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Phenol, a substance difficult to be gasified, is often an intermediate product from biomass gasification in supercritical water. In this study, 1 wt % phenol is gasified in supercritical water with different oxidation coefficients (0 ≤ n≤ 0.8) at 430−550 °C, 25 MPa in a continuous tubular-flow reaction plant with or without 0.1 wt % Na2CO3. The results show that TOC (total organic carbon) removal rate and COD (chemical oxygen demand) removal rate of reactor effluent will rise with the increase of oxidation coefficient and reaction temperature. When nrises from 0.3 to 0.8 at 500 °C, hydrogen yield and hydrogen molar fraction will first increase and then decrease. They reach their respective maximum values of 0.245 mol/mol and 46.2% at n= 0.6 with the residence time of 2.96 min. There is an appropriate oxidation coefficient for obtaining the highest hydrogen yield for phenol supercritical water partial oxidative gasification (SWPO). Na2CO3can serve as a catalyst or an additive for phenol SWPO. When 0.1 wt % Na2CO3is added, hydrogen yield is near 0.477 mol/mol at n= 0.6, 500 °C with the residence time of 2.96 min. Furthermore, the potential conversion pathways for phenol SWPO with Na2CO3catalyst are also proposed. [ABSTRACT FROM AUTHOR]

Copper(II) oxide ultrafine particles are of great interest as a new material for multiple applications. This paper expounds the synthesis and characterization of copper(II) oxide submicrometer particles formed by a facile and simple supercritical hydrothermal synthesis method. The copper(II) nitrate, copper salt, was used as a precursor aqueous solution heated by a preheated sand bath to reach supercritical conditions. The effects of process operating parameters, such as temperature, pressure, the addition of sodium hydroxide, and precursor concentrations on the morphology and the size of copper(II) oxide submicrometer particles have been investigated. The copper(II) oxide particles formed, with particle sizes of ca. 100 nm, were hexagon-flake-like and spindle-like and free of impurities. The average particle size decreased with the increase of temperature under subcritical conditions and decrease of pressure. It decreased with the increase of precursor concentration at lower concentration conditions and revealed an adverse trend at higher concentrations. Sodium hydroxide accelerates the conversion of copper ions. [ABSTRACT FROM AUTHOR]