热解温度和生物炭粒径对苹果树枝生物炭吸湿性的影响  

Effect of Pyrolysis Temperature and Particle Size on the Hygroscopicity of Apple Twig Biochar

作　　者：刘辉[1] 赵保卫[1] 张鑫 李刘军 赵越 LIU Hui;ZHAO Bao-wei;ZHANG Xin;LI Liu-jun;ZHAO Yue(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学环境与市政工程学院,兰州730070

出　　处：《兰州交通大学学报》2023年第2期108-114,共7页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(51766008,21467013,21167007)。

摘　　要：在300,500和700℃的热解温度下制得苹果树枝生物炭,通过逐级筛分获得<0.15 mm、0.15~0.25 mm和0.25~0.43 mm的小、中和大3种粒径,研究了在不同环境温度(20,30,40℃)条件下热解温度和粒径对苹果树枝生物炭吸湿性能的影响。结果表明,热解温度的升高能够显著(p<0.05)提高生物炭的平衡含水率(EMC),尤其是中等粒径(PGC)生物炭。环境温度对生物炭的EMC也有一定的影响,低环境温度有利于提升生物炭的吸湿性。动力学研究表明,Weibull模型比Peleg、扩散模型、准一级和准二级模型更能预测生物炭的吸湿过程(R2>0.9960,RSS≤0.03)。模拟获得的动力学参数α和β的数值大小表明,热解温度和粒径对苹果树枝生物炭的吸湿速率的影响较小,但环境温度的影响较为显著(p<0.05)。因此,在利用生物炭进行实际土壤水分改善的过程中,应合理的选择生物炭的热解温度和粒径,此外还要考虑环境温度影响。In this paper,apple twig biochar was produced at pyrolysis temperatures of 300,500,and 700℃.Three particle sizes of<0.15 mm(small),0.15~0.25 mm(medium),and 0.25~0.43 mm(large)were obtained by stepwise sieving.The effects of pyrolysis temperature and partidle size on the moisture absorption properties of apple twig biochar were investigated at different ambient temperatures(20,30,and 40℃).The results showed that an increase in pyrolysis temperature significantly(p<0.05)increased the equilibrium moisture content(EMC)of the biochar,especially for medium particle size biochar.Ambient temperature also affects the EMC of biochar,with low ambient temperatures being beneficial in enhancing the moisture absorption of biochar.Kinetic studies showed that the Weibull model predicts the moisture absorption process of biochar better than the Peleg,diffusion,pseudo-first order and pseudo second order models(R^(2)>0.9960,RSS≤0.03).The values of the kinetic parameters a andβobtained from the simulations indicate that the effects of pyrolysis temperature and particle size on the moisture uptake rate of apple twig biochar are small,but the effect of ambient temperature is more significant(p<0.05).Therefore,in the process of using biochar for actual soil moisture improvement,the pyrolysis temperature and particle size of the biochar should be reasonably selected,and the influence of ambient temperature should be considered.

关 键 词：苹果树枝 生物炭 热解温度 粒径 平衡含水率(EMC) Weibull模型 

分 类 号：X71[环境科学与工程—环境工程]