Wang Xinxing, Lin Tiejun, Li Jie, Yu Fei, Lv Dong, Qi Xingzhen, Wang Hui, Zhong Liangshu, Sun Yuhan
CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences Shanghai 201203 P. R. China
University of the Chinese Academy of Sciences Beijing 100049 P. R. China.
RSC Adv. 2019 Jan 30;9(8):4131-4139. doi: 10.1039/c8ra10477h.
Direct production of olefins syngas conversion over a CoC-based catalyst was investigated in a slurry bed reactor (SBR). It was found that the total selectivities to olefins and oxygenates reached 88.8C% at a CO conversion of 29.5% at 250 °C, 5 bar and H/CO = 0.5. The hydrocarbon distribution greatly deviated from the classical Anderson-Schulz-Flory (ASF) distribution, with only 2.6C% methane selectivity was obtained. XRD and TEM characterization verified that the CoC nanoprisms with special exposed facts of (101) and (020) constitutes the Fischer-Tropsch to olefins (FTO) active site. The catalytic activity increased gradually with rising the reaction temperature, while the product distribution almost kept unchanged under various reaction condition in SBR. Compared to the reaction in FBR, the CoC-based catalyst exhibited relative better catalytic performance during FTO process in SBR. Specifically, a higher CO conversion, a lower methane selectivity and a higher total selectivities to olefins and oxygenates were achieved in SBR. In addition, the catalyst can be reduced in slurry bed reactor at mild temperature (300 °C) and no obvious deactivation was found within nearly 100 h time-on-stream, which suggested a promising route for the direct production of olefins syngas in industrial application.
在浆态床反应器(SBR)中研究了基于CoC的催化剂上合成气转化直接制烯烃的过程。发现在250℃、5巴和H/CO = 0.5条件下,CO转化率为29.5%时,烯烃和含氧化合物的总选择性达到88.8C%。烃类分布与经典的安德森-舒尔茨-弗洛里(ASF)分布有很大偏差,甲烷选择性仅为2.6C%。XRD和TEM表征证实,具有特殊暴露面(101)和(020)的CoC纳米棱柱构成了费托制烯烃(FTO)活性位点。催化活性随反应温度升高而逐渐增加,而在浆态床反应器的各种反应条件下产物分布几乎保持不变。与固定床反应器中的反应相比,基于CoC的催化剂在浆态床反应器的FTO过程中表现出相对较好的催化性能。具体而言,在浆态床反应器中实现了更高的CO转化率、更低的甲烷选择性以及更高的烯烃和含氧化合物总选择性。此外,该催化剂可在浆态床反应器中于温和温度(300℃)下还原,在近100小时的运行时间内未发现明显失活,这表明在工业应用中直接由合成气制烯烃是一条有前景的路线。