Abstract: Molded biochar was prepared at pyrolysis final temperatures of 400℃, 500℃, 600℃, 700℃, 800℃ and oxygen content of 0, 2%, 4%, 6% respectively. Using the scanning electron microscopy (SEM) and the specific surface area analyzer (SSA), the pore structure characteristics of the obtained molded biochar were analyzed. The effects of pyrolysis atmosphere with different final temperatures and different oxygen contents on the pore structure of molded biochar were studied. The results showed that, under the condition of inert atmosphere, the specific surface area increased firstly and then gradually decreased with temperature ranging from 400℃ to 800℃. The macro-porous were more easily observed from the SEM in the final temperature at 800℃. As the oxygen concentration was large, which promoted the pyrolysis. The specific surface area and the pore volume increased when the temperature remained constant and the oxygen volume fraction increased from 0 to 6%, but the rate of the increase decreased when at 600~800℃. It showed that with the same oxygen content pyrolysis atmosphere, with the increase of the final temperature, the specific surface area first increased and then decreased. At the same final temperature, the specific surface area increased with the increase of oxygen content in the pyrolysis atmosphere, while the specific surface area increase slowed down at higher final temperature and higher oxygen content in pyrolysis atmosphere. And the increase of specific surface area helped enhance the sorption capacity of the molded biochar.

Key words: molded biochar, temperature, oxygen content, constant temperature pyrolysis, pore structure

摘要： 分别在400℃、500℃、600℃、700℃、800℃的热解终温和0、2%、4%、6%含氧量的热解气氛条件下制备成型生物质炭，通过扫描电镜、比表面积仪等测试手段对制得的成型生物质炭进行孔结构特性分析，研究了热解制备成型生物质炭时不同终温和不同含氧量的热解气氛对成型生物质炭孔隙结构的影响。结果表明，具有相同含氧量的热解气氛条件下，随着终温从400℃升高到800℃，比表面积先升高然后逐渐降低。从扫描电镜图中也可以发现终温在800℃时，大孔更易被观察到。在终温不变条件下，热解气氛的氧气体积分数从0上升到6%时，由于氧浓度增大，对热解产生了促进作用，加速热解反应，比表面积总体上升，微孔、中孔孔容积总体增加，但是在600～800℃时增加趋势放缓。说明在相同含氧量的热解气氛下，随终温升高，比表面积先增加后降低。相同终温下，随着热解气氛中含氧量的增加比表面积增加，而在较高终温和较高含氧量的热解气氛条件下，比表面积增加减慢，而比表面积的增加有利于加强成型生物质炭的吸附能力。

关键词: 成型生物质炭, 温度, 含氧量, 常速热解, 孔结构