论文部分内容阅读
运输燃料中的含硫化合物依然是空气污染的主要源头.随着人们环保意识日益增强,世界各国对燃料油标准特别是硫含量提出了越来越严格的要求.为了应对燃料油的无硫化趋势,探索新型脱硫技术去除油品中的含硫化合物成为研究热点.吸附脱硫技术(ADS)能够选择性地脱除汽油中的含硫化合物,而不影响其中的烯烃含量,从而避免了加氢精制过程中烯烃饱和导致的辛烷值降低问题,成为目前成熟的清洁油品生产技术本文采用微波辅助燃烧技术,将一定化学计量比的金属硝酸盐和尿素混合物快速燃烧反应,成功合成一系列铁氧体吸附剂(MgFe_2O_4,NiFe_2O_4,CuZnFe_2O_4,ZnFe_2O_4,CoFe_2O_4).以含有噻吩的正庚烷(总含硫量3000 mg/L)为汽油模型,在固定床反应器中500 oC反应条件下探索了所合成铁氧体吸附剂的吸附脱硫性能.结果表明,铁氧体吸附脱硫活性大小为:MgFe_2O_4>NiFe_2O_4>CuZnFe_2O_4>ZnFe_2O_4>CoFe_2O_4.其中MgFe_2O_4较其他铁氧体具有更高的吸附脱硫性能.这是由于Mg-Fe合金化程度低,而且掺杂的Mg降低了Fe与S之间的相互作用,从而显著提高了吸附脱硫性能.此外,Mg作为一种典型的碱金属可在一定程度上显著促进噻吩分解.X射线衍射和穆斯堡尔谱作为敏感的结构和组成检测手段,广泛用于解析铁氧体吸附剂在吸附脱硫过程中的结构和相态变化.通过穆斯堡尔谱成功解析了铁氧体中Fe的存在形式及其化合态.对新鲜铁氧体吸附剂、吸附脱硫后的吸附剂以及氧化再生的吸附剂进行监测对比,发现在吸附过程中铁氧体被部分硫化成Fe1-xS和双金属硫化物.在空气中经高温(500 oC)处理可成功实现铁氧体吸附剂再生.本文通过对铁氧体吸附剂的结构解析和性能测试,为新型吸附脱硫剂开发提供了理论依据.
Sulfur compounds in transport fuels are still the main source of air pollution.With the growing awareness of environmental protection, countries all over the world put forward more and more stringent requirements on fuel oil standards, especially sulfur content.In order to cope with the trend of sulfur free fuel oil , To explore the new desulfurization technology to remove sulfur compounds in oil products has become a research hot spot.Adsorptive desulfurization technology (ADS) can selectively remove the sulfur compounds in gasoline without affecting the olefin content, thus avoiding the hydrofinishing In the process of olefins saturation caused by the octane decrease, become a mature technology for the production of clean oil microwave assisted combustion technology in this paper, a certain stoichiometric metal nitrate and urea mixture rapid combustion reaction, the successful synthesis of a series of ferrite In this paper, the benzotriazole (total sulfur content of 3000 mg / L) as gasoline model was investigated in a fixed bed reactor at 500 oC reaction conditions Adsorptive desulfurization performance of synthetic ferrite adsorbents was studied.The results showed that the ferrite adsorptive desulfurization activity was as follows: MgFe 2 O 4> NiFe 2 O 4> CuZnFe 2 O 4> Zn Fe_2O_4> CoFe_2O_4. Among them, MgFe_2O_4 has higher adsorption desulfurization performance than other ferrites because of the low degree of Mg-Fe alloying, and the doped Mg decreases the interaction between Fe and S, thereby significantly improving Adsorbed desulfurization performance.In addition, Mg as a typical alkali metal can significantly promote thiophene decomposition to some extent.X-ray diffraction and Mossbauer spectroscopy as a sensitive detection of structure and composition, widely used in the analysis of ferrite adsorption Agent in the adsorption desulfurization process of the structure and phase change.Analysis of the existence of Fe in ferrite and its compound state by Mossbauer spectroscopy.For fresh ferrite adsorbent, adsorbent after desulfurization and The results showed that the ferrite was partially sulfided to Fe1-xS and bimetallic sulfide during the adsorption process, and the regeneration of ferrite adsorbent could be successfully achieved at high temperature (500 oC) in air. Through the structure analysis and performance test of ferrite adsorbent, it provides a theoretical basis for the development of new adsorbent desulfurizer.