Direct Contact Membrane Distillation of Dairy Process Streams

Abstract

Membrane distillation (MD) was applied for the concentration of a range of dairy streams, such as whole milk, skim milk and whey. MD of a pure lactose solution was also investigated. Direct contact MD (DCMD) mode experiments were carried out in continuous concentration mode, keeping the warm feed/retentate and cold permeate stream temperatures at 54 °C and 5 °C respectively. Performance in terms of flux and retention was assessed. The flux was found to decrease with an increase of dry-matter concentration in the feed. Retention of dissolved solids was found to be close to 100% and independent of the dry-matter concentration in the feed. Fourier Transform Infrared Spectroscopy (FTIR) of the fouled membranes confirms organics being present in the fouling layer.

Principles of Membrane Filtration

“…40-80 • C) and, thus, allows waste heat and solar energy to be used to drive the process. The origin of MD lies in desalination, and it has also been tested for concentration purposes in the food industry, like fruit juices and different dairy streams (Gunko et al ., 2006;Kozák et al ., 2009;Hausmann et al ., 2011). There are different ways to condense the permeating vapour on the cold side of the process (Fig.…”

Economic analysis of desalination technologies in the context of carbon pricing, and opportunities for membrane distillation

“…Research intensity picked up in the 1980's [5] due to rising water, energy and environmental issues. We have previously explored polymer and ceramic membranes for desalination, and explored MD in dairy processing and industrial process integration [24][25][26][27][28]. While MD researchers have already focussed on relative technology costs, process optimisation, module design and fouling, this paper presents results on a niche operation of extended RO recovery, as well as the relative price of MD under a carbon tax and in a modified operational mode.…”

Advances in Membrane Distillation for Water Desalination and Purification Applications

“…With fouling/performance design, fundamental understandings of the diffusion mechanisms coupled with heat and mass transfer has unlocked the critical science needed to select optimal operating conditions, membrane materials and module designs that ultimately give better flux performance for the same operational conditions [52,53,127]. Fouling of membranes has explored scaling issues for the classic applications in brine concentration [72,128], and the more novel application in dairy processing [129]. While this research progresses to uncover further fundamental improvements, the focus here is on the novel process configurations that address the performance limitations defined in Section 2.1.…”

“…In dairy applications, evaporating whey and skim milk can be done with MD at milder temperatures [129,210]. Recently a study was conducted in Australia to concentrate whole milk, skim milk, whey and a pure lactose solution using DCMD with PTFE flat sheet membranes [129]. The purpose of the study was to evaluate the performance of the process for improving the sustainability of dairy processing from milk down to pure lactose.…”