CN114405965A - A kind of method and equipment for separation and utilization of biogas residue - Google Patents

Abstract

The invention discloses a method for utilizing biogas residues according to quality and equipment thereof, wherein the biogas residues in a biogas residue storage bin are dried, dehydrated, pyrolyzed, carbonized, cooled, crushed and desalted by dissolving in water, and then solid-liquid separation is carried out to obtain a solid phase and a liquid phase, wherein the liquid phase is rich in salt and can obtain industrial salt by using a low-temperature distillation process, and the solid phase is subjected to acid leaching and solid-liquid separation to obtain a phosphorus-rich solution and a biochar adsorbing material; wherein, pyrolysis gas generated by pyrolysis and carbonization enters a combustion device to be combusted as energy of the pyrolysis device; after the flue gas generated by pyrolysis enters a No. 1 drying device as a drying and dehydrating energy source, the residual heat flue gas is sent to an evaporative crystallization device as an energy source for evaporative crystallization, and finally is sent to a No. 2 drying device as an energy source for drying a biochar adsorbing material, so that the cascade utilization of the energy source is realized; according to the invention, after the salt and the phosphorus are extracted from the pyrolyzed biogas residues, a good adsorption material is obtained, the deep resource utilization of the biogas residues is realized, and the method has good environmental benefits and economic benefits.

Description

A kind of method and equipment for separation and utilization of biogas residue

technical field

The invention relates to the technical field of anaerobic fermentation biogas residue resource utilization, in particular to a method and equipment for separating and utilizing biogas residue by quality.

Background technique

Anaerobic digestion to produce biogas is an effective way to deal with organic solid waste, but it faces the problem of how to deal with the subsequent recycling of biogas residues. Biogas residues contain a large amount of harmful substances, pathogens, antibiotics, and heavy metals (HMs), which, if not handled properly, may cause potential harm to the environment. Therefore, the safe disposal of biogas residue is an important link to realize the anaerobic digestion of organic solid waste. At present, the resource utilization of anaerobic digested biogas residues is mainly land use, and aerobic composting of biogas residues as a soil amendment is the most common. However, excessive application can easily lead to soil pollution and eutrophication of water bodies. Moreover, salt, harmful substances, heavy metals (HMs) and pathogens in digestate also bring potential ecological risks to the environment. Therefore, the development of biogas residue separation and utilization device is of great significance to realize its rapid reduction, harmlessness and resource utilization.

Regarding the utilization of pyrolysis resources of biogas residues, there have been relevant studies in China. CN202010258175.8 discloses a biochar prepared by pyrolysis of organic waste biogas residue and its recycling method. The prepared biochar is added as an additive to the anaerobic fermentation process of organic waste, which not only inhibits the acid production process, but also improves the gas production efficiency . CN201820597009.9 discloses a kind of equipment for anaerobic fermentation biogas residue carbonization, including biogas residue silo, drying pyrolysis cylinder, heating sleeve and carbon storage cylinder. It is pyrolyzed to form biochar. CN202022193363.5 discloses that the system for processing biogas residue and straw includes biogas residue cutting machine, drying device, straw pulverizer, combustion device, heating chamber and pyrolysis kiln, which can realize the pyrolysis of biogas residue and straw at the same time, but does not involve The quality and reuse of biogas residues. CN201410153239.2 discloses a method for preparing a modified biogas residue ammonia nitrogen adsorbent. The dehydrated and dried biogas residue is pulverized and sieved into biogas residue particles; the biogas residue particles are added into potassium hydroxide solution, mixed and dried; finally The dried product is heated and pyrolyzed in a nitrogen atmosphere. After the product is cooled, it is washed with hydrochloric acid, then washed with hot deionized water to neutrality, dried and then pulverized, ground and sieved to obtain the modified biogas residue. Ammonia nitrogen adsorbent. None of the above-mentioned patents relate to how to realize the quality separation and utilization device of biogas residue and its application method.

SUMMARY OF THE INVENTION

Therefore, in order to solve the above problems, the present invention provides a method and equipment for the utilization of biogas residues by quality. Chemical utilization can not only obtain salt resources and phosphorus resources, but also provide environmental protection materials for the purification and removal of organic pollutants in wastewater, which has good environmental and economic benefits.

In order to achieve the above purpose, the technical scheme of the present invention is as follows: a method for quality utilization of biogas residue, wherein the biogas residue in the biogas residue storage bin is subjected to drying and dehydration, pyrolysis carbonization, cooling, crushing and water-soluble desalination, A solid phase and a liquid phase are obtained by separation, the liquid phase is rich in salt, and industrial salt can be obtained by using a low-temperature distillation process, and the solid phase is subjected to acid leaching and solid-liquid separation to obtain a phosphorus-rich solution and a biochar adsorption material;

Among them, the pyrolysis gas generated by pyrolysis carbonization enters the combustion device to be burned as the energy source of the pyrolysis device; the flue gas generated by pyrolysis enters the 1# drying device as the energy for drying and dehydration, and the waste heat flue gas is then sent to the evaporative crystallization device as the evaporative crystallization device. The energy is finally sent to the 2# drying device as the energy for drying the biochar adsorption material to realize the cascade utilization of energy.

