Hausmann Angela, Sanciolo Peter, Vasiljevic Todor, Kulozik Ulrich, Duke Mikel
Institute for Sustainability and Innovation, College of Engineering and Science, and.
Advanced Food Systems Research Unit, College of Health and Biomedicine, Victoria University, PO Box 14428, Melbourne, Victoria, 8001, Australia.
J Dairy Sci. 2014;97(1):56-71. doi: 10.3168/jds.2013-7044. Epub 2013 Nov 21.
Membrane distillation is an emerging membrane process based on evaporation of a volatile solvent. One of its often stated advantages is the low flux sensitivity toward concentration of the processed fluid, in contrast to reverse osmosis. In the present paper, we looked at 2 high-solids applications of the dairy industry: skim milk and whey. Performance was assessed under various hydrodynamic conditions to investigate the feasibility of fouling mitigation by changing the operating parameters and to compare performance to widespread membrane filtration processes. Whereas filtration processes are hydraulic pressure driven, membrane distillation uses vapor pressure from heat to drive separation and, therefore, operating parameters have a different bearing on the process. Experimental and calculated results identified factors influencing heat and mass transfer under various operating conditions using polytetrafluoroethylene flat-sheet membranes. Linear velocity was found to influence performance during skim milk processing but not during whey processing. Lower feed and higher permeate temperature was found to reduce fouling in the processing of both dairy solutions. Concentration of skim milk and whey by membrane distillation has potential, as it showed high rejection (>99%) of all dairy components and can operate using low electrical energy and pressures (<10 kPa). At higher cross-flow velocities (around 0.141 m/s), fluxes were comparable to those found with reverse osmosis, achieving a sustainable flux of approximately 12 kg/h·m(2) for skim milk of 20% dry matter concentration and approximately 20 kg/h·m(2) after 18 h of operation with whey at 20% dry matter concentration.
膜蒸馏是一种基于挥发性溶剂蒸发的新兴膜过程。与反渗透相比，其一个常被提及的优点是通量对处理流体浓度的敏感性较低。在本文中，我们研究了乳制品行业的两种高固形物应用：脱脂乳和乳清。在各种流体动力学条件下评估了性能，以研究通过改变操作参数减轻污垢的可行性，并将性能与广泛应用的膜过滤过程进行比较。过滤过程是由液压驱动的，而膜蒸馏利用热量产生的蒸汽压来驱动分离，因此操作参数对该过程有不同的影响。使用聚四氟乙烯平板膜，通过实验和计算结果确定了在各种操作条件下影响传热和传质的因素。发现线速度在脱脂乳处理过程中会影响性能，但在乳清处理过程中不会。发现较低的进料温度和较高的渗透物温度可减少两种乳制品溶液处理过程中的污垢。通过膜蒸馏浓缩脱脂乳和乳清具有潜力，因为它对所有乳制品成分的截留率都很高（>99%），并且可以在低电能和低压（<10 kPa）下运行。在较高的错流速度（约0.141 m/s）下，通量与反渗透相当，对于干物质浓度为20%的脱脂乳，可持续通量约为12 kg/h·m²，对于干物质浓度为20%的乳清，运行18小时后通量约为20 kg/h·m²。
