CN101830617B - Methane production, desulfuration and denitrification integrated device - Google Patents

Abstract

The invention discloses a biogas production-desulfurization-denitrification integrated device. It includes biogas production area I, three-phase separation area II, desulfurization-denitrification area III and nitrification wastewater storage tank. Biogas production area I is equipped with sludge discharge pipe, water inlet pipe, sampling pipe and return pipe; three-phase separation area II is equipped with There are sludge settling chamber, inverted funnel-shaped three-phase separator, first air chamber, first overflow outlet pipe and biogas collection and monitoring pipe; the main body of desulfurization-denitrification zone III includes the first desulfurization-denitrification cylinder and the second desulfurization-denitrification cylinder. The denitrification cylinder is composed of a sludge bucket, a disc gas distributor, a biogas input pipe, a second overflow outlet pipe, a sulfur discharge pipe, a purified biogas constant pressure pipe, a second air chamber, a third air chamber, and the nitrification waste water flowing freely. pipes and biogas collection pipes. The advantages of this device are: ① biogas production and desulfurization and denitrification are integrated, and biogas is produced while desulfurization is performed without air pump transportation; ② H ₂ S is oxidized into elemental sulfur, which can recycle sulfur resources; Eliminate nitrogen pollution.

Description

Biogas production-desulfurization-denitrification integrated device

technical field

The invention relates to a biogas production-desulfurization-denitrification integrated device, which is suitable for biogas projects, organic wastewater anaerobic treatment projects and the like. the

Background technique

Biogas fermentation is one of the important means of organic wastewater treatment. Biogas fermentation technology is favored by environmental engineering circles due to low operating costs, low sludge output, and recyclable biogas. Domestic sewage contains 3-6mg/L organic sulfur and 30-60mg/L inorganic sulfur, and the sulfate content of some industrial organic wastewater (such as pulp wastewater, tannery wastewater, pharmaceutical wastewater, etc.) is even as high as 9000mg/L or more. During the anaerobic biological treatment of these sulfur-containing wastewater, a large amount of hydrogen sulfide gas will be produced, with a concentration of about 1-20 g/m ³ . Hydrogen sulfide is a highly toxic and harmful gas. In the air and under humid environment conditions, hydrogen sulfide has a strong corrosive effect on pipes, burners, and other metal equipment, instruments, etc.; hydrogen sulfide combustion produces sulfur dioxide, which can directly affect human health; Strong corrosive effect. Biogas desulfurization is an indispensable treatment process in biogas production.

The methods of biogas desulfurization include chemical method, physicochemical method and biological method. At present, the desulfurization technology commonly used in China's biogas projects is mainly based on physical and chemical methods (commonly known as dry desulfurization), that is, using ferric oxide desulfurizer to remove H ₂ S in biogas. At normal temperature, biogas passes through the bed of desulfurizer, hydrogen sulfide contacts with active iron oxide to generate iron trisulfide, and then contacts with air, and the iron sulfide is converted into iron oxide and elemental sulfur. Such a desulfurization regeneration process can be cycled many times until most of the pores on the surface of the iron oxide desulfurizer are covered with sulfur or other impurities and lose their activity. The iron oxide dry desulfurization process is simple, mature and reliable, and the cost is low (the cost of a 25m ³ desulfurization tower is about 80,000), which can achieve a high degree of purification. However, the treatment cost of this method is high (about 15 yuan/kg (H ₂ S)), the operation is troublesome (the desulfurizer needs to be replaced or regenerated once every 4 to 6 months), and the waste desulfurizer has secondary pollution problems .

Compared with physical and chemical methods, biological desulfurization has the characteristics of simple equipment, low cost, environmental protection and cleanness, and recyclable elemental sulfur. It is a desulfurization technology with great development potential. Studies have shown that some microorganisms can use nitrate or nitrite as electron acceptors to oxidize sulfide to elemental sulfur. Compared with aerobic biological desulfurization, the unit waste gas treatment cost is lower. With the popularization and application of the short-cut nitrification process, using the nitrite produced by the short-cut nitrification as an electron acceptor for biogas desulfurization can further reduce the cost of waste gas treatment. Its reaction formula is:

H ₂ S+2/3NO ₂ ^- +2/3H ⁺ ——S ⁰ +1/3N ₂ +4/3H ₂ O

or H ₂ S+2/5NO ₃ ^- +2/5H ⁺ ——S ⁰ +1/3N ₂ +6/5H ₂ O

Combining biogas production with desulfurization-denitrification, a biogas bio-desulfurization-denitrification integrated device can be developed, which can not only simplify the equipment, save the biogas delivery pump, but also alleviate the effect of hydrogen sulfide on anaerobic digestion in situ. Inhibition, improve the adaptability of anaerobic reactor to sulfur-containing wastewater. the

