Duan Zhiya, Fiquet Olivier, Ablitzer Carine, Cassayre Laurent, Vergnes Hugues, Floquet Pascal, Joulia Xavier
Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France; CEA, DEC, Cadarache, 13108, Saint-Paul-lez-Durance, France.
CEA, DEC, Cadarache, 13108, Saint-Paul-lez-Durance, France.
J Hazard Mater. 2021 Jan 5;401:123367. doi: 10.1016/j.jhazmat.2020.123367. Epub 2020 Jul 2.
The work deals with the removal by slow pyrolysis of epoxy resin from samples of spent nuclear fuel embedded in this polymer. Beyond the nuclear field, epoxy resin removal by pyrolysis is a typical issue for the recovery of metals in electronic waste. The main objective is to find the optimal conditions to remove hydrogen in the residual solid waste, in order to avoid hydrogen production by radiolysis during storage and so to prevent any risk of overpressure and explosion. The condensable pyrolysis products (tar-water mixture) and the char were characterised and quantified by elemental analyses, while the permanent gases were quantified by gas chromatography. A data reconciliation method was applied to adjust the values of raw measurements in order to complete the mass balances for both C, H, O and N elements and pyrolysis products. After studying the impact of temperature on the pyrolysis balance, experiments on a pilot furnace were conducted at 450 °C, in the frame of a parametric study of the heating rate, argon gas flow rate, resin mass and plateau time. At fixed temperature, we show that the plateau time is the only significant parameter for minimizing the residual hydrogen content in the char.
这项工作涉及通过缓慢热解从嵌入这种聚合物的乏核燃料样品中去除环氧树脂。在核领域之外，通过热解去除环氧树脂是电子废物中金属回收的一个典型问题。主要目标是找到去除残留固体废物中氢的最佳条件，以避免在储存期间通过辐射分解产生氢气，从而防止任何超压和爆炸风险。通过元素分析对可冷凝热解产物（焦油 - 水混合物）和焦炭进行了表征和定量，而永久性气体则通过气相色谱进行了定量。应用了一种数据协调方法来调整原始测量值，以完成碳、氢、氧和氮元素以及热解产物的质量平衡。在研究温度对热解平衡的影响之后，在中试炉中于450°C进行了实验，这是加热速率、氩气流速、树脂质量和平稳时间参数研究的一部分。在固定温度下，我们表明平稳时间是使焦炭中残留氢含量最小化的唯一重要参数。
