50 results about "Methane yield" patented technology

A method for predicting CH4 production and CO2 sequestration in a CO2-ECBM process belongs to the field of natural hydrogen resource exploration, and is technically characterized by comprising the following steps: constructing a multiphase and multicomponent coupling model for describing the migration process of water, methane and carbon dioxide of a stratum coal bed gas reservoir; the method comprises the following steps: constructing a geologic model of a stratum coalbed methane reservoir, performing grid division on the geologic model to obtain a plurality of grid units reflecting different spatial distribution positions of the coalbed methane reservoir, and setting initial conditions and boundary conditions of the geologic model; and according to the multiphase and multicomponent coupling model, solving spatio-temporal evolution characteristics of pressure and concentration of water, methane and carbon dioxide of each grid unit of the geologic model to obtain distribution in time and space. According to the method, the influence of the underground water in the coal bed gas on the migration behavior of methane and carbon dioxide is fully considered, the limitation of prediction result deviation caused by neglecting the effect of the underground water in the existing research is overcome, and the accurate prediction of the methane yield and the carbon sequestration amount in the CO2-ECBM process is realized.

The invention belongs to the technical field of CO2 catalytic conversion, and discloses an in-situ reduction efficient CO2 methanation catalyst as well as a preparation method and application thereof. The efficient CO2 methanation catalyst NiA (CO3) xRe is formed by in-situ reduction of Ni and A coupled carbonate NiA (CO3) x, wherein A is selected from one of Mg, Ce and Al. NiA (CO3) xRe is prepared by a coprecipitation method. According to the present invention, the reaction equilibrium conversion is achieved at 300 DEG C in the reaction atmosphere with the CO2: H2: N2 volume ratio of 1: 4: 5 and the air speed of 150000 mL.gcat <-1 >. H <-1 >, the methane selectivity reaches 100%, the methane yield reaches 677.8 mmol.gcat <-1 >. H <-1 >, and the methane selectivity is still not reduced after the operation is performed for 100 h under the condition; compared with the prior art, the prepared catalyst greatly improves the high efficiency and stability of methanation catalytic reaction, the preparation process is simple, large-scale production is easy to achieve, the catalyst is matched with the temperature of coal-fired flue gas, energy does not need to be input again, efficient conversion can be completed, carbon emission is effectively reduced, and high-value products are obtained for use; and a favorable way is provided for realizing a carbon neutralization target.

The invention discloses a CSTR-based three-dimensional electrode MEC-fluidized bed reactor for anaerobic fermentation of cow dung and application, and belongs to the technical field of microbial electrochemistry. The reactor comprises a reactor main body, a feed port, a discharge port, a gas outlet and a stirring device, an anode and a cathode are arranged in the reactor main body, a conductive three-dimensional particle electrode filler is filled between the anode and the cathode to form a three-dimensional electrode system, and the anode and the cathode are connected with an external power supply. The three-dimensional electrode system is constructed, so that the reaction specific surface area and the electron transfer efficiency are greatly increased, the stimulation effect of a low-voltage electric field is amplified to the whole reaction space, and the technical bottlenecks of low mass transfer efficiency, low methane yield, easiness in system instability and the like in the traditional cow dung anaerobic digestion are solved. Compared with the traditional anaerobic digestion and two-dimensional microbial electrolysis cell, the two-dimensional microbial electrolysis cell disclosed by the invention can obviously improve the methane yield and the system operation stability, and has an excellent engineering application prospect.

This invention discloses an anaerobic bio-fermentation process for the targeted degradation of municipal sewage sludge, belonging to the field of sludge treatment technology. The process includes: pretreatment and targeted activation of components; staged hydrolysis and acidification for targeted production of short-chain fatty acids; methanogenic fermentation mediated by conductive materials coupled with a microbial electrolysis cell for assistance; multi-parameter dynamic control based on online monitoring and intelligent algorithms; magnetic separation, recovery, and recycling of magnetic conductive materials; in-situ biogas purification and product gradient reflux; solid-liquid separation and residue resource utilization. This invention achieves kinetic matching and metabolic enhancement of hydrolysis and acidification and methanogenesis through the deep linkage of four modules: targeted hydrolysis and acidification, enhanced direct interspecies electron transfer via a microbial electrolysis cell, magnetic material circulation, and intelligent control. Compared with existing technologies, the methane yield is increased by more than 40%, propionic acid accumulation is below 50 mg / L, the fermentation cycle is shortened to 8-10 days, and system energy consumption is reduced by 20%.

