Key aspects of membrane plant operations related to fouling and cleaning in the food industry

Fouling is one the most important challenges to apply membrane technology on industrial scale in the food industry. Despite significant progress in understanding and preventing fouling and in developing appropriate membrane cleaning protocols, both fouling and cleaning remain key challenges in membrane plant operation in the food industry with a significant impact on membrane plants capital (CAPEX) and operating expenditures (OPEX) and thus the sustainability of membrane processes. The goal of this presentation is to show a relationship between fouling, pre-treatment, operation conditions and cleaning and how this can impact industrial membrane processes from a techno-economical point of view.

The first part of the presentation will analyze the state-of-the-art of membrane cleaning in the food industry. The impact of e.g. number of cleaning cycle per day, cleaning cycle length and cleaning chemicals as well as type of cleaning chemicals and water quality will be discussed with regard to their impact on membrane plant OPEX and CAPEX.

In the subsequent part of the presentation different approaches to reduce fouling and minimize the need for cleaning will be highlighted. The focus will be on the impact of pre-treatment but also on membrane module and membrane selection.

The final part of the presentation will be an application study related to the removal of impurities e.g. retrograded starch, proteins and fat in the production of starch-based sweetener after liquefaction and saccharification of the starch. For this production step - which is often referred to as demudding - a new concept has been developed consisting of a decanter and membranes. The application study will demonstrate how the membrane part of the process was adjusted to overcome some serious fouling and thus capacity challenges encountered during the start-up of the first installation. The resulting new concept did not only control the fouling and minimized the cleaning but it also resulted in an improved sweetener quality.

Overall the presentation will show approaches to reduce fouling and cleaning in order to support the long-term sustainability of membrane processes in the food industry.