Biomass gasification system with trough type fused salt photo-thermal assisted heat supply

Abstract

The utility model relates to the technical field of fused salt heat exchange, in particular to a biomass gasification system for trough type fused salt photo-thermal assisted heat supply. The utility model provides a biomass gasification system for trough type fused salt photo-thermal assisted heat supply. The biomass gasification system comprises a trough type fused salt heat collection system, a high-temperature fused salt storage tank, a biomass gasification furnace, a low-temperature fused salt storage tank, a gasified gas cooling tower, a combustible gas burner and a biomass feeding device, according to the utility model, energy is supplied to the first-stage heating of the material of the biomass gasifier body through groove-type molten salt heat exchange, so that the dependence on the biomass raw material as a fuel can be effectively reduced, and the gasification efficiency and the quality of a gasified product are improved; gasified gas of the gasification furnace reforms impurity gas and combusts the impurity gas to supply energy to the second stage of the gasification furnace, and the coupling mode is also beneficial to improving the heat energy utilization efficiency of the groove type photo-thermal system.

Description

Technical Field

[0001] The utility model relates to the technical field of molten salt heat exchange, in particular to a biomass gasification system assisted by trough molten salt solar thermal energy for heating. Background Art

[0002] As an important form of solar thermal utilization, the trough solar thermal power generation system (CSP-Parabolic Trough) focuses sunlight onto the heat collection pipe located at the focal line through a mirror array (i.e., a parabolic concentrator). The working medium (such as molten salt or heat transfer oil) in the heat collection pipe absorbs and stores solar energy and converts it into heat energy. However, due to the thermal stability limitation of the working medium under current technical conditions, its maximum working temperature generally remains around 500°C, which is relatively low compared to the requirements of some high-efficiency heat conversion processes. When applied to power generation or energy storage, the low heat exchange efficiency limits the improvement of steam parameters, thereby affecting the power generation efficiency and economy of the entire system.

[0003] Biomass gasification is a process of converting biomass raw materials (such as crop residues, forestry waste, municipal solid waste, etc.) into combustible gas (syngas, mainly composed of carbon monoxide, hydrogen, methane, etc.) under high temperature and anaerobic or limited oxygen conditions. This technology not only realizes the efficient utilization of biomass but also promotes the diversified utilization of renewable energy. The rich chemical components in syngas make it an ideal raw material for preparing high-value-added chemicals (such as methanol, ammonia, Fischer-Tropsch synthetic fuels, etc.). However, the biomass gasification process usually requires a relatively high initial temperature and a stable heat source to maintain the gasification reaction, which often relies on the partial combustion of the biomass raw material itself to provide, not only reducing the gasification efficiency but also increasing the consumption of raw materials and carbon emissions.

[0004] In view of the fact that a large amount of low-grade heat energy generated by the trough solar thermal system has not been fully utilized, while the biomass gasification process urgently needs a clean heat source. How to couple the trough solar thermal with biomass gasification, use the low-grade heat energy of the trough solar thermal for the primary heat exchange of biomass gasification, realize the coupling of the trough solar thermal and the biomass gasification system, and reduce the consumption of the biomass raw material itself during the biomass gasification process is an urgent problem to be solved. Summary of the Utility Model

[0005] To solve the problems existing in the prior art, the utility model provides a biomass gasification system assisted by trough molten salt solar thermal energy for heating, realizing the coupling of the trough solar thermal and the biomass gasification system and reducing the consumption of the biomass raw material itself during the biomass gasification process.

[0006] To achieve the above purpose, the utility model provides the following technical solutions:

[0007] The utility model provides a biomass gasification system assisted by trough molten salt solar thermal heating, which includes a trough molten salt heat collection system, a high-temperature molten salt storage tank, a biomass gasifier, a low-temperature molten salt storage tank, a gasification gas cooling tower, a combustible gas burner, and a biomass feeding device;

[0008] The trough molten salt heat collection system is used to heat molten salt and transport the heated high-temperature molten salt to the high-temperature molten salt storage tank; the high-temperature molten salt storage tank transports the high-temperature molten salt to the biomass gasifier; the biomass in the biomass gasifier exchanges heat indirectly with the high-temperature molten salt, and the high-temperature molten salt exchanges heat and cools down to form low-temperature molten salt, which is transported to the low-temperature molten salt storage tank and then to the trough molten salt heat collection system; the synthesis gas generated by the gasification of biomass in the biomass gasifier is transported to the gasification cooling tower; the small-molecule combustible gas separated after being cooled by the gasification cooling tower is transported to the combustible gas burner; a part of the high-temperature flue gas generated by the combustion of the combustible gas burner enters the gasification cooling tower, and the cooled flue gas is transported to the biomass feeding device and then to the biomass gasifier; the other part of the high-temperature flue gas is transported to the biomass gasifier.

