氮对催化裂化汽油中烯烃加氢饱和反应的影响

EFFECT OF NITROGEN COMPOUNDS ON THE HYDROGENATION OF OLEFIN SATURATION IN FCC NAPHTHA

采用硅胶吸附脱除原料中氮化物,得到氮含量不同而硫含量及烃类组成基本相同的4种催化裂化汽油原料。为了考察氮化物对催化裂化汽油选择性加氢脱硫过程烯烃加氢饱和反应(HYDO)的影响,在反应温度285℃、氢分压1.6MPa、体积空速4.0h^(-1)及氢油体积比400的条件下,采用 Co-Mo/Al_2O_3催化剂在中型固定床试验装置上进行了4种催化裂化汽油原料选择性加氢脱硫试验。结果表明,在催化裂化汽油选择性加氢脱硫过程中,氮化物对 HYDO 有明显的抑制作用;对直链烯烃和环烯烃加氢饱和反应抑制作用明显,但对支链烯烃加氢饱和反应抑制作用较小。对于硫含量和烃类组成相同的原料,在烯烃饱和率相同时,氮含量较高的原料加氢产物研究法辛烷值损失比氮含量较低的原料加氧产物研究法辛烷值损失小。

Using silica gel to remove nitrogen compounds in FCC naphtha, four feeds having various nitrogen contents and the same hydrocarbon compositions and sulfur content were obtained. During the selective HDS treatment of these four FCC naphtha feeds, the effect of nitrogen compounds on the hydrogenation of olefin saturation （HYDO）was studied in a fixed-bed pilot plant over a commercial CoMo/Al2O3 catalyst, under the conditions of a reaction temperature of 285 ℃ ,a hydrogen partial pressure of 1.6 MPa,a LHSV of 4.0 h^-1 and a H2/oil volume ratio of 400. Results showed that during the selective HDS process, nitrogen compounds could inhibit the HYDO reactions, and the inhibition on linear olefins and cyclic olefins was more significant than that on branched olefins. With the same olefin saturation rate,the RON loss of product from feed having higher nitrogen content was less than that from feed having lower nitrogen content.