Further improvement, the biogas residue raw material is organic anaerobic fermentation biogas residue, preferably kitchen waste anaerobic fermentation biogas residue;

The drying and dehydration is specifically drying the material to a moisture content of less than 20%;

The temperature of the pyrolysis carbonization is 300～800℃;

The crushing is specifically grinding the biochar to a particle size of less than 100 mesh;

The solid-liquid ratio of the water-soluble desalination is 1:5 to 1:40;

In the acid leaching, the leaching solution is mixed with acid nitric acid or sulfuric acid and water, the solid-liquid ratio is 10-30 g/L, the temperature is 20-50 DEG C, and the time is 0.5-1 h.

Further improvement, the biochar obtained by pyrolysis and carbonization is sent to the cooling device, which is indirectly cooled by the air, and the hot air generated by the cooling device is sent to the combustion device as combustion air.

Further improvement, the steam generated by evaporative crystallization is cooled in the steam condensation device, the obtained aqueous solution is stored in the aqueous solution storage tank, and sent to the water-soluble desalination device for recycling.

A kind of equipment for separating and utilizing biogas residue, the equipment includes biogas residue storage bin, 1# conveying device, 1# drying device, 2# conveying device, pyrolysis device, cooling device, 8# conveying device, combustion device, 3# Conveying device, crushing device, 4# conveying device, water-soluble desalination device, 5# conveying device, 1# solid-liquid separation device, 17# conveying device, 6# conveying device, evaporative crystallization device, salt storage silo, acid solution storage tank, 11# delivery device, 2# aqueous solution storage tank, 12# delivery device, mixing device, 13# delivery device, phosphorus extraction device, 14# delivery device, 2# solid-liquid separation device, phosphorus-rich solution storage bin, 15# delivery device and 2# drying device;

The outlet of the biogas residue storage bin is connected to the inlet of the 1# conveying device, the outlet of the 1# conveying device is connected to the inlet of the 1# drying device, the outlet of the 1# drying device is connected to the inlet of the 2# conveying device, and the outlet of the 2# conveying device is connected to the inlet of the pyrolysis device. The outlet of the solution device is connected to the inlet of the cooling device and the inlet of the 1# drying device respectively, the outlet of the cooling device is respectively connected to the inlet of the 3# conveying device and the inlet of the 8# conveying device, the outlet of the 8# conveying device is connected to the inlet of the combustion device, and the combustion device is connected to the pyrolysis device; The outlet of the 1# drying device is also connected to the inlet of the 9# conveying device, the outlet of the 9# conveying device is connected to the inlet of the evaporative crystallization device, and the outlet of the evaporative crystallization device is connected to the inlet of the 2# drying device;

The outlet of the 3# conveying device is connected to the inlet of the crushing device, the outlet of the crushing device is connected to the inlet of the 4# conveying device, the outlet of the 4# conveying device is connected to the inlet of the water-soluble desalination device, the outlet of the water-soluble desalination device is connected to the inlet of the 5# conveying device, and the outlet of the 5# conveying device is connected to 1# The inlet of the solid-liquid separation device, the outlet of the 1# solid-liquid separation device are respectively connected to the inlet of the 17# conveying device and the inlet of the 6# conveying device, the outlet of the 6# conveying device is connected to the inlet of the evaporative crystallization device, and the outlet of the evaporative crystallization device is connected to the salt storage bin;

The outlet of the acid solution storage tank is connected to the inlet of the 11# delivery device, the outlet of the 2# aqueous solution storage tank is connected to the inlet of the 12# delivery device, the outlet of the 11# delivery device and the outlet of the 12# delivery device are connected to the inlet of the mixing device, and the outlet of the mixing device is connected to the 13# delivery device The inlet, the outlet of the 13# conveying device and the outlet of the 17# conveying device are connected to the inlet of the phosphorus extraction device; the outlet of the phosphorus extraction device is connected to the inlet of the 14 # conveying device, and the outlet of the 14 # conveying device is connected to the inlet of the 2 # solid-liquid separation device, and the 2 # solid-liquid separation device The outlet of the device is connected to the inlet of the 15# conveying device and the phosphorus-rich solution storage bin respectively, and the outlet of the 15# conveying device is connected to the inlet of the 2# drying device.

Further improvement, the equipment also includes a steam condensation device, a 1# aqueous solution storage tank and a 7# conveying device. The inlet of the steam condensation device is connected to the outlet of the evaporative crystallization device, the outlet of the steam condensation device is connected to the inlet of the 1# aqueous solution storage tank, and the outlet of the 1# aqueous solution storage tank. Connect the inlet of the 7# conveying device, and the outlet of the 7# conveying device is connected to the inlet of the water-soluble desalination device.