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide an integrated device of biogas production-desulfurization-denitrification. the

Biogas production-desulfurization-denitrification integrated device includes connected biogas production area I, three-phase separation area II, desulfurization-denitrification area III and nitrification wastewater storage tank, biogas production area I includes sludge discharge pipe, water inlet pipe, reaction The bottom of the reaction cylinder is provided with a sludge discharge pipe, and the wall of the reaction cylinder is provided with a water inlet pipe, a sampling pipe and a return pipe in sequence from bottom to top; the three-phase separation zone II is provided with sewage pipes in sequence from bottom to top. Sludge settling chamber, inverted funnel-shaped three-phase separator and the first air chamber, the outer wall of the sludge settling chamber is provided with a first overflow outlet pipe, and the outer wall of the first air chamber is provided with a biogas sampling and monitoring pipe; desulfurization-denitrification The main body of Zone III includes the first desulfurization-denitrification cylinder and the second desulfurization-denitrification cylinder, and the first desulfurization-denitrification cylinder and the second desulfurization-denitrification cylinder include biogas input pipes, second overflow water outlet pipes, and second gas chambers , Purified biogas constant pressure pipe, third gas chamber, biogas collection pipe, first desulfurization-denitrification cylinder, nitrification wastewater artesian pipe, sulfur discharge pipe, second desulfurization-denitrification cylinder, disc air distributor and sludge hopper , the lower part of the first desulfurization-denitrification cylinder and the second desulfurization-denitrification cylinder are respectively equipped with a sludge hopper, and the upper part of the sludge hopper is equipped with a disc-shaped air distributor, which is connected to the biogas input pipe, and the sludge hopper The bottom end is connected with the sulfur exhaust pipe, the upper and lower ends of the purified biogas constant pressure pipe are respectively connected with the third air chamber and the second air chamber, and the nitrification wastewater artesian pipe connects the liquid in the upper and lower biogas desulfurization-denitrification cylinders, the first A biogas collecting pipe is arranged on the outer wall of the desulfurization-denitrification cylinder, and a second overflow outlet pipe is arranged on the outer wall of the second desulfurization-denitrification cylinder. the

The volume ratio of the biogas production zone I, the three-phase separation zone II and the biogas desulfurization-denitrification zone III is 2:1:1˜4:1:1. The upper end of the purified biogas constant pressure pipe is 1 to 2 cm higher than the liquid level in the first desulfurization-denitrification cylinder; 2-4cm lower than the liquid level in the second desulfurization-denitrification cylinder. The sludge hopper is conical, and the bottom angle α of the sludge hopper is 100-120°. the

Compared with the prior art, the present invention has beneficial effects: ① biogas production and desulfurization and denitrification are integrated, biogas is generated while desulfurization is performed, and no air pump is needed for transportation; ② nitrification wastewater is used as spray liquid, which can utilize nutrients in wastewater To save costs, nitrate in wastewater can also be used to avoid oxygen supply; ③ oxidize H ₂ S into elemental sulfur, which can recycle sulfur resources, and reduce nitrate to nitrogen, which can eliminate nitrogen pollution; ④ Biogas desulfurization is divided into two Stage treatment can alleviate the problem of excessive biogas pressure in biogas production units.

Description of drawings

Figure 1 is a schematic diagram of the structure of the biogas production-desulfurization-denitrification integrated device. In the figure: sludge discharge pipe 1, water inlet pipe 2, reaction cylinder 3, sampling pipe 4, return pipe 5, sludge sedimentation chamber 6, inverted funnel Three-phase separator 7, first overflow outlet pipe 8, first gas chamber 9, biogas collection monitoring pipe 10, biogas input pipe 11, second overflow outlet pipe 12, second air chamber 13, purified biogas constant pressure pipe 14, The third air chamber 15, biogas output pipe 16, first desulfurization-denitrification cylinder 17, nitrification wastewater artesian pipe 18, sulfur discharge pipe 19, second desulfurization-denitrification cylinder 20, disc air distributor 21, sludge hopper 22 and nitrification wastewater storage tank 23;

