邻氨基苯甲醚的清洁生产工艺

采用清洁生产的理论与思维模式,对合成邻氨基苯甲醚的传统工艺进行了改造,开发出以质量分数5％的Pd／C为催化剂、加氢制备邻氨基苯甲醚的清洁生产工艺。最佳生产工艺条件为：100g邻硝基苯甲醚中加入0．9g催化剂、溶剂与邻硝基苯甲醚的质量比0．75、反应压力0．7MPa、反应温度80℃。与传统的硫化钠还原工艺相比,该工艺使反应时间由6h缩短到1．75h,产品收率由90．5％提高到93．8％,解决了原工艺产生大量含硫废水的问题,每吨产品的生产成本可降低1650元。     

负载型TiO2在印染废水降解中的失活及原因分析

研究了负载型TiO2光催化剂在印染废水降解中的失活及其产生的原因.实验结果说明,催化剂活性下降的主要原因有废水中不溶于水的染料等悬浮物和催化反应中产生的无定形碳在催化剂表面的吸附;高含量的无机离子对催化剂活性位的占据或在表面的沉积;长时间的使用和反复冲洗使TiO2负载量减少.通过同时采用灼烧和酸洗的方法可以使TiO2的活性恢复到新催化剂的69.5%.     

活性炭复合床层对动活性的影响试验

本文通过对KZ1床层、KZ2床层、KZ1和KZ2复合床层在不同床层厚度条件下,对氯化氰蒸气的动活性进行对比试验,并对试验结果进行分析,得出了后者并非前两者之和,而有了大幅提高的结论。     

新型L沸石在FCC汽油加氢脱硫催化剂中的应用研究

采用等体积浸渍法,制备了一系列含有相同含量活性组分(MoO3、CoO和NiO)不同USL沸石含量的加氢脱硫催化剂。通过X-射线衍射(XRD)、氮气吸附脱附、吡啶红外(Py-FTIR)和氨气程序升温脱附(NH3-TPD)等分析方法对样品进行了表征。结果表明:与Cat.0(参比剂,仅以γ-Al2O3为载体)相比,添加USL沸石催化剂所得加氢油的烯烃含量、芳烃含量和研究法辛烷值(RON)均增加;仅当催化剂载体中USL沸石加量在0~40m%之间变化时,加氢油的异构烷烃含量呈上升趋势;而当载体中USL沸石添加量在0~20m%之间变化时,催化剂的脱硫率有所升高。综合对比,当载体中USL沸石添加量约为40m%,催化剂具有最佳的综合性能指标,脱硫率达90%,RON损失仅为1.5左右。     

Heterogeneous activation of persulfate by CuMgAl layered double oxide for catalytic degradation of sulfameter

In this study, a series of CuMgAl layered double oxides (CuMgAl-LDOs) were obtained via calcination of CuMgAl layered double hy-droxides (CuMgAl-LDHs) synthesised via a co-precipitation method. The results show that CuMgAl-LDO can be prepared using an optimal Cu:Mg:Al molar ratio of 3:3:2, NaOH:Na2CO3 molar ratio of 2:1, and calcination temperature of 600 °C. CuMgAl-LDO is a char-acteristic of mesoporous material with a lamellar structure and large specific surface area. The removal efficiency of sulfameter (SMD) based on CuMgAl-LDO/persulfate (PS) can reach>98％over a wide range of initial SMD concentrations (5–20 mg L-1). The best removal efficiency of 99.49％was achieved within 120 min using 10 mg L-1 SMD, 0.3 g L-1 CuMgAl-LDO, and 0.7 mmol L-1 PS. Kinetic analysis showed that the degradation of SMD was in accordance with a quasi-first-order kinetic model. The stability of the CuMgAl-LDO catalyst was verified by the high SMD removal efficiency (> 97％ within 120 min) observed after five recycling tests and low copper ion leaching concentration (0.89 mg L-1), which is below drinking water quality standard of 1.3 mg L-1 permittable in the U.S. Radical scavenging experiments suggest that SO·4- is the primary active species participating in the CuMgAl-LDO/PS system. Moreover, our mechanistic investigations based on the radical scavenging tests and X-ray photoelectron spectroscopy (XPS) results indicate that Cu(II)–Cu(III)–Cu(II) circulation is responsible for activating PS in the degradation of SMD and the degradation pathway for SMD was deduced. Accordingly, the results presented in this work demonstrate that CuMgAl-LDO may be an efficient and stable catalyst for the activation of PS during the degradation of organic pollutants. ? 2020, Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communi-cations Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).     

金属负载活性炭催化剂的稳定性研究

通过预处理、浸渍处理、改性液后处理等方式,研究开发出具有电化学反应性能的系列金属负载活性炭催化剂.分别将未改性和改性后的系列金属负载活性炭用于不同pH值下多种高浓度有机废水处理.试验结果表明,改性后的载铜及载铁活性炭催化剂经催化氧化反应后,处理出水中Cu2+离子和Fe2+离子的溶出量均可减少90％以上,苯胺及苯酚废水中COD的去除率可达50％～95％.大大提高了金属负载活性炭催化剂的稳定性,提高了催化剂的使用寿命,降低了废水处理成本.     

