Preparation and characterization of carbonaceous adsorbent from Cedar (Cryptomeria japonica D. Don) Bark

柳杉（Cryptomeria japonica D.）树皮在林业中是一种很麻烦的废物，因为如果把它留在地上，它需要很长时间才能腐烂。另一方面，活性炭虽然已经被广泛使用，但仍然是积极研究的对象，因为它们根据起始材料和制备条件显示出各种各样的性能。以日本杉皮为原料，研究了其制备活性炭的适宜条件。（1）首先研究了雪松皮在惰性气氛下的炭化行为。通过光学显微镜、表面积和孔隙度测量以及其他仪器分析来监测该过程，并找出了雪松树皮的纤维结构基本上保留的条件。（2）使用这样获得的碳质材料作为起始材料，研究在二氧化碳气氛中活化的条件，并且获得具有与商业活性炭相当的特性的活性炭。（3）对当地产生的另一种生物质废弃物稻草、谷壳等进行了炭化和活化研究，发现雪松皮最适合作为活性炭的原料。（4）以甲烷为探针，采用脉冲色谱法测定了氦气载体中的传质速率。由雪松皮制备的样品显示出比常规活性炭稍高的速率。

Cedar (Cryptomeria japonica D. Don) bark is a troublesome waste matter in the forestry because it takes long time to rot if left on the ground. On the other hand, activated carbons, although they have been widely used already, are still object of active research because they show large variety of performance depending on starting materials and preparation conditions. This work aimed at clarifying the suitable conditions for preparation of activated carbon from Japanese cedar bark.(1)Firstly, the carbonization behavior of cedar bark in inert atmosphere was investigated. The process was monitored by optical microscope, surface area and porosity measurement, and other instrumental analysis, and the condition in which the fibrous structure of the cedar bark was largely retained was found out.(2)Using the carbonaceous material thus obtained as a starting material, the condition of the activation in the carbon dioxide atmosphere was investigated, and an activated carbon having characteristics comparable to commercial ones was obtained.(3)The carbonization and the activation of another biomass waste produced in the local area, i.e. rice straw, chaff, and others, were also studied, and it was found that cedar bark is most suitable for raw material of activated carbon among the materials studied.(4)The mass transfer velocity was evaluated by a pulse chromatography adapting methane as a probe in helium carrier. The sample prepared from cedar bark showed somewhat higher rate than conventional activated carbon.