Evaluation of carbonyl compound emissions from a non-road machinery diesel engine fueled with a methanol/diesel blend

Abstract

The carbonyl emissions from a non-road machinery diesel engine running on diesel fuel (DF) or methanol-diesel blend fuel (M/DF) were investigated under a series of steady-state operating conditions. Carbonyl compounds (CBCs) were collected from the diluted exhaust, employing 2,4-dinitrophenylhydrazine-coated silica gel cartridges, and analyzed using a high-performance liquid chromatography system with a photodiode array detector. The results indicate that formaldehyde and acetaldehyde are the most abundant carbonyls, followed by acrolein, acetone, propionaldehyde and crotonaldehyde. Each of these compounds exhibit a consistent reduction with increases in the engine load. The M/DF produces much more formaldehyde, acetaldehyde, acrolein, acetone and crotonaldehyde than the DF at low loads, while there are marginal differences in the emission levels of these carbonyls between M/DF and DF at medium and high loads. The use of M/DF decreases propionaldehyde emissions at all test conditions. Compared with the results obtained using DF, the total CBC emissions increase by 45.3% and the ozone formation potential (OFP) increases by 57.0% when burning M/DF at low engine loads. In general, M/DF increases both OFP and total CBC emissions to a greater extent than biodiesel-blend fuel but to a lesser degree than ethanol- or butanol-containing blends.