磷改性ZSM-5分子筛物化性质和裂解制乙烯性能的研究

The physicochemical features of phosphorus-modified ZSM-5 zeolites (SiO2/Al2O3 molar ratio is 25) were characterized by XRD(X-ray diffraction), BET(Brunauer, Emmett and Teller spcific surface area measurement), NH3-TPD(ammonia temperature-programmed desorption) and MASNMR(magic angle spinning nuclear magnetic resonance), and the performance on catalytic pyrolysis to produce ethylene was investigated with a light hydrocarbon fixed bed micro-reactor with n-octane as feed. The results show that the acid site density, acid intensity and hydrothermal stability of ZSM-5 zeolite were improved by phosphorus modification. When P205 content in ZSM-5 zeolite is higher than 2.5%, phosphorus modification can prevent ZSM-5 zeolite crystal structure transformation from orthorhombic to monoclinic. In addition, the dealumination of ZSM-5 zeolite framework was moderated by phosphorus modification under high temperature hydrothermal treatment. The results of n-octane pyrolysis on phosphorus-modified ZSM-5 zeolites show that ethylene yields of zeolites with different phosphorus content are almost the same under the same n-octane conversion. However, the modified zeolites with higher pyrolysis activity give lower yield of propene, butene and total olefin than lower pyrolysis activity under the same n-octane conversion.     

毛细管膜生物反应器中加沸石对膜污染的影响

通过处理生活污水时毛细管膜污染状况的研究，考察了膜水通量随沸石投加量而变化的情况。在操作压力为0．025MPa，膜面流速为0．8m/s，p(MLSS)为3000mg／L的条件下，与不投加沸石直接处理生活污水相比，沸石的投加使膜水通量上升，总阻力下降；试验还探讨了沸石最佳投加量问题。结果表明，沸石的投加可改善膜面泥饼性质，提高水通量，是一种积极的膜污染防治手段。     

SAPO-34动态脱附特性实验研究

针对吸附材料在太阳能吸附式制冷系统中的应用,利用称重法在高温真空环境下对水的脱附性能进行了实验研究,探究不同温度、压力对SAPO-34沸石分子筛脱附性能的影响.结果表明:温度对材料脱附性能的影响要远大于压力的影响,这在吸附式制冷系统中是非常有利的;当压力一定时,材料的脱附完善度随温度的升高而增大,且不随温度变化均匀分布.温度过高会影响SAPO-34的性能及影响材料的使用寿命;当温度一定时,材料的脱附完善度随着压力的降低而增大,其变化随压力变化分布得较为均匀.     

Preparation of zeolite NaA for CO2 capture from nickel laterite residue

Zeolite NaA was successfully prepared from nickel laterite residue for the first time via a fusion-hydrothermal procedure. The structure and morphology of the as-synthesized zeolite NaA were characterized with a range of experimental techniques, such as X-ray diffraction, scanning electronic microscopy, and infrared spectroscopy. It was revealed that the structures of the produced zeolites were dependent on the molar ratios of the reactants and hydrothermal reaction conditions, so the synthesis conditions were optimized to obtain pure zeolite NaA. Adsorption of nitrogen and carbon dioxide on the prepared zeolite NaA was also measured and analyzed. The results showed that zeolite NaA could be prepared with reasonable purity, it had physicochemical properties comparable with zeolite NaA made from other methods, and it had excellent gas adsorption properties, thus demonstrating that zeolite NaA could be prepared from nickel laterite residue.     

