Application of reverse osmosis membrane in food processing a
The application of reverse osmosis in food processing and bioengineering includes 4 aspects: process water treatment, product effective component recovery, dehydration and concentration, and material separation. The selection of membrane method is determined by the inherent advantages of the technology process of food and biological product concentration, separation and recovery, such as reverse osmosis can be operated in a closed loop under normal temperature, thereby reducing the thermal degradation of oxygen in the air of the liquid and evaporation process; reverse osmosis operation is pressurized conveying process, simple process, no solvent phase, greatly saves energy; especially in the added value of dilute trace components solution of high concentration, recovery, other methods have many difficulties, and reverse osmosis is feasible.
Milk protein, amino acids and polysaccharide separation and concentration is the main application of reverse osmosis technology in this field, the use of reverse osmosis (directly or indirectly to permeate ultrafiltration after treatment of milk and whey) is very popular in Europe and the United States, a set of 7000m2 membrane area (tube type main) reverse osmosis process about $60 million of other applications including recovery in food processing of sugar, acid and alkali and other food processing chemicals, fruit juice (Tomato Juice, Orange Juice, Apple Juice, Grape Juice etc.) concentration, separation of polysaccharide and protein, extraction of active ingredients of Chinese medicine, aromatic substances and recovery in the fermentation of alcohol water separation so, many of them have industrial application.
The key to the application of membrane technology in food processing and biological products is to solve the problem of membrane fouling in use, which is usually solved through membrane module design, process matching and cleaning. It is worth noting that the application of membrane separation often require the salt rejection rate is low, and the complete interception of organic matter, such as sugar, amino acid and salt and salt dyes and the proper separation of the separation, this time, nanofiltration is a promising technology, which is developed in recent years by nanofiltration membrane the key to become one of the reasons. Generally speaking, in the process of application by reverse osmosis or nanofiltration technology a unit to solve all the problems the idea is not realistic, the combination process is often the most effective way of industrialization, such as reverse osmosis nanofiltration and electrodialysis, thin film evaporation, crystallization, evaporation and infiltration to promote the rational combination of transfer etc. the.
Reverse osmosis / nanofiltration (NF) technology has become one of the leading technologies in modern industry. Although the production of films in the world many manufacturers and research units, but the status quo is the top four or five major multinational companies have production and market more than 90% of the world, and in 1998 the whole world is the reverse osmosis membrane market sales reached US $200 million (the film plan), the development prospects are very bright. This can be clearly seen from seawater and brackish water desalination and pure water and ultra pure water production market is still very strong, wastewater treatment and bioengineering applications gradually spread. It is the main task and goal of scientists and engineers in this century to develop and develop more economical membrane products, which are highly resistant to oxidation, pollution and selectivity, and can be widely applied to water supply and wastewater treatment systems.