Hydrogen is one of the most abundant elements in the universe and has been used for a variety of purposes for centuries since the late 1600s. It is an energy-rich and versatile fuel, and with its potential for clean energy production, energy storage, and bridging hard-to-abate industries with renewable energy; hydrogen has become a major focus of research and development. In recent years, there has been a growing interest in two types of hydrogen: green hydrogen and blue hydrogen. In this article, we will explore the differences between "green hydrogen" vs "blue hydrogen", and their respective advantages and disadvantages.
Introduction to Hydrogen
Hydrogen is a colourless, odourless, and tasteless gas with a high energy density. One kilogram of Hydrogen carries an equivalent energy of 1 gallon of gasoline (2.767 kilograms equivalent. This makes it an ideal energy carrier. Hydrogen can be used to power vehicles, generate electricity, and produce heat. It can also be used to create synthetic fuels and chemicals, such as methanol, methane, aniline and even plastics. Hydrogen can be produced from a variety of sources, including natural gas, coal, biomass, and water. The most common methods of producing hydrogen are steam reforming of natural gas (methane) (SMR) and Coal gasification which uses heat to produce hydrogen and carbon dioxide from methane and coal respectively. Unfortunately, these processes are not efficient and produce a large amount of carbon dioxide, which is a greenhouse gas. In 2020 alone SMR and Coal gasification together emitted 900 million tonnes of carbon dioxide into the atmosphere and this value is equal to the collective emissions of a few industrial nations. Therefore alternative production processes are in demand, as such Green Hydrogen and Blue Hydrogen are under the microscope of leaders in the Hydrogen Economy.
What is Green Hydrogen?
Green hydrogen is a form of hydrogen produced through the electrolysis of water using renewable electricity. This process uses renewable electricity to separate water molecules into Hydrogen and Oxygen. This process is clean, and efficient, and produces no emissions of Carbon Dioxide. All the products of this electrochemical reaction are useful and the overall reaction can be considered 100% atom efficient according to the Green Chemistry principles. It is considered to be the most sustainable and environmentally friendly form of hydrogen production.
The success of green hydrogen depends on the availability of excess electricity in renewable energy grids due to the intermittency of its sources and the fluctuating demand by end users. This makes green hydrogen a viable option for countries that have access to renewable energy sources. The cost of green hydrogen production is presently higher than traditional methods of hydrogen production. However, as the technology continues to advance and more companies & nations begin adopting green hydrogen, it is expected that the cost of Green Hydrogen will decrease over time. In the present scenario, green hydrogen costs are in the range of 2.5 - 6 USD per kilogram. However, with the rapid progress of investments, innovations and implementations in the Green Hydrogen sector, it is predicted that the cost will come down to 1 - 3 USD per kilogram by 2050.
What is blue hydrogen?
Blue hydrogen is a form of hydrogen produced from natural gas. This process involves the steam reforming of natural gas to produce hydrogen and carbon dioxide as it is in the grey hydrogen concept (for the colour code of hydrogen please refer to this page). However, in the blue hydrogen concept, carbon dioxide is captured, stored, and utilized. This process is more efficient and climate-friendly than traditional hydrogen production methods (SMR and Coal Gasification) and is considered to be a promising solution to the heavy climate impact of the present hydrogen economy. The main advantage of the blue hydrogen option is that it can be used to reduce emissions while still using the existing infrastructure of the present hydrogen industry. This makes blue hydrogen more attractive to countries that are heavily invested in the natural gas-based hydrogen industry.
Is compliance with existing infrastructure enough to justify blue hydrogen over green hydrogen? If it is the case, why are more than 30 nations including European Union investing heavily in Green Hydrogen? Why African nations are targeting to capture 10% of the Green Hydrogen market share by 2050?
Green Vs blue hydrogen (Comparison and Pros & Cons of each option)
Green hydrogen and blue hydrogen have several key differences that make them attractive to different markets. Green hydrogen is produced through the electrolysis of water, a process that is clean, efficient, and produces no emissions. Blue hydrogen is produced through the steam reforming of natural gas with embedded carbon capture, utilization and storage (CCUS). When considering the primary facts about the case of Green Hydrogen vs Blue hydrogen, Green hydrogen is most attractive to countries that have access to renewable energy sources, as it is the most environmentally friendly form of hydrogen production while Blue hydrogen is more attractive to countries that are heavily invested in natural gas infrastructure, as it can be used to reduce emissions while still using existing infrastructure.