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Abstract: Formaldehyde and acetaldehyde are toxic carcinogens so their reductions in diesel-engine emissions are desirable. This study investigated emissions of carbonyl compounds (CBCs) from an HDDE (heavy-duty diesel engine) at US transient cycle test, using five test fuels: premium diesel fuel (D100), P100 (100% palm-biodiesel), P20 (20% palm-biodiesel + 80% premium diesel fuel), PF80P20 (80% paraffinic fuel + 20% palm-biodiesel), and PF95P05 (95% paraffinic fuel + 5% palm-biodiesel). Experimental results indicate that formaldehyde was the major carbonyl in the exhaust, accounting for 70.1–76.2% of total CBC concentrations for all test fuels. In comparison with D100 (172 mg BHP−1 h−1), the reductions of formaldehyde and acetaldehyde emission factor for P100, P20, PF80P20, and PF95P05 were (−16.8%, −61.8%), (−10.0%, −39.0%), (21.3%, 1.10%), and (31.1%, 19.5%), respectively. Using P100 and P20 instead of D100 in the HDDE increased CBC concentrations by 14.5% and 3.28%, respectively, but using PF80P20 and PF95P05 significantly reduced CBC concentrations by 30.3% and 23.7%, respectively. Using P100 and P20 instead of D100 (2867 ton yr−1) in the HDDE increased CBC emissions by 240 and 224 ton yr−1, respectively, but using PF80P20, and PF95P05 instead of D100 in the HDDE decreased CBC emissions by 711 and 899 ton yr−1, respectively. The above results indicate that the wide usage of paraffinic–palmbiodiesel blends as alternative fuels could protect the environment. [Copyright &y& Elsevier]

This study investigated the emissions of carbonyl compounds (CBCs) and regulated harmful matters (traditional pollutants) from an HDDE (heavy-duty diesel engine) at one low load steady-state condition, 24.5% of the max load (40 km h−1), using five test fuels: premium diesel fuel (D100), P100 (100% palm-biodiesel), P20 (20% palm-biodiesel + 80% premium diesel fuel), PF80P20 (80% paraffinic fuel + 20% palm-biodiesel), and PF95P05 (95% paraffinic fuel + 5% palm-biodiesel). Experimental results indicate that formaldehyde was the major carbonyl in the exhaust, accounting for 70.3–75.4% of total CBC concentrations for all test fuels. Using P100 and P20 instead of D100 in the HDDE increased CBC concentrations by 9.74% and 2.89%, respectively. However, using PF80P20 and PF95P05 as alternative fuels significantly reduced CBC concentrations by 30.3% and 24.2%, respectively. Using PF95P05 instead of D100 decreased CBCs by 30.3%, PM by 11.1%, THC by 39.0%, CO by 34.0%, NOx by 24.3%, and CO2 by 7.60%. The wide usage of paraffinic–palmbiodiesel blends as alternative fuels could protect the environment. However, it should be noted that only one engine operated at one low load steady-state condition was investigated. [Copyright &y& Elsevier]

Biodiesels are promoted as alternatives to fossil fuels and their applications in diesel engine have been studied extensively. However, the size distribution of polycyclic aromatic hydrocarbons (PAHs) and generator particulate material (GPM) emitted from heavy-duty diesel generator fueled with biodiesel blends has seldom been addressed. Seven different biodiesel blends with volume fractions of biodiesel ranging from 0% to 30% were studied. Experimental results indicate that the mean reductions of sum of PAHi/GPM0.056–18 (generator particulate material with aerodynamic diameter 0.056–18μm) and BaPeqi [=(benzo[a]pyrene equivalent)i]/GPM0.056–18 of B5, B10, B15, B20, B25 and B30 are (−8.21%, −5.72%), (−36.7%, −29.7%), (−1.25%, 2.32%), (16.2%, 18.6%), (33.4%, 35.0%) and (40.5%, 42.4), respectively, compared with B0. Both PAHi/GPMi and BaPeqi/GPMi in stage 1 (0.056–0.166μm) and stage 2 (0.166–0.31μm) of all test fuels are higher than those in the other stages due to higher specific surface area of smaller particles. It is also observed that there are more highly toxic PAHs in stage 2. It should be noticed that the trend of particle-phase PAH contents is different from the trend of particle-phase PAH concentration and opposite to the trend of total GPM0.056–18 emission. The differences are due to a higher number of particles with diameters between 0.056 and 0.31μm. The above results indicate that fuel blends with less than 15% biodiesel would increase PAH content at particle size between 0.056 and 0.31μm. Therefore, the blending fraction should be between 15% and 30%. Moreover, particle-size control is needed in future emission regulations which would necessitate further improvements in combustion quality. Besides, researches on health effects of biodiesel blends are needed as well. [Copyright &y& Elsevier]