[0009] Preferably, the trough molten salt heat collection system includes a plurality of trough concentrating units for heating molten salt.

[0010] Preferably, the trough molten salt heat collection system includes a high-temperature molten salt collecting port and a low-temperature molten salt dispersing port, the high-temperature molten salt collecting port is connected to the high-temperature molten salt storage tank; the low-temperature molten salt dispersing port is respectively connected to the trough concentrating unit and the low-temperature molten salt storage tank.

[0011] Preferably, the biomass gasifier includes a high-temperature molten salt inlet connected to the high-temperature molten salt storage tank.

[0012] Preferably, the biomass gasifier includes a molten salt heat exchange coil connected to the high-temperature molten salt inlet.

[0013] Preferably, the biomass gasifier includes a low-temperature molten salt outlet respectively connected to the low-temperature molten salt storage tank and the molten salt heat exchange coil.

[0014] Preferably, the biomass gasifier further includes a synthesis gas outlet connected to the gasification cooling tower.

[0015] Preferably, the biomass gasifier further includes a first high-temperature flue gas inlet connected to the combustible gas burner.

[0016] Preferably, the gasification cooling tower includes a synthesis gas inlet and a condensed combustible gas outlet; the synthesis gas inlet is connected to the gasification cooling tower; the condensed combustible gas outlet is connected to the combustible gas burner.

[0017] Preferably, the gasification cooling tower includes a second inlet for high-temperature flue gas and an outlet for low-temperature flue gas; the second inlet for high-temperature flue gas is connected to the combustible gas burner; and the outlet for low-temperature flue gas is connected to the biomass feeding device.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] The utility model converts solar energy into heat energy through a trough-type molten salt heat collection system and stores it in the molten salt, providing energy for the first-stage heating of the materials in the biomass gasification furnace body, which can effectively reduce the dependence on biomass raw materials as fuels themselves, improve the gasification efficiency and the quality of gasification products; the impurities in the reformed gas of the gasification gas in the gasification furnace are burned to provide energy for the second stage of the gasification furnace. This coupling method also helps to improve the heat energy utilization efficiency of the trough-type solar thermal system, broaden its application fields, realize the complementary utilization of solar energy and biomass energy, and is of great significance for promoting the sustainable development of renewable energy. Moreover, it can supply energy in stages according to the reaction temperature requirements of the gasification furnace body, the heat quality grades of solar thermal molten salt and high-temperature flue gas, etc., with a wide range of applications; the high-temperature gasification gas generated during the gasification process is cooled and purified in the cooling tower to remove impurities such as dust and tar, and at the same time, part of the heat energy is recovered, improving the quality of the gasification gas and reducing the energy consumption and pollution in the subsequent treatment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure of the utility model in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only schematic and are used to assist in understanding the utility model, rather than specifically defining the shapes and proportional dimensions of the components of the utility model.

[0021] In the drawings:

[0022] Figure 1 is a schematic structural diagram of the biomass gasification system assisted by trough-type molten salt solar thermal energy for heat supply according to the utility model;

[0023] Figure 2 is a schematic structural diagram of the gasification gas cooling tower according to the utility model;

[0024] In the figure, 1 is a trough-type molten salt heat collection system; 101 is a trough-type concentrating unit; 102 is a high-temperature molten salt collection port; 103 is a low-temperature molten salt dispersion port; 2 is a high-temperature molten salt storage tank; 3 is a biomass gasifier; 301 is a high-temperature molten salt inlet; 302 is a molten salt heat exchange coil; 303 is a low-temperature molten salt outlet; 304 is a first high-temperature flue gas inlet; 305 is a syngas outlet; 306 is a gasifying agent inlet; 307 is a slag discharge port for carbon slag; 4 is a low-temperature molten salt storage tank; 5 is a syngas cooling tower; 501 is a syngas inlet; 502 is a condensed combustible gas outlet; 503 is an oil product outlet; 504 is a second high-temperature flue gas inlet; 505 is a low-temperature flue gas outlet; 6 is a combustible gas burner; 7 is a biomass feeding device. Specific embodiments

[0025] In order to enable those skilled in the art to better understand the technical solutions in this utility model, the following will clearly and completely describe the technical solutions in the embodiments of this utility model with reference to the accompanying drawings in the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, rather than all of the embodiments. Based on the embodiments in this utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this utility model.

