Chapter 6 MARINE BIODIVERSITY IN KOREA: A REVIEW OF MACROZOOBENTHIC ASSEMBLAGES, THEIR DISTRIBUTIONS, AND LONG-TERM COMMUNITY CHANGES FROM HUMAN IMPACTS

oceanography, climate change, reefs, marine science, marine conservation, marine researc

Performance and emission characteristics of a vehicle fueled with enriched biogas and natural gases

This study aimed to investigate the characteristics of exhaust emissions and the fuel economy of a compressed natural gas (CNG) vehicle fueled with biogas and natural gases. A large CNG vehicle currently used as a city bus in Korea was tested on a chassis dynamometer under the European Transient Cycle (ETC) and the National Institute of Environmental Research (NIER) 06 cycles. One CH4-enriched biogas (97.6% CH4) and 5 natural gases with different CH4 contents (81.6-94.0% CH4) were used as test fuels. Total hydrocarbons (THC), CO, NOx and CO2 emissions in the NIER 06 cycle were higher than those in the ETC cycle for all tested fuels, while the fuel economy in the NIER 06 cycle was 43.7-51.5% lower than that in the ETC cycle. Total VOC emissions increased with increasing CH4 content in the fuel, with toluene being the highest proportion of the BTEX emissions in both the ETC cycle (72-80%) and the NIER 06 cycle (73-78%). Emissions of elemental/organic carbon exhibited a similar trend to that of nanoparticle emissions. Total organic carbon was mainly comprised of organic compounds at 97-99% (ETC cycle) and 95-99% (NIER 06 cycle). Polycyclic aromatic hydrocarbon emissions in the NIER 06 cycle were 133.3-577.8% higher than in the ETC cycle because of incomplete combustion and an increase in unburned fuel in the NIER 06 cycle, which is a low-speed driving mode. Nanoparticle number concentrations were lowest for M91 among the 6 tested fuels; the total number of particles in the NIER 06 cycle was 33.2-123.8% higher than in the ETC cycle.close7

Evaluation of regulated and unregulated emissions from a diesel powered vehicle fueled with diesel/biodiesel blends in Korea

The emission characteristics of diesel powered vehicles using conventional diesel fuel and six different biodiesel blends at proportions of 1% (B1), 3% (B3), 5% (B5), and 20% (B20) by volume were investigated. The emission tests were performed following the NEDC (New European Driving Cycle) and regulated and unregulated emissions were measured for two vehicles - one equipped with a DOC (diesel oxidation catalyst) and the other equipped with a DPF (diesel particulate filter). Emissions of THC (total hydrocarbon), CO, and PM (particulate matter) generally decreased with increasing biodiesel content in the fuel, while NOx emissions increased slightly in both vehicles. CO2 emissions were virtually identical. The extent of PM reduction in the DPF-equipped vehicle was almost 40 times higher than in the DOC-equipped vehicle. PAH (polycyclic aromatic hydrocarbon) emissions decreased with increasing biodiesel content in the fuel, with average reduction rates of the six biodiesels for particle-phase PAHs compared to the base diesel fuel in the range of 18.2-27.2% and 48.9-79.7% for the DOC- and DPF-equipped vehicles, respectively. Nanoparticle emissions from the DOC- and DPF-equipped vehicles were predominantly in the size range of 25.5-191.1 nm and <25.5 nm, respectively.close6