What is coal tar mainly used for? Who can tell me its technological process is in urgent need?

Coal tar coatings are widely used in ships and heavy-duty anti-corrosion coatings, and are also used to make epoxy coal tar coatings. Excellent anticorrosion performance and low price, but it pollutes the environment and has been gradually eliminated.

Coal tar is an important chemical recovery product in coking process, and it is a complex mixture composed of thousands of components. At present, more than 500 single compounds have been isolated and identified, accounting for about 55% of the total coal tar, including benzene, xylene, naphthalene and other 174 neutral components. Acidic components such as phenol and cresol and 1 13 alkaline components. Many compounds in coal tar are precious raw materials for plastics, synthetic fibers, synthetic rubber, pesticides, medicines, high-temperature resistant materials and national defense industry, and some polycyclic aromatic hydrocarbons cannot be produced and replaced by petrochemical industry. Coal tar is mainly used for processing and producing light oil, phenol oil, naphthalene oil and modified asphalt. After deep processing, various chemical raw materials such as benzene, phenol, naphthalene and anthracene are obtained. There are many products and a wide range of uses.

Through further processing, various products can be separated from various fractions of tar. The main products currently extracted are:

(1) Naphthalene is used to produce phthalic anhydride, which is used to produce resins, engineering plastics and dyes. Paint and medicine.

(2) Phenol and its homologues produce synthetic fibers, engineering plastics, pesticides, medicines, fuel intermediates, explosives, etc.

(3) Anthraquinone fuel made from anthracene, synthetic kneader and paint.

(4) Phenanthrene is an isomer of anthracene, which is second only to naphthalene in content and has many uses. Because of its large output, it needs further development and utilization.

(5) Carbazole is an important raw material for dyes, plastics and pesticides.

(6) Asphalt is the residue after tar distillation, and it is a mixture of many polycyclic polymer compounds. Used for making roof coatings, moisture-proof layers, road construction, production of pitch coke and electric furnace electrodes.

At present, advanced tar refiners have extracted more than 230 kinds of products from tar, and centralized processing is developing towards scale.