不同粒径生物炭对苯酚及生物油的吸附性能  

Study on adsorption performance of biochar with different particle size on phenol and bio-oil

作　　者：严姗姗 楚生玺 许昊 朱浩楠 陈浩然 高雯然 张书 YAN Shanshan;CHU Shengxi;XU Hao;ZHU Haonan;CHEN Haoran;GAO Wenran;ZHANG Shu(College of Materials Science and Technology,Nanjing Forestry University,Nanjing 210037,China;College of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210023,China)

机构地区：[1]南京林业大学材料科学与工程学院,南京210037 [2]南京师范大学能源与机械工程学院,南京210023

出　　处：《林业工程学报》2023年第4期95-101,共7页Journal of Forestry Engineering

基　　金：国际科技创新合作重点项目(2018YFE0183600);江苏省自然科学基金(BK20200794);国家自然科学基金(51876093,52106249);煤燃烧国家重点实验室开放基金(FSKLCCA2304)。

摘　　要：为了研究不同粒径对生物炭吸附生物油(尤其是以芳香族化合物为代表的受热易结焦组分)的影响,推动解决生物油结焦问题,选用不同粒径的松木为生物质原料,采用CO_(2)活化法在800℃下制备不同粒径的松木炭并进行一系列表征,研究粒径对于生物炭吸附苯酚及生物油能力的影响。实验结果表明:4种不同粒径的生物炭在元素含量、表面官能团方面均表现出较小的差异;粒径大的生物炭微孔较丰富、石墨化程度略低,这可能与活化过程中热量传递及CO_(2)的扩散有关。此外,生物炭粒径越大,对苯酚和生物油的吸附效果越好,4种粒径的生物炭对生物油中糖类、酚类、酸类、酮类和醛类都具有很好的吸附作用,并且对酸类和酚类物质的选择性较强。生物炭对生物油的吸附机制主要为氢键作用、π-π相互作用、静电作用和孔隙填充作用,同时生物炭微孔较多、含氧官能团丰富、石墨化程度也相对较高,有望对生物油及易结焦的芳香族化合物实现较好的吸附。Bio-slurry is a slurry fuel prepared from the mixture of bio-oil and biochar produced by rapid pyrolysis of biomass,which can be used for combustion,pyrolysis,and gasification,and is a promising alternative to traditional fossil fuels.However,the presence of large amounts of phenolic compounds in bio-oil tends to polymerize and coke when being heated,seriously hindering the wide application of the bio-slurry.As a by-product of bio-oil preparation,biochar is a promising adsorbent and catalyst that can confine phenolic compounds in pores by adsorption,which in turn catalyzes the cracking of phenolic compounds and ultimately inhibits the coking of bio-slurry.The particle size of biochar may affect the adsorption performance of biochar and the physicochemical properties of bio-slurry.However,the limited studies about the effect of particle size on bio-oil adsorption by biochar have been carried out.In this study,biochar samples were prepared by CO_(2)activation at 800℃from pine wood with different particle sizes,and the structure of biochar was analyzed by various characterization methods.In the adsorption experiments,as a model compound of bio-oil aromatic fraction,phenol was firstly adsorbed by biochar,and the adsorption behavior of phenol by biochar samples was investigated in combination with the adsorption kinetics.Then bio-oil was adsorbed by biochar in bio-slurry,and the differences of bio-oil components adsorbed by biochar samples were analyzed by the gas chromatography-mass spectrometry(GC-MS)to investigate the effect of particle size on bio-oil adsorption by biochar in bio-slurry system,and to clarify the structure of biochar that can selectively adsorb aromatic compounds in bio-oil.The results showed that the biochar samples prepared from four different particle sizes of pine wood showed small differences in the elemental content and surface functional groups.The biochar with larger particle size had richer micropores and slightly lower graphitization,which might be related to the heat transfer and CO_(2

关 键 词：生物炭 粒径 生物油 苯酚 吸附 

分 类 号：TK6[动力工程及工程热物理—生物能]