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KEY BENEFITS OF NANOFILTRATION TECHNOLOGY Nanofiltration is a membrane process situated between R.O. and Ultrafiltration. It is a process that rejects based on molecular weight, shape of the molecule and charge (i.e. the membrane will allow the passage of sodium and chloride through the membrane, but will reject magnesium and sulphate ions). Nanofiltration IS NOT "loose R.O." as has been stated in the media rececntly! NF will reject between 0-50% of sodium chloride depending on operating conditions, whereas "loose RO" is a membrane with reduced salt rejection. A true NF membrane will allow complete passage of monovalent ions, whereas "loose RO" will have reduced monovalent ion rejection, but will show rejection. Based on tests using both membrane processes, RO will reject approximately 50% of the ethanol in the wine, whereas NF will allow almost complete passage of ethanol through the membrane allowing for a much lower operating pressure. Developed in South Africa and marketed by VA Filtration, the main benefit of our nanofiltration/adsorption process is that the wine is not subjected to pressures greater than 250 psi. In fact, the process operates at pressures of around 17 bar (250 psi) depending on the temperature, cleanliness and residual sugar level of the wine. This negates the need for a heat exchanger in order to keep the wine cool while processing. The VA process involves the use of nanofiltration (combination of molecular weight and charge based rejection) in combination with acid adsorption on the permeate. The acid adsorption process only targets the acetic acid and does not remove the ethyl acetate. We are able to achieve this by running our permeate stream at a pH of between 7 and 10 using specially selected resin based on years of testing. The results are: a minimum 30% removal of the volatile acidity (acetic acid) on a single pass through the process. This system is also capable of removing Brettanomyces compounds 4EP/4EG from the wine as well as ethanol using a separate second stage removal process.
View of the machine currently operating in the field!
TECHNICAL PROCESS DESCRIPTION Wine is drawn from on-site storage tanks at a rate of 1800 l/hr (480 gal/hr) indicated as Stream 1. The wine is fed to a diaphragm pump, which uses diaphragms to pressurize the wine to approximately 17 bar, preventing turbulence and mechanical stresses to the wine itself. Following pressurization, the wine is piped to the nanofiltration process (Stream 2), where the flavor and aroma compounds (Stream 3) are separated from the water, alcohol and acetic acid (Stream 4). This molecular filtration process uses a nanofiltration membrane to separate these large molecular weight organic compounds from the smaller molecular weight compounds. The result is two streams of differing composition each flowing at 900 l/hr (240 gal/hr). Stream 3 is piped separately for re-combination with a processed Stream 4 at a later stage. Stream 4 is now fed to an adsorption process for further processing. Using adsorption technology, the acetic acid is selectively removed from Stream 4. The result is a stream containing only water and alcohol (Stream 5). The processed Stream 5 is re-combined with Stream 3 resulting in wine with lower volatile acidity and piped to a processed wine storage tank. The entire process is extremely gentle on the wine.
Key Benefits of our systems!
BRETT REMOVAL INCLUDING 4EP AND 4EG REDUCTION The same VA reduction equipment can be used for the removal of 4EP from the wine. PricingThere are several models of machines available for purchase. Please contact us for your requirements. For service pricing please follow the link to our service page and contact the relevant sales person in your country.
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