The invention belongs to the technical field of organic waste treatment, and particularly relates to a multi-parameter regulation and control high-cellulose organic waste anaerobic digestion treatment method. According to the method provided by the invention, high-cellulose wastes such as traditional Chinese medicine residues, olive residues and vinasse are subjected to alkali liquor, hydrothermal or biogas slurry pretreatment, the contents of reducing sugar, volatile fatty acid (mainly acetic acid) and ammonia nitrogen are synchronously monitored, and the pretreatment conditions are dynamically adjusted according to preset thresholds (the reducing sugar is less than or equal to 50mg / g, the acetic acid is obviously higher than propionic acid, and the ammonia nitrogen is less than or equal to 7mg / g). The method disclosed by the invention realizes cooperative regulation and control of hydrolysis promotion and digestion stability, effectively avoids acidification and ammonia inhibition, improves the methane yield and the system operation stability, and is suitable for efficient anaerobic digestion treatment of various high-cellulose organic wastes.

The invention belongs to the technical field of yield increase of methane gas by anaerobic degradation of lignite, and provides a method for producing methane gas by anaerobic degradation of lignite by mixing exogenous bacteria and straws. According to the method, temple river coal seam water enrichment culture flora is used as exogenous bacteria, Inner Mongolia Shengli lignite is used as a gas production substrate, the same culture medium and bacterial liquid are added, and the influence of coal, straw and addition of the coal and the straw on the methane gas production rate is analyzed. After two months of monitoring, the net methane yield of a straw and coal (1: 1) group is 84.28 mL, and the net methane yield is 28.09 mL / g; the net methane yield of a coal group is 33.15 mL, and the net methane yield is 11.05 mL / g; the gas production rate of the straw and the coal as the substrate is more than two times that of the single coal as the substrate. According to data calculation of bottled experiments, the daily gas production rate of the exogenous bacteria for degrading the coal and the straws is 0.47 m < 3 > / t / d. The exogenous bacteria and the straws jointly act on the lignite, so that the gas volume and the gas production rate are obviously increased. And the generated methane can also be used as a green energy source in other fields.

The invention provides a method for preparing methane through pyrolysis of medical waste and application of the method, and relates to the technical field of medical waste treatment and energy recovery, and the method comprises the following steps: pyrolyzing the medical waste to obtain pyrolysis gas, purifying the pyrolysis gas, then carrying out steam reforming reaction to obtain reacted gas, separating and purifying the reacted gas to obtain the methane. Methane is obtained; during pyrolysis, the temperature is increased to 190 DEG C to 210 DEG C and kept for 8 min to 12 min, then the temperature is increased to 390 DEG C to 410 DEG C and kept for 13 min to 17 min, and then the temperature is increased to 540 DEG C to 560 DEG C and kept for 30 min to 40 min; the steam reforming reaction catalyst is a lanthanum modified nickel-based catalyst. According to the method, the technical effects of destroying pathogens in the medical wastes, cracking macromolecular organic matters, improving the methane yield and purity and reducing the treatment cost are achieved, and harmless, resourceful and efficient treatment of the medical wastes is realized.

The invention discloses a method for promoting anaerobic digestion of sludge to produce methane through combination of straw bacterial saccharification products and sludge pretreatment, and belongs to the field of preparation of methane from waste biomass by microorganisms. The invention aims to solve the problems of low hydrolysis rate and low methane yield in the conventional process for producing methane by anaerobic digestion of sludge. The method comprises the following steps: 1, taking crushed corn straws as a saccharification substrate, and inoculating R.thermocell M3 to prepare a saccharification product; 2, adjusting the pH value of the residual sludge in the secondary sedimentation tank to 9; and 3, carrying out anaerobic digestion on the microbial saccharification product and sludge to produce methane. In the anaerobic digestion system, the methane production process of the sludge is enhanced by pretreating the sludge and adding the microbial saccharification product containing the high-carbon compound, so that the methane yield is increased.

The invention discloses a silage data processing device, method and computer program for predicting rumen digestion gas production. Based on silage properties (13 input variables) and rumen gas production and digestion results (14 output variables at different moments), a model for predicting the gas production and digestion results of the silage in the rumen is constructed by using five tree models such as CatBoost and the like. R2 of the total gas production rate prediction model and R2 of the methane yield prediction model can be higher than 0.83, and the highest R2 can reach 0.96; the R2 of the digestibility model is more than 0.79, except for the IVDMD24h model (0.58), the data processing device and method can be applied to precise feeding and green breeding of ruminants.