Abstract: Biodiesels are promoted as alternative fuels and their applications in diesel engines have been investigated by many researchers. However, the particle size distribution emitted from heavy-duty diesel engines fueled with palm-biodiesel blended with premium diesel fuel and paraffinic fuel blended with palm-biodiesel has seldom been addressed. Thus, five test fuels were used in this work to study the particle size distribution: D100 (premium diesel fuel), B100 (100% palm-biodiesel), B20 (20vol% palm-biodiesel+80vol% D100), BP9505 (95vol% paraffinic fuel+5vol% palm-biodiesel) and BP8020 (80vol% paraffinic fuel+20vol% palm-biodiesel). A Micro-Orifice Uniform Deposit Impactor (MOUDI) equipped with aluminum filters was used to collect size-resolved samples. Experimental results indicated that palm-biodiesel blends and paraffinic fuel blends could improve combustion efficiency in diesel engines, but pure palm-biodiesel could cause incomplete combustion. Adding palm-biodiesel to diesel fuel would slightly increase particles with diameter <0.31μm but paraffinic fuel blends could decrease particles with diameter <1μm. The mass median diameter of overall particles (MMDo) and σ g,o are 0.439μm and 3.88 for D100; 0.380μm and 3.24 for B20; 0.465μm and 4.22 for B100; 1.40μm and 4.92 for BP9505; 1.46μm and 2.25 for BP8020. There are more particles with low aerodynamic diameters (diameter <0.31μm) in the exhaust of D100, B20 and B100 fuels. On the other hand, a greater fraction of particulate matter of BP9505 and BP8020 existed in coarse particles (diameter: 2.5–10μm). Energy efficiency also increases significantly by 12.3–15.1% with the introduction of paraffinic fuel blends into the engine. Nevertheless, paraffinic fuel blends also reduce the emission of particulate matters by 36.0–38.4%. Carbon monoxide was decreased by 36.8–48.5%. Total hydrocarbon is 39.6–41.7% less than diesel fuel combustion. Nitrogen oxides emission is about 5% lower for paraffinic fuel. These results show that paraffinic fuel can be very competitive and replaced diesel fuels in the future. [Copyright &y& Elsevier]

Abstract: This study investigated the emissions of polycyclic aromatic hydrocarbons (PAHs), carcinogenic potencies (BaPeq) and particulate matter (PM), fuel consumption and energy efficiency from the generator under steady state for seven test fuels: P0 (Premium Diesel Fuel), P10 (10% palm biodiesel+90% P0), P20, P30, P50, P75 and P100. Experimental results indicated that PAH emission decreased with increasing palm-biodiesel blends due to small PAH content in biodiesel. The mean reduction fraction of total PAHs emission factor (P0=1110μgL−1) from the exhaust of diesel generator were 13.2%, 28.0%, 40.6%, 54.4%, 61.89% and 98.8% for P10, P20, P30, P50, P75 and P100, respectively, compared with P0. The mean reduction fraction of total BaPeq (P0=1.65μgL−1) from the exhaust of diesel generator were 15.2%, 29.1%, 43.3%, 56.4%, 58.2% and 97.6% for P10, P20, P30, P50, P75 and P100, respectively, compared with P0. PM emission decreased as the palm-biodiesel blends increased from 0% to 10%, and increased as the palm-biodiesel blends increased from 10% to 100% because the soluble organic fraction of PM emission was high in blends with high palm-biodiesel content. The brake specific fuel consumption rose with rising palm-biodiesel blends due to the low gross heat value of palm-biodiesel. The increasing fraction of BSFC of palm-biodiesel was lower than those of soy-, soapstock-, brassica-carinate and rapeseed-biodiesel. Palm-biodiesel seems to be the most feasible biodiesel. The best energy efficiency occurred between P10 and P20, close to P15. The curve dropped as the palm-biodiesel content rose above P20. Above results revealed that palm-biodiesel was an oxygenated fuel appropriate for use in diesel engines to promote combustion efficiency and decrease PAH emission. However, adding an excess of palm-biodiesel to P0 leaded to incomplete combustion in the diesel-engine generator and inhibited the release of energy in the fuel. [Copyright &y& Elsevier]

