本文關(guān)鍵詞： 合成氣 低碳醇 CTAB-MnCuFe/ZnO Cu-Fe_3C 工藝參數(shù)　出處：《華東理工大學》2017年碩士論文　論文類型：學位論文

【摘要】：合成氣催化制備低碳醇是綜合利用煤、天然氣及生物質(zhì)等能源的有效方法之一。通過對費托合成催化劑的改性來提高低碳醇選擇性及時空收率是此課題研究的重要方向。本研究以Cu-Fe催化劑為基礎(chǔ),考察了 CeO、ZrO_2、Al2O3、MgO和ZnO載體,非堿性金屬 Al、Ce、La、Mg、Ba、Ca、Zr、Cr、Mn、Ti、Co 和 Ni 助劑以及表面活性劑 CTAB、PVP、PEG和SDS對催化劑性能的影響,屬ZnO、Mn和CTAB改性效果最佳。繼而,采用BET、SEM、XRD、TPR、XPS等表征手段研究了三者的改性機制,確定反應的活性中心。研究表明,ZnO載體大大改變了催化劑的物理結(jié)構(gòu),促進了活性組分的分散及其還原能力,低碳醇時空收率為載體中最佳的46mg·L~(-1)·h~(-1)。Mn作為改性效果最佳的金屬助劑,促使高度聚集的CuFe_2O_4分裂形成ZnFe_2O_4和CuMn_2O_4,并在預處理過程中徹底還原成分子態(tài)Fe和Cu,形成合成氣催化反應所需的Cu-Fe_3C雙活性位,改性后低碳醇選擇性及時空收率分別達到了 52%和102mg·L~(-1)·h~(-1)。此外,CTAB改性后低碳醇選擇性提升至56%,其添加強化了 CuO的還原力,Cu0/Cu+比例明顯提高,Cu-Fe_3C雙活性位之間的作用力增強。同時,對MnCuFe/ZnO及CTAB-MnCuFe/ZnO催化劑制備及操作參數(shù)的研究表明,450℃的煅燒溫度、300℃的反應溫度、H2/CO = 2.0的原料配比對低碳醇的制備最有利。
[Abstract]:Synthesis of low carbon alcohols catalyzed by syngas is a comprehensive utilization of coal. One of the effective methods for energy sources, such as natural gas and biomass, is to improve the selectivity and space-time yield of low carbon alcohols by modifying Fischer synthesis catalysts. This research is based on Cu-Fe catalysts. The effects of CEO _ 2O _ 2Al _ 2O _ 3 MgO and ZnO supports, non-alkaline metal Altrocerium laurantium, baccalcium zirconium, and Ni additives, as well as surfactants such as CTABX, PVP, PEG and SDS, on the catalytic properties of the catalysts were investigated. The modification mechanisms of the three catalysts were studied by means of BET-SEMXRDX TPR-TPR-XPS, and the effects of CTAB / ZrO2Al2O3-MgO and SDS on the performance of the catalysts were investigated. The results showed that ZnO support greatly changed the physical structure of the catalyst, promoted the dispersion of active components and their reduction ability, and the space-time yield of low carbon alcohol was the best 46mg 路L ~ (-1) 路hu ~ (-1) 路mn as the metal adjuvant with the best modification effect. The highly aggregated CuFe_2O_4 splits into ZnFe_2O_4 and CuMn2O4, and in the process of pretreatment, the molecular Fe and Cu are completely reduced to form the double active sites of Cu-Fe_3C for the catalytic reaction of syngas. After modification, the selectivity and space-time yield of low carbon alcohols reached 52% and 102 mg 路L ~ (-1) 路h ~ (-1) 路h ~ (-1) respectively. In addition, the selectivity of low carbon alcohols was increased to 56% after modified by CuO. The ratio of Cu _ 0 / Cu _ 0 / Cu to Cu _ 0 / Cu _ 0 / Cu _ 2O _ 2 enhanced the interaction force between Cu _ Fe _ 3C and Cu _ 2O _ 3. The preparation and operation parameters of MnCuFe/ZnO and CTAB-MnCuFe/ZnO catalysts were studied. The results show that the ratio of H _ 2 / CO = 2.0 is the most favorable for the preparation of low carbon alcohols at the calcination temperature of 450 鈩，

本文編號：1534577