REUTERS AND CHEMISTRY DEPARTMENT, COPENHAGEN UNIVERSITY - Belching factories are a leading cause of air pollution world-wide.
And with EU emission rules being tightened, European businesses face a tough task to clean up their act.
"This is the control unit for the emissions control system. Here on my right we have the ozone generators and we have the system for controlling the lamps here on my left. There are also some pumps that are moving water through the scrubber."
Johnson conducted six years of trials in these aluminium boxes on top of the Jysk Miljoerens industrial plant in Aarhus.
The plant, which recycles oil taken from bilge water in ships, faced years of complaints from neighbours over the smell it produced.
But now, they say, the air quality has improved
Johnson's mechanical unit, co-devised by technological firm Infuser, speeds up natural atmospheric processes to clean the air within seconds, ridding it of pollutants and smells.
"The basic idea is that we need to accelerate the natural processes that remove pollution and we do that by adding some ozone, we add some artificial sunlight, some UV lamps and we start to oxidise the pollution and when these molecules become oxidised, they get stickier... they make a little droplet and then we put an electrical charge onto that droplet and then we use that charge to drag it onto a filter plate."
With no mechanical filter necessary, energy is saved and large quantities of air can be treated.
Johnson says the units are easy and inexpensive to maintain and can be retro-fitted inside existing air cleaning units.
He says that in factories of the future, they could potentially replace chimneys.
In conjunction with other pollution control systems Johnson believes the popularity of his device in Aarhus can be replicated in industrial areas around the world.