Integrated Technology Of Producing Lube Base Oil And High Quality Diesel Oil From Syngas

In this article, we successfully prepared the Co/Zr/SiO2 catalyst for Fischer-Tropsch synthesis which had higher activation, long life-span and heavy hydrocarbons selectivity after we systemically studied the catalyst preparation techniques such as metal impregnation sequence, active metal loading amount, additive and additive loading amount.Co/SiO2 catalysts for F-T synthesis were characterized by using BET,TPR,XRD and EXAFS techniques. (1)BET indicated that when using larger pore diameter SiO2 as carrier, both the larger pore diameter support and the addition of Zr improved the stability and activity of the catalyst since interaction between Co and SiO2 was less. But the influence of addition of Zr on hydrocarbon product distribution was different from that of larger pore diameter support. (2)For Cobalt-based catalysts for F-T synthesis which were prepared by dip method, the best amount of Co is 10%～20%,or else decreasing the activity and selectivity of catalysts.(3)Higher selectivity of heavy hydrocarbons and Co-Zr interface had better corresponding relation, Zr was in monolayer dispersion state on carrier surface and made interaction of Co-Si weaken.(4)When examining different additive promotion functions to catalysts for F-T synthesis,additive could be classified as hydrocarbons structure additive, electron additive and Co-type additive by different functions of additive to F-T synthesis reaction.(5)TPR results revealed that reduction of Co/ZrO2/SiO2 catalysts was divided into two steps under the best reduction temperature of 673K: Co3O4 CoO Co. In addition, The F-T synthesis process conditions were examined on the 200ml fixed-bed reactor, and it was found that CO conversion was 95.5%, CH4 selectivity was 7.92%, C5+ hydrocarbon selectivity was 88.35%, and C20+ hydrocarbon selectivity was 45.2% under the best operating conditions:temperature of 200℃, pressure of 3.0MPa, volume space velocity of 500h-1, hydrogen CO volume ratio of 2.0. According to above test, the 500 hours stability test of said prepared Co/Zr/SiO2 catalysts for F-T synthesis were also measured. The results of the evaluation were CO conversion of 85%, CH4 selectivity of 12%, C5+ hydrocarbon selectivity of 83%, and C20+ liquid hydrocarbon selectivity of 45%.