Integrierte Vermeidung und Verminderung der Umweltverschmutzung

Chapter 3
3.2.13.3 Solid output
Filter residues arise and require a suitable method of recovery or disposal, e.g. bleaching earth
in edible oil refining or diatomaceous earth in a brewery.
3.2.13.4 Energy
Pumping requires electrical energy.
3.2.14 Membrane separation (C.6)
3.2.14.1 Water
Water is used periodically to clean the separation equipment. The frequency of cleaning and the
volumes of water used vary depending on the product and equipment. Waste water is produced
from washing as well as in the form of separated waste products from the process, and contains
dissolved organic material and SS.
3.2.14.2 Energy
Membrane separation is a pressure driven process, so electrical energy is required. In
electrodialysis, electrical energy is required for the transport of ions.
3.2.15 Crystallisation (C.7)
3.2.15.1 Water
In crystallisation operations, water is used for cooling and is normally recirculated. Depending
on the cooling requirements, water is recirculated via chilling units, cooling towers or cooling
ponds. Waste water containing soluble organic material is generated after the removal of
crystals.
3.2.15.2 Solid output
In the refinery process, active carbon is used if required. Spent active carbon is either
regenerated or disposed of as waste.
3.2.15.3 Energy
Electricity is needed to power the pumps and drives. Energy is needed for the cooling system.
3.2.16 Removal of free fatty acids by neutralisation (C.8)
3.2.16.1 Water
The neutralisation process requires cooling water. The waste water that results from a combined
neutralisation and soap-stock splitting has a temperature of about 100 °C, high acidity and
contains salts of sodium sulphate or sodium chloride and sodium phosphate in high
concentrations. If citric acid is used, this increases the BOD load of the waste water. The
disposal of process waste water with high concentrations of sulphates (>2000 mg/l) into a
MWWTP may cause corrosion of the concrete. Phoshorus levels may be high. The waste water
may also contain FOG.
3.2.16.2 Air emissions
The soap-stock acidulation system may be a source of odour.
130 January 2006 RHC/EIPPCB/FDM_BREF_FINAL