250ml of concentrated sulphuric acid (98%) is placed in the outer chamber ‘D’ and the COGen assembled.
Opening the screw ‘E’ allows the formic acid to drip into the concentrated sulphuric acid. Copious amounts of carbon monoxide are released and exit the chamber through vent holes in the lid ‘H’.
The Video shows the COGen being armed and placed in a small car. The carbon monoxide concentration in the car was continuously sampled with a probe positioned near the head of the mannequin. The graph (Fig 6.8) shows the measured concentration in ppm, plotted over the first 30 minutes. Lethal concentrations were reached a few minutes after switching on the generator. A peak level of ~3% CO was recorded.
Sourcing the Acids
Concentrated sulphuric acid (98%) can be purchased from chemical suppliers or at hardware stores where it is sold as a drain cleaner. Concentrated laboratory sulphuric acid is an oily clear liquid, whereas the drain-cleaner sulphuric acid can be dark brown in colour because of additives, but this does not effect the generator’s operation.
Formic acid is available from chemical supply companies. Home hobbyists use formic acid in tanning or bee-keeping. Formic acid can also be purchased online through chemical supply websites.
Oxalic acid is used as rust and stain cleaner and can be purchased from hardware stores.
