Helium, the second most abundant element in the Milky Way after hydrogen, is surprisingly scarce on Earth as a non-renewable resource. In recent years, with rising global demand, reports of helium shortages have become increasingly common.
Although less visible than oil or natural gas in daily life, helium plays an indispensable role across industries—from filling balloons to critical applications in electronics, biomedicine, and aerospace. It is a foundational material for high-tech industries, and its shortage could lead to severe consequences.
Currently, China heavily relies on helium imports, with prices doubling over the past three to four years. Faced with this "helium shortage," how should China respond?
Exploration is imminent
Helium is primarily associated with natural gas or radioactive ores and is also known as the "noble gas."
In the past, helium, as a chemically stable, low-density inert gas, was primarily used as a shielding gas in welding processes and as a filling gas for airships. With the rapid advancement of technology, people have discovered that helium's excellent properties can also shine in other applications.
With the development of aerospace technology, helium has been further utilized as a fuel pressurant and purge gas. Its extreme diffusibility makes it an excellent leak detection gas. Thanks to its superior thermal conductivity, helium also serves as a heat transfer medium for crystal growth in the electronics industry. The temperature of liquid helium approaches absolute zero, making it suitable as a cryogenic coolant and refrigerant, enabling low-temperature superconductivity and superfluidity.
"The extensive uses of helium are determined by its unique properties, and humanity has yet to find a substance that can completely replace helium," Hu Zhongjun, an associate researcher at the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences, told Science and Technology Daily.
Meanwhile, helium resources are unevenly distributed globally. According to estimates by the U.S. Geological Survey, the United States, Algeria, Qatar, Russia, and Canada hold approximately 92% of the world's helium resources.
Currently, China's discovered natural gas fields with significant helium content are mainly located in the Weihe Basin, Sichuan, and the Tarim Basin, among other regions. However, only a few helium gas fields have achieved industrial-scale development, and domestic helium production falls far short of meeting the demands of scientific, technological, and economic development.
"The distribution of helium gas fields in our country is scattered, and their quality is generally poor with low helium content, making extraction costs high, which dampens the industry's enthusiasm for commercialization," said Fu Guomin, a professor at the School of Resources at Chang'an University. "What's more regrettable is that during the early stages of geological resource exploration in China, people failed to recognize the importance of helium and did not prioritize helium exploration as a key objective, resulting in a lack of data on helium reserves in many gas fields."
In recent years, research on China's potential helium resources has gradually gained momentum. Geologists believe that over 95% of helium reserves are distributed in ancient platforms. Based on this, some experts predict that the Sichuan Basin and the Ordos Basin may be favorable regions for China's proven helium resources. Fu Guomin added that foreland fault depressions can also form helium enrichment, and although the reserve scale may not be as large as that of ancient platforms, it is still worth paying attention to in future natural gas exploration.
Hu Zhongjun stated that a major challenge facing China's helium industry is the unclear understanding of helium resources. There is a need to explore and investigate new helium deposits and establish helium plants, especially large-scale helium liquefaction plants, in suitable areas for extraction to achieve economically viable long-distance helium transportation.
Helium extraction technology urgently needs upgrading.
Helium production primarily employs cryogenic condensation and separation processes, involving three main steps: pretreatment and purification, crude helium extraction, and pure helium refining, ultimately yielding pure helium. Fu Guomin noted that China faces no insurmountable technological bottlenecks in helium production, with the main difficulty lying in the scarcity of high-quality helium fields.
Generally, natural gas must contain helium at a concentration of at least 0.1% to be economically viable for extraction. In the United States, helium content in natural gas fields ranges from approximately 0.8% to 7.5%. Natural gas with a helium content exceeding 0.3% is typically considered helium-rich, whereas most of China's natural gas fields currently have helium concentrations far below this level.
To address this, Hu Zhongjun proposed that China should focus on researching and developing helium extraction processes for helium-poor and helium-bearing natural gas. This includes improving existing cryogenic helium extraction equipment and techniques to reduce energy consumption, as well as developing hybrid processes that combine cryogenic, adsorption, and membrane separation methods. Additionally, leveraging LNG co-production and scaling up production could help lower helium extraction costs.
Additionally, the concentration of helium in the atmosphere is extremely low, approximately five parts per million. Even natural gas considered economically valueless due to its low helium content contains helium at levels two orders of magnitude higher than atmospheric helium.
Hu Zhongjun stated that when necessary, helium can be extracted from air separation vent gas, ammonia synthesis tail gas, helium-rich monazite, hot spring gas, and pit gas from gold-uranium mines. Taking air vent gas as an example, he explained that nitrogen and oxygen in the air are both important industrial gases. After these two gases are extracted, the relative concentration of helium in the remaining gas increases, giving it certain commercial value for helium extraction.
Strengthening cutting-edge research
Currently, some of China's high-tech industries still occupy the lower end of the global industrial chain. High-end production processes in industries such as electronics and information technology have a significant demand for helium. With the upgrading of China's high-tech industries, the demand for helium is expected to further increase.
Hu Zhongjun emphasized that, in addition to enhancing exploration and technological advancements, greater attention should be paid to fundamental research related to helium. At present, human understanding of helium source evaluation parameters, helium release mechanisms, the transport mechanisms and controlling factors of helium in complex geological media, as well as the formation processes and key controlling factors of helium-rich gas reservoirs, remains incomplete.
"Similar to oil and natural gas, helium resource exploration is costly, often requiring tens of millions of yuan for just one drilling well. Strengthening research on helium enrichment patterns can significantly improve exploration efficiency," said Fu Guomin.
Recently, the "Mechanism of Helium-rich Natural Gas Accumulation and Prediction Technology for Helium Resource Distribution" has been included in the 2021 key special project "Critical Scientific Issues of Transformative Technologies," with related application work already initiated.
Hu Zhongjun stated that the widespread attention and involvement of industry scholars will significantly advance research on helium generation, storage patterns, and recycling, making the future of better human utilization of helium resources highly promising.
This article is sourced from China Science Daily (April 12, 2021, Page 3, Energy and Chemical Industry).