High Vacuum Purge and Vapor Canister Performance

High vacuum purge enhances the performance of an automotive vapor canister by increasing working capacity and decreasing Diurnal Breathing Loss (DBL) emissions. These improvements are significant because high vacuum purge can potentially be adapted for use in an automotive evaporative emissions system. These benefits were demonstrated by conducting multiple aging cycles at ambient, low, medium, and high vacuum levels. Effects on gasoline working capacity, butane capacity, accumulated hydrocarbon heel, and DBL performance were then compared and discussed.