Experimental investigation on gasification characteristic of food waste using supercritical water for combustible gas production: Exploring the way to complete gasification

摘要

The supercritical water gasification of food waste has potential to produce hydrogen-rich syngas and eliminate energy consumption for feedstock drying. In this study, a parametric research on supercritical water gasification of food waste under various conditions was conducted with a micro quartz tube batch reactor to explore the way to complete gasification of food waste. The results showed that the complete gasification was basically realized with the carbon gasification efficiency reaching 98% under the operating parameters of temperature, concentration and residence time of 850 degrees C, 5 wt% and 10 min. The oxidant equivalent ratio significantly improved the gasification efficiency, but led to a decrease in hydrogen yield and cold gas efficiency. Determined by response surface methodology, the quantitative relationship function between the three most important parameters and responses can effectively predict experimental results. The function revealed that the order of the effects of the factors on carbon gasification efficiency and gas yield is the temperature > time > concentration. A novel ionic liquid-assisted two-step supercritical water gasification method was proposed and performed in this study. The results showed that pretreatment of food waste with ionic liquid improved the carbon gasification efficiency, cold gas efficiency, methane yield and hydrogen yield potential obviously. The ionic liquid-assisted two-step supercritical water gasification method is effective to realize complete gasification of food waste.