Towards Clean Fuels:Molecular-Level Sulfur Reactivity in Heavy Oils

摘要

Due to environmental concerns there is a continual worldwide thrust towards clean transportation fuels,with the emphasis on minimization of sulfur content.The threshold limit for sulfur in gasoline and diesel is expected to be regulated to 50 ppm of weight (ppmw)or less within the next few years,several billion dollars are anticipated to be spent to meet these stricter regulations. Sulfur removal from heavy oil (HO)is an important process for meeting sulfur regulations in transportation fuels.From an economic viewpoint,it is therefore extremely desirable to increase the efficiency of the HO sulfur removal process.Unfortunately,whereas there is a vast and fundamental understanding of sulfur removal chemistry for gasoline/diesel,the molecular-level understanding of the ultra-complex HO desulfur-ization chemistry is inadequate,thereby limiting process/catalyst improvements.Because of its enormous complexity,previous studies have been unable to provide the much needed quantitative molecular-level structure-reactivity information about HO sulfur chemistry.