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CN-122010659-A - High-efficiency ethylene preparation method

CN122010659ACN 122010659 ACN122010659 ACN 122010659ACN-122010659-A

Abstract

The invention provides a high-efficiency ethylene preparation method, and relates to the technical field of chemical synthesis. According to the method, ethephon ClCH 2 CH 2 PO(OH) 2 is used as an ethylene precursor, barium hydroxide Ba (OH) 2 is used as an alkaline reaction medium, ethylene is efficiently prepared through hydrolysis reaction at normal temperature, and high temperature and strong acid are not needed for the core reaction. The core innovation is that the technology of mild hydrolysis-directional gas production is adopted, the raw material proportion and the reaction condition are optimized, the rapid gas production within 1 minute is realized, the ethylene purity is more than or equal to 92%, the raw materials are easy to purchase and low in price, the safety is high, the byproducts can be recycled, and the pain points of high corrosion risk, high energy consumption and more byproducts in the traditional concentrated sulfuric acid dehydration method are solved. The method is simple and convenient to operate, visual in phenomenon, and capable of improving the gas production efficiency by more than 60% compared with the traditional method, reducing the cost by 50%, meeting the ethylene property verification requirement in teaching, adapting to the efficient preparation of a small experiment scene, and having obvious safety, economy and practicability.

Inventors

  • Me Shiyan
  • CUI XUEFENG

Assignees

  • 么世岩

Dates

Publication Date
20260512
Application Date
20260126

Claims (8)

  1. 1. A high-efficiency ethylene preparation method is characterized in that ethylene is prepared by hydrolysis reaction at normal temperature by taking ethephon ClCH 2 CH 2 PO(OH) 2 as an ethylene precursor and taking an alkaline compound as a reaction medium; The preparation method comprises the following steps: step one, raw material preparation Respectively taking ethephon and an alkaline compound according to the mass ratio of 1:2-1:4, wherein the ethephon is an aqueous solution with the mass fraction of 30% -50%, and the alkaline compound is barium hydroxide solid; Step two, reaction starting Adding an alkaline compound into a reaction container, slowly injecting an ethephon aqueous solution, slightly oscillating to uniformly mix materials, and starting a hydrolysis reaction at normal temperature and normal pressure; Step three, gas collection Collecting the generated ethylene gas by adopting a drainage and gas collection method, wherein the collection time is less than or equal to 5 minutes; step four, verifying target products And (3) introducing the collected ethylene gas into bromine water or acidic potassium permanganate solution, verifying ethylene through solution fading, and using the ethylene gas for subsequent experiments or application after the ethylene gas is qualified.
  2. 2. The process for producing high efficiency ethylene according to claim 1, wherein the chemical equation of the reaction in the process is: When the basic compound is barium hydroxide, the chemical equation is 6ClCH 2 CH 2 PO (OH) 2 + 12Ba (OH) 2 = 3BaCl 2 + 6CH 2 =CH 2 ↑+ 3Ba 3 (PO 4 ) 2 ↓+ 18H 2 O.
  3. 3. The method for preparing ethylene according to claim 3, wherein the byproducts generated by the reaction are barium chloride BaCl 2 and barium phosphate Ba 3 (PO 4 ) 2 , and the byproducts can be recovered for other chemical experiments after filtration and drying.
  4. 4. The process for producing ethylene according to claim 1, wherein the basic compound is a barium hydroxide solid, and no additional water is required for the reaction.
  5. 5. The method for producing ethylene according to claim 1, wherein the preferred mass ratio of ethephon to the basic compound in the first step is 1:2, and the amount of 40% by mass of the barium hydroxide solid is 10g and the amount of the barium hydroxide solid is 9.5g.
  6. 6. The method for preparing ethylene with high efficiency according to claim 1, wherein the reaction vessel in the second step is a test tube with a conduit or a branched test tube, and the ethylene aqueous solution is slowly added along the vessel wall during injection, so that severe splashing is avoided, the oscillation frequency is 5-10 times/min, and the mixing time is less than or equal to 30 seconds.
  7. 7. The method for preparing ethylene with high efficiency according to claim 1, wherein in the step three, the end of the reaction vessel conduit is inserted into water, the collecting device is kept sealed, the purity of ethylene gas is not less than 92%, and the gas production volume in a single reaction cycle is 50-150 ml.
  8. 8. The method for preparing ethylene with high efficiency according to claim 1, wherein the method is suitable for chemical teaching demonstration, ethylene property verification experiment or small laboratory temporary preparation scene, and can directly verify the chemical property of ethylene by addition reaction with bromine water, oxidation reaction with acidic potassium permanganate, and the like.