V_2O_5-沸石-活性炭-凹土脱硝催化剂的研制及脱硝性能

稻壳炭化后添加碱液和铝源分别合成了A型、A+X型和X型沸石-活性炭复合材料,加入凹凸棒石黏土成型,采用浸渍法负载V2O5制备V2O5-沸石-活性炭-凹土复合脱硝催化剂。采用XRD、SEM、N2吸附和EDX对样品进行表征,考察载体类型、V2O5含量和反应温度对催化剂低温脱硝活性的影响。结果表明,二元载体和V2O5协同催化脱硝,其脱硝率高于纯凹土制备的脱硝催化剂。催化剂脱硝活性随V2O5含量的增加而降低。反应温度越高,催化剂脱硝活性越高,最佳的反应温度为250℃,温度大于280℃后活性炭被氧化。     

以高岭土为铝源合成ZSM-5分子筛及其CO2吸附性能研究

ZSM-5分子筛具有独特的晶体结构,其已在催化领域表现出优良的性能。同时又因为分子筛孔径分布均一,其晶体孔穴内部极性较强,而表现出良好的吸附性能,能够吸附水和大气中绝大多数的有毒有害物质,是一种可再生、不产生二次污染的新型吸附材料。以热活化的高岭土为铝源,通过增加合成凝胶中外部硅源的添加量来调节样品硅铝比,且在没有无机碱(氢氧化钠)的情况下,以四丙基氢氧化铵(TPAOH)为模板剂,在有机模板剂和晶种的共同作用下,高效合成自堆积ZSM-5分子筛,并将其用于CO₂吸附。结果表明,较优的合成条件为：晶种添加量(w)3%,模板剂TPAOH,n(TPAOH)/n(SiO₂)=0.3,晶化温度170℃,晶化时间2 h,硅铝比15。在该条件下合成的分子筛对CO₂的吸附性能优于商品ZSM-5分子筛。     

粉煤灰制备吸附剂捕集CO2的研究

利用粉煤灰为原料,制备2大类可用于烟气中CO₂捕集的吸附剂。一类是沸石分子筛类吸附剂,利用水热合成法得到A型、X型等沸石分子筛吸附剂。一类是利用粉煤灰制备出适合的多孔载体,使用浸渍法得到固态胺类吸附剂。沸石分子筛对于CO₂主要是物理吸附,吸附容量169~223 mg/g,固态胺吸附剂是利用胺基与CO₂结合介于物理与化学吸附之间,吸附容量108~189 mg/g。实现将粉煤灰以废治废,即可以缓解粉煤灰对环境的影响,也能够实现碳减排,对社会和经济协调发展有利。     

不同填料曝气生物滤池启动挂膜试验研究

不同填料曝气生物滤池在相同条件下进行挂膜试验。进水流向为上流式,挂膜方式为复合接种挂膜,即先用活性污泥闷曝接种,然后逐步提高进水流速,直到滤料表面形成稳定的生物膜。结果表明:33 d后挂膜成功,在温度为16～24℃,水力停留时间(HRT)为1 h,DO为6 mg/L的情况下,陶粒BAF对CODMn和NH3—N的去除率分别为23%和80%;沸石BAF的去除率分别为27%和84%;组合填料BAF去除效果最好,去除率分别为32%和92%。     

生物沸石过滤器用于污水再生利用工程的研究

采用生物沸石过滤器,研究自然挂膜条件下的设备启动过程,并对不同工况下的处理效果进行对比研究,得出较为经济的运行参数。在水力负荷为6.79 m3/(m2.h),气水比为1∶1时,生物沸石过滤器对氨氮、CODCr、浊度的平均去除率分别为66.43%、43.3%、68.73%,出水达到《城市污水再生利用城市杂用水水质》标准。同时对该工艺在低温下的处理效果进行试验研究,当水力停留时间为0.44 h时,氨氮平均去除率为26.25%。     

HDTMA改性沸石吸附水中Cr（VI）研究

摘要：研究以阳离子表面活性剂HDTMA改性天然斜发沸石,制得HDTMA改性沸石,进而研究HDTMA改性沸石对废水中Cr（VI）的吸附特征。结果表明：HDTMAL改性沸石对cr（VI）吸附符合Langmuir等温式和拟二级动力学方程,饱和吸附量为10．99mg／g,吸附主要为化学吸附,但温度、pH值和干扰离-~HDTMA沸石吸附cr（VI）具有明显影响。