N-TiO_2/RGO催化剂的制备及其光催化性能的研究

以三乙胺为氮源,HF为形貌控制剂,采用水热法一步合成了N掺杂(001)面锐钛矿TiO_2纳米片/还原氧化石墨烯(N-Ti O2/RGO)复合催化剂,通过XRD、FTIR、SEM、TEM和Raman对样品的组成结构和形貌进行表征。以罗丹明B(Rh B)为模拟污染物,研究了不同掺N量和氧化石墨烯加入量下制备的复合材料的光催化性能。实验结果表明:当n(N)∶n(Ti)为0.5,氧化石墨烯加入量为15 m L时,N-TiO)2/RGO复合材料的光催化性能最好。在催化剂用量为0.5 g/L,罗丹明B溶液初始浓度为20 mg/L时,紫外光催化反应30 min后,罗丹明B的降解率可达94.02%。     

废SCR脱硝催化剂中钨和钒的浸出实验研究

废SCR脱硝催化剂中钨和钒的浸出是实现其回收的关键.采用碳酸钠混合焙烧-稀硫酸浸出法,对废SCR脱硝催化剂中金属钨和钒的浸出实验进行了研究,考察了焙烧温度t_1(℃)、焙烧时间t_2(h)、硫酸浓度c(v/v)、液固比w、浸出温度t_3(℃)、浸出时间t_4(h)、Na_2CO_3与催化剂的质量比m(Na_2CO_3)/m(催化剂)等因素对钨和钒浸出率的影响.结果表明,在t_1为800℃、t_2为3 h、c为2%、w为8:1、t_3为80℃、t_4为4 h、m(Na2CO3)/m(催化剂)为1.2的反应条件下,废SCR脱硝催化剂中钨和钒的浸出率可分别高达99.08%、98.49%,为后续钨和钒的高效提取与回收提供了有利的条件.     

Application of TiO2 nanoparticles for eco-friendly biodiesel production from waste olive oil

An environmentally benign, simple, and efficient process has been developed for biodiesel production from waste olive oil in the presence of a catalytic amount of TiO₂ nanoparticles at 120°C with a conversion of 91.2% within 4 h. The present method affords nontoxic and noncorrosive medium, high yield of biodiesel, clean reaction, and simple experimental and isolation procedures. The catalyst can be recycled by simple filtration and reused without any significant reduction in its activity.     

Release characteristics and control of nitrogen,phosphate, organic matter from spent mushroom compost amended soil in a column experiment

Spent mushroom compost (SMC) is a co-product of edible mushroom which contains abundant nutrients including organics, nitrogen (N) and phosphorous (P). This study is related to the release potential of nitrogen, phosphate and organic matter from SMC amended soil in column-based experiments. Results showed that due to SMC application, NH₄⁺–N and NO₃⁻–N concentrations in leachate decreased by 92.5% and 76.3%, respectively, while EC and COD_Cr concentrations increased by 84.2% and 481.9%, respectively, as compared to chemical fertilizers. Moreover, a minor loss of TN_cum (65%) and TP_cum (almost equal value) exhibited good nutrient retention capacity. Leaching test results demonstrated that the mixed application of SMC and chemical fertilizers could alleviate excessive COD_Cr level in SMC leachate. The release process of nutrients in SMC amended soil could be described by first/first order mixed model, indicating that nutrients leached from SMC follow a two-stage pattern.     

Role of NO in Hg oxidation over a commercial selective catalytic reduction catalyst V2O5–WO3/TiO2