Description

High-efficiency ethylene preparation method Technical Field The invention relates to the technical field of chemical synthesis, in particular to a high-efficiency ethylene preparation method. Background Ethylene is used as an important organic chemical basic raw material and is also a core material for verifying the properties of unsaturated hydrocarbon in chemical teaching. The traditional laboratory ethylene preparation method is mainly based on an ethanol concentrated sulfuric acid dehydration method, and has a plurality of defects which are difficult to overcome: The safety risk is high, 98% concentrated sulfuric acid is used as a catalyst and a dehydrating agent, equipment corrosion and personnel burn are easy to cause due to strong corrosiveness, the reaction is heated to 170 ℃, ethanol is easy to carbonize at high temperature, and the risk of bumping and flushing is caused; The problems of energy consumption and byproducts are that the high temperature of 170 ℃ needs continuous heating, the energy consumption is large, side reactions (such as diethyl ether generation at 140 ℃) are easy to occur, the ethylene purity is low and is usually less than or equal to 80%, and the byproducts pollute the environment; the operation and cost are limited, the raw materials need high-purity ethanol and concentrated sulfuric acid, the storage condition is strict, the price is higher, the operation flow is complex, the reaction time is long, and the rapid observation in teaching demonstration is not facilitated; the teaching applicability is poor, the reaction phenomenon is not visual, black substances generated by carbonization are easy to interfere students' understanding of ethylene preparation principle, and corrosive reagents limit the development of student grouping experiments. The existing improvement method is tried to replace the catalyst, but still does not leave the dependence of high-temperature and strong corrosive reagents, or has the problems of difficult raw material purchase and low gas production efficiency. Therefore, developing a normal-temperature, safe, rapid and low-cost ethylene preparation method becomes a key for solving the demands of teaching and small-sized experimental scenes. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a high-efficiency ethylene preparation method, which solves the problems that the prior improved method is not separated from the dependence of high-temperature and strong corrosive reagents or the raw materials are not easy to purchase and the gas production efficiency is low although the catalyst is tried to be replaced. In order to achieve the above purpose, the invention is realized by the following technical scheme: a high-efficiency ethylene preparation method uses ethephon ClCH 2CH2PO(OH)2 as ethylene precursor and uses alkaline compound as reaction medium to prepare ethylene through hydrolysis reaction at normal temperature; The preparation method comprises the following steps: step one, raw material preparation Respectively taking ethephon and an alkaline compound according to the mass ratio of 1:2-1:4, wherein the ethephon is an aqueous solution with the mass fraction of 30% -50%, and the alkaline compound is barium hydroxide solid; Step two, reaction starting Adding an alkaline compound into a reaction container, slowly injecting an ethephon aqueous solution, slightly oscillating to uniformly mix materials, and starting a hydrolysis reaction at normal temperature and normal pressure; Step three, gas collection Collecting the generated ethylene gas by adopting a drainage and gas collection method, wherein the collection time is less than or equal to 5 minutes; step four, verifying target products And (3) introducing the collected ethylene gas into bromine water or acidic potassium permanganate solution, verifying ethylene through solution fading, and using the ethylene gas for subsequent experiments or application after the ethylene gas is qualified. Further, the chemical equation of the reaction in the preparation method is as follows: When the basic compound is barium hydroxide, the chemical equation is 6ClCH2CH2PO (OH)2 + 12Ba (OH)2 =3BaCl2 + 6CH2=CH2↑+ 3Ba3(PO4)2 ↓+ 18H2O. Further, the byproducts generated by the reaction are barium chloride BaCl 2 and barium phosphate Ba 3(PO4)2, and the byproducts can be recovered for other chemical experiments after being filtered and dried. Further, when the basic compound is a barium hydroxide solid, no additional water is required for the reaction. Further, in the first step, the preferred mass ratio of ethephon to alkaline compound is 1:2, and when barium hydroxide solid is selected, the mass fraction of 40% of the ethephon is 10g, and the mass fraction of the barium hydroxide solid is 9.5g. Further, in the second step, the reaction vessel is a test tube with a guide tube or a branched test tube, and is slowly added along the vessel wall when ethylene aqueous solution is inj