[Haichuan Chemical News] Environmental impact assessment begins for Fujian Baihong Petrochemical Co., Ltd.’s project to produce 2.5 million tons of purified terephthalic acid per year

Background of the project: Fujian Province currently has a PTA production capacity of only 6.6 million tons. Of this amount, 2.1 million tons have been shut down or see reduced production due to environmental regulations or owner-related reasons; as a result, only 4.5 million tons of PTA production capacity remains. There is therefore a severe overcapacity for p-xylene in Fujian Province. The polyester fiber industry in Fujian has seen rapid development in recent years, with its production capacity ranking third in the country. However, most of the raw material PTA is purchased from Jiangsu and Zhejiang, which leads to higher raw material costs and a reduced profit margin. In order to address the imbalance in the regional development of aromatic compounds and related industries, to achieve the goal of integrating the entire industrial chain as outlined in Fujian Province’s 13th Five-Year Plan, and to meet the urgent need to adapt this integrated industrial chain to market demands, Fujian Baihong Petrochemical Co., Ltd. plans to build a facility in the Petrochemical Park in Quanzhou Port City capable of producing 2.5 million tons of purified terephthalic acid per year. Project Overview: The 2.5 million tons per year refined terephthalic acid production project of Fujian Baihong Petrochemical Co., Ltd. is located in the Nanshan area of the Quangang Petrochemical Industrial Zone in Fujian Province. It covers an area of 465.33 mu and is a new construction project. The project utilizes INVISTA’s patented PTA production technology; using p-xylene as the main raw material, acetic acid as a solvent, cobalt and manganese as catalysts, and bromine as a promoter, it produces high-purity terephthalic acid through PX oxidation and product purification. The main construction of the project involves building a PTA production facility with an annual output of 2.5 million tons, which mainly includes an oxidation unit and a refining unit ； Complemented by a methanol-to-hydrogen plant and high-temperature high-pressure steam gas boilers ； Environmental protection projects such as the construction of auxiliary production facilities, PTA finished product warehouses, storage areas for liquid raw materials and auxiliaries, circulating cooling water stations, demineralized water stations, comprehensive wastewater treatment plants, reclaimed water reuse systems, and waste gas treatment systems. 　　 The total investment for the project is 5,722.63 million yuan, of which approximately 179.5 million yuan is allocated to environmental protection measures, accounting for 3.14% of the total investment.

Project technology, scale of construction, and product plan: (1) Technology to be used: The project will employ INVISTA’s patented PTA production technology, which uses p-xylene as the main raw material, acetic acid as a solvent, cobalt and manganese as catalysts, and bromine as a promoter. Through the oxidation of p-xylene and subsequent purification of the product, terephthalic acid (PTA) is produced. (2) Construction scale ① PTA plant production capacity: 2.5 million tons of purified terephthalic acid (PTA) per year. ②The production scale of the accompanying hydrogen generation facility: The hydrogen required in the PTA refining process is produced and supplied by the project owner itself. The project includes two sets of methanol cracking hydrogen production units, with each set having a capacity of 700 Nm3/h; the PSA units are shared among them. During driving operations, both hydrogen production systems operate simultaneously; once the PTA plant is running stably, the process exhaust gas from the purification reactor is sent back to the hydrogen production unit for further processing. At this point, only one methanol cracking hydrogen production system is needed, with an operating load of over 80%. (3) Product plan: The main product of this project is purified terephthalic acid.

Project composition: The main part of this project involves the construction of a PTA production facility with an annual output of 2.5 million tons, which primarily includes an oxidation unit and a refining unit； Used in conjunction with hydrogen production equipment ； Construct environmental protection facilities such as auxiliary production units, PTA finished product warehouses, storage areas for liquid raw materials and additives, circulating cooling water stations, demineralized water stations, comprehensive wastewater treatment plants, and reclaimed water reuse systems.

Process route selection: This project utilizes INVISA’s latest PTA technology. Using p-xylene as the raw material, and under the action of catalysts, p-xylene is first oxidized with air to produce crude terephthalic acid, CTA; thereafter, CTA is refined through processes such as hydrogenation and crystallization separation to yield pure terephthalic acid, PTA. The hydrogen used in the refining process is obtained from a methanol-to-hydrogen plant provided by the project constructor. A methanol-to-hydrogen plant uses methanol as raw material to produce hydrogen through cracking and pressure swing adsorption purification.

Shaoxing Yuandong Petrochemical currently possesses PTA production facilities equipped with three patented processes: Eastman’s low-temperature oxidation process, Kunlun Engineering’s medium-temperature oxidation process, and Invista’s high- and medium-temperature oxidation process. It is the only company in the PTA industry to have facilities using all three of these processes. During the PTA production process, to ensure product quality, it is necessary to remove reaction by-products, namely the waste residues, in a timely and effective manner. The residues from the Eastman process are divided into residual powder filtered through a wick filter, and residual lumps obtained through mother liquor extraction. The residues from the Kunlun process and the Invista process are divided into the oxidation residue obtained from the oxidation mother liquor via a thin-film evaporator, and the solid material separated and precipitated from the refined wastewater. The compositions of the 6 types of residues vary significantly depending on the process used.

Another private enterprise that has crossed over from the textile industry into the petrochemical sector. Where does the raw material PX come from? Is it from Tenglong Aromatics, which resumed operations recently?