Experiments were conducted in a fixed-bed reactor that contained a commercial catalyst, V₂O₅–WO₃/TiO₂, to investigate mercury oxidation in the presence of NO and O₂. Mercury oxidation was improved by NO, and the efficiency was increased by simultaneously adding NO and O₂. With NO and O₂ pretreatment at 350°C, the catalyst exhibited higher catalytic activity for Hg⁰ oxidation, whereas NO pretreatment did not exert a noticeable effect. Decreasing the reaction temperature boosted the performance of the catalyst treated with NO and O₂. Although NO promoted Hg⁰ oxidation at the very beginning, excessive NO counteracted this effect. The results show that NO plays different roles in Hg⁰ oxidation; NO in the gaseous phase may directly react with the adsorbed Hg⁰, but excessive NO hinders Hg⁰ adsorption. The adsorbed NO was converted into active nitrogen species (e.g., NO₂) with oxygen, which facilitated the adsorption and oxidation of Hg⁰. Hg⁰ was oxidized by NO mainly by the Eley–Rideal mechanism. The Hg⁰ temperature-programmed desorption experiment showed that weakly adsorbed mercury species were converted to strongly bound ones in the presence of NO and O₂.     

Co、Ni掺入对Pd-Rh型催化剂三效净化C_3H_8、CO、NO的影响

以堇青石质陶瓷蜂窝为第一载体,活性氧化铝和铈锆复合氧化物固溶体涂层为第二载体,采用等体积浸渍法制备系列低Pd-Rh含量的三效催化剂及Co、Ni单或双掺入样品。主要研究了Co、Ni掺入对Pd-Rh型催化剂三效净化C3H8、CO、NO活性的影响,结果表明:同时掺入Co、Ni催化剂的三效净化效果优于单独掺入Co或Ni的三效净化效果,同时掺入Co、Ni时,掺入1%Co3O4和2%Ni O的催化剂净化效果最佳;350℃时,催化脱除C3H8、CO的效率分别为100%、97%,400℃时,催化脱除NO的效率为99%。     

运用模糊层次分析法评价关键装置要害部位

针对目前关键装置要害部位的安全技术报告中只进行定性评估的不足,运用模糊层次分析法对催化裂化装置进行了评价,评价结果对改进关键装置要害部位安全管理提供了决策依据.     

Process conditions for preparing methanol from cornstalk gas

The low-heat-value cornstalk gas produced in the down-flow fixed bed gasifier was tentatively used for methanol synthesis. The cornstalk gas was purified and the technical procedures such as deoxygenation, desulfurization, catalytic cracking of tar, purification and hydrogenation were studied. The catalytic experiments of methanol synthesis with cornstalk syngas were carried out in a tubular-flow integral and isothermal reactor. The effect of reaction temperature, pressure, catalyst types, catalyst particle size, syngas flow at entering end and composition of syngas was investigated. The optimum process conditions and yield of methanol from cornstalk syngas were obtained. The experimental results indicated that the proper catalyst for the synthetic reaction was C301 and the optimum catalyst size was 0.833 mm x 0.351 mm. The optimum operating temperature and pressure were found to be 235癈 and 5 MPa, respectively. The suitable syngas flow 0.9-1.10 mol/h at entering end was selected and the best composition of syngas were CO 10.49%, CO2 8.8%, N2 37.32%, CnHm 0.95% and H2 40.49%. The best methanol yield was 0.418 g/g cornstalk. This study provided the technical support for the industrial test of methanol production from biomass (cornstalk) gas.     

失活甲醇催化剂用于脱除硫化氢的研究

本文研究了失活甲醇催化剂用于脱除硫化氢的试验。结果表明,失活甲醇催化剂具有较好的脱硫性能,其重量硫容在室温和６２３Ｋ时稍低于工业氧化锌脱硫剂,在４２３Ｋ－５２３Ｋ的温度范围内则大于工业氧化锌脱硫剂,其体积硫容在室温下大于工业氧化锌脱硫剂,失活甲醇催化剂的工作硫容随着的升高而增长,而且在低反应空速时或者经过还原后具有更大的硫容。     

σ-AgFeO2晶相对银铁复合氧化催化剂表面氧性能的影响

采用共沉淀法制备了一系列不同摩尔比的银铁复合氧化物催化剂。采用ＸＲＤ,ＴＰＤ－ＭＳ,ＴＰＲ等技术以及ＣＯ氧化反应考察银了铁复合氧化物催化剂的结构和表面氧性质。