Cradle to Consumer
Identity ID
9e529d19-df66-468d-80ae-403406956c1e
Materials
Associated ID
686190ef-ac2a-4d76-8337-1d4254280214
Included activities starts
Included activities ends
Description
This dataset is a market dataset, representing the consumption market of the region; the dataset includes the transport of the product from the gate to the consumer end, and the transport service is calculated according to the transport situation of this product in this region. Terephthalic acid is primarily used for polyester synthesis, and is also applied in fields such as special polyester production, fine chemicals, coating modification, the preparation of pharmaceutical intermediates and dye auxiliaries. Terephthalic acid is modelled as a pure substance; when modelling this substance the user needs to add a solvent of their choice in the model; the dataset contains the main raw and auxiliary materials, energy, waste and atmospheric emissions of the production process, in which the preliminary treatment of wastewater in the auxiliary units and the waste gas treatment process are included within the dataset boundary, and infrastructure such as the manufacture of production equipment and the construction of plant buildings is not included within the dataset boundary; the data inventory is formed by merging data from multiple sources; the production activities of this product include isomerisation, adsorption separation, oxidation reaction, hydrofining, and waste heat recovery power generation.
Activity Description
The production activities of this product include isomerization, adsorption separation, oxidation reaction, hydrorefining, waste heat recovery and power generation and other processes.
Process Description
Terephthalic acid (PTA for short) has the chemical formula C8H6O4 and CAS number 100-21-0. It is a white crystalline powder under normal temperature and pressure. It is odorless and tasteless, with a melting point of about 425°C (decomposition). It has excellent heat resistance and stable chemical properties at normal temperature. Slightly soluble in water, ethanol, ether, insoluble in benzene, toluene and other aromatic solvents, easily soluble in alkali to form water-soluble salts; it has the typical characteristics of aromatic dicarboxylic acids, can undergo polycondensation reactions with ethylene glycol, and can also undergo esterification, amidation and other reactions. It is an isomer of each other with phthalic acid and isophthalic acid (IPA), and is the core basic raw material in the field of polyester synthesis. Industrially, it is mainly used in the field of polyester synthesis. It is also used in the production of special polyester, the fine chemical industry (raw materials for the preparation of insulating paints, adhesives, and plasticizers), coating modification, and can also be used to prepare pharmaceutical intermediates, dye additives, etc. It is especially suitable for the three core fields of polyester fiber, packaging materials, and engineering plastics. It is a bulk basic raw material in the petrochemical chemical system.
Time period
2016
2026
Geography
China,Ningxia Hui Autonomous Region
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
The classic two-step method (PX liquid phase air oxidation-hydrogenation refining process) is the absolute mainstream technology for terephthalic acid production, accounting for more than 98% of the country's total terephthalic acid production. Using paraxylene (PX) as raw material, it is divided into two steps: liquid phase air oxidation and hydrogenation refining. In the first step, acetic acid is used as the solvent with a cobalt–manganese–bromide composite catalyst. Compressed air is introduced into the p-xylene-acetic acid mixture at 220-225°C and 2.5-3.0 MPa to continuously oxidize it, generating crude terephthalic acid (CTA) with p-carboxybenzaldehyde (4-CBA) as the main impurity. The reaction product is crystallized, filtered, and dried to obtain CTA. The reaction heat can be recovered for use in the steam system and power generation. In the second step, CTA is dissolved in water at 280-290°C and about 7 MPa to form a terephthalic acid aqueous solution, which is then hydrogenated over a palladium/activated carbon catalyst to remove impurities such as 4-CBA. After hydrogenation, the material is crystallized, filtered, washed, and dried to obtain fiber-grade PTA. The purity of the finished product can reach more than 99.9%, meeting the requirements of polyester production.