阅读说明：本技术 一种高塑惰性垃圾两步催化热解制备富氢合成气的方法与装置 (Method and device for preparing hydrogen-rich synthetic gas by two-step catalytic pyrolysis of high-plasticity inert garbage ) 是由 王凯军 槐衍森 常风民 于 2020-07-02 设计创作，主要内容包括：本发明提出了一种高塑惰性垃圾两步催化热解制备富氢合成气的方法和装置,本发明的两步催化热解制备富氢合成气的方法,主要包括：1)将高塑垃圾通过连续密闭输送系统输送入一级热解炉进行中温无氧热解(450℃-600℃),主要产生挥发性产物(冷凝和非冷凝性组分)；2)将挥发性产物直接通入填充有钙/钛矿复合催化剂的二级催化热解反应炉,挥发性产物中冷凝性组分、水蒸气、CO<Sub>2</Sub>等在复合催化剂表面发生催化转化为富氢合成气(H<Sub>2</Sub>/CO)。本发明通过两步催化热解将高塑惰性垃圾转化为富氢合成气,重点解决餐厨/厨余垃圾中分选出的以轻质塑料为主的惰性垃圾热解液的能量利用及危害问题,减少高质合成气净化投资和二次污染。(The invention provides a method and a device for preparing hydrogen-rich synthetic gas by two-step catalytic pyrolysis of high-plasticity inert garbage, and the method for preparing the hydrogen-rich synthetic gas by the two-step catalytic pyrolysis mainly comprises the following steps: 1) high plastic refuse is connected throughConveying the continuous closed conveying system into a first-stage pyrolysis furnace for medium-temperature oxygen-free pyrolysis (450-600 ℃) to mainly generate volatile products (condensed and non-condensed components); 2) directly introducing the volatile product into a secondary catalytic pyrolysis reaction furnace filled with a calcium/titanium ore composite catalyst, wherein the volatile product contains condensable components, water vapor and CO 2 The catalytic conversion is carried out on the surface of the composite catalyst to obtain the hydrogen-rich synthesis gas (H) 2 /CO). The invention converts the high-plasticity inert garbage into the hydrogen-rich synthetic gas through two-step catalytic pyrolysis, mainly solves the problems of energy utilization and harm of the inert garbage pyrolysis liquid which is separated from the kitchen/kitchen garbage and mainly takes light plastics as the main component, and reduces the high-quality synthetic gas purification investment and secondary pollution.)

1. A method for preparing hydrogen-rich synthesis gas by two-step catalytic pyrolysis of high-plasticity inert garbage is characterized by comprising the following steps:

1) conveying the high-plasticity inert garbage into a first-stage medium-temperature pyrolysis furnace through a continuous closed conveying device to perform medium-temperature oxygen-free pyrolysis at 450-600 ℃ to generate a volatile product taking condensable gas and non-condensable gas as main components;

2) directly introducing the obtained volatile product into a secondary high-temperature catalytic pyrolysis furnace filled with a calcium/titanium ore composite catalyst for catalytic pyrolysis at 800-1000 ℃, wherein the volatile product contains condensable components, water vapor and CO₂The calcium/titanium ore composite catalyst is catalyzed and converted into hydrogen-rich synthesis gas on the surface.

2. The method for preparing the hydrogen-rich synthesis gas by the two-step catalytic pyrolysis of the high-plasticity inert garbage according to claim 1, wherein the high-plasticity inert garbage is plastic-rich inert garbage.

3. The method for preparing the hydrogen-rich synthesis gas by the two-step catalytic pyrolysis of the high-plasticity inert garbage according to claim 1, wherein the high-plasticity inert garbage is a light material which is separated from kitchen/kitchen garbage in a pretreatment or biological treatment process and takes plastic bags and lunch boxes as main components.

4. The method for preparing the hydrogen-rich synthesis gas by the two-step catalytic pyrolysis of the high-plasticity inert garbage according to claim 1, wherein the calcium/titanium ore composite catalyst is a composite catalyst which mainly uses calcium/titanium ore and is provided with a trace amount of Ni/Co, and is used for promoting condensable components, water vapor and CO in volatile products₂Catalytic conversion reaction takes place to produce hydrogen-rich synthesis gas.