Further improvement, the equipment also includes a 16# conveying device, an adsorbent material storage bin, a flue gas purification device and a 10 # conveying device. The inlet of the 16 # conveying device and the inlet of the flue gas purification device are connected to the outlet of the 2 # drying device, and the 16 # conveying device The outlet is connected to the adsorption material storage silo. After the exhaust gas generated by the 2# drying device is purified by the flue gas purification device, it is transported to the chimney for discharge by the 10# conveying device connected to the outlet of the flue gas purification device.

Further improvement, the biogas residue storage silo is ordinary carbon steel silo or concrete silo;

The 1# conveying device and the 2# conveying device are shaftless screw conveyors, single-shaft screw conveyors or double-shaft screw conveyors;

The 1# drying device is an indirect heating vacuum drying or a rotary drum dryer;

The 3# conveyor device, 4# conveyor device, 15# conveyor device, 16# conveyor device and 17# conveyor device are shaftless screw conveyor, single-axis screw conveyor, double-axis screw conveyor, belt conveyor, scraper Board conveyors or pneumatic conveyors;

The pyrolysis device is an indirect heating rotary drum pyrolysis carbonization device;

The combustion device is an ordinary natural gas combustion furnace;

The 8# conveying device is a common exhaust fan;

The cooling device is an indirect air-cooled tube bundle heat exchanger, a spiral cooling device or a rotary drum cooling device;

The crushing device is a jet mill or a ball mill;

The water-soluble desalination device, the mixing device and the phosphorus extraction device are solid-liquid mixing tanks with a stirring device;

The 5# conveying device and the 14# conveying device are acid and alkali resistant mud pumps;

The 1# solid-liquid separation device and the 2# solid-liquid separation device are vacuum belt filter press, high pressure dehydrator, centrifugal separation dehydrator or plate and frame filter press;

The 6# conveying device, the 7# conveying device and the 12# conveying device are water pumps;

The evaporative crystallization device is an indirect heating crystallization device or a membrane distillation device;

The steam condensing device is an ordinary water steam condensing device;

The 1# aqueous solution storage tank and the 2# aqueous solution storage tank are ordinary carbon steel or stainless steel storage tanks, and can also be concrete pools;

The 9# conveying device and the 10# conveying device are ordinary flue gas fans;

The salt storage silo is ordinary carbon steel or stainless steel storage silo;

The flue gas purification device is a conventional dry or wet flue gas treatment device;

The acid solution storage tank is a stainless steel storage tank;

The 11# conveying device and the 13# conveying device are acid-resistant pumps.

The technical scheme provided by the invention has the following beneficial effects:

The invention can realize the utilization of biogas residues by quality and resources, reduces the preparation cost of the adsorption material, has strong applicability, and has good economic and environmental benefits, and specifically includes:

(1) The device can realize rapid reduction and disposal of biogas residue, with large processing capacity and high efficiency.

(2) The device obtains industrial salt and phosphorus elements from biogas residue as chemical raw materials, avoids the loss and pollution of salt, phosphorus and other elements, and realizes the quality and recycling.

(3) The adsorption material obtained by this device has good pore structure and rich surface functional groups, not only has good adsorption and decolorization ability, but also has the ability to adsorb salt in high brine, and the removal rate of antibiotics in wastewater can reach 90% above.

Description of drawings

Fig. 1 is the working flow schematic diagram of the present invention;

Fig. 2 is a bar graph showing the adsorption and removal rate of ciprofloxacin in solution by adsorbent material in Example 4 of the present invention.

Detailed ways

Preferred embodiments of the present invention will be described in more detail below. While the preferred embodiments of the present invention are described below, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.

Example 1

A method for the quality and utilization of biogas residues, wherein the biogas residues in the biogas residue storage bin are dried and dehydrated, pyrolyzed and carbonized, cooled, crushed and water-soluble desalinated, and then the solid phase and the liquid phase are obtained through solid-liquid separation, and the liquid phase is obtained. It is rich in salt, and industrial salt can be obtained by using a low temperature distillation process, and the solid phase is subjected to acid leaching and solid-liquid separation to obtain a phosphorus-rich solution and a biochar adsorption material.

Among them, the pyrolysis gas generated by pyrolysis carbonization enters the combustion device to be burned as the energy source of the pyrolysis device; the flue gas generated by pyrolysis enters the 1# drying device as the energy for drying and dehydration, and the waste heat flue gas is then sent to the evaporative crystallization device as the evaporative crystallization device. The energy is finally sent to the 2# drying device as the energy for drying the biochar adsorption material to realize the cascade utilization of energy.

Wherein, the biogas residue raw material is organic matter anaerobic fermentation biogas residue, preferably kitchen waste anaerobic fermentation biogas residue;

The drying and dehydration is specifically drying the material to a moisture content of less than 20%.

The temperature of the pyrolytic carbonization is 300-800°C.

The crushing is specifically grinding the biochar to a particle size of less than 100 mesh.

