A biomass pyrolysis combustible gas water vapor catalytic de-tar device

Abstract

The application discloses a biomass pyrolysis combustible gas water vapor catalytic tar removal equipment, comprising: a pretreater, including a cooling dust remover, a calcinator and a water vapor mixer, the outlet of the cooling dust remover and the outlet of the calcinator are connected with two inlets of the water vapor mixer through treatment pipelines; a catalytic bed, including an air inlet layer, a main catalytic bed, a standby catalytic bed and an air outlet layer; a catalytic pyrolysis reactor, including a filter dust remover and a pyrolysis device, the outlet of the air outlet layer is connected with the inlet of the filter dust remover; a post-treater, including a cyclone dust remover and a quencher, the outlet of the pyrolysis device is connected with the inlet of the cyclone dust remover, and the outlet of the cyclone dust remover is connected with the inlet of the quencher. The water vapor catalytic tar removal equipment is simple in equipment assembly, easy in process control of each equipment, convenient in catalyst regeneration in the catalytic bed, and capable of preventing equipment blockage and corrosion by carrying out dust removal on combustible gas in intervals, and is particularly suitable for small enterprise project production.

Description

Technical Field

[0001] This invention belongs to the field of catalytic decoking technology, and particularly relates to a steam catalytic decoking device for biomass pyrolysis combustible gas. Background Technology

[0002] Biomass (straw, sawdust, agricultural and forestry waste, etc.) pyrolysis combustible gas is a mixed combustible gas generated by the thermal pyrolysis of biomass under anaerobic / oxygen-deficient conditions. Its core components are CO, H2, and CH4, while the non-combustible components are CO2, H2O, and N2 (when air is gasified). It contains impurities such as tar and sulfides, and has a calorific value of approximately 12–16 MJ / m³ (medium calorific value). It can be used for heating, power generation, and the production of green hydrogen / green methanol, and is a typical renewable gas.

[0003] Tar, an impurity in the combustible gas produced during biomass pyrolysis, is a core obstacle affecting system stability, equipment lifespan, environmental emissions, and energy efficiency. For example, tar can cause condensation and blockage of gas passages and equipment, corrode metal components, reduce the calorific value and combustion efficiency of the gas, severely damage internal combustion engines and gas turbines, and produce pollutants such as black smoke and polycyclic aromatic hydrocarbons. This significantly increases operation and maintenance costs, poisons catalysts, and hinders chemical utilization. Therefore, the combustible gas produced during biomass pyrolysis requires decoking treatment.

[0004] Existing methods for removing tar from biomass pyrolysis gas require a combination of "source reduction, mid-stream purification, and end-of-pipe deep treatment." Among these, steam catalytic decoking is currently the most advanced, cleanest, and most suitable tar removal technology for high-end applications. It can deeply remove tar, improve quality and increase hydrogen production, and produce almost no secondary pollution. It is the core technology for the industrialization of biomass combustible gas. However, this technology also has disadvantages such as large equipment investment, easy carbon buildup requiring frequent regeneration, complex process control, and severe high-temperature corrosion. Its economic viability is severely limited in small-scale, low-cost biomass pyrolysis projects with complex raw materials.

[0005] Therefore, it is necessary to propose a steam catalytic detarting device for biomass pyrolysis combustible gas to solve the above problems. Summary of the Invention

[0006] The technical problem to be solved by this invention is to address the problems of existing biomass pyrolysis combustible gas steam catalytic detarting equipment, such as large investment, easy carbon accumulation requiring frequent regeneration, sensitivity to sulfur, chlorine, alkali metals, complex process control, and severe high-temperature corrosion. A new biomass pyrolysis combustible gas steam catalytic detarting equipment is proposed.

[0007] To address the aforementioned technical problems, this invention provides a steam catalytic detarting device for biomass pyrolysis combustible gas, comprising:

[0008] The preprocessor includes a cooling dust collector, a calciner, and a water-gas mixer. The outlets of the cooling dust collector and the calciner are respectively connected to the two inlets of the water-gas mixer through processing pipes. Electrically controlled valves are installed on the processing pipes.

