Technical Applications Wacker-Hoechst-Processes

4 Technical Applications (Wacker-Hoechst Processes) 2.4.1.4.1 Acetaldehyde from Ethylene 

After its discovery this process attracted the highest industrial interest and many plants have been erected in industrial countries all over the world. It replaced processes starting from acetylene or ethanol almost completely. The process is operated in two versions, both in a homogeneous phase [47]. 

For both processes a purification section now follows involving several fractional distillation steps. The yield in both processes is similar, ca. 95 %. Also, 

Monochloroacetaldehyde is a valuable intermediate for the synthesis of organics. Normally such chlorinated products are burnt thermally or decomposed by alkali others are also degraded biologically. Oxalic acid forms insoluble copper oxalate. It is thermally decomposed continuously by heating a small sidestream of the catalyst according to eq. (30). 

Other organics such as chlorinated or resinous products are partly decomposed during normal operation or in this regeneration step, (i) or (m) respectively. Thus, the catalyst solution shows a kind of self-cleaning behavior. As chlorinated products are removed during the purification of acetaldehyde, a corresponding amount 

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