The solid-to-liquid ratio of the water-soluble desalination is 1:5-1:40; more preferably, the hydrothermal desalination method can be adopted, and the hydrothermal conditions are: the temperature is 120-180°C, and the time is 0.5-1h.

In the acid leaching, the leaching solution is mixed with acid nitric acid or sulfuric acid and water, the solid-liquid ratio is 10-30 g/L, the temperature is 20-50 DEG C, and the time is 0.5-1 h.

Specifically, the method for the quality and utilization of biogas residues includes the following steps:

S1. Perform aerobic pyrolysis on the biogas residue to obtain a pyrolysis residue; the method of the aerobic pyrolysis is to raise the temperature of livestock and poultry manure from room temperature to 600-800°C at a heating rate of less than 30°C/min, and at After constant temperature pyrolysis at this temperature for 0.5 to 1 h, it is cooled to room temperature with the furnace;

S2, the pyrolysis residue is crushed to a particle size of less than 100 mesh, and the crushed product is subjected to vibration leaching with an aqueous solution, and then a solid phase and a liquid phase are obtained through solid-liquid separation, and the solid phase is used for subsequent extraction of phosphorus elements, so The liquid phase is rich in salt, and the low-temperature distillation process can be used to obtain industrial salt, and the liquid phase can be recycled;

S3, adding weak acid dipping to the above-mentioned solid phase, leaching phosphorus, and then obtaining solid phase and liquid phase through solid-liquid separation, and after drying and crushing the solid phase, the particle size＜200 purpose product is selected as the antibiotic adsorption material, and in the liquid phase Phosphorus-rich elements can be recycled.

A device for realizing the above-mentioned biogas residue separation and utilization method, as shown in Figure 1, the device includes: biogas residue storage bin 1, 1# conveying device 2, 1# drying device 3, 2# conveying device 4, pyrolysis device 5. Combustion device 6, 8# conveyor device 7, cooling device 8, 3# conveyor device 9, crushing device 10, 4# conveyor device 11, water-soluble desalination device 12, 5# conveyor device 13, 1# solid-liquid separation device 14 , 6# conveying device 15, evaporative crystallization device 16, steam condensation device 17, 1 # aqueous solution storage tank 18, 7 # conveying device 19, 9 # conveying device 20, salt storage bin 21, flue gas purification device 22, 10 # conveying Device 23, chimney 24, 17# conveying device 25, acid solution storage tank 26, 11 # conveying device 27, 2 # aqueous solution storage tank 28, 12 # conveying device 29, mixing device 30, 13 # conveying device 31, phosphorus extraction device 32, 14# conveying device 33, 2 # solid-liquid separation device 34, 15 # conveying device 35, 2 # drying device 36, 16 # conveying device 37, adsorption material storage bin 38, phosphorus-rich solution storage bin 39.

The outlet of biogas residue silo 1 is connected to the inlet of 1# conveying device 2, the outlet of 1# conveying device 2 is connected to the inlet of 1 # drying device 3, the outlet of 1 # drying device 3 is connected to the inlet of 2 # conveying device 4, and the outlet of 2 # conveying device 4 is connected to the heat The inlet of the solution device 5, the outlet of the pyrolysis device 5 is connected to the inlet of the cooling device 8, the outlet of the cooling device 8 is respectively connected to the inlet of the 3# conveying device 9 and the inlet of the 8# conveying device 7, the outlet of the 8# conveying device 7 is connected to the inlet of the combustion device 6, and the combustion device 6 is connected to the pyrolysis device 5; the outlet of the 3# conveying device 9 is connected to the inlet of the crushing device 10, the outlet of the crushing device 10 is connected to the inlet of the 4# conveying device 11, the outlet of the 4# conveying device 11 is connected to the inlet of the water-soluble desalination device 12, and the outlet of the water-soluble desalination device 12 Connect the inlet of 5# conveying device 13, the outlet of 5# conveying device 13 is connected to the inlet of 1# solid-liquid separation device 14; the outlet of 1# solid-liquid separation device 14 is respectively connected to the inlet of 17 # conveying device 25 and the inlet of 6 # conveying device 15;

The outlet of 17# conveying device 25 is connected to the inlet of phosphorus extraction device 32, the outlet of 6# conveying device 15 is connected to the inlet of evaporative crystallization device 16, the outlet of evaporative crystallization device 16 is respectively connected to the salt storage bin 21 and the inlet of steam condensation device 17, and the outlet of steam condensation device 17 is connected 1# aqueous solution storage tank 18, the outlet of 1# aqueous solution storage tank 18 is connected to the inlet of 7# conveying device 19, and the outlet of 7# conveying device 19 is connected to the water-soluble desalination device 12; the outlet of 1# drying device 3 is also connected to the inlet of 9# conveying device 20, The outlet of the 9# conveying device 20 is connected to the inlet of the evaporative crystallization device 16, and the outlet of the evaporative crystallization device 16 is connected to the inlet of the 2# drying device 36;

