Method for preparing nitrogen-rich liquid fertilizer and hydrothermal carbon from distillers' grains and application of nitrogen-rich liquid fertilizer and hydrothermal carbon

Abstract

The invention discloses a method for preparing nitrogen-rich liquid fertilizer and hydrothermal carbon from vinasse and application of the method, and the method comprises the following steps: adding the vinasse and a calcium-based conditioner into a hydrothermal kettle, introducing steam, and carrying out pyrohydrolysis reaction at 160-210 DEG C for 30-45 minutes; and carrying out solid-liquid separation on a product obtained by the pyrohydrolysis reaction, and collecting a liquid phase and a solid phase, the liquid phase being the nitrogen-rich liquid fertilizer, and the solid phase being the hydrothermal carbon. According to the method disclosed by the invention, main components (carbon and nitrogen) of the waste vinasse are effectively distributed in two phases under a relatively mild hydrothermal condition through a coupling effect of a calcium-based conditioner and a thermal condition, so that the prepared solid phase, namely the hydrothermal carbon, has low-nitrogen high-value fuel performance; meanwhile, unstable carbon and nitrogen components are decomposed and dissolved in a liquid phase, secondary heterocyclization and aromatization reactions of the carbon and nitrogen components are effectively avoided, nutritional ingredients are enriched in the liquid phase, the non-toxic fertilizer efficiency performance is achieved, and therefore all-component utilization of the waste vinasse is achieved.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and particularly relates to a method for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal by utilizing wine lees and application thereof. Background Art

[0002] Wine lees are the main by-product of the brewing light industry. They are the solid residue remaining after the soluble carbohydrates in the seeds of grains and fruits are extracted through fermentation, cooking and other processes. They are mainly divided into two categories: brewer's grains and white wine lees. Wine lees are a typical type of light industrial organic solid waste, with a high initial moisture content of more than 80wt.%, rich in perishable organic matter, and easy to deteriorate and breed bacteria and pathogens. However, dry wine lees are rich in protein and lignocellulose, with low ash and sulfur content. They can be regarded as concentrated carbon and nitrogen sources, reaching 45-50wt.% and 3-5wt.%, respectively, and belong to the category of high-quality biomass. How to achieve the effective disposal and utilization of this huge and increasing amount of high-humidity nitrogen-rich lignocellulosic biomass waste year by year, reduce the burden on enterprises, and reduce environmental impact has become a pain point that enterprises urgently need to solve and a hot topic of general concern in society.

[0003] At present, focusing on the essential properties of distiller's grains, the thermochemical resource is positioned, and the use of hydrothermal technology to convert it into high-value products is a feasible and potential disposal and utilization method. The existing technology mainly focuses on the preparation of biochar, activated carbon, biogas, carbon quantum dots, etc. by hydrothermal coupling with other means, which are applied in the fields of heating, energy storage, adsorption, etc. CN113549465A discloses a method for the combined disposal of distiller's grains and plastic waste using hydrothermal carbonization technology, and obtains hydrothermal carbon high-value solid fuel with a calorific value of 32.7-34.97MJ kg -1. CN109628158B authorizes a method for the graded thermochemical conversion of distiller's grains including hydrothermal carbonization to achieve source-end reduction of the raw material nitrogen component and process control of the conversion of gas-phase nitrogen pollutants, and obtain a high-value biogas with a nitrogen pollutant concentration of less than 20ppmv. CN117645850A discloses a method for distiller's grains hydrothermal carbon by dispersion and cross-linking treatment to obtain a formaldehyde-free adhesive for the field of artificial boards with a wet bonding strength of 1.35MPa. Although these technologies provide a variety of solutions for the resource utilization of distiller's grains solid-phase hydrothermal carbon, they generally have defects: they all ignore the disposal and utilization of a large amount of hydrothermal liquid generated by the hydrothermal process. For distiller's grains with high moisture content, the use of hydrothermal technology to achieve resource utilization, and the effective disposal or utilization of hydrothermal liquid is the key to restricting economic efficiency, environmental protection and engineering scale-up. CN114772578B authorizes a method for converting distiller's grains-derived hydrothermal carbon and hydrothermal liquid into capacitor carbon and carbon quantum dots by KOH activation and freeze-drying, respectively, to achieve high-value recycling of distiller's grains. Although this method takes into account the utilization of hydrothermal two-phase products, its practical application has obvious defects: the specific capacitance of capacitor carbon is too low, and the energy consumption of hydrothermal liquid drying containing carbon quantum dots is huge. CN110241142A mentions a method for hydrothermal carbonization coupled with anaerobic digestion to produce methane and high ammonia nitrogen carbon-based fertilizer. This method has similar problems: biochar is used to clean the hydrothermal liquid after anaerobic digestion to obtain clear water for reuse. The adsorption capacity of biochar is obviously not compatible with the removal of a large amount of hydrolyzed liquid ammonia nitrogen, and the biochemical treatment method of hydrothermal liquid is inefficient, and it is impossible to achieve clean and efficient disposal of the hydrothermal liquid phase.

