A system and method for producing a biomass-char based aquatic grass mud pellet

Abstract

The application discloses a biomass charcoal-based water grass mud particle production system and method, relates to the field of waste resource utilization and water grass mud production and preparation, and produces waste biomass and shield mud into biomass charcoal-based water grass mud particles through a pulverizer, a storage hopper, a mixing and granulating system, a drying system, a pyrolysis system, a combustion system, a waste heat utilization system, a cooling and discharging system, a screening and packaging system, a tail gas treatment system and an electrical automatic control system. The product is black particles, has the characteristics of long-term soaking, not easy to powder, not muddy, rich in nutrition, pollution reduction and carbon sequestration, can replace the water grass mud prepared by taking black soil as raw material for fish tank landscaping, has wide application prospect and market value, realizes high-value reuse of waste biomass and shield mud, and opens up a new road.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste biomass resource utilization, shield mud high-value utilization and high-quality water grass mud preparation, and particularly relates to a production system and method of biomass charcoal-based water grass mud particles. BACKGROUND

[0002] Waste biomass includes straw, garden pruning branches, waste bamboo materials, etc., and has problems such as large amount, wide range, and low resource utilization rate. As for straw, the current main disposal method is in-situ return to field technology and straw carbonization technology. After the straw is returned to the field, many pests and diseases and grass damage are bred in the decomposition process, which affects the normal germination of seeds, causes farming obstacles, and reduces crop yield. When straw carbonization is used, on the one hand, the high production cost of straw carbon limits its large-scale application in agriculture, and on the other hand, the high ash content of Si, Mg, Ca, K and other impurities in straw carbon cannot be used as raw materials for manufacturing high-quality activated carbon. Due to the problems of high cost and low quality of straw carbon, the market for straw carbon is extremely limited. Therefore, it is urgent to develop waste biomass resource utilization technology to improve the value of products.

[0003] With the rapid development of China's economy, subway, high-speed rail, highway and other infrastructure projects are developing rapidly. In the process of building infrastructure facilities (such as tunnels), shield machines are often used, which produce a large amount of shield mud. In order to facilitate transportation, reduce shield machine wear and tear, improve shield machine tunneling parameters and improve shield machine tunneling quality, surfactants and water need to be added, and these substances will mix into the shield mud. Once the shield mud containing surfactants enters the water, it will have adverse effects on aquatic organisms. In addition, it is difficult to dry the shield mud containing surfactants, and it has high fluidity, like a marsh. If it is directly landfilled or accumulated in large quantities, it may cause potential geological hazards. At present, the main utilization method of shield mud is to recover the finished sand inside through a sand washing machine, and the remaining shield mud is used for baking bricks. However, the quality of the bricks prepared from shield mud is not high, and the added value is low. Therefore, it is urgent to develop shield mud resource utilization technology to improve the value of shield mud products.

[0004] It can be seen that the current waste biomass and shield mud resource utilization processes all face the industry pain point problem of low product value and low market demand. In view of the above problems, high-value products are prepared by finding market demand, so as to realize the high-value utilization of waste biomass and shield mud.

[0005] Water grass mud is a material used for growing water grass or decorating aquariums, which has broad market demand. At present, the water grass mud on the market mainly includes black soil water grass mud, ceramic sand and red soil. The above-mentioned water grass muds have many problems, such as that the black soil resources cannot be taken at will, the ceramic sand is too hard and has no nutrient elements, and the red soil lacks nutrient elements and is yellow. In view of the above problems, the biomass charcoal-based water grass mud is prepared by using waste biomass and shield mud as raw materials through the synergistic pyrolysis technology. The product not only contains biomass charcoal, but also is rich in potassium, calcium, magnesium, nitrogen, phosphorus and other nutrient elements, has abundant pores, is not easy to powder after long-term soaking, is free of cleaning, and is black in color. It is a high-quality water grass mud product, which has the advantages of high product value and wide application market. The present application not only breaks through the technical bottleneck of high-value utilization of waste biomass and shield mud, but also has the effects of carbon sequestration and emission reduction, and has significant economic and ecological benefits. SUMMARY

[0006] The present application is based on the synergistic pyrolysis technology of waste biomass and shield mud, and provides a production system and method of biomass charcoal-based water grass mud particles, to solve the problem of difficult high-value utilization of waste biomass and shield mud.

