Acetic acid production process

Acetic acid production process

BP cativa process

BP is the world's largest acetic acid supplier, and 70% of the world's acetic acid production adopts BP technology. BP company launched cativa technology patent in 1996. Cativa process adopts a new catalyst system based on iridium and uses a variety of new auxiliaries, such as rhenium, ruthenium, osmium, etc. iridium catalyst system is more active than rhodium catalyst, with less by-products and can be operated under low water concentration (less than 5%). It can greatly improve the traditional methanol carbonylation process, reduce production costs by up to 30%, and reduce expansion costs by 50%. In addition, as the water concentration decreases, the co utilization efficiency increases and the steam consumption decreases.  [8]

Celanese aoplus process

Celanese is also one of the largest acetic acid producers in the world. In 1978, Hearst Celanese company (now Celanese company) put the Monsanto process acetic acid plant into industrial operation in Lake Claire, Texas, USA. In 1980, Celanese company launched the aoplus method (acid optimization method) technology patent, which greatly improved the Monsanto process.

Aoplus process improves the stability of rhodium catalyst by adding high concentration inorganic iodine (mainly lithium iodide). After adding lithium iodide and iodomethane, the water concentration in the reactor is reduced to 4% ~ 5%, but the carbonylation reaction rate remains at a high level, thus greatly reducing the separation cost of the unit. The change of catalyst composition makes the reactor run at low water concentration (4% ~ 5%), which improves the carbonylation reaction yield and separation and purification capacity.  

Toxicological data of acetic acid

1. Acute toxicity

LD50: 3530mg / kg (rat oral); 1060mg / kg (rabbit percutaneous)

LC50: 13791mg / m3 (inhalation in mice, 1H)

2. Irritant

Rabbit percutaneous: 50mg (24h), mild irritation.

Rabbit eyes: 5mg (30s), mild irritation (rinse with water).

3. Mutagenicity

Microbial mutagenesis: E. coli 300ppm (3H).

Sister chromatid exchange: human lymphocytes 5mmol / L.

Cytogenetic analysis: hamster ovary 10mmol / L.

4. Other

The lowest oral toxic dose (tdlo) of rats: 700mg / kg (18D, postpartum), which has an impact on the behavior of newborn rats.

The lowest toxic dose (tdlo) in testis of rats: 400mg / kg (1D, male), which has an effect on male fertility index.

Ecological data of acetic acid

1. Ecotoxicity

LC50: 92 ~ 106mg / L (48h), 79 ~ 88mg / L (96h) (black headed fish); 75mg / L (96h) (blue gill sunfish); 251mg / L (96h) (mosquito eating fish)

EC50: 32mg / L (48h) (water flea)

IC50: 90mg / L (72h) (algae)

2. Biodegradability

MITI-I test showed that the initial concentration was 100ppm, the sludge concentration was 30ppm, and the degradation rate was 74% after 2 weeks.

3. Non biodegradability

In the air, when the hydroxyl radical concentration is 5.00 × The half-life of degradation is 22d (Theory) at 105 cells /