餐厨垃圾水热炭化:理化特性、碱(土)金属迁移及气化反应性研究OA

To address the high moisture content and low energy efficiency of traditional food waste processing,a hydrothermal carbonization(HTC)coupled with a non-isothermal gasification process was employed to modify,upgrade,and efficiently utilize food waste.Under preparation condi-tions of a 180℃-240℃temperature range and a 60 min residence time,hydrochar(hydrothermal carbon)from food waste was produced.The study investigated the effects of temperature on the physicochemical properties of the hydrochar,the speciation of alkali and alkaline earth metals(AAEMs),and their gasification reactivity.The results show that as the hydrothermal temperature increases from 180 ℃ to 240 ℃,the carbon content of the food waste rises from 41.15％to 68.09％,and its calorific value increases from 15.63 MJ/kg to 28.84 MJ/kg,significantly improving the energy density.The hydrothermal carbonization process primarily involves dehydration and decarbox-ylation reactions,which markedly reduce n(H)/n(C)and n(O)/n(C),enhance the coalification degree of the hydrothermal carbon,and strengthen aromatization reactions at higher temperatures.The surface of the hydrothermal carbon forms abundant microspherical particles and cross-linked struc-tures,developing a pore architecture that provides more reaction sites for gasification.Additionally,the removal ratios of AAEMs increase with temperature,with the removal ratio of active potassium reaching as high as 89.91％,effectively mitigating slagging and ash deposition issues caused by these metals during gasification.The hydrothermal carbonization pretreatment improves the ignition tem-perature and volatilization characteristics of the hydrochar,enhancing its thermal stability in subse-quent non-isothermal gasification processes.