Sivertsen Edvard, Holt Torleif, Thelin Willy R
SINTEF, Richard Birkelands veg 3, N-7034 Trondheim, Norway.
Membranes (Basel). 2018 Jul 8;8(3):39. doi: 10.3390/membranes8030039.
Osmotic power extracted from the mixing of freshwater with seawater is a renewable energy resource that has gained increasing attention during recent years. The estimated energy can significantly contribute to the production of power worldwide. However, this power production will be subject to variation due to both local conditions and seasonal variation. The present paper explores the effect of concentration and temperature on water and salt fluxes in osmosis at zero transmembrane pressure for five different membranes. Further, the measured fluxes have been utilized to model water and salt permeabilities ( and ), and the structure parameter (). The observed flux variations at different combinations of concentration and temperature have been ascribed to skin properties, i.e., changes in and of each membrane, whereas was assumed constant within the range of concentrations and temperatures that were tested. Simplified equations for the variation in and with temperature and concentration have been developed, which enable and to be calculated at any concentration and temperature based on permeabilities determined from osmotic experiments at standard test conditions. The equations can be used to predict fluxes and specific power production with respect to geographical and seasonal variations in concentration and temperature for river water/seawater pressure-retarded osmosis. The obtained results are also useful for forward osmosis processes using seawater as draw solution.
从淡水与海水混合中提取的渗透能是一种可再生能源，近年来受到了越来越多的关注。据估计，这种能源可为全球电力生产做出重大贡献。然而，由于当地条件和季节变化，这种电力生产将受到影响而产生波动。本文探讨了浓度和温度对五种不同膜在零跨膜压力下渗透过程中水通量和盐通量的影响。此外，利用测量得到的通量对水渗透率、盐渗透率（ ）和结构参数（ ）进行了建模。在不同浓度和温度组合下观察到的通量变化归因于膜表皮特性，即每种膜的 和 的变化，而 在测试的浓度和温度范围内假定为常数。已推导出 和 随温度和浓度变化的简化方程，这使得能够根据在标准测试条件下通过渗透实验确定的渗透率，计算出任何浓度和温度下的 和 。这些方程可用于预测河水/海水压力延迟渗透中浓度和温度的地理及季节变化所对应的通量和特定发电量。所得结果对于以海水作为汲取溶液的正向渗透过程也很有用。