[0004] In summary, the use of hydrothermal technology to achieve clean and efficient utilization of all components of wine lees must take into account the effective disposal of hydrothermal charcoal and hydrothermal liquid. The selection of application scenarios for the two types of products is crucial. In addition, for wine lees rich in protein and lignocellulose, the two-phase migration, transformation and distribution of carbon and nitrogen components are the key to giving the two types of products functional characteristics. Hydrothermal conditions are also an important factor affecting the non-toxicity of two-phase products. Existing technologies have not fully taken this into account and cannot be truly applied to engineering scenarios. Therefore, it is necessary to further develop clean and efficient hydrothermal technology, regulate the migration and transformation of carbon and nitrogen components in the products, and find suitable application outlets for solid-liquid two-phase products to achieve full component utilization of wine lees. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a method for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal using wine lees.

[0006] The invention also provides a nitrogen-rich liquid fertilizer.

[0007] The invention also provides application of the nitrogen-rich liquid fertilizer.

[0008] The invention also provides a hydrothermal charcoal.

[0009] The present invention also provides the application of the hydrothermal charcoal.

[0010] The invention also provides a method for promoting seed germination.

[0011] The invention also provides a method for promoting plant growth.

[0012] The invention also provides a process system for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal by utilizing wine lees.

[0013] The invention also proposes an application of the above process system.

[0014] According to one aspect of the present invention, a method for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal using wine lees is provided, the method comprising the following steps:

[0015] S1. Add vinasse and calcium-based conditioner into a hydrothermal kettle, introduce steam, and perform thermal hydrolysis at 160-210° C. for 30-45 min.

[0016] S2. The product obtained by the thermal hydrolysis reaction is subjected to solid-liquid separation, and the liquid phase and the solid phase are collected, wherein the liquid phase is nitrogen-rich liquid fertilizer, and the solid phase is hydrothermal charcoal.

[0017] In some embodiments of the present invention, the nitrogen-rich liquid fertilizer is a liquid fertilizer rich in nitrogen.

[0018] In some embodiments of the present invention, the calcium-based conditioning agent includes at least one of quicklime, phosphogypsum, shell powder and calcium-based bentonite.

[0019] In some embodiments of the present invention, the lees include brewer's lees and white distiller's lees.

[0020] In some embodiments of the present invention, the moisture content of the vinasse is 70-80%.

[0021] In some embodiments of the present invention, the moisture content of the vinasse is 75%.

[0022] In some embodiments of the present invention, the added mass ratio of the vinasse to the calcium-based conditioner is 1:0.0125-0.075.

[0023] In some embodiments of the present invention, the temperature of the steam is 180-220°C.

[0024] In some embodiments of the present invention, the raw material for the thermal hydrolysis reaction also includes water.

[0025] In some embodiments of the present invention, the input amount of the steam is 1-2.5 times that of the water.

[0026] In some embodiments of the present invention, the solid-liquid separation is performed using a filter press.

[0027] In some embodiments of the present invention, the filter press is a plate filter press.

[0028] In some embodiments of the present invention, the method further comprises the steps of adjusting the pH of the liquid phase, filtering and concentrating the liquid phase in sequence.

[0029] In some embodiments of the present invention, the regulator used for adjusting the pH includes acetic acid, phosphoric acid and ammonia water.

[0030] In some embodiments of the invention, the pH is 6.0-7.5.

[0031] In some embodiments of the present invention, the method further comprises a step of drying the solid phase.

[0032] In some embodiments of the present invention, the drying is performed by direct contact heat exchange with flue gas at 600-700° C. from a boiler.

[0033] In some embodiments of the present invention, the water content of the dried solid phase is less than 20 wt.%.

[0034] According to a second aspect of the present invention, a nitrogen-rich liquid fertilizer is provided, which is prepared by the above method.

[0035] In some embodiments of the present invention, the nitrogen content of the nitrogen-rich liquid fertilizer is 200-300 mg / L.

[0036] In some embodiments of the present invention, the nitrogen content of the nitrogen-rich liquid fertilizer is 230-280 mg / L.

[0037] In some embodiments of the present invention, the nitrogen content of the nitrogen-rich liquid fertilizer is 250 mg / L.

[0038] According to a third aspect of the present invention, an application of the nitrogen-rich liquid fertilizer is proposed, and the application is an application in promoting plant seed germination.

[0039] In some embodiments of the present invention, the use is for increasing the fresh weight and / or dry weight of a plant.

[0040] In some embodiments of the present invention, the application is application in promoting plant growth.

[0041] In some embodiments of the present invention, the plant includes but is not limited to soybean or rice.

[0042] According to a fourth aspect of the present invention, a method for promoting plant seed germination is proposed, the method comprising the following steps: applying the above-mentioned nitrogen-rich liquid fertilizer to the plant seeds.

[0043] In some embodiments of the present invention, the plant includes but is not limited to soybean or rice.

[0044] According to a fifth aspect of the present invention, a method for promoting plant growth is proposed, the method comprising the following steps: applying the above-mentioned nitrogen-rich liquid fertilizer to plants.

[0045] In some embodiments of the present invention, the plant includes but is not limited to soybean or rice.

[0046] According to a sixth aspect of the present invention, a hydrothermal carbon is provided, which is prepared by the above method.

[0047] In some embodiments of the present invention, the water content of the hydrothermal charcoal is less than 20 wt.%.

