Research Study, Energy News, ET EnergyWorld
According to a new study published in the journal Energy Science and Engineering, the carbon footprint for creating blue hydrogen is more than 20% greater than using natural gas or coal directly for heating, or around 60%. greater than the use of diesel for heating. .
Blue hydrogen begins by converting methane to hydrogen and carbon dioxide (CO2) using heat, steam and pressure, or gray hydrogen, but goes a step further to capture some of the CO2 . Once the byproduct CO2 and other impurities are sequestered, it becomes blue hydrogen, according to the US Department of Energy.
The process of making blue hydrogen requires a large amount of energy, which is typically supplied by burning more natural gas, according to researchers at Cornell and Stanford universities.
“In the past, no effort was made to capture the CO2 byproduct of gray hydrogen, and greenhouse gas emissions have been enormous,” said Robert Howarth, professor of ecology and environmental biology at Cornell.
“Now the industry is promoting blue hydrogen as a solution, an approach that still uses methane from natural gas, while trying to capture the by-product CO2. Unfortunately, emissions are still very high,” he said. added.
Methane is a powerful greenhouse gas, Howarth said. It is over 100 times more potent as an atmospheric warming agent than CO2 when it is first emitted. The recent report of the United Nations Intergovernmental Panel on Climate Change shows that cumulatively to date over the past century, methane has contributed about two-thirds as much to global warming as CO2, has he declares.
Emissions of blue hydrogen are lower than those of gray hydrogen, but only about 9 to 12%.
Blue hydrogen as a strategy only works to the extent that it is possible to store long-term CO2 indefinitely in the future without leaking into the atmosphere. On the other hand, an environmentally friendly “green” hydrogen exists, but it remains a small sector and it has not been marketed.
Green hydrogen is obtained when water goes through electrolysis (with electricity supplied by solar, wind or hydroelectric power) and the water is separated into hydrogen and oxygen.