PTA is the abbreviation of purified terephthalic acid, and it is one of the important bulk organic raw materials. Its main use is to produce polyester fiber (polyester), polyester bottle chips and polyester films, which are widely used in chemical fiber, light industry, electronics, construction and other aspects of the national economy and are closely related to people's living standards. PTA futures, that is, the dominant trading variety with phthalic acid as the subject matter, is a futures variety listed on Zhengzhou Commodity Futures Exchange. The application of PTA is relatively concentrated. More than 90% of PTA in the world is used to produce polyethylene terephthalate (PET), and other parts are used as raw materials for polypropylene terephthalate (PTT), polybutylene terephthalate (PBT) and other products. PTA production process can be divided into two parts: oxidation unit and hydrofining unit. The raw material PX is oxidized into crude terephthalic acid with air in the presence of catalyst and acetic acid as solvent, and then the crude product is obtained by crystallization, filtration and drying in turn. Crude terephthalic acid is hydrogenated to remove impurities, then crystallized, centrifugally separated and dried to obtain PTA finished products.
Due to the rapid development of polyester industry in China, domestic PTA production is far from meeting the demand. The difference is made up by imports. In 2005, the domestic output was 5.89 million tons, and the consumption was 1.2 1.4 million tons, of which the import volume was 6.49 million tons. The dependence on imports is 56%.
In order to meet the domestic market demand for PTA consumption, many projects have been built and expanded in PTA production capacity in recent two years. With the completion and commissioning of these projects, the domestic PTA production capacity will be greatly improved, but there will still be a certain gap compared with the growth of consumer demand. Compared with the polyester production line that can be put into production in one year, PTA project needs at least one and a half to two years. It is estimated that by the end of 2007, the PTA production capacity in China will reach about120,000 tons/year. But what is certain is that with the growth of domestic PTA supply capacity, the dependence on imports will gradually decrease.
PTA is continuous production and consumption. Production and consumption can be adjusted according to market conditions. At the same time, PTA spot trading is mainly based on direct sales, and the relationship between upstream and downstream production and sales is relatively stable, with a high production and sales rate. Therefore, manufacturers have little inventory. PTA has high value and takes up a lot of funds. Downstream polyester manufacturers generally only maintain the consumption of 10 days or more. General traders and spot speculators have relatively large inventories.