[0009] Pretreatment can initially remove dust and cool down charcoal-containing combustible gases;

[0010] Water is heated in the calciner and calcined into superheated steam at 800°C. The ratio of water vapor to fuel gas is 1:1, and the steam is premixed with the fuel gas.

[0011] The catalytic bed, from bottom to top, includes an inlet layer, a main catalytic bed and a backup catalytic bed arranged in parallel, and an outlet layer. The outlet of the water-vapor mixer is connected to the inlet of the inlet layer. The two outlets of the inlet layer are connected to the inlets of the main catalytic bed and the backup catalytic bed, respectively. The inlet and outlet of the main catalytic bed and the backup catalytic bed are equipped with inlet valves and outlet valves. The outlets of the main catalytic bed and the backup catalytic bed are connected to the outlet layer.

[0012] Under the action of the catalyst (Ni / Al2O3, dolomite, noble metals, etc.) on the surface of the catalyst in the catalytic bed, tar macromolecules, H2O, and hydrocarbons are adsorbed onto the active sites of the catalyst, and then H2O dissociates into active free radicals ·H and ·OH, and the C–C and C–H bonds of tar are weakened and activated.

[0013] The catalytic cracking reactor includes a filter dust collector and a cracker. The outlet of the gas vent is connected to the inlet of the filter dust collector, and the outlet of the filter dust collector is connected to the inlet of the cracker. The reflux port on the bottom side of the cracker is connected to the top inlet of the water-gas mixer through a reflux pipe. An electrically controlled valve is installed on the reflux pipe.

[0014] The filter dust collector in the catalytic cracking reactor first removes dust from the combustible gas coming out of the catalytic bed, and then it enters the cracker to carry out the catalytic cracking reaction. The catalytic cracking reaction is: large molecule tar → small molecule hydrocarbons, olefins, aromatics, coke; conditions: 700–800℃: it can break the chain, reduce weight, reduce heavy tar, and inhibit carbon deposition.

[0015] The post-processor includes a cyclone dust collector and a quench cooler. The outlet of the pyrolyzer is connected to the inlet of the cyclone dust collector, and the outlet of the cyclone dust collector is connected to the inlet of the quench cooler.

[0016] The post-processor can remove dust, cool down and purify the combustible gas after catalytic cracking.

[0017] In one specific embodiment of the present invention, the cooling dust collector includes a dust collector and a cooling return tube. A filter screen is inclinedly arranged inside the dust collector. The inlet of the dust collector is inclined at the same angle as the filter screen. One end of the cooling return tube is connected to the outlet of the dust collector, and the other end is connected to the inlet of the water vapor mixer.

[0018] Furthermore, the outlet of the calciner is connected to the inlet of the side wall of the water-steam mixer via an outlet pipe, and an electrically controlled valve is installed on the outlet pipe.

[0019] In one specific embodiment of the present invention, the main catalytic bed and the backup catalytic bed are filled with catalyst, heating plates are attached to the side walls, and exhaust gas outlets are provided on the top side walls.

[0020] In one specific embodiment of the present invention, a filter screen is inclinedly arranged inside the dust collector, a dust collection groove is provided on one side of the bottom end of the filter screen, and a heating layer is provided on the bottom side of the dust collector.

[0021] Furthermore, a chuck is fixedly installed inside the pyrolyzer, and multiple catalytic cracking tubes and heating tubes are inserted at intervals on the chuck. The catalytic cracking tubes have a hollow structure with a perforated grid on their bottom side, and are filled with catalyst.

