Vinyl acetate manufacture

Of course, the benefits of microfabricated and stractured reactors are also applicable to even larger scale processes. For example, Evonik s development of a production-scale microstructured reactor for vinyl acetate manufacture (150000t per annum) claims depreciation and operating cost savings of 3 million per year [25]. 

Three main routes for vinyl acetate manufacturing are employed today, as follows... 

Figure 10.2 Design of the reactor for vinyl-acetate manufacturing in a recycle system.

In contrast to acetaldehyde, where a choice exists between several well-established manufacturing processes, vinyl acetate has been produced until recently by two principal methods—i.e., by the catalytic vapor-phase acylation of acetylene and by the acetalization of acetaldehyde. The new procedure for vinyl acetate manufacture consists of oxidizing ethylene in acetic acid—a process closely related to the Wacker acetaldehyde process. All three manufacturing approaches are outlined in Table XII. 

Ally Acetate can be a starting material for polymers as a comonomer, for glycidyl acetate as a component of epoxy resins, for glycerol, for allyl alcohol by hydrolysis, and for the synthesis of allyl esters of higher acids or other compounds by transesterification or transallylation. Processes for the commercial production of allyl acetate have been developed by Bayer and Hoechst [60], and some Japanese companies. Such processes work in the gas-phase under similar conditions to those used in vinyl acetate manufacture and are currently operated by Showa Denko and Daicel [61]. 

For the latest commercial developments in fluid bed production of vinyl acetate manufacture, see Sect. 6.5.1. 

Fig. 11.2. Vinyl acetate manufacture from ethylene. Bayer/Hoechst and USt Chemicals vapor phase processes. 

The maintenance of a supported liquid layer in gas-phase reactions is also important in other heterogeneous catalytic applications, such as the Bayer/Hoechst process for vinyl acetate manufacture. However, in these systems, the catalytic metal is reduced to the metallic state, leading to significant mechanistic differences from the formally related homogeneous Wacker-type alkene oxidation/acetoxylation processes (section 11.7.7.3). 

Mowilith n. Poly(vinyl acetate), manufactured by Hoechst, Germany. 

Saflex n. Poly(vinyl acetal), manufactured by Monsanto, USA. 

Until the mid-1960s, vinyl acetate manufacture was based almost entirely on acetylene. Since that time, however, more economical ethylene-based processes have been developed and now very few manufacturers use the acetylene route. 

Ethylene Recovery in Ethylene Oxide and Vinyl Acetate Manufacturing Plants... 

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