Back to Articles
Share this Article

Fleet owners and operators can benefit from this new hydrogen technology which delivers tangible emissions' reduction as well as better fuel economy.

"Carbon cleaning" or "HHO carbon cleaning" is the process of removal of carbon deposits from the internal surfaces of the engine and the exhaust tract components, using a mixture of Hydrogen and Oxygen.

Briefly, the process of HHO carbon cleaning consists of the following steps:

  • Production of HHO gas by electrolysis;
  • Pre-mixing of HHO gas with the ambient air in the engine air intake;
  • Running the engine on HHO-air-fuel mix for a predefined period of time;
  • Verification of the results of HHO carbon cleaning;


The mix of Hydrogen and Oxygen, also known as oxy-hydrogen gas, hydroxy gas, HHO gas, or Brown’s gas, is produced by the electrolysis of water. The electrolyser uses the mains electrical power, or the power of a car battery, to split water molecules (H2O) into Hydrogen (H) and Oxygen (O).

HHO gas pre-mix

The HHO gas is introduced into the engine by pre-mixing it with the ambient air in the air intake manifold, while the engine is running.

The negative air pressure created by the engine helps deliver the HHO gas into the engine. Due to the turbulence in the air intake, the HHO gas is pre-mixed with the air, just before the combustion.

Carbon-cleaning process

The process of HHO carbon cleaning itself can take between 30 minutes and 1.5 hours, depending on such factors as engine displacement and the degree of carbon deposits on the engine and exhaust tract components. The duration of HHO carbon cleaning session is determined by the mechanic on the basis of the recommendations of the HHO machine manufacturer.

Once the HHO carbon cleaning process is finished, it is recommended to take the car for a drive on a motorway for at least 15 minutes, to ‘flash’ the remaining carbon deposits from the exhaust.

Results verification

The effectiveness of the HHO carbon cleaning procedure is verified by measuring certain vehicle parameters before and after the process, for example:

  • Exhaust emissions (opacity, NOx, CO, CO2, etc.);
  • Counter-pressure at the DPF (diesel particulate filter);
  • Soot accumulation in the DPF;
  • Degree of movement of the EGR (exhaust gas recirculation) valve;

In summary, fleet owners and operators should investigate the possibilities to deploy hydrogen premix technology, as they can immediately benefit from this new eco technology which delivers tangible emissions' reduction as well as better fuel economy.

Comments ({{count}})
Replies: {{comment.comments_count}}
There are currently no comments. Be the first to comment on this article
Load more +

Want to leave a Comment? Register now.

Are you sure you wish to delete this comment?