[0048] According to a seventh aspect of the present invention, an application of the hydrothermal charcoal is provided, wherein the application is application as a fuel.

[0049] According to an eighth aspect of the present invention, a process system for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal using wine lees is provided, the process system comprising a thermal hydrolysis unit, a solid-liquid separation unit, a liquid phase concentration unit, a drying unit and a combustion heating unit;

[0050] The thermal hydrolysis unit uses the high-temperature steam provided by the combustion heating unit to perform thermal hydrolysis on the lees to obtain a reaction liquid;

[0051] The solid-liquid separation unit is used to perform solid-liquid separation on the reaction liquid obtained by the thermal hydrolysis unit to obtain a liquid phase and a solid phase;

[0052] The liquid phase concentration unit is used to adjust the pH of the liquid phase obtained by the solid-liquid separation, and the liquid phase after the pH adjustment is filtered and concentrated in sequence to obtain nitrogen-rich liquid fertilizer;

[0053] The drying unit utilizes a drying device and the flue gas with a temperature of 600-700° C. from the combustion heating unit to perform contact heat exchange with the solid phase obtained by the solid-liquid separation to obtain hydrothermal charcoal with a moisture content of less than 20wt.%;

[0054] The combustion heating unit utilizes fuel and / or the hydrothermal charcoal obtained by the drying unit to burn and generate high-temperature flue gas; the high-temperature flue gas heats the water in the water supply device to generate 180-220°C steam which is supplied to the thermal hydrolysis unit, and then the high-temperature flue gas becomes 600-700°C flue gas and enters the drying unit.

[0055] In some embodiments of the present invention, the lees include brewer's lees and white distiller's lees.

[0056] In some embodiments of the present invention, the moisture content of the vinasse is 70-80%.

[0057] In some embodiments of the present invention, the moisture content of the vinasse is 75%.

[0058] In some embodiments of the present invention, the thermal hydrolysis reaction further comprises adding a calcium-based conditioning agent.

[0059] In some embodiments of the present invention, the calcium-based conditioning agent includes at least one of quicklime, phosphogypsum, shell powder and calcium-based bentonite.

[0060] In some embodiments of the present invention, the added mass ratio of the vinasse to the calcium-based conditioner is 1:0.0125-0.075.

[0061] In some embodiments of the present invention, the thermal hydrolysis unit includes a raw material tank, a reagent tank, a pre-reaction tank, a clean water tank and a hydrothermal kettle, wherein the raw material tank supplies vinasse, the reagent tank supplies calcium-based conditioner, and the clean water tank supplies clean water. The pre-reaction tank mixes the vinasse from the raw material tank, the calcium-based conditioner from the reagent tank, and the clean water from the clean water tank, and then transfers the mixture into the hydrothermal kettle for hydrothermal reaction.

[0062] In some embodiments of the present invention, the hydrothermal reactor is a two-pot alternating intermittent reactor. Specifically, when one reactor is in the reaction stage, the other reactor is loading or unloading, so as to ensure a continuous and stable supply of steam.

[0063] In some embodiments of the present invention, the solid-liquid separation unit comprises a filter press.

[0064] In some embodiments of the present invention, the filter press comprises a plate filter press.

[0065] In some embodiments of the present invention, the liquid phase concentration unit includes a liquid phase conditioning tank, a filtering device and a concentration device.

[0066] In some embodiments of the present invention, the liquid phase conditioning tank is used to adjust the pH of the liquid phase.

[0067] In some embodiments of the present invention, the regulator used for adjusting the pH includes acetic acid, phosphoric acid and ammonia water.

[0068] In some embodiments of the invention, the pH is 6.0-7.5.

[0069] In some embodiments of the present invention, the concentration device is a membrane concentration device. The membrane concentration device is used to purify nitrogen-rich liquid fertilizer, and the clean water obtained by the membrane concentration device is transferred to the clean water tank of the thermal hydrolysis reaction.

[0070] In some embodiments of the present invention, the drying unit includes a drying device and an air preheater.

[0071] In some embodiments of the present invention, the drying device comprises a drum dryer.

[0072] In some embodiments of the present invention, the air preheater is used to perform thermal combustion on the low-temperature flue gas obtained by heat exchange.

[0073] In some embodiments of the present invention, the air preheater comprises a tubular heat exchanger.

[0074] In some embodiments of the present invention, the fuel includes at least one of bituminous coal, anthracite and lignite.

[0075] In some embodiments of the invention, the fuel is lignite.

[0076] In some embodiments of the present invention, the lignite has a moisture content of 15-20 wt.%, and a calorific value of 4881-5186 kcal / kg.

[0077] In some embodiments of the present invention, the temperature of the low-temperature flue gas is 100-300°C.

[0078] In some embodiments of the present invention, the drying unit further comprises an induced draft fan and a bag filter to remove dust from the flue gas after the thermal combustion.

[0079] In some embodiments of the present invention, the combustion heating unit includes a boiler and a fuel premixing tank.

[0080] In some embodiments of the present invention, the boiler is a circulating fluidized bed boiler.

[0081] In some embodiments of the present invention, the combustion heat supply unit further comprises a water supply device, which is heated by high-temperature flue gas provided by the boiler to provide stable high-temperature steam to the thermal hydrolysis unit.

