China: new LNG liquefaction technologies? 

When do you hear about “new technologies?” in gas liquefaction in China, the first thing that comes to mind is probably giant plants, megaprojects and numbers in billions of cubic meters. But if you dig deeper, into the “kitchen” itself. process, it becomes clear that the real revolution often lies not in scale, but in the details: in adapting standard solutions to local conditions, in optimizing equipment supply chains, in combating specific, sometimes completely unexpected, technological bottlenecks. And here the experience of Chinese engineers and design institutes, which have gone from importing technologies to their deep processing, becomes especially interesting. This is not a simple race for performance, but rather a complex process of “grinding in?” global technologies to Chinese reality.

From import to adaptation: where do the real challenges lie?

Many people mistakenly believe that the main task is to simply buy a license for, say, liquefaction technology from some Western giant and reproduce it. In fact, the hardest part comes later. Climatic conditions, the quality of local steel for heat exchangers, energy efficiency requirements, which in China may be even stricter due to the “green” policy. development - all this forces us to make serious adjustments. I remember how on one of the projectsmini LNGthe standard liquefaction cycle refused to operate stably under the sudden changes in ambient temperature that are characteristic of certain regions of China. We actually had to re-calculate and configure the control system, and not just “turn it on and forget it”.

It is in this niche - adaptation and optimization - that many Chinese design institutes are actively working. Let's take, for example,Chengdu Yizhi Technology Co.(their website ishttps://www.yzkjhx.ru). This is not just an office with draftsmen. The institute was established in 2013 by Huaxi Technology with a registered capital of 120 million yuan, which indicates serious intentions. Their value often lies not in the creation of some completely new liquefaction technology from scratch, but in deep engineering study. They can take a well-known process, say, based on the nitrogen cycle or a mixed refrigerant, and modify it for a specific raw material - for example, associated petroleum gas with an unstable composition, which is typical for many fields. This is the same “new technology?” in an applied sense: not the discovery of a new physical principle, but the creation of a reliable and economical solution from available components.

A common problem that you encounter in practice is logistics and localization of equipment. Ordering each valve or special pump from Europe involves enormous time and cost. Therefore, part of the work of such institutes is aimed at finding and qualifying local manufacturers, testing their products, and making changes to the design so that domestic analogues can be used without loss of reliability. Sometimes this is successful, sometimes it is not - and then the project faces a long wait for imported supplies. This is a reality that is rarely written about in glossy brochures.

Focus on energy efficiency and "green" solutions

Today, simply liquefying gas is not enough. This must be done with minimal energy consumption. Trend onenergy efficiencyin China is dictated not only by the economy, but also by strict government regulations. Therefore, many “innovations” relate specifically to heat recovery, optimization of refrigeration cycles, integration of liquefaction plants with other industries to use waste heat. For example, it is interesting to observe projects whereLNG plantis being built next to a chemical plant - the heat from exothermic reactions can be tried to be utilized in the process of regasification or pre-cooling.

But there are also pitfalls here. Theoretical calculations of energy savings can be disrupted in practice. At one of the sites, an attempt to use low-grade heat from a neighboring production to heat the refrigerant in the liquefaction cycle encountered the problem of instability of this same heat flow. When chemists changed the operating mode of their installation, our liquefaction system began to “suffocate”. It was necessary to develop a complex buffer system and control algorithms that negated part of the economic effect. It turned out that it is sometimes easier and more reliable to have your own independent source of energy, albeit a less “green” one. on paper.

In this context, design institutes like the aforementioned Chengdu Yizhi Technology Co. Ltd. often act as integrators who must calculate all these risks. Their task is not to draw an ideal diagram, but to design an installation that works and, what is important, is repairable in the conditions of a particular region. Sometimes this means a conscious refusal to be too complex and “fancy”? decisions in favor of rougher, but proven ones.

Mini- and micro-LNG: a testing ground for innovation?

While large onshore and floating plants are getting most of the attention, I believe that plants are becoming the real laboratory for new technological approaches.mini LNGand micro-LNG. Their relatively small scale makes it possible to quickly test new circuits, experiment with refrigerants, and implement modular solutions. This is where Chinese companies are being more flexible.

A classic example is the use of liquefaction for the utilization of APG (associated petroleum gas) in remote fields. Standard large technologies are not suitable here due to small volumes and flow instability. A compact, mobile or easily transportable solution is required. And here developments appear based on, for example, turboexpander cycles or cycles with pre-cooling with propane, but in a greatly reduced and simplified design. The key challenge is not efficiency, but namely “survivability,” the ability to work for a long time without the constant presence of highly qualified personnel and with a minimum of maintenance.

On such projects, solutions are often tested, which are then possibly scaled up. The problem with filtration of raw materials before liquefaction, the fight against hydrate formation in miniature heat exchangers, automation issues - all this is solved in the field? conditions. And often these solutions are of a purely applied, even artisanal nature at first glance, but it is they who constitute the very practical experience that cannot be bought for any license fees.

Equipment and materials: hidden front of work

When talking about technology, we cannot ignore hardware. Breakthrough inliquefaction technologiesoften depends on the availability of special materials and equipment. The main heat exchanger is the heart of any installation. The production of spiral-wound heat exchangers has long been a monopoly of a couple of Western companies. Now Chinese manufacturers are actively developing this market, but the path is difficult. The quality of aluminum strips, soldering techniques, quality control - all this requires the accumulation of experience.

I saw how on one of the first projects using a domestic heat exchanger of this type, a microcrack appeared in the solder seam after several start-stop cycles. The reason is the different coefficient of thermal expansion of materials in a specific temperature range, which was not fully taken into account. This led to a shutdown of several months for replacements. The experience gained in such situations is invaluable. It directly affects the adjustment of production flow charts and, ultimately, the reliability of the entire chain.

The work of design institutes in this part consists of close dialogue with equipment manufacturers. They transmit to them data from real operational facilities: where stresses arise, which modes are the most severe, which impurities in the gas are the most aggressive. This is an iterative process that moves the industry as a whole forward. A company acting as a designer and integrator, for example,Chengdu Yizhi Technology Co., in such conditions becomes an important link connecting fundamental science, mechanical engineering and the final operator.

Looking ahead: what will drive the industry?

Based on what is seen in practice, the driver of development will not be so much revolutionary discoveries as gradual evolution in several directions. The first is digitalization and predictive analytics. Implementation of sensors and data analysis systems to predict equipment wear, optimize operating modes in real time, especially for floating installations or remote objects. The second is further work on technology flexibility. Plants must be able to operate efficiently with a wider range of gas compositions, which is critical for the development of distributed energy and the use of biogas.

The third, and perhaps most important, is the accumulation and systematization of that very practical experience. Every failure, every emergency situation at an operating facility is gold. Those companies and institutions that can create a system to collect and analyze this data, and turn it into concrete engineering recommendations, will have a serious advantage. This is the same “know-how” that cannot be copied simply by purchasing drawings.

So, to answer the question in the title, yes, there are new technologies in China. But they are not born in a vacuum, but in the process of solving specific, sometimes very mundane problems: how to avoid the formation of hydrates in this particular pipe, how to extend the life of this compressor by 10%, how to start an installation after a sudden power outage with minimal losses. And it is precisely this applied, sometimes even “stained with fuel oil” experience is shaping the very technological landscape that makes Chinese solutions in the field of gas liquefaction increasingly interesting and competitive not only within the country, but also abroad.