摘要
催化裂解能够有效减小放射性废树脂的体积,但温度过高有可能导致裂解过程中核素挥发。为降低裂解温度,本文采用原位Fe_(2)O_(3)对放射性废阳离子树脂进行催化裂解。结果表明,通过离子交换法将Fe^(3+)负载至阳离子树脂上,在裂解过程中原位生成Fe_(2)O_(3),能够使树脂的裂解温度降至650℃左右,比直接热裂解低130~150℃,且残渣率降低至15%(650℃)。对裂解残渣进行FT-IR、XRD、XPS和元素分析,结果发现Fe^(3+)原位生成的Fe_(2)O_(3)有效促进了磺酸基(-SO_(3)H)的转化及硫键(-S-)的断裂,树脂中83.1%的硫元素转化为SO_(2),16.9%的硫元素以硫酸盐的形式进入残渣中。上述实验结果表明,原位生成的Fe_(2)O_(3)能显著降低阳离子树脂的裂解温度和残渣率,能够实现放射性废树脂的有效减容。
Catalytic pyrolysis can effectively reduce the volume of radioactive waste resin;however,the high pyrolysis temperature may result in nuclide volatilization.To mitigate this issue,Fe_(2)O_(3)formed in situ was employed as a catalyst for the pyrolysis of radioactive waste cation resin.Experimental findings revealed that Fe^(3+)doped into the resin through ion exchange transformed into Fe_(2)O_(3)during the pyrolysis process,thereby reducing the resin's pyrolysis temperature to approximately 650℃,which is 130~150℃lower than direct pyrolysis without catalysts,and decreasing the residual rate to 15%(650℃).The solid residue of waste resin after pyrolysis was subjected to FT-IR,XRD,XPS,and elemental analyses.These analyses demonstrated that Fe_(2)O_(3)facilitated sulfonic acid group(-SO_(3)H)conversion and sulfur bond(-S-)breakdown.Specifically,it was determined that 83.1%of sulfur in the resin converted to SO_(2)while 16.9%entered into the residue as sulfate.Overall,these results indicate that in situ Fe_(2)O_(3)significantly reduces both pyrolysis temperature and residue rate while achieving effective volume reduction of radioactive waste resin.
作者
李林倚
肖霄
廖学品
石碧
LI Lin-yi;XIAO Xiao;LIAO Xue-pin;SHI Bi(College of Biomass Science and Engineering,Sichuan University,Chengdu 610065,China;Key Laboratory of Leather Chemistry and Engineering of Ministry of Education,Chengdu 610065,China)
出处
《化学研究与应用》
CAS
北大核心
2024年第8期1791-1799,共9页
Chemical Research and Application
基金
国家自然科学基金区域创新发展联合基金项目(U21A20304)资助。
