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辐照下铁酸锌高温煤气脱硫剂的制备

The Preparation of ZnFe2O4 Hot Coal Gas Desulfurizer under Irradiation

【作者】 问国强

【导师】 米杰;

【作者基本信息】 太原理工大学 , 高分子化学与物理, 2007, 硕士

【摘要】 高温煤气脱硫剂的研制与开发已从单金属氧化物逐渐转移到复合金属氧化物上,其中铁酸锌脱硫剂由于它具有高脱硫精度、高硫容和高反应活性,成为最具代表性的复合金属氧化物脱硫剂。本论文采用在超声波作用下共沉淀得到铁酸锌前驱体,然后在微波辐照下焙烧,制备得到脱硫剂的活性组分铁酸锌,进而以铁酸锌为脱硫剂的活性组分,用高岭土作为结构助剂制备了高温煤气铁酸锌脱硫剂。使用BET、孔容和孔径分布、XRD、SEM等手段对脱硫剂表征。在固定床反应器中模拟煤气气氛下进行了脱硫剂的脱硫过程研究,得到如下结论:1.用超声波辅助共沉淀及微波焙烧法制备铁酸锌是可行的,所制备得到的铁酸锌脱硫剂是一种性能优良的高温煤气脱硫剂。2.在超声波共沉淀过程中得到组分均匀,颗粒细小的铁酸锌前驱体,在微波焙烧下形成了晶形完整的尖晶石结构。得到的铁酸锌晶粒大小均匀,粒径范围在40—60nm,晶粒呈球形。3.用微波辐照制备的铁酸锌与常规方法所制备得到的铁酸锌相比,前者的晶相更完整,晶体粒子更为均匀。表明微波辐照对铁酸锌晶体的结构生成有明显的促进作用。常规方法制备烧结过程需要4小时,而微波辐照焙烧仅为1小时就达到了比较好的效果,大大缩短了烧结时间。4.采用微波辐照制备得到的铁酸锌脱硫剂,与常规方法所得到铁酸锌脱硫剂相比较,两者的比表面积大小基本没有差别,但前者的孔容却提高很多,可达到0.146cm~3/g以上,对提升脱硫效果有很大的帮助。5.采用辐照法得到的铁酸锌高温煤气脱硫剂在固定床脱硫反应中表现出良好的稳定脱硫性能,当进口浓度为3700ppm时,出口浓度保持在14个ppm左右,在25小时脱硫过程中几乎没有波动。6.在固定床硫化实验中表明,较优的脱硫剂的脱硫效率为99.6%以上,具有较高的脱硫效率。

【Abstract】 The research and development of high temperature coal gas desulfurizer have changed gradually from mono-metal oxide into mixed-metal oxide, in which zinc ferrite sorbents have become the typical mixed-oxide desulfurizer, because of its high desulfurization precisior, high sulfur capacity and high reactivity.This thesis adopted coprecipitation under the ultrasonic radiation to get zinc ferrite precursors, then adopted calcinations under microwave irradiation to gain zinc ferrite of active components, and then treated zinc ferrite as active components, and used kaolin as structural additive to get hot gas desulfurizer. The thesis also characterized zinc ferrite desulfurizer by means of pore size distribution, pore volume, BET, XRD, SEM. And the thesis explored desulrization under the fixed bed reactor and simulated coal gas atmosphere. The conclusions are as follows:1. It is feasible to adopt corecipitation under the ultrasonic radiation and calcination under microwave irradiation to get zinc ferrite, and the ZnFe2O4 hot coal gas desulfurizer was prepared, which is excellent high temperature desulfurizer.2. In the process of coprecipitation under the ultrasonic radiation, components uniformity was gained, small particled zinc ferrite precursors formed spinel structrure under microwave irradiation. The zinc ferrite crystal grain gained was well distributed, whose range was from 40-60nm, and the crystal grain appeared global.3. To compare the zinc ferrite gained by microwave irradiation with the zinc ferrite gained by normal methods, the crystal phase of the former is more complete, and the crystal grain is well distributed. The result showed that the microwave irradiation promoted the formation of its configuration. It took 4 hour to gain the zinc ferrite by the normal methods. While it just took only an hour to gain it by microwave irradiation, which greatly shorted the sintering time.4. To compare the zinc ferrite gained by microwave irradiation with the zinc ferrite gained by normal methods, both of the specific surface area are to some extent identical, but the pore volume of the former was improved a lot ,up to 0.146cm3/g, which gave great help to improving desulfurization effect.5. The zinc ferrite gained by irradiation showed good and stable property in the process of desulfurization experiment. When the concentration of inlet is 3700ppm, that of outlet keeps about 14ppm, there is almost no fluctuation in 25 hours.6. The result showed the desulfurization efficiency of the excellent desulfurizer is 99.6% in the fixed reactor experiment, which is very high.

  • 【分类号】TQ546.5
  • 【被引频次】1
  • 【下载频次】136
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