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1.
研究了H2CO2CH4CO混合气在活性炭(AC)和分子筛(MS)上的变压吸附(PSA)过程,各组分在AC上的吸附能力为:CO2的大于CH4的,CH4的大于CO的;在MS上为:CO的大于CH4的。并研究了混合气在ACMS复合床层上的PSA过程,其中AC充填于进口端,主要吸附CO2和CH4;MS主要吸附CO,为复合床层PSA过程的模拟计算和设计提供了基础。  相似文献   

2.
通过CO脉冲化学吸附以及对吸附态CO和co+H_2反应进行程序升温表面反应(TPSR),发现1%Ru/siO_2和1%Ru/AL_2O_3催化剂的CO吸附量随焙烧温度的升高而降低。且根据513K和室温吸附co的TPSR不同,认为存在两类不同活性中心。Ⅰ类中心:金属钌与载体的相互作用弱,易吸附CO;Ⅱ类中心:金属与载体的相互作用强,较难吸附CO。随焙烧温度升高,金属与载体作用增强,Ⅱ类中心增多。在微型流动反应器上CO中压加氢发现经673K焙烧的样品的活性及长链烃的生成量和烯/烷比均大于120℃烘干的样品,因此认为,Ⅰ类中心为加氢中心,Ⅱ类中心为链增长中心。  相似文献   

3.
研究了以高锰酸钾或重铬酸钾/水/浓硫酸=5∶8∶100(质量比)或20%(质量分数)的过硫酸铵水溶液及氯化铁或硫酸铜作为催化剂对聚烯烃进行的表面氧化处理,并通过熔点和红外光谱及光电子能谱等方法对氧化反应和产品的结构进行了表征。研究表明,最佳氧化温度和时间分别为45℃~60℃与45min;用KMnO4/H2SO4/FeCl3/CuSO4,K2Cr2O7/H2SO4/FeCl3,K2Cr2O7/H2SO4/CuSO4体系对聚乙烯的氧化中,氧化深度依次减小,C原子的摩尔分数由未氧化时的80.804%,分别降低为31.907%、69.905%和78.669%;在FeCl3催化下,产品中Cl的含量普遍增加,而以KMnO4/H2SO4/FeCl3/CuSO4氧化时增加最多,但对K2Cr2O7/H2SO4/FeCl3氧化体系,O含量的增加相对较多  相似文献   

4.
CaSO4-H3PO4-H2SO4-H2O四元系统及其应用(下)吴佩芝(上海天山路468弄9号304室200051)中图分类号TQ126.353四元系统在二水物流程中的应用〔1〕CaSO4-H3PO4-H2O三元系统研究的结果指出:形成二水物硫酸钙的...  相似文献   

5.
吴佩芝 《磷肥与复肥》1997,12(5):31-36,64
CaSO4-H3PO4-H2SO4-H2O四元系统是湿法磷酸领域中的主要相图,直到1958年才由日本学者池野亮当等人*首先发表,而且只是其中关于CaSO4·12H2OCaSO4·2H2O转化过程部分的研究结果。70年代中,笔者在研究半水—二水再结晶流程时发现:在温度恒定的条件下,四元系统中的CaSO4·12H2OCaSO4·2H2O转化过程的平衡点轨迹呈线性,可以用直线方程式计算有关参数,扩大了它的意义。随后,笔者在进行半水—二水再结晶流程的中试时,曾用上述计算参数控制CaSO4·12H2O—→CaSO4·2H2O转化过程中二水物结晶的形成,取得满意结果。  相似文献   

6.
采用TG-DTA,IR,XRD和NMR对ALC(压蒸轻质混凝土)废渣中添加氢氧化钙后的ALC-CH系统,在水热处理过程中的物理化学变化进行了分析,同时用BET方法测定了不同温度水热处理物的比表面积。结果表明,ALC渣添加适量氢氧化钙,经140~200℃下水热处理3h的水热处理物理中形成了新的水化硅酸钙α-C2SH.α-C2SH的形成量随水热处理温度的提高而增加。水热处理物的比表面积波动于12~22  相似文献   

7.
比较不同NaCl、Ca2+、PO3-4等离子浓度对嗜盐隐杆藻(Aphanothecehalophytica)细胞生长及胞外多糖(Exopolysac-charideEPS)产量的影响。在各影响因子不同浓度的培养条件下,0.5mol/L的NaCl、1.0g/L的Ca(NO3)2·4H2O、0.1g/L的KH2PO4分别是其最佳生长浓度。EPS的产量在0.5mol/LNaCl、,0.5g/LCa(NO3)2·4H2O、0.5g/L的KH2PO4培养条件下最高。在较低的Ca2+、Mg2+、PO3-4浓度下可提高EPS产率。  相似文献   

