Detergent powder
Detergent powder manufacture has some specific environmental issues associated with it that
are not present in other areas of the industry. These are dust control and volatile organic
emissions. Dust present during delivery and transfer of bulk powdered detergent (and
powdered raw materials) is a potential problem. Dry and wet cyclones are used to filter out
most of the dust, and all emissions are monitored. If the dust level in these does exceed
acceptable limits, appropriate remedial action is taken. Dust levels in emissions must be kept
below 50 mg m-3.
The spray drying tower also releases volatile organics. These emissions are minimised by
having tight specifications on what can be added as primary detergent active material. Any
potentially hazardous material is added with the secondary actives after the tower so that it is
not heated. Spot checks are done on the total hydrocarbon content of the exhaust gases using
a flame ionisation detector.