How to make ethylene, the chemical equation for preparing ethylene

In the laboratory, alcohol and concentrated sulfuric acid are mixed at 1:3 and quickly heated to 170 to decompose the alcohol. Concentrated sulfuric acid acts as a catalyst and dehydrator in the reaction process.

The reaction to make ethylene belongs to the liquid-liquid heating type.

Ethylene can cause acidic KMno4 solutions to fade quickly, which is the result of the oxidation of ethylene by potassium permanganate, while alkanes such as methane do not have this property.

Chemical properties of ethylene – addition reaction.

When ethylene is poured into a test tube containing bromine water, the reddish-brown color of the bromine water can be observed to disappear quickly. Ethylene reacts with bromine in bromine water to form a colorless liquid of 1,2-dibromoethane (CH2BR CH2BR). The essence of this reaction is that one of the double bonds in the ethylene molecule is easy to break, and two bromine atoms are added to two carbon atoms with unsaturated valence bonds to form dibromoethane.

This reaction in which the unsaturated carbon atoms in the organic molecule directly combine with other atoms or clusters of atoms to form other substances is called an addition reaction.

Ethylene can also react with hydrogen, chlorine, hydrogen halide and water under suitable reaction conditions.

Ethanol for laboratory vinyl production.

Catalytic dehydration to produce ethylene.

The chemical equation is:

CH3CH2OH — concentrated sulfuric acid.

170°c —ch 2 =ch 2 +h 2 o<>

Under the catalytic action of concentrated sulfuric acid, ethanol is used in the laboratory to produce ethylene when heated to 170. Equation: CH3CH2OH - concentrated sulfuric acid, 170 )-CH2 = CH2 + H2O

Ethylene is produced by ethanol heated to 170 degrees under the catalysis of concentrated sulfuric acid, and the elimination reaction occurs.

Preparation method of ethylene: reaction equation: C2H5OH = concentrated sulfuric acid = CH2CH2 + H2O.

Materials required for the experiment] ethanol, concentrated sulfuric acid, alcohol lamp, iron frame, broken porcelain pieces, bromine water.

Problems that need to be paid attention to in the process of producing ethylene in the laboratory:

1.Concentrated H2SO4 acts as a catalyst and dehydrating agent, and zeolite or crushed porcelain chips act as a catalyst and dehydrator.

2.The concentrated H2SO4 was mixed with ethanol according to the volume ratio of 3 1, and the reason for the excess of concentrated H2SO4 was to promote the reaction to the direction of the positive reaction.

3.The temperature should rise rapidly to 170 to prevent the formation of by-product ether at 140. This reaction is a substitution reaction rather than a elimination reaction.

4.The reason why the coding reaction solution turns black when making ethylene is that the ethanol has a redox reaction with concentrated H2SO4, so the ethylene prepared in the laboratory may also be mixed with impurity gases such as CO2 and SO2.

Ethylene preparation is an industrial method: the ethylene used in industry is mainly separated from the gas produced by petroleum refining plants and petrochemical plants. Laboratory Method:

In the laboratory is to put alcohol andConcentrated sulfuric acid is a few stoolsMix 1:3 and heat quickly to 170 to make the alcohol decompose. Concentrated sulfuric acid acts as a catalyst and dehydrator in the reaction process.

Ethylene is a synthetic fiber, synthetic rubber, synthetic plastic (polyethylene and polyvinyl chloride.

Synthesis of ethanol. alcohol) is also used in the manufacture of vinyl chloride, styrene, ethylene oxide, acetic acid.

Acetaldehyde and explosives, among others, can also be used as ripening agents for fruits and vegetables, and is a proven plant hormone.

Main uses of ethylene:

1. Ethylene is an important basic raw material for organic chemicals, mainly used in the production of polyethylene, ethylene propylene rubber, polyvinyl chloride, etc.

2. One of the most basic raw materials of petrochemical industry. In terms of synthetic materials, the bulk is used in the production of polyethylene, vinyl chloride and polyvinyl chloride, ethylbenzene, styrene and polystyrene.

and ethylene propylene rubber, etc.

In terms of organic synthesis, Biyuan is widely used in the synthesis of ethanol, ethylene oxide and ethylene glycol.

acetaldehyde, acetic acid, propionaldehyde, propionic acid and its derivatives and other basic organic synthesis raw materials; After halogenation, it can be used to produce chlorinated ethylene, chloroethane and bromoethane; It can be made into olefins by oligomerization.

And then produce higher alcohols, alkylbenzene, etc.

3. It is mainly used as the standard gas for analytical instruments in petrochemical enterprises.

4. Ethylene is used as an environmentally friendly ripening gas for navel oranges, tangerines, bananas and other fruits.

5. Ethylene is used in pharmaceutical synthesis and high-tech material synthesis.

Produced by oil separation:

Ethylene is formed by petrochemical cracking. In this process, gaseous or light liquid hydrocarbons are heated to 750-950 to induce many free radical reactions.

Then immediately quench the frozen reaction. In this process, put large hydrocarbons.

It is converted to smaller hydrocarbons and reacts to unsaturated hydrocarbons.

Synthesis method from coal:

Coal to synthesize olefins.

MTO): Coal-based olefin technology, which is a new C1 chemical process, refers to methanol synthesized from coal gasified syngas.

It is a chemical technology for the production of low carbon olefins with the help of a fluidized bed reaction form similar to a catalytic cracking unit.

ch = ch + h = ch ch (conditional catalyst, heated).

Normally, ethylene is a colorless and slightly odorous gas with a density of slightly less dense than air, insoluble in water, and easily soluble in organic solvents such as carbon tetrachloride.

Appearance and properties: colorless gas, slightly odorous with hydrocarbons. A small amount of ethylene has a faint sweetness.