The outlet of acid solution storage tank 26 is connected to the inlet of 11# conveying device 27, the outlet of 2# aqueous solution storage tank 28 is connected to the inlet of 12 # conveying device 29, the outlet of 11 # conveying device 27 and the outlet of 12 # conveying device 29 are connected to the inlet of mixing device 30, mixing The outlet of device 30 is connected to the inlet of 13# conveying device 31, the outlet of 13 # conveying device 31 is connected to the inlet of phosphorus extraction device 32, the outlet of phosphorus extraction device 32 is connected to the inlet of 14 # conveying device 33, and the outlet of 14 # conveying device 33 is connected to 2 # solid-liquid separation device The inlet of 34, the outlet of 2# solid-liquid separation device 34 are respectively connected to the inlet of 15# conveying device 35 and the phosphorus-rich solution storage bin 39, the outlet of 15# conveying device 35 is connected to the inlet of 2# drying device 36, and the outlet of 2# drying device 36 is connected to 16 #The inlet of the conveying device 37 and the inlet of the flue gas purification device 22, the outlet of the 16# conveying device 37 is connected to the adsorption material storage bin 38, and the exhaust gas generated by the 2# drying device 36 is purified by the flue gas purification device 22, and then the outlet of the flue gas purification device 22 The connected 10# conveying device 23 is conveyed to the chimney 24 for discharge.

Its workflow is as follows:

The biogas residue in the biogas residue storage bin 1 is transported to the 1# drying device 3 through the 1# conveying device 2 for drying and dehydration. The pyrolysis gas obtained from the solution directly enters the combustion device 6 and is burned as the energy source of the pyrolysis device 5; after the flue gas enters the 1# drying device 3 as the energy source of the drying and dehydration device, the waste heat flue gas is transported by the 9# conveying device 20 into the evaporation crystallization The device 16 is used as the energy source for evaporation and crystallization, and finally serves as the drying energy source for the 2# drying device 36 to realize the cascade utilization of energy.

The biochar obtained by pyrolysis is sent to the cooling device 8, and is indirectly cooled by the air. The hot air generated by the cooling device 8 is transported into the combustion device 6 through the 8# conveying device 7 as combustion air; the biochar obtained after cooling is passed through the 3#. The conveying device 9 is conveyed into the crushing device 10, and after being finely ground into biochar fine powder, it is conveyed into the water-soluble desalination device 12 by the 4# conveying device 11.

The biochar after water-soluble desalination treatment is transported from the 5# conveying device 13 to the 1# solid-liquid separation device 14 to achieve solid-liquid separation. #The conveying device 15 is transported into the evaporative crystallization device 16 to carry out the evaporative crystallization of salt, and the obtained salt is stored in the salt storage bin 21 as a chemical raw material; the steam generated by the evaporative crystallization is cooled in the steam condensing device 17, and the obtained aqueous solution is stored in the In the 1# aqueous solution storage tank 18, it is transported by the 7# conveying device 19 to the water-soluble desalination device 12 for recycling.

The acid in the acid solution solution storage tank and the water in the 2# aqueous solution storage tank 28 are respectively transported by the 11# conveying device 27 and 12 # conveying device 29 into the mixing device 30 for mixing, and the mixed solution is conveyed by the 13 # conveying device 31 to phosphorus The extraction device 32 is used as the leaching liquid required for phosphorus extraction; the mixed material in the phosphorus extraction device 32 is transported from the 14# conveying device 33 to the 2# solid-liquid separation device 34 for solid-liquid separation, and the liquid phase is a phosphorus-rich solution. The phosphorus-rich solution storage bin 39 can be used as a chemical raw material, and the solid phase is transported by the 15# conveying device 35 to the 2# drying device 36 for drying to obtain the biochar adsorption material, which is transported by the 16# conveying device 37. In the storage bin 38, it can be used for flue gas purification or sewage purification materials.

The flue gas tail gas from the exit of the 2# drying device 36 enters the flue gas purification device 22 for purification treatment, and is finally transported to the chimney 24 by the 10# conveying device 23 to achieve standard discharge.

1# conveying device refers to No. 1 conveying device, 2# conveying device refers to No. 2 conveying device, and so on for other devices.

in,

The biogas residue silo 1 is a common carbon steel silo or a concrete silo.

1# conveying device 2 and 2# conveying device 4 are shaftless screw conveyors, single-shaft screw conveyors or double-shaft screw conveyors.

1# drying device 3 is indirect heating vacuum drying or rotary drum dryer.

3# Conveyor 9, 4# Conveyor 11, 15# Conveyor 35, 16# Conveyor 37, 17# Conveyor 25 are Shaftless Screw Conveyor, Single Shaft Screw Conveyor, Double Shaft Screw Conveyor, Belt Conveyor machine, scraper conveyor or pneumatic conveyor.

The pyrolysis device 5 is an indirect heating rotary drum pyrolysis carbonization device.

The combustion device 6 is an ordinary natural gas combustion furnace.

