渣油悬浮床加氢裂化及热转化产物氮分布的比较

COMPARISON OF NITROGEN DISTRIBUTION IN SLURRY-BED HYDROCRACKING AND THERMAL CONVERSION OF RESIDUES

选用克拉玛依常压渣油为原料 ,在 5 0 0ml高压釜内于分散型催化剂存在下进行悬浮床加氢反应 ,初始氢气压力 7.0MPa ,反应温度分别为 4 30℃、4 35℃和 4 4 0℃ ,反应时间 1h ,催化剂用量为 80 0 μg/ g。在同样的反应温度和时间条件下进行热反应。两种工艺的反应产物经常减压蒸馏 ,切割馏分范围为IBP～ 180℃、180～ 36 0℃、36 0～ 5 0 0℃和 5 0 0℃以上 ,采用非水电位滴定法测定各馏分的碱性氮含量 ,用化学发光定氮法测定各馏分的总氮含量。结果表明 ,两种反应工艺的产物中 ,各馏分的碱性氮、总氮含量均随反应温度的升高而升高。悬浮床加氢比热转化工艺更易于生成重馏分油 ,也利于含氮化合物的裂化转化。悬浮床加氢中分散型催化剂和氢气的存在有促进含氮化合物裂化转化的能力。

The atmospheric residue from Kalamayi Refinery was hydrocracked in a 500 ml batch autocalve in the presence of a dispersed catalyst. The reaction was conducted at temperatures of 430°C, 435°C, or 440°C, residence time of 1 h, catalyst content of 800 μg/g (based on metal in feed), and initial hydrogen pressure of 7.0 MPa in a slurry-bed. It was also thermally cracked in the same batch autoclave, with the same reaction temperature and time as those of the slurry-bed. The reaction products were separated into four fractions of IBP-180°C, 180-360°C, 360-500°C and ≥ 500°C. The basic nitrogen in each fraction was determined by nonaqueous titration. The total nitrogen was determined by chemical illumination method. Compared with the nitrogen distribution of thermal conversion products, both the basic and the total nitrogen in products from the slurry-bed hydrogenation increased with the increase of the reaction temperature. The presence of dispersed catalyst, coexisting with hydrogen in the slurry-bed hydrogenation reaction system, promoted the conversion of nitrogen compounds in the feed obviously.