生物质黑碳的制备及表征

Preparation and Characterization of Biochar

生物质黑碳的多孔结构使得它具有很强的吸附能力,其表面上的各种官能团具有活跃的化学反应活性,黑碳的多孔结构及表面吸附性能决定了它是其它环境污染物的重要载体之一,在大气环境界面化学中具有重要作用。本文以松木木屑、水稻秸秆和蜂窝煤为型燃烧源,通过采用自制的管式反应炉将不同典型燃烧源在300～500℃无氧条件下燃烧来制备黑炭样品,并对黑碳样品进行表征,获得不同典型燃烧源黑碳颗粒物的理化参数。实验结果表明:由松木屑制备得到的黑碳具有较高的碳质组分含量(> 66%)和较低的无机元素含量(<8%),且不含Pb、Cd等重金属组分;在300℃下制备得到的黑碳具有具有较丰富的羟基、羧基、羰基等活性基团和较高的OC/EC比值,且平均粒径小,其理化特征更接近大气气溶胶黑碳的性质,可用于模拟黑碳大气环境化学界面过程。

The porous structure of biochar makes it highly adsorbent,and various functional groups on its surface have active chemical reactivity.The porous structure and surface adsorption of black carbon make it one of the important carriers of other environmental pollutants and play an important role in interface chemistry of atmospheric environment.This paper takes pine sawdust,rice straw and honeycomb coal as combustion sources,using self-made tubular reactors of different typical combustion source anaerobic combustion in 300℃~500℃under the condition of the preparation of samples of biochar.With characterized samples,physical and chemical parameters of biochar particles from different typical combustion sources were obtained.The results indicate that the sawdust-prepared biochar posses higher carbonaceous content(>66%)and lower the content of inorganic elements(<8%),without Pb,Cd and other heavy metal components;The biochar synthesized at 300℃got higher abundance of hydroxyl,carboxyl,carbonyl and other active groups with higher OC/EC ratio.Particle sizes is short in average.Its physical and chemical characteristics are similar to the natural atmospheric aerosol biochar,which can be used to simulate the process of environmental chemistry of biochar.