Hydrogen has been hailed as the "ultimate energy source" and is internationally recognized as a clean energy source, but it has not yet been applied on a large scale. The fundamental reason for this is that hydrogen has a very stubborn characteristic: it is flammable, explosive, and difficult to store and transport at room temperature and pressure. The former U.S. Secretary of Energy, Steven Chu, summarized it as one of the four major problems in the use of hydrogen energy. Therefore, breaking through the bottleneck of hydrogen application has become a dream goal for the scientific community. The team of Prof. Dr. Hansong Cheng, Distinguished Professor of China University of Geosciences (CUG), has successfully overcome the technological bottleneck of large-scale application of hydrogen energy, and developed the technology of organic liquid hydrogen storage under normal temperature and pressure.

Prof. Dr. Hansong Cheng studied under China's famous chemist Tang Aoqing, and later received his PhD from Princeton University in the US, majoring in theoretical chemistry. He has worked for the US Department of Energy and AP.

Prof. Dr. Hansong Cheng (first from left) introduces hydrogen oil research and development to Tian Li, President of Qidi Handan Research Institute (in preparation) and his delegation.

At present, the development of the domestic hydrogen energy industry is still facing four problems, which are the four major challenges mentioned by Steven Chu: firstly, the need to have abundant sources of hydrogen, secondly, the storage and transport of hydrogen at room temperature and high pressure, thirdly, cheap, efficient and long-life fuel cells, and fourthly, the need for adequate infrastructure. Therefore, how to solve the four major problems raised by Steven Chu and better develop and utilise hydrogen energy has become the most pressing issue at present.

On 7th July, the editor of Wuanjun followed Tian Li, Senior Vice President of Qidi (Holdings) and President of Qidi Handan Industrial Technology Research Institute (in preparation), to visit Wuhan. The editor of Wuanjun had a close interview with Prof. Dr. Hansong Cheng, Director of Sustainable Energy Laboratory of China University of Geosciences (Wuhan). Professor Hansong Cheng answered the reporter's questions on the development status of organic liquid hydrogen storage technology, technological progress, the future market prospects of hydrogen energy and fuel cells and other industry hot issues.

First from left: Tian Li, President of Qidi Handan Industrial Technology Research Institute

Reporter: What is the situation in China regarding the four major challenges of hydrogen energy application mentioned by Steven Chu?

Professor Hansong Cheng said, at present, from the domestic development situation, a large number of industrial by-production of hydrogen and abandoned wind, light and water discarded electricity, as well as the emergence of reasonably priced, long-life fuel cells, has solved the two major challenges in the development of the hydrogen economy, the next need to deal with is the level of hydrogen storage and transport and infrastructure construction. The infrastructure development has benefited from the new infrastructure carried out after the COVID-19 epidemic, so it is not a big problem in China. The only problem is the way of storage and transport of hydrogen energy, the maturity of the technology or not, the technical issues determine the scale of investment in the new infrastructure and the timing of construction, so breakthroughs in the use of hydrogen energy key technologies, research and development of normal temperature and pressure conditions, safe, efficient and cheap liquid hydrogen storage technology is of great practical significance.

Reporter: At present, the domestic hydrogen energy use in full swing, the title of the hydrogen valley of the name of the development zone is common, a variety of technical routes are endless. However, in terms of hydrogen storage and transport, the main way is still high-pressure hydrogen storage, pressure use, etc., the safety issue has become the primary problem.

Hynertech’s Hydrogen buses have been put into operation

    Professor Cheng said that in order to realize the marketable and large-scale application of hydrogen storage technology, it is necessary to take the lead in solving the problem of hydrogen refueling stations. If we adopt our liquid organic hydrogen storage technology from Hynertech, then there will be no such problem in many aspects such as hydrogen storage, hydrogen transport, refueling and use, and it will be very safe.

    Compared to high-pressure gaseous hydrogen storage, low-temperature liquefaction hydrogen storage technology and other chemical hydrogen storage technologies, organic liquid hydrogen storage technology has the following very important characteristics:

Firstly, organic liquid hydrogen storage technology has a higher volumetric hydrogen storage density than high-pressure hydrogen, containing only 39 grams of hydrogen per litre at 700 atmospheres. China is currently using 350 atmospheres, containing 20 grams of hydrogen per 1 litre. Deep cold liquefaction to -253 ℃, each 1 litre contains 70 grams of hydrogen. Our organic liquid hydrogen storage technology can achieve nearly 60 grams of hydrogen per litre at room temperature and pressure, so its hydrogen storage capacity is very high.

Secondly, organic liquid hydrogen storage can match well with existing petrol stations and other infrastructures, only a small amount of modification to the existing petrol station can be quickly transformed into a hydrogen refueling station, and the cost of equipment to build a hydrogen refueling station is only more than 200,000 RMB. Compared to other hydrogen refueling stations that can cost tens of millions of dollars to build, Hynertech's hydrogen refueling stations are very economical, and large petroleum refineries can be magnificently transformed into hydrogen oil manufacturing plants. Since hydrogen oil hydrogen from a wide range of sources, such as coal and other rich organic matter can be obtained, oil storage and can be used repeatedly, therefore, the large-scale promotion of hydrogen oil hydrogen storage technology to protect China's energy security is also of great significance.