[0082] In some embodiments of the present invention, the temperature of the high temperature steam is 180-220°C.

[0083] In some embodiments of the present invention, a temperature sensor is provided on the pipe for providing flue gas in the combustion heat supply unit.

[0084] In some embodiments of the present invention, a steam flow meter is provided on the pipeline for providing high-temperature steam in the combustion heating unit.

[0085] In some embodiments of the present invention, a ground pump is provided in the fuel premixing bin for weighing the fuel.

[0086] In some embodiments of the present invention, the combustion heating unit is equipped with a certain proportion of coal in the solid phase hydrothermal charcoal, and burns in the boiler to generate heat energy, which is mainly used in two aspects: providing the required energy and reaction medium for the hydrothermal reaction in the form of high-temperature steam, and drying the hydrothermal charcoal in the form of medium-high temperature flue gas. This process can maintain the self-sufficiency of system energy with the input of a small amount of coal auxiliary fuel through the precise control of the heat supply of the two parts; in addition, during the combustion process, through the catalytic effect of the calcium-based components contained in the solid phase hydrothermal charcoal and the positive synergistic effect of co-combustion with coal, the conversion of nitrogen components contained in the hydrothermal charcoal to gaseous nitrogen pollutants can be doubly inhibited, thereby controlling the emission of nitrogen oxides in the tail gas. The flue gas treatment at the end of the process only requires simple dust removal measures to meet the emission standards, achieving real energy conservation and emission reduction.

[0087] According to an eighth aspect of the present invention, an application of the above process system is proposed, wherein the application is application in the preparation of nitrogen-rich liquid fertilizer and hydrothermal charcoal.

[0088] According to some embodiments of the present invention, at least the following beneficial effects are achieved: the method of the present invention effectively distributes the main components (carbon and nitrogen) of the waste lees to two phases under relatively mild hydrothermal conditions through the coupling effect of calcium-based conditioning agents and thermal conditions, giving the two phases a value-added role. On the one hand, the hydrothermal charcoal has low-nitrogen and high-value fuel properties through the enhanced quality improvement and nitrogen reduction effects on the solid phase; on the other hand, the unstable carbon and nitrogen components are decomposed and dissolved in the liquid phase, while effectively avoiding the secondary heterocyclization and aromatization reactions of the carbon and nitrogen components, so that the liquid phase is enriched with nutrients and has non-toxic fertilizer performance. By optimizing the coupling conditions of calcium conditioning agents and thermal factors, the hydrothermal and two-phase products of the lees can have resource potential, thereby realizing the full component utilization of the waste lees.

[0089] The scheme of the present invention adopts intermittent active thermal hydrolysis technology, combined with preferred membrane concentration, plate filter press, drum drying, and circulating fluidized bed combustion, with the help of a small amount of external auxiliary fuel and soft water, to meet the internal self-circulation and valorization of waste lees water, carbon, nitrogen and other components, and realize the on-site consumption of lees with zero by-product generation, which is suitable for small and medium-sized wineries with a lees production scale of 10-50t / d. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0091] Figure 1 This is a system process diagram in Example 1 of the present invention;

[0092] Figure 2This is a schematic diagram of the process flow in Example 1 of the present invention;

[0093] Figure 3 The component analysis diagram of the white wine grains and brewer grains in Example 1 of the present invention;

[0094] Figure 4 The composition diagram of the nitrogen-rich liquid fertilizer prepared from the brewer's grains in Example 5 of the present invention, wherein (a) is the NH4 in the conventional hydrothermal solution and the quicklime activated hydrothermal solution. + 、NO3 - 、NO2 - , DON (soluble organic nitrogen), TDN (dissolved nitrogen) concentration comparison results; (b) is the total organic phosphorus content comparison results, (c) is the total nitrogen content comparison results;

[0095] Figure 5 The figures are comparison results of seed germination and biomass under hydrothermal and control treatments in Example 5 of the present invention, wherein (a) is a figure showing the determination result of the number of germination of seeds treated with pure water control, (b) is a figure showing the determination result of the number of germination of seeds treated with urea control, (c) is a figure showing the determination result of the number of germination of seeds treated with conventional hydrothermal, (d) is a figure showing the determination result of the number of germination of seeds treated with quicklime activated hydrothermal, (e) is a figure showing the determination result of germination rate, (f) is a figure showing the determination result of bud length, (g) is a figure showing the determination result of average fresh weight, and (h) is a figure showing the determination result of average dry weight;

[0096] Figure 6 This is a graph showing the results of the thermal weight loss process of the co-combustion of brewer's grains hydrocharcoal and lignite in Example 6 of the present invention;

[0097] Figure 7 This is a diagram showing the quality test results of the hydrothermal charcoal in Example 6 of the present invention;

[0098] Figure 8 is the material balance diagram of the system in Example 7 of the present invention;

[0099] Fig. 9 This is the system energy balance diagram in Example 7 of the present invention. DETAILED DESCRIPTION

[0100] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0101] Example 1

[0102] This embodiment provides a process system for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal using waste lees, and the flow chart is as follows: Figure 1-2 As shown, it includes a thermal hydrolysis unit, a combustion heating unit, a solid phase drying unit, a solid-liquid separation unit and a liquid phase concentration unit.

