Gasification And Hydrogenation Research Of Phenol In Supercritical Water With Catalysts

With the development of society, people’s demand for energy is also increasing. Preparation of biofuel or biogas (e.g. hydrogen, methane and so on) with biomass is considered as one of the most promising method. This study is on using phenol as a model compound for the complex composition of the char and bio crude to analysis the reaction products and the ring opening reaction progress so that the situation of gasification and hydrogenation of biomass could be obtained, which is based on the supercritical water technology using in gasification and liquefaction of biomass.In the research of the gasification process, Ru/CeO2 was prepared by the impregnation method. The catalyst has pore size distribution that a wide distribution from 2 nm to 30 nm. Supercritical water gasification of phenol indicates that the carbon efficiency have been improved to about 90% at the conditions that 0.5 g Ru/CeO2/g phenol was used at 550 ℃ with a water density of 0.0979 g/cm3 and a 5 wt% loading of phenol. The gaseous yields (gases vs phenol) have increased from 60% to 150% at 500 ℃ and over 100% after 5 min, indicating that nearly 50% gaseous products might be from water. The GC-MS results show that the catalytic process with Ru/CeO2 has improved hydrogenation reactions, suppressing dimers such as dibenzofuran and polycyclic aromatic hydrocarbons (PAHs) insignificantly. A kinetic model has also been developed, giving activation energy 84.24 ± 22 kJ/mol and frequency factor (In A) 12.5 ± 2.9 for gasification process,60 ± 17 kJ/mol and 7.53 ± 2.7 for char formation respectively. As Ru/CeO2 show stability in supercritical water at temperatures below 550 ℃, indicating that Ru/CeO2 supercritical water gasification system is a potential way to treat phenols for energy reuse.In the study on hydrogenation process, A HS-GC method with water removal by hydrate formation for the determination of CL, CE, and phenol in samples from the phenol hydrogenation in SWRS has been developed firstly. The method showed good precision (RSD< 5.3 %), with recoveries from spiked samples of 93-104 %. Moreover, it is simple and accurate, and thus suitable for the analysis of CL, CE and phenol in samples from phenol conversion in SWRS. And then the study on hydrogenation of Phenol in sub - and supercritical conditions with two kinds of Lewis acid has been taken on. When join Lewis acid enough, there is a certain improving effect on cyclohexanone selectivity, while a negative effect on the conversion rate of phenol and benzene yield. Compare to the Lewis acid, Higher temperature has a bigger effect on the hydrogenation result, which favors the benzene formation while lower temperature favors cyclohexanone. However, raising temperature has nearly no influence on the hydrogenation efficiency of phenol.