Efficient Low-temperature Hydrogen Production by Electrochemical-assisted Methanol Steam Reforming

Methanol steam reforming (MSR) provides an alternative way for efficient production and safe transportation of hydrogen but requires harsh conditions and complicated purification processes. In this work, an efficient electrochemical-assisted MSR reaction for pure H₂ production at lower temperature (~140 °C) is developed by coupling the electrocatalysis reaction into the MSR in a polymer electrolyte membrane electrolysis reactor. By electrochemically assisted, the two critical steps including the methanol dehydrogenation and water-gas shift reaction are accelerated, which is attributed to decreasing the methanol dehydrogenation energy and promoting the dissociation of H₂O to OH* by the applied potential. Furthermore, the reduced H₂ partial pressure by the hydrogen oxidation and reduction process further promotes MSR. The combination of these advantages not only efficiently decreases the MSR temperature but also achieves the high rate of hydrogen production of 505 mmol H₂ g _Pt⁻¹ h⁻¹ with exceptionally high H₂ selectivity (99 %) at 180 °C and a low voltage (0.4 V), and the productivity is about 30-fold than that of traditional MSR. This study opens up a new avenue to design novel electrolysis cells for hydrogen production.     

基于局域操作下的两量子比特混态纠缠蒸馏实验研究

最大纠缠态在量子信息传输和处理过程中是最重要的资源之一,因此从退化的纠缠态中提炼出最大纠缠态一直是量子信息基础研究中的一个重要课题.根据Verstraete F 等人在Phys. Rev. A,2001,64：010101(R) 上提出的有效的方法,文章作者在实验上证明了基于局域操作下的两种形式的两量子比特混态纠缠蒸馏最佳协议.从原则上讲,文章的实验也可以容易地应用于任意两量子比特部分混合态的纠缠蒸馏.此外,作者还对经过蒸馏的第一类混合量子态进行Clauser-Horne-Shimmony-Holt（CHSH）不等式的检测,以验证它的“隐藏非局域性”.     

氯化锂为添加剂制得的疏水聚偏氟乙烯不对称微孔膜的形态结构及其膜蒸馏性能

结合膜的形态结构研究了以 LiCl为添加剂制得的疏水 PVDF膜的膜蒸馏性能。与来用水溶液高分子添加剂制得的PVDF微孔膜相比,膜蒸馏性能有了较大提高,尤其具有更高的截留率。制得的微孔膜的蒸馏通量已接近商品膜的膜蒸馏通量,表明以LiCl为添加剂制得的PVDF疏水微孔膜是一种适用于膜蒸馏的较理想的疏水微孔膜。     

ZrO2在Cu-ZnO-ZrO2甲醇水蒸汽重整制氢催化剂中的作用

通过对一系列Cu-ZnO-ZrO2甲醇水蒸汽重整(SRM)催化剂的XRD、TEM和BET表征及催化性能测定,研究催化剂中ZrO2对催化剂粒径、比表面以及对SRM反应性能的影响.结果表明,ZrO2的加入,使催化剂的粒径从15 nm降至10 nm（其中CuO和ZnO的平均粒径分别从7.7和10.4 nm降至3.9和8.7 nm）,BET比表面从60 m2•g－1增至78 m2•g－1.随着催化剂含ZrO2量不同,甲醇的转化率和H2、CO2的选择性均产生变化,当催化剂中Zr含量为24.0％(w),反应温度为220 ℃,水、醇摩尔比为1.3时,甲醇的转化率达到51.6％, H2和CO2的选择性达到100％(CO和CH4在产物气体中的体积分数小于10－4),这一结果对甲醇燃料电池甲醇重整器的应用具有重要的意义.     

甲醇生产主精馏塔的模拟计算

对甲醇精馏主塔进行了模拟计算，并以一实际生产装置沿塔身的温度与浓度分布进行了验证。结果表明，水和甲醇的平均偏差为０．９％，微量杂质，不计丁基油，平均偏差为４９ｐｐｍ，温度平均偏差为２．９℃。说明本计算方法及采用的模型参数是可靠的，可用于工程计算。本文进一步指出，为降低废水中醇类含量，较理想的方法是选择合适的精甲醇与丁基油的采出量。     

合成乳酸乙酯精馏残液的分析

合成乳酸乙酯精馏残液的分析张青枝，华国雄，鲁富贵，张深松，赵根锁（河南师范大学化学系新乡４５３００２）（河南省化学研究所郑州）关键词乳酸乙酯，精馏残液，红外光谱，电子轰击质谱采用乳酸、乙醇直接酯化法［１］，有机溶剂共沸法［２］，合成乳酸乙酯收率较低。...     

Synthesis of distillation trains with heat integration by a combined fuzzy and graphical approach

After passing some results of fuzzy synthesis of heat exchanger networks in review the application of this approach to the synthesis of distillation trains for the separation of multicomponent mixtures is demonstrated. The available heuristic rules are transformed into fuzzy implications dependent on different criteria and that competing rule, which is to be applied, is selected by the fuzzy algorithm.The theoretically possible amount of heat recovery within the networks generated in this way is estimated by a graphical method and included in the final cost evaluation. Regarding operating parameters like column pressure and reflux ratio, according to the mathematical effort at least qualitative statements can be made in result of the estimation of possible heat recovery.As already in the case of heat exchanger networks a following learning algorithm can serve to overcome the disadvantages of this sequential approach, representing at the same time the first step of a further evolutionary improvement of the initial distillation train.     

Optimization of distilled monoglycerides production

Monoglycerides (MG) are emulsifiers widely used in food and pharmaceutical industries. Current industrial processes for MG production consist of the interesterification of triglycerides with glycerol (GL), in the presence of inorganic catalysts at high temperatures (>200°C). This reaction is known as glycerolysis and produces a mixture of approx 50% of MG. This level of concentration is suitable for many applications, although, for some specific uses like margarine, shortening, icing, and cream filling, require distilled MGs, which are purified MG (min. 90%) obtained by the molecular distillation process. Therefore, in this work, a 2³ factorial design was employed to evaluate the effects of reaction parameters in the MG content after the interesterification reaction of refined soybean oil with GL in the presence of sodium hydroxide as catalyst. After that, the MG content in the reaction product was enhanced through the molecular distillation process in order to obtain distilled MG.     

Comparison of two turbulent models in simulating evaporating liquid film in a wiped molecular distillator

Wiped molecular distillation is one kind of molecu-lar distillations, and its difference from others comes from the force by which the evaporating liquid film is formed. With quick rotation of the wiper, the liquid becomes thin-film well distributed on th…