As a chemical engineer with extensive experience in the petrochemical industry, I am well-versed in the production processes of various organic compounds, including ethene. Ethene, also known as ethylene, is a simple hydrocarbon with the formula C2H4. It is one of the most important industrial chemicals and is used in the production of a wide range of products, from plastics and solvents to antifreeze and detergents.

The production of ethene typically involves a process known as steam cracking. This is a high-temperature process used to break down larger hydrocarbon molecules into smaller ones, such as ethene. Here's a detailed look at how ethene is made:


1. Feedstock Preparation: The process begins with the preparation of the feedstock, which is typically derived from crude oil fractions. These fractions are rich in hydrocarbons with a high carbon-to-hydrogen ratio. The feedstock is preheated and mixed with steam to reduce its viscosity and improve its flow properties.


2. Steam Cracking: The preheated feedstock and steam mixture is then subjected to extremely high temperatures, typically in the range of 750-950°C. This is achieved in a furnace where the mixture is rapidly heated. The high temperature causes the hydrocarbon molecules to break apart, a process known as pyrolysis. This results in the formation of smaller molecules, including ethene.


3. Quenching: After the pyrolysis reaction, the hot gases are quickly cooled, or quenched, to prevent further reactions. This is typically done by injecting a large amount of cold water or another cooling medium into the reaction chamber.


4. Separation: The cooled gases are then passed through a series of separators and distillation columns to separate the different hydrocarbon products. Ethene is collected and purified in this step.


5. Catalytic Conversion (if required): In some cases, if the primary product is not ethene but another alkene like propene, a subsequent catalytic conversion step may be employed. This involves the use of a catalyst, such as phosphoric acid on a silica support, to convert the alkene into ethene. However, this step is not always necessary, as the primary goal of steam cracking is to produce ethene.


6. Purity and Quality Control: The final product undergoes rigorous purity and quality control checks to ensure it meets the required specifications for industrial use.

It's important to note that the production of ethene through steam cracking is a continuous process. As long as feedstock and steam are continuously supplied to the furnace, ethene will be produced. The process is highly efficient and is the primary method for ethene production globally.

The process described above is a simplified overview of the complex chemical reactions and engineering principles involved in the production of ethene. The actual process can be quite intricate, involving multiple stages of heating, cooling, and separation, all carefully controlled to optimize yield and purity.

Now, let's move on to the next step.

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Ethanol can be made by reacting ethene (from cracking crude oil fractions) with steam. A catalyst of phosphoric acid is used to ensure a fast reaction. Notice that ethanol is the only product. The process is continuous -C as long as ethene and steam are fed into one end of the reaction vessel, ethanol will be produced.read more >>