DOT-300重整油脱烯烃催化剂工业试验

Industrial Application of a Catalyst for Olefin Removal from DOT-300 Reformate

中国石油化工股份有限公司茂名分公司的重整生成油脱烯烃装置原使用改性白土时,存在周期使用寿命短、频繁更换和二甲苯产品质量波动大等问题。使用以MWW结构的纳米层状分子筛为活性组分开发的DOT-300催化剂后,表现出优异的深度脱烯烃性能、长周期稳定性和耐高非芳烯含量原料等特点,二甲苯产品质量好。在20多个月的运行期间,原料的溴指数为700~1 600 mg-Br/100 g、非芳烃含量最高为0.96%,在质量空速为4.1h^(-1)、温度为178~193℃条件下,DOT-300催化剂床出口物料的溴指数稳定为30~110 mg-Br/100 g,二甲苯产品溴指数低于14 mg-Br/100 g,稳定期C_(8)芳烃中甲苯含量为0.05%~0.15%。因原料的非芳烃含量指标放宽至2.5%,脱庚烷塔蒸汽消耗量从改性白土工况的平均16.62t/h减少至使用DOT-300后的平均12.58t/h。纳米层状分子筛特殊的二维薄层状结构及处于十二元环空穴的开放活性中心,是DOT-300脱烯烃催化剂具有优异综合性能的关键原因。

Severe technical challenges, such as short lifetime, frequent discharge of deactivated clay, and quality fluctuation of CA product, had been encountered when modified clay was originally used to remove the olefin compounds in reformate in SINOPEC Maoming Company. After using DOT-300 catalyst developed based on MWW structure nano-lamellar molecular sieve as the active component, it showed excellent deep olefin removal performance, long-term stability and good tolerance to raw materials with high non-aromatics content, and the quality of xylene products was good. During the operation period of more than 20 months, the bromine index (BI) of raw materials was 700-1 600 mg-Br/100 g, and the maximum content of non-aromatics was 0.96%. Under the conditions of mass space velocity of 4.1 h^(-1) and temperature of 178-193 ℃, BI of effluent from the DOT-300 catalyst bed was in 30-110 mg-Br/100 g, BI of xylene product was lower than 14 mg-Br/100 g, and the toluene content in C_(8) aromatic was 0.05%-0.15% in the stable stage. The steam consumption in de-heptane tower was reduced from an average of 16.62 t/h under clay mode to an average of 12.58 t/h after using DOT-300 catalyst. The outstanding performance of DOT-300 de-olefin catalyst can be ascribed to the two-dimensional morphology and abundant active sites in 12MR cups of the MWW type nano-lamellar molecular sieves.