Analysis of dimethyl ether content in liquefied gas

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Ni Weidou, an academician of the Chinese Academy of Sciences, said that there are indeed problems and hidden dangers in the current application field of dimethyl ether.: First, due to the corrosion and swelling of ordinary rubber gaskets caused by dimethyl ether, merchants did not use special cylinders and special rubber seals for dimethyl ether, which easily caused safety hazards such as gas leakage. ； Second, because there is no standard for dimethyl ether blending, the blending ratio ranges from 15% to 30%, and some even exceed 30%, resulting in chaotic market order. ； Third, liquefied gas mixed with dimethyl ether has no obvious label and is sold at the same price as pure liquefied gas. However, the calorific value of dimethyl ether is only equivalent to 67% of the calorific value of liquefied gas, which harms the rights and interests of consumers. If it is allowed to develop and lead to a major vicious accident, it will completely ruin the future of dimethyl ether products and industry. Therefore, rectification is necessary. However, relevant departments should also realize that: The root cause of the above problems is precisely the lack of relevant standards. hope * * Technical specifications and safety standards for each link should be promulgated as soon as possible so that all parties involved in production, sales, use, supervision and inspection have laws to follow, and violators will be severely punished in accordance with the law. In this way, many alternative energy products, including dimethyl ether, can be well promoted, and the industry will also develop healthily. [Details] Special gas chromatograph for the analysis of dimethyl ether in liquefied gas. Welcome to view the main performance characteristics of the special gas chromatograph for the analysis of dimethyl ether in petroleum liquefied gas.: 1. The instrument adopts a full microcomputer automatic control system and an adjustable LCD display with rich and intuitive display content. ； Chinese keyboard operation makes parameter setting and operation very convenient. 2. Adopting a new dual-CPU design, original Japanese highly integrated electronic circuit technology, excellent reliability and anti-interference ability, the temperature control accuracy reaches 0.1°C, the display accuracy is as high as 0.01°C, and the power consumption percentage of each heating part can be displayed simultaneously. 3. The design of three gas paths and large-volume column chamber can install three chromatographic columns and two detectors, FID and TCD, at the same time. It can also easily expand the three detectors of ECD, FPD and NPD, as well as expand external control equipment such as gas injector and conversion furnace. 4. This machine can be easily expanded from a single FID amplifier to a dual FID amplifier, truly realizing one machine with multiple uses. 5. It is also equipped with two packed column vaporization chambers and an independent capillary dedicated system. The design of the vaporization chamber draws on the miniaturized design of similar foreign products. It has a fast heating speed and no injection dead ends. It has an excellent capillary split/splitless injector and makeup system, and can easily install small-diameter capillary columns, large-diameter capillary columns and various packed columns. 6. It has a five-order linear temperature program function, which is suitable for multi-component sample analysis. 7. The column chamber has a frequency conversion intelligent rear door automatic cooling system, which cools down very quickly (it only takes 5 minutes to drop from 280°C to 50°C, achieving true near-room temperature operation. 8. It has six independent temperature control systems. It is suitable for the installation of multiple temperature control requirements such as conversion furnaces. The column chamber, vaporization chamber, hydrogen flame detection chamber, thermal conductivity detection chamber, auxiliary 1 and auxiliary 2 all adopt modular design, making installation and replacement more convenient. 9. It has power-down protection function and can automatically memorize setting parameters. It has anti-interference function due to sudden power changes and stopwatch timing function. 10. It has over-temperature protection function. It will automatically cut off the power and alarm when the temperature exceeds the set upper limit. If the temperature of any channel exceeds the set temperature, heating will automatically stop ； And there are prompts for the cause of the failure and alarm prompts. 