[0103] (1) Thermal hydrolysis unit: including a raw material tank, a reagent tank, a pre-reaction tank, a clean water tank and a hydrothermal reactor. The hydrothermal reactor contains an agitator and the reactor adopts a two-pot alternating intermittent reactor. When one pot is in the reaction stage, the other pot is loading or unloading to ensure a continuous and stable supply of steam. The specific use process of the thermal hydrolysis unit is as follows:

[0104] Waste lees with a moisture content of 75% (either beer lees from a brewery or white wine lees from a liquor factory, with a composition such as Figure 3 As shown, in this embodiment, brewer's grains are selected and loaded into the raw material tank, the calcium-based conditioning agent (quicklime, phosphogypsum, shell powder or calcium-based bentonite can be used, and quicklime is used in this embodiment) is loaded into the reagent tank, and clean water is loaded into the clean water tank; the mass ratio of the materials is 1:0.05:0.6 (1:0.0125-0.075:0.5-1 can be used) is fully premixed by the respective feed pumps, and loaded into the reactor, and the material loading amount is 70-80% of the effective volume of the reactor, and the agitator is started to mix evenly. The reactor is then closed to form a closed environment. The saturated steam from the boiler system is introduced into the reactor to mix and contact with the materials. Under the action of the agitator, the materials are heated to the set temperature and react. The whole process lasts for 30 minutes (30-45 minutes is acceptable). The reaction temperature is 180°C (160-210°C is acceptable). The saturated steam temperature is 200°C. The steam input is 1.6 times (1-2.5 times) of the water supplement. After the reaction, a solid-liquid mixed product is obtained.

[0105] (2) Solid-liquid separation unit: contains a plate filter press. The specific working process is as follows:

[0106] The solid-liquid mixed product obtained above is transported to the solid-liquid separation unit (plate filter press) through a pipeline by a screw pump for separation, and the filtrate enters the liquid phase conditioning tank. The high-humidity hydrothermal charcoal is transported to the solid phase drying unit by a screw feeder. The moisture content of the hydrothermal charcoal is 70-80%.

[0107] (3) Liquid phase concentration unit: It includes a liquid phase conditioning tank, a filtration device and a membrane concentration unit. The specific use process of the liquid phase concentration unit is as follows:

[0108] In the liquid phase conditioning tank, a neutralizer (weak acid (acetic acid or phosphoric acid, pH 2.4) or weak base (ammonia pH 6.0-7.5)) from the acid-base tank is added to adjust the pH of the filtrate to be weakly alkaline or neutral. After filtration, it is transported to the membrane concentration unit by a liquid phase pump for purification to obtain nitrogen-rich liquid fertilizer, which is stored in a finished product tank. The clean water obtained by membrane concentration is pumped into a clean water tank, wherein the membrane concentration unit adopts an ultrafiltration device.

[0109] (4) Drying unit: includes drum dryer, air preheater (tubular heat exchanger), induced draft fan and bag filter. The specific working process is as follows:

[0110] The high-humidity hydrothermal charcoal obtained in the above (2) is directly contacted with the medium-high temperature flue gas (600-700°C) from the boiler combustion unit for heat exchange in a drum dryer to obtain fuel charcoal with a moisture content of less than 20wt.%. The low-temperature flue gas (100-300°C) after heat exchange enters the air preheater to preheat the combustion air, and is then transported to the bag filter (outlet flue gas temperature>100°C) through the induced draft fan and discharged from the chimney after dust removal.

[0111] (5) Combustion heating unit: including circulating fluidized bed boiler, fuel premixing tank and water supply device (soft water tank). The specific working process is as follows:

[0112] Lignite (bituminous coal, anthracite, and lignite are all acceptable) is used in a circulating fluidized bed boiler to generate high-temperature flue gas, or the fuel charcoal with a moisture content of less than 20wt.% obtained after drying in the above (4) is mixed with lignite (bituminous coal, anthracite, and lignite are all acceptable) in a fuel premixing bin at a mass ratio of 1:1 (1:1-1:3 are all acceptable), and mixed combustion is carried out under the action of preheated combustion-supporting air to generate high-temperature flue gas; the flue gas passes through the water-cooled wall and superheater of the boiler in turn to heat the soft water in the soft water tank to generate saturated steam with a temperature of 200°C; the medium-temperature flue gas after heating the soft water is sent to a drying unit, and the generated saturated steam is sent to a thermal hydrolysis unit.

[0113] The flue gas at each stage is equipped with temperature sensors to monitor the temperature, and steam flow meters to monitor the steam temperature and flow.

[0114] The fuel is in the fuel premixing bin and is transported to the boiler burner by belt conveyor and screw feeder. The fuel charcoal and coal added to the fuel premixing bin are weighed by ground pump.

[0115] Example 2

[0116] This embodiment provides a process system for preparing nitrogen-rich liquid fertilizer using waste vinasse, which is different from Embodiment 1 only in that no calcium-based conditioner is added to the thermal hydrolysis unit.

