Membrane‐Freeze Concentration Hybrid for Temperature‐Sensitive Biomolecules. Investigation, Application, and Techno‐Economic Benefits

Abstract

In order to close the technology gap between membrane technologies and spray/freeze‐drying ideally with a technology that avoids thermal stress to sensitive enzyme solutions, the limits of freeze concentration for this application have been investigated. On laboratory scale it was found that average crystal sizes are > 300 µm despite high viscosity and ice separation is possible up to 42 % solids and > 1000 mm2s−1 viscosity. No activity loss was observed during concentration. A combination of two‐stage freeze concentration with a filter and wash column for ice liquid separation in an integrated setup with ultrafiltration has the greatest potential and was shown to be economically feasible in three out of four cases studied.

Effects of Centrifugal Block Freeze Crystallization on Quality Properties in Pineapple Juice

“…The differences in final solute concentration and/or process parameters terms can be explained by the ice front propagation for each FC technology . BFC presented a better final concentration and lower solute retention in C i than PFC due to a phenomenon called constitutional supercooling, i.e., the ice growth rate depends on the cooling temperature and the heat transfer area, which is an important factor in the design of FC equipment .…”

“…This inverse effect could be attributed to the soluble content (°Bx) of the concentrated samples (≈ 32 °Bx), which in turn increased the organic acid content in the juice. A similar phenomenon was reported by Bonilla‐Zavaleta et al and Khajehei et al for pineapple juice and pomegranate juice, respectively. The density of the samples increased as the TSSC became higher at each cycle.…”

Sustainable nutrient recovery from animal manure: A review of current best practice technology and the potential for freeze concentration

“…Membrane technologies target treating those effluents containing compounds or elements that may be either retained or pass through a thin physical barrier depending on molecular or particle size, concentration of certain compounds, operational temperature and applied pressure (Logan and Visvanathan, 2019;Van-Beek et al, 2018). Many parameters should be considered to apply membrane filtration such as the chemical composition of the effluent to be treated and the interactions between membrane surface and components in the feed flow (Logan and Visvanathan, 2019).…”

“…The maximum concentration obtainable is determined by the viscosity of the concentrate and the freezing point (Ruemekorf, 2000). The maximum concentration is reached when the viscosity of the liquid prevents the growth of ice crystals ( Van-Beek et al, 2018). The crystal growth rate decreases as viscosity increases and the system requires a longer residence time (and thus larger equipment) to reach a separable crystal size because the capacity of ice separator is inversely proportional to the viscosity (Petzold and Aguilera, 2009).…”

“…The effective ice removal and separation can be done in wash columns specifically developed for this purpose. Using this technique the impurity of the ice crystals are <100 ppm ( Van-Beek et al, 2018), which is highly attractive. Although SFC has been used industrially in liquid food applications as a key technology, in practice the Ostwald ripening process needs a long operation time.…”