[0007] A biomass charcoal-based water grass mud particle and its production process system, comprising the following steps: waste biomass crushing and storage, waste biomass and shield mud mixing and granulation, granular raw material drying and carbonization, cooling and screening, waste heat utilization and tail gas treatment, the devices and systems involved including: a crusher, a storage hopper, a mixing and granulation system, a drying system, a pyrolysis system, a combustion system, a waste heat utilization system, a cooling and discharging system, a screening system, a tail gas treatment system and an electrical automatic control system.

[0008] The waste biomass is straw, forestry waste biomass, livestock and poultry manure, etc. After being crushed by a crusher to a particle size of less than 2 mm, the waste biomass is stored in a storage hopper. The shield mud is a mud block produced during the construction process, which contains organic matter such as surfactants and flocculants, and has a water content of less than 90%. The shield mud is stored in another storage hopper.

[0009] The mixing and granulation system is provided with a material mixing and stirring device and a granulation device. By controlling the discharging rate of the storage hopper, the ratio of shield mud and biomass raw material can be controlled, wherein the biomass raw material accounts for 5-60%, and no adhesive needs to be added. The material mixing and stirring device can control the water content of the mixed material, and the granulation device can prepare spherical particles with a diameter of 1-20 mm. Through frequency regulation, continuous feeding and discharging can be realized. The well-granulated raw material particles are sent to a belt dryer by a belt conveyor.

[0010] The drying system is provided with a multi-layer belt dryer, a condenser, and the belt dryer is internally provided with a plurality of layers of 20-80 mesh stainless steel wire mesh, stainless steel support rods, material blocking plates, chains, transmission devices, and a moisture exhaust fan, and the heat energy utilization rate is improved by using the multi-layer closed countercurrent heat exchange technology and the water vapor heat pipe heat exchange technology. The drying tail gas is input into the condenser for water vapor separation after being input into the condenser by the moisture exhaust fan, the non-condensable gas is input into the combustion chamber through the heat exchanger for combustion, and the moisture content of the dried material is 5%-15%.

[0011] The pyrolysis carbonization system is provided with a rotary bed pyrolysis furnace and a cyclone dust collector, the pyrolysis furnace is internally provided with a radiation heating pipe, the oxygen-deficient condition in the furnace is ensured, the pyrolysis time is 1-2 h, the pyrolysis temperature is 350-800℃, the material particles are laid flat on the furnace bottom conveyor belt and moved from the air locking feeding port to the air locking discharging port without turning and causing particle breakage, the dust content in the flue gas is low, and the carbonization is completed during the rotation of the furnace bottom, and the continuous feeding and discharging are achieved. During the pyrolysis of the shield mud, the tar production amount can be reduced by 30%-70% due to the wrapping and adsorption effects, the gas generated during the pyrolysis of the biomass plays a pore-forming role, and the pore volume, pore size, and specific surface area in the mixed particles of the waste biomass and the shield mud can be controlled by controlling the pyrolysis temperature. The rotary bed pyrolysis furnace can effectively remove the organic matters such as surfactants and flocculants in the shield mud and convert the biomass into biomass charcoal.

[0012] The combustion system is provided with a gas burner, a combustion chamber, and an induced draft fan, the gas burner is used to preheat the pyrolysis carbonization furnace with natural gas at first, and then the pyrolysis gas is slowly input, the pyrolysis temperature required by the carbonization furnace is maintained by burning the pyrolysis gas, the hot air is input into the combustion chamber by the induced draft fan for combustion support, and the fuel utilization efficiency is improved.

