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

雪松树皮是林业中的一种令人头疼的废弃物，如果留在地上，腐烂的时间很长。另一方面，虽然活性碳已经得到了广泛的应用，但由于其因原料和制备条件的不同而表现出不同的性能，因此仍然是活跃研究的对象。本工作旨在明确以日本雪松树皮为原料制备活性碳的适宜条件。(1)首先，研究了雪松树皮在惰性气氛中的炭化行为。通过光学显微镜、比表面积和孔隙率测量等仪器分析手段对活化过程进行了监测，找出了雪松树皮纤维结构基本保持的条件。(2)以所制得的碳质材料为原料，考察了在二氧化碳气氛中活化的条件，得到了与商品炭相当的活性碳。(3)对当地产生的另一种生物质废弃物稻草、谷壳等进行了炭化活化研究。在所研究的材料中，雪松树皮最适合作为活性碳的原料。(4)以甲烷为探针，用脉冲层析法测定了在氦气中的传质速度。从雪松树皮制备的样品显示出比常规活性碳稍高的反应速率。

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.