Emissions of PCDD/Fs, PCBs, and PAHs from a Modern Diesel Engine Equipped with Catalyzed Emission Control Systems

Abstract

Exhaust emissions of 17 2,3,7,8-substituted chlorinated dibenzo-p-dioxin/furan (CDD/F) congeners, tetra-octa CDD/F homologues, 12 2005 WHO chlorinated biphenyls (CB) congeners, mono-nona CB homologues, and 19 polycyclic aromatic hydrocarbons (PAHs) from a model year 2008 Cummins ISB engine were investigated. Testing included configurations composed of different combinations of aftertreatment including a diesel oxidation catalyst (DOC), catalyzed diesel particulate filter (CDPF), copper zeolite urea selective catalytic reduction (SCR), iron zeolite SCR, and ammonia slip catalyst. Results were compared to a baseline engine out configuration. Testing included the use of fuel that contained the maximum expected chlorine (Cl) concentration of U.S. highway diesel fuel and a Cl level 1.5 orders of magnitude above. Results indicate there is no risk for an increase in polychlorinated dibenzo-p-dioxin/furan and polychlorinated biphenyl emissions from modern diesel engines with catalyzed aftertreatment when compared to engine out emissions for configurations tested in this program. These results, along with PAH results, compare well with similar results from modern diesel engines in the literature. The results further indicate that polychlorinated dibenzo-p-dioxin/furan emissions from modern diesel engines both with and without aftertreatment are below historical values reported in the literature as well as the current inventory value.

Effects of Selective Catalytic Reduction on the Emissions of Persistent Organic Pollutants from a Heavy-Duty Diesel Engine

“…When the two results were compared, the PCDFs/PCDD ratio of the after SCR was larger implying that more PCDFs were formed as shown in Table 2. However, our results were contrary to previous studies which have reported a reduction of PCDD/Fs after the engine was retrofitted with a SCR (Hovemann et al, 2010;Laroo et al, 2011). Before SCR After SCR…”

“…1. This is similar to other reported results from previous studies (Laroo et al, 2011;Liu et al, 2011;Laroo et al, 2013).…”

“…That is because the heavy diesel engine, a 2008 MY 6.7 L Cummins ISB, used in Laroo et al (2011) is more modern than the engine used in our study, and its PCDD/F emission factor (1.89 pg I-TEQ L -1…”

“…Several studies have studied ways to reduce these POP emissions e.g., by testing biofuels and biofuels-diesel blends and water containing alcohol blends with positive results in terms of POP emission reduction (Mwangi et al, 2015a, b;Tsai et al, 2015Tsai et al, , 2016. Laroo et al (2011) studied the PCDD/F and PCB emissions under steady state and found the emission factors of CuZ-SCR HT, CuZ-SCR LT (A 20 Hp difference in power between HT and LT), and FeZ-SCR to be 1.6 pg I-TEQ L , and 2.78 pg I-TEQ L -1 and 0.04 pg WHO-TEQ L -1 , respectively. They also concluded that PAH, PCDD/F and PCB emissions from modern HDDEs equipped with DOCs, DPFs and SCRs are significantly lower compared to legacy HDDEs.…”

Persistent Organic Pollutant Reductions from a Diesel Engine Generator Fueled with Waste Cooking Oil-based Biodiesel Blended with Butanol and Acetone

“…: +886-8-7740263; Fax: +886-8-7740256 E-mail address: chensj@mail.npust.edu.tw (Attfield et al, 2012;IARC, 2012). In addition, several works have indicated that emissions of chlorine or bromine substituted pollutants, such as polychlorinated dibenzo-pdioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyl (PCBs), polybrominated dibenzo-p-dioxins and polybrominated dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs), are emitted not only from incinerators (Wei et al, 2016), electric arc furnaces and secondary aluminum smelters , but also from diesel engines (Laroo et al, 2011;Laroo et al, 2012;Cheruiyot et al, 2016).…”