5. The method for preparing the hydrogen-rich synthesis gas by the two-step catalytic pyrolysis of the high-plasticity inert garbage according to claim 4, wherein the loading amount of Ni/Co in the calcium/titanium ore composite catalyst is 6-7% of the total mass of the catalyst, wherein the doping ratio of Ni is 60-80%, and the doping ratio of Co is 20-40%.

6. The method for preparing the hydrogen-rich synthesis gas by the two-step catalytic pyrolysis of the high-plasticity inert garbage according to claim 1, wherein the reaction residence time in the primary medium-temperature pyrolysis furnace is 30-40 min.

7. The method for preparing the hydrogen-rich synthesis gas by the two-step catalytic pyrolysis of the high-plasticity inert garbage according to claim 1, wherein the water content of the inert garbage is adjusted to be below 15%.

8. The utility model provides a device of two-step catalytic pyrolysis preparation rich hydrogen synthetic gas of inert rubbish is moulded to height, a serial communication port, including one-level medium temperature pyrolysis oven (3) of built-in screw conveyor mechanism (2), the feed inlet that one-level medium temperature pyrolysis oven (3) is connected in airtight feed arrangement (1) supplies high inert rubbish of moulding to it, the volatile product export of one-level medium temperature pyrolysis oven (3) passes through the direct intercommunication of closed conduit with the entry of second grade high temperature catalytic pyrolysis oven (6), it has calcium/titanium ore composite catalyst (7) to fill in second grade high temperature catalytic pyrolysis oven (6), the exit linkage vapour and liquid separator (8) of second grade high temperature catalytic pyrolysis oven (6).

9. The device for preparing the hydrogen-rich synthesis gas by the two-step catalytic pyrolysis of the high-plasticity inert garbage according to claim 8, wherein the primary medium-temperature pyrolysis furnace (3) and the secondary high-temperature catalytic pyrolysis furnace (6) share one system control cabinet (5), and the reaction temperature and the starting and stopping of the feeding are controlled by the system control cabinet (5).

10. The device for preparing the hydrogen-rich synthesis gas by the two-step catalytic pyrolysis of the high-plasticity inert garbage according to claim 8, wherein a gas phase outlet of the gas-liquid separator (8) is connected with a water condenser (9), a gas phase outlet of the water condenser (9) is connected with an alkaline washing water tank (10), and a gas phase outlet of the alkaline washing water tank (10) is connected with a purifier (12) through a pipeline with an induced draft fan (11).

Technical Field

The invention belongs to the technical field of solid waste treatment, relates to resource utilization of solid waste with high plastic material content, and particularly relates to a method and a device for preparing hydrogen-rich synthesis gas by two-step catalytic pyrolysis of high-plasticity inert garbage.

Background

In the garbage classification process, the problems of firstly separating and then mixing garbage, mixing and burning kitchen garbage and the like occur due to insufficient capacity of rear-end processing facilities, and the implementation effect of garbage classification is seriously retarded. The fine treatment and resource upgrading utilization of the kitchen waste are key links for smoothly implementing waste classification. At present, the garbage classification is in a primary stage, a large amount of plastic bags, lunch boxes and the like are still mixed in the classified kitchen garbage, and the inert garbage mainly containing plastics separated in the pretreatment and biological treatment processes is difficult to treat and dispose.

The high-plasticity inert garbage can generate a large proportion of liquid phase fuel (commonly called tar) in the low-medium temperature pyrolysis process, the liquid phase fuel is a complex mixed substance consisting of hundreds of organic matters, the calorific value is about 50 percent of that of a petroleum product, and the high-plasticity inert garbage is poor in stability and difficult to directly utilize. Meanwhile, the tar is an acidic viscous liquid substance, and is extremely easy to attach to the inner walls of pipelines and equipment in actual engineering operation, so that the pipelines are blocked, the equipment is corroded, and the normal operation of the system is influenced. At present, the research on the cracking and refining of tar has a plurality of problems and bottlenecks, and has a certain distance from large-scale industrial application.