[0117] Example 3

[0118] This embodiment provides a method for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal using waste wine lees, and nitrogen-rich liquid fertilizer and hydrothermal charcoal prepared by the above method. The method comprises the following steps: using the process system provided in Example 1, nitrogen-rich liquid fertilizer and hydrothermal charcoal are prepared. Specifically, the following steps are included:

[0119] (1) Waste distiller's grains with a moisture content of 75% (beer grains from breweries and distiller's grains from distilleries, with a composition such as Figure 1 The raw material tank is filled with calcium-based conditioning agent (quicklime, phosphogypsum, shell powder or calcium-based bentonite, quicklime is used in this embodiment) and the clean water tank is filled with clean water; the materials are fully premixed by respective feed pumps at a mass ratio of 1:0.05:0.6 (1:0.0125-0.075:0.5-1 is all right) and loaded into the reactor, the material loading amount is 70-80% of the effective volume of the reactor, the agitator is started to mix evenly, the reactor cover is closed to form a closed environment. The saturated steam from the boiler system is introduced into the reactor, mixed with the material, and the material is heated to the set temperature and reacted under the action of the agitator. The whole process lasts for 30 minutes (30-45 minutes is all right), the reaction temperature is 180°C (160-210°C is all right), the saturated steam temperature is 200°C, the steam input is 1.6 times (1-2.5 times) of the water supplement, and a solid-liquid mixed product is obtained after the reaction is completed.

[0120] (2) The solid-liquid mixed product obtained above is transported to a solid-liquid separation unit (plate filter press) through a pipeline by a screw pump for separation, and the filtrate enters a liquid phase conditioning tank. The high-humidity hydrothermal charcoal is transported to a solid phase drying unit by a screw feeder. The moisture content of the hydrothermal charcoal is 70-80%.

[0121] (3) In the liquid phase conditioning tank, add the neutralizer (weak acid (acetic acid or phosphoric acid, pH 2.4) or weak base (ammonia pH 6.0-7.5)) from the acid-base tank to adjust the pH of the filtrate to be weakly alkaline or neutral. After filtration, the filtrate is transported to the membrane concentration unit by a liquid phase pump for purification to obtain nitrogen-rich liquid fertilizer, which is stored in the finished product tank. The clean water obtained by membrane concentration is pumped into the clean water tank.

[0122] (4) The high-humidity hydrothermal charcoal obtained in the above (2) is directly contacted with the medium-high temperature flue gas (600-700°C) from the boiler combustion unit for heat exchange to obtain fuel charcoal with a moisture content of less than 20wt.%. The low-temperature flue gas (100-300°C) after heat exchange enters the air preheater to preheat the combustion air, and is then transported to the bag filter (outlet flue gas temperature>100°C) through the induced draft fan and discharged from the chimney after dust removal.

[0123] (5) The fuel charcoal with a moisture content of less than 20 wt.% obtained after drying in the above (4) is mixed with lignite (bituminous coal, anthracite, and brown coal) in a mass ratio of 1:1 (1:1-1:3), and mixed combustion is carried out under the action of preheated combustion air to generate high-temperature flue gas, which passes through the water-cooled wall and superheater of the boiler in turn to heat the soft water from the soft water tank to generate saturated steam with a temperature of 200°C. The medium-temperature flue gas that has heated the soft water is sent to the drying unit, and the generated saturated steam is sent to the thermal hydrolysis unit.

[0124] Example 4

[0125] This embodiment provides a method for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal using waste wine lees, and nitrogen-rich liquid fertilizer and hydrothermal charcoal prepared by the above method. The method comprises the following steps: using the process system provided in Example 2, preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal.

[0126] Example 5

[0127] This embodiment provides the use of the nitrogen-rich liquid fertilizer prepared in the above embodiments 3 and 4 in promoting seed germination and promoting plant growth.

[0128] 1. Analysis of physical and chemical components

[0129] The nitrogen-rich liquid fertilizers prepared in Example 3 (quicklime activated hydrothermal solution) and Example 4 (conventional hydrothermal solution) were analyzed for physical and chemical components. Specifically, NH4 + 、NO3 - 、NO2 - , DON (soluble organic nitrogen), TDN (dissolved nitrogen), total organic phosphorus content and total nitrogen content.

[0130] The results are as follows Figure 4 As shown in the figure, it can be seen that the nitrogen concentration and total phosphorus concentration of the nitrogen-rich liquid fertilizer prepared in Example 3 are significantly better than those in Example 4.

[0131] 2. Seed germination test

[0132] Experimental method: Soybean seeds (Zhonghuang 57) were used as experimental materials. During the test, the seeds were divided into 4 groups (64 seeds in each group), disinfected with 75% ethanol for 30 seconds, and then washed three times with sterile water. The seeds were placed on the seedling tray of the seed germination planting box. In each group of the planting box, an equal volume of pure water (CK1), urea (CK2, 0.5 g / L) with the same nitrogen concentration as the nitrogen-rich liquid fertilizer prepared in Example 3 (quicklime active hydrothermal solution), and an equal volume of nitrogen-rich liquid fertilizer (BSG-180) prepared in Example 4 (conventional hydrothermal solution) with the nitrogen-rich liquid fertilizer prepared in Example 3 (quicklime active hydrothermal solution) and nitrogen-rich liquid fertilizer (BSG-Ca(OH)2) (nitrogen content of 250 mg / L) were added to cover the soybean seeds. According to the nitrogen concentration of the commonly used plant nutrient solution (Kimura B), the hydrothermal solution was diluted 10 times for the experiment. After 5 days, the number of germinations, germination rate, average plant fresh weight, average plant dry weight, and sprout length distribution of seeds in different groups were counted.

