氯化铜协同低共熔溶剂(三氯化铁/乙二醇)高效氧化吸收H2S实验研究

Experimental research of the efficient oxidation and absorption of H2S by CuCl2 in cooperation with deep eutectic solvent(FeCl3/EG)

关键词:  低共熔溶剂  脱硫  硫化氢  硫磺  氧化还原法

Key words:  deep eutectic solvent  desulfurization  hydrogen sulfide  sulfur  redox process

摘要:

目的 低共熔溶剂(DES)在气体吸收领域已有一定的研究基础,鉴于其原料价廉易得、制备方法简单、绿色环保,是一种可以替代离子液体的的工业溶剂,具有广阔的应用前景,可用于解决中小规模常规含硫天然气中H₂S脱除的工业问题。方法 采用六水合三氯化铁(FeCl₃·6H₂O)、乙二醇(EG)制备了FeCl₃/EG低共熔溶剂,并加入无水氯化铜(CuCl₂)促进H₂S的吸收,最终合成DES脱硫剂FeCl₃/EG-CuCl₂。重点考查了脱硫剂原料配比、反应温度、CuCl₂浓度等因素对脱硫性能的影响,并对再生条件进行了探索。结果 原料物质的量之比为1∶1的FeCl₃/EG低共熔溶剂具有更好的脱硫效果,适当提高反应温度和CuCl₂浓度更有利于促进H₂S的吸收。脱硫剂可通入氧气进行再生,经过多次脱硫-再生重复使用,脱硫性能变化不大。脱硫产物经过XRD表征结果为斜方硫。结论 该DES脱硫剂可以高效吸收H₂S并将其转化为硫单质,实现硫元素的循环利用,可为天然气脱除H₂S气体工艺提供参考。 

Abstract:

Objective Deep eutectic solvent (DES) has a certain research foundation in the field of gas absorption. In view of its cheap and easy-to-obtain raw materials, simple preparation method, and green environmental protection, it is an industrial solvent which can replace ionic liquids. The solvent has broad application prospects which can be used to solve the industrial problem of H₂S removal in small and medium-scale conventional sour natural gas. Methods FeCl₃/EG deep eutectic solvent was prepared by ferric chloride hexahydrate and ethylene glycol(EG), and anhydrous copper chloride(CuCl₂) was added in it to promote H₂S absorption, and finally FeCl₃/EG-CuCl₂ was synthesized as a DES desulfurizer. The influence of factors such as the ratio of desulfurizer raw materials, reaction temperature and CuCl₂ concentration on the desulfurization performance was focused on, and the regeneration conditions were explored. Results The FeCl₃/EG deep eutectic solvent with a raw material molar ratio of 1∶1 had a better desulfurization effect. Appropriately increasing the reaction temperature and CuCl₂ concentration was more conductive to promoting H₂S absorption. The desulfurizer could be regenerated by introducing oxygen, and the desulfurization performance would not change much after repeated desulfurization-regeneration. The desulfurization product was characterized by XRD as rhombic sulfur(α-sulfur). Conclusion sThe DES desulfurizer can efficiently absorb H₂S and convert it into elemental sulfur, realize the recycling of sulfur and provide a reference for the process of removing H₂S from natural gas.