资双艳, 王雪琦, 田宇, 庞亚彤, 黄蓓, 宁平, 李凯(通讯作者). 镧掺杂棒状二氧化铈脱除高炉煤气中有机硫的研究[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2023.08.22.002
引用本文: 资双艳, 王雪琦, 田宇, 庞亚彤, 黄蓓, 宁平, 李凯(通讯作者). 镧掺杂棒状二氧化铈脱除高炉煤气中有机硫的研究[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2023.08.22.002
Study on the Removal of Organic Sulfur from Blast Furnace Gas by La Doped CeO2-R[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2023.08.22.002
Citation: Study on the Removal of Organic Sulfur from Blast Furnace Gas by La Doped CeO2-R[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2023.08.22.002

镧掺杂棒状二氧化铈脱除高炉煤气中有机硫的研究

Study on the Removal of Organic Sulfur from Blast Furnace Gas by La Doped CeO2-R

  • 摘要: COS是高炉煤气中含硫组分最高的污染物,催化水解法是一种最常见的脱除COS的方法。本研究制备了三种不同形貌的CeO2(棒状、正方体状、球状)进行COS脱除,催化剂的表征表明,棒状二氧化铈的(110)晶面更容易产生氧空位,中强碱性位点强度最高,最有利于COS的脱除。在棒状二氧化铈上进一步掺杂La,脱硫稳定性提高1.37倍,表明La掺杂对催化剂的脱硫性能有促进作用。最后,通过CO2-TPD和EPR表征共同证明了碱性位点的数量和强弱与催化活性成正比,在金属氧化物中引入氧空位促进H2O的活化和解离形成羟基提高了COS的水解活性通过XPS探究了催化剂失活的机理。其中,具有更大比表面积的棒状CeO2有利于暴露更多的表面活性位点,掺杂金属La后的CeO2产生更多的氧空位,形成更多的表面羟基;另一方面,碱性中心是催化剂的活性位点,适量的氧空位有助于COS的水解活性;最后,沉积在催化剂表面的硫酸盐是催化剂失活的主要原因。

     

    Abstract: To accelerate the green and low-carbon development of the steel industry, it is urgent to remove sulfur compounds from blast furnace gas. COS is the highest sulfur containing pollutant in blast furnace gas, and catalytic hydrolysis is the most common method for removing COS. This study mainly introduces from three aspects. Firstly, it explores the effects of three different morphologies of CeO2 (rod-shaped, cubic, and spherical) on the performance of COS removal. The characterization of the catalyst shows that the (110) crystal surface of rod-shaped ceria is more prone to generating oxygen vacancies and has the strongest alkaline sites, which is most conducive to the removal of COS. Secondly, the improvement of COS removal performance by La doped CeO2 was investigated, resulting in an increase in desulfurization stability from 240 minutes to 570 minutes and a desulfurization rate increase of about 60%, indicating that La doping has a promoting effect on the desulfurization performance of the catalyst. Finally, the effects of the number and strength of alkaline sites on catalytic activity were jointly demonstrated through characterization such as CO2-TPD, XPS, and EPR. The introduction of oxygen vacancies in metal oxides promoted the activation and dissociation of H2O, and the formation of hydroxyl groups promoted the hydrolysis activity of COS. Among them, having a large specific surface area of CeO2-R may be beneficial for exposing more surface active sites, facilitating the adsorption of CO2 and generating more alkaline sites. On the other hand, CeO2 doped with lanthanum metal generates more oxygen vacancies due to the interaction between metals, promoting the activation and dissociation of H2O to form more hydroxyl groups, which will contribute to the hydrolysis activity of COS; Finally, the sulfate deposited on the surface of the catalyst is the main cause of catalyst deactivation.

     

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