Status of application
Hydrogen has gained significant interest worldwide for its potential to displace fossil fuels and abate CO2 emissions when it is produced from renewable energy. However, today hydrogen is mainly produced from fossil fuels for industrial purposes. In 2018, global demand for hydrogen was roughly 120 Mt corresponding to 14.4 EJ. This makes up around 4% of final energy and non-energy use in the world. Demand has been increasing since 1980 and has grown more than 30% from 2010 to 2018 (see figure below).
Figure 87. Global annual demand for hydrogen. Source: IEA based on (IRENA, 2019)
The majority of hydrogen consumption today is produced and used on-site in industries. About 70-80% of the hydrogen production is made as the primary product while the remaining part is produced as a byproduct from other industrial processes. The main demand for hydrogen comes from the refining sector (32% in 2018) and ammonia production for fertilizers (27%). Besides these, hydrogen is also consumed for methanol production (8%), iron and steel (3%) and other industrial applications such as semiconductors, propellant fuels, glass production, hydrogenations of fats, cooling of generators and more. (IRENA, 2019) (IRENA, 2018)
Technology development and maturity
Historically, hydrogen has been produced from fossil fuels through thermochemical reactions. In 2018, 95% of global hydrogen production was natural gas and coal based (majority from natural gas) while less than 5% was produced from electrolysis. (IRENA, 2019) The main deployment of electrolysis today comes from the chlorine production where hydrogen is produced as a byproduct. Globally, hydrogen production from renewables is only in its infancy however, the number of projects is increasing rapidly for research and development purposes.
The thermochemical production process depends on the fuel. Hydrogen from natural gas is produced through the steam methane reforming reaction (SMR). From coal it can be produced by gasification of coal. Hydrogen can also be produced from gasification of biomass. However, it is not a very common.
Hydrogen production technologies include:
• Natural gas – steam methane reforming (SMR)
• Coal – Coal gasification
• Biomass – Biomass gasification or biomass-derived liquid reforming
• Water electrolysis
• Direct Solar Water Splitting processes
• Biological processes (DOE, 2020)
CO2-neutral hydrogen production
Hydrogen has the potential to substitute fossil fuels and has therefore achieved substantial political focus in the recent years primarily driven by a wish to mitigate climate change. For instance, Japan and South Korea have set ambitions targets for the deployment of hydrogen production and power to X technologies. This potential can only be redeemed when hydrogen is produced in a CO2-neutral way. The two main CO2-neutral ways of producing CO2 -neutral hydrogen includes electrolysis-based production from renewable electricity or blue hydrogen production.
Blue hydrogen production covers fossil fuel-based production with carbon capture and storage (CCS) such that net CO2 emission is close to zero.
Electrolysis
The electrolysis technology is an overall process where water is split into hydrogen and oxygen. There are three main technologies with different levels of maturity:
• Alkaline electrolysis
• PEM electrolysis
• SOEC electrolysis
Alkaline electrolysis is a mature and commercial technology. It has been used since the 1920s, especially for hydrogen production in the fertilizer industry and the chlorine industry. A range of alkaline electrolysers are flexibly operated from 10% load to full design capacity. Several alkaline electrolysers with capacities of over 100 MW of electricity were previously established in countries with large hydropower resources (Canada, Egypt, India and Norway). Today, most of these today are outcompeted by hydrogen production based on fossil fuels. Alkaline electrolysis is characterized by relatively low capital costs compared to other electrolysis technologies, e.g. due to the fact that common and inexpensive materials are used.
PEM electrolysis was introduced in the 1960s by General Electric to overcome certain disadvantages of alkaline electrolysers. PEM electrolysers use pure water as an electrolyte solution, thus avoiding the recovery and recycling of potassium hydroxide. On the other hand, the water needs to be purified before being able to be used. They can be relatively small, making them potentially more interesting for specific purposes. They are capable of producing highly compressed hydrogen for decentralized production and storage at service stations (30-60 bar without an additional compressor and up to 100-200 bar in some systems compared to 1–30 bar for alkaline electrolysers).
Their operating range can go from zero load to 160% of the design capacity. However, they need expensive electrode catalysts (platinum, iridium) and membrane materials, and their service life is currently shorter than for alkaline electrolyzers. They have higher costs and are less common.
SOECs are the least developed electrolysis technology. SOEC uses ceramic materials as electrolyte and therefore has low material costs. They operate at high temperatures and with a high degree of efficiency. Since steam is used for the electrolysis, a heat source is needed, which contributes to high electricity efficiency.
(IEA, 2020)
Figure 88. Timeline of power-to-hydrogen projects by electrolyser technology and project scale. Source: (IRENA, 2019)
The deployment of electrolysis is limited but several countries have developed strategies for how hydrogen, carbon capture and storage and PtX can contribute to the green transition and business development. This includes EU, Japan, South Korea, France, Germany, Norway, the Netherlands and more.
Future hydrogen consumption
Besides the significant global demand for hydrogen for traditional purposes (mainly refining and fertilisers), a new hydrogen demand is expected to arise due to the need for alternative fuels to mitigate climate change. It is essential that this future demand for hydrogen is supplied from sustainable and renewable sources.
Hydrogen has potential to be used either directly in the transport sector or to be applied in fuel cell vehicles.
Especially in the hard-to-transit sectors like heavy duty vehicles or long-distance busses, hydrogen and fuel cells could play a role if it is cost effective compared to other green alternatives. By 2030, Japan aims to produce 300,000 tons of hydrogen annually (corresponding to 36 PJ) and they have a target to increase the number of fuel cell vehicles to a total of 800,000.
Moreover, hydrogen could also be used as input to produce a variety of other products through the power to X technologies. Power to X covers a range of technologies where renewable hydrogen is used in combination with for instance CO2 and nitrogen to produce gaseous or liquid fuels such as methane, methanol, ammonia, syndiesel and sustainable aviation fuel.
The key to low hydrogen production costs from electrolysis is low electricity prices from renewable resources.
Perspectives for further studies Further studies could include:
• Mapping existing hydrogen consumption in Vietnam
• Technology and economic data for hydrogen production capacity in Vietnam including with focus on electrolysis technology
• Perspectives for hydrogen to substitute fossil fuels in Vietnam
• Potentials and costs of Power to X production in Vietnam References
DOE. (2020). Hydrogen production processes. Washington: US Department of Energy.
IEA. (2020). The future of hydrogen. Paris: International Energy Agency.
IRENA. (2018). Hydrogen from renewable power. Technology outlook for the energy transition. Abu Dhabi:
International Renewable Energy Agency.
IRENA. (2019). Hydrogen - A renewable energy perspective. Abu Dhabi: International Renewable Energy Agency.