通过缓慢高温裂解方式生产不同温度的小麦和玉米生物质炭,并对其性质进行分析。结果显示,生物质炭性质受裂解温度和生物质种类的影响而表现出差异。当裂解温度从300℃升高到500℃时,小麦生物质炭产率从44.3%降低到38.4%,其生物质炭碳含量从617.9g/kg升高到674.0g/kg;玉米生物质炭产率从42.8%(300℃)降低到29.7%(500℃),其生物质炭碳含量从574.8g/kg(300℃)升高到651.1g/kg(500℃)。生物质炭pH、灰分含量、全磷含量等也随制炭温度升高而升高,灰分含量从186.1g/kg(300℃)升高到268.2g/kg(500℃),小麦生物质炭pH从7.59(300℃)上升到10.51(500℃),全磷含量从0.70g/kg(300℃)升高到1.10g/kg(500℃);玉米生物质炭pH从9.35(300℃)升高到10.12(500℃),全磷含量从2.34g/kg(300℃)升高到4.37g/kg(500℃)。说明制炭温度和生物质种类对生物质炭理化性质具有决定性作用。
The experiments investigated the properties of wheat and corn biochars pyrolyzed at different temperatures. Results showed that pyrolysis temperatures and original materials significantly influenced the properties of biochars. When pyrolysis temperature rose from 300 ℃ to 500 ℃, the yeild of wheat and corn biochars (biochar produced by wheat straw and corn straw) decreased from 44.3% to 38.4% and from 42.8% to 29.7%, respectively; the total carbon content of wheat and corn biochars increased from 617.9 g/kg to 674.0 g/kg and from 574.8 g/kg to 651.1 g/kg respectively. For wheat biochar, pH and total P content increased from 7.59 (300℃) to 10.51 (500℃) and from 0.70 g/kg (300℃) to 1.10g/kg (500℃), respectively; for corn biochar, pH and total P content increased from 9.35(300℃) to 10.12(500℃) and from 2.34g/kg (300℃) to 4.37g/kg (500℃), respectively. It indicated that the properties of biochar are depended on the pyrolysis temperature and original materials.