Disclosure of Invention

In order to overcome the defects of the prior art and promote the application and popularization of the high-plasticity inert garbage pyrolysis technology, the invention aims to provide the method and the device for preparing the hydrogen-rich synthetic gas by the two-step catalytic pyrolysis of the high-plasticity inert garbage, which can realize continuous feeding and discharging in a closed state and convert the high-plasticity inert garbage into the hydrogen-rich synthetic gas.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for preparing hydrogen-rich synthesis gas by two-step catalytic pyrolysis of high-plasticity inert garbage is characterized by comprising the following steps:

1) conveying the high-plasticity inert garbage into a first-stage medium-temperature pyrolysis furnace through a continuous closed conveying device to perform medium-temperature oxygen-free pyrolysis at 450-600 ℃ to generate a volatile product taking condensable gas and non-condensable gas as main components;

2) directly introducing the obtained volatile product into a secondary high-temperature catalytic pyrolysis furnace filled with a calcium/titanium ore composite catalyst for catalytic pyrolysis at 800-1000 ℃, wherein the volatile product contains condensable components, water vapor and CO₂The calcium/titanium ore composite catalyst is catalyzed and converted into hydrogen-rich synthesis gas on the surface.

The high-plastic inert garbage is inert garbage rich in plastic, and particularly is light material which is separated from kitchen/kitchen garbage in a pretreatment or biological treatment process and takes plastic bags and lunch boxes as main components.

The calcium/titanium ore composite catalyst is mainly prepared from calcium/titanium ore and trace Ni/Co, and can promote condensable components, water vapor and CO in volatile products₂Catalytic conversion reaction takes place to produce hydrogen-rich synthesis gas.

In the calcium/titanium ore composite catalyst, the load of Ni/Co accounts for 6-7% of the total mass of the catalyst, wherein the doping proportion of Ni is 60-80%, and the doping proportion of Co is 20-40%.

The reaction residence time in the first-stage medium-temperature pyrolysis furnace is 30-40 min, the residence time in the second-stage high-temperature catalytic reaction is not controlled generally, and condensable components, water vapor, CO and the like generated in the first-stage medium-temperature pyrolysis furnace₂And introducing the mixture into a secondary high-temperature catalytic pyrolysis furnace, performing steam catalytic reforming through mixed combustion, wherein the reaction time is short and is generally less than 10s, and discharging the hydrogen-rich synthetic gas after catalysis.

The invention adjusts the water content of the inert garbage to be below 15 percent, and volatile products generated by first-stage medium-temperature pyrolysisCondensed component, water vapor and CO in the product₂Catalytically converting into the required synthesis gas in suitable proportions.

The invention also provides a device for preparing the hydrogen-rich synthesis gas by two-step catalytic pyrolysis of the high-plasticity inert garbage, which comprises a primary medium-temperature pyrolysis furnace 3 internally provided with a screw conveying mechanism 2, wherein a closed feeding device 1 is connected with a feeding hole of the primary medium-temperature pyrolysis furnace 3 to supply the high-plasticity inert garbage to the feeding hole, a volatile product outlet of the primary medium-temperature pyrolysis furnace 3 is directly communicated with an inlet of a secondary high-temperature catalytic pyrolysis furnace 6 through a closed pipeline, the secondary high-temperature catalytic pyrolysis furnace 6 is filled with a calcium/titanium ore composite catalyst 7, and an outlet of the secondary high-temperature catalytic pyrolysis furnace 6 is connected with a gas-liquid separator 8.

The first-stage medium-temperature pyrolysis furnace 3 and the second-stage high-temperature catalytic pyrolysis furnace 6 share one system control cabinet 5, and the reaction temperature and the feeding start and stop of the first-stage medium-temperature pyrolysis furnace and the second-stage high-temperature catalytic pyrolysis furnace are controlled by the system control cabinet 5.

And a gas phase outlet of the gas-liquid separator 8 is connected with a water condenser 9, a gas phase outlet of the water condenser 9 is connected with an alkaline washing water tank 10, and a gas phase outlet of the alkaline washing water tank 10 is connected with a purifier 12 through a pipeline with an induced draft fan 11.

Compared with the prior art, the method has the advantages that the high-quality plastic waste is converted into volatile products (non-condensable and condensable mixed gas) through medium-temperature pyrolysis, and the volatile products are converted into the hydrogen-rich synthetic gas which can be directly utilized through high-temperature catalysis, so that utilization of pyrolysis liquid can be realized, harm of the pyrolysis liquid is relieved, and purification investment and secondary pollution of the high-quality synthetic gas are reduced.

Drawings

FIG. 1 is a schematic structural diagram of a device for preparing hydrogen-rich synthesis gas by two-step catalytic pyrolysis of high-plasticity inert garbage.

