A Novel Vapor-Phase Process for Deep Desulfurization of Naphtha/Diesel

Abstract

Tier 2 regulations issued by the U.S. Environmental Protection Agency (EPA) require a substantial reduction in the sulfur content of gasoline. Similar regulations have been enacted for the sulfur level in on-road diesel and recently off-road diesel. The removal of this sulfur with existing and installed technology faces technical and economic challenges. These challenges created the opportunity for new emerging technologies. Research Triangle Institute (RTI) with subcontract support from Kellogg Brown & Root, Inc., (KBR) used this opportunity to develop RTI's transport reactor naphtha desulfurization (TReND) process. Starting with a simple conceptual process design and some laboratory results that showed promise, RTI initiated an accelerated research program for sorbent development, process development, and marketing and commercialization. Sorbent development has resulted in the identification of an active and attrition resistant sorbent that has been prepared in commercial equipment in 100 lb batches. Process development has demonstrated both the sulfur removal performance and regeneration potential of this sorbent. Process development has scaled up testing from small laboratory to pilot plant transport reactor testing. Testing in the transport reactor pilot plant has demonstrated the attrition resistance, selective sulfur removal activity, and regeneration activity of this sorbent material. Marketing and commercialization activities have shown with the existing information that the process has significant capital and operating cost benefits over existing and other emerging technologies. The market assessment and analysis provided valuable feedback about the testing and performance requirements for the technical development program. This market analysis also provided a list of potential candidates for hosting a demonstration unit. Although the narrow window of opportunity generated by the new sulfur regulations and the conservative nature of the refining industry slowed progress of the demonstration unit, negotiations with potential partners are proceeding for commercialization of this process.v Sulfur speciation of feed and product naphtha samples 4-4 4-5Effects of hydrogen pretreatment on desulfurization performance of NWA 4-5 4-6 GC chromatograms of the feed and product samples for FCC naphtha multicycle testing in PTR system 4-6 4-7Chromatograms of hydrtreated diesel feed and product effluent with RTI's coprecipitated spray dried sorbents 4-7 4-8Liquid product sulfur concentrations during parametric testing of active component content 4-8 4-9Liquid product sulfur concentrations for parametric testing of sorbent support composition 4-9 4-10 Liquid sulfur product concentrations for multicycle test with RTI-2 4-10 4-11 Effluent sulfur concentration during product collection for product specification analysis 4-11 4-12 ASTM D86 distillation curves for hydrotreated diesel feed and product 4-11 4-13 Sulfur concentration for cumulative liquid product during multicycle testing at 30 and 100 psig 4-13 4-14 ...