本文選題：氧化銅基復合脫硫劑　切入點：三維有序大孔　出處：《太原理工大學》2017年碩士論文　論文類型：學位論文

【摘要】：面對日趨嚴重的環(huán)境污染問題和逐步嚴苛的空氣保護法,提高能源利用率,開發(fā)高效、綠色、節(jié)能的新技術已迫在眉睫。燃料電池是其中突出的代表。氫燃料電池的興起使得常低溫脫硫走入人們的視野。為了滿足燃料電池正常運行,必須對提供燃料電池的富氫氣體進行脫硫。金屬氧化物吸附脫硫因脫硫精度高、工藝操作簡單而被廣泛采用。其中,氧化銅和氧化鋅脫硫的熱力學優(yōu)勢明顯,具有很高的脫硫精度,然而常溫操作條件下存在活性差、硫容低的問題。基于前期的研究結果,本研究將通過織構優(yōu)化與表面改性的方法來提高氧化銅基脫硫劑對硫化氫的硫化常溫脫硫性能。本研究采用膠晶模板法制得三維有序大孔銅硅及銅鋅硅復合脫硫劑,并用氨氣相沉積法和堿浸漬法對表面進行改性,在固定床反應器上對所制備的脫硫劑進行穿透動態(tài)評價實驗。采用掃描電子顯微鏡(SEM)、透射電子顯微鏡(TEM)、X射線衍射儀(XRD)、氮吸附(BET)、CO_2程序升溫脫附(CO_2-TPD)、X光電子能譜(XPS)、X射線吸收近邊結構(XANES)、熱重質譜聯(lián)用(TG-MS)一系列儀器進行表征,得到以下結論:SEM/TEM、XRD和氮吸附相關表征表明,具有三維有序大孔結構的脫硫劑大孔結構整齊有序,三維空間相互貫通,晶粒高度分散,比表面積大。二氧化硅的加入助于三維有序大孔骨架牢固,同時對活性金屬氧化物起到分散作用。固定床穿透脫硫實驗評價結果表明,三維有序大孔的特殊結構可使得銅硅復合脫硫劑的硫容提升六倍之多,突出體現(xiàn)了大孔在脫硫過程中的作用。硫化過程中水汽的加入對脫硫劑硫化性能起到了至關重要的作用,水膜的形成為硫化氫在金屬氧化物表面的解離吸附提供了極大幫助。在相對濕度為47.6%時,脫硫劑的脫硫性能最佳,硫容達到147 mg/g。然而,由于熱力學平衡所限,水汽的加入?yún)s使脫硫精度有一定降低。通過對脫硫劑表面進行氨化/堿化改性,可克服上述缺點,顯著提高脫硫劑在有水氣氛下的脫硫性能,使精度和硫容均有大幅提高。硫化/再生循環(huán)性能的考察研究表明,具有三維有序大孔的脫硫劑在不同溫度下再生,均具有比非三維有序大孔脫硫劑更好的活性。在300℃再生后脫硫劑具有最佳的再生性能,并在硫化再生循環(huán)過程中保持高硫容。通過對銅鋅硅復合脫硫劑的研究,發(fā)現(xiàn)銅鋅硅復合脫硫劑的硫容介于鋅硅復合脫硫劑和銅硅復合脫硫劑之間。在銅鋅硅系復合脫硫劑中,1%的銅與鋅硅復合后的脫硫劑具有最高的硫容,由此可知金屬間的相互作用對其硫化性能有重要影響。
[Abstract]:In the face of increasingly serious environmental pollution problems and gradually stringent air protection laws, to improve energy efficiency, to develop efficient, green, New energy-saving technology is imminent. Fuel cell is one of the outstanding representatives. The rise of hydrogen fuel cell makes desulfurization at low temperature into people's view. In order to meet the normal operation of fuel cell, It is necessary to desulphurize the hydrogen rich body which provides fuel cell. Metal oxide adsorption desulfurization is widely used because of its high desulfurization precision and simple operation. Among them, the thermodynamic advantages of copper oxide and zinc oxide desulfurization are obvious. It has high desulphurization accuracy, however, there are some problems such as low activity and low sulfur capacity under normal operating conditions. In this study, the desulfurization performance of cupric oxide based desulfurizer on hydrogen sulfide at room temperature was improved by texture optimization and surface modification. In this study, three dimensional ordered macroporous copper-silicon and copper-zinc silicon composite desulfurizer were prepared by colloidal template method. The surface was modified by ammonia vapor deposition and alkali impregnation. The dynamic penetrability evaluation experiment of the prepared desulfurizer was carried out in a fixed bed reactor. Using scanning electron microscope (SEM), transmission electron microscope (TEM), Tem X ray diffractometer (XRDX), nitrogen adsorption (BETT) COS2, temperature programmed desorption of CO2-TPDX (X ray photoelectron spectroscopy) XPSX X ray diffraction (XPSX). The absorption near edge structure was characterized by a series of TG-MS instruments, which were characterized by thermogravimetric mass spectrometry (TG-MS). The following conclusions are obtained: XRD and nitrogen adsorption characterization show that the macroporous structure of desulfurizer with three-dimensional ordered macroporous structure is orderly, the three-dimensional space is interpenetrating, and the grains are highly dispersed. The addition of silica helps the three-dimensional ordered macroporous skeleton to be firm and disperses the active metal oxides. The experimental results of fixed bed penetration desulfurization show that, The special structure of three-dimensional ordered macroporous can increase the sulfur capacity of copper-silicon composite desulfurizer by six times, which highlights the role of macropore in the desulfurization process. The addition of water vapor plays an important role in the vulcanization performance of the desulfurizer. The formation of water film provides a great help for the dissociation and adsorption of hydrogen sulfide on the surface of metal oxides. When the relative humidity is 47.6, the desulfurization performance of the desulphurizer is the best, and the sulfur capacity is up to 147 mg / g. However, due to the thermodynamic equilibrium, The desulphurization precision is reduced by adding water vapor. The desulfurization performance of the desulfurizer in the presence of water can be greatly improved by ammoniation / alkali modification on the surface of the desulfurizer, which can overcome the above shortcomings and improve the desulfurization performance of the desulphurizer in the presence of water. The results show that the desulphurizer with three dimensional ordered macroporous is regenerated at different temperatures. After regeneration at 300 鈩，

本文編號：1567183