FIG. 2 is a schematic diagram showing the effect of different ratios of Ni and Co loaded on the calcium/titanium ore composite catalyst on hydrogen generation.

Detailed Description

The following detailed description of specific embodiments of the present invention and the accompanying drawings are presented for illustrative purposes and are not intended to limit the scope of the invention. All other examples obtained without inventive step by a person skilled in the art are within the scope of the invention.

The invention relates to a method for preparing hydrogen-rich synthesis gas by two-step catalytic pyrolysis of high-plasticity inert garbage, which mainly comprises the following steps:

1) conveying inert garbage rich in plastics, such as plastic bags, lunch boxes and other light materials separated from kitchen/kitchen garbage in a pretreatment or biological treatment process into a first-stage medium-temperature pyrolysis furnace through a continuous closed conveying device for medium-temperature oxygen-free pyrolysis (450-600 ℃) to generate volatile products (mainly condensable gas and non-condensable gas);

2) directly introducing the volatile product into a secondary high-temperature catalytic pyrolysis furnace filled with a calcium/titanium ore composite catalyst for catalytic pyrolysis at 800-1000 ℃, wherein the volatile product contains condensable components, water vapor and CO₂The calcium/titanium ore composite catalyst undergoes catalytic conversion on the surface of the calcium/titanium ore composite catalyst to form hydrogen-rich synthesis gas (H)₂/CO)。

In the invention, the high-plastic inert garbage is inert garbage rich in plastic, in particular to light materials which are separated from kitchen/kitchen garbage in the pretreatment or biological treatment process and take plastic bags and lunch boxes as main components.

Fig. 1 shows a specific device structure for realizing the method of the invention, which comprises a primary intermediate-temperature pyrolysis furnace 3 with a built-in screw conveying mechanism 2, wherein a closed feeding device 1 is connected with a feeding hole of the primary intermediate-temperature pyrolysis furnace 3 to supply high-plastic inert garbage to the feeding hole, and a discharging device 4 is arranged at the tail end of the primary intermediate-temperature pyrolysis furnace 3. The volatile product outlet of the first-stage medium-temperature pyrolysis furnace 3 is directly communicated with the inlet of the second-stage high-temperature catalytic pyrolysis furnace 6 through a closed pipeline, calcium/titanium ore composite catalyst 7 is filled in the second-stage high-temperature catalytic pyrolysis furnace 6, the outlet of the second-stage high-temperature catalytic pyrolysis furnace 6 is connected with a gas-liquid separator 8, the gas-phase outlet of the gas-liquid separator 8 is connected with a water condenser 9, the gas-phase outlet of the water condenser 9 is connected with an alkaline washing water tank 10, the gas-phase outlet of the alkaline washing water tank 10 is connected with a purifier 12 through a pipeline with an induced draft fan 11, the outlet of the purifier is connected with a gas storage tank 13, the first-stage medium-temperature pyrolysis furnace 3 and the second-stage high-temperature catalytic pyrolysis furnace 6 can share one system control cabinet.

In this embodiment, pipeline pyrolysis furnace is adopted to one-level medium temperature pyrolysis furnace 3, and the material relies on screw conveyor 2 to carry, and 1 main part of airtight feed arrangement is feeding storage box, and feeding inlet and discharge gate of feeding storage box all have the valve.

The device is used for preparing the hydrogen-rich synthesis gas by two-step catalytic pyrolysis of high-plasticity inert garbage, and comprises the following specific steps:

1. preparing a calcium/titanium ore composite catalyst which mainly comprises calcium/titanium ore and is provided with trace Co/Ni and the like, filling a proper amount of the calcium/titanium ore composite catalyst into the secondary high-temperature catalytic pyrolysis furnace 6, and adjusting to ensure that the primary medium-temperature pyrolysis furnace 3 and the secondary high-temperature catalytic pyrolysis furnace 6 are in an optimized stable state.

Wherein the calcium/titanium ore composite catalyst is mainly calcium/titanium ore and is provided with trace Ni/Co composite catalyst and the like, and can promote condensable components, water vapor, CO and the like in volatile products₂And carrying out catalytic conversion reaction to generate hydrogen-rich synthesis gas. In the embodiment, a lemon complex impregnation method is adopted to prepare the supported perovskite catalyst, and the load capacity of Ni/Co is 6-7% of the total mass of the catalyst, wherein the Ni doping proportion ranges from 60-80%, and the Co doping proportion ranges from 20-40%. By comparing the Ni and Co loaded in different proportions, the Ni and Co doped with 80% and 20% have higher selectivity for hydrogen generation. The experimental results are shown in FIG. 2, in which LaNiO₃/γ-Al₂O₃The catalyst A, B was doped with Ni/Co in a 6% mass fraction.

