[关键词]
[摘要]
分别将棉杆、木屑两种单一的生物质原料及其混合原料成型(炭化压力60 MPa)造粒,并于固定床热解炉内对成型生物质进行炭化实验,分析炭化温度(400、500和600 ℃)及棉杆的掺混比例对成型炭理化性能的影响。研究表明:物理特性方面,随着炭化温度的升高,生物质成型炭的表观密度和抗压强度均呈先减小后增大的趋势;相同炭化温度条件下,随着棉杆掺混比例的增加,成型炭的表观密度增大,但抗压强度呈先减小后增大的趋势;化学特性方面,随着炭化温度的升高,成型炭的热值增加,但燃烧特性变差,灰分产率增加;随着棉杆掺混比例的增加,成型炭的燃烧特性改善,但热值降低,灰分产率增加;通过先成型再炭化制得的成型炭灰分和固定碳产率均优于欧盟标准EN1860-2:2005;在炭化温度为400、500和600 ℃时成型生物质中至少含有20%、40%和60%的棉杆可使其燃烧特性指标优于商用烧烤炭。
[Key word]
[Abstract]
ABSTRACT :In this paper, cotton stalk, wood sawdust and their blends were densified firstly and then carbonized at 400~600 ℃ by using a fixed bed pyrolyzing furnace. The physic-chemical characteristics of the resulted carbonized pellets were studied to assess the feasibility of carbonized pellets.The results indicate that both the bulk density and compression strength of carbonized pellet decrease firstly and then increase with increasing pyrolyzing temperature.The carbonized pellets blended with more cotton stalk have higher bulk density, but the compression strength decreases initially and then increases. In terms of chemical property,the heating value of carbonized pellets increases with poorer combustion characteristics and higher ash yield when the pyrolyzing temperature rises. The carbonized pellets with more cotton stalk have better combustion characteristics but the heating value decreases and ash yield increases. The ash and fixed carbon yield of all the carbonized pellets prepared at 400~600 ℃ could meet European Standard EN 1860-2. Compared with commercial barbecue charcoal, the carbonized pellets show better combustion reactivity when at least 20%, 40% and 60% of the cotton stalk are mixed at the carbonized temperature of 400, 500 and 600 ℃.
[中图分类号]
TQ531.6
[基金项目]
国家科技支撑计划资助项目(2012BAA04B01);上海理工大学科技发展项目(16KJFZ094)