How To Extract Helium? How To Extract Helium?

Methods for extracting helium from natural gas:
1. Helium extraction method This method separates helium based on the difference in adsorption capacity of each component in natural gas on the surface of solid adsorbent. Limited to the adsorption capacity of the adsorbent, the adsorption method is usually suitable for refining crude helium with an impurity content of less than 1O. Pressure swing adsorption (PSA) developed in recent years belongs to this improved type.
2. How to extract helium absorption method Select a suitable absorption solvent. Under certain conditions, the remaining components in natural gas with a boiling point higher than helium can be washed and absorbed to extract helium. The absorption solvents used are liquid fluorocarbons, liquid alkanes, etc.
3. How to purify helium using the diffusion method The high thermal diffusion performance of helium can be used to concentrate and extract helium from natural gas. The diffusion element used is usually a quartz glass capillary with a tube wall thickness of 0.025-0.127mm, an inner diameter to wall thickness ratio of 3-7, and an operating temperature of 400-500. The operating pressure can be selected in the range of tens of megapascals to hundreds of megapascals according to the specific operating conditions. The purity of helium extracted by diffusion of quartz glass capillary is quite high, but the quartz glass capillary used is extremely thin and inconvenient to make. It needs to be operated under a differential pressure that is quite high compared to high temperature. Therefore, the diffusion method has many limitations on the scale of helium.
4. How to extract helium. Membrane permeation method With the development of membrane materials, membrane permeation method for extracting helium shows better and better application prospects. Each gas has a certain permeability to the membrane, and the permeability of each gas is different. Therefore, permeation method can be used to extract helium from natural gas. In order to ensure the output and reduce the required membrane area, the permeation membrane used in industry has a large permeability constant, a large separation coefficient, a simplified process, and long-term performance. The selectivity of membrane materials for the permeation of various components of natural gas can be expressed by the separation factor port.
5. How to purify helium by low-temperature condensation method This method is currently widely used in various countries to extract helium from natural gas. How to purify helium. The method of extracting helium usually consists of gas source pretreatment purification, crude helium extraction and helium refining.
(1) Purify HS and CO in the helium-containing gas source by pre-treating the helium-containing natural gas. Impurities such as moisture and even mercury must be purified before entering the cryogenic device to avoid process conditions that cause clogging, corrosion and deterioration of pipelines, valves and equipment at low temperatures. The acid gas removal methods commonly used as methods for extracting helium are the alcohol amine method, hot potassium alkali method and sulfonamide method. The helium extraction process is carried out on H2S and CO in natural gas. The residual requirements are: H2s≤4ppm〔1ppm-M/22.4 (mg/m.), M is the molecular weight, the same below〕, CO≤100ppm. Considering the helium lifting effect, the removal method that is conducive to reducing the helium lifting cost should be preferred. How to extract helium Dehydration method: Natural gas helium extraction generally chooses molecular sieves for fine dehydration, and the dehydration depth is required to be less than 1ppm, and further adsorbs and removes residual acid gases. Demercuration process method: HgSIV demercuration molecular sieve can be regenerated and recycled, but the equipment and control are complex, while sulfur-impregnated activated carbon cannot be recycled and needs to be replaced regularly, but the equipment and operation are simple.
(2) How to purify helium to extract crude helium. Natural gas is subjected to secondary condensation to obtain crude helium with a helium content of 60-70%. The cooling required for condensation is supplied by atmospheric pressure liquid methane, atmospheric pressure liquid nitrogen or negative pressure liquid methane. The first condensation requires a fraction above ethane, and the second condensation requires a methane content of less than 1. At the same time, the helium content in the kettle liquid hydrocarbon is less than 10ppm, which improves the helium recovery rate.
(3) Helium refining The hydrogen in natural gas that is difficult to liquefy is concentrated into the crude helium as the helium is concentrated, and needs to be removed before refining. How to extract helium. The method of extracting helium is generally catalytic oxidation dehydrogenation in industry, and dehydrogenation technologies such as hydrogen storage alloys are also under development. Residual hydrogen below 10ppm is removed simultaneously with other impurities such as nitrogen and a small amount of methane in the subsequent high-pressure condensation adsorption process. The cold source is generally supplied by atmospheric pressure liquid nitrogen, and helium with a purity of more than 99.99% can be obtained. In other refining methods such as the washing absorption method in the helium extraction method, natural gas components such as methane and propane can be used as absorbents.
The following are 4 methods for helium purification:
1. How to extract helium by condensation method: The extraction of helium from natural gas adopts the condensation method in industry. This helium extraction method includes natural gas pretreatment and purification, crude helium extraction and helium purification, etc., to produce 99.99% pure helium. How to extract helium by condensation method is simple?
2. How to purify helium by air separation method: Generally, the method of extracting helium by fractionation method is used to extract crude helium and neon mixed gas from the air device, and separate and purify pure helium and neon mixed gas from the crude helium and neon mixed gas to obtain 99.99% pure helium.
3. How to extract helium by hydrogen liquefaction method: The hydrogen liquefaction method is used in industry to extract helium from synthetic ammonia tail gas. The helium extraction method is low-temperature adsorption nitrogen removal, distillation crude helium plus oxygen catalyst hydrogen removal and helium purification to obtain 99.99% pure helium.
4. How to purify helium: High-purity helium method: Use activated carbon to further adsorb and purify 99.99% pure helium to obtain 99.9999% high-purity helium.