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Production processes styrene stripping

Polymers. Foam is often a particular problem in the production of polymers. There are numerous situations where foam can reduce the production capacities of vats and vessels and cause problems in pumps, meters, and other equipment, particularly distillation and evaporation equipment. Foam is frequently a problem when stripping off a monomer from a polymer. Examples are in the production of styrene-butadiene [9003-55-8] and acrylonitrile-butadiene [9003-18-3] rubber latices. These latices are stabilized by surfactants that greatly contribute to foaming difficulties. Another problem foam area is in the stripping of imreacted monomer from poly(vinyl chloride) suspensions. In this process, vinyl chloride [75-01-4], a gas at room temperature, is liquefied by pressure, emulsified in water with surfactants and catalysts, and heated to bring about polymerization. The recovery of unpolymerized monomer by distillation from this mixture produces a severe foaming problem. [Pg.601]

One of the key benefits of anionic PS is that it contains much lower levels of residual styrene monomer than free-radical PS (167). This is because free-radical polymerization processes only operate at 60—80% styrene conversion, whereas anionic processes operate at >99% styrene conversion. Removal of unreacted styrene monomer from free-radical PS is accompHshed using continuous devolatilization at high temperature (220—260°C) and vacuum. This process leaves about 200—800 ppm of styrene monomer in the product. Taking the styrene to a lower level requires special devolatilization procedures such as steam stripping (168). [Pg.517]

In the St. Clair River Area of Concern, Dow Chemical Canada, Inc. of Sarnia, Ontario has expanded the process water collection system at its EB/Styrene plant to maximize the recovery of organic compounds. The EB/Styrene plant uses ethyl benzene, styrene, benzene, and toluene in the production of more complex organic compounds. During the manufacturing process, these four compounds end up in the wastewater. The wastewater collection system has been expanded recently to recover all process wastewater and divert it to the purification tower where these four contaminants are steam stripped out and then reused as part of the fuel stream to produce steam and electricity (P. Murphy, pers. comm., Dow Chem. Can. Inc., Sarnia, Ontario, 1989). This project was implemented in 1986 at a cost of 270,000. The tower removes approximately 250 kg/d of contaminants (Mackinnon 1989) which are then added to other fuel streams providing a savings in displaced fuel cost of approximately 20,000 per year (P. Murphy, pers. comm., Dow Chem. Can. Inc., Sarnia, Ontario, 1989). [Pg.133]


See other pages where Production processes styrene stripping is mentioned: [Pg.279]    [Pg.469]    [Pg.65]    [Pg.99]    [Pg.700]    [Pg.128]    [Pg.621]    [Pg.2863]    [Pg.369]    [Pg.283]    [Pg.559]    [Pg.609]   
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