Towards high resolution membrane‐based pharmaceutical separations

Abstract

BACKGROUND In this work the possibility of using membrane cascades to carry out difficult pharmaceutical separations was explored. The effect of configuration on process yield, time and cost was studied for a challenging industrial separation: the separation of an intermediate I (MW 221 g mol−1) from an impurity, ethylene bromide (MW 188 g mol−1). RESULTS All cascade configurations studied were capable of increasing the purity from a fairly low value, namely 26% to the 90% requirement. The results from the cascade modeling showed that the product yield effectively increased from 35.5% to 84.3% by adding two stages. From a cost analysis of a kilo scale plant it was derived that a two‐stage cascade with large area modules yielded the smallest total cost of € 515 082. A 7.0% decrease in cost of product loss or a 7.6% increase in membrane skid cost rendered a single stage economically optimal despite the low product yields. However, if at least six other separations with a comparable process time are carried out each year, then even three stages become economically optimal. CONCLUSION High resolution separations are technically feasible with membrane cascades. The economic viability of membrane cascades increases dramatically with the cost of the product and the utilization of the equipment. Copyright © 2012 Society of Chemical Industry

Solvent recycle with imperfect membranes: A semi-continuous workaround for diafiltration

“…Membrane cascades offer potentially large gains in selectivity and they were developed, often on a purely theoretical basis [15][16][17] although partially experimental [18][19][20][21][22][23] and fully experimentally validated examples exist [4,12,[24][25][26][27]. Much of the published work extrapolates single-stage screening results to predict and analyse the performance of multiple stages.…”

“…Whilst the predictive capability for two-or three-stage cascades may actually be sufficient to warrant the conclusions drawn, there are major obstacles to industrial implementation. Beside the diminishing economic benefit of introducing additional stages [18], process control is challenging with large cascades due to the step increase in complexity and the larger number of equipment needed. Whilst in many ways considered a temperature-flexible, pressure-driven analogue of distillation, a membrane cascade shares many of the same process control problems.…”

Multi-scale modelling of OSN batch concentration with spiral-wound membrane modules using OSN Designer

“…These studies showed the feasibility of OSN technologies in different industries at laboratory scale with flat sheet membranes or with 1.8"x12" spiral-wound membrane modules. In the literature, only a few studies [Peshev et al, 2011;Vanneste et al, 2013;Sereewatthanawut et al, 2010] proposed mathematical models for prediction of the process performance. In these process models, the mass balance equations were derived based on the assumptions of well-mixed solutions in a feed tank and negligible time consumed for retentate circulation.…”

Analysis and optimization of continuous organic solvent nanofiltration by membrane cascade for pharmaceutical separation

“…Ultrafiltration and nanofiltration are the most frequently used membrane technologies for biotechnological and pharmaceutical purposes. Ultrafiltration is widely used for the separation and fractionation of proteins and other biological molecules and nanofiltration cascades have been implemented for pesticide removal, solvent exchange, solvent recovery, and separation and fractionation of pharmaceutical solutes …”