8.
活性炭纤维的热处理及其氧化还原吸附银的研究   总被引:1,自引:0,他引:1  
剑麻基磷酸化学活化活性炭纤维(SACFP)在惰性气氛中热处理后,纤维表面的化学结构和物理形态发生改变。随处理温度升高,O/C比先减小再略有回升,而比表面积增大。XPS分析表明纤维的C1s,O1s峰位基本不变,与碳相关的含氧官能团总量有一低谷,与元素分析的结果一致,O1s峰在低结合能端出现明显的肩峰变化;而P2p峰位向低结合能方向移动,P/C比则出现一峰值。实验表明:纤维比表面积比氧化还原吸附前有所增大;且随热处理温度升高,对Ag+的还原吸附量增大,并趋于定值,所得纳米银的平均晶粒尺寸略有减小。  相似文献   

9.
乙酸异丁酯合成中无机盐催化作用初探   总被引:10,自引:1,他引:10  
研究了CuSO4.5H2O2、CuSO4、FeSO4、7H2O、FeCl3、6H2O、CuCl2.2H2O等5种盐对异丁醇与乙酸酯化反应的催化性能,结果表明FeCl3.6H2O和CuCl2.2H2O是较好的催化剂,酯转化率达86-93%。  相似文献   

10.
报道了N,N-二辛基甘氨酸从盐酸体系中萃取铑的机理.结果表明:铑的萃取率随酸度、氯离子浓度、铑离子浓度的增大而降低.采用斜率法测得萃合物组成为:R2NCH2COOHHRh(H2O)2Cl4.萃取反应方程式为:R2NCH2COOH.HCl(O)+Rh(H2O)2Cl-4(A)=R2NCH2COOH.HRh(H2O)2Cl4(O)+Cl  相似文献   

11.
负载金属改性活性炭纤维的脱硫性能   总被引:6,自引:0,他引:6  
Metal-loaded activated carbon fibers (ACFs) were prepared by impregnation and characterized by N2 adsorption at 77K, XRD, XPS and SEM. Their properties on SO2 removal were examined in a tubular fixed bed reactor with a model flue gas. Cobalt-loaded ACF showed the best activity among the prepared metal-loaded ACFs and a constant removal ratio of SO2 above 87% during continuous exposure to the flow of SO2/O2/H2O/N2 at 45℃ for more than 216h. The characteristic of the prepared loaded-ACFs showed that the exceptional activity of Co-ACF was attributed to the high amount of active sites due to modification by loading cobalt.  相似文献   

12.
用SO24-物质的量相同的H2SO4和Al2(SO4)3分别对Al-MCM-41进行改性,得到样品SO42-/Al-MCM-41和Al/SO24-/Al-MCM-41。采用X射线多晶衍射(XRD)、红外光谱(FTIR)、N2吸附-脱附和NH3程序升温脱附(NH3-TPD)等测试技术对样品进行表征。分别用H2SO4、MCM-41、Al-MCM-41、SO42-/Al-MCM-41和Al/SO24-/Al-MCM-41催化合成丙酸香叶酯,比较了它们的催化性能。结果表明,H2SO4和Al2(SO4)3改性对Al-MCM-41中孔分子筛结构影响不明显,都可提高其酸性,改性后中孔分子筛的骨架仍保持着六方介孔结构,孔径、孔容和比表面积有所降低,但用Al2(SO4)3改性的分子筛酸性和催化性能更强;SO42-/Al-MCM-41的酸催化活性主要源于SO42-与分子筛表面硅羟基作用形成的双齿螯合配位结构,而Al/SO42-/Al-MCM-41的酸催化活性一方面来自SO24-与分子筛表面硅羟基作用形成的双齿螯合配位结构,另一方面,也来自与分子筛骨架接枝的铝,使其产生了更多的Brnsted酸中心。  相似文献   

13.
Fe/AC脱硫剂的还原再生   总被引:1,自引:1,他引:0  
研究了Fe/AC脱硫剂在不同气氛中的再生行为,并对再生后Fe/AC二次脱硫活性差异的原因进行了探讨,结果表明:脱硫剂经H2再生后二次脱硫活性与初活性相比明显下降,经NH3在350C再生后二次脱硫活性与初活性相比未见下降,以NH3再生后Fe/AC脱硫活性的改善并非是脱硫剂对NH3吸附所造成的表面碱性的提高,而应归因于还原性较弱的NH3仅将Fe2(SO4)3中的SO4^2-选择性还原为SO2 而未与Fe^3 发生反应,从而保证了活性组分在AC表面的高分散性.  相似文献   

14.
Activity behavior of CO oxidation was studied over samaria-doped ceria (SDC)-supported CuO catalysts. The material properties of the SDC support were changed by heat treatments, which were carried out by the variations of the calcination temperatures of SDC (500–1100°C) and the cooling methods (with quenching after calcination or without it). The X-ray diffraction, N2 physisorption, N2O chemisorption, energy dispersive X-ray spectrum, carbon monoxide temperature-programmed reduction, and the activity test were carried out. The results showed that, when the calcination temperature of SDC was lower, its surface area was higher, and thus more interfacial active sites were formed over the CuO/SDC catalyst; this led to higher activity. Quenching after calcination was beneficial to increase the surface area of SDC and thus increase the activity of the CuO/SDC catalyst. It was also found that the specific activity of the interfacial active site was not affected by the heat treatment. The light-off of the CO oxidation activity of the CuO/SDC catalyst was observed at a temperature as low as 75°C. It was concluded that the concentration of the interfacial active sites was key for the occurrence of light-off.  相似文献   