8# conveying device 7 is a common exhaust fan.

The cooling device 8 is an indirect air-cooled tube bundle heat exchanger, a spiral cooling device 8 or a rotary drum cooling device 8 .

The crushing device 10 is a jet mill or a ball mill.

The water-soluble desalination device 12 , the mixing device 30 and the phosphorus extraction device 32 are solid-liquid mixing tanks with stirring devices.

The 5# conveying device 13 and the 14# conveying device 33 are acid and alkali resistant mud pumps.

1# solid-liquid separation device 14 and 2# solid-liquid separation device 34 are vacuum belt filter press, high pressure dehydrator, centrifugal separation dehydrator or plate and frame filter press.

6# conveying device 15, 7 # conveying device 19, 12 # conveying device 29 are water pumps.

The evaporative crystallization device 16 is an indirect heating crystallization device or a membrane distillation device.

The steam condensing device 17 is a common water vapor condensing device 17 .

The 1# aqueous solution storage tank 18 and the 2# aqueous solution storage tank 28 are ordinary carbon steel or stainless steel storage tanks, and may also be concrete pools.

The 9# conveying device 20 and the 10# conveying device 23 are common flue gas fans.

The salt storage bin 21 is a common carbon steel or stainless steel storage bin.

The flue gas purification device 22 is a conventional dry or wet flue gas treatment device.

The chimney 24 is a steel or concrete chimney 24 .

The acid solution storage tank 26 is a stainless steel storage tank.

The 11# conveying device 27 and the 13# conveying device 31 are acid-resistant pumps.

In the present invention, after pyrolysis of biogas residue to extract salt and phosphorus elements, a good adsorption material is obtained, and the deep resource utilization of biogas residue can be realized, which can not only obtain salt resources and phosphorus resources, but also provide adsorption for the removal of organic pollutants in wastewater. material, with good environmental and economic benefits.

Example 2 Salt water leaching recovery and residue use in biochar residues for high salt water adsorption

The kitchen anaerobic digester (DR) of a company in Guangdong was pyrolyzed at 300°C, cooled and finely ground to obtain digester pyrolysis residue (DR300), with a yield of 79.2%. The original anaerobic biogas residue and biogas residue pyrolysis residue DR300 were used for water-soluble desalination at a solid-liquid ratio of 1:40, and finally solid-liquid separation was carried out. The results show that in the liquid phase, the salt recovered from DR300 leaching accounts for 94.1% of the total salt in the biogas residue, which indicates that the water-soluble leaching method after pyrolysis of the kitchen anaerobic biogas residue can achieve a salt recovery rate of >94% .

Further, the residue after the obtained water eluting the salt is used for the adsorption of the incineration fly ash washing liquid, according to the solid-to-liquid ratio of 8ml/1g, the efficient removal of the salt in the incineration fly ash washing liquid can be realized, and the salt removal rate in the solution> 90%, the residue's salt adsorption capacity is >118.84mg/g. The above results show that the new device can realize the recovery and utilization of salt in biogas residue, and the obtained water-soluble leaching salt residue has the ability to circulate and adsorb high salt water, which has important guiding significance for application.

Example 3 Influence of desalination method on residue adsorption performance

The kitchen anaerobic digester (DR) of a company in Guangdong was pyrolyzed at 600°C and cooled, and then finely ground to obtain a digester pyrolysis residue with a yield of 79.2%. The pyrolysis residue is desalted in two ways: first, the biogas residue pyrolysis residue is mixed with a solid-liquid ratio of 1:40, and then the ordinary water is dissolved and desalted, and the water-soluble desalination residue is obtained after the liquid separation; The residues were mixed at a solid-liquid ratio of 1:40, and then hydrothermally heated at 180°C for 60 min, and the hydrothermal desalination residue was obtained after solid-liquid separation. With reference to "Wooden Activated Carbon Test Method" (GB/T 12496.10-1999), the adsorption amount of methylene blue on the two residues was determined, as shown in Table 1,

Table 1 Adsorption amount of methylene blue in solution by two kinds of residues

Methylene blue concentration (g/L) Water-eluted salt residue (mg/g) Hydrothermal desalination residue (mg/g) 1.5 18 22.5

The results in the table show that the adsorption capacity of methylene blue in the solution by the hydrothermal desalination residue is 25% higher than that of the ordinary water desalination residue, indicating that its adsorption capacity can be increased by 25%.

The two residues were further used for the adsorption of DR23 in the solution, and the adsorption conditions were: rotation speed 200 rpm, time 24 h, temperature 25 °C; initial concentration of DR23 was 20 mg/L. The results are shown in Table 2.

Table 2 Adsorption effect of two kinds of residues on DR23 solution

The above results show that the desalination residue obtained by hydrothermal desalination has a 16.6% increase in the adsorption capacity of DR23 in solution. Therefore, when the desalination method is selected, the method of hydrothermal desalination can be preferred.

