Nanofiltration Membrane Concentration Technology for Energy-Saving and High-Purity Dairy Processing Abstract

With the rapid growth of demand for high-quality dairy products such as high-protein milk, functional whey powder, and low-salt dairy raw materials worldwide, dairy manufacturers have put forward higher requirements for processing accuracy, nutrient retention, and energy consumption control. Traditional dairy concentration and purification methods have obvious technical limitations. Thermal evaporation processes consume massive energy and easily cause denaturation of milk protein and loss of active substances. Single ultrafiltration technology can only intercept macromolecular proteins but cannot remove excess lactose and soluble salts in dairy raw liquid, resulting in high salt content, poor taste, and low added value of finished products. These bottlenecks restrict the production of high-end customized dairy ingredients. In this context, nanofiltration (NF) membrane technology has become a key innovative technology for iterative upgrading of dairy processing lines with its dual advantages of selective concentration and precise desalination.

Nanofiltration membrane separation technology is a intermediate membrane separation process between ultrafiltration and reverse osmosis, with a unique molecular weight interception range and charge selectivity. Different from other membrane technologies, nanofiltration membranes can effectively intercept macromolecular substances such as milk protein, whey protein, and polysaccharides, while allowing partial penetration of divalent salts and small molecular organic substances, and efficiently removing excess monovalent salts, free lactose, and tiny impurities in dairy raw liquid. The entire concentration and purification process is completed at room temperature and low pressure without heating and phase change. It avoids protein denaturation and nutrient loss caused by high-temperature treatment, and solves the pain points of high salt residue, poor product purity, and single processing function of traditional dairy separation equipment.

Our factory independently designs and manufactures industrial nanofiltration membrane systems for professional dairy processing, which are widely used in whey liquid concentration and desalination, raw milk standardization, dairy wastewater resource recovery, and functional dairy ingredient refinement. The integrated skid-mounted system adopts food-grade sanitary design, equipped with high-flux anti-fouling nanofiltration membrane modules, stainless steel fully enclosed pipelines, intelligent constant-pressure control units, variable-frequency speed regulation feeding systems, and full-automatic CIP cleaning and sterilization devices. The equipment meets international food safety and GMP production standards, realizing continuous, stable, and sterile industrial operation. Through optimized cross-flow filtration technology, the system effectively alleviates membrane fouling caused by dairy protein and fat deposition, maintaining long-term high-flux operation and reducing equipment maintenance costs.

Compared with traditional thermal evaporation and single ultrafiltration processes, nanofiltration membrane systems have unparalleled comprehensive advantages in dairy industrial production. Firstly, the low-temperature and low-pressure operation mode completely preserves the natural activity and nutritional characteristics of milk and whey proteins, ensuring the pure flavor and stable quality of finished dairy products. Secondly, the unique selective desalination function of nanofiltration accurately reduces excess soluble salts in dairy raw materials, significantly improving the taste and quality of whey powder, milk base materials, and infant formula auxiliary materials. In terms of energy consumption, nanofiltration concentration saves more than 35% of operating energy compared with traditional evaporation concentration, greatly reducing the carbon emission and production cost of dairy factories.

In the core production of whey protein series products, nanofiltration technology serves as an essential post-treatment process for ultrafiltration whey liquid. After ultrafiltration intercepts whey protein, the nanofiltration system further concentrates the whey raw liquid and removes residual lactose and inorganic salts, effectively improving the protein content and purity of finished WPC and WPI products. The adjustable filtration precision and concentration ratio can meet the production requirements of low-salt whey powder, high-purity whey protein and other high-end dairy raw materials, which are widely used in infant formula, sports nutrition food and health product manufacturing. In raw milk processing, nanofiltration technology can standardize milk components, balance protein and dry matter content, and improve the batch consistency of commercial dairy products.

The standard industrial processing flow of dairy nanofiltration membrane system includes raw liquid pretreatment, precision security filtration, constant-pressure nanofiltration circulation concentration, desalination purification, concentrated material collection, permeate water recovery and automatic cycle cleaning. The pretreated dairy raw liquid is transported to the nanofiltration membrane module through a sterile delivery system. Under stable pressure driving, effective nutrient components are intercepted and concentrated, while excess salts and small-molecule impurities are discharged with the permeate liquid. After reaching the preset concentration and purity standards, the high-purity dairy concentrated liquid is automatically collected. After the production is completed, the intelligent CIP system automatically cleans and sterilizes the membrane elements and pipelines to eliminate material residue, restore membrane flux, and ensure the stability of long-term continuous production.

With the global dairy industry moving toward green low-carbon, intelligent and high-value development, dairy nanofiltration membrane concentration technology has become an important technical support for dairy enterprises to optimize production processes, reduce energy consumption and upgrade product quality. It makes up for the functional defects of traditional dairy separation and concentration equipment, and has outstanding application prospects in high-end dairy ingredient production and clean dairy manufacturing.

Our company provides customized nanofiltration membrane separation solutions for dairy production. According to different raw material properties, production capacity, and finished product index requirements, we design personalized membrane system configurations and complete production line schemes for customers. We provide one-stop full-cycle services including equipment manufacturing, on-site installation and commissioning, and process parameter optimization, helping global dairy manufacturers improve raw material utilization, reduce production costs, and create high-value dairy products for the international market。