Acetic acid from methanol and

Formation of acetic acid from methanol and carbonylation of alcohols still are important industrial problems, but milder conditions are needed. Other metals, such as rhodium, have proved to be more suitable. 

In homogeneous catalytic systems we witnessed a new process for the production of acetic acid from methanol and carbon monoxide using a transition metal complex, thus displacing the earlier process employing ethylene as the starting material. The use of immobilized enzymes makes possible the commercial conversion of glucose into fructose. 

Catalysts used to convert ethylene to vinyl acetate are closely related to those used to produce acetaldehyde from ethylene. Acetaldehyde was first produced industrially by the hydration of acetylene, but novel catalytic systems developed cooperatively by Farbwerke Hoechst and Wacker-Chemie have been used successfully to oxidize ethylene to acetaldehyde, and this process is now well established (7). However, since the largest use for acetaldehyde is as an intermediate in the production of acetic acid, the recent announcement of new processes for producing acetic acid from methanol and carbon monoxide leads one to speculate as to whether ethylene will continue to be the preferred raw material for acetaldehyde (and acetic acid). 

The novel synthesis required fewer process steps, and this resulted in lower costs and investment. In 1969, another advance was announced—the synthesis of acetic acid from methanol and carbon monoxide with essentially no by-products or co-products.15 16... 

The main large-scale metal catalyzed reactions involving addition of CO (rather than CO + H2) to an organic substrate are the manufacture of acetic acid from methanol and the related production of acetic anhydride from methyl acetate. The syntheses of some other carboxylic acids and the conversion of a substituted benzyl alcohol to ibuprofen involve similar reactions. 

The synthesis of acetic acid from methanol and CO is a process that has been used with great commercial success by Monsanto since 1971. The mechanism of this process is complex a proposed outline is shown in Figure 14-16. As in the hydroformylation process, the individual steps of this mechanism are the characteristic types of... 

Encouraged by the interesting results obtained in the high-pressure synthesis of acetic acid from methanol and carbon monoxide using nickel, cobalt, and iron halides as catalysts (5-7), the synthesis of glycolic acid from formaldehyde, carbon monoxide and water has been studied using various nickel, cobalt, and iron catalysts. 

Since coal contains more carbon than required for methanol production, the selection of a suitable gasification process might ensure that methanol could be produced in an ideal combination with high-CX) gases - a route which would be attractive above all for the production of acetic acid from methanol and CO, as shown by the above-mentioned plant in the USA. 

The Monsanto acetic acid process produces acetic acid from methanol and CO gas under fairly mild conditions (I80 C, 30-40 atm). The process utilizes a square planar Rh(l) catalyst. As shown in Figure 19.33, the first step in the catalytic mechanism is the OA of methyl iodide to form an 18-electron compound. In the second step, CO insertion (alkyl migration) occurs, resulting in a 16-electron species. Carbon monoxide adds to the vacant coordination site to r enerate a saturated compound, which then undergoes RE of CH3COI to regenerate the catalyst. The CH3COI product is further processed by reaction with water to make acetic acid and HI. The latter... 

Each year the United States produces over 2.5 million tons of acetic acid from methanol and carbon monoxide. The primary use of acetic acid is in the synthesis of vinyl acetate, which is used in paints and adhesives. 

A major decrease in the capacity to synthesize industrial acetic acid from methanol and CO or by other chemical processes may occur at the end of the next century due to depletion of natural gas and petroleum resources together with an increasing demand for these materials worldwide. With price increases accompanying this situation, bacteria-based processes can certainly become major players in the glacial acetic acid market. 

Glacido A process for making acetic acid from methanol and carbon monoxide. 

Presently the number of industrial processes using metal complex catalysts is continuously increasing. They include such classical large-tonnage processes as polymerization on the Ziegler catalysts, olefin oxidation by molecular oxygen to aldehydes, hydroformylation of saturated compounds, preparation of acetic acid from methanol and carbon monoxide, synthesis of adiponitrile fijom butadiene, and others. 

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