Integrierte Vermeidung und Verminderung der Umweltverschmutzung

LIQUID WASTE
IN
VOLUME/WEIGHT
0.7 a -5 m 3 /t
POLLUTING
LOAD
COMPOSITION
*BOD: 20000 - 35000 mg/l
*COD: 30.000 - 60000 mg/l
*Oils & fats: 5000 - 10000 mg/l
*Organic N: 500 - 800 mg/l
a Polyphenols: 80000 mg/l
TSS: 20000 mg/l
COD: 200000 mg/l
pH: 3 - 5.9
WASTE
WATER
Waste water
Waste water
VEGETABLE OIL
PRODUCTION
Cleaning / Storage
Hulling b
Breaking/Flaking/
Crushing
Cooking/
Conditioning
Pressing /
Centrifugation
Solvent extraction
Crude oil
Degumming
Neutralisation
Bleaching
Deodorisation c
Refined oil
Stalks
Leaves
Stones, sand
Hulls
Hulls
Chapter 3
RHC/EIPPCB/FDM_BREF_FINAL January 2006 183
Dust
Gums
SOLID WASTE/
BY-PRODUCT
Crude cake
Olive stones a
Extracted cake or
spent meal b
Soapstock
Spent
bleaching earth
Distillate
% SOLID
WASTE IN
WEIGHT
5 a
33 a -59
0.4 - 2
0.5 - 5
TOTAL: 40 - 70
a For olive oil production.
b For rape seed oil production, hulling is not applied. The solvent extraction is the step from which the main solid waste is generated.
c Most of the water is generated during deodorization, in the case of rape seed oil, the amount can be three times as much as waste water
from raw oil production.
Figure 3.10: Types and quantities of wastes and by-products generated in vegetable oil processing
[134, AWARENET, 2002]
3.3.4.4.1 Oilseed
Typically the yield from oilseed processing is almost 100 %. Products from oilseed processing
and vegetable oil refining are mainly vegetable oil, protein rich meal, lecithin and ffa (acid oil).
Ffa may contain tocopherol, a natural antioxidant. They can be used as a feedstock for the
production of vitamin E. By-products may either be used as animal feed or burnt as fuels [182,
Germany, 2003, 185, CIAA-FEDIOL, 2004].
Chemical refining produces soap stock during the neutralisation of crude oil. This consists
mainly of the sodium salts of the separated ffa, but also includes triacylglycerols, phosphatides,
proteins, pigments and other compounds. Normally soap stock is further processed in the
refinery by splitting the soaps and regaining the ffa. It is possible to mix the soap stock from the
chemical refining of vegetable oil with other ingredients to produce low quality soaps or for use
in meal for animal feed [182, Germany, 2003, 185, CIAA-FEDIOL, 2004].
Crude cake and spent meal are either incinerated or used in the production of fuels and other
products such as kernel oil and activated carbon. They can also be used in animal feed.
Exhausted cake, which has an oil content lower than 1 %, is usually formed into pellets or
briquettes and its main application is animal feed, but it may also be composted or burnt.
Lecithin is an edible by-product consisting of a mixture of phosphatides with minor quantities
of glycolipids and oligosaccharides. It is known to have outstanding functional characteristics,
such as emulsification properties, spreadability and wetting ability. After a very simple and
inexpensive purification, it can be used in a number of applications in food, cosmetics and
pharmaceuticals. Soybean oil is the most important source of lecithin, although other vegetable
oils such as maize, sunflower or ground-nut oil also yield suitable lecithin.