Toyota Motor Corporation has developed the world’s first general-purpose hydrogen burner for industrial use in collaboration with Chugai Ro Co., Ltd. The burner is in use today at the forging line in Toyota’s Honsha Plant.
In conventional hydrogen burners, hydrogen reacts rapidly with oxygen, leading to a high flame temperature and environmentally hazardous NOx emissions.
On account of this, the practical use of hydrogen burners has proved challenging. The newly developed burners incorporate two new structures that enable hydrogen to combust more slowly.
The new burners also have zero CO2 emissions and greatly reduced NOx emissions – lower than equivalent natural gas burners – resulting in outstanding environmental performance.
If hydrogen and oxygen are in a fully mixed state when ignited, the mixture burns violently with a high flame temperature.
In the newly developed burner, hydrogen and oxygen flow side-by-side and are ignited without being fully mixed, leading to slower combustion and a lower flame temperature.
If the fuel mixture contains a high concentration of oxygen at the time of ignition, combustion is violent with a high flame temperature.
To prevent this, small holes are opened in the pipes that supply hydrogen to the burner, enabling small volumes of hydrogen and oxygen to pre-combust.
Oxygen concentrations are consequently reduced to an optimal 19-percent level for main combustion, resulting in a lower flame temperature.
The new technology will enable 1,000 large-scale natural gas burners to be replaced by hydrogen burners at its plants across Japan.
Toyota is planning to install hydrogen burners gradually at its other plants, and other companies in the Toyota Group are also considering installation.