钯银合金膜反应器中二甲醚水蒸汽重整体系的透氢性能研究

二甲醚(DME)由于其清洁环保特性成为燃料电池电动汽车的理想氢源之一。在200~300℃温度范围,1.0×105~4.0×105Pa的压力范围内,Pd-Ag-Au-Ni合金膜对H2与Ar和N2的分离系数接近无穷大,同时,膜具有较好的透氢稳定性。通过实验研究了膜反应器中Ar、N2、CO、CO2、H2O和DME等气体存在时对钯银合金膜透氢性能的影响。实验结果表明,Ar、N2、DME基本对透氢性能无影响,CO2、CO、H2O存在时,会影响氢气的渗透性。三者当中,CO2的影响最小,混合气中H2O比CO对透氢性能的影响大,这是由于H2O在钯膜表面有更大的竞争吸附作用。本研究结果为更详细地研究二甲醚水蒸气重整制氢过程提供了重要参考依据。     

高性能混凝土抗Cl^-渗透性的研究

通过研究大量的文献，就高性能混凝土耐久性的一方面——抗氯离子渗透性进行研究，从四个方面分析影响混凝土中氯离子扩散的因素，以及国内外评价氯离子渗透的方法，最后提出现有的预防及处理氯离子侵蚀的措施。     

凝胶色谱净化-毛细管气相色谱法测定渔业水体中乐果

建立凝胶色谱净化-毛细管气相色谱法测定养殖水体中乐果的分析方法。三氯甲烷萃取水样,经凝胶渗透色谱(GPC)净化除去脂类、色素等,采用脉冲不分流进样模式气相色谱法分析,外标法定量。方法检测限为0.022μg/L;加标水平为1.00μg/L时,实际样品回收率为82.5%～97.1%。该方法自动化程度高、净化效果好、重现性好、准确灵敏。实际样品检测结果表明,此方法满足复杂水体中乐果残留检测要求。     

Oxy‐fuel combustion for CO2 capture using a CO2‐tolerant oxygen transporting membrane

CO₂ capture via an oxy‐fuel route through the U‐shaped (Pr_0.9La_0.1)₂(Ni_0.74Cu_0.21Ga_0.05)O_4+δ (PLNCG) hollow fiber membrane with 100% CH₄ conversion and 100% CO₂ selectivity for 450 h has been explored for the first time. X‐ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy characterizations of the spent hollow fiber membrane have also been investigated. All these results indicate that PLNCG hollow fiber membrane shows excellent reaction performance and good stability under oxy‐fuel reaction conditions, which will be a potential rounte for reducing CO₂ emissions worldwide. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3856–3862, 2013     

A novel porous‐dense dual‐layer composite membrane reactor with long‐term stability

A porous‐dense dual‐layer composite membrane reactor was proposed. The dual‐layer composite membrane composed of dense 0.5 wt % Nb₂O₅‐doped SrCo_0.8Fe_0.2O_3‐δ (SCFNb) layer and porous Ba_0.3Sr_0.7Fe_0.9Mo_0.1O_3‐δ (BSFM) layer was prepared. The stability of SCFNb membrane reactor was improved significantly by the porous‐dense dual‐layer design philosophy. The porous BSFM surface‐coating layer can effectively reduce the corrosion of the reducing atmosphere to the membrane, whereas the dense SCFNb layer permeated oxygen effectively. Compared with single‐layer dense SCFNb membrane reactor, no degradation of performance was observed in the dual‐layer membrane reactor under partial oxidation of methane during continuously operating for 1500 h at 850°C. At 900°C, oxygen flux of 18.6 mL (STP: Standard Temperature and Pressure) cm^?2 min^?1, hydrogen production of 53.67 mL (STP) cm^?2 min^?1, CH₄ conversion of 99.34% and CO selectivity of about 94% were achieved. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4355–4363, 2013     

Melt processing and characterization of polyvinyl alcohol and polyhydroxyalkanoate multilayer films