Fig. 2 is a cross-sectional view of Fig. 1A. the

Detailed ways

As shown in Figure 1, the biogas production-desulfurization-denitrification integrated device includes a connected biogas production zone I, a three-phase separation zone II, a desulfurization-denitrification zone III and a nitrification wastewater storage tank 23, and the biogas production zone I includes a waste water storage tank 23. Mud pipe 1, water inlet pipe 2, reaction cylinder 3, sampling pipe 4 and return pipe 5, mud discharge pipe 1 is provided at the bottom of reaction cylinder 3, water inlet pipe 2 and sampling pipe 4 are arranged on the wall of reaction cylinder 3 from bottom to top and return pipe 5; the three-phase separation zone II is provided with a sludge settling chamber 6, an inverted funnel-shaped three-phase separator 7 and a first air chamber 9 in sequence from bottom to top, and the outer wall of the sludge settling chamber 6 is provided with a first The overflow outlet pipe 8, the outer wall of the first air chamber 9 is provided with a biogas sampling monitoring pipe 10; the main body of the desulfurization-denitrification zone III includes a first desulfurization-denitrification cylinder 17 and a second desulfurization-denitrification cylinder 20, the first desulfurization-denitrification cylinder 20, the first desulfurization-denitrification zone III main body - Denitrification cylinder 17 and second desulfurization - Denitrification cylinder 20 includes biogas input pipe 11, second overflow outlet pipe 12, second gas chamber 13, purified biogas constant pressure pipe 14, third gas chamber 15, biogas collection pipe 16 , nitrification waste water artesian pipe 18, sulfur discharge pipe 19, disc air distributor 21 and sludge hopper 22, the first desulfurization-denitrification cylinder 17 and the lower part of the second desulfurization-denitrification cylinder 20 are respectively equipped with sludge hopper 22, The upper part of the sludge hopper 22 is provided with a disc-shaped gas distributor 21, which is connected to the biogas input pipe 11, the bottom of the sludge hopper 22 is connected to the sulfur discharge pipe 19, and the upper and lower ends of the purified biogas constant pressure pipe 14 are respectively Connected with the third gas chamber 15 and the second gas chamber 13, the nitrification wastewater artesian pipe 18 connects the liquid in the upper and lower biogas desulfurization-denitrification cylinders, and a biogas collection pipe is provided on the outer wall of the first desulfurization-denitrification cylinder 17 16. A second overflow outlet pipe 12 is provided on the outer wall of the second desulfurization-denitrification cylinder 20 . the

The volume ratio of the biogas production zone I, the three-phase separation zone II and the biogas desulfurization-denitrification zone III is 2:1:1˜4:1:1. The upper end of the purified biogas constant pressure pipe 14 is 1 to 2 cm higher than the liquid level in the first desulfurization-denitrification cylinder 17; The lower end of the waste water artesian pipe 18 is 2-4 cm lower than the liquid level in the second desulfurization-denitrification cylinder 20 . The sludge hopper 22 is conical, and the bottom angle α of the sludge hopper 22 is 100-120°. the

Five system work processes of the present invention are as follows:

(1) Biogas production system. It mainly includes mud discharge area 1, water inlet pipe 2, reaction cylinder 3, sampling pipe 4, return pipe 5, inverted funnel-shaped three-phase separator 7 and overflow outlet pipe-8. After the wastewater enters the biogas production zone I, biogas is produced by microorganisms, and the granular sludge enters the inverted funnel-shaped three-phase separator with the rising biogas and wastewater to realize the three-phase separation of gas, liquid and solid. The biogas further enters the desulfurization-denitrification device, and the effluent after treatment is discharged from the reactor through the overflow outlet pipe 8. The reflux of the fermentation broth through the reflux pipe 5 can promote the release of H ₂ S in the liquid phase.

(2) Nutrient solution distribution system. Pump the nutrient solution in the nitrification wastewater storage tank to the desulfurization-denitrification cylinder 17 through the delivery pump and delivery pipe. When the liquid level in the desulfurization-denitrification cylinder 17 is too high, the nutrient solution enters the desulfurization through the nitrification wastewater artesian pipe 18 - Denitrification cylinder 2 20, desulfurization - Denitrification cylinder 2 is provided with an overflow outlet pipe 2 12 to discharge the nitrification wastewater after denitrification from the reactor. Using nitrification wastewater from a wide range of sources as the nutrient solution and electron acceptor of desulfurization microorganisms for biogas desulfurization can not only reduce the operating cost of desulfurization equipment, but also realize waste treatment with waste. the

