Mr. Nguyen Quang Huy, Department of Energy Saving and Sustainable Development

I. Chemical energy

Chemical energy is the potential of a chemical substance to undergo transformation through a chemical reaction or nuclear reaction to form other chemical substances that can be absorbed or produced. generate energy.

Judging from the above concept, especially chemical processes that produce large amounts of energy have been widely researched and applied by humans and achieved the development achievements of the energy industry today, specifically:

– The process of burning coal (carbon), gasoline (CxHy), gas, and biomass (CxHyOz) all generate heat and mechanical energy. The generated heat energy has been used by humans directly in daily activities such as direct cooking, heating... or through devices that convert heat energy into mechanical energy to generate electricity (factories). Thermal). Mechanical energy generated by the change in pressure in the reaction medium (with fixed volume) has been widely used in internal combustion engine devices.

– The process of redox reaction of metals such as Copper (Cu), Lead (Pb), Zinc (Zn), Nickel (Ni), Cadmium (Cd), Lithium (Li) ... all generate electric current. The electricity generated from this process has been used in the production of batteries and electrochemical batteries.

– Chain reactions of radioactive elements such as Uranium-235 or Plutonium-239 under specific conditions will generate heat. Heat energy generated from this process is converted into mechanical energy and electricity for human consumption, in fact, all nuclear power plants in the world operate on this principle.

– The process of chemical reaction between H2 and O2 under specific conditions will generate heat or electricity. The large heat generated directly from this process has been applied in metal cutting technology or as fuel for rocket engines. The electricity generated from this chemical reaction under specific conditions has been applied to electric vehicles or used directly for production and living activities through a device called fuel cells. Thus, with this ability, H2 is considered as an energy source that is and will be an alternative to fossil energy in the future.

II. Energy H2

Overview of H2

Hydrogen - H2 is a common chemical element, constituting up to 90% of the matter of the universe and accounting for 75% by weight, existing mainly in the form of compounds with other common chemical elements such as forming oxygen. into water (H2O), with carbon into organic compounds and life all over the earth. H2 gas is colorless, odorless, light and highly flammable and therefore does not exist as a pure molecule under normal conditions. H2 is very easy to chemically react with other chemical elements, especially oxygen, and at the same time produces energy in the form of large heat or electricity through the following chemical reaction:

2H2 + O2 → 2H2O + Energy

Hydrogen is a secondary energy source, i.e. it is not available for direct extraction but must be generated from a primary primary source such as water or other hydrocarbon compounds.

Production of H2

There are two basic methods for large-scale production of H2, including:

a) Thermalization of hydrocarbon fuels such as methane, oil, biofuels, gasified biomass, gasified coal and natural gas. In the world today, about 90% of H2 is produced by this technology. This method has been applied and developed into three types of technologies, including:
– Natural gas steam reforming technology to separate H2 from natural gas whose main composition is methane CH4 (CH4 + 2H2O → CO2 + 4H2), this process requires heat energy. and suitable catalyst. This is the current common industrial method for hydrogen production. However, this method still generates CO2 and is not applied to create an energy source, but only to provide raw materials for the chemical, fertilizer, petroleum refining industries, etc.

– Gasification heavy hydrocarbon (Gasification heavy hydrocarbon) technology includes petroleum and coal, this process is carried out at a temperature of about 1,400 oC in the absence of oxygen to produce H2 and CO gas, CO continues to react react with steam and catalyst to convert to CO2 and H2. This method is quite popular because it takes advantage of the existing infrastructure and equipment of the petrochemical industry. However, this technology still produces CO2 which causes greenhouse effect and is unsustainable because the fuel source will be exhausted.

– Biomass gasification and pyrolysis technology to produce hydrogen by converting biomass into a gas through high-temperature gasification that produces water vapor. The steam is condensed in the pyrolysis oils and thermochemically produced to produce H2. This process typically produces H2 yields in the range of 12-17% of the biomass's hydrogen weight. The raw materials for this method can include wood chips, plant biomass, agricultural and municipal waste, etc. This method of H2 production still requires a large amount of energy, but is still considered as a source of energy. renewable and sustainable energy sources.

b) Water electrolysis method (Electrolysis) by using electric current to split water into H2 and O2 gas. The process consists of two reactions occurring at the two electrodes and H2 is generated at the negative electrode and O2 is produced at the positive electrode (2H2O + Electricity → 2H2 + O2). Currently, there are 3 popular electrolysis technologies including:

– Electrolysis technology is usually conducted with an electrolyte that is water or alkaline solution. The two parts of the negative electrode and the positive electrode are separated by an ion diaphragm to avoid mixing the two gases produced.

Water electrolysis technology at a high temperature of about 800-1,000oC makes the electrolysis process take place with higher efficiency, the heat supplied is mainly used from solar energy or excess heat from the process. other suitable industrial energy processes.

Water electrolysis technology with electricity from renewable energy sources such as solar power, wind power, integrated hydroelectricity. This system and technology is considered clean and sustainable and is the development trend of the future.

In addition, in nature some algae and bacteria can produce H2 as a by-product of their metabolism. However, to master these processes and develop into industrial scale H2 production is still being studied by researchers.

