焦炭气化对接触裂化催化剂物化性能的影响

采用BET、XRD、TEM、SEM、XRF技术对挂焦失活、以氧气/水蒸气混合气体气化部分焦炭后的接触裂化催化剂进行物化表征。结果表明，接触剂挂焦失活后，比表面积和孔体积明显下降；气化部分焦炭后，比表面积和孔体积开始回升。大多数焦炭存在于接触剂上孔径大于2 nm的孔道内。接触剂长时间经历高温、水热环境后，沸石组分和基质均遭受到不同程度的破坏。在气化接触剂上焦炭的过程中，接触剂上硫、氯含量大幅度减少，其他元素的含量无明显变化。焦炭层能够降低气化过程中水蒸气对接触剂的破坏作用。气化结束后接触剂上焦炭含量越高，气化过程中接触剂受到水热破坏作用的影响越小。

Effect of Coke Gasification on Physicochemical Performance of Contact Materials

The contact materials firstly coked and then gasified to remove some deposited coke with gaseous mixture of oxygen and steam were characterized by different methods, such as the nitrogen dsorption-desorption analysis (BET), the X-ray diffraction (XRD), the transmission electron microscopy (TEM), the scanning electron microscopy (SEM), the X-ray fluorescence analysis (XRF). The results demonstrated that the specific surface area and pore volume of the contact materials were both heavily decreased when the contact materials were coked, and both of them became larger when partial gasification of deposited coke on the contact materials was carried out. It is inferred that coke was mostly deposited in contact materials pores of diameter larger than 2 nm. The exposure of high temperature and hydrothermal environment caused the microstructure destruction for both the zeolites and matrix in contact materials. During the partial gasification the content of sulfur and chlorine on contact materials were both substantially decreased, while the contents of other elements were not changed. The coke layer prevented contact materials from hydrothermal destruction, and the more remained coke on contact materials after partial gasification, the more the protective ability of contact materials during gasification.