Feasibility analysis of membrane reactors – discovery of reactive arheotropes

A feasibility analysis methodology adopted from reactive distillation is applied to membrane reactors. A model is formulated to depict the reactive liquid phase composition on the retentate side of a continuous type membrane reactor. The effects of both the chemical reaction kinetics and the membrane mass transfer kinetics on the feasible products are elucidated by means of retentate phase diagrams and bifurcation analysis. The proposed method can be applied to various membrane processes, independent of the specific structure of the membrane. Two quaternary reaction systems are considered to illustrate the methodology. In the first hypothetical system, it is shown how selective membranes can influence the sequence of effective volatilities which in turn affects the feasible products of the system. In the second example of practical importance, i.e. the heterogeneously catalysed synthesis of propyl acetate coupled with permeation through a porous polycarbonate membrane, the dusty gas model is applied to describe the component fluxes through the membrane. For the latter reaction system, the existence of reactive arheotrope is demonstrated. Arheotropes represent mass transfer controlled feasible products of membrane separation process.     

Degradation of polymer electrolyte membranes

One of the predominant failure modes of polymer electrolyte membrane (PEM) fuel cells is the degradation of the PEM, especially when the fuel cell is used for transportation applications. Numerous studies have been carried out regarding this issue but many aspects of the degradation are not yet understood. This paper reviews the available literature regarding membrane degradation, and attempts to classify the degradation modes into three categories: mechanical, thermal and chemical/electrochemical. The factors that contribute to each mode are discussed, along with detailed mechanisms for some degradations. Some possible mitigation strategies are also explored.     

Metabolic P Systems： A Discrete Model for Biological Dynamics

A recent methodology to model biochem- ical systems is here presented. It is based on a concep- tual framework rooted in membrane computing and de- veloped with concepts typical of discrete dynamical sys- tems. According to our approach, from data observed at suitable macroscopic temporal scales, one can deduce, by means of algebraic and algorithmic procedures, a dis- crete model （called Metabolic P system） which accounts for the experimental data, and opens the possibility to under- stand the systemic logic of the investigated phenomenon. The procedures of such a method have been implemented within a computational platform, a Java software called MetaPlab, processing data and simulating behaviors of metabolic models. In the paper, we briefly describe the theory underlying the modeling of biochemical systems by Metabolic P systems, along with its development stages and the related extensive literature.     

小麦淀粉加工工业废水处理研究进展

小麦淀粉加工工业产生大量的高浓度有机废水，直接排放对环境造成极大的污染。文中介绍了此废水的产生逢径．对此废水进行处理的必要性和意艾；详细介绍了谊废水处理方法的研究进展，如生物法、蒸发法、化学絮凝法等．总鲒了这些方法的不足之处，提出了将膜技术用于此领域的巨大潜力。     

膜分离技术提取大豆乳清中的低聚糖

利用膜分离技术提取大豆乳清中的低聚糖,重点研究了反渗透操作条件,讨论了加热乳清以及膜情况的工艺步骤     

酶膜分离法果汁澄清工艺

运用果胶酶，淀粉酶等澄清剂，结合膜分离技术，分析得出适合沙棘，柠檬汁，梨汁，猕猴桃汁，葡萄汁，梨汁，猕猴桃汁，葡萄汁，山渣汁，枣汁等果汁的澄清工艺。能有效去除果汁饮料中的果胶，蛋白和高级棕榈酸酯絮状物等造成沉淀的物质。     

国际乳业的热点论题：蛋白质标准化

介绍了蛋白质的标准化这一国际乳品界正热的研究和讨论题目，综述了蛋白质标准化的必要性和世界上目前采用的方法，展望了膜技术在蛋白质标准化上的应用前景。     

Comparisons between membranes for use in cross flow membrane emulsification

Emulsification is an important process, particularly in food production. Membrane emulsification attempts to improve on traditional emulsification methods by producing each droplet singly. Cross flow membrane emulsification uses the flow of the continuous phase to detach droplets from the membrane pores. Different factors were investigated, including the effects of cross flow velocity, trans-membrane pressure, and emulsifier concentration. The effects of using different membrane materials and morphologies were directly compared. The trans-membrane pressure was found to have a large effect on the diameter (D[4,3]) of the droplets, with similar results for all the studied membrane types. Increasing the pressure increases droplet sizes, and can be related to the different mechanisms of droplet detachment from the membrane. An increase in the linear cross flow velocity was shown to cause a decrease in the diameter of the produced droplets. The different membranes each have different characteristics.     

膜浓缩技术与真空冷冻干燥在茶饮料中的应用

膜浓缩与真空冷冻干燥应用于茶饮料工业中，与传统工艺方法比较，解决了茶饮料中冷后浑，混浊等缺陷。