用芳构化增强的反应吸附剂对催化裂化汽油改质的实验研究

用固相混捏法制备了耦合芳构化功能的反应吸附脱硫催化剂,研究了该催化剂对FCC汽油的改质性能。采用XRD和Py-IR表征了吸附剂的晶体结构和酸性特征,在高压微反装置上对其进行了活性评价,研究了吸附剂组成与工艺条件对FCC汽油改质的影响,结果表明:制备的吸附剂的活性组分由结晶良好的ZnO和ZSM-5分子筛及Ni活性组分构成。随着吸附剂中HZSM-5含量的增加,吸附剂酸性增强,芳构化反应功能提高。工艺条件对FCC汽油改质影响的研究表明,升高温度有利于芳构化反应的进行,但会加速催化剂的结焦失活,影响吸附剂的脱硫效果;增加压力可以使反应中的氢分压升高,减缓吸附剂的失活,有利于反应吸附脱硫,但不利于芳构化反应;增加氢油比可以抑制生焦,保持吸附剂活性,有利于反应吸附脱硫和芳构化反应,但会造成氢耗增加和烯烃饱和;空速增加可提高处理量,但由于原料与吸附剂的接触时间减少,导致反应物分子不能充分与吸附剂上的活性位反应,不利于芳构化和反应吸附脱硫反应的进行。采用研制的芳构化增强的反应吸附脱硫工艺及其吸附剂处理胜华FCC汽油的结果表明,在反应温度为425℃,反应压力为1.0 MPa,氢油比为200∶1,反应空速为6 h-1条件下,达到产物硫质量分数10μg/g以下时,异构烷烃和芳烃含量明显提高,可以较好的保持汽油辛烷值。

Demonstration experiment study on upgrading FCC gasoline by using aromatization-enhanced reaction adsorbent

The preparation tion （RADS） by solid kneading of the adsorbents for aromatization-enhanced reactive adsorption desulfuriza- method and the performance of FCC gasoline upgrading were investigated. XRD, Py-IR were used to determine the crystal structure and acid feature. The activity of adsorbents was eval- uated in a fixed bed reactor, and the impacts of adsorbent compositions and the process conditions on the per- formances of FCC gasoline upgrading were studied. It is found that the active components of the adsorbent are composed of well crystallized ZnO, ZSM-5 zeolite and the active Ni. The acidity of adsorbents increases with the increase of HZSM-5 content, which is beneficial for aromatization. The study of process conditions＇ impact shows that high temperature is favorable for aromatization reaction but accelerates catalyst＇ s coking and deacti- vation, thus reducing the desulfurization performance of the adsorbent. High pressure can raise hydrogen par- tial pressure and mitigate absorbent deactivation, which is favorable for reactive adsorption desulfurization but not beneficial to aromatization. Higher H2/Oil ratio can inhibit the adsorbent coking and maintain the activity, which is favorable to improve the desulfurization performance and aromatization performance. But the hydrogen C0nsumption will be increased and olefins will be saturated. The higher liquid hourly space velocity （LHSV） increases the treatment capacity but decreases the contact time between reactants and adsorbents, which is not favorable for reactive adsorption desulfurization and aromatization because of in-sufficient reaction of reactant with the active sites of absorbent. The treatment of Shenhua FCC gasoline by aromatization-enhanced reactive adsorption desulfurization process and catalyst has shown that, under the conditions of reactive temperature of 425 ℃, total pressure of 1.0 MPa, H2/Oil ratio of 200： 1, LHSV of 6 h^-1 the sulfur content of 10 ppm, the isoparaffin and aromatic contents are obviously increased and a good gasoline octane number is maintained.