The application discloses an anaerobic treatment system and process suitable for wastewater containing high organic suspended matter, which comprises a water inlet assembly, a reactor, an internal circulation assembly, a water collecting and discharging assembly and an exhaust assembly; a group of metal membrane tubes are arranged in the reactor, and hydrolytic acid-producing bacteria are loaded in the metal membrane tubes; methanogenic bacteria are filled in the space outside the metal membrane tubes in the reactor; the reactor is connected with the water inlet assembly through the bottom of the metal membrane tubes; the internal circulation assembly is connected with the upper and lower parts of the reactor respectively; the water collecting and discharging assembly is arranged on the top of the reactor, and the reaction water is discharged from the reactor through a discharging pipeline; and the exhaust assembly is connected with the top of the reactor. The application can realize the effect that the acid-producing phase and the methanogenic phase are separated from each other and cooperate with each other, the effluent water is filtered through a membrane, and stable three-phase separation is realized. The application has the advantages of high anaerobic reaction efficiency, stable effluent water quality and high methane yield, and is especially suitable for anaerobic treatment of wastewater containing high organic suspended matter.

The invention discloses a method and a device for producing low-carbon olefin by catalytic cracking of heavy hydrocarbon, which can produce high-yield low-carbon olefin and carbon raw materials at the same time, improve the yield and selectivity of ethylene, propylene and butylene, reduce the yield of methane, reduce the alcohol content in the product to the greatest extent, and realize conversion of low-cost alcohol into low-carbon olefin. The method can realize high-selectivity conversion of olefin and alcohol into low-carbon olefin, solves the problem of overhigh yield of methanol cracking methane, maximally obtains ethylene and propylene, improves the selectivity of methane and coke, and realizes high-efficiency utilization of alcohol and fossil resources.

This invention discloses a catalyst for the production of ethylene and propylene, its preparation method, and its applications. The catalyst comprises the following components: I) 1%–10% of chemical formula A x B y D z A compound of O4; in the chemical formula, the oxidation states of elements A, B, and D are m, n, and p, respectively, satisfying x·m + y·n + z·p = 8, where m, n, and p are integers not greater than 3; the A x B y D z O4 has a spinel structure; II) 0.5%–10% is selected from at least one oxide of rare earth elements, P, Mo, and W; III) 20.0%–55.0% is selected from at least one zeolite of ZSM-5 and ZSM-11; IV) 10%–30% is a binder; V) 25.0%–60.0% is clay. This catalyst is used in the catalytic cracking of petroleum hydrocarbons to produce ethylene and propylene, and features good catalyst stability, low methane yield, and high ethylene and propylene yields.

The invention discloses a method and a device for preparing low-carbon olefin, which can realize high-selectivity conversion of olefin and methanol into low-carbon olefin, solve the problem of overhigh yield of methanol cracking methane, furthest obtain ethylene and propylene, improve the selectivity of methane and coke and realize efficient utilization of methanol and fossil resources.

The invention discloses a strain combination, a methane fermentation system and a preparation method, and belongs to the technical field of microorganisms. In the methane fermentation system provided by the invention, lignocellulose in crop straws is firstly and preliminarily hydrolyzed into soluble saccharides by natural hydrolytic flora in an inoculum, and then the soluble saccharides are fermented by lactobacillus plantarum to generate intermediate products such as lactic acid, acetic acid, ethanol, hydrogen, carbon dioxide and the like; further, intermediate products such as lactic acid and ethanol are converted into methane-producing precursors such as hydrogen and acetic acid through natural microbial flora in the inoculum; subsequently, in the methane production stage, methanosarcina utilizes hydrogen and carbon dioxide to produce methane in a hydrogen nutrition mode, utilizes acetic acid to produce methane in an acetic acid nutrition mode and / or utilizes methyl substances to produce methane in a methyl nutrition mode, accumulation of intermediate products is avoided, and the conversion efficiency of a substrate and the methane yield are improved.