Example 4

Using the above device scheme, the biogas residue was pyrolyzed at 400, 500, 600, 700 and 800 °C, and the pyrolysis residue was washed with water to obtain different adsorption materials, which were named DRC400, DRC500, DRC600, DRC700 and DRC800. Adsorption properties of the antibiotic ciprofloxacin. Take 0.1 g of 5 isosorbent materials and add them to 50 ml of ciprofloxacin solution with a concentration of 12 mg/L, and keep the mixture on an orbital shaker at a speed of 130 rpm for 2 hours, and filter the sample (0.22 water filter membrane). ) and used a UV/Vis spectrophotometer (Bio-Rad UV3000, USA) to analyze the concentration changes of ciprofloxacin before and after adsorption, as shown in Figure 2. The results showed that with the increase of the pyrolysis temperature, the adsorption effect of the obtained adsorption materials on ciprofloxacin in solution improved: among them, the adsorption materials prepared at 400 ℃ had a removal rate of 31.30% for CIP, and the adsorption materials prepared at 700 ℃ were 31.30%. The removal rate of CIP by the material increased to 99.42%, and the removal rate of the adsorption material prepared at 800 ℃ was 99.52%, indicating that when the above pyrolysis temperature was >700 ℃, the adsorption material obtained by this equipment system had a good adsorption effect on antibiotics in the solution.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and those of ordinary skill in the art will not depart from the principles and spirit of the present invention Variations, modifications, substitutions, and alterations to the above-described embodiments are possible within the scope of the present invention without departing from the scope of the present invention.

Claims (8)

