8 Questions Before Choosing a Dairy Membrane System

When requesting a quotation for a dairy membrane system, many customers first ask:

“How much does it cost to process one ton of material?”

However, without information on feed composition, target products, and operating conditions, it is difficult for equipment suppliers to provide a reliable solution. Even with the same processing capacity, two dairy companies may ultimately require completely different membrane types, membrane areas, and process configurations.

Before selecting a membrane system, it is recommended to first confirm the following eight questions.

1. What Exactly Is the Feed Material?

It is necessary to clarify whether the feed is:

●  Fresh milk;

●  Skimmed milk;

●  Whey;

●  Yogurt or fermented milk;

●  Cheese-related streams;

●  Concentrated milk;

●  Dairy processing by-products.

Different feed materials have different protein, fat, lactose, total solids, and microbial characteristics, which can significantly affect membrane fouling and separation performance.

Simply stating “milk processing” is usually not sufficient for membrane system selection.

2. What Are the Feed Composition and Variation Ranges?

It is recommended to provide:

●  Protein content;

●  Fat content;

●  Lactose and salt content;

●  Total solids;

●  pH value;

●  Temperature;

●  Viscosity;

●  Batch variation range.

Dairy feed characteristics can be affected by season, milk source, and upstream processing conditions. The process design should not only adapt to average operating conditions but also consider potential high-load conditions.

3. What Is the Final Target Product?

The target product determines what the membrane system needs to “retain” and “remove.”

For example:

●  Fresh milk sterilization focuses on removing microorganisms;

●  Whey protein production requires consideration of casein and whey protein separation first;

●  High-protein products require higher protein retention;

●  Low-lactose products require reduced lactose content;

●  Concentrated milk focuses on water removal;

●  Greek yogurt requires comprehensive consideration of protein concentration, lactose and salt removal, and texture.

Without a clear target product, the appropriate membrane specifications cannot be accurately determined.

4. What Are the Product Specification Requirements?

In addition to the product name, it is necessary to clarify:

●  Target protein concentration;

●  Allowable lactose residual level;

●  Salt content;

●  Total solids concentration;

●  Product purity;

●  Microbial control requirements;

●  Flavor and heat sensitivity requirements.

Even for the same whey protein product, different purity and concentration requirements can result in different process configurations, membrane areas, and investment levels.

5. How Much Feed Needs to Be Processed, and How Is Production Organized?

It is necessary to specify:

●  Daily processing capacity or hourly processing capacity;

●  Daily operating hours;

●  Continuous or batch production;

●  Volume of each production batch;

●  Seasonal production variations;

●  Whether expansion capacity needs to be reserved.

Designing a membrane system based on average flow rates may not meet peak production requirements, while designing based on maximum flow rates may result in unnecessary investment and underutilized membrane area. Therefore, the system design should be determined based on the actual production schedule.

6. What Is the Main Problem with the Current Production Line?

For existing membrane system upgrades, the problems need to be clearly identified:

●  Rapid flux decline;

●  High cleaning frequency;

●  Poor recovery after cleaning;

●  Frequent membrane replacement;

●  Low protein yield;

●  Unstable product quality;

●  High energy consumption;

●  Microbial risks;

●  Excessive manual operation.

The same issue of “poor performance” may result from different causes, such as unsuitable membrane materials, insufficient pretreatment, improper operating parameters, or inadequate cleaning procedures. The solutions can therefore be completely different.

The dairy purification challenges highlighted in the livestream materials were summarized as low yield, severe fouling, and high equipment costs. It was also emphasized that yield improvement requires the combined support of products, technology, and application experience.

7. What Cleaning and Sterilization Conditions Are Required?

It is necessary to confirm in advance:

●  Applicable cleaning agents;

●  Acid and alkaline cleaning concentrations;

●  Cleaning temperature;

●  Whether hot water sterilization is required;

●  Whether steam sterilization is required;

●  Cleaning frequency;

●  Storage method during shutdown periods.

Ceramic and polymeric membranes have different tolerance ranges for temperature, chemical conditions, and sterilization methods. Cleaning and sterilization requirements directly influence membrane material selection.

8. What Other Processes Are Included Before and After the Membrane System?

A membrane system never operates independently.

It is necessary to understand whether the upstream process includes centrifugation, filtration, homogenization, sterilization, or other steps, and whether the downstream process connects with evaporation, spray drying, formulation, or wastewater treatment.

For example:

●  Insufficient upstream treatment may increase membrane fouling;

●  Protein separation performance can affect subsequent purification processes;

●  Reverse osmosis pre-concentration can reduce the load of downstream evaporation;

●  The permeate from the membrane system may also have recovery or treatment value.

Only by considering the upstream and downstream processes together can the actual cost savings and value created by the membrane system be accurately evaluated.

What Can Jiuwu Provide?

Jiuwu offers ceramic membranes, polymeric ultrafiltration membranes, nanofiltration membranes, and reverse osmosis membranes. Based on different components in dairy streams, including microorganisms, proteins, lactose, salts, and water, Jiuwu can design customized multi-stage separation processes.

The advantage of Jiuwu lies in integrating membrane materials, process design, complete equipment, and application experience:

●  Selecting suitable membrane specifications based on different target products;

●  Determining the appropriate application scenarios for ceramic and polymeric membranes according to fouling conditions;

●  Combining sterilization, protein fractionation, lactose and salt removal, and concentration processes;

●  Designing integrated solutions together with upstream and downstream processes.

Before finalizing equipment configuration, verification based on actual feed materials and technical requirements is still necessary.

When preparing project information, customers can first organize the requirements into a one-page checklist based on these eight questions. The more complete the information, the easier it is for engineers to determine the suitable membrane type, process route, and equipment scale, while reducing repeated communication in the early stage and making quotations closer to actual project requirements.