A cost benefit analysis of the ultrasound-assisted oxidative desulfurization (UAOD) continuous-flow process in organic sulfur removal from pyrolysis oil was carried out. Two separate studies using one and two UAOD units were compared by cost and percentage of sulfur removal. The desulfurization cost for a single UAOD unit was calculated at $0.70/gal with sulfur removal of 68%, whereas the cost and removal percentage were $1.39/gal and 90.91%, respectively, for two UAOD units connected in a series. The monetary value of the health benefits was around $466.59/d for one unit and $623.78/d for two units. Moreover, the best gross income for desulfurized pyrolysis oil after the UAOD system was $1916.46/ d in Taiwan. Economic and risk evaluations demonstrated that pyrolysis oil desulfurization using one set of UAOD continuous-flow units can provide full benefits and has few environmental or health impacts. (C) 2012 Elsevier Ltd. All rights reserved.