整体蜂窝陶瓷催化剂催化氧化法脱除低浓度VOCs的实验研究

本文讨论了目前有机污染物脱除的各种方法 ,并将催化活性组分担载在经Al2 O3 修饰的整体蜂窝陶瓷支撑体上 ,制备了催化氧化法脱除低浓度有机污染物 (VOCs)ZDL - 1催化剂 ,在固定床反应器进行了连续工艺条件实验。结果表明 ,ZDL 1催化剂具有低温启动性能好、脱除VOCs的效率高、稳定性好的突出优点 ,且床层压降低。为ZDL 1催化剂应用于不同过程脱除VOCs提供基础     

Selective oxidation of benzyl alcohols to benzoic acid catalyzed by eco-friendly cobalt thioporphyrazine catalyst supported on silica-coated magnetic nanospheres

A novel magnetically recoverable thioporphyrazine catalyst (CoPz(S-Bu)8/SiO2@Fe3O4) was prepared by immobilization of the cobalt octkis(butylthio) porphyrazine complex (CoPz(S-Bu)8) on silica-coated magnetic nanospheres (SiO2@Fe3O4). The composite CoPz(S-Bu)8/SiO2@Fe3O4 appeared to be an active catalyst in the oxidation of benzyl alcohol in aqueous solution using hydrogen peroxide (H2O2) as oxidant under Xe-lamp irradiation, with 36.4% conversion of benzyl alcohol, about 99% selectivity for benzoic acid and turnover number (TON) of 61.7 at ambient temperature. The biomimetic catalyst CoPz(S-Bu)8 was supported on the magnetic carrier SiO2@Fe3O4 so as to suspend it in aqueous solution to react with substrates, utilizing its lipophilicity. Meanwhile the CoPz(S-Bu)8 can use its unique advantages to control the selectivity of photocatalytic oxidation without the substrate being subjected to deep oxidation. The influence of various reaction parameters on the conversion rate of benzyl alcohol and selectivity of benzoic acid was investigated in detail. Moreover, photocatalytic oxidation of substituted benzyl alcohols was obtained with high conversion and excellent selectivity, specifically conversion close to 70%, selectivity close to 100% and TON of 113.6 for para-position electron-donating groups. The selectivity and eco-friendliness of the biomimetic photocatalyst give it great potential for practical applications.     

Catalytic removal of phenol from gas streams by perovskite-type catalysts

Three perovskite-type catalysts prepared by citric acid method are applied to remove phenol from gas streams with the total flow rate of 300 mL/min, corresponding to a GHSV of10,000/hr. LaMnO_3 catalyst is first prepared and further partially substituted with Sr and Cu to prepare La_(0.8)Sr_(0.2)MnO_3 and La_(0.8)Sr_(0.2)Mn_(0.8)Cu_(0.2)O_3, and catalytic activities and fundamental characteristics of these three catalysts are compared. The results show that phenol removal efficiency achieved with La_(0.8)Sr_(0.2)Mn_(0.8)Cu_(0.2)O_3 reaches 100% with the operating temperature of 200°C and the rate of mineralization at 300°C is up to 100%, while the phenol removal efficiencies achieved with La_(0.8)Sr_(0.2)MnO_3 and LaMnO_3 are up to 100% with the operating temperature of 300°C and 400°C, respectively. X-ray photoelectron spectroscopy(XPS) analysis shows that the addition of Sr and Cu increases the lattice oxygen of La_(0.8)Sr_(0.2)Mn_(0.8)Cu_(0.2)O_3, and further increases mobility or availability of lattice oxygen. The results indicate that La_(0.8)Sr_(0.2)Mn_(0.8)Cu_(0.2)O_3 has the best activity for phenol removal among three catalysts prepared and the catalytic activity of phenol oxidation is enhanced by the introduction of Sr and Cu into LaMnO_3. Apparent activation energy of 48 k J/mol is calculated by Mars–Van Krevelen Model for phenol oxidation with La_(0.8)Sr_(0.2)Mn_(0.8)Cu_(0.2)O_3 as catalyst.     

轻型车NH_3排放实验研究

用傅里叶变换紫外光谱法对4辆不同里程、不同排量、不同排放标准的轻型车NH_3排放进行测量,试验车辆包括2辆双燃料出租车。实验结果表明:里程数越高的车辆,在同一个测试循环中产生的NH_3排放越多;在高速工况下,车辆产生的NH_3要高于在低速工况时;在循环中车辆加速过程产生的NH_3浓度较高;对于天然气燃料车辆,市区运转工况下基本上没有NH_3排放,在城郊运转工况下产生的NH_3要多于用汽油燃料时。