8 results about "Excess nitrogen" patented technology

The invention belongs to the technical field of nitrogen recovery devices, and particularly relates to a recovery and liquefaction device for excess nitrogen emptied by a high-purity nitrogen device, the recovery and liquefaction device comprises a nitrogen compressor, an expansion machine, a main heat exchanger, a gas-liquid separator, a subcooler and a liquid measuring cylinder; a discharging pipeline of the nitrogen compressor is divided into a first pipeline and a second pipeline, the first pipeline penetrates through the main heat exchanger to be connected with the expansion end of the expansion machine and then penetrates through the main heat exchanger, and then the first pipeline is communicated with an emptying pipeline between the fractionating tower and the nitrogen compressor; the second pipeline is connected with the compression end of the expansion machine, then penetrates through the main heat exchanger and then penetrates through the subcooler after passing through the gas-liquid separator; a liquid nitrogen discharging pipeline of the liquid measuring cylinder penetrates through the subcooler, and the liquid measuring cylinder is supplemented with liquid nitrogen prepared by the subcooler. The device is used for solving the technical problem that a matched high-purity nitrogen production device in the current photovoltaic manufacturing process can empty part of nitrogen, and waste is caused.

The invention relates to an environment-friendly gold leaching agent and an application method of the environment-friendly gold leaching agent in arsenic-containing refractory gold ore, and belongs to the technical field of hydrometallurgy. Preparing an auxiliary mixing agent from sodium carbonate and sodium sulfate according to a molar ratio of 4: 1 to 6: 1, and reacting for 2-4 hours at 200-300 DEG C under the action of excessive nitrogen to prepare a thiocyanogen complex; and cooling and crushing to obtain thiocyanogen complex powder. The effective cyanide concentration is 3%-5%, and cyanide volatilization and environmental pollution are remarkably reduced. According to the method, under the synergistic effect of biological pre-oxidation, the gold leaching efficiency is guaranteed, meanwhile, the unit dosage of sodium cyanide is remarkably reduced, the problems that a traditional cyanide method is high in toxicity and low in recovery rate of wrapped gold in the refractory gold ore are solved, and the method has high efficiency, environmental protection property and industrial feasibility and is suitable for green gold extraction of the high-arsenic and high-sulfur gold ore.

The invention relates to the synthesis of urea from ammonia and carbon dioxide, wherein the hydrogen required for ammonia synthesis is obtained both by steam reforming of feed natural gas (grey hydrogen) and by electrolysis of water using electricity from renewable energy sources (green hydrogen). As the proportion of green hydrogen increases, the amount of carbon dioxide formed in the synthesis gas during steam reforming is no longer sufficient for the synthesis of urea. Therefore, flue gas, which is formed during the combustion of a fuel gas composed of fuel natural gas and combustion air and which also contains carbon dioxide, is additionally used. The oxygen formed during the electrolysis of water is introduced into the flue gas, and the modified flue gas is fed to a secondary reformer; and / or the fuel natural gas is combusted together with combustion air and the oxygen formed during electrolysis. Excess nitrogen is preferably separated from the synthesis gas before it is used for the synthesis of ammonia.

The present application relates to high-efficiency activated carbon utilization technical field, specifically, it relates to a kind of redundant nitrogen recovery process in high-purity oxygen production equipment.It includes the plate heat exchanger, precision filter, molecular sieve dryer, adsorption tower, vacuum pump, screw compressor, high-pressure storage tank and PLC control cabinet connected in sequence.The present application is preprocessed by plate heat exchanger using oxygen production equipment waste heat / cold quantity, and modified high-efficiency activated carbon is selectively adsorbed under normal temperature and pressure, and vacuum and waste heat gas regeneration and desorption gas back are combined, while obtaining purity≥99.99% nitrogen, energy consumption is significantly reduced and the connection with oxygen production main process is realized, and the technical problems of low recovery purity, high energy consumption and process interference are solved.

The invention relates to the synthesis of urea from ammonia and carbon dioxide, wherein the hydrogen required for the synthesis of ammonia is obtained both by steam reforming of feed natural gas (grey hydrogen) and by electrolysis of water using electricity from renewable energy (green hydrogen). As the proportion of green hydrogen increases, the amount of carbon dioxide produced in the synthesis gas during steam reforming is no longer sufficient for the synthesis of urea. Flue gas is therefore also used, which is formed during the combustion of a combustion gas from fuel natural gas and combustion air and also contains carbon dioxide. The oxygen produced during the electrolysis of water is introduced into the flue gas and fed to a secondary reformer as modified flue gas; and / or fuel natural gas is combusted together with combustion air and the oxygen produced during the electrolysis.Preferably, excess nitrogen is separated from the synthesis gas before it is used to synthesize ammonia.

Systems and methods are providing for filtering a body of water, such as a lake, ocean, river or the like. A system comprises a housing having an interior configured for containing a plurality of bivalves within the water and a fluid distribution system coupled to the housing and configured to circulate water within the interior of the housing such that the water is filtered by the bivalves at a rate of about 10 to about 100 gallons of water per day per bivalves. The system provides a controlled environment to allow bivalves, such as clams, oysters and scallops, to filter the water naturally and remove materials, such as sediment, nitrogen, phosphorus, carbon, magnesium, zinc and the like. Oysters may, for example, filter pollutants from the water, remove excess nitrogen from the water and / or remove carbon from the water, which reduces the overall amount of carbon that eventually ends up in the atmosphere.

The invention belongs to the technical field of smart agriculture, and provides a rice fertilization decision-making method based on a standard ratio vegetation index, which comprises the steps of fertilization processing, spectral data acquisition, data processing and analysis, fertilization decision-making model construction, target area rice canopy spectrum acquisition, fertilization scheme generation, fertilization decision execution and the like. On the basis of unmanned aerial vehicle remote sensing spectral data of a canopy in the whole growth period of rice, a nitrogen fertilizer nutrition diagnosis and fertilization regulation model is constructed by calculating a ratio vegetation index. The model can accurately identify canopy spectrum differences under different nitrogen fertilizer treatment in the flourishing period of rice growth, and realizes accurate diagnosis of nitrogen abundance and deficiency conditions of the overground part, thereby improving the efficiency and precision of fertilization, reducing environmental pollution caused by excessive nitrogen fertilizer application, and realizing cost saving and efficiency improvement.

The utility model provides a nitrogen supply system which comprises a pressure swing adsorption nitrogen making unit, a quenching device, a first gas conveying pipeline, a second gas conveying pipeline and a third gas conveying pipeline, external compressed air is connected with the input end of the pressure swing adsorption nitrogen making unit through the first gas conveying pipeline, and the pressure swing adsorption nitrogen making unit is used for adsorbing and discharging nitrogen in the compressed air. The output end of the pressure swing adsorption nitrogen making unit is connected with the input end of the quenching device through a second gas pipeline, the quenching device cools high-temperature nitrogen output by the pressure swing adsorption nitrogen making unit to improve the purity of the nitrogen, and the output end of the quenching device is connected with the gas supply end of the production workshop through a third gas pipeline. A nitrogen storage tank is arranged between the pressure swing adsorption nitrogen generation unit and the quenching device and is used for storing redundant nitrogen, adjusting the nitrogen amount and carrying out flow peak regulation; and a first water escape valve is arranged, accumulated water generated by gathering nitrogen in the second gas conveying pipeline is discharged, and the nitrogen purity is improved in an auxiliary mode.