This invention discloses a piezoelectric biohybrid, belonging to the field of wastewater treatment and resource utilization technology. The piezoelectric biohybrid is composed of barium titanate particles and anaerobic sludge, with the barium titanate particles exhibiting piezoelectricity. This invention innovatively utilizes the abundant mechanical stress generated by fluid flow, mechanical stirring, and microbial gas production in the anaerobic fermentation system. The piezoelectric biohybrid provided by this invention converts the mechanical energy of this stress into a built-in electric field within the anaerobic fermentation system, providing a new method for driving interspecies electron transfer. This effectively enhances interspecies electron transfer between acid-producing bacteria and methanogenic bacteria, increasing methane yield under anaerobic fermentation. Furthermore, the piezoelectric biohybrid provided by this invention has the advantages of simple structure, reasonable design, and ease of manufacture.

The invention discloses a heavy hydrocarbon catalytic cracking method and a heavy hydrocarbon catalytic cracking device, which are used for producing a carbon material raw material while increasing the yield of low-carbon olefin, improving the yield and selectivity of ethylene, propylene and butylene, reducing the yield of methane, reducing the content of ethanol in the product to the greatest extent and realizing low-cost conversion of ethanol into low-carbon olefin. The method can realize high-selectivity conversion of olefin and ethanol into low-carbon olefin, solves the problem of overhigh yield of ethanol cracking methane, maximally obtains ethylene and propylene, improves the selectivity of methane and coke, and realizes efficient utilization of ethanol and fossil resources.

This invention discloses a method for improving methane yield from anaerobic fermentation of rice straw using potassium-enriched biochar. The method includes the following steps: rice straw is alkalized, then anaerobic activated sludge and potassium-enriched biochar are added, followed by sealed fermentation. The mass ratio of rice straw, anaerobic activated sludge, and potassium-enriched biochar is 20:(10-30):(1-2). This invention uses rice straw as a fermentation substrate and enhances the methane production capacity through anaerobic fermentation with the aid of potassium-enriched biochar. By adding potassium-enriched biochar to pretreated rice straw for anaerobic fermentation, this invention not only stimulates microbial activity and promotes the metabolism of system microorganisms, improving the efficiency of each stage of anaerobic fermentation, but also allows for more effective utilization of the substrate, thereby increasing methane yield.

The invention provides a catalyst for reinforcing methane recovery in a sludge anaerobic treatment process, a preparation method of the catalyst and a methane recovery method. The heterogeneous high-efficiency catalyst S-FeWO4 is synthesized by adopting a hydrothermal method in combination with annealing. The invention provides a method for strengthening methane recovery in a sludge anaerobic treatment process, which comprises the following steps: carrying out concentration treatment on residual sludge from a sewage plant, adding a catalyst S-FeWO4 prepared by the method, uniformly stirring, and adding H2O2 to obtain a mixture; anaerobic inoculation sludge is added into the mixture for anaerobic digestion, and methane is obtained. According to the method, the S-FeWO4 catalyst is prepared through sulfur-doped ferrous tungstate, so that the Fenton-like reaction performance of the iron-based catalyst is remarkably improved, H2O2 decomposition is accelerated to generate hydroxyl free radicals, the synergistic effect of the S-FeWO4 catalyst and H2O2 for promoting methane recovery is optimized, and the yield of methane in the anaerobic process is increased.

This invention discloses a method for improving methanogenesis from lignocellulose based on a mixed-culture fermentation strategy, belonging to the field of anaerobic fermentation technology. The method includes the following steps: (1) inoculating activated *Trichoderma echinosporum* into a culture medium containing lignocellulose and loofah sponge as a biological carrier material for fermentation to obtain a fermentation broth; (2) activating activated sludge using a revitalizing solution; (3) inoculating the activated sludge from step (2) into the fermentation broth of *Trichoderma echinosporum* from step (1) for anaerobic fermentation to produce methanogens. This method achieves a methane yield of 262 mL / g VS, which is more than 30% higher than that of traditional anaerobic fermentation for methanogenesis, and is of great significance for improving the bioconversion of lignocellulose resources.

This invention discloses a biochar-mediated anaerobic fermentation and recycling device for poultry manure, belonging to the field of green biotechnology. It includes a pretreatment unit, an anaerobic treatment unit, and a post-treatment unit, with the anaerobic treatment unit comprising an anaerobic treatment tank. This invention utilizes an alternating magnetic field and iron powder to synergistically break down barriers, efficiently removing suspended particles, inorganic salt crystals, and other impurities from the pores of the biochar. This avoids pore blockage and attenuation of conductive adsorption functions, effectively increasing the number of times the biochar and microbial complex can be recycled, significantly reducing treatment costs. Simultaneously, the graphitized conductive structure of the biochar forms an efficient electron transfer channel with the aggregated bacterial community, and the iron powder acts as an additional electron donor to amplify the bio-enhancing effect. An alternating electric field provides an additional micro-potential difference, further driving the electron exchange rate, ultimately increasing the methane yield compared to traditional anaerobic fermentation, thus adapting to the high ammonia nitrogen characteristics of poultry manure.

