Influence of waste oil-biodiesel on toxic pollutants from marine engine coupled with emission reduction measures at various loads

Abstract

Maritime transport has widely been used throughout the record history, and yet is the major source of toxic pollutants to the atmosphere. Bearing this in mind, the effect of biodiesel on regulated and unregulated toxic pollutants with high-efficiency post-treatment (HePT) device from marine diesel engine were investigated at various engine loads. Organic carbon (OC), elemental carbon (EC), gaseous emissions, soot particle number and size distributions, polycyclic aromatic hydrocarbons (PAHs), n-alkanes species, trace metals and fatty acid methyl esters, were quantified and analyzed. The results showed that all the regulated gaseous emissions were within the standard limits, except for CO emission at idle mode. This was inconsistent to the result found with unregulated emissions. For unregulated emission factors (EFs), PM2.5 species were dominated by OC, and similar proportion was observed with soot-EC using HePT device fueled with B25 and B50. The B25 and B50 EFs of total-PAHs were decreased from 11.7% to 54.8% compared to B0 at all engine loads. The dominant PAHs and 2- to 5-ring species, were decreased substantially when using B50. Both fuel blends recorded a definite outline by dodecane, tetradecane and hexadecane at low load, whereas ∼68.3% average reduction was observed with these n-alkane species at high load. The major metals present in lubrication oil were Ca, Zn, P, Mg, V, Si and Fe. These metals were 3 times higher than B0 metals. The accumulation mode particles rise with the load increase and the peaks gradually move to large particle size.