Environmental, Cross-Media Effects

Spent catalyst production High About lOOx lower About lOOOx lower (Pt of spent catalyst can be reclaimed after many years of operation) 

Product treatment Acid removal needed Add removal needed None 

With caustic Creates waste Creates waste water None 

Acid-soluble oil Up to about Less then sulfuric. None 

Safety Unit-specific safety Very specific safety No special precautions 

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In principle, accidental releases of hazardous chemicals may affect all environmental media (air, water and soil) and consequently the food-chain, independent of the type of release and the environmental medium initially affected. Explosions or leaks of inflammable materials can release quantities of toxic chemicals into the atmosphere, the distribution of which depends on the height of the plume and the meteorological conditions. The chemicals released may subsequently contaminate land, water, food crops or livestock. While most chemical accidents occurring in fixed installations tend to be contained within the industrial compound itself, the effects generated by major chemical accidents may cross national borders. 

Polymerization Processes. A variety of processes are used commercially to homopolymerize and copolymerize acrylic acid and methacrylic acid. On the basis of economics and environmental considerations, water is generally the preferred industrial solvent or polymerization medium. However, the choice of process is usually dictated by the requirements of the polymer to be produced. As already indicated, pH influences the rate of polymerization. Comonomers and molecular weight of the polymer to be produced also have a profound effect on the tsqje of polymerization process that can be used and on the type of product obtained. The contents of Table 2 indicate the change from water-soluble to alkab-soluble emulsions and ultimately emulsion polsrmers is dependent on the comonomers in copolymers of acryUc and methacryUc acids. This transition from water-soluble polymer to emulsion polymer as the acidic monomer is decreased depends on the hydrophobicity of the comonomer. Introduction of divinyl monomers causes transition to gel materials in all compositions. The gels may vary from highly swollen to tightly bound copolymers, depending on the cross-linker level. 

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