The utility model relates to a system for relieving ammonia inhibition in anaerobic digestion of medium-high temperature kitchen waste, and relates to a system for relieving ammonia inhibition in anaerobic digestion of medium-high temperature kitchen waste. The utility model is to solve the technical problems of low methane yield, high cost and ammonia nitrogen accumulation in the anaerobic digestion process of kitchen waste. The utility model draws negative pressure at the top of the anaerobic digestion tank, has low energy consumption, and can effectively reduce the ammonia nitrogen concentration of the liquid phase part and relieve the inhibition of methanogens. In addition, a small amount of H2 exists in biogas, which can generate methane under the action of hydrogen-utilizing methanogens after being recycled back to the anaerobic digestion tank, thereby increasing the proportion of methane in biogas. The utility model reduces the ammonia nitrogen partial pressure of the gas part in the anaerobic digestion tank, relieves ammonia inhibition in the system, and simultaneously realizes resource recycling, biogas purification and efficiency improvement of biogas production, thereby providing new technical support for improving the medium-high temperature anaerobic digestion of high-protein materials represented by kitchen waste.

The application discloses a kind of based on reinforcement learning's anaerobic digestion process methane production rate extreme value search method and system, it is related to anaerobic digestion process intelligent control technical field.For the existing extreme value search scheme cannot simultaneously consider optimization steady-state accuracy and convergence speed, classical algorithm exists fixed amplitude disturbance and causes steady-state oscillation, improved no steady-state oscillation scheme exists integrator gain fixed, slow convergence problem, the application constructs extreme value search control framework, realizes sine disturbance signal amplitude adaptive update by exponential decay module, introduces DDPG deep reinforcement learning algorithm, defines adaptive state, action and multi-objective reward function, realizes the online adaptive optimization of integrator gain, completes methane production rate extreme value search closed-loop control.The application can eliminate steady-state oscillation, improve optimization convergence speed simultaneously, significantly improve anaerobic digestion process running efficiency.

The present application relates to the field of sludge resource utilization, in particular to the technical field of sludge resource treatment method under low-carbon mode, more specifically to a method for improving the anaerobic digestion efficiency of residual sludge under low-carbon mode. The residual sludge is pretreated by calcium hypochlorite combined with low-temperature hydrolysis, which can significantly improve the anaerobic digestion efficiency. According to the calculation, the anaerobic digestion soluble COD of the treated residual sludge is 11.20 times higher than that of the blank group, the cumulative methane yield is increased by 163.9%, and the maximum methane production rate is increased by 158.8%. The daily methane production is increased by 57.9% compared with the blank group. The unit methane carbon emission is reduced by 45.6% compared with the blank group.

The invention provides a method for improving biogas fermentation efficiency, and belongs to the technical field of microbial anaerobic fermentation and waste resource utilization. According to the method disclosed by the invention, the crushed biomass raw material is treated by adopting a microwave-assisted hydrolysis technology, so that the hydrolysis efficiency of the biomass raw material can be remarkably improved. Besides, according to the method, microwave-assisted treatment is carried out in the anaerobic fermentation process, the metabolic activity of microorganisms in the activated sludge can be effectively stimulated, substrate decomposition and conversion of intermediate products are accelerated, and therefore the methane yield is greatly increased. Experimental data show that after microwave-assisted treatment is carried out in the anaerobic fermentation process, the yield of methane in biogas can be increased by 18% to 300%, meanwhile, the volatile solid conversion efficiency of raw materials is optimized, and the bottleneck problem of low mass transfer efficiency in a high-solid-content fermentation system is effectively solved.

The invention relates to a kitchen waste anaerobic digestion treatment method and system based on big data evaluation. The method comprises the following steps: respectively establishing kitchen waste anaerobic digestion treatment facilities without exogenous additives and kitchen waste anaerobic digestion treatment facilities with exogenous additives; state data of the kitchen waste are collected respectively; calculating the unit feeding VS biogas yield according to the biogas yield, the daily feeding amount of the kitchen waste, the feeding water content and the feeding VSin content, and calculating the methane yield by combining with the methane content; according to the consumption and methane yield under the anaerobic digestion treatment conditions without the exogenous additives and under the anaerobic digestion treatment conditions with the exogenous additives, evaluating kitchen waste anaerobic digestion treatment measures whether the exogenous additives are added or not, and determining a final treatment mode. Compared with the prior art, the kitchen waste anaerobic digestion treatment method based on big data is established, prediction of the unit feeding VS biogas yield and the methane yield is combined, and the subsequent cost analysis and comparison process can visually and objectively judge the kitchen waste anaerobic digestion treatment mode.

