Device for preparing slurry organic desulfurization and denitrification agent through co-baking of biomass coupled CaO

Abstract

The utility model discloses a device for preparing a slurry organic desulfurization and denitrification agent through co-baking of biomass coupled with CaO. The device comprises a biomass bin, a CaO bin, a screw feeder, a double-paddle baking-crushing machine, an external combustor, a condenser, a wet ball mill, a urea aqueous solution tank, a dispersing agent tank and the like. Biomass and CaO are respectively fed into the double-blade baking-crushing machine through the screw feeder to be subjected to baking reaction; keeping the temperature of the baked material at the baking temperature, feeding the baked material into a condenser for quenching, mixing the quenched and baked biomass with the condensed baking liquid to form slurry, feeding the mixed slurry into a wet ball mill, and stirring and grinding the mixed slurry together with a urea aqueous solution and a dispersing agent to prepare biomass-based organic desulfurization and denitrification agent slurry. The desulfurization and denitrification agent provided by the utility model has double denitrification effects, namely a reburning denitrification effect of baked biomass powder and a deep reduction denitrification effect of urea under the catalytic activation effect of baking liquid, and is suitable for desulfurization and denitrification transformation of distributed small-sized industrial kilns.

Description

Technical Field

[0001] The utility model relates to the technical field of production of desulfurization and denitration agents, in particular to a device for preparing organic desulfurization and denitration agents from biomass. Background Art

[0002] NOx and SOx are one of the main air pollutants. Their large-scale emissions have caused serious environmental problems such as acid rain and photochemical smog. At the same time, the toxicity of these two substances has endangered the survival of humans and other organisms in the earth's ecosystem. Therefore, it is imperative to control the emission of combustion pollutants such as NOx and SOx. Due to site constraints or economic issues, it has always been difficult to transform the desulfurization and denitrification of small coal-fired industrial kilns. Therefore, the use of simple and effective desulfurization and denitrification agents in the high reaction temperature section is an effective solution for deep desulfurization and denitrification of small coal-fired industrial kilns.

[0003] In traditional desulfurization and denitrification technologies, ammonia water, urea, calcium-based desulfurizers, etc. are mainly used as desulfurization and denitrification agents. Traditional desulfurization and denitrification agents not only have low desulfurization and denitrification efficiency, but are also accompanied by secondary pollution problems such as ammonia escape, and the presence of amino products poses certain hidden dangers to the safety of the site. Biomass is an organic matter produced by plants through photosynthesis. It has huge reserves, is widely distributed, is renewable, and is an environmentally friendly low-carbon energy source. Biomass and its derivatives can not only be used as energy, but also can be prepared as industrial products or chemical products, with broad development prospects. The organic desulfurization and denitrification agent prepared using abundant biomass resources can remove SOx and NOx at the same time. It not only has high desulfurization and denitrification efficiency, but also avoids the problems caused by secondary pollution. It is a clean and efficient desulfurization and denitrification agent. The patent [Preparation method and application of efficient desulfurization and denitrification agent for coal-fired boilers (CN201410417940.0)] proposes biomass pyrolysis bio-oil as an additive for desulfurization and denitrification components, mainly using the organic acid in the biomass pyrolysis oil to react with the calcium base to generate organic acid calcium salts with desulfurization and denitrification effects. However, the pyrolysis bio-oil contains a large amount of water, which can easily cause the reaction temperature to drop when it is sprayed into the furnace or high-temperature flue gas as a desulfurization and denitrification agent, affecting the combustion conditions; at the same time, the solid product of biomass pyrolysis, pyrolysis coke, has a porous carbon-based skeleton structure, which can play a key role in improving the reaction interface during the desulfurization and denitrification process. Therefore, this patent proposes a method and device for synthesizing a slurry organic desulfurization and denitrification agent by co-baking biomass raw materials and CaO. Utility Model Content

[0004] Purpose of the utility model: In view of the above-mentioned prior art, a device for preparing slurry organic desulfurization and denitrification agent by co-baking biomass coupled with CaO is proposed. Biomass raw materials are co-baked and crushed with CaO to make a slurry-like organic desulfurization and denitrification agent with simultaneous desulfurization and denitrification effects. The slurry-like organic desulfurization and denitrification agent is an environmentally friendly and safe organic desulfurization and denitrification agent with broad application prospects in the field of small industrial kilns.

