Abstract: This paper takes herbal dregs as raw material and supercritical water gasification as the main method to investigate the effects of temperature, time, temperature increase rate and water content on the hydrogen production characteristics of supercritical water gasification of herbal dregs. Furthermore, it investigates the catalytic effects of four various kinds of catalysts and four different Lewis acid catalysts on the supercritical water gasification of herbal dregs for the production of hydrogen, and explores the catalytic mechanism of $ AlCl_{3} $ catalyst. The experimental results showed that the change of temperature among the reaction parameters had the greatest influence on the hydrogen production from supercritical water gasification of herbal dregs, and among the four various catalysts, Lewis acid catalysts showed the best catalytic hydrogen production characteristics, and among the four Lewis acid catalysts, $ AlCl_{3} $ had the best catalytic effect on the hydrogen production. The reason why $ AlCl_{3} $ could increase the gas yield and hydrogen production when it was used as an additive was that it not only promoted the C-C bond breaking to accelerate the decomposition of macromolecules into small molecules, but also effectively promoted the free radical reaction, so that small molecules were further gasified into hydrogen and other gas-phase products. In addition, $ AlCl_{3} $ demonstrated better performance in catalytic hydrogen production across four different types of herbal dregs. The results of the study can provide certain theoretical and experimental basis for the supercritical water gasification. tion of herbal dregs to produce hydrogen-rich combustible gas.
Keywords: supercritical water gasification; herbal dregs; hydrogen production; Lewis acid catalyst; $ AlCl_{3} $ catalyst
合肥工业大学学报自科版