[0026] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiments.

[0027] Such as Figure 1As shown in the figure, the utility model provides a biomass gasification system assisted by trough molten salt solar thermal heating, which includes a trough molten salt heat collection system 1. The trough molten salt heat collection system 1 utilizes the focusing effect of sunlight to concentrate sunlight on the heat collection pipe through a trough reflector, heating the molten salt in the pipe. The molten salt, as a heat transfer medium, can store and transfer a large amount of heat energy, convert solar energy into heat energy, and store it in the molten salt to provide heat source for the subsequent biomass gasification process; a high-temperature molten salt storage tank 2, which can store the high-temperature molten salt transported from the trough molten salt heat collection system 1 and serve as a heat source supply station for the biomass gasifier, has an efficient heat insulation layer to reduce heat loss, and is equipped with a molten salt pump to maintain the circulation of the molten salt; a biomass gasifier 3, which can convert biomass raw materials into combustible gas through chemical reactions such as pyrolysis and gasification at high temperature. The high-temperature molten salt exchanges heat indirectly with the biomass through a heat exchange device to provide the heat required for gasification, and can achieve the efficient conversion of biomass to generate syngas that can be used for power generation, heating or chemical raw materials; a low-temperature molten salt storage tank 4, which can store the low-temperature molten salt cooled after heat exchange with the biomass gasifier 3 and is ready to be sent back to the trough molten salt heat collection system 1 for heating again. It also has an efficient heat insulation layer to reduce heat loss and is equipped with a molten salt circulation pump, which can realize the recycling of the molten salt and improve the energy utilization efficiency of the whole system; a gasification gas cooling tower 5, which cools and purifies the syngas coming out of the biomass gasifier 3 to separate small molecule combustible gas; a combustible gas burner 6 burns the small molecule combustible gas separated by the gasification cooling tower 5 to generate high-temperature flue gas. Using the heat energy of the high-temperature flue gas, part of it is used for reheating the gasification cooling tower 5, and the other part returns to the biomass gasifier 3 to improve the gasification efficiency; a biomass feeding device 7, which feeds the biomass raw materials into the biomass gasifier 3 for gasification reaction to ensure the continuous and stable supply of biomass raw materials and maintain the normal operation of the gasifier.

[0028] The trough - type molten salt heat - collecting system 1 is connected to the high - temperature molten salt storage tank 2; the trough - type molten salt heat - collecting system 1 is used to heat the molten salt and transport the heated high - temperature molten salt to the high - temperature molten salt storage tank 2; the high - temperature molten salt storage tank 2 is connected to the biomass gasifier 3; the high - temperature molten salt storage tank 2 transports the high - temperature molten salt to the biomass gasifier 3; the biomass gasifier 3 is respectively connected to the low - temperature molten salt storage tank 4 and the gasification cooling tower 5; the low - temperature molten salt storage tank 4 is connected to the trough - type molten salt heat - collecting system 1; the biomass in the biomass gasifier 3 exchanges heat indirectly with the high - temperature molten salt, and the high - temperature molten salt cools down after heat exchange to form low - temperature molten salt, which is transported to the low - temperature molten salt storage tank 4 and then to the trough - type molten salt heat - collecting system 1; the synthesis gas generated by the gasification of biomass in the biomass gasifier 3 is transported to the gasification cooling tower 5; the gasification cooling tower 5 is respectively connected to the combustible gas burner 6 and the biomass feeding device 7; the combustible gas burner 6 is connected to the biomass feeding device 3; the biomass feeding device 7 is connected to the biomass gasifier 3; the small - molecule combustible gas separated after being cooled by the gasification cooling tower 5 is transported to the combustible gas burner 6; a part of the high - temperature flue gas generated by the combustion of the combustible gas burner 6 enters the gasification cooling tower 5, and the cooled flue gas is transported to the biomass feeding device 7 and then enters the biomass gasifier 3; another part of the high - temperature flue gas is transported to the biomass gasifier 3.

