Chinese name
terephthalic acid
Foreign name
terephthalic acid
1, 4- dicarboxybenzene
Another name
1, 4- phthalic acid, terephthalic acid, terpenoid terephthalic acid
chemical formula
C8H6O4
molecular weight
166. 13 1
Related video
65438+800,000 plays |03:58
Under the epidemic situation, the pressure of polyester inventory is high, and PTA counterattack is not easy!
Small phase angle
65438+800,000 plays |03:07
Commodity futures closed up in a large area, with Shanghai nickel, PTA and ethylene glycol rising by more than 5% and low-sulfur fuel oil rising by more than 4%.
Financial world
39,000 plays |02:07
The drum head is made of elastic plastic film and polyethylene terephthalate!
Cloth record
5 170 play | 14:34
September 7, 2022 Wave Trend Deduction of Peanut+Corn +PTA+PP-Sean Wave Theory (Video)
Sean wave theory
Basic information, physical and chemical properties, molecular structure data calculation, chemical data, environmental impact, environmental standards, emergency treatment technology, production methods, main uses, storage and transportation conditions, ta said.
Basic information
Chemical formula: C8H6O4
Molecular weight: 166. 13 1.
Si Nuo. : 100-2 1-0
EINECSno。 : 202-830-0
physicochemical property
Density: 1.5 1 g/cm3
Melting point: 427℃ (closed tube)
Flash point: 260℃
Refractive index: 1.648
Appearance: white crystalline powder
Solubility: slightly soluble in water, insoluble in carbon tetrachloride, ether, acetic acid and chloroform, slightly soluble in ethanol, soluble in alkaline solution.
Molecular structure data
Molar refractive index: 40. 1 1.
Molar volume (cm3/mol): 1 14.4.
Isotonic specific volume (90.2 k): 33 1.5.
Surface tension (dyne/cm): 70.3
Polarity (10-24cm3): 15.90.
Computational chemical data
Reference value of hydrophobic parameter calculation (XlogP): None.
Number of hydrogen bond donors: 2
Number of hydrogen bond acceptors: 4
Number of rotatable chemical bonds: 2
Number of tautomers: 0
Polar surface area of topological molecules: 74.6
Number of heavy atoms: 12
Surface charge: 0
Complexity: 169
Atomic number of isotope: 0
Determine the number of atomic solid centers: 0
The number of uncertain atomic solid centers: 0
Determine the number of solid centers of chemical bonds: 0
The number of uncertain chemical bond solid centers: 0
* * * Number of valence bond units: 1
Environmental effect
health hazard
Invasion route: inhalation, ingestion and percutaneous absorption.
Health hazard: It can irritate eyes, skin, mucous membrane and upper respiratory tract, and no occupational poisoning has been reported.
Toxicological data and environmental behavior
Toxicity: low toxicity.
Acute toxicity: LD50 1670mg/kg (abdominal cavity of mice); Rats 3200mg/kg (oral); 3550 mg/kg (taken orally by mice)
Hazard characteristics: In case of high heat, open flame or contact with oxidant, there is a danger of burning.
Combustion (decomposition) products: carbon monoxide and carbon dioxide.
environmental standard
The maximum allowable concentration of harmful substances in the air of workshops in the former Soviet Union: 0. 1mg/m3.
Maximum allowable concentration of harmful substances in water in the former Soviet Union (1975): 0.1mg/l/l.
Occupational exposure limits: OELS (mg/m3) PC-TWA: 8; Personal computer -STEL: 15.
Emergency treatment
Emergency treatment of leakage
Cut off the fire. Wear a gas mask and gloves. Collect it and transport it to an open place for burning. Such as a large number of leaks, collected and recycled or discarded after harmless treatment.
protective measure
Respiratory system protection: Wear a gas mask when the concentration in the air is high.
Eye protection: You can use a safety mask.
Protective clothing: wear work clothes.
Hand protection: Wear chemical resistant gloves when necessary.
Others: Take a shower and change clothes after work. Pay attention to personal hygiene.
Emergency treatment
Skin contact: Take off contaminated clothes and rinse with running water.
Eye contact: immediately open the upper and lower eyelids and rinse with flowing water 15 minutes. See a doctor.
Inhalation: Leave the site and go to a place with fresh air. See a doctor.
Miseating: gargle by mistake, give milk or egg white, and see a doctor.
Fire extinguishing methods: misty water, foam, carbon dioxide, dry powder and sand.
Specialized skills
PTA production process can be divided into two parts: oxidation unit and hydrofining unit. Using acetic acid as solvent, raw material p-xylene is oxidized into crude terephthalic acid by air under the action of catalyst, 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 products.
A method for purifying crude terephthalic acid includes the following steps: drying crude terephthalic acid, ball milling, sieving to make the particle size reach 65438 0-5 microns, soaking in water at 60-65438 000 DEG C, stirring, clarifying, skimming off impurities, and finally centrifuging at 80-65438 000 DEG C.. Crude terephthalic acid (TPA) is the precipitate of alkali decrement wastewater after acid precipitation, and the dry weight content of impurities is 15%- 18%.
The main patent manufacturers of PTA process are BP-Amoco, DuPont -ICI and Mitsui Petrochemical Company. After years of development, the technologies of the above three companies are similar, each with its own characteristics and similar level. The total production capacity of PTA plant using BP-Amoco process in the world is 765,438+760,000 t/a, DuPont -ICI process is 3,495,000 t/a, and Mitsui oil refining process is 6,543.8+250,000 t/a.4-C6H4 (COOH) 2. Colorless crystals. Sublimation occurs above 300℃. Very slightly soluble in water, soluble in dimethyl sulfoxide, dimethylformamide and hexamethylphosphoryl triamine. Because of its low solubility and high melting point, it is difficult to purify.
Terephthalic acid is industrially prepared by oxidizing paraxylene with nitric acid or air under the catalysis of cobalt salt. Terephthalic acid can also be produced by rearrangement of potassium benzoate or potassium phthalate in the presence of cadmium or zinc catalyst and carbon dioxide.
manufacturing method
PTA was discovered in19th century, and it was not until 1949 that British Bremen Chemical Industry Company discovered that PTA (or its derivative dimethyl terephthalate) was the main raw material for polyester production that it began to be produced on a large scale. 198 1 year, the world PTA output has reached 3.485 mt, and the first industrial production method is nitric acid oxidation. With the development of polyester industry, PTA production methods have also developed from various raw materials and through various channels (Figure 1). The most economical and widely used method is high-temperature liquid phase oxidation with p-xylene as raw material (see color chart), with high yield and short process. The low-temperature oxidation reaction of p-xylene has mild conditions and low corrosiveness, but the process is long, which is only used in a few factories. It has also been suggested that p-xylene can be ammoniated and oxidized to produce terephthalonitrile, and then hydrolyzed to produce PTA, but this method has not been produced on a large scale. Due to the high cost of separating p-xylene from mixed xylene, some methods based on other raw materials have been developed. Although some of these methods have long been industrialized, they have not developed, and some are only in the intermediate experimental stage.
Liquid phase oxidation of p-xylene at high temperature
edit
video transmission
Tashuo
1
catalogue
exist