废弃菌棒的热解及其生物炭的活化

Pyrolysis of edible fungi residues and the preparation of activated carbon from biochar

用废弃的菌棒作为原料,利用高温管式炉对其进行热解及活化,探究废弃菌棒在不同热解温度下的热解性能及不同活化条件下的活化性能,并对最优条件下获得的活性炭进行表征,结果表明:热解终温的升高有利于制备富氢燃气,热解终温为900℃时气体产量最大(489 L/kg),其中H_2占55.55%,CO占31.93%,CH_4占8.52%;选择热解终温为600℃比较有利于液相的生成,此时液相产率为29.50%;选择400℃的热解终温有利于生成热值较高且产率较高的固体燃料,此时炭产率为48.23%,热值20.66 MJ/kg。此外,以热解终温600℃、升温速率20℃/min、热解反应时间1 h条件下制得的生物质炭为原料,在不同条件下进行活化,发现当碱碳比为1、活化时间为1 h、活化温度为800℃时制备的活性炭具有最佳的吸附性能,此时活性炭产率为31.20%,比表面积为1 659.812 m^2/g,亚甲基蓝脱色能力为615.32 mg/g,碘吸附值达到1 563.90 mg/g。

Pyrolysis of edible fungi residues at different temperatures and the subsequent preparation of activated carbon from the resulting biochar assisted by KOH have been studied. The performance of the activated carbon obtained using the optimum conditions was characterized by different methods. In the pyrolysis experiments it was found that increasing the temperature promoted the preparation of hydrogen-rich gas. The maximum gas yield of 489 L/kg was obtained at 900 ℃. There was about 56% H2, 32% CO, and 8.5% CH4. A temperature of 600 ℃ was more conducive to produce liquid products, and the yield was 29.5%. A final temperature of 400 ℃ resulted in an enhanced a yield of solid fuels and a high calorific value;the biochar yield was 48.2% with a calorific value of 20.7 MJ/kg. The biochar obtained at 600 ℃ was selected for the preparation of activated carbon. The optimum preparation conditions were as follows: KOH/biochar ratio of 1∶1, reaction time of 1 h and activation temperature of 800 ℃. The iodine number, the amount of methylene blue adsorption and the yield of activated carbon prepared under the optimum conditions were 1 564 mg/g, 615 mg/g and 31.2%, respectively. The specific surface area was 1 660 m2/g.