(3) Biological desulfurization system. The biogas containing hydrogen sulfide is transported to the disc gas distributor 21 through the biogas delivery pipe 11 under the push of its own air pressure. The biogas is released uniformly in the liquid phase through the gas distributor, and the hydrogen sulfide in the biogas enters the liquid phase through gas-liquid exchange. It is removed by microorganisms in the desulfurization-denitrification cylinder. Biogas input is similar to the aeration process in the activated sludge process. On the one hand, it can transfer a large amount of hydrogen sulfide in the gas phase into the liquid phase, and on the other hand, it can stir the activated sludge in the desulfurization-denitrification cylinder. Simultaneously treat biogas containing hydrogen sulfide and nitrification wastewater in two stages, which can alleviate the problem of excessive biogas pressure in biogas production units. The first gas chamber and the third gas chamber are respectively equipped with a biogas collection monitoring pipe 10 and a biogas output pipe 16. The desulfurization efficiency of the device can be monitored by analyzing the hydrogen sulfide content of the collected gas to ensure that the hydrogen sulfide content in the biogas is less than 20mg/m ³ .

(4) Elemental sulfur collection and discharge system. The angle α between the sloping plate of the sludge hopper 22 and the horizontal plane is 20-40°, and the density of the sulfur-containing sludge is higher than that of ordinary sludge. Under the action of gravity and biogas stirring, the sulfur-containing sludge gradually settles into the sludge hopper. The sulfur exhaust pipe 19 is discharged from the reactor to achieve the purpose of recovering elemental sulfur. the

Claims (4)

1. methane production, desulfuration and denitrification integrated device; It is characterized in that comprising the biogas production district I, three-phase separation area II, desulfurization-denitrogenation district III and the nitration waste water storage tank (23) that are connected; Biogas production district I comprises shore pipe (1), water inlet pipe (2), reaction tube (3), stopple coupon (4) and return line (5); Reaction tube (3) bottom is provided with shore pipe (1), is provided with water inlet pipe (2), stopple coupon (4) and return line (5) on reaction tube (3) wall from top to bottom successively; Three-phase separation area II is provided with sludge settling chamber (6), the triphase separator of falling the funnel-form (7) and first air chamber (9) from top to bottom successively; The outer side wall of sludge settling chamber (6) is provided with the first overflow rising pipe (8), and the outer side wall of first air chamber (9) is provided with biogas sampling monitoring pipe (10); Desulfurization-denitrogenation district III main body comprises first desulfurization-denitrogenation tube (17) and second desulfurization-denitrogenation tube (20); First desulfurization-denitrogenation the tube (17) and second desulfurization-denitrogenation tube (20) comprises biogas input tube (11), the second overflow rising pipe (12), second air chamber (13), purifying marsh gas constant voltage pipe (14), the 3rd air chamber (15), collecting methane pipe (16), nitration waste water gravity line (18), sulphur discharging pipeline (19), dish-type gas pipe (21) and sludge bucket (22); First desulfurization-denitrogenation the tube (17) and second desulfurization-denitrogenation tube (20) bottom is respectively equipped with sludge bucket (22); Sludge bucket (22) top is provided with dish-type gas pipe (21); Dish-type gas pipe (21) links to each other with biogas input tube (11); Sludge bucket (22) bottom is connected with sulphur discharging pipeline (19); The upper and lower ends of purifying marsh gas constant voltage pipe (14) is connected with second air chamber (13) with the 3rd air chamber (15) respectively; Nitration waste water gravity line (18) is two fluid connections that biogas desulfurization-denitrogenation tube is interior up and down, and first desulfurization-denitrogenation tube (17) outer side wall is provided with collecting methane pipe (16), and second desulfurization-denitrogenation tube (20) outer side wall is provided with the second overflow rising pipe (12).

2. a kind of methane production, desulfuration and denitrification integrated device according to claim 1 is characterized in that: the volume ratio of described biogas production district I, three-phase separation area II and biogas desulfurization-denitrogenation district III is 2: 1: 1～4: 1: 1.

3. a kind of methane production, desulfuration and denitrification integrated device according to claim 1 is characterized in that: described purifying marsh gas constant voltage pipe (14) upper end exceeds 1～2cm than first desulfurization-interior liquid level of denitrogenation tube (17); Nitration waste water gravity line (18) upper end flushes with first desulfurization-interior liquid level of denitrogenation tube (17), and nitration waste water gravity line (18) lower end is than the low 2～4cm of second desulfurization-interior liquid level of denitrogenation tube (20).

4. a kind of biogas production-desulfurization denitrification integrated device according to claim 1 is characterized in that: described sludge bucket (22) is taper, and the base angle of sludge bucket (22) is 100～120 °.

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