离子液体吸收废印刷线路板热拆解过程中挥发性有机物——基于COSMO-RS模型

Absorbing volatile organic compounds discharged during thermal dismantling of waste printed circuit boards using ionic liquids--based on COSMO-RS model

模拟废印刷线路板(WPCB)的热拆解过程,分析热拆解过程中的挥发性有机物(VOCs)组分;利用真实溶剂似导体屏蔽(COSMO-RS)模型对浓度较高的污染物进行量子力学模拟,研究离子液体(ILs)组成单元对目标污染物溶解度的影响差异,分析溶解过程中主导分子间作用力类型,确定优选吸收剂;测定不同溶剂进行溶解性,验证模型适用性.结果表明:①乙酸乙酯和环戊酮是浓度较高的VOCs组分,在240和250℃时浓度分别为43.1,153mg/m^3和105,252mg/m^3,质量百分比总和分别为76.3%和67.3%.②高表面屏蔽电荷密度分布峰、长烷基链阴阳离子和亲电基团的存在可提高乙酸乙酯和环戊酮在ILs中的溶解度.双三氟甲磺酰基亚胺盐(NTf2-)类ILs是一类优良吸收剂.静电力和范德华力对溶解过程起主导作用.③COSMO-RS模型可定性和半定量用于预测乙酸乙酯和环戊酮的溶解度.

Simulated thermal dismantling of WPCB(waste printed circuit boards)was carried out and VOCs(volatile organic compounds)discharged during this processwere analyzed.COSMO-RS(conductor-like screening model for real solvent)model was used to predict the solubility of VOCs with higher concentration by quantum chemistry simulation,study the influence of ILs(ionic liquids)’components andthe leading interaction energy during the absorbing process,and determine the suitable absorbents.The solubilityin different solvents were experimented to verify the potential utilization of COSMO-RS model.The results showed that:①ethyl acetate and cyclopentanonewere two main substances with higher concentration.The concentration was 43.1,153 mg/m^3 and 105,252 mg/m^3,and the total concentration percentage was 76.3%and 67.3%under 240 and 250℃,respectively.②Higherσ-profile peak,longer cations and anions alkyl chain length and the existence of electrophilic group could increase the solubility of these two compounds.NTf2-based ILs were chosen as excellent absorbents.Misfit and van de Waal energy played the leading roleduring the absorbing process.③COSMO-RS model couldbe used to predict the solubility of ethyl acetate and cyclopentanone qualitatively and semi-quantitatively.