15.
以硫酸为浸取剂对磷石膏进行热浸处理,采用石灰乳中和调节磷石膏酸度,考察了反应温度、反应时间和硫酸浓度对磷石膏中杂质磷、氟、铁和铝的脱除情况的影响。同时,采用扫描电镜、热重分析仪和X射线衍射仪分析了处理前后磷石膏形貌、热稳定性和晶型结构的变化。结果表明:温度为85 ℃,硫酸质量分数为30%,反应45 min时,磷和氟的脱除率均能达到90%左右,铝脱除率能达到80%,铁脱除率大于20%,石膏pH≥7.0。处理后的石膏粒径减小非常明显,热稳定性有一定提高,且晶型更加稳定,能够完全满足建筑材料的要求。  相似文献   

16.
Nitric oxide(NO) removal and sulfur dioxide(SO_2) removal by sodium persulfate(Na_2S_2O_8) were studied in a Bubble Column Reactor. The proposed reaction pathways of NO and SO_2 removal are discussed. The effects of temperatures(35–90 °C), Na_2S_2O_8(0.05–0.5 mol·L~(-1)), Fe SO4(0.5–5.0 m mol·L~(-1)) and H_2O_2(0.25 mol·L~(-1))on NO and SO_2 removal were investigated. The results indicated that increased persulfate concentration led to increase in NO removal at various temperatures. SO_2 was almost completely removed in the temperature range of 55–85 °C. Fe~(2+)accelerated persulfate activation and enhanced NO removal efficiency. At 0.2 mol·L~(-1) Na_2S_2O_8 and 0.5–1.0 mmol·L~(-1) Fe~(2+), NO removal of 93.5%–99% was obtained at 75–90 °C, SO_2 removal was higher than 99% at all temperatures. The addition of 0.25 mol·L~(-1) H_2O_2 into 0.2 mol·L~(-1) Na_2S_2O_8 solution promoted NO removal efficiency apparently until utterly decomposition of H2 O2, the SO_2 removal was as high as98.4% separately at 35 °C and 80 °C.  相似文献   

17.
采用浸渍法制备了CuCoOx/TiO2催化剂,并用XRD、TPR和BET进行了表征。350 ℃焙烧的催化剂CuCoOx/TiO2具有CuCo2O4尖晶石结构,比表面积大,对CO的催化氧化效果好,在110 ℃时可将1%的CO完全氧化成CO2。考察了催化剂焙烧温度、反应温度、CO进口浓度、空速对催化剂催化氧化CO性能的影响。该CuCoOx/TiO2催化剂具有良好的单独抗水和抗硫性能,可用于不同时存在二氧化硫和水的废气脱除CO。  相似文献   

18.
杨师棣  汤发有 《化学试剂》2001,23(3):180-181
研究了H3PW12O40/C体系对丙烯酸和三甘醇的催化酯化反应,通过对活化温度、共沸剂、催化剂的用量及酸醇摩尔比等因素的优化,酯化率可达91.7%,产品纯度大于98%,并且催化剂可以重复使用多次。  相似文献   

19.
Highly active MCM-41 supported nickel phosphide catalysts for hydrodesulfurization(HDS) were synthesized by two different phosphorus sources, in which the surface of Ni_2P catalysts were modified by air instead of being passivated by O_2/N_2 mixture. In addition, the catalysts need not be activated with flowing H_2(30 ml·min~(-1))at 500 °C for 2 h prior to reaction as traditional method. X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), N_2-adsorption specific surface area measurements and CO chemisorption were used to characterize the resulting catalysts. The effect of modification with air on the surface of the catalysts for HDS performance was investigated. Results showed that the surface modification with air can promote the formation of smaller Ni_2P particles and more active Ni sites on surface of catalysts. At 3.0 MPa and 613 K, the dibenzothiophene(DBT)conversion of the catalysts modified with air was 98.7%, which was 7.1% higher than that of catalyst passivated by O_2/N_2 mixture. The higher activities of Ni_2P(x)/M41-O catalysts can be attributed to the smaller Ni_2P particles sizes and the increased hydrogen dissociation activity due to the surface modification.  相似文献   

20.
沥青加萘调制过程中引入与沥青等质量的富氮化合物三聚氰胺,然后经球化、氧化、炭化和H_2O活化制备得到具有一定含氮官能团的沥青基球形活性炭,利用热重、N_2吸附仪和X-射线光电子能谱等手段研究了氧化沥青球的炭化、活化行为,考察了活化样品的孔隙结构、元素组成和表面化学性质。结果表明,三聚氰胺的引入丰富了沥青基球形活性炭的表面化学性质,使其同时具备明显的含氧和含氮官能团,其中含氮官能团主要以吡啶、吡咯和氮氧化合物形式存在;此外,三聚氰胺的引入提高了炭化沥青球在活化过程中与H_2O的反应速率,从而得到孔隙结构更为发达的沥青基球形活性炭。  相似文献   

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