Many regions around the world pay more and more attention to environmental protection and energy saving, driving more environmentally friendly new energy to be widely used around the world. The author visited Japan earlier to learn about the construction and application of hydrogen power generation facilities in Japan, which are large enough to supply a number of power-hungry infrastructure, including large hospitals that operate 24 hours a day. In addition, the pressurized liquefied hydrogen can also be transported to the car filling station, and the gas supply is given to the hydrogen fuel cell in the electric vehicle, and the power generation is chemically used to supply the needs of the car, so the use of hydrogen is not only becoming more and more popular, but may also become one of the main energy supplies to achieve sustainable social development in the future.

Written by: Senior Engineer and Former President of the Institution of Engineers, Yuen Pak Leung

When I visited a hydrogen refueling station in an urban area in Japan, I just came across a mobile hydrogen truck.

As mentioned in the previous article, the author traveled to Japan with the engineering industry earlier, visiting the world's first all-hydrogen power generation facility in Osaka, which mainly burns hydrogen and generates a large amount of electricity through turbine power generation for use by neighboring large-scale facilities. In fact, when I visited the mainland about 20 years ago, China was vigorously developing the supply chain and application of hydrogen energy, and had already developed relevant standards for its use, especially in terms of safety.

In fact, there are different discussions on the use of hydrogen in the environmental engineering industry around the world, although the efficiency of fuel cells made of hydrogen is high, up to 60%, and even 85% efficiency when applied to electric heat and heat generation, there are also opinions that some hydrogen may not be environmentally friendly when used.

Hydrogen can be divided into several types, such as hydrogen called "gray hydrogen" in the color representation, which is produced by the recombination of natural gas through vapor, which is more expensive; "Blue hydrogen" is through the carbon emission in the process of gasification or vapor recombination, through carbon capture and storage to avoid emission into the atmosphere, so the hydrogen produced is called "blue hydrogen"; As for blue-green hydrogen, natural gas is separated by thermal cracking technology, and the carbon dioxide in it is turned into solid storage to become hydrogen. However, the pyrolysis process requires a large amount of fuel to generate thermal energy, resulting in low energy efficiency and high technical cost, and if the production process produces carbon emissions, it will also reduce the carbon reduction effect of blue-green hydrogen. However, relatively speaking, the use of hydrogen for power generation is still more environmentally friendly than the current reliance on fossil fuels for power generation.

When I was visiting Japan, I came across a hydrogen and oxygen vehicle refueling station in the urban area.

As for the hydrogen used in the power plants I visited during my visit to Japan, it is regarded as the most environmentally friendly "green hydrogen", because it is produced by electrolysis of solar and wind energy, and not only does not aggravate carbon emissions during production, but uses pure renewable energy production, so many regions have successively built solar farms in more remote places to produce "green hydrogen" gas and send it to different regions for use.

However, this may lead to the high cost of transporting the fuel source, but in fact, as long as it is liquefied, it can already facilitate storage and transportation, and can also reduce the related transportation costs. The author believes that although the current global hydrogen supply chain is not yet perfect, it does not mean that it is necessary to wait until there is a full supply of green hydrogen to start the trial, and governments have vigorously carried out hydrogen power generation, especially from the easier to start in the aspect of transportation, in the application process to continuously update and strengthen the facilities, to form a more complete supply chain.

In addition to using hydrogen power generation to supply different facilities, Japan will also liquefy hydrogen and transport it to car filling stations for electric vehicles, and cars can produce electricity to drive car motors through built-in fuel cells, so that hydrogen and oxygen produce chemical action to drive car motors, and only discharge water, do not produce pollutants.

When the author visited another hydrogen refueling station in Japan, in addition to the hydrogen bus I was riding on that needed to be refueled, other private cars arrived to queue up for hydrogenation.

This method is also gradually used on a large scale in the local area, and the heat generated by vehicles propelled by hydrogen is more than that generated by ordinary combustion of natural gas and diesel, not only the vehicle has a stronger range, but the hydrogen charging time will be much shorter than that of ordinary electric vehicles. According to hydrogen energy vehicle manufacturers, a household hydrogen vehicle is filled with hydrogen in minutes, not that electric vehicles on the market today generally need more than hours to fully charge, hydrogen charging is as fast as gasoline vehicles refueling on the road.

The author (second from left) visited a hydrogen refueling station in Anting, Jiading District, Shanghai about 20 years ago when he visited China.

In addition to Japan, in recent years, it has been reported that some hospitals in Israel have introduced the use of hydrogen power generation, which can be regarded as the first hospital to continuously supply power with hydrogen energy. Since the cost of hydrogen power generation may be higher than that of traditional power generation methods, most of the government subsidizes the initial stage of operation, and the electricity generally obtained is mostly used for public affairs. In the face of increasing power dips and accidents, the author believes that the authorities should study whether Hong Kong has the potential to supply partial or backup use of hydrogen power generation, such as government facilities and hospitals, so as not only to mitigate the possible impact of power accidents, but also to achieve the comprehensive carbon reduction targets proposed by the authorities.

"01 Medical Clinic" cooperated with senior engineer Yuen Pak Leung to launch a special column "The Source Road to You" every Monday to share big and small events in engineering and medical treatment.

Yuen Pak Leung has always been committed to promoting the professional development of the engineering profession and is the past President of the Hong Kong Institution of Engineers. Decades of professional journey are indeed worth remembering, and I believe that those who come after may be able to understand the key points of engineering profession. If there is you in the source, let everyone experience it together.

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