the influence caused by tar is greatly reduced; two electromagnetic valves are adopted to control the flow of the discharged and refluxed pyrolysis gas, and the integral reforming reaction is regulated and controlled. The furnace body is internally provided with multi-stage stirring, so that the slagging phenomenon can be avoided to the greatest extent.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not intended to be construed as limiting the claim concerned.

The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (8)

1. The utility model provides a straw internal heating removes bed pyrolysis equipment based on normal position reforming which characterized in that: comprises a feed hopper, a furnace body, a carbon discharge screw, a burner and a triple condenser,

a feeding conveyer belt is arranged below the feeding hopper, the tail end of the feeding conveyer belt driven by a motor corresponds to a feeding hole above the furnace body, and an ignition port is arranged at the lower part of the furnace body; the bottom of the furnace body is provided with a stirring mechanism and a discharging mechanism which rotate in the same direction; the furnace body is also provided with an upper pyrolysis gas outlet, a lower pyrolysis gas outlet and a pyrolysis gas return port which are connected with the discharge pipeline, and the flow at the pyrolysis gas return port can be regulated and controlled through an electromagnetic valve; a charcoal outlet is formed in the bottom of the furnace body, an outlet in the bottom of the charcoal outlet is connected with a charcoal outlet screw, a charcoal conveying belt is arranged below the charcoal outlet screw, and the charcoal conveying belt is connected to a charcoal box; the tail part of the discharge pipeline is respectively connected with the combustor and the triple condenser through branch pipelines, and the tail end of the triple condenser is connected with a tail gas treatment device.

2. The in-situ reforming based straw internally heated moving bed pyrolysis apparatus as claimed in claim 1, wherein: and an air inlet connected with the air blower is formed in the side wall of the lower part of the furnace body.

3. The in-situ reforming based straw internally heated moving bed pyrolysis apparatus as claimed in claim 2, wherein: the air inlet is communicated with an air distribution mechanism in the furnace body.

4. The in-situ reforming based straw internally heated moving bed pyrolysis apparatus as claimed in claim 1, wherein: the rotating directions of the stirring mechanism and the discharging mechanism are both clockwise.

5. The in-situ reforming based straw internally heated moving bed pyrolysis apparatus as claimed in claim 1, wherein: the number of the carbon outlets below the furnace body is four, each carbon outlet is connected with a carbon outlet tee, and a bottom outlet of the carbon outlet tee is connected with a carbon outlet screw.

6. The in-situ reforming based straw internally heated moving bed pyrolysis apparatus as claimed in claim 1, wherein: the two ends of the charcoal outlet spiral are respectively provided with a water inlet net port and a water outlet net port.

7. The in-situ reforming based straw internally heated moving bed pyrolysis apparatus as claimed in claim 1, wherein: and a gas sampling port is formed in a branch pipeline connecting the discharge pipeline and the combustor.

8. An in-situ reforming-based straw internally-heated moving bed pyrolysis method applied to the in-situ reforming-based straw internally-heated moving bed pyrolysis equipment in any one of claims 1 to 7, which is characterized by comprising the following four stages:

(1) and (3) an ignition stage: filling raw materials into a feed hopper, enabling the raw materials to fall into a feeding conveyer belt below through an opening below the feed hopper, driving the feeding conveyer belt by using a motor to convey the raw materials to a feeding port above a furnace body, continuously feeding until the material level in the furnace body meets the requirement, stopping the feeding process at the moment, and preparing for ignition;

(2) and (3) a stable combustion stage: when the temperature in the furnace rises to the reaction temperature and keeps stable, the reaction in the furnace enters a stable combustion stage, a stirring mechanism and a discharging mechanism at the bottom of the furnace body are opened, the stirring mechanism and the discharging mechanism rotate clockwise to observe the temperature in the furnace to control the reaction condition in the furnace, and the switch of a blower is adjusted according to whether combustion supporting is needed or not;

(3) an in-situ reforming stage: pyrolysis gas in the pyrolysis process is discharged through a pyrolysis gas upper outlet and a pyrolysis gas lower outlet on the furnace body through pipelines or returns to the furnace through a pyrolysis gas return port;

(4) product discharge stage:

1) collecting the biochar: discharging charcoal through a bottom discharging mechanism, discharging charcoal from four charcoal outlets below the furnace body, connecting a charcoal outlet tee to the charcoal outlets, connecting a charcoal outlet screw to a bottom outlet, dropping the cooled charcoal onto a charcoal conveyer belt below, and conveying the charcoal into a charcoal box for drying and storage;

2) and (3) collection of pyrolysis gas: the reformed pyrolysis gas passes through the branch pipeline at the tail part, one path of pyrolysis gas enters the combustor to be combusted, the other path of pyrolysis gas enters the triple condenser to be subjected to multistage condensation, and therefore purification is carried out again, and the purified pyrolysis gas is collected and utilized through the tail gas treatment device.

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