典型城市生活垃圾一次性竹筷子水热炭结构与气化反应特性关联机制研究

Correlation mechanism between structure and gasification characteristics of typical municipal solid waste(MSW)disposable bamboo chopsticks hydrochar

本研究以MSW的典型成分一次性竹筷子(DBC)为原料,研究水热炭化(HTC)条件对DBC水热炭结构性质与气化反应特性的影响规律。结果表明,HTC提高了DBC的能量品质,水热处理后DBC-230-60的高位热值(HHV)是DBC的1.62倍,H/C和O/C从DBC的1.57和0.76下降到DBC-230-60的1.00和0.33。表征发现,水热炭和水热炭半焦的芳构化程度比DBC原样更高,水热炭的比表面积低于DBC原样,但水热炭半焦的比表面积却高于DBC原样半焦。相比于水热时间,水热温度对水热炭结构和气化反应性的影响更加显著。更高的水热温度增大了水热炭的芳构化程度,降低了水热炭的气化反应性。水热炭的气化反应性比DBC原样更差,主要是因为水热炭半焦芳构化程度增大对气化反应性的消极作用大于孔隙结构丰富的促进作用。

Due to the complex composition,large fluctuation of material characteristics and low energy density of MSW,the gasification characteristics of its hydrochars are not well understood.Therefore,it is of great significance to study the gasification characteristics of single component hydrochars.In this paper,a typical component of MSW,disposable bamboo chopsticks(DBC),was used as raw material to study the effect of hydrothermal carbonization(HTC)conditions on the structural properties and gasification reaction characteristics of DBC hydrochars.The results showed that HTC improved the energy quality of DBC,the HHV of DBC-230-60 sample was 1.62 times of that of DBC,and H/C and O/C decreased from 1.57 and 0.76 of original sample to 1.00 and 0.33 of DBC-230-60.The results of characterization also demonstrate that the aromatization degree of hydrochar and hydrochar semicoke is higher than that of the DBC original one.The specific surface area of hydrochar is lower than that of DBC original sample,but hydrochar semicoke is higher than that of DBC original sample semicoke.Compared with hydrothermal time,hydrothermal temperature has the more significant effect on the structure and gasification reactivity of hydrochar.Higher hydrothermal temperature increases the aromatization degree of hydrochar and decreases the gasification reactivity of hydrochar.The gasification reactivity of hydrochar is worse than that of DBC original sample,which is mainly because the increase of the degree of semicoke arbulization of hydrochar has a greater negative effect on the gasification reactivity than the abundance of pore structure.