Abstract: Because of the fishery subsidy policy, the fishing boat fuel oil (FBFO) exemption from commodity taxes, business taxes and air pollution control fees, resulted in the price of FBFO was ∼50% lower than premium diesel fuel (PDF) in Taiwan. It is estimated that ∼650,000kL FBFO was illegally used by traveling diesel-vehicles (TDVs) with a heavy-duty diesel engine (HDDE), which accounted for ∼16.3% of the total diesel fuel consumed by TDVs. In this study, sulfur, poly aromatic and total-aromatic contents in both FBFO and PDF were measured and compared. Exhaust emissions of polycyclic aromatic hydrocarbons (PAHs) and their carcinogenic potencies (BaPeq) from a HDDE under transient cycle testing for both FBFO and PDF were compared and discussed. Finally, the impact caused by the illegal use of FBFO on the air quality was examined. Results show that the mean sulfur-, poly aromatic and aromatic-contents in FBFO were 43.0, 3.89 and 1.04 times higher than that of PDF, respectively. Emission factors of total-PAHs and total-BaPeq obtained by utilizing FBFO were 51.5 and 0.235mgL−1-Fuel, which were 3.41 and 5.82 times in magnitude higher than obtained by PDF, respectively. The estimated annual emissions of total-PAHs and total-BaPeq to the ambient environment due to the illegally used FBFO were 23.6 and 0.126 metric tons, respectively, which resulted in a 17.9% and a 25.0% increment of annual emissions from all mobile sources, respectively. These results indicated that the FBFO used illegally by TDVs had a significant impact on PAH emissions to the ambient environment. [Copyright &y& Elsevier]

Abstract: In recent years, the celebration activities of various folk-custom festivals have been getting more and more attention from the citizens in Taiwan. Festivities throughout the whole island are traditionally accompanied by loud and brightly colored firework displays. Among these activities, the firework displays during Taiwan''s Lantern Festival in Kaohsiung harbor is one of the largest festivals in Taiwan each year. Therefore, it is of importance to investigate the influence of fireworks displays on the ambient air quality during the Taiwan''s Lantern Festival. Field measurements of atmospheric particulate matter (PM) were conducted on February 9th–11th, 2009 during Taiwan''s Lantern Festival in Kaohsiung City. Moreover, three kinds of fireworks powders obtained from the same manufacturing factory producing Kaohsiung Lantern Festival fireworks were burned in a self-designed combustion chamber to determine the physicochemical properties of the fireworks'' particles and to establish the source profile of firework burning. Several metallic elements of PM during the firework display periods were notably higher than those during the non-firework periods. The concentrations of Mg, K, Pb, and Sr in PM2.5 during the firework periods were 10 times higher than those during the non-firework periods. Additionally, the Cl−/Na+ ratio was approximately 3 during the firework display periods as Cl− came from the chlorine content of the firework powder. Moreover, the OC/EC ratio increased up to 2.8. Results obtained from PCA and CMB receptor modeling showed that major sources of atmospheric particles during the firework display periods in Kaohsiung harbor were fireworks, vehicular exhausts, soil dusts and marine sprays. Particularly, on February 10th, the firework displays contributed approximately 25.2% and 16.6% of PM10 at two downwind sampling sites, respectively. [Copyright &y& Elsevier]

This study investigates ammonium, nitrate, and sulfate (NH4 +, NO3 −, and SO4 2−) in size-resolved particles (particularly nano (PM0.01–0.056)/ultrafine (PM0.01–0.1)) and NOx/SO2 collected near a busy road and at a rural site. The average (mass) cumulative fraction of secondary inorganic aerosols (SO4 2−+NO3 −+NH4 +) in nano or ultrafine particles at the roadside was found to be three to four times that at the rural site. The above three secondary inorganic aerosol species were present in similar cumulative fractions in particles of size 1–18 μm at both sites; however, dissimilar fractions were observed for Cl−, Na+, and K+. The nitrogen ratios (NRs: NR = NO3 −−N/(NO3 −−N + NO2–N)), sulfur ratios (SRs: SR = SO4 2−−S/(SO4 2−−S + SO2–S)), dNR/DP (derivative of NR with respect to DP (particle diameter)), and dSR/DP (derivative of SR with respect to DP) at the roadside were higher than those at the rural site for nano/ultrafine particles. At both sites (particularly the roadside), the nanoparticles had significantly higher dNR/DP and dSR/DP values than differently sized particles, implying that NO3 −/SO4 2− (from NO2/SO2 transformation or NO3 −/SO4 2− deposition) were present on these particles. [Copyright &y& Elsevier]