[Chemical Knowledge]：Properties, uses, upstream and downstream raw materials, storage methods of purified terephthalic acid, cas number

Purified Terephthalic Acid Properties

Purified terephthalic acid (Purified Terephthalic Acid, PTA) is an important chemical raw material, its chemical formula is C8H6O4. PTA is a white crystalline powder with high purity and stability, with a melting point of 300°C and a density of about 1.52g/cm³. PTA is poorly soluble in water, but soluble in alkaline solutions and some organic solvents. These physical and chemical properties make it an important raw material for polyester production, but also put forward specific requirements for its storage and transportation.

Purified terephthalic acid use

The main use of PTA is in the production of polyester materials, especially polyethylene terephthalate (PET). PET is widely used in fiber, bottled beverage containers, film and so on. PTA is also used in the manufacture of coatings, engineering plastics and adhesives. Due to its good mechanical properties and chemical stability, polyester materials made of PTA are widely used in textile, packaging, electronics, automotive and other industries.

Upstream raw materials

PTA production relies primarily on paraxylene (p-Xylene, PX) as an upstream feedstock. PX generates terephthalic acid (Terephthalic Acid, TA) through oxidation reaction, and further removes impurities through purification process to produce high purity PTA. Paraxylene is one of the by-products in the petroleum refining process, so the development of petrochemical industry directly affects the production cost and supply stability of PTA.

Downstream Products

The downstream products of purified terephthalic acid mainly include polyester fiber and PET resin. Polyester fibers are widely used in the textile industry to produce clothing, bedding and industrial textiles. PET resin is used in the manufacture of various packaging materials, especially beverage bottles and food containers. In recent years, with the improvement of environmental awareness, the recyclability and recycling of PET materials have also become the focus of attention, further promoting the growth of PTA demand.

Production process

The production process of PTA mainly includes two steps: oxidation and purification. Para-xylene reacts with air in the oxidation reactor to produce crude terephthalic acid. Then, the crude terephthalic acid is subjected to hydrogenation treatment and rectification to remove impurities and by-products to obtain high-purity purified terephthalic acid. In this process, the choice of reaction conditions and catalyst is very important for the quality and yield of the product.

Environmental Protection and Safety

In the production process of PTA, the oxidation reaction will produce a certain amount of by-products and waste gas, such as formic acid, acetic acid and carbon dioxide. Therefore, environmental protection has become an important aspect of PTA production enterprises need to pay attention. Enterprises usually adopt advanced waste gas treatment technology and recycling measures to reduce environmental pollution. Because PTA powder has certain flammability and explosiveness, it is necessary to strictly control the temperature, humidity and dust concentration during production and storage to ensure safe production.

market demand

The global PTA market demand is mainly driven by the demand for polyester fiber and PET products. In recent years, with the development of economy and the improvement of residents' living standards, especially in the Asian market, the demand for textiles and packaging materials has continued to grow, which has led to the rapid development of the PTA market. The strengthening of environmental regulations and the promotion of renewable PET materials have also brought new opportunities and challenges to the PTA market.

Storage method

Purified terephthalic acid needs to be protected from moisture and high temperatures during storage. Generally, PTA should be stored in a dry, ventilated, cool warehouse, away from direct sunlight and fire. Storage containers shall be plastic or paper bags with good sealing and placed on pallets to prevent moisture and contamination. The storage area shall be equipped with necessary fire fighting equipment to deal with sudden accidents.

Market Prospects

In the future, with the rise of emerging economies and the acceleration of industrialization, the prospects for the PTA market remain promising. Especially in China and India in Asia, the demand for polyester fiber and PET products will continue to grow, driving the development of the PTA industry. The trend of environmental protection and sustainable development will prompt enterprises to increase investment in green production technology and circular economy mode, so as to enhance the market competitiveness of PTA.

Conclusion

As an important chemical raw material, purified terephthalic acid has a wide range of applications and good market prospects. By optimizing the production process, strengthening environmental protection measures and improving the level of storage management, the quality and supply stability of PTA can be further improved to meet the needs of downstream industries. With the continuous growth of market demand and technological progress, the PTA industry will continue to develop in the future and provide solid raw material protection for related industries.