Demand for H2

Hydrogen is mainly used in industry and energy:

In industry, H2 is used as a raw material for chemical industries such as ammonia, methanol, oil refining, fertilizer production, metallurgy industry, cosmetics, semiconductors...

In energy, H2 is a potential fuel source with many favorable environmental and economic advantages. When used as a fuel, H2 can be burned directly in internal combustion engines, similar to today's popular gasoline-powered vehicles. H2 can also replace natural gas to provide energy for daily civil needs such as cooking, heating, lighting, etc. In particular, H2 has been used as a fuel for rockets in the aerospace industry. headquarters and defense. H2 can also be used as an energy source for fuel cell systems, thanks to the electrochemical process to generate electricity.

Advantages of H2 . energy

H2 energy is considered a form of chemical energy with many advantages because the product of this process is only pure water and energy without any harmful waste to the environment, no CO2 emissions. global climate change, is an almost inexhaustible or renewable source of energy.

– H2 energy contributes to ensuring energy security, can be produced from many different available sources, especially from renewable energy sources such as wind and solar, without depending on other sources. sources imported from abroad. With the role of "storage" of energy, H2 makes the distribution and use of energy convenient and can be stored for a long time, especially H2 produced from renewable energy is considered a transport material. move renewable energy to areas with no advantage or store it for use during periods of the night, with no wind…

– H2 energy can solve many different problems such as zero carbon emissions in some industries that are difficult to reduce such as transportation, chemicals, metallurgy, helping to improve air quality and public health. copper.

– H2 energy can be produced, stored and transported in the current natural gas (LNG) transportation infrastructure, which can be used in the form of conversion into electricity or gas such as CH4 for other needs. such as living, industrial, livestock or as fuel for means of transport.

– In terms of safety, the low density and fast diffusion allow H2 to escape quickly into the atmosphere if a leak occurs. Especially with its non-toxic and non-corrosive nature, if H2 is released, it will evaporate almost completely and leave no harm.

– Equipment using H2 fuel is a fuel cell that has the characteristics of running quietly, causing no noise and vibration like an internal combustion engine. Fuel cells are much more efficient than internal combustion engines and are more energy efficient. According to the assessment, fuel cells will be a promising energy source, playing a key role in the hydrogen economy in the future.

Challenges in developing H2 . energy

Besides the advantages of H2 energy mentioned above, with the characteristics and requirements of the processes of producing, storing, transporting, distributing and using H2 energy, there are still some challenges to make this form of energy This has only been developed in developed countries, the challenges include:

– With the characteristic of light, volatile, so H2 must be stored in high pressure compressed air cylinders or as liquefied gas or adsorbed in absorbent materials. Currently, technologies and equipment for H2 storage are still limited in capacity and can only be met on a small scale.

– Although the source of raw materials for H2 production is almost endless, the process of producing H2 from electrolysis is quite expensive. Currently, H2 energy is only applied on a small scale in many countries. developed and currently scientists are continuing to research to reduce the cost of this technology.

– Currently, the production of H2 by water electrolysis still uses electricity mainly produced from fossil fuels (coal, oil, gas), so it is essentially a renewable energy and does not cause harm. The impact on the environment has not been completely resolved, especially electricity from renewable energy (wind, solar) is still quite expensive compared to electricity from fossil fuels. It is forecasted that by 2030, the cost of renewable energy production will continue to decrease by about 30%, then the H2 production system from renewable energy will have the opportunity to develop explosively.

– Under natural conditions, H2 is very short-lived, volatile and flammable. Therefore, transportation, storage and distribution to the end users face many difficulties in terms of preventing leakage and ensuring safety. Currently, H2 is mainly transported through pipelines or on waterways and road vehicles in a liquefied or compressed state in pressure vessels.

III. DEVELOPMENT AND USE OF H2 ENERGY IN THE WORLD AND VIETNAM

General trend

With the advantages and development potential of H2 energy, it is attracting strong attention from governments and businesses as a new generation energy. The 2nd Hydrogen Energy Ministerial Conference in Tokyo on September 2019 showed the progress of hydrogen-related technologies in many countries around the world, especially developed countries. The fact that the Conference attracted senior leaders and leading energy experts from more than 30 countries shows a global interest in sharing information on policies to increase the use of Hydrogen globally. The interest in this energy source is not only aimed at the goals of energy security, but also the interest of countries and businesses to the goals of reducing greenhouse gas emissions, converting energy into energy. lasting.

Through the information from energy forums over the past time, it can be seen that the commitment of many governments in policies to promote the use of H2 energy, the pioneering of scientists, businesses in the world. research and implement projects to develop industrial H2 production equipment, H2 energy storage, transportation, distribution and use systems

Currently, about 90% of H2 is produced mainly from petroleum and natural gas, which means that there will still be greenhouse gas emissions of CO2 and is not an encouraging trend. develop. Therefore, the application of renewable energy technology to electrolyze water to produce H2 is a model that has been successfully researched and tested in many countries. This solution is continuing to be encouraged by the governments of other countries, scientists and businesses are interested in developing, perfecting and improving the scale, capacity and cost reduction..

