Numerical study on supercritical water partial oxidation of ethanol in a continuous reactor

Abstract

Supercritical water partial oxidation (SCWPO) is a green technology favorable for low-carbon organic waste resource conversion and utilization. At present, there is a lack of reasonable optimization methods for the SCWPO reactor. In this paper, a numerical model was established for the SCWPO reactor based on ethanol. Herein, a numerical study on SCWPO of ethanol in a continuous reactor was carried out. On the basis, the fluid flow, heat transfer, and gas products distribution in the SCWPO reactor were analyzed in detail, and the influence of different operating parameters was also discussed. The results showed the carbon gasification efficiency (CE) and gas yield increased with the wall temperature, ethanol concentration, and the equivalent ratio of oxidant (ER). The lower feed inlet height and the lower flow rate of feed inlet and preheated water could extend residence time and improve CE and gas yield. In particular, CE was 98.6% when the wall and preheated water temperature were 700 °C, and the height of the feed inlet was 500 mm. Under the current operating condition, the SCWPO reactor could achieve auto-thermal with ER = 0.25. Given the above, this numerical study would provide an effective method for SCWPO reactor optimization.