Petrochemical refers to an industry in which hydrocarbons in crude oil or natural gas are converted into various chemical products used in other industries after undergoing a series of chemical processes. This industry is one of the sub-branches of the chemical industry, which was created from the combination of the two words petroleum and chemical.
The scope of application of the products of this industry has expanded from the production of fuel for guided missiles and satellites to the raw material of some medicines.

Companies active in the petrochemical industry can be divided based on the type of raw material or final product or based on its application. This division, according to whether they use received hydrocarbon carriers as fuel or feed, is as follows:

Division based on hydrocarbon carriers as fuel:
1) Liquid fuel
2) gas fuel

Division based on hydrocarbon carriers as feed:
1) petroleum products
2) Gas and ethane
3) liquids and gas condensates

Therefore, according to this division, it can be said that the feed of petrochemical companies are placed in two categories, liquid and non-liquid (gas). Most of the companies in this industry use non-liquid (gas) feed. In the figure below, several petrochemical feed types are specified.

Petrochemical end products
Methanol

Methanol or methyl alcohol is produced in two ways: high pressure and modern method, in which catalysts are used that operate at low pressures and are more effective. Methanol is used in the preparation of formaldehydes (formalins) for household use and the production of resins, acetic acid, hydrogen fuels and dimethyl ether (DME) as a clean fuel and substitute for diesel fuel and hydrogen fuels.

Simply, the process of producing methanol from natural gas is as follows:

Synthesis gas production
Steam reforming is the simplest and most widely used synthesis gas production method

Catalytic synthesis of methanol from synthesis gas
At this stage, carbon dioxide and hydrogen react with each other and lead to the production of methanol.

Distillation
By separating water from crude methanol, pure methanol is obtained.