络合铁法脱硫再生机理研究进展  

Research Progress in the Regeneration Mechanism of Chelated Iron Desulfurization Solution

作　　者：罗莹[1] 祁极冰 郭芳[1] 

机构地区：[1]中北大学超重力化工过程山西省重点实验室,太原030051

出　　处：《化学通报》2016年第7期597-603,共7页Chemistry

基　　金：国家自然科学基金项目(21376229)资助

摘　　要：氨基多羧酸螯合铁催化氧化硫化氢实现了铁基催化剂的循环利用,其中催化剂亚铁离子再生是整个脱硫技术的核心。再生过程中,由于反应速率常数比值的不同,Fe2+的反应级数出现1级、2级乃至其间变化的各种结果;分子氧(O2)及其衍生物(如:超氧化物(Hn+O-·2)、过氧化氢(H_2O_2)、羟基自由基(OH·))或高价的含氧铁中间体(如(L)Fe4+=O、(L+)Fe4+=O和(L)nFe4+(OH)(OOH))均可以氧化亚铁离子;典型配体EDTA、HEDTA和NTA螯合亚铁的氧化机制是一致的。再生过程中配体有一个适宜的p H范围,配体NTA过量时,其活性依赖p H和NTA的浓度,NTA量的差别导致不同的反应途径。同时,由于氧化过程中配体消耗了过量的氧导致螯合铁发生降解,从而造成化学反应计量数的偏差。The chelated iron desulfurization has realized the catalyst recycling,in which ferrous ion regeneration is the core of the whole technology. In the regeneration process,researchers found the reaction to be first order,second order in Fe^（2 ＋）,and even found a transition in reaction order from 1 to 2,due to the different reaction rate constant ratio. The ferrous ion can be oxidized by molecular oxygen（ O2） and its derivatives（ such as superoxide（ Hn＋O-·2）,hydrogen peroxide（ H_2O_2）,hydroxyl radical（ OH·）） or high valence state of iron containing oxygen intermediates（ such as（ L） Fe^（4 ＋）= O,（ L· ＋） Fe4 ＋= O and（ L）nFe4 ＋（ OH）（ OOH））. The oxidation mechanism of ferrous NTA appeared to be similar to that of ferrous chelates of EDTA and HEDTA. In the regeneration process,there was a suitable p H range for the ligand. When ligand NTA was excessive,its activity depends on the p H and the concentration of NTA,and the differences of the NTA concentration lead to different reaction pathways. In the oxidation reactions,the chelate degradation occurred due to the excess oxygen consumption by the ligand,which leads to the deviation of the stoichiometry.

关 键 词：螯合亚铁 硫化氢 再生 羟基自由基 化学计量数 

分 类 号：O643.36[理学—物理化学]