[0022] Implementing this invention has the following beneficial effects:

[0023] This biomass pyrolysis combustible gas steam catalytic detarting equipment is simple to assemble, the processes of each component are easy to control, the catalyst in the catalytic bed is easy to regenerate, and the combustible gas is dusted intermittently to prevent equipment blockage and corrosion. It is especially suitable for small-scale enterprise projects. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of the steam catalytic tar removal equipment for biomass pyrolysis combustible gas provided by the present invention;

[0026] In the diagram: 1. Pre-processor; 2. Dust collector; 3. Cooling tube; 4. Filter screen; 5. Air inlet; 6. Water-vapor mixer; 7. Calciner; 8. Processing pipeline; 9. Electrically controlled valve; 10. Catalytic bed; 11. Inlet layer; 12. Main catalytic bed; 13. Backup catalytic bed; 14. Outlet layer; 15. Inlet valve; 16. Outlet valve; 17. Heating plate; 18. Catalyst; 19. Waste gas outlet; 20. Filter dust collector; 21. Cracker; 22. Return pipe; 23. Ash collection trough; 24. Heating layer; 25. Chuck; 26. Catalytic cracking tube; 27. Heating tube; 28. Cyclone dust collector; and 29. Quencher. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figure 1 , Figure 1 A schematic diagram of the steam catalytic detarring device for biomass pyrolysis combustible gas provided by the present invention. This steam catalytic detarring device for biomass pyrolysis combustible gas includes:

[0029] The preprocessor 1 includes a cooling dust collector, a calciner 7, and a water-gas mixer 6. The cooling dust collector includes a dust collector 2 and a cooling return tube 3. A filter screen 4 is inclinedly installed inside the dust collector 2. The inlet 5 of the dust collector 2 has the same inclination as the filter screen 4. One end of the cooling return tube 3 is connected to the outlet of the dust collector 2, and the other end is connected to the inlet of the water-gas mixer 6 through a processing pipe 8. The outlet of the calciner 7 is connected to the inlet of the water-gas mixer 6 through another processing pipe 8. Each processing pipe 8 is equipped with an electrically controlled valve 9.

[0030] The preprocessor 1 can initially remove dust and cool down the coke-containing combustible gas; in the calciner 7, water is heated and calcined into superheated steam at 800℃, with a water-to-gas ratio of 1:1, and premixed with the gas.

[0031] The catalytic bed 10, from bottom to top, includes an inlet layer 11, a main catalytic bed 12 and a backup catalytic bed 13 arranged side by side, and an outlet layer 14. The outlet of the water-gas mixer 6 is connected to the inlet of the inlet layer 11. The two outlets of the inlet layer 11 are connected to the inlets of the main catalytic bed 12 and the backup catalytic bed 13, respectively. Both the main catalytic bed 12 and the backup catalytic bed 13 are equipped with inlet valves 15 and outlet valves 16. The outlets of the main catalytic bed 12 and the backup catalytic bed 13 are connected to the outlet layer 14. To facilitate catalyst regeneration and rest, this application provides two catalytic beds. The main catalytic bed 12 and the backup catalytic bed 13 are filled with catalyst 18, and heating plates 17 are attached to the side walls of both. Each has an exhaust gas outlet 19 on its top side wall.

[0032] Under the action of the catalyst (Ni / Al2O3, dolomite, noble metals, etc.) on the surface of the catalyst in the catalyst bed, tar macromolecules, H2O and hydrocarbons are adsorbed onto the active sites of the catalyst, and then H2O dissociates into ·H and ·OH active free radicals, and the C–C and C–H bonds of tar are weakened and activated.

[0033] The catalytic cracking reactor includes a filter dust collector 20 and a cracker 21. The outlet of the gas outlet layer 14 is connected to the inlet of the filter dust collector 20, and the outlet of the filter dust collector 20 is connected to the inlet of the cracker 21. The reflux port on the bottom side of the cracker 21 is connected to the top inlet of the water-gas mixer 6 through a reflux pipe 22. An electrically controlled valve is installed on the reflux pipe 22.

[0034] Specifically, a filter screen is inclinedly arranged inside the dust collector 20, and a dust collection trough 23 is provided on one side of the bottom end of the filter screen. A heating layer 24 is provided on the bottom side of the dust collector 20. A chuck 25 is fixedly installed inside the pyrolyzer 21. Multiple catalytic cracking tubes 26 and heating tubes 27 are inserted at intervals on the chuck 25. The catalytic cracking tubes 26 have a hollow structure, and a perforated grid is provided on their bottom side. The tubes are filled with catalyst.

