Evaluating the vapour evaporation from the surface of pure organic solvents and their mixtures

Abstract

Some perfumery and cosmetic products represent mixtures and they include large parts of solvents as ethanol, water, acetone and isopropyl alcohol. Solvents as pure hexane and ethanol-water mix­tures are used in the solvent extraction of oil-bearing plant materials and herbs. The goal of this study was the emissions of volatile solvents released during above pointed productions to be evaluated. It was found that the specific evaporation rate varies from 1.2 kg/(m2.h) (for pure methoxy-propanol) to 66 kg/(m2.h) (for three-com­ponent mixture including acetone). The eva­poration rate is higher for solvents with higher vapour pressure and at a higher velocity of surrounding air. The evaporation is less intensive from pure solvents than their mixtures. The time for the eva­po­ration from a film of solvents and their mixtures was also evaluated. It varies from 10 s (for isopropyl alcohol) to 9 min (for methoxy-propanol).Practical applicationsThe evaluation of volatile solvent emissions is a mandatory step in the design of plants for manufacturing perfumery, cosmetics, deriving essential and edible oils by means of organic solvents. Most of volatile organic solvents used are highly flammable and healthy hazardous. For assuring fire safety and safety-health working conditions and environment the ventilation system must be designed on the base of this emission evaluated. The obtained results were applied for plant design of the company “Star Nails Bulgaria” Ltd. Plovdiv.