Abstract: Although there are quite a lot of methods for formaldehyde measurement, it is difficult to collect effectively the formaldehyde emission from the engine exhaust gas. Based on the fact that formaldehyde can dissolve in water at any proportion, a formaldehyde collection equipment was developed by water dissolution technique. The formaldehyde concentration in the engine exhaust emissions was measured by a spectrophotometer, and its feasibility was validated by tests. The formaldehyde emission characteristics from an engine fuelled by gasolinemethanol blends with different blending proportions under different working conditions were investigaled by the developed equipment and suggested technique. The results show that the formaldehyde emission is direct proportional to the methanol fraction in the fuel blend, and in inverse proportion with the engine speed and load.

Key words: power and machinery engineering, engine, formaldehyde emission, spectrophotometer