Cradle to Gate
Identity ID
fc090a07-cbe3-4b65-bfd9-784b3ae285d6
Materials
Associated ID
ed487fa9-31ca-4df4-a378-cf22aa8620d2
Included activities starts
Included activities ends
Description
Phthalic anhydride is an important organic chemical raw material, widely used in the synthesis of phthalate plasticizers and in resin production, and can also be used to prepare dyes and pharmaceutical intermediates, pesticides and plastic additives, food additives, fragrances, etc. Phthalic anhydride is modeled as a pure substance; when modeling this substance, users need to add a solvent of their choice to the model. This dataset includes the main raw and auxiliary materials, energy, waste and atmospheric emissions of the production process, in which the wastewater preliminary treatment in the utility processes and the waste gas treatment process are included within the dataset boundary, the by-product high pressure steam is partly reused in production, while infrastructure such as the manufacture of production equipment and plant construction is not included within the dataset boundary; the inventory is formed by merging data from multiple sources; the production activities of this product include naphthalene refining, oxidation reaction, condensation recovery, phthalic anhydride refining, steam recovery and other process steps. High pressure steam is a by-product of this production process.
Activity Description
The production activities of this product include naphthalene refining, oxidation reaction, condensation recovery, phthalic anhydride refining, steam recovery and other processes.
Process Description
Phthalic anhydride (referred to as phthalic anhydride) has the chemical formula C8H4O3 and CAS number 85-44-9. It is a white needle-like or flake crystal at room temperature and pressure. It has a slightly pungent odor. The melting point is about 131°C and the boiling point is about 284°C. It sublimes easily and can be slowly hydrolyzed into phthalic acid when exposed to water. Slightly soluble in cold water, easily soluble in hot water, ethanol, ether, benzene and other organic solvents. It has active chemical properties and can undergo esterification, acylation, addition and other reactions. It is an important organic synthesis intermediate for aromatic dibasic acid anhydrides. Industrially, it is mainly used in plasticizer synthesis (as a core raw material to prepare various phthalate plasticizers, suitable for the processing of PVC and other polymer materials) and resin production; it is also used in the fine chemical industry (preparation of dye intermediates, pharmaceutical intermediates, pesticides, plastic additives, etc.), chemical fiber and papermaking (as a raw material for fiber treatment agents and paper sizing agents), and can also be used to prepare food additives, spices, etc.
Time period
2016
2026
Geography
China
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
The naphthalene catalytic oxidation method is the traditional mainstream technology for the production of phthalic anhydride. It is produced by air oxidation of naphthalene under the action of a catalyst. The process is mature and the raw materials come from a wide range of sources. It accounts for about 40% of the total phthalic anhydride production in the country. Together with the o-xylene oxidation method, it constitutes two mainstream technical routes. This data set represents the mainstream technology: using naphthalene catalytic oxidation method, the production mainly includes naphthalene refining, oxidation reaction, condensation recovery, phthalic anhydride refining, steam recovery and other processes:
1. Naphthalene refining: In order to meet the requirements for deep processing and utilization of naphthalene, the static step-by-step melting and crystallization method is used to refine and purify industrial naphthalene.
2. Oxidation reaction: After the air passes through the filter, air blower and air preheater, it is pressurized and heated and then enters the gasifier through Manturi. The mixed gas of naphthalene and air enters from the top of the reactor. This reaction is a strong exothermic reaction; on the surface of the V-Ti series chemical agent, naphthalene is oxidized by air to generate phthalic anhydride. The phthalic anhydride gas is discharged from the bottom of the reactor and is cooled to 170°C by the gas cooler before entering the switching condenser.
3. Condensation recovery: The phthalic anhydride contained in the reaction gas is recovered by condensation in the switching condenser.
4. Phthalic anhydride refining: The reaction by-products in the crude phthalic anhydride are decomposed or polycondensed at high temperatures. The phthalic acid in the crude phthalic anhydride is decomposed into phthalic anhydride and water, and naphthoquinone and other heavy components are converted into resin to facilitate distillation and separation. The final product is then obtained through distillation.
5. Steam recovery: The phthalic anhydride plant produces high-pressure steam by-product, part of which is recycled for production, and the remaining part is used as a by-product.