KMS Chongqing Institute of Green and Intelligent Technology, CAS
Metal Hydroxide-Catalyzed Heavy Oil Upgrading in Supercritical Water: Deuterium Tracing Study | |
Chen, Zhong1,2![]() ![]() ![]() ![]() | |
2024-03-05 | |
摘要 | Conversion of heavy oil is urgent as most of the explored fossil oil reserves and renewable raw biodiesel can be categorized as heavy oil. Supercritical water upgrading (SCWU) is a green and promising technology for heavy oil conversion, but the hydrogen-donating capacity of pure water is inadequate. This study adopts transition-metal hydroxide (M-OH) to enhance the in situ hydrogen-donating capacity of water for the first time. Both M-OH and the corresponding metal oxide nanoparticle (MOn) of one post-transition metal (Al) and five transition metals (Cr, Cu, Fe, Ni, Zn) are tested. The SCWU conditions are selected as 425 degrees C, 60 min, water-to-oil ratio of 4:1, catalyst-to-oil ratio of 1:10, and water density of 308 kg m(-3). Deuterium oxide (D2O) instead of H2O is used as the reaction medium for a deuterium tracing study. Results indicate that the different metal-based MOn nanoparticles display various effects on heavy hydrocarbon cracking, gasification, coke suppression, and D addition reactions. The overall performance is found to be on the order of NiO > Cr2O3 > Fe2O3 > CuO > Al2O3 > ZnO. Compared to MOn, M-OH can generally improve the oil yield and H/C ratio and reduce the coke yield simultaneously. The mechanism analysis suggests that the M-OH decomposition behavior under hydrothermal conditions is the primary cause by which MOn and lattice H2O are generated in the oil-rich phase. The lattice H2O can not only take part in SCWU reactions but also suppress coke formation. In conclusion, M-OH is a promising catalyst as it combines the good dispersibility and catalytic activity of MOn nanoparticles and the low cost of water-soluble inorganic metal salts (M-IAc) but does not result in any corrosive species, such as inorganic acid from M-IAc. |
DOI | 10.1021/acs.energyfuels.4c00100 |
发表期刊 | ENERGY & FUELS
![]() |
ISSN | 0887-0624 |
卷号 | 38期号:7页码:5738-5750 |
通讯作者 | Chen, Zhong(chenzhong@cigit.ac.cn) |
收录类别 | SCI |
WOS记录号 | WOS:001180388800001 |
语种 | 英语 |