PROJECT DESCRIPTION
BACKGROUND
the brewery industry generates an estimated 45,000 tonnes of kieselgurh yearly in EU countries; this has created an environmental problem for the industry. No alternatives to kieselguhr are today found and membrane filtration is seen as an attractive technical and economical alternative that requires no filter aid. Thereby waste problems and any potential health hazards can be avoided. To achieve this goal two membranes and concepts will be used and applied. The disposal of kieselguhr sludge has become increasingly difficult in recent years and the focus on health risks in relation to kieselguhr, which is a carcinogenic to humans when inhaled, has increased. Furthermore, the main way to dispose of used kieselguhr sludge is by disposal at landfills. As environmental rules become stricter, it can be expected that kieselguhr usage will get more expensive and some countries have considered banning the use of the product altogether. Membrane filtration is a pressure driven process utilising an ultra thin membrane to concentrate and/or separate different sizes of components in a liquid solution. A basic membrane filtration plant consists among others of a circulation pump that creates the flow necessary to remove a potential fouling of the membranes. This is, however, only reasonable for a certain period of time - after several hours of production a fouling layer is created, which reduces the beer flow through the membranes (flux). The production is then interrupted for cleaning. The novel IPN membrane has a semi-crystalline polymer on the surface. It has been developed with a unique Isoporous Interpenetrating Network (IPN) structure combined with poly ether ether ketone and has shown excellent fluxes on laboratory scale. The IPN membrane has to be scaled up to pilot scale. A pilot plant has to be designed, constructed and built, and the process parameters have to be optimised. Furthermore, a ceramic membrane is to be applied with the patented permeate recirculation concept, which is regarded as the best alternative to the IPN membrane. In order to use this concept, a further development in design and construction is necessary for optimising the conditions for beer production.
OBJECTIVES
The objective of this project was to do away with kieselguhr in mainstream beer filtration by replacing the traditional dead end filtration with cross-flow membrane filtration. Kieselguhr is known to cause environmental problems and is also classified as a carcinogenic to humans when inhaled. The replacement of kieselguhr filtration with a more environmentally sound and health caring system has a great deal of attention from the brewing industry.
RESULTS
The ceramic membranes have been tested and the conclusion is that it is possible to use ceramic membranes for clarification of beer by means of cross-flow filtration. The beer quality was as good as or superior to the kieselguhr-filtered beer. The only obstacle is the relatively high costs connected to such a system. The other membranes to be tested were expected to reduce the costs substantially. The IPN polymeric membrane performed with higher filtration rate (flux) as the ceramic membrane (reference), and with lower energy consumption during operation. This makes this membrane very promising. The second alternative membrane that was tested during the project due to substantial delays of the IPN membrane, also showed promising results. However the membrane supplier pulled out of the project due to resource issues. The IPN polymeric membrane was not developed into a final commercial product at the end of the project, but results were quite encouraging and further development of applications of this membrane are likely to proceed. A fully operational IPN membrane is expected to reduce the energy requirement considerably. The ceramic membranes have been tested and the conclusion is that it is possible to use ceramic membranes for clarification of beer by means of cross-flow filtration. The beer quality was as good as or superior to the kieselguhr-filtered beer. The only obstacle is the relatively high costs connected to such a system. The other membranes to be tested were expected to reduce the costs substantially. The IPN polymeric membrane performed with higher filtration rate (flux) as the ceramic membrane (reference), and with lower energy consumption during operation. This makes this membrane very promising. The second alternative membrane that was tested during the project due to substantial delays of the IPN membrane, also showed promising results. However the membrane supplier pulled out of the project due to resource issues. The IPN polymeric membrane was not developed into a final commercial product at the end of the project, but results were quite encouraging and further development of applications of this membrane are likely to proceed. A fully operational IPN membrane is expected to reduce the energy requirement considerably.