[0133] The results are as follows Figure 5 As shown in the figure, it can be seen that the nitrogen-rich liquid fertilizer prepared in Example 3 effectively increases the number and germination rate of seeds, promotes the growth of buds, and increases the dry weight and fresh weight of seeds after germination compared with the control group and Example 4.

[0134] Example 6

[0135] In this example, the quality of the hydrothermal charcoal prepared in the above example 3 was measured.

[0136] 1. Determination of the combustion effect of hydrothermal charcoal and lignite mixture

[0137] Experimental method: After mixing hydrothermal charcoal and lignite in a ratio of 1:1, the combustion effect was tested using an online thermogravimetric analyzer.

[0138] The experimental results are as follows Figure 6 As shown in the figure, it can be seen that during the co-combustion of hydrothermal charcoal and lignite, the weight loss is more uniform in the entire combustion temperature range compared to the combustion of the raw materials, possibly due to the hydrolysis of non-lignocellulose components such as proteins or polysaccharides, and the burnout temperature is lower, which means that the combustion is more uniform and rapid.

[0139] 2. Quality determination of hydrothermal charcoal

[0140] Experimental method: The elemental composition and industrial composition of hydrothermal charcoal were measured using an elemental analyzer and an industrial analyzer, and the quality of the hydrothermal charcoal was calculated.

[0141] The experimental results are as follows Figure 7As shown in the figure, it can be seen that as the hydrothermal temperature increases, the hydrothermal charcoal yield decreases accordingly, and the decrease rate is the smallest in the range of 180-210℃. The volatile matter in the hydrothermal charcoal also decreases, and the fixed carbon increases, which also verifies the downward trend of the hydrothermal charcoal yield, and the calorific value and fuel ratio continue to increase. From the perspective of calorific value, after hydrothermal carbonization at high hydrothermal temperature, the calorific value of hydrothermal charcoal has exceeded that of lignite, and even reached the calorific value of bituminous coal, indicating that the hydrothermal carbonization of brewer's grains has a significant effect on improving the quality. The energy density of hydrothermal charcoal is significantly improved, and the denitrification efficiency is also high. The increase in hydrothermal temperature may enhance the decarboxylation and dehydroxylation reactions of brewer's grains. At low temperatures, dehydroxylation is the main reaction, while at high temperatures, decarboxylation is the main reaction.

[0142] Example 7

[0143] This example calculates the material balance and energy balance of each step of the process system obtained in the above-mentioned Example 1.

[0144] 1. Logistics accounting

[0145] Experimental method: Based on the experimental conclusions, system operation requirements and equipment parameters provided by the equipment supplier, calculate the flow of materials during system operation.

[0146] The experimental results are as follows Figure 8 As shown in the figure, the data unit is t / a. It can be seen from the figure that the brewer's grains raw material first undergoes hydrothermal reaction with soft water, nitrogen fixer and steam, and a thermal hydrolysis product is obtained after a loss of 7% of the total mass. The thermal hydrolysis product is separated into solid phase products and liquid phase products after filter pressing, and a loss of 3% is generated at the same time. The liquid phase product is separated into organic liquid fertilizer products and waste liquid after neutralization, concentration and purification. The waste liquid can be used to supply the water required for the hydrothermal reaction. After the solid phase product loses water through drying treatment, it is mixed and burned with a certain amount of lignite and air in the furnace to generate high-temperature flue gas; the high-temperature flue gas heats the soft water in the pot to produce high-temperature steam. After the flow of flue gas and steam is adjusted, the flue gas is used to dry the solid phase product and preheat the air. During this period, the flue gas only exchanges heat with the outside world and does not produce mass loss, so it is not shown in the logistics diagram; the steam is sent to the hydrothermal kettle for the hydrothermal reaction of the next batch of raw materials. The above system operates in a cycle, and the high-temperature steam, high-temperature flue gas, water and other materials required for this cycle are all provided by the previous round of reaction, thereby realizing a self-heating process system for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal using wine grains.

[0147] 2. Energy flow calculation

[0148] Experimental method: Based on the logistics measurement and calculation results, the flow of energy during the system operation is studied.

[0149] The experimental results are as follows Fig. 9As shown, the data unit in the figure is MJ / d. Since this system involves chemical changes, chemical energy is added in the process of energy heat flow, which is represented by dotted lines in the figure for distinction. It can be seen from the figure that the system in the energy flow analysis includes three main units, namely, hydrothermal kettle, drum dryer and boiler. High-temperature steam inputs heat into the hydrothermal kettle. Heat is lost in three forms: reaction heat required to heat the substance in the hydrothermal reaction, heat dissipation of the furnace during the reaction process, and waste heat of the product. This is because in the boiler, soft water is converted from saturated water at 20°C to saturated steam at 200°C by heat absorption, while in the hydrothermal kettle, high-temperature steam at 200°C is converted into saturated water at 180°C by heat release, and the energy difference is stored in the product in the form of product waste heat. The product of the hydrothermal reaction, hydrothermal charcoal, and the additional lignite are burned to convert their own chemical energy into heat and input into the boiler. 15% of the heat in the boiler flows out as the heat loss of the boiler itself, and the remaining 85% of the heat is converted into energy carried by high-temperature steam and high-temperature flue gas. The heat of the high-temperature steam will be used for the hydrothermal reaction in the next cycle; the heat of the high-temperature flue gas will be used to dry the hydrothermal charcoal in the next cycle. Part of the heat is absorbed by the water in the charcoal, causing it to evaporate, and the remaining heat is discharged with the exhaust gas.

