Chinese adsorbents: new technologies? 

When you hear “Chinese adsorbents?”, the first thing that comes to mind is, of course, activated carbon, and even on an industrial scale. Many still believe that China is mainly a supplier of basic, standard sorbents at a low price. New technologies? Skepticism is understandable. But over the past five to seven years, the picture has begun to change, and not at the level of advertising brochures, but in real projects, where specifications are strict and price is not the only criterion. I went through this myself, and I will say this: yes, there is a flow of standard goods, but at the same time a direction is developing that can no longer be ignored.

From ?cheap and a lot? to ?accurately and for the task?

Previously, the main request from the CIS for Chinese adsorbents was simple: “we need cheaper coal for gas drying.” Competition was based on price per ton. Nowadays, technical specifications with parameters on moisture capacity, abrasion resistance, and sorption kinetics at certain pressures are increasingly being received. And this is where things get interesting. Chinese manufacturers, especially those that work in conjunction with serious engineering companies, began to not only listen to these requests, but to work them out.

I remember a project to purify hydrogen from CO2. An adsorbent with a very narrow pore distribution was needed to selectively capture carbon dioxide, but not touch methane. There were European proposals, but they were expensive. Colleagues found a laboratory in China that made modified zeolites. And she didn’t just sell the finished product, but asked for detailed process conditions - temperature, pressure, flow composition. As a result, they sent three different prototypes for testing. This is no longer selling bags, this is pre-design development.

The key change is in the approach. Previously, you bought goods from a catalogue. Now dialogue is increasingly possible: “Do you have such a problem?” Can we adapt the composition or structure to it? This applies not only to zeolites, but also to the same activated carbons - for specific organics in wastewater, or aluminum oxide - for specific processes in petrochemicals. However, there is a nuance here: to reach such suppliers, you need to know where to look. Direct factories are often inflexible. But design institutes or engineering companies that “cultivate” them? for the foreign market is a completely different matter.

Example from practice: not everything worked out right away

I would like to give an example that clearly shows both the potential and the pitfalls. We had an order for molecular sieves for air drying before a cryogenic installation. The European supplier missed the deadline, so we decided to try the Chinese equivalent. We found the manufacturer through partners, requested data, everything looked perfect: both the moisture capacity was at the level and the strength. We ordered a trial batch.

The first problems began when loading into adsorbers. The dust content turned out to be higher than stated. Not critical, but unpleasant - I had to blow it out additionally. Then, during the startup process, we discovered that the dynamic moisture capacity had dropped a little. under cyclic loads. That is, in static conditions, in laboratory conditions, they showed it to be excellent, but in a real cycle of “pressure release-heating?” the picture was a little worse. As a result, the dew point was reached, but the cycle time margin was reduced.

This is a classic story. Laboratory tests in China and local acceptance conditions sometimes differ. Not because of bad will, but because of differences in methods and, frankly, sometimes because of excessive optimism in reports. We came to the following conclusion: Chinese adsorbents for such important tasks are already an option, but pilot testing is required. You can’t blindly trust the passport data; you need to drive in your own conditions. After this incident, we began to build cooperation differently.

The role of engineering: where to look for the right technologies

As I already hinted, finding the right supplier is half the battle. Now many Chinese chemical holdings are creating separate engineering divisions that act as a single window. They don’t just sell a product, but offer a technological scheme, calculations, and then the supply of reagents for it. This relieves a lot of headaches.

Here, for example,Chengdu Yizhi Technology Co. (https://www.yzkjhx.ru). This is just such a case - a design institute created by a chemical technology company. A systematic approach is visible in their work. They can work through the entire cycle: from analysis of the customer’s raw materials and process modeling to the selection or even development of an adsorbent with the required properties and delivery of ready-made modules. For us, this format turned out to be convenient when upgrading a short-cycle heatless adsorption (SCA) installation. It was necessary not only to replace the old zeolite, but to optimize the layered loading (layered loading), taking into account the presence of heavy hydrocarbon impurities in the flow. Yizhi Technology offered their calculation and combination of their zeolite with a special aluminum gel to capture heavy fractions. The result was good.

The point is that on their ownChinese adsorbents- this is raw material. And their application technologies are already added value, which was previously lacking. When an engineer talks to you who understands the difference between PSA and TSA, and can justify why this particular type of pore is needed in your case, it builds trust. Companies like Yizhi bridge the gap between an advanced Chinese laboratory and our manufacturer.

What's in the arsenal? Not only zeolites

When talking about new technologies, everyone immediately thinks about zeolites. Yes, their range is expanding: mesoporous structures and zeolites with ions of different metals (Ag, Cu, Zn) are appearing for special tasks, for example, for simultaneous drying and removal of sulfur compounds. But there are other interesting directions.

For example, activated carbon based on coal tar (coal tar pitch) with very high density and mechanical strength. For adsorbers with frequent cycles and vibration - an excellent solution. Or modified aluminum oxides with increased stability against liquid water. I have seen their use in natural gas dehydration installations in small fields where conditions are unstable.

A separate topic is spent adsorbents. In Europe, recycling or regeneration is strict. The Chinese often offer the “product + return export and processing” scheme. This can be economically beneficial, but here you need to look deeply at environmental legislation and the real possibilities of regeneration. Have you heard of cases where ?regeneration? in reality it was just a burial. So this is a double-edged sword: the technology for offering a full cycle is there, but control over its implementation is a matter of trust and strict control in the contract.

Conclusions and look ahead

So, back to the title question. New technologies in the fieldChinese adsorbents? Yes, they exist and are actively developing. But the main novelty is not in the discovery of some magical material (although R&D is active), but in the change in the business model and the depth of involvement. From selling tons to solving technological problems.

Is it possible to recklessly switch to Chinese sorbents in critical processes? No, careful validation is required. But now, for many standard and even semi-standard tasks (gas drying, hydrogen purification, some types of wastewater treatment), they represent a strong alternative with a better price-functionality ratio.

The future, as I see it, lies in hybrid solutions. When basic engineering and key equipment can be European, and the selection and supply of adsorbents can be from Chinese technology partners who have proven their competence in specific projects. Risks remain, but they are becoming manageable. And ignoring this market segment already means, perhaps, losing economic efficiency. The key is to approach with an open mind, but with healthy, practical caution.