[0005] Technical solution:

[0006] The utility model shows a device for preparing slurry organic desulfurization and denitrification agent by co-baking biomass coupled with CaO, comprising: a biomass silo, a CaO silo, a screw feeder, a double-blade baking-crusher, an external burner, a condenser, a wet ball mill, a urea aqueous solution tank, a dispersant tank, a pump, and a paddle box;

[0007] The outlet of the biomass silo is connected to the screw feeder, which is connected to the material inlet of the double-blade baking-crusher. The outlet of the CaO silo is connected to the screw feeder, which is connected to the material inlet of the double-blade baking-crusher. The discharge port of the double-blade baking-crusher is connected to the inlet of the condenser, which is connected to the feed port of the wet ball mill. The non-condensable volatile matter outlet of the condenser is connected to the inlet of the external burner, which is equipped with an auxiliary fuel inlet. The high-temperature flue gas outlet of the external burner is connected to the hot flue gas inlet of the double-blade baking-crusher, and the hot flue gas of the double-blade baking-crusher is discharged through the outlet after heat exchange. Cold water is fed into the cooling medium inlet of the condenser and discharged through the cooling medium outlet of the condenser after absorbing heat. The urea aqueous solution tank is connected to the pump, which is connected to the urea aqueous solution addition inlet of the wet ball mill. The dispersant tank is connected to the pump, which is connected to the dispersant addition inlet of the wet ball mill. The slurry discharge port of the wet ball mill is connected to the slurry box.

[0008] Compared with the traditional organic desulfurization and denitrification agent preparation device, the utility model has the following innovative features and expected beneficial effects:

[0009] (1) The organic desulfurization and denitrification agent is prepared by using biomass carbon neutralization raw materials. CaO not only plays a role in catalyzing the baking process and improving the grindability during the preparation process, but also reacts with acetic acid in the baking liquid to form active calcium acetate, which is an effective desulfurization component;

[0010] (2) Taking advantage of the fact that the torrefaction process improves the grindability of biomass, the torrefaction and crushing are coupled in a double-blade torrefaction-crusher, and the torrefaction solid phase and liquid phase are rapidly cooled together in a condenser to obtain a preliminary slurry. The torrefied biomass powder and torrefaction liquid both play a key role in the denitrification process. When the torrefied biomass powder is sprayed into the desulfurization and denitrification reaction zone (600-900°C) of an industrial kiln, a decomposition reaction occurs to form a reducing atmosphere, which has a good reduction and denitration effect on NOx (similar to the principle of fuel reburning denitrification). At the same time, a thermal decomposition product with a porous carbon-based skeleton structure is produced, which can adsorb gas phase reaction components, enhance the reaction interface, increase the reaction time, and improve the desulfurization and denitrification effect. When the torrefaction liquid is sprayed into the desulfurization and denitrification reaction zone, it can induce the formation of a large number of active free radicals, activating NOx to undergo a reduction reaction with urea components;

[0011] (3) The desulfurization and denitrification agent proposed in the utility model has a dual denitrification effect, one is the reburning and denitrification effect of the roasted biomass powder, and the other is the further deep reduction and denitrification of urea under the catalytic activation of the active free radicals in the roasting liquid. The denitrification effect is high, and the installation does not require the modification of the original equipment. Only a spray gun atomization is required in the reaction temperature zone. It is suitable for the desulfurization and denitrification modification of decentralized small industrial kilns;

[0012] (4) The desulfurization and denitrification agent preparation device proposed in the utility model has the characteristics of energy self-sufficiency and no pollution, and the raw material price is cheap, and there is no external emission in the entire production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attached Figure 1 This is a structural diagram of a device for preparing a slurry organic desulfurization and denitrification agent by co-baking biomass coupled with CaO as described in the utility model:

[0014] In the figure: 1-biomass silo, 2-screw feeder, 3-CaO silo, 4-screw feeder, 5-double-blade baking-crusher, 6-external burner, 7-condenser, 8-wet ball mill, 9-urea aqueous solution tank, 10-pump, 11-dispersant tank, 12-pump, 13-slurry tank.

[0015] The present invention will be further explained below in conjunction with the accompanying drawings.