[0035] The filter dust collector 20 in the catalytic cracking reactor first removes dust from the combustible gas coming out of the catalytic bed 10, and then enters the cracker 21 to carry out the catalytic cracking reaction. The catalytic cracking reaction is: large molecule tar → small molecule hydrocarbons, olefins, aromatics, coke; conditions: 700–800℃: it can break the chain, reduce weight, reduce heavy tar, and inhibit carbon deposition.

[0036] The post-processor includes a cyclone dust collector 28 and a quench cooler 29. The outlet of the pyrolysis unit 21 is connected to the inlet of the cyclone dust collector 28, and the outlet of the cyclone dust collector 28 is connected to the inlet of the quench cooler 29. The post-processor can remove dust, cool down, and purify the combustible gas after catalytic cracking.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A steam catalytic detarting device for biomass pyrolysis combustible gas, characterized in that, include: The preprocessor includes a cooling dust collector, a calciner, and a water-vapor mixer. The outlet of the cooling dust collector and the outlet of the calciner are respectively connected to the two inlets of the water-vapor mixer through processing pipes. Each processing pipe is equipped with an electrically controlled valve. The catalytic bed, from bottom to top, includes an inlet layer, a main catalytic bed and a backup catalytic bed arranged side by side, and an outlet layer. The outlet of the water-vapor mixer is connected to the inlet of the inlet layer. The two outlets of the inlet layer are respectively connected to the inlets of the main catalytic bed and the backup catalytic bed. The inlet and outlet of the main catalytic bed and the backup catalytic bed are each equipped with an inlet valve and an outlet valve. The outlets of the main catalytic bed and the backup catalytic bed are connected to the outlet layer. A catalytic cracking reactor includes a filter dust collector and a cracker. The outlet of the gas outlet layer is connected to the inlet of the filter dust collector, and the outlet of the filter dust collector is connected to the inlet of the cracker. The reflux port on the bottom side of the cracker is connected to the top inlet of the water-gas mixer through a reflux pipe. An electrically controlled valve is installed on the reflux pipe. The post-processor includes a cyclone dust collector and a quench cooler, wherein the outlet of the pyrolyzer is connected to the inlet of the cyclone dust collector, and the outlet of the cyclone dust collector is connected to the inlet of the quench cooler.

2. The steam catalytic detarting equipment for biomass pyrolysis combustible gas according to claim 1, characterized in that, The cooling dust collector includes a dust collector and a cooling return tube. A filter screen is installed at an inclination inside the dust collector. The inlet of the dust collector is at the same inclination as the filter screen. One end of the cooling return tube is connected to the outlet of the dust collector, and the other end is connected to the inlet of the water-vapor mixer.

3. The steam catalytic detarting equipment for biomass pyrolysis combustible gas according to claim 2, characterized in that, The outlet of the calciner is connected to the inlet of the side wall of the water-steam mixer via an outlet pipe, and an electrically controlled valve is installed on the outlet pipe.

4. The steam catalytic detarting equipment for biomass pyrolysis combustible gas according to claim 1, characterized in that, The main catalytic bed and the backup catalytic bed are filled with catalyst, heating plates are attached to the side walls, and exhaust gas outlets are provided on the top side walls.

5. The steam catalytic detarting equipment for biomass pyrolysis combustible gas according to claim 1, characterized in that, The filter dust collector is equipped with an inclined filter screen, and a dust collection trough is provided on one side of the bottom end of the filter screen. A heating layer is provided on the bottom side of the filter dust collector.

6. The steam catalytic detarting equipment for biomass pyrolysis combustible gas according to claim 5, characterized in that, The pyrolyzer is fixedly equipped with a chuck, on which multiple catalytic pyrolysis tubes and heating tubes are inserted at intervals. The catalytic pyrolysis tubes are hollow structures with a perforated grid on their bottom side, and are filled with catalyst.

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