2. When the furnace temperature of the first-stage medium-temperature pyrolysis furnace 3 reaches a medium-temperature state (450 ℃ -600 ℃) and the furnace temperature of the second-stage high-temperature catalytic pyrolysis furnace 6 reaches a high-temperature state (800 ℃ -900 ℃), the dried high-plastic inert garbage (with the water content of 10% -20%) is put into the closed feeding device 1.

3. And opening an upper end feed port valve of the closed feeding device 1, enabling the materials to enter a feeding storage box, opening a lower end discharge port valve, closing the upper end feed port valve, and ensuring that the closed feeding device 1 is in a sealing state.

4. The temperature controller and the conveying motor of the spiral conveying mechanism 2 are adjusted through the system control cabinet 5, and the furnace temperature of the first-stage medium-temperature pyrolysis furnace 3 is controlled to be in a medium-temperature state and the appropriate material retention time (30min-40 min).

5. Volatile products (condensed and non-condensable gases) generated by pyrolysis in the first-stage medium-temperature pyrolysis furnace 3 directly enter the second-stage high-temperature catalytic pyrolysis furnace 6, the temperature of the second-stage high-temperature catalytic pyrolysis furnace 6 is controlled to be in a high-temperature state through a second-stage temperature controller, the residence time of the second-stage high-temperature catalytic reaction is generally not controlled, condensable components, water vapor and CO2 generated in the first-stage medium-temperature pyrolysis furnace are introduced into the second-stage high-temperature catalytic pyrolysis furnace, steam catalytic reforming is generated through mixed combustion, the reaction time is short and is generally less than 10s, and the hydrogen-rich synthetic gas is discharged after catalysis.

6. By adjusting the water content of the inert garbage to be below 15%, condensed components, water vapor and CO in volatile products generated by first-stage medium-temperature pyrolysis are condensed₂Catalytically converting into the required synthesis gas;

7. the synthesis gas generated by the secondary catalytic pyrolysis enters a gas storage tank 13 through a gas-liquid separator 8, a water condenser 9, an alkaline washing water tank 10 and a purifier 12 (a deep purification drying box), and can be directly used as fuel gas or high-quality chemical raw materials.

Taking the plastic waste separated from kitchen waste/kitchen waste as an example, the kitchen waste high-plastic inert waste is rich in hydrogen synthesis gas (H) under the action of the operation condition of a first-stage medium-temperature pyrolysis reaction furnace of 500 ℃/30min, the temperature of a second-stage pyrolysis reaction furnace of 900 ℃ and the catalyst of a calcium/titanium ore composite catalyst₂+ CO) gas proportion greater than 90%, where H₂The proportion is more than 70 percent.

The invention respectively compares thermogravimetric analysis (plastics, bones and refractory materials) of kitchen waste sorting substances with different component proportions, and thermogravimetric experiments show that all the components are basically not reduced in weight at 600 ℃, so that the organic matter of the sample is basically cracked and finished at 600 ℃. The materials used in the experiment are taken from a kitchen waste treatment center in a certain market, and organic wastes obtained after the kitchen waste is separated in a normal state are adopted. The primary pyrolysis temperature was controlled at 600 ℃ at which time all components had completed cracking. Experiments mainly compare H in different catalysts and at different catalytic temperatures₂The results are as follows:

from the experimental results, it can be seen that H increases with temperature₂The yield of CO is gradually increased, at 900 ℃ using LaNi_0.8Co_0.2O₃/γ-Al₂O₃Catalyst, synthesis gas (H) in gas phase product₂The + CO) ratio reaches a maximum of 98%, H₂The maximum yield was 72%.

In conclusion, the invention converts the high-plastic inert garbage into the hydrogen-rich synthetic gas through two-step catalytic pyrolysis, mainly solves the problems of energy utilization and harm of the inert garbage pyrolysis liquid which is separated from the kitchen/kitchen garbage and mainly takes light plastic as the main material, and reduces the purification investment and secondary pollution of the high-quality synthetic gas.