1. a method for quality utilization of biogas residue, characterized in that: the biogas residue in the biogas residue storage bin is subjected to drying and dehydration, pyrolysis carbonization, cooling, crushing and water-soluble desalination, and then solid-liquid separation is carried out to obtain solid phase and liquid phase. The liquid phase is rich in salt, and industrial salt can be obtained by using a low-temperature distillation process, and the solid phase is subjected to acid leaching and solid-liquid separation to obtain a phosphorus-rich solution and a biochar adsorption material; Among them, the pyrolysis gas generated by pyrolysis carbonization enters the combustion device to be burned as the energy source of the pyrolysis device; the flue gas generated by pyrolysis enters the 1# drying device as the energy for drying and dehydration, and the waste heat flue gas is then sent to the evaporative crystallization device as the evaporative crystallization device. The energy is finally sent to the 2# drying device as the energy for drying the biochar adsorption material to realize the cascade utilization of energy. 2. The method for utilizing biogas residue by quality according to claim 1, characterized in that: the biogas residue raw material is organic anaerobic fermentation biogas residue; The drying and dehydration is specifically drying the material to a moisture content of less than 20%; The temperature of the pyrolysis carbonization is 300～800℃; The crushing is specifically grinding the biochar to a particle size of less than 100 mesh; The solid-liquid ratio of the water-soluble desalination is 1:5 to 1:40; In the acid leaching, the leaching solution is mixed with acid nitric acid or sulfuric acid, the solid-liquid ratio is 10-30 g/L, the temperature is 20-50° C., and the time is 0.5-1 h. 3. A method for quality utilization of biogas residue according to claim 1 or 2, characterized in that: the biochar obtained by pyrolysis and carbonization is sent to a cooling device, and is indirectly cooled by air, and the hot air generated by the cooling device is sent to a cooling device. into the combustion device as combustion air. 4. A method for quality utilization of biogas residue according to claim 1 or 2, characterized in that: the steam generated by evaporative crystallization is cooled in the steam condensing device, and the obtained aqueous solution is stored in an aqueous solution storage tank, and transported It is recycled into the water-soluble desalination device. 5. A device for quality and utilization of biogas residue, the device is used to realize the method for quality and utilization of biogas residue according to claim 1 or 2, characterized in that: the device comprises a storage bin for biogas residue, a 1# conveying device, a #Drying device, 2# conveyor device, pyrolysis device, cooling device, 8# conveyor device, combustion device, 3# conveyor device, crushing device, 4# conveyor device, water-soluble desalination device, 5# conveyor device, 1# solid-liquid Separation device, 17# conveying device, 6# conveying device, evaporative crystallization device, salt storage silo, acid solution storage tank, 11 # conveying device, 2 # aqueous solution storage tank, 12 # conveying device, mixing device, 13 # conveying device, Phosphorus extraction device, 14# conveying device, 2# solid-liquid separation device, phosphorus-rich solution storage silo, 15# conveying device and 2# drying device; The outlet of the biogas residue storage bin is connected to the inlet of the 1# conveying device, the outlet of the 1# conveying device is connected to the inlet of the 1# drying device, the outlet of the 1# drying device is connected to the inlet of the 2# conveying device, and the outlet of the 2# conveying device is connected to the inlet of the pyrolysis device. The outlet of the solution device is connected to the inlet of the cooling device and the inlet of the 1# drying device respectively, the outlet of the cooling device is respectively connected to the inlet of the 3# conveying device and the inlet of the 8# conveying device, the outlet of the 8# conveying device is connected to the inlet of the combustion device, and the combustion device is connected to the pyrolysis device; The outlet of the 1# drying device is also connected to the inlet of the 9# conveying device, the outlet of the 9# conveying device is connected to the inlet of the evaporative crystallization device, and the outlet of the evaporative crystallization device is connected to the inlet of the 2# drying device; The outlet of the 3# conveying device is connected to the inlet of the crushing device, the outlet of the crushing device is connected to the inlet of the 4# conveying device, the outlet of the 4# conveying device is connected to the inlet of the water-soluble desalination device, the outlet of the water-soluble desalination device is connected to the inlet of the 5# conveying device, and the outlet of the 5# conveying device is connected to 1# The inlet of the solid-liquid separation device, the outlet of the 1# solid-liquid separation device are respectively connected to the inlet of the 17# conveying device and the inlet of the 6# conveying device, the outlet of the 6# conveying device is connected to the inlet of the evaporative crystallization device, and the outlet of the evaporative crystallization device is connected to the salt storage bin; The outlet of the acid solution storage tank is connected to the inlet of the 11# delivery device, the outlet of the 2# aqueous solution storage tank is connected to the inlet of the 12# delivery device, the outlet of the 11# delivery device and the outlet of the 12# delivery device are connected to the inlet of the mixing device, and the outlet of the mixing device is connected to the 13# delivery device The inlet, the outlet of the 13# conveying device and the outlet of the 17# conveying device are connected to the inlet of the phosphorus extraction device; the outlet of the phosphorus extraction device is connected to the inlet of the 14 # conveying device, and the outlet of the 14 # conveying device is connected to the inlet of the 2 # solid-liquid separation device, and the 2 # solid-liquid separation device The outlet of the device is connected to the inlet of the 15# conveying device and the phosphorus-rich solution storage bin respectively, and the outlet of the 15# conveying device is connected to the inlet of the 2# drying device. 6. The equipment for separating and utilizing biogas residues according to claim 5, characterized in that: the equipment further comprises a steam condensing device, a 1# aqueous solution storage tank and a 7# conveying device, and the inlet of the steam condensing device is connected to the evaporative crystallization device The outlet, the outlet of the steam condensation device is connected to the inlet of the 1# aqueous solution storage tank, the outlet of the 1# aqueous solution storage tank is connected to the inlet of the 7# conveying device, and the outlet of the 7# conveying device is connected to the inlet of the water-soluble desalination device. 7. A device for separating and utilizing biogas residues according to claim 5, characterized in that: the device further comprises a 16# conveying device, an adsorption material storage bin, a flue gas purification device and a 10# conveying device, and the 16# conveying device The inlet of the device and the inlet of the flue gas purification device are connected to the outlet of the 2# drying device, and the outlet of the 16# conveying device is connected to the adsorption material storage bin. The 10# conveying device is conveyed to the chimney for discharge. 8. The equipment for separating and utilizing biogas residues according to any one of claims 5 to 7, wherein the biogas residue storage bins are ordinary carbon steel bins or concrete bins; The 1# conveying device and the 2# conveying device are shaftless screw conveyors, single-shaft screw conveyors or double-shaft screw conveyors; Described 1# drying device is indirect heating vacuum drying or rotary drum dryer; The 3# conveyor device, 4# conveyor device, 15# conveyor device, 16# conveyor device and 17# conveyor device are shaftless screw conveyor, single-axis screw conveyor, double-axis screw conveyor, belt conveyor, scraper Board conveyors or pneumatic conveyors; The pyrolysis device is an indirect heating rotary drum pyrolysis carbonization device; The combustion device is an ordinary natural gas combustion furnace; The 8# conveying device is a common exhaust fan; The cooling device is an indirect air-cooled tube bundle heat exchanger, a spiral cooling device or a rotary drum cooling device; The crushing device is a jet mill or a ball mill; The water-soluble desalination device, the mixing device and the phosphorus extraction device are solid-liquid mixing tanks with a stirring device; The 5# conveying device and the 14# conveying device are acid and alkali resistant mud pumps; The 1# solid-liquid separation device and the 2# solid-liquid separation device are vacuum belt filter press, high pressure dehydrator, centrifugal separation dehydrator or plate and frame filter press; The 6# conveying device, the 7# conveying device and the 12# conveying device are water pumps; The evaporative crystallization device is an indirect heating crystallization device or a membrane distillation device; The steam condensing device is an ordinary water steam condensing device; The 1# aqueous solution storage tank and the 2# aqueous solution storage tank are ordinary carbon steel or stainless steel storage tanks, and can also be concrete pools; The 9# conveying device and the 10# conveying device are ordinary flue gas fans; The salt storage silo is ordinary carbon steel or stainless steel storage silo; The flue gas purification device is a conventional dry or wet flue gas treatment device; The acid solution storage tank is a stainless steel storage tank; The 11# conveying device and the 13# conveying device are acid-resistant pumps.

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