[0150] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A method for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal using wine lees, characterized in that: The method comprises the following steps: S1. Add vinasse and calcium-based conditioner into a hydrothermal kettle, introduce steam, and perform thermal hydrolysis at 160-210° C. for 30-45 min. S2. The product obtained by the thermal hydrolysis reaction is subjected to solid-liquid separation, and the liquid phase and the solid phase are collected, wherein the liquid phase is nitrogen-rich liquid fertilizer, and the solid phase is hydrothermal charcoal.

2. The method according to claim 1, characterized in that The calcium-based conditioning agent includes at least one of quicklime, phosphogypsum, shell powder and calcium-based bentonite; And / or, the added mass ratio of the vinasse to the calcium-based conditioner is 1:0.0125-0.

075. And / or, the temperature of the steam is 180-220°C; And / or, the raw material of the thermal hydrolysis reaction also includes water; And / or, further comprising the steps of adjusting the pH of the liquid phase, filtering and concentrating the liquid phase in sequence; And / or, further comprising the step of drying the solid phase; Preferably, the drying is carried out by direct contact heat exchange with 600-700°C flue gas from a boiler; Preferably, the water content of the dried solid phase is less than 20 wt.%.

3. A nitrogen-rich liquid fertilizer, characterized in that: Prepared by the method of claim 1 or 2; Preferably, the nitrogen content of the nitrogen-rich liquid fertilizer is 200-300 mg / L.

4. Use of the nitrogen-rich liquid fertilizer according to claim 3 in any of the following: (1) Promote plant seed germination; (2) increasing the fresh weight and / or dry weight of the plant; (3) Promote plant growth.

5. A method for promoting plant seed germination, characterized in that: The method comprises the following steps: applying the nitrogen-rich liquid fertilizer according to claim 3 to plant seeds.

6. A method for promoting plant growth, characterized in that: The method comprises the following steps: applying the nitrogen-rich liquid fertilizer according to claim 3 to plant seeds.

7. A hydrothermal charcoal, characterized in that: The method is prepared by the method of claim 1 or 2.

8. Use of the hydrothermal charcoal according to claim 7 as fuel.

9. A process system for preparing nitrogen-rich liquid fertilizer and hydrothermal charcoal using wine lees, characterized in that: The process system includes a thermal hydrolysis unit, a solid-liquid separation unit, a liquid phase concentration unit, a drying unit and a combustion heating unit; The thermal hydrolysis unit uses the high-temperature steam provided by the combustion heating unit to perform thermal hydrolysis on the lees to obtain a reaction liquid; The solid-liquid separation unit is used to perform solid-liquid separation on the reaction liquid obtained by the thermal hydrolysis unit to obtain a liquid phase and a solid phase; The liquid phase concentration unit is used to adjust the pH of the liquid phase obtained by the solid-liquid separation, and the liquid phase after the pH adjustment is filtered and concentrated in sequence to obtain nitrogen-rich liquid fertilizer; The drying unit utilizes a drying device and the flue gas with a temperature of 600-700° C. from the combustion heating unit to perform contact heat exchange with the solid phase obtained by the solid-liquid separation to obtain hydrothermal charcoal with a moisture content of less than 20wt.%; The combustion heating unit uses fuel and / or the hydrothermal charcoal obtained by the drying unit to burn and generate high-temperature flue gas; the high-temperature flue gas heats the water in the water supply device to generate steam at 180-220°C, which is supplied to the thermal hydrolysis unit, and the high-temperature flue gas becomes flue gas at 600-700°C and enters the drying unit; Preferably, the thermal hydrolysis unit comprises a raw material tank, a reagent tank, a pre-reaction tank, a clean water tank and a hydrothermal kettle, wherein the raw material tank supplies vinasse, the reagent tank supplies calcium-based conditioning agent, the clean water tank supplies clean water, and the pre-reaction tank mixes the vinasse from the raw material tank, the calcium-based conditioning agent from the reagent tank, and the clean water from the clean water tank, and then transfers the mixture to the hydrothermal kettle for hydrothermal reaction; Preferably, the solid-liquid separation unit comprises a filter press; Preferably, the liquid phase concentration unit comprises a liquid phase conditioning tank, a filtering device and a concentrating device; Preferably, the drying unit comprises a drying device and an air preheater; Preferably, the combustion heating unit comprises a boiler and a fuel premixing bin; Preferably, the fuel comprises at least one of bituminous coal, anthracite and lignite.

10. Use of the process system according to claim 9 in the preparation of nitrogen-rich liquid fertilizer and / or hydrothermal charcoal.

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