The development of storage, transportation and distribution infrastructure is currently very limited, which has hindered the widespread application of H2 energy in many countries. The price of H2 to the consumer depends heavily on the number of refueling stations, how often it is used, and how much H2 is supplied per day. Addressing this issue requires a master plan and coordination mechanism between governments, industries and domestic and international investors.

According to the International Energy Agency (IEA) assessment, to develop H2 energy, it is necessary to implement 4 immediate solutions including:

1) Encourage and create industries and industrial parks that are pioneers in the conversion of using H2 energy

2) Transform, build infrastructure for more competitive H2 fuel storage, transport, and distribution

3) Deploying projects on supply, transportation, international trade on H2

4) Strengthen international cooperation, share knowledge, experience, best practices to disseminate, standardize and promote commercialization.

In the long-term view, the IEA also makes 6 recommendations including:

1) Determine long-term goals for H2 energy in the national energy development strategy, including both production and use targets in energy-using sectors and industries.

2) Encourage research, development, production and commercialization of renewable, clean and low-carbon H2 fuels

3) Having policies and mechanisms for sharing and minimizing risks for investment, production and development projects related to H2 energy for investors

4) Support research and development (R&D) to reduce the cost of H2 energy from production, storage, transportation, distribution, and application equipment and products

5) Create a strong enough legal framework for management, attractive enough support and promotion mechanisms to attract investors' attention

6) International cooperation, strengthen the exchange of information on techniques, technologies and standards in order to connect and strengthen the support of investors to develop the linked market.

2. Joint Statement at the 2nd Hydrogen Energy Ministerial Conference in Tokyo (Tokyo Declaration)

On the basis that all the participants of the Conference were aware of the importance of H2 energy from how to scale up, develop a roadmap, long-term strategy and define policies and action plans. to change. The Tokyo Declaration made the following four statements:

i) Technology cooperation to harmonize and agree on common regulations and standards between countries and economies.

ii) Promote information sharing, research cooperation to develop safe and effective H2 supply chain infrastructure.

iii) Research and evaluate the potential application of H2 in industries and fields, including the reduction of CO2 and other pollutants.

iv) Communication, education and dissemination of H2 energy to the community.

3. H2 energy use in some economies

The application of H2 energy has been developed by countries mainly in the transport sector, specifically in a 2017 report by the IEA, it was reported:

– For personal electric vehicles using fuel cells (H2): Globally, over 2 million personal electric vehicles using fuel cells of all kinds were sold in 2016 and increased by 60% compared to 2015 Japan plans to produce 3,000 fuel cell electric vehicles in 2017, 40,000 vehicles in 2020, 200,000 vehicles in 2025 and 800,000 vehicles in 2040. In California, in April 2017 alone, there were over 1,600 vehicles. registered fuel cell electric vehicles, an increase of 1,300 vehicles compared to the previous month. There are only 75 in Denmark and 49 in the UK with fuel cell electric vehicles on the road.

– For public electric vehicles using fuel cells (mainly buses): In Europe, in 2016, after 6 years of testing, 56 buses were operated, and in California, 12 buses have been operated since 2016. 2013. In Guangdong, China, the two cities of Foshan and Yunfu in the province have planned to order the production of 300 fuel cell buses with an investment of 17 million USD. Korea aims to replace about 26,000 current CNG buses with fuel cell buses. By 2017, the EU had 139 buses and the UK had 42 fuel cell buses.

– For heavy equipment and vehicles: By October 2016, the United States had sold 11,600 fuel cell lifting devices, which are very popular in retail businesses such as Walmart or in France retailer Carrefour also owns 150 fuel cell lifters. For heavy transport vehicles have also been deployed in Norway (4 units), Switzerland (1 unit) and the Netherlands.

– Other means of transport: In 2002, the first electric passenger train using fuel cells was developed in Quebec, Canada. To date, there have been a number of contracts and agreements to cooperate in research and testing of fuel cell electric train systems in Europe, Germany and China. In 2006, fuel cell ships were also tested for the first time in Japan, followed by a number of projects to develop and demonstrate H2-powered ships in France, Norway, Switzerland, Italy… The IEA itself has set a mission to promote the development of marine H2 energy for research and demonstration. Unmanned aerial vehicles and aircraft have also been studied by a number of countries such as France, Germany, the United States and China for this type of energy.

In addition, H2 energy applications are also being developed for thermal (heating) needs, as Japan set a target of connecting 1.4 million cogeneration energy systems by 2020, and reaching about approx. 5.3 million by 2030 at industrial and commercial facilities and towards gradually replacing the natural gas pipeline system with H2 gas pipelines in the future. Other countries such as the United Kingdom, Australia have all had studies and plans to replace heating fuel sources from natural gas to H2.

Thus, although H2 energy has not been widely used because of its high price and not suitable in the absence of infrastructure to support it, however, researchers still consider this to be an invaluable source of energy. renewable, and is an energy source that plays a key role in replacing fossil fuels, does not pollute the environment and is the energy source of the future.