[0029] Among them, the trough - type molten salt heat - collecting system 1 includes a number of trough - type concentrating units 101, a high - temperature molten salt collecting port 102, and a low - temperature molten salt dispersing port 103; the biomass gasifier 3 includes a high - temperature molten salt inlet 301, a molten salt heat - exchange coil 302, a low - temperature molten salt outlet 303, a first high - temperature flue gas inlet 304, a synthesis gas outlet 305, a gasifying agent inlet 306, and a slag discharge port 307; as Figure 2 shown, the gasification cooling tower 5 includes a synthesis gas inlet 501, a condensed combustible gas outlet 502, an oil product outlet 503, a second high - temperature flue gas inlet 504, and a low - temperature flue gas outlet 505.

[0030] The trough - type concentrating units 101 are used to heat the molten salt; the heated high - temperature molten salt is collected through the high - temperature molten salt collecting port 102 and then pumped to the high - temperature molten salt storage tank 2, and then sent into the molten salt heat - exchange coil 302 through the high - temperature molten salt inlet 301 to exchange heat indirectly with the biomass in the biomass gasifier 3. After heat exchange and cooling, it is sent out from the low - temperature molten salt outlet 303 to the low - temperature molten salt storage tank 4, and then sent to each trough - type concentrating unit 101 through the low - temperature molten salt dispersing port 103.

[0031] The syngas generated from the gasification of biomass in the biomass gasifier 3 is sent to the gasification cooling tower 5 through the syngas outlet 305 and then through the syngas inlet 501; the small-molecule combustible gas separated after the syngas is cooled enters the combustible gas burner 6 through the condensed combustible gas outlet 502; the remaining components are cooled to liquid oil products and stored at the bottom of the gasification cooling tower 5. A part of the high-temperature flue gas generated by the combustion of the combustible gas burner 6 enters the cavity at the bottom of the gasification cooling tower 5 through the second high-temperature flue gas inlet 504 to heat and keep warm the liquid oil products, and then is further processed and upgraded for utilization. The cooled flue gas is sent out from the low-temperature flue gas outlet 505 to the biomass feeding device 7, and the preheated and cooled low-temperature flue gas is sent into the furnace through the gasifying agent inlet 306 at the bottom of the biomass gasifier 3 to fluidize the biomass raw materials. The char residue after the gasification reaction is discharged from the slag discharge port 307; another part enters the biomass gasifier 3 through the first high-temperature flue gas inlet 304.

[0032] The molten salt is heated by the trough-type molten salt heat collection system 1 and the temperature rises to 390 - 410 °C. The low-temperature molten salt after indirect heat exchange in the biomass gasifier 3 has a temperature of 320 - 330 °C; the reaction temperature in the biomass gasifier 3 is 550 - 750 °C; the cooling temperature of the gasification gas cooling tower 5 is 145 - 160 °C; the temperature of the liquid oil product after being heated by the high-temperature flue gas remains at 400 - 500 °C; the biomass gasifier 3 is a vertical fluidized bed; the small-molecule combustible gas mainly composed of CO, H2, CH4, CO2, etc. separated by condensation in the gasification cooling tower 5, and the condensed liquid oil product is stored at the bottom of the gasification cooling tower 5; the temperature of the high-temperature flue gas generated by the combustion of the combustible gas burner 6 is 750 - 850 °C.

[0033] The utility model converts solar energy into heat energy through the trough-type molten salt heat collection system 1 and stores it in the molten salt, providing a stable heat source for biomass gasification and realizing the full utilization of clean energy. The high-temperature molten salt provides a stable heat source for the biomass gasifier 3, promotes the rapid and complete gasification of biomass, improves the gasification efficiency and the quality of syngas; the low-temperature molten salt is reheated and recycled, reducing energy consumption and waste; at the same time, the high-temperature flue gas generated by the combustion of combustible gas is also used in the heating and gasification processes, improving the energy utilization efficiency of the overall system; the biomass gasification process reduces the pollutant emissions generated by the direct combustion of biomass; at the same time, the use of renewable energy such as solar energy and biomass energy reduces the dependence on fossil fuels and greenhouse gas emissions.

