含Cd油菜秆热解实验研究  

Experimental research on pyrolysis of Cd contaminated rape stalk

作　　者：蔡攀[1] 蒋绍坚[1] 彭好义[1] 朱明伟 王凯 王浩[1] 刘僖 CAI Pan;JIANG Shaojian;PENG Haoyi;ZHU Mingwei;WANG Kai;WANG Hao;LIU Xi(School of Energy Science and Engineering, Central South University, Changsha 410083, China)

机构地区：[1]中南大学能源科学与工程学院

出　　处：《中南大学学报（自然科学版）》2019年第8期2018-2025,共8页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(21577176)~~

摘　　要：以含Cd油菜秆(Cd-RS)为研究对象,通过热解实验研究重金属Cd对油菜秆(RS)热解产物的影响规律以及Cd在油菜秆热解过程中的迁移转化机制。研究结果表明:Cd-RS生物油产率随热解温度升高呈先升高后降低趋势,并在500℃达到最大值,为50.95%;适量Cd可有效提高生物油和生物炭产率,同时大幅降低生物气产率。Cd导致气体产物中的H2体积分数升高,CO2,CO和CH4体积分数降低,同时气体热值大幅降低。相比于RS,Cd-RS热解炭中的固定组分的质量分数降低,挥发分和灰分质量分数升高,C和H质量分数降低,O质量分数升高,热值大幅下降。随着热解温度从400升至600℃,Cd的保留率从84.97%快速降至4.29%,适当降低热解温度可有效防止油菜秆中Cd的挥发,油菜秆中的Cd经热解后以单质Cd,CdO和CdS形式存在于热解残炭中,其对环境的危害性大大降低。Cd contaminated rape stalk (Cd-RS) was taken as the research object, the effects of Cd on the pyrolytic products of rape stalk(RS) and the migration and transformation mechanism of Cd during pyrolysis of rape stalk were studied by pyrolysis experiments. The results show that the bio-oil yield of the Cd-RS increases firstly and then decreases with the rise of pyrolysis temperature, and it reaches the maximum value for 50.95% at 500 ℃. The presence of an appropriate amount of Cd results in the increase in the yield of bio-oil and biochar, and a significant reduction in biogas yield. The existence of Cd can increase the volume fraction of H2 and reduce the volume fraction of CO2, CO and CH4 of biogas, while the gas calorific value decreases due to Cd. Compared with the RS, the fixed content of biochar obtained from Cd-RS decreases significantly, while the volatile and ash content increases. Besides, mass fraction of C and H decreases, while the mass fraction of O increases. At the same time, the calorific value of biochar decreased significantly. With the pyrolysis temperature rises from 400 to 600 ℃, the retention rate of Cd decreases rapidly from 84.97% to 4.29%. Reducing the pyrolysis temperature can effectively prevent the volatilization of Cd in the rape stalk. Cd of the rape stalk exists in the form of Cd, CdO and CdS in the pyrolytic residue after pyrolysis, and the environmental hazards of cadmium is greatly reduced.

关 键 词：植物修复 油菜秆 重金属 热解 迁移转化 

分 类 号：TK6[动力工程及工程热物理—生物能]