I originally thought that buying soy sauce and making sugar every day was too unimpressive and not “high-class,” but then my boss told me that this is actually a market worth hundreds of billions of yuan.

Summary of the Key Points

This article tells the story of how Luo Jianquan, a researcher at the Chinese Academy of Sciences (referred to as the "Membrane Master"), transformed membrane technology from the laboratory to industrial applications. By utilizing "smart sieves" similar to cell membranes, he solved challenges in traditional industries such as soy sauce desalination and green sugar production. The process involved transitioning from small-scale laboratory tests to pilot projects in factories, and finally to demonstration projects. Along the way, they overcame various difficulties related to technology scaling, cost control, and contamination. The success of this technology in a market worth hundreds of billions of yuan highlights the importance of conducting research that addresses real-world problems.

1. What is Membrane Technology? "Smart Sieves" Like Cell Membranes

Membrane technology may sound advanced, but its principle is similar to that of cell membranes in middle school biology: both act as selective barriers. Cell membranes allow useful substances to pass through while blocking unwanted ones. Separation membranes, on the other hand, have different pore sizes:

• Microfiltration membranes: Large pores (0.1-10 micrometers), similar to masks, can filter out bacteria and sediment.
• Ultrafiltration membranes: Small pores (under 100 nanometers), capable of removing viruses and proteins.
• Nanofiltration membranes: Even smaller pores (under 2 nanometers), which allow small organic molecules (such as amino acids in soy sauce) to pass through while retaining salts (single-ion compounds).
• Reverse osmosis membranes: The smallest pores (a few nanometers), used for producing purified water in home water purifiers and desalination processes.

These membranes may look like ordinary A4 paper, but under a microscope, they have a three-layer structure with nanoscale pores, which is where their technological value lies.

2. Research on Soy Sauce: Making Low-Salt Soy Sauce More Accessible

Luo Jianquan's first research project focused on soy sauce desalination:

• Why desalinate? Soy sauce contains up to 20% salt, which is unsuitable for people with kidney diseases. However, reducing the salt content too much would diminish its flavor. Membrane technology allows the retention of amino acids, the source of the soy sauce's umami, while allowing salt to pass through, resulting in low-salt soy sauce.
• Challenges in the Transition from Laboratory to Factory: Although the technology worked well in the laboratory, problems arose during the pilot test at a soy sauce factory in Foshan. The equipment would frequently stop working due to electrical issues, which were resolved with remote guidance from his father, who is an electrician.
• The Benefits: The new technology made the soy sauce clearer, with less sediment, and extended its shelf life. It also enabled the production of soy sauce with different salt levels to meet various consumer needs.

3. Sugar Production Using Membrane Technology: A Billion-Dollar Market Free from Traditional Challenges

After returning to China, Luo Jianquan was assigned a project on "green sugar production":

• Problems with Traditional Sugar Production: The traditional method uses chemicals like sulfurous acid and lime, which not only affect sugar quality but also lead to scaling and increased energy consumption. Additionally, 20% of the sugar is wasted in the form of molasses.
• Advantages of Membrane Technology: It uses purely physical separation methods without chemicals. Three membranes with different pore sizes are used to sequentially remove suspended solids, pigments, and inorganic salts, ultimately producing pure sucrose. Byproducts can be used to make brown sugar, electrolyte water, and organic fertilizer.
• Overcoming Challenges: During the demonstration project, half of the membrane tubes became clogged. It turned out that the clogging was caused by glucan, a sticky substance produced by bacteria (Enterococcus faecalis) in the sugarcane. This issue was solved by using bioenzymes to degrade the glucan and then cleaning the membranes.
• Results: The resulting "membrane-produced white sugar" was whiter, and the crystallization residue was so clean that it could be consumed directly. This research led to an SCI paper and even a gift to a Russian friend, representing an export success.

4. The Challenges of Transitioning from Laboratory to Industrialization

Turning laboratory technology into industrial applications is not straightforward:

• Technology Scaling: Laboratory experiments use small equipment and clean materials, while factories process sugarcane that contains sediment and fibers. If the pretreatment system is inadequate, it can cause membrane clogging.
• Cost Control: Since sugar is inexpensive, expensive membranes cannot be used. Therefore, a combination of multiple membranes is required, and the cost must be offset by generating revenue from byproducts.
• Unpredictable Issues: Bacteria may evolve and develop resistance, requiring constant adjustments to the process (e.g., by adjusting pH levels or using bioenzymes).
• Domestication and Cost Reduction: Membrane technology used in the biomedical industry still relies on imports, and there is a need to develop domestic alternatives to reduce costs.

5. Research Goes Beyond Papers: Applying Technology in Real-World Settings

Luo Jianquan believes that research should not be limited to writing papers in the laboratory; it must also be applied in practical settings. His work has shown that seemingly mundane tasks like soy sauce production and sugar manufacturing can benefit significantly from advanced technology. His membrane technology not only improves the quality of products but can also be used in wastewater treatment and biomedicine, truly driving industrial upgrades.

In his words: "Scientists should be able to both lecture in the classroom and work in the workshop."

This article demonstrates that seemingly ordinary processes like soy sauce production and sugar manufacturing can be powered by cutting-edge technology. Research that is integrated into real-world applications creates real value.