Integrierte Vermeidung und Verminderung der Umweltverschmutzung

Chapter 3
3.2.18.5 Noise
Noise issues may arise from the cooling tower fans.
3.2.19 Decolourisation (C.11)
3.2.19.1 Water
During start-up and shut-down, low volumes of aqueous product may be discharged which
contain low quantities of solid matter. In some cases this discharge is reprocessed/re-used in the
process. However, it is not always economical to concentrate this material, in which case it is
discharged as waste water. This waste water may contain dissolved organic material, SS and
dissolved solids.
3.2.19.2 Solid output
The decolourisation process produces a filter residue consisting of the active material, any filter
aid used and some residual product. This solid output is sometimes sent to landfill or for
landspreading/composting depending on its nature. Depending on the type of process/product,
this solid output can also be used as animal feed.
3.2.19.3 Energy
Any heating of the product used to meet the optimum conditions for the operation can usually
be recovered by normal heat recovery systems. The regeneration of activated carbon involves
kilning at elevated temperatures in the absence of oxygen. This is mainly done off site by
specialised companies.
3.2.20 Distillation (C.12)
3.2.20.1 Water
A residual liquid such as stillage, pot ale, spent lees and spent wash, is discharged from the
stills. The waste water contains SS and very high BOD levels. Where recovery systems exist, a
proportion of the stillage may be re-used.
3.2.20.2 Air emissions
Emissions to air include dust, VOCs and odour. There may be minor emissions of
uncondensable volatiles, mainly carbon dioxide and ethanol from column stills. There are no
issues for pot stills.
3.2.20.3 Solid output
Concentrated stillage or dried stillage may be used in animal feed, as a feedstock in sugar and
grain-based production, sent for landspreading or otherwise disposed of as waste. Solid outputs
are also used for methane production, the gas being used for energy production. This can
improve the energy balance in the distillation process.
3.2.20.4 Energy
The distillation tower is heated by steam. For pot stills, 12 to 13 kWh per litre of pure alcohol is
required.
132 January 2006 RHC/EIPPCB/FDM_BREF_FINAL