The alteration and formation of toxic compounds and potential changes in the toxicity of emissions when using after-treatment technologies have gained wide attention. Volatile organic compound（VOC）, carbonyl compoun...The alteration and formation of toxic compounds and potential changes in the toxicity of emissions when using after-treatment technologies have gained wide attention. Volatile organic compound（VOC）, carbonyl compound and particle-phase polycyclic aromatic hydrocarbon（PAH） emissions were tested at European Steady State Cycle（ESC） to study unregulated emissions from a diesel engine with a fuel-borne catalyst and diesel particulate filter（FBC–DPF）. An Fe-based fuel-borne catalyst was used for this study. According to the results, brake specific emissions of total VOCs without and with DPF were 4.7 and4.9 mg/kWh, respectively, showing a 4.3% increase. Benzene and n-undecane emissions increased and toluene emission decreased, while other individual VOC emissions basically had no change. When retrofitted with the FBC–DPF, total carbonyl compound emission decreased 15.7%, from 25.8 to 21.8 mg/kWh. The two highest carbonyls, formaldehyde and acetaldehyde, were reduced from 20.0 and 3.7 to 16.5 and 3.3 mg/kWh respectively. The specific reactivity（SR） with DPF was reduced from 6.68 to 6.64 mg/kWh. Total particle-phase PAH emissions decreased 66.4% with DPF compared to that without DPF. However, the Benzo[a]pyrene equivalent（BaPeq） with DPF had increased from 0.016 to 0.030 mg/kWh.Fluoranthene and Pyrene had the greatest decrease, 91.1% and 88.4% respectively. The increase of two- and three-ring PAHs with DPF indicates that the fuel-borne catalyst caused some gas-phase PAHs to adsorb on particles. The results of this study expand the knowledge of the effects of using a particulate filter and a Fe-based fuel-borne catalyst on diesel engine unregulated emissions.展开更多
开展DOC和金属滤芯DPF对柴油机排气碳烟石墨化程度和氧化活性影响规律的研究,并分析了石墨化程度与氧化活性的相关性。结果表明:柴油机排气碳烟中2种方法所获得石墨化程度(AG/AD1和R值)及氧化反应表观活化能(Ea)分别处于0.205~0.293、0....开展DOC和金属滤芯DPF对柴油机排气碳烟石墨化程度和氧化活性影响规律的研究,并分析了石墨化程度与氧化活性的相关性。结果表明:柴油机排气碳烟中2种方法所获得石墨化程度(AG/AD1和R值)及氧化反应表观活化能(Ea)分别处于0.205~0.293、0.094~0.136及138.9~168.1 k J/mol之间;原机排放碳烟的AG/AD1、R值和Ea均随转速的升高而下降,随负荷的升高而提高;DOC处理后碳烟的AG/AD1、R值和Ea显著提高,且涨幅也基本上随转速的升高而下降,随负荷的升高而提高;多数工况下,金属滤芯DPF对AG/AD1、R值及Ea的影响极小;DOC处理前、后碳烟中AG/AD1或R值与Ea有一定相关性,且Ea对AG/AD1更敏感;DOC能够改善Ea与AG/AD1的相关性,但对Ea与R值的相关性影响不大。展开更多
基金financial support from the National Natural Science Foundation of China (No. 51276021)the Development Projects of Shandong Province Science and Technology (No. 2011YD17001)
文摘The alteration and formation of toxic compounds and potential changes in the toxicity of emissions when using after-treatment technologies have gained wide attention. Volatile organic compound（VOC）, carbonyl compound and particle-phase polycyclic aromatic hydrocarbon（PAH） emissions were tested at European Steady State Cycle（ESC） to study unregulated emissions from a diesel engine with a fuel-borne catalyst and diesel particulate filter（FBC–DPF）. An Fe-based fuel-borne catalyst was used for this study. According to the results, brake specific emissions of total VOCs without and with DPF were 4.7 and4.9 mg/kWh, respectively, showing a 4.3% increase. Benzene and n-undecane emissions increased and toluene emission decreased, while other individual VOC emissions basically had no change. When retrofitted with the FBC–DPF, total carbonyl compound emission decreased 15.7%, from 25.8 to 21.8 mg/kWh. The two highest carbonyls, formaldehyde and acetaldehyde, were reduced from 20.0 and 3.7 to 16.5 and 3.3 mg/kWh respectively. The specific reactivity（SR） with DPF was reduced from 6.68 to 6.64 mg/kWh. Total particle-phase PAH emissions decreased 66.4% with DPF compared to that without DPF. However, the Benzo[a]pyrene equivalent（BaPeq） with DPF had increased from 0.016 to 0.030 mg/kWh.Fluoranthene and Pyrene had the greatest decrease, 91.1% and 88.4% respectively. The increase of two- and three-ring PAHs with DPF indicates that the fuel-borne catalyst caused some gas-phase PAHs to adsorb on particles. The results of this study expand the knowledge of the effects of using a particulate filter and a Fe-based fuel-borne catalyst on diesel engine unregulated emissions.
文摘开展DOC和金属滤芯DPF对柴油机排气碳烟石墨化程度和氧化活性影响规律的研究,并分析了石墨化程度与氧化活性的相关性。结果表明:柴油机排气碳烟中2种方法所获得石墨化程度(AG/AD1和R值)及氧化反应表观活化能(Ea)分别处于0.205~0.293、0.094~0.136及138.9~168.1 k J/mol之间;原机排放碳烟的AG/AD1、R值和Ea均随转速的升高而下降,随负荷的升高而提高;DOC处理后碳烟的AG/AD1、R值和Ea显著提高,且涨幅也基本上随转速的升高而下降,随负荷的升高而提高;多数工况下,金属滤芯DPF对AG/AD1、R值及Ea的影响极小;DOC处理前、后碳烟中AG/AD1或R值与Ea有一定相关性,且Ea对AG/AD1更敏感;DOC能够改善Ea与AG/AD1的相关性,但对Ea与R值的相关性影响不大。