[0034] The utility model provides energy for the first-stage heating of the furnace body materials of the biomass gasifier 3 through trough-type molten salt heat exchange, which can effectively reduce the dependence on biomass raw materials as fuel itself, improve the gasification efficiency and the quality of gasification products; through the combustion of the reformed impurity gas of the gasification gas in the biomass gasifier 3 to provide energy for the second stage of the gasifier, this coupling method also helps to improve the heat energy utilization efficiency of the trough-type solar thermal system.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this utility model belongs. The terms used in the specification of this utility model herein are for the purpose of describing specific embodiments only and are not intended to limit this utility model. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

Claims

1. A biomass gasification system assisted by trough molten salt solar thermal heating, characterized in that, It includes a trough-type molten salt heat collection system (1), a high-temperature molten salt storage tank (2), a biomass gasifier (3), a low-temperature molten salt storage tank (4), a gasification gas cooling tower (5), a combustible gas burner (6), and a biomass feeding device (7); The trough-type molten salt heat collection system (1) is used to heat the molten salt and transport the heated high-temperature molten salt to the high-temperature molten salt storage tank (2); the high-temperature molten salt storage tank (2) transports the high-temperature molten salt to the biomass gasifier (3); the biomass in the biomass gasifier (3) exchanges heat indirectly with the high-temperature molten salt, and the high-temperature molten salt exchanges heat and cools down to form low-temperature molten salt, which is transported to the low-temperature molten salt storage tank (4) and then to the trough-type molten salt heat collection system (1); the synthesis gas generated by gasifying the biomass in the biomass gasifier (3) is transported to the gasification cooling tower (5); the small-molecule combustible gas separated after being cooled by the gasification cooling tower (5) is transported to the combustible gas burner (6); a part of the high-temperature flue gas generated by the combustion of the combustible gas burner (6) enters the gasification cooling tower (5), and the cooled flue gas is transported to the biomass feeding device (7) and then to the biomass gasifier (3); another part of the high-temperature flue gas is transported to the biomass gasifier (3).

2. The biomass gasification system assisted by trough molten salt solar thermal heating according to claim 1, wherein The trough-type molten salt heat collection system (1) includes a number of trough-type concentrating units (101), and the trough-type concentrating units (101) are used to heat the molten salt.

3. The biomass gasification system for trough molten salt solar thermal assisted heating according to claim 2, wherein The trough-type molten salt heat collection system (1) includes a high-temperature molten salt collecting port (102) and a low-temperature molten salt dispersing port (103), and the high-temperature molten salt collecting port (102) is connected to the high-temperature molten salt storage tank (2); the low-temperature molten salt dispersing port (103) is respectively connected to the trough-type concentrating units (101) and the low-temperature molten salt storage tank (4).

4. The biomass gasification system for trough molten salt solar thermal assisted heating according to claim 1, characterized in that, The biomass gasifier (3) includes a high-temperature molten salt inlet (301), and the high-temperature molten salt inlet (301) is connected to the high-temperature molten salt storage tank (2).

5. The biomass gasification system for trough molten salt solar thermal assisted heating according to claim 4, wherein The biomass gasifier (3) includes a molten salt heat exchange coil (302), and the molten salt heat exchange coil (302) is connected to the high-temperature molten salt inlet (301).

6. The biomass gasification system for trough molten salt solar thermal assisted heating according to claim 5, wherein The biomass gasifier (3) includes a low-temperature molten salt outlet (303), and the low-temperature molten salt outlet (303) is respectively connected to the low-temperature molten salt storage tank (4) and the molten salt heat exchange coil (302).

7. The biomass gasification system for trough molten salt solar thermal assisted heating according to claim 6, wherein The biomass gasifier (3) further includes a synthesis gas outlet (305); the synthesis gas outlet (305) is connected to the gasification cooling tower (5).

8. The biomass gasification system for trough molten salt solar thermal assisted heating according to claim 1, characterized in that, The biomass gasifier (3) further includes a first high-temperature flue gas inlet (304); the first high-temperature flue gas inlet (304) is connected to the combustible gas burner (6).

9. The biomass gasification system with trough molten salt solar thermal assisted heating according to claim 1, characterized in that The gasification cooling tower (5) includes a synthesis gas inlet (501) and a condensed combustible gas outlet (502); the synthesis gas inlet (501) is connected to the gasification cooling tower (5); the condensed combustible gas outlet (502) is connected to the combustible gas burner (6).

10. The biomass gasification system with trough molten salt solar thermal assisted heating according to claim 9, wherein, The gasification cooling tower (5) includes a second high-temperature flue gas inlet (504) and a low-temperature flue gas outlet (505); the second high-temperature flue gas inlet (504) is connected to the combustible gas burner (6); the low-temperature flue gas outlet (505) is connected to the biomass feeding device (7).

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