Ethylene Vinyl Acetate from Ethylene & VAM (Tubular Process)

The process under analysis comprises three major sections: (1) Polymerization; (2) Separation; and (3) Extrusion and Packaging.

Polymerization. Fresh and recovered ethylene are fed to a primary compressor to be pressurized to 300 bar. The outlet stream is mixed with dried fresh and recycled vinyl acetate monomer (VAM), and an unreacted monomers stream recovered downstream. This mixture is pressurized to 3000 bar in a secondary compressor, and then fed to a tubular reactor at different injection points, so the polymerization takes place. The reactor outlet is expanded to 300 bar and sent to a separation section.

Separation. Firstly, a High-Pressure Separation divides the molten copolymer from unreacted monomers, which are recycled to the 2nd compressor and to a VAM recycle condenser. Waxes formed during the polymerization are condensed and sent to disposal. The bottom stream from the HP Separation is passed through a Low-Pressure Separation, operating at 1.5 bar, to remove remaining unreacted monomers, which are sent to Wax Removal. The copolymer melt is sent to extrusion. A stream from the VAM recycle condenser is fed to a distillation column, were VAM is recovered and recycled to the second compressor, and heavies are disposed as waste.

Extrusion and Packaging. The copolymer melt from the LP Separation is further fed into an extruder, which is used to incorporate the required additives, as well as to pelletize the polymer. The product is then sent to product blending and storage.