[0016] like Figure 1 As shown, the device for preparing slurry organic desulfurization and denitrification agent by co-baking biomass coupled with CaO in the utility model comprises: a biomass silo 1, a CaO silo 3, a screw feeder 2 and a screw feeder 4, a double-blade baking-crusher 5, an external burner 6, a condenser 7, a wet ball mill 8, a urea aqueous solution tank 9, a dispersant tank 11, pumps 10 and 12, and a slurry tank 13;

[0017] The outlet of the biomass silo 1 is connected to the screw feeder 2, the outlet of the CaO silo 3 is connected to the screw feeder 4, the outlet 14 of the screw feeder 2 and the outlet 15 of the screw feeder 4 are connected to the material inlet 17 of the double-blade roasting-crushing machine 5, the discharge port 19 of the double-blade roasting-crushing machine 5 is connected to the inlet 23 of the condenser 7, and the discharge port 27 of the condenser 7 is connected to the feed port 28 of the wet ball mill 8; the non-condensable volatile matter outlet 24 of the condenser 7 is connected to the inlet 22 of the external burner 6, and the external burner 6 is equipped with an auxiliary fuel inlet Port 21, the high-temperature flue gas outlet 20 of the external burner 6 is connected to the hot flue gas inlet 18 of the external double-blade baking-crusher 5, and the hot flue gas in the double-blade baking-crusher 5 is discharged through the outlet 16 after heat exchange; cold water is fed into the cooling medium inlet 25 of the condenser 7, and is discharged through the cooling medium outlet 26 of the condenser 7 after absorbing heat; the urea aqueous solution tank 9 is connected to the pump 10, the dispersant tank 11 is connected to the pump 12, and the pump 10 and the pump 12 are connected to the addition inlet 29 of the wet ball mill 8; the slurry discharge port 30 of the wet ball mill 8 is connected to the slurry tank 13.

[0018] Based on the above-mentioned device for preparing slurry organic desulfurization and denitrification agent by co-baking of biomass coupled with CaO, the specific steps are: biomass raw materials and CaO are fed from biomass silo 1 and CaO silo 3 into double-blade baking-crusher 5 through screw feeder 2 and screw feeder 4, CaO and biomass raw materials undergo baking reaction in baking-crusher 5, and the reaction temperature is (250-350℃), which is essentially a low-temperature pyrolysis, and under the catalytic action of CaO, the biomass raw materials undergo mild deoxygenation and dehydration, thereby increasing the energy density of the biomass raw materials; and baking improves the crushing efficiency of the biomass. The roasted biomass is initially crushed under the action of the double-blade stirring; the roasted materials (biomass and CaO) are kept warm at the roasting temperature and fed into the condenser 7 for rapid cooling, and the rapidly cooled roasted biomass is mixed with the condensed roasting liquid to form a slurry; the solid-liquid mixed slurry produced by the condenser 7 is fed into the wet ball mill 8, and at the same time, the urea aqueous solution tank 9 and the dispersant tank 11 are fed into the wet ball mill 8 through pumps 10 and 12, and the urea aqueous solution (urea concentration 1%-10%) and the dispersant (dispersant concentration 0.1%-1%) are stirred and ground together to prepare a biomass-based organic desulfurization and denitrification agent slurry.

[0019] Among them, the non-condensable volatiles generated in the condenser 7 are fed into the external burner 6 through the gas outlet, and burn under the action of the auxiliary fuel to produce high-temperature flue gas, and the high-temperature flue gas is fed into the double-blade baking-crushing machine 5 to provide heat for the baking reaction; the cold source of the condenser 7 is natural cold water, and the temperature is room temperature. After heat exchange, the hot water is discharged.