Multilayer films for food packaging applications composed of polyvinyl alcohol (PVOH) as the core layer and polyhydroxyalkanoate (PHA) as the outer skin layers were produced by the co‐extrusion process. Rheological properties of PVOH and PHA were performed and analyzed before co‐extruding into a cast film. Analysis of the rheological data indicated the processing temperatures and grades of the PVOH and PHA polymers that would produce similar viscosity and melt flow properties. To improve adhesion of the layers, PHA was grafted with maleic anhydride using a dicumyl peroxide initiator to provide a tie layer material, which improved the peel strength of the PHA and PVOH layers by over 2×. Oxygen transmission rate (OTR) testing showed that the multilayer sample provided an OTR of 27 cc/m²‐day at 0% relative humidity (RH) and rates of 41 and 52 cc/m²‐day at relative humidity values of 60% and 90% RH, respectively. This indicates significant barrier performance enhancement over monolayer PVOH that provided an OTR of 60 cc/m²‐day at 0% RH and 999 cc/m²‐day at 60% RH. Biodegradation testing of the films in the marine environment showed that both the unmodified and maleated PHA polymers displayed high levels of mineralization, whereas the PVOH material did not. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of ethylene and butyl methacrylate-based copolymer by emulsion polymerization

The emulsion copolymerization of ethylene with butyl methacrylate (BMA) was carried out in an aqueous medium at 60 °C under moderate reaction conditions. The polymer system is well controlled with a linear increase in the molecular weight (M_n) versus ethylene feed pressure and narrow molecular weight distributions (>1.36) were observed throughout the copolymerization reaction. The spectroscopic analyses confirm the presence of acrylate functional as well as methylene group in the synthesized poly(ethylene-co-BMA) copolymer. Morphological behavior of poly(ethylene-co-BMA) has been studied using SEM and TEM analyses. Thermal stability of the copolymers was investigated by thermogravimetric analysis and it was observed that the copolymer is stable up to 380 °C. X-ray diffraction analysis confirmed the amorphous behavior of poly(ethylene-co-BMA). Dynamic light scattering measurement confirms the formation of poly(ethylene-co-BMA) nanoparticles. The particle size of copolymer nanoparticles were in the range of 85–108 nm with low polydispersity indexes (>0.2). The viscous and the elastic property of the copolymer were investigated and established that at high temperature elastic behavior predominant over viscous effect. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47994.     

3种测试溶液对搪瓷用钢抗鳞爆性能评价指标的影响

采用3种常见的测试溶液检测了10组搪瓷用钢板的氢渗透性能,并同时采用涂搪实验进行验证。结果显示,测试溶液A适用于试验选定的各种厚度的搪瓷用钢,其检测结果准确率可达100%;而溶液B和溶液C在测试厚度1.5 mm以上的搪瓷用钢板料出现部分误判现象。溶液B若基于有效氢扩散系数D_eff,其准确率为70%,若基于TH值,其准确率仅为50%;而溶液C误判率达30%。     

CO2化学吸收法中再生气的陶瓷膜余热回收特性

在CO₂化学吸收法工艺中,采用富液分流工艺,利用在贫富液换热器前分流的冷富CO₂吸收剂溶液回收再生塔顶排出的热再生气（一般为CO₂和水蒸气混合气）的余热,有助于降低CO₂再生热耗。本文在乙醇胺（MEA）基富液分流化学吸收工艺中,以纳米级多孔亲水陶瓷膜作为分流冷富液和热再生气之间的换热介质,利用水的热质耦合传递强化余热的回收性能。以余热回收通量为指标,探讨了分流的MEA富液流量、温度、质量分数、CO₂负荷和热再生气流量及再生气中水蒸气摩尔分数对陶瓷膜热回收性能的影响,并对比了不同分离层孔径陶瓷膜的余热回收性能。结果显示,陶瓷膜的余热回收性能随MEA富液流量的增加而增加,但却随富液温度的升高而大幅下降。同时,随着气体流量和再生气中水蒸气摩尔分数的增大,热回收通量均会增大。由水传质所引发的对流换热对热回收通量具有促进作用,可占总热回收量的10%左右。由于CMHE-10陶瓷膜的分离层孔径与孔隙率均大于CMHE-4陶瓷膜,因而其水传质通量大于CMHE-4陶瓷膜。但CMHE-10陶瓷膜的有效热导率却低于CMHE-4陶瓷膜,因而热回收过程中其水蒸气的冷凝总量要小,导致其热回收性能低于CMHE-4陶瓷膜。