关键词: 成型生物质炭, 温度, 含氧量, 常速热解, 孔结构

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