Design and Evaluation of an onboard refueling vapor recovery system for scooter

This paper presents the development of a novel onboard refueling vapor recovery (ORVR) system specifically designed for scooters. The study evaluates the system's feasibility and its performance in reducing evaporative emissions, with the aim of contributing to the advancement of practical and cost-effective ORVR solutions in Taiwan. An initial literature review compares the evaporative emission performance of vehicle-mounted ORVR systems with Stage II vapor recovery systems installed at fuel stations. Findings indicate that ORVR technology offers superior controllability and lower implementation costs. A prototype ORVR system for scooters was developed, comprising a custom-designed fuel tank, carbon canister, vapor pipe, fuel limit vent valve, and surge protector. The self-fabricated carbon canister demonstrated sufficient vapor storage capacity to undergo diurnal and hot soak adsorption tests over a period of three consecutive days. The study further analyzes and compares the motorcycle evaporative emission test methods used in Taiwan with those adopted in the United States for ORVR systems. This system is capable of regulating both the desorption of the activated carbon canister and negative pressure vapor recovery during refueling under optimal engine conditions. In conclusion, the results of the ORVR refueling test indicate a 96.3 % reduction in vapor emissions compared to the evaporative emission control system of original equipment manufacturer. This significant improvement underscores the effectiveness of ORVR systems in capturing fuel vapors during refueling, thereby reducing environmental pollution and enhancing fuel efficiency. The developed system serves as a valuable reference for future efforts aimed at designing economical and effective ORVR solutions for two-wheeled vehicles.