[0013] The waste heat utilization system is provided with a waste heat boiler and an air preheater, the waste heat boiler recovers energy by using the 350-800℃ hot flue gas generated by the carbonization furnace, generates water vapor for drying the material in the belt dryer, and the 180-220℃ flue gas after energy recovery is input into the air preheater to generate hot air, the hot air is used in the dryer and the combustion chamber, and the cooled tail gas is input into the tail gas treatment system.

[0014] The cooling and discharging system is provided with a spiral water cooling machine, a cooling tower, and a water storage pool, the cooling tower is used to generate circulating cooling water for cooling the biomass charcoal-based water grass mud particles output by the pyrolysis carbonization furnace.

[0015] The screening and packaging system includes a particle size screening machine and a packaging machine, the biomass charcoal-based water grass mud is screened into particles of different particle sizes by the particle size screening machine, and is packaged into products of 0.5-20 kg / bag by the packaging machine for sale;

[0016] The tail gas treatment system comprises a bag filter and an absorption tower, tail gas output by a waste heat utilization system is removed of dust by the bag filter, and after removal of nitrogen oxides, sulfur dioxide and other polluted gases by the absorption tower, the tail gas is discharged up to the standard.

[0017] The electrical automatic control system adopts a central computer program control system and has a field monitoring function, and can control process parameters such as feeding and discharging devices, pyrolysis furnaces and burners according to process requirements by using frequency conversion regulation technology.

[0018] The biomass charcoal-based granular soil has a yield of 65-80%, mainly comprises silicon dioxide, iron oxide and aluminum oxide, and biomass charcoal, contains nutritional elements such as potassium, calcium, magnesium, nitrogen and phosphorus, has a pH of 6.9-7.9, a specific surface area of 20-150 m 2 / g, rich pore channels, is not easy to be pulverized after long-term soaking, is free of cleaning, does not mix water, and is black in color, and can be used as a breeding carrier for beneficial bacteria such as nitrifying bacteria and denitrifying bacteria.

[0019] Compared with the prior art, the biomass charcoal-based granular soil has the following advantages:

[0020] The production process system of the biomass charcoal-based water grass mud granules adopts a waste biomass and shield mud cooperative pyrolysis process, has the advantages of high production efficiency, high product value, few by-products and carbon sequestration and emission reduction. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The biomass charcoal-based water grass mud granule production process flowchart of the application.

[0022] Figure 2 The rotating bed pyrolysis furnace structure schematic diagram of the application.

[0023] Figure 3 The biomass charcoal-based water grass mud granule and its application diagram of the application.

[0024] Figure 4 The biomass charcoal-based water grass mud turbidity value diagram.

[0025] Figure 5 Germination rate diagram of biochar-based aquatic plant mud. Detailed implementation method:

[0026] The present invention is further illustrated below with specific implementation examples. These specific implementation examples are for illustrative purposes only and are not intended to limit the scope of the invention. The present invention can process tunnel boring machine mud and waste biomass. The following detailed description, in conjunction with the accompanying drawings, provides a detailed explanation of biomass-based aquatic plant mud particles and their production process system.

[0027] Example 1:

[0028] like Figure 1 The diagram shows the biomass charcoal-based aquatic plant mud pellet production process system of the present invention, which includes: a crusher, a storage hopper, a mixing and granulation system, a drying system, a pyrolysis system, a combustion system, a waste heat utilization system, a cooling and discharging system, a screening and packaging system, a tail gas treatment system, and an electrical automatic control system.

