How does hydration of ethene work?
How does hydration of ethene work?
This page describes the mechanism for the hydration of ethene to make ethanol using phosphoric(V) acid as the catalyst. Ethene is mixed with steam and passed over a catalyst consisting of solid silicon dioxide coated with phosphoric(V) acid. The temperature used is 300°C and the pressure is about 60 to 70 atmospheres.
What is the product of hydration of ethene?
Ethanol
In a hydration reaction, the water molecule reacts with an alkene to generate an alcohol. Ethanol can be prepared by the reaction of alkene with the water molecule. Ethene molecules react with sulphuric acid generating an alcohol, that is ethanol.
What type of process is hydration of ethene?
It then compares that method with making ethanol by fermentation. Ethanol is manufactured by reacting ethene with steam. The catalyst used is solid silicon dioxide coated with phosphoric(V) acid. The reaction is reversible….
| Fermentation | Hydration of ethene | |
|---|---|---|
| Rate of reaction | Very slow. | Very rapid. |
What conditions are needed for hydration of ethene?
Hydration of ethene v fermentation
| Fermentation | Hydration of ethene | |
|---|---|---|
| Rate of reaction | Slow | Fast |
| Conditions needed | Warm (30°C), normal pressure (1 atm) | High temperature (300°C) and high pressure (60-70 atm) |
| Purity of product | Impure (needs treatment) | Pure (no by-products made) |
| Energy needed | A little | A lot |
Why is the hydration of ethene an important industrial reaction?
The hydration of ethene has an atom economy of 100%, showing that all the atoms in the reactants form the desired product. As it also has a higher rate of reaction, the hydration of ethene appears to be the better way to make ethanol.
Is the hydration of ethene exothermic?
Ethanol is manufactured by reacting ethene with steam. The reaction is reversible, and the formation of the ethanol is exothermic.
Is hydration of ethene electrophilic addition?
Reaction. The alkene hydration reaction is an example of an electrophilic addition reaction, in which the π electrons in the alkene double bond act as a nucleophile (or, if you like, an electrophile is added to the double bond).
Why is hydration of ethene non renewable?
Ethanol that is used in industry can also be made from ethene. Ethanol made in this way is a non-renewable fuel because the ethene it is made from comes from fossil fuels. These fossil fuels cannot be replaced and are a finite resource. > The water is heated to make steam.
Why is hydration of ethene better than fermentation?
Fermentation has a lower percentage yield and rate of reaction than the hydration of ethene. As it also has a higher rate of reaction, the hydration of ethene appears to be the better way to make ethanol.
How is ethanol made by the steam hydration of ethene?
Ethanol can also be made by reacting ethene with steam. Mixture of ethene and steam is passed over a phosphoric acid catalyst at a temperature of 300°C and 60-70 atmospheres of pressure. The ethanol is condensed as a liquid. The ethene required for this reaction is obtained from crude oil.
Is hydration an electrophilic addition reaction?
The alkene hydration reaction is an example of an electrophilic addition reaction, in which the π electrons in the alkene double bond act as a nucleophile (or, if you like, an electrophile is added to the double bond).
What are the advantages of hydration of ethene?
Hydration of Ethene
| Hydration of Ethene | |
| Advantages Continuous so it keeps on being produced Phosphoric acid which is a catalyst 100% atom economy | Disadvantages Non renewable process High temperature and pressure wastes energy – expensive |
| Evaluation |
How do you hydrate ethene to make ethanol?
This page describes the mechanism for the hydration of ethene to make ethanol using phosphoric (V) acid as the catalyst. Ethene is mixed with steam and passed over a catalyst consisting of solid silicon dioxide coated with phosphoric (V) acid. The temperature used is 300°C and the pressure is about 60 to 70 atmospheres.
What is the chemical reaction of ethene to make ethanol?
Ethanol can be manufactured by the hydration of ethene. In this reaction, ethene (which comes from cracking crude oil fractions) is heated with steam in the presence of a catalyst of phosphoric acid (to speed up the reaction): This reaction typically uses a temperature of around 300°C and a pressure of around 60–70 atmospheres.
How can the reaction of ethene with steam be reversed?
The reaction of ethene with steam to form ethanol can be reversed. This allows ethanol to be converted into ethene. A catalyst of hot aluminium oxide is used to speed up the reaction. This is called a dehydration reaction.
