Looking for information on acetic acid

Most of the information on acetic acid is confidential. There should be no complete information online. You can only ask a single question to see if anyone can answer it. The rhodium you asked about is not out of date. It is used by several companies in China, but its additives are changing.

In 1911, Germany built the first industrial unit for acetaldehyde oxidation to synthesize acetic acid. In 1952, the American Celanese Company developed a method for oxidizing low-carbon alkanes to produce acetic acid. The ethylene-acetaldehyde oxidation method developed rapidly in the 1960s. The first Wacker method acetic acid unit was put into production in Europe in 1960. In the same year, the German BASF Company developed a high-pressure and high-temperature methanol oxo synthesis process using methanol as raw material and cobalt as catalyst. In 1968, Mosanto Company of the United States developed a highly active and highly selective catalyst for the carbonylation of methanol to acetic acid using rhodium as a catalyst. In 1970, it established an industrial unit in Texas, United States. Later, in 1983, Eastman Company of the United States successfully developed acetic acid and acetic anhydride co-production technology and built a 225,000 tons/year production unit. At present, foreign acetic acid industrial production technologies mainly include methanol oxo synthesis, acetaldehyde oxidation, and n-butane/light oil oxidation. Among them, acetaldehyde oxidation is divided into ethylene oxidation, acetylene and ethanol oxidation, and the ethylene liquid phase oxidation method is the main one. According to statistics, more than 60% of the world's current acetic acid production is methanol carbonylation, 25% acetaldehyde oxidation, and the rest is butane oxidation. However, with the development of the Mosanto carbonylation process, the proportion of the ethylene acetaldehyde process has gradually decreased. The 272,000 tons/year ethylene acetaldehyde oxidation unit of the American Celanese Company was closed in 1982, and four sets of ethylene acetaldehyde units in Japan were also closed in 1980. There are two main production processes in methanol oxo synthesis: Mosanto/BP and Halcon/Eastman. The Mosanto/BP process is characterized by low raw material consumption, high conversion rate, high product quality, and the ability to regenerate any trace of deactivated catalyst. The process of Halcon/Eastman is basically similar to Mosanto/BP, but the catalyst is different. Halcon/Eastman uses a non-noble metal catalyst, namely nickel acetate/methyl iodide/tetraphenyltungsten series catalyst, while Mosanto/BP uses rhodium as the catalyst. The two process conditions are slightly different.

It seems that more rhodium carbonyl catalysts are used. In addition, Celanese in the United States uses traditional processes to add high concentrations of lithium iodide to rhodium-based catalysts to maintain the stability of the catalyst. This post was last edited by laserting on 2009-4-15 15:15 ]

Which frame of rhodium is the most stable in a catalyst solution? I have read the information, some say that 2+rhodium is stable, and some say that 5+rhodium is stable.

catalyst: Preparation principle of diiododicarbonylrhodium catalyst RhI3 and dilute acetic acid aqueous solution are stirred and mixed in a catalyst dissolving tank, and CO is introduced under heating to react the insoluble RhI3 with CO to generate a rhodium carbonyl complex that is soluble in the reaction solution and has catalytic activity. Thus, a catalyst solution used in the oxo synthesis reaction was obtained.

Cocatalyst (methyl iodide) Preparation principle of methyl iodide The preparation of methyl iodide is divided into two steps: Hydrogen iodide is prepared in the first step, and methyl iodide is prepared in the second step. ①Preparation of hydrogen iodide The reaction mechanism of hydrogen iodide is two steps. Solid iodine is dissolved in hydriodic acid.: CO will be reduced to ； The side reaction is a CO shift reaction catalyzed by HI: When the I2 reaction is completed, the CO shift reaction increases, and the H2 concentration in the reaction exhaust gas increases significantly. The increase in H2 concentration in the exhaust gas is used to judge the reaction end point.

Rhodium metal is still a popular catalyst and is still used by many large acetic acid manufacturers. BP, etc. are all in use, but at the same time they are improving the cocatalyst components in order to achieve better catalytic effects.

When the I2 reaction is completed, the CO shift reaction increases, and the H2 concentration in the reaction exhaust gas increases significantly. The increase in H2 concentration in the exhaust gas is used to judge the reaction end point. I also know that this is the final way to judge the reaction. What is the principle of the reaction? Is it possible that I2+HI=HI3?