11. It has "0℃" protection function. When the temperature display of any channel is always "0℃", the heating will automatically stop to prevent the heating element from being damaged due to constant heating in the room. There will also be prompts for the cause of the failure and alarm prompts. 12. The first gas cutoff protection and prompt function among similar products, which can protect the TCD tungsten wire and chromatographic column from damage to the maximum extent. 13. It has a wide range of fault self-diagnosis function, 36 kinds of self-diagnosis information, and displays the fault cause and processing method at any time. 14. Stable gas circuit system: (1) The carrier gas flow adopts a dual-stability design that first stabilizes the pressure and then stabilizes the flow. ； (2) Precise air path control valves with high reproducibility and stability. 15. Multiple sampling methods are optional: (1) Packed column head injection ； (2) Packed column vaporization sampling ； (3)Capillary split/splitless injection: Back pressure valve control technology, linear diversion ； (4) Six-way valve gas injection ； (5) Automatic headspace sampling ； Temperature control index: 1) Column box: Room temperature +5℃-400℃ Accuracy: 0.1℃ display accuracy is as high as 0.01℃ 2) Sampler: Room temperature +5℃-400℃ Accuracy: 0.1℃ display accuracy is as high as 0.01℃ 3) Detector: Room temperature +5℃-400℃ Accuracy: 0.1℃ display accuracy is as high as 0.01℃ 4) Column oven volume: 248*248*260MM 5) Programmed heating steps: Fifth-order linear program rising 6) Programmed heating rate: 0.1℃~40℃ (0.1℃ increment) 7) Constant temperature holding time of each stage: 0~9999.9min (0.1min increment) Detector technical indicators: Technical plan for dimethyl ether analysis in liquefied gas 1. Brief description: Dimethyl ether is a new type of green and environmentally friendly energy. Its performance is similar to that of liquefied gas. It is a new clean fuel that can potentially replace petroleum products. It contains oxygen, has a single component, short carbon chain, good combustion performance, high thermal efficiency, no residual liquid and no black smoke during the combustion process. It is a high-quality, clean fuel. Experimental data proves that when mixed with liquefied gas at a ratio of no more than 25%, the latent substitution ratio with liquefied gas is 1: 1. The mixing ratio should be strictly controlled, and it should be 1 in autumn and winter.: 5 or 1: 6, 1 in spring and summer: 4 or 1: 3. Mixing dimethyl ether into liquefied gas can make the combustion of liquefied gas more complete, take out the residual liquid, reduce the possibility of carbon precipitation, and reduce the CO and hydrocarbon content in the exhaust gas ； In addition, dimethyl ether can also be mixed into city gas and natural gas for mixed burning, which can solve the problem of insufficient gas volume during peak periods of city gas, while improving gas quality and calorific value. Our company now recommends a method for analyzing liquefied gas, dimethyl ether, and dimethyl ether in liquefied gas. Most liquefied gases on the market are now mixed with dimethyl ether. Want to know what the percentage content of each component of liquefied petroleum gas is? Is there dimethyl ether in liquefied gas? How much dimethyl ether is there? If you want to mix dimethyl ether into liquefied gas, what is the content after mixing? What is the purity of the purchased raw material dimethyl ether? 2. Principle of the method The analysis of liquefied gas includes the analysis of liquefied gas components and the analysis of dimethyl ether and methanol in liquefied gas, excluding alkynes. A gas chromatograph with a thermal conductivity detector is used to separate each component in the sample through a chromatographic column. The area normalization method or the corrected area normalization method is used to quantify the percentage content of each component. 3. Instruments and materials 1. GC-2010 gas chromatograph (standard three-compartment host): Thermal conductivity detector (TCD) gas source: Hydrogen is used as carrier gas, hydrogen purity ≥99.99% (hydrogen generator) 2. Data processing: N2000 dual-channel chromatography workstation 3. Injector: Six-way valve, quantitative tube 1ml4. column: ￠3*6m dimethyl ether analysis column in liquefied gas 5. sampler: Sampling bag 2L6. computer: Analysis spectrum of dimethyl ether in self-prepared liquefied gas: (￠3＊6m) Attached: * * Standard liquefied gas component name chemical formula content (﹪) name chemical formula content (﹪) Methane CH4 0.01-1 Isobutene C4H8 0.01-10 Ethane C2H4 0.01-1 Trans-butene-2 C4H8 0.01-10 Ethylene C2H4 0.01-1 Male-butene-2 C4H8 0.01-10 Propane C3H8 0.01-20 1.3-Butadiene C4H6 0.01-5 Propylene C3H8 0.01-50 Isopentane C5H12 0.01-5 Isobutane C4H10 0.01-20 n-pentane C5H12 0.01-5 n-butane C4H10 0.01-20 1-Pentene C5H9 0.01-5 n-butene C4H8 0.01-10 n-hexane C6H14 0.01-2