农业废弃物水洗前后热解特性的变化  

Changes in pyrolysis characteristics of agricultural residues before and after water washing

作　　者：胡睿 万诗琪 毛峰 王杰[1] HU Rui;WAN Shi-qi;MAO Feng;WANG Jie(Department of Chemical Engineering for Energy,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学,能源化工系,上海200237

出　　处：《燃料化学学报》2021年第9期1239-1249,共11页Journal of Fuel Chemistry and Technology

摘　　要：首先对花生秸秆、高粱秸秆和芦苇三种农业废弃物进行了水洗预处理,再利用固定床反应器进行了热解实验,借此考察水洗前后碱金属和碱土金属(AAEMs)和纤维组成的变化及其对农业废弃物热解特性的影响。研究发现,水洗可脱除52.7%−92.6%的钾和一半左右的中性溶解物(NDS)。AAEMs和NDS的脱除对热解农业废弃物热解产生综合影响,含AAEMs和NDS较多的花生秸秆影响尤为明显。AAEMs的脱除遏制脱羧基、脱羰基、脱氢及挥发分二次缩聚反应,而NDS的脱除直接影响气体和液体的产率和组成。对于所有三种农业废弃物,水洗后均有利于提高生物油和生物炭产率,但气体产率降低;水洗后生物油中含氧化合物增多,其中,糖类和呋喃类增幅最大,而烃类、含氮化合物减少。水洗后,花生秸秆的CO_(2)、CO和CH_(4)产率均明显降低,而生物油中长链脂肪酸的占比增大。Three agricultural residues(peanut straw,sorghum stalk and reed)were first pretreated by water washing,with which the pyrolysis experiments were carried out in a fixed bed reactor to investigate how the pyrolysis characteristics are changed by removing the alkali earth metals(AAEMs)and a part of fibrous components by water washing.The result shows that the water washing removes 52.7%–92.6%potassium and approximately half of neutral detergent solute(NDS)from three agricultural residues.The removal of AAEMs and NDS has a complex influence on the pyrolysis of agricultural residues,especially for peanut straw due to its higher contents of both AAEMs and NDS.However,the removal of AAEMs has an inhibitory effect on the reactions such as decarboxylation,decarbonylation,dehydrogenation and polycondensation,and the elution of NDS directly affects the yields and composition of gas and liquid products.For all three agricultural residues,overall,the water washing promotes the production of bio-oil and bio-char,but it lowers the gas yield.The bio-oils generated from the water-washed agricultural residues have higher proportions of oxygenates,especially sugars and furans,with lower proportions of hydrocarbons and nitrogenous compounds.Besides,after washing,the yields of CO2,CO and CH_(4) with peanut straw decrease significantly,while the proportion of long-chain fatty acids in bio oil increases.

关 键 词：生物质 水洗 热解 无机矿物 中性溶解物 

分 类 号：TK6[动力工程及工程热物理—生物能]