The experimentation confirms the feasibility and the efficiency of the SC CO(2) on wool scouring sludge. With the best conditions, on a half industrial unit (pressure 250 bars, temperature 80øC, solvent ratio 56 and 2% methanol), it will be possible to extract about 70% of wool grease and about 80% of pesticides.
In the present state of the legislation, the viability is not demonstrated for the treatment of wool scouring sludge but the situation could evolve in the future and the SC CO(2) -SCWO process could be competitive.
In contrary, best hope can be found for the treatment of wool grease or lanolin because it is possible to treat grease in a continuous way with a lower solvent ratio. The efficiency of the CO(2) is higher than steam stripping particularly on pyrethroids compounds. Odour is removed and colour does not change.
CO(2) treatment has been evaluated in comparison with other possibilities to remove wool scouring sludge.
The treatment of wool scouring effluents brings about a large quantity of mud hose
er to controlled dumping sites is being hit by important taxes that may jeopardize the very existence of this scouring process in Europe. These mud effluents contain, in fact, a large quantity of wool grease, which itself contains some amounts of pesticides temming from the treatment of sheep. Because of the presence of these impurities mentioned above, the disposal of this mud onto agricultural land, either as compost or directly has run into conflicts due to strict and constraining legislation. The incineration of these sub products would be costly, due to the large volumes which
te of inert material contained in them. The aim of this project is the study of extraction possibilities, with supercritic C02, for the extraction of fatty material as well as the removal and separation of pesticides from the extracted fatty materials. The pesticides will then be destroyed by oxidation in water in supercritic conditions. The process stems from modern non polluting technology considered as efficient in the extraction and separation of hydrophobic compounds. The suggested techniques will be evaluated in relation to other extraction processes using solvents. Other means of valorisation, instead of the agricultural strategy will also be tested (for ex. the use in building materials).
Funding SchemeCSC - Cost-sharing contracts