餐厨垃圾水热炭化产物分配规律及液固产物特性研究

以实采餐厨垃圾为对象,探究了3种反应强度("温和"180℃-1h、"中等"220℃-2h和"剧烈"260℃-4h)下餐厨垃圾水热炭化三相产物分配规律及液固产物特性.结果表明,反应强度显著影响产物分配.随反应强度提升,固相产物(水热炭)产率先上升后下降;液相产物(炭化液)产率先降低后趋于稳定;而气相产物产率持续上升.但无...

The product distribution of hydrothermal carbonization of food waste and the characteristics of liquid-and solid-products

The food waste (FW) collected from a canteen was treated by hydrothermal carbonization (HTC) under three different process conditions: mild (180℃-1h), intermediate (220℃-2h) and severe (260℃-4h), to explore the effects of process severity on the distribution of HTC three-phase products and the characteristics of liquid and solid products. The results showed that the process severity significantly influenced the product distribution. With the increase of the process severity, the yield of hydrochar increased initially and then decreased, the yield of carbonization liquid decreased initially and then stabilized, while the yield of gas product kept increasing. However, despite of different process severities, the HTC products were mainly in the form of hydrochar (40.4%~52.1%), of carbonization liquid (38.3%~57.5%), with a small fraction of gas products (2.1%~13.3%). In addition, the process severity also significantly affected the characteristics of carbonization liquid and hydrochar. With the increase of the process severity, the pH level of the carbonization liquid gradually increased, while COD and sCOD gradually decreased, and the conductivity showed an initial decreasing and then increasing trend. Further qualitative analysis found that the carbonization liquid contained a variety of ketones, aldehydes and volatile fatty acids (VFAs). As the reaction intensity increased, the surface of the hydrochar became more rough and complex, and the specific surface area gradually increased. Meantime, the hydrothermal carbonization reaction contributed to the enrichment of the carbon element from the FW into the hydrochar, and the degree of enrichment increased remarkably with the increasing process severity. Due to the low ratios of H/C and O/C, the calorific values of hydrochar is 23.9MJ/kg, similar to the bituminous coal value of 28.3MJ/kg, and the high ignition temperatures from 267.5℃ to 302.3℃, the hydrochars produced from FW exhibited the potential of safe and clean fuel for energy production.