[0020] The utility model discloses a device for preparing a slurry organic desulfurization and denitrification agent by co-baking biomass-coupled CaO, the purpose of which is to prepare an environmentally friendly and pollution-free organic desulfurization and denitrification agent based on biomass raw materials, which mainly contains five components: first, calcium acetate, which is generated by the reaction between CaO and acetic acid generated in the baking process, and is an active desulfurization component with good efficacy; second, a baked biomass powder component, which undergoes a decomposition reaction to form a reducing atmosphere when sprayed into the desulfurization and denitrification reaction range (600-900°C) of an industrial kiln, and has a good reducing and denitrifying effect on NOx; at the same time, the baked biomass powder component can be pyrolyzed in the temperature range of 600-900°C to produce a porous carbon-based skeleton structure. The first is thermal decoking, which can adsorb gas-phase reaction components, enhance the reaction interface, increase the reaction time, and improve the desulfurization and denitrification effects; the second is baking liquid, which comes from the condensable components produced in the baking process, and is composed of active small molecule groups such as acids, ketones, aldehydes, and furans. When sprayed into the desulfurization and denitrification reaction zone, it can induce the formation of a large number of active free radicals, activate NOx and urea components to undergo reduction reactions to form N2; the third is urea, which comes from the urea aqueous solution added during wet ball milling, and it mainly acts as a reducing agent in the desulfurization and denitrification process; the fifth is dispersant, whose main function is to prevent the solid phase of the desulfurization and denitrification blades from agglomerating, so that they can be better dispersed in the liquid to form a slurry with good fluidity. In addition, the present invention uses biomass carbon neutral raw materials to prepare organic desulfurization and denitrification agents. CaO not only catalyzes the baking process and improves grindability during the preparation process, but also reacts with acetic acid in the baking liquid to form active calcium acetate, which is an effective desulfurization component. The baking process improves the grindability of biomass, and the baking and crushing are coupled in a double-blade baking-crusher. The baked solid and liquid substances are rapidly cooled in the condenser to obtain a preliminary slurry. The baked biomass powder and the baking liquid both play a key role in the denitrification process. When the baked biomass powder is sprayed into the desulfurization and denitrification reaction range (600-900°C) of the industrial kiln, a decomposition reaction occurs to form a reducing atmosphere, which has a good reduction and denitrification effect on NOx (similar to the principle of fuel reburning denitrification), and can be thermally The decomposition produces thermal decomposition coke with a porous carbon-based skeleton structure, which increases the reaction interface and promotes the effect of desulfurization and denitrification reactions. When the baking liquid is sprayed into the desulfurization and denitrification reaction zone, it can induce the formation of a large number of active free radicals, activate NOx and urea components for reduction reaction; the desulfurization and denitrification agent proposed by the utility model has a dual denitrification effect, one is the reburning and denitrification effect of the baked biomass powder, and the other is the further deep reduction and denitrification of urea under the catalytic activation of the active free radicals of the baking liquid. The denitrification effect is high, and the installation does not require the modification of the original equipment. Only a spray gun atomization is required in the reaction temperature zone. It is suitable for the desulfurization and denitrification modification of decentralized small-scale industrial kilns; the desulfurization and denitrification agent preparation device proposed by the utility model has the characteristics of energy self-sufficiency and pollution-free, and the raw material price is cheap, and the entire production process has no external emissions.

[0021] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should be regarded as within the protection scope of the present invention.

Claims

1. A device for preparing slurry organic desulfurization and denitrification agent by co-baking biomass coupled with CaO, characterized in that: It includes biomass silo, screw feeder, CaO silo, screw feeder, double-blade roaster-crusher, external burner, condenser, wet ball mill, urea aqueous solution tank, pump, dispersant tank and slurry tank; The outlet of the biomass silo is connected to the screw feeder, which is connected to the material inlet of the double-blade baking-crusher. The outlet of the CaO silo is connected to the screw feeder, which is connected to the material inlet of the double-blade baking-crusher. The discharge port of the double-blade baking-crusher is connected to the inlet of the condenser, which is connected to the feed port of the wet ball mill. The non-condensable volatile matter outlet of the condenser is connected to the inlet of the external burner, which is equipped with an auxiliary fuel inlet. The high-temperature flue gas outlet of the external burner is connected to the hot flue gas inlet of the double-blade baking-crusher, and the hot flue gas of the double-blade baking-crusher is discharged through the outlet after heat exchange. Cold water is fed into the cooling medium inlet of the condenser and discharged through the cooling medium outlet of the condenser after absorbing heat. The urea aqueous solution tank is connected to the pump, which is connected to the urea aqueous solution addition inlet of the wet ball mill. The dispersant tank is connected to the pump, which is connected to the dispersant addition inlet of the wet ball mill. The slurry discharge port of the wet ball mill is connected to the slurry box.

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