Process Modification

Chemical and petroleum industries have changed dramatically by implementing automated operations, computerized process control, and completely enclosed systems that minimize the release of materials to the outside environment.

A process modification example is industry reducing the oxidation of SO2 to SO3 by reducing excess air from ~20% to <1% when burning coal, resulting in reduced sulfuric acid emissions. However, this process change has increased fly ash production.

Powders and granulated solids are widely used in industry. Handling these materials at locations such as transfer points or bagging and dumping operations generates dust that can affect worker health. Plinke et al. (1991) found that the amount of dust generated by an industrial process depends on the size distribution of the dust, the ratio of impaction forces that disperse the dust during material handling, and the cohesion properties of the dust, such as moisture content. The implication is that by modifying both the material handling processes and the properties of the powders, the dust generated can be reduced.

Similar approaches are being used in municipal trash incinerators which emit carcinogenic dioxins. By adjusting the temperature of incineration, dioxin emissions can be prevented.

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