Hydrogen oil refueling stations and hydrogen oil storage tanks

Thirdly, organic liquid hydrogen storage technology has low energy consumption on the user side, and the transport is very safe and convenient, which can effectively reduce the cost of use on the user side.

Reporter: Professor Cheng, on the user side, how is hydrogen released from hydrogen oil? Can the storage oil be recycled?

Prof. Dr. Hansong Cheng: At the user end, such as in automobiles, hydrogen is released from stored oil at a temperature of 200°C and with a specialized catalyst. So where does such a temperature come from? Because the fuel cell waste heat quality is so low, only 70 degrees, it is difficult to turn 70 degrees into 200 degrees. Therefore, it is necessary to do two things: one is to increase the fuel cell operating temperature, so that hydrogen can be released by using waste heat; there is another way, that is, to let the hydrogen oil react directly on the membrane electrode of the fuel cell, interrupting the carbon-hydrogen bond, and the hydrogen goes directly into the fuel cell, and the product is the storage oil and electricity, and this is the final solution.

Reporter: What is the progress of related technology research and development abroad?

Prof. Dr. Hansong Cheng: The way of storing hydrogen in organic liquids is related to the choice of hydrogen storage carrier and catalyst. In Japan, for example, in the early days, the Japanese government took the lead, with eight ministries working together, and many well-known companies, such as Nippon Iwatani and Toyota, were actively involved. They also hoped to adopt liquid organic hydrogen storage to store and transport hydrogen. However, the carrier chosen by Japan is toluene, which is highly toxic and volatile. Hydrogen can be easily added to it, while it is very difficult to remove it. Germany's organic liquid hydrogen storage technology also encountered similar problems in Japan. Of course, both Europe and Japan are continuously exploring and developing. In this regard, we can proudly say that Hynertech's liquid hydrogen storage technology is already at the forefront of the times.

Reporter: What advantages does Hynertech have in organic liquid hydrogen storage technology and what are the prospects for development?

Prof. Dr. Hansong Cheng: Hynertech's organic liquid hydrogen storage technology is the most advanced in the world. In China, Hynertech is the only high-tech company engaged in the research and development of organic liquid hydrogen storage technology.

Germany has also been developing organic hydrogen storage technology in recent years, and was nominated for the Presidential Prize for Science and Innovation in 2018. However, the

German technology requires a dehydrogenation temperature of more than 300 Celsius degrees, a slower dehydrogenation speed, and a platinum catalyst. Hynertech's dehydrogenation temperature is only 200 Celsius degrees, and its speed is 20-30 times faster than theirs. In terms of dehydrogenation equipment, the advantages are also obvious.

Reporter: What are the advantages of Hynertech's hydrogen oil technology compared to methanol hydrogen storage methanol fuel cell technology?

Prof. Dr. Hansong Cheng: Methanol is also a good and important medium for hydrogen storage, widely available and cheap. However, methanol hydrogen storage is irreversible, burned and gone, and methanol fuel cells have CO2 emissions. In addition, gas separation and purification after methanol decomposition is also a headache. Hynertech is a reversible hydrogen storage technology. That is to say, the carrier used in hydrogen solar energy is not consumed, stored in and released, it can be reused, and can be used repeatedly.

Reporter: What progress has been made in the development of national standards for liquid hydrogen storage technology, and what difficulties have been encountered in its promotion?

Prof. Dr. Hansong Cheng: At present, the international standard for high-pressure hydrogen has been released, but the standard for organic liquid hydrogen storage has not yet been formulated. Our industry alliance has done some group standards, and is now working with China Automotive Research Institute, the National Institute of Standards, the South Network and other units to do the organic liquid hydrogen storage standards, has released several enterprise standards and group standards. The development of organic liquid hydrogen storage standards is conducive to the application and promotion of organic liquid hydrogen storage technology.

At present, the organic liquid hydrogen storage technology to carry out large-scale promotion and application of the technology has not been any problem, the biggest obstacle may still be insufficient awareness of it. Because at present the mainstream technology at home and abroad still adopts the high-pressure hydrogen storage, Toyota is also high-pressure hydrogen storage. Thus, some people think that it is impossible for the Chinese to surpass foreign technologies. In fact, although in general, China's scientific research conditions and scientific and technological strength is not as good as that of foreign countries, but a single technology to surpass is completely possible.

Reporter: Could Professor Cheng please introduce the research and development of fuel cell proton membrane in Hynertech?

Prof. Dr. Hansong Cheng: The low-cost proton exchange membrane suitable for medium to high temperatures (150-200C) has been completed for pilot testing, and the next stage will be catalyst coating.

Reporter: Professor Cheng, would you please talk about Hydrogen Sun's product development in the field of hydrogen oil derivatives?

The company's research and development of hydrogen oil-powered heat, power and cooling triple-supply technology has basically matured and has the conditions for large-scale promotion.

On the issue of hydrogen source, Hynertech, together with China Fifth Ring Engineering Company, has also developed high-temperature rubbish gasification to hydrogen oil technology to deal with municipal rubbish and industrial solid wastes, and has built an experimental plant in Wuhan, the future promotion of which will likely be the end of organic solid wastes and become an important source of hydrogen. Various technologies developed by Hynertech have been granted or are in the process of applying for nearly 100 invention patents and utility model patents by the State Intellectual Property Office (SIPO) and related countries.

Article reprinted from WeChat public number "Wuanjun".