The application discloses a method for enhancing the methanogenic efficiency of sludge anaerobic digestion by using an iron-based MOF, wherein conductive materials of 0, 100, 150 and 200 mg / g VS are added to a residual sludge system, and anaerobic digestion is carried out at a temperature of 37±1 DEG C and an initial pH of 7.0 for 30 days. The application first applies MIL-88A(Fe) to a residual sludge anaerobic digestion system, and MIL-88A(Fe) enhances the hydrolysis rate of organic matter and the methane production rate in the anaerobic digestion system. MIL-88A(Fe) mediates the DIET pathway by promoting the secretion of cytochrome C and the production of conductive pili in the anaerobic digestion system, thereby enhancing the electron transport capacity between microorganisms in the system. The application can improve the methane production, alleviate the accumulation and inhibition of volatile fatty acids, promote the acid production rate and the intracellular and extracellular electron transport rate in the anaerobic digestion process, enhance the in-situ conversion of CO2 in the anaerobic digestion system, improve the methane production rate, and provide a new idea for efficient resource utilization of residual sludge produced by a sewage biological treatment process and solid organic waste.

The invention discloses a method for relieving an ammonia inhibition effect in a nitrogen-rich organic waste anaerobic digestion process and increasing methane yield based on microbial stress regulation. The method comprises the following steps that an active oxygen scavenger solution is added into an anaerobic reactor for producing methane, the ammonia inhibition effect is recovered, the methane yield is increased, and the active oxygen scavenger is selected from one or more of superoxide dismutase, catalase and vitamin C. According to the method, the active oxygen scavenger solution is precisely added into the fermentation system, so that the active oxygen scavenger solution plays a role in the intracellular or extracellular environment of the microorganisms, the microorganisms can still keep high metabolic activity in the high-ammonia-nitrogen environment, finally, the ammonia inhibition phenomenon is substantially recovered, and the methane yield of the system is remarkably recovered and increased.

This invention relates to a method for the catalytic hydrogenation of lignin to produce methane, belonging to the field of biomass catalytic conversion and renewable energy utilization technology. The method uses CeZrOx / Ni as a catalyst to produce methane through the catalytic hydrogenation of lignin under a hydrogen atmosphere and solvent-free conditions. First, a catalyst is prepared using nickel nitrate, zirconium nitrate, and cerium nitrate as raw materials, and oxalic acid and ethanol as excipients, through precipitation, calcination, and hydrogen reduction. Next, the catalyst and lignin are added to a reactor for catalytic hydrogenation. During the reaction, lignin first liquefies and forms a liquid phase. Under the action of the catalyst, the carbon-oxygen bonds and carbon-carbon bonds in the lignin structure break, and methane is generated through hydrogenolysis and hydrogenation. Compared with other biomass-to-methane methods, this method has no external solvent, is simple in process, has a high lignin conversion rate, and a high methane yield.

The utility model relates to the technical field of experimental instruments, and particularly discloses a filling device for a permeation tube in the process of measuring methane yield of ruminants by a sulfur hexafluoride tracer method, which comprises a box body, round holes are formed in the surface of the box body, an opening is formed in the top surface of the box body, a stainless steel plate is welded at the bottom end of the box body, and a plurality of through holes are formed in the stainless steel plate. The box body is in an L shape, the height of the opening is 85 mm, the width of the opening is equal to that of the box body, the opening is 45 mm higher than the top of the round hole, a layer of stainless steel plate is welded to the bottom of the box body to form a crack, and the thickness of the crack is 5 mm. Further, heat of the experiment table top can be effectively isolated from being conducted to liquid nitrogen, the loss speed of the liquid nitrogen is reduced, the experiment table top is protected against low-temperature damage, the safety of the experiment environment is improved, the service life of the table top is prolonged, meanwhile, it is guaranteed that the permeation pipe is stably inserted, and toppling or slipping is avoided; the method is suitable for liquid nitrogen low-temperature operation environments.