[0029] Rice straw is pulverized into powder with a particle size of less than 2 mm and stored in a storage hopper. Shield tunnel mud is stored in another storage hopper. Each storage hopper has a discharge port connected to a material mixing and granulation device. By controlling the discharge rate of the storage hoppers, the ratio of shield tunnel mud to rice straw is controlled, with rice straw accounting for 20% by mass. The mixture is prepared into spherical particles with a diameter of 3–6 mm. Continuous feeding and discharging can be achieved through frequency conversion control. The granulated raw material particles are then conveyed by a belt conveyor to a belt dryer for drying.

[0030] The belt dryer contains multiple layers of 40-mesh stainless steel wire mesh, stainless steel support rods, baffles, chains, a transmission device, and an exhaust fan. Heat exchange occurs between the raw material particles and counter-current hot air and steam through heat-conducting pipes. The drying exhaust gas is fed into a condenser via an exhaust fan for water-gas separation. Non-condensable gases are then passed through a heat exchanger into the combustion chamber for combustion. The dried material has a moisture content of 10%.

[0031] The pyrolysis carbonization system is equipped with a rotary bed pyrolysis furnace and a cyclone dust collector. The pyrolysis furnace is equipped with radiant heating tubes. Figure 2 Raw material particles 3 are fed into the furnace through the airlock inlet 2 and spread evenly on the conveyor belt at the bottom of the furnace. They then move from the inlet to the airlock outlet 1, where the rotating base 5 drives its rotation. The radiant tube burner 4 heats the material under oxygen-deficient conditions. The pyrolysis time is 1.5 hours, and the pyrolysis temperature is 600℃. Pyrolysis does not require turning over, preventing particle breakage. The flue gas has a low dust content and allows for continuous feeding and discharging. During the pyrolysis of shield tunnel mud, due to the encapsulation and adsorption effects, the tar production can be reduced by approximately 40% compared to the pyrolysis and carbonization of pure rice straw.

[0032] The combustion system is provided with a gas burner, a combustion chamber and an air blower. The gas burner is used to preheat the pyrolysis carbonization furnace to 600 DEG C with natural gas, and then slowly introduce pyrolysis gas to replace part of the natural gas to maintain the required pyrolysis temperature of the carbonization furnace. The hot air is introduced into the combustion chamber by the air blower to improve the fuel utilization efficiency.

[0033] The waste heat utilization system is provided with a waste heat boiler and an air preheater. The waste heat boiler recovers energy from the 600 DEG C hot flue gas generated by the carbonization furnace to generate water vapor for drying materials in the belt dryer. The 200 DEG C flue gas after energy recovery is introduced into the air preheater to generate hot air, which is used for the dryer and the combustion chamber. The cooled tail gas is introduced into the tail gas treatment system.

[0034] The cooling and discharging system is provided with a spiral water cooling machine, a cooling tower and a water storage pool. The cooling tower is used to generate circulating cooling water for cooling the biomass carbon-based water grass mud particles discharged from the pyrolysis carbonization furnace.

[0035] The screening system includes a particle size screening machine and a packaging machine. The biomass carbon-based water grass mud is screened into particles with particle sizes of 0-1 mm, 1-3 mm and 3-6 mm by the particle size screening machine, and packaged into products with weights of 0.5, 1, 5, 10 and 20 kg per bag by the packaging machine for sale.

[0036] The tail gas generated during the production process is removed of dust by a bag dust collector, and of nitrogen oxides, sulfur dioxide and other pollutants by an absorption tower, and then discharged in compliance with the standards.

[0037] The yield of the prepared biomass carbon-based granular soil is 73%, the elemental composition is shown in Table 1, the pH is 7.6, the specific surface area is 30 m 2 / g, the pores are rich, the soaking time is more than 12 months, the washing is free, the water is not muddy, and the color is black. Figure 3

[0038] Table 1 Main elemental composition of biomass carbon-based water grass mud granular soil

[0039] Element class (%) O C Si N Al Ca Mg Fe K P Biomass char-based water grass mud 52.9 12.6 17.0 0.2 5.9 0.8 0.2 3.8 0.5 0.1

[0040] Example 2:

[0041] 10g of 3-6mm biomass carbon-based water grass mud, traditional water grass mud, biomass carbon and shield mud were respectively weighed and placed in a 100ml conical flask.

