Upgrading Fischer-Tropsch naphtha.

摘要

Reforming of Fischer-Tropsch (F-T) naphtha was studied. This report documents a pilot plant study, and its translation into economic evaluations of various alternatives for upgrading F-T naphtha into a high-octane gasoline blending stock. There is a significant economic advantage to reform naphtha at low pressure (50 psig) as opposed to high pressure (125 psig). This is particularly true for the extremely lean naphtha produced by F-T synthesis. For the case of a 40,000 BPD unit processing a full-boiling range (FBR) Arge naphtha, an additional 5.4 vol % yield is obtained at low pressure. This translates into 767,000 bbl of additional reformate over the course of a year. Process economics are closely related to liquid product yield, and the additional reformate yield of the 50 psig operation adds over $29,000/day to the gross margin. Although the low pressure unit has a larger catalyst regenerator (more capital) and has a higher utility consumption, the after-tax IRR increases by a factor of 1.3 as pressure is reduced from 125 to 50 psig because of the yield advantage. Two naphtha upgrading process flow schemes are evaluated in this report. Low pressure reforming of the FBR naphtha is compared to a split-naphtha scheme where light and heavy naphtha is processed separately, so as to maximize yield. 9 refs., 21 figs., 22 tabs.