流化催化裂化汽油加氢改质催化剂积炭失活行为研究

生产低硫、低烯烃和高辛烷值的清洁汽油,是国家保持能源经济可持续发展的必然要求。对反应前后两种全馏分流化催化裂化加氢改质催化剂进行了X射线衍射(XRD)、傅立叶红外光谱(FT-IR)、热重-差热分析(TG-DTA)表征,发现由于积炭物种的干扰,两种催化剂的XRD特征峰强度均明显减弱,两种催化剂上的积炭均由脂肪族烃类和芳香族烃类组成,其中芳构化催化剂的积炭进入到分子筛的孔道内部。TG-DTA分析结果表明,运转660h后,脱硫催化剂积炭量为8.0%(质量分数),失重峰的峰温为490℃,芳构化催化剂积炭量为20.5%(质量分数),容碳能力大,失重峰的峰温为530℃。两步法改质工艺用于全馏分催化裂化汽油加氢改质评价660h。反应后,硫含量从242μg/g降到73μg/g,加氢脱硫率为70%;烯烃含量从36.8%(体积分数)降到24.9%(体积分数),降烯烃率为32%;芳烃含量从18.9%(体积分数)升到19.9%(体积分数);辛烷值损失1.6个单位。

A Study on the Deactivation of FCC Gasoline Hydro-upgrading Catalyst due to Coke Formation

It is a path that a country has to take to produce low-sulfur,low-olefin,and high-octane clean gasoline products in order to push its energy economy to grow in a sustainable manner.Researchers characterized two full-range FCC gasoline hydro-upgrading catalysts before and after reaction,using the XRD,FT-IR,and TG-DTA techniques.Due to the interference of carbon deposit species,the intensities of the XRD characteristic peaks of both catalysts decreased considerably.The carbon deposited on both catalysts consists of aliphatic hydrocarbons and aromatic hydrocarbons and the carbon on the aromatization catalyst entered into the pores of the molecular sieve.The results of the TG-DTA analysis showed that after 660 hours of operation,the coke deposited on the desulfurization catalyst was 8.0%（by mass fraction）,the temperature of the agravic peak was 490℃,the coke deposited on the aromatization catalyst was 20.5%（by mass fraction）,the catalyst had relatively high capacity to accommodate carbon,and that the temperature of the agravic peak of the catalyst was 530℃.The two-step upgrading technique was used in the assessment of the hydro-upgrading of full-range FCC gasoline for 660 hours.After reaction,the sulfur content dropped to 73μg/g from 242μg/g,with the hydrodesulfurization rate standing at 70 %, the olefin content dropped to 24.9%（by volume fraction） from36.8%（by volume fraction）,with the olefin reduction rate standing at 32%,the aromatic hydrocarbon content rose to 19.9%（by volume fraction） from 18.9%（by volume fraction）,and the RON dropped by 1.6.