[0042] 80ml of deionized water was added to the beaker, and then the beaker was placed in a shaker and shaken at a speed of 30r / min. After 30s, the supernatant was taken out and the turbidity value was measured by a turbidimeter.

[0043] ​The biomass charcoal-based water grass mud supernatant turbidity value is 34 NTU, the traditional water grass mud supernatant turbidity value is 57 NTU, the biomass charcoal supernatant turbidity value is 55 NTU, and the shield mud supernatant turbidity value is 103 NTU. Figure 4 )

[0044] Example 3

[0045] 50g of 3-6mm biomass charcoal-based water grass mud, traditional water grass mud and ceramsite were respectively weighed and placed in a circular glass jar with a diameter of 15cm, and were laid flat on the bottom.

[0046] Water was added to the glass jar until the biomass charcoal-based water grass mud was just submerged.

[0047] "Small opposite leaves" water grass seeds were scattered in the jar, the glass jar was sealed with plastic wrap, and an air hole was left on the plastic wrap.

[0048] The above glass jar was placed in a room with 1-2h of direct sunlight per day, and the temperature was 20-30℃.

[0049] The seven-day germination rate of "small opposite leaves" water grass seeds was 96% when the biomass charcoal-based water grass mud was used as the substrate, the seven-day germination rate of "small opposite leaves" water grass seeds was 79% when the traditional water grass mud was used as the substrate, and the seven-day germination rate of "small opposite leaves" water grass seeds was 72% when the ceramsite was used as the substrate. Figure 5 ).

[0050] In the above examples, the best embodiment of the present application is described, and it is obvious that many changes can be made on the basis of the present application, and it should be noted that any changes made under the concept of the present application will be within the scope of protection of the present application.

Claims

1. A method of producing a biomass-char based hydroseeding mud granule, characterized by, The production system of biomass charcoal-based water grass mud granules comprises: a pulverizer for crushing waste biomass; a mixing granulation system for mixing and granulating waste biomass and shield mud; a drying system for drying the mixed and granulated particles; a pyrolysis system for carbonizing the dried particles; a cooling and discharging system for cooling the carbonized particles; a screening and packaging system for screening the cooled particles; a tail gas treatment system connected with the pyrolysis system; a waste heat utilization system and a combustion system connected with the drying system and the pyrolysis system; a material mixing and stirring device and a granulation device are arranged in the mixing granulation system; the drying system is provided with a multi-layer belt dryer and a condenser; the pyrolysis system is provided with a rotating bed pyrolysis furnace and a cyclone dust collector, and the rotating bed pyrolysis furnace is provided with a radiation heating pipe; the combustion system is provided with a radiation pipe burner, a combustion chamber and an induced draft fan using natural gas and pyrolysis gas as fuel; the waste heat utilization system is provided with a waste heat boiler and an air preheater; the cooling and discharging system is provided with a water-cooled screw conveyor, a cooling tower and a water storage tank; the screening and packaging system comprises a particle size screening machine and a packaging machine; the tail gas treatment system comprises a bag dust collector and an absorption tower; the method comprises the following steps: first, crushing and storing waste biomass, then mixing and granulating waste biomass and shield mud, then drying and carbonizing the granular raw materials, cooling and screening, waste heat utilization and tail gas treatment, to obtain biomass charcoal-based water grass mud granules; the waste biomass is straw, forestry waste biomass or livestock and poultry manure, which is crushed by the pulverizer into powder with a particle size of less than 2 mm and then stored in a storage hopper; the shield mud is mud blocks generated during infrastructure construction.

2. The method of producing biomass-char based aquatic weed mud pellets according to claim 1, characterized by, The production system further comprises an electrical automatic control system, which adopts a central control system.

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