Treatment of odours from the processes of saponification of soybean residues
Some Bolivian industries use solid waste from the refining of soybean oil (soybean wastes) in their laundry soap manufacturing processes, due to its high fat content (30-60%). However, in the saponification stage, considerable amounts of offensive odors (mainly ammoniacal) are produced, which are evacuated to the surrounding neighborhood, causing a significant negative environmental impact.
As an alternative solution to this problem, a laboratory study is presented on the development of a hybrid system for the treatment of odors from saponification processes of soybeans. The system consists of an ammoniacal gas absorber followed by a contact tank between nebulized essential oils and the remaining gases from the absorption process.
Several samples of the soybean residues obtained from national suppliers and the gases generated in the saponification were physically and chemically characterized. Then numerous experimental runs were carried out to test the effectiveness of three treatment systems designed and built in the laboratory: A closed system that allowed the characterization of the vapors and the establishment of essences dosage relationships based on the concentration of odors; a contact system between nebulized essences and smelly gases and the mentioned hybrid system.
Untreated gases have as main components volatile organic compounds (VOC’s) soluble and non-soluble, ammonia and carbon dioxide. Soybean residues with higher residual protein content give off greater amounts of free ammonia. Reliable relationships have been established between the doses of nebulized essential oils and the concentration of VOC’s and the Minimum Detectable Odor Threshold (MDOT). The head product of eucalyptus oil is the most effective and economical essence for the treatment of odors generated by the three types of soybeans tested. It was possible to eliminate the perception of unpleasant odors generated in the saponification processes using the hybrid system that proved to be the most efficient. The experimental methods and devices used in the study can be used for similar investigations into odor problems that the various local and national industries currently have.
Responsible:
Ramiro Escalera Vázquez, Ph. D.
E-mail: rescalera@upb.edu
Researchers:
Ramiro Escalera, Ph. D.
Ariel Baldivieso,Ing.
Claudia Villegas, Ing.
Marianela Cavero, Ing.
References about the project: Director CIPI rescalera@upb.edu
