OTMT2015 CH2 - ANH HUONG CUA KHI THAI DCDT

Automotive and Air pollution Spring Semester 2015-2016 CHAPTER EFFECTS OF EXHAUST EMISSION Huynh Thanh Cong Ho Chi Minh City University of Technology Significance of the Exhaust Gas Emission Industry Traffic Definitions Domestic heating Emission: exhaust gas is emitted, for example, from exhaust or chimney; harmful components (gaseous, liquid, solid) are emitted into the environment Transmission/ Ambient concentration of pollutants Transmission: dilution of the exhaust gas after leaving the exhaust, further transport into the atmosphere, possibly chemical reactions at the same time - Topography - Meteorology - Physical - chemical reactions Countryside City Effects - Acute toxic effects, such as chronic and particularly carcinogenic effects on humans? - Effects on animals, plants, objects and global interactions? Source: Klingenberg Air quality: the concentration of the components in the air which finally sets after transmission when interacting in a specific place Effect: effect of components on the environment (e g on human beings) Exhaust Gas Components Carbon Dioxide – CO2  Properties • Colorless, odorless and tasteless gas • Heavier than air: CO2 = 1.97 kg/m³ > Air = 1.20 kg/m³ (20 °C; 101.3 kPa) • Nonflammable, extinguishes fire • Natural trace gas in the Earth's atmosphere (approx 0.040 %)  Effects on humans • CO2 is toxic in higher concentrations:  Concentrations of 7% to 10% cause dizziness, headache, visual and hearing dysfunction  More than % CO2 in breathable air result in death within 30 to 60 minutes (Asphyxiation)  Environmental effects • Carbon dioxide is a greenhouse gas, so CO2 from fossil fuel burning contributes to global warming (anthropogenic greenhouse effect) • With photosynthesis the plants generate carbohydrates from CO2, so that is the raw material of any biomass Ozone (O3) from Exhaust of Internal Combustion Engines  Properties • Ozone is a pale blue gas having a very specific sharp odor • Heavier than air (O3 = 2.14 kg/m³ at °C and 101.3 kPa) • Powerful oxidizing agent, in contact with many materials => explosion hazard  Effects on humans • Toxic and caustic • Exposure of 0.1 to ppm O3 produces harmful effects on the respiratory systems, cough, headache, burning eyes, and irritation to the respiratory passage • Long-term objective for protection of human health in the European Union: 120 àg/m (DIRECTIVE 2008/50/EC) ã National Ambient Air Quality Standard: 8-hour “primary” ozone standard = 0.075 ppm (US EPA, 2008)  Environmental effects • In the stratosphere the ozone layer acts as a filter against strong UV-radiation (UV-C and UV-B) and hence it is essential for life • Ozone-smog: ground-level ozone is formed by chemical reactions between NOx and volatile organic compounds (VOC) in the presence of heat and sunlight • Ozone damages the vegetation Exhaust Gas Components Limited Pollutants: Carbon monoxide - CO  Properties • Colorless, odorless and tasteless gas • Slightly lighter than air: CO = 1.16 kg/m³ < Air = 1.20 kg/m³ (20 °C, 101.3 kPa) • Highly flammable → explosion hazard  Effects on humans • Highly toxic to humans: CO blocks the transportation of oxygen in blood • Exposures at 100 ppm or greater is dangerous to human health, 0.3 % result in death within 30 minutes • Carbon monoxide is carcinogenic, mutagenic and toxic for reproduction and may have severe adverse effects on the fetus of a pregnant woman  Environmental effects • • Mammals: effects are similar like on human beings Plants: damage of chlorophyll (CO is a photosynthesis poison) Exhaust Gas Components Limited Pollutants: Hydrocarbons - HC  Name Term for the variety of hydrocarbons (THC) NMHC: HC without methane (CH4)  Properties THC - Total Hydro Carbons NMHC - Non-Methane HC NMVOC - Non-Methane Volatile Organic Compounds NMOG - Non-Methane Organic Gases PAH - Polycyclic Aromatic HC white smoke at start of engine mostly highly volatile  Effects on human Irritation of the mucosa Odor nuisance PAH, formaldehyde a o are carcinogenic  Environmental effects Support of ozone formation (with NOX formation of photo oxidants → summer smog) Exhaust Gas Components Limited Pollutants: Nitrogen Oxides - NOX  Name Term for the sum of NO (90 - 95 %) and NO2 (5-10 %)  Properties NO: color-, odor- and tasteless gas, transforms into NO2 in air NO2: poisonous, auburn, pungent smelling gas, dissolves in water → nitric acid  Effects on human Irritation of the mucosa Caustic Oxygen transportation in blood is impaired  Environmental effects Support of ozone formation (with HC formation of photo oxidants → summer smog) Limited Pollutant Components Particles – Definitions  Aerosol physics: In air dispersed particles are considered as air pollutants, if they are so small that they remain in abeyance and being able to harm the organism, upper diameter limit: 57 µm (according to the velocity at which a spherical particle of diameter 100 nm and density = g/cm³ sinks)  Environmental legislation: Nanoparticles : Particles smaller then 50 nm Ultra fine particles : Particles smaller then 100 nm Fine particles : Particles smaller then 2.5 µm (formerly also < 10 µm) Coarse Particle : Particles bigger then 2.5 µm (formerly also > 10 µm) (in English speaking areas ”coarse” fraction particles are understood to be bigger then 2.5 µm but smaller then 10 µm) PM10 : Particles which pass through an air intake which selects particles sizes This air intake has, for an aerodynamic diameter of 10 µm, a separation effectiveness of 50% (official definition from EU guidelines) Source: UBA, Hintergrundpapier z Thema Staub/Feinstaub (PM) Berlin, März 2005  Industrial medicine: Total mass of the elementary carbon (soot) in the air in the diameter size range < µm  EPA: Particulate Matter (PM) are the exhaust components, which can be separated from diluted exhaust gas at temperature of max +52°C (125 °F) on teflon-coated filters The mass is determined by weighing the filters (gravimetric method) Source: Mayer, Minimization of the particle issues expert, 2004 Systematic of the Particulates in Diesel Source: Klingenberg Particle Size Range for Different Particles [µm] 10-4 0,001 10 0,01 0,1 10 100 104 Dust Smoke Technical Definitions 1000 Mist Spray Wear and Exhaust Gas of Internal Combustion Engines Fertilizer, Limestone Abraded Rubber Typical Particles Oil Smoke Fly Ash Tobacco Smoke Coal Dust Cement Dust Carbon Black Metallurgical Dust Insecticide Dust • H2 Combustion Nuclei • O2 Milled Flour Sea Salt Nuclei • SO2 0,1 Plant Spores Alkali Fume • CO2 [nm] Pollens Bacteria Viruses 10 10 100 1000 104 105 106 107 Source: D B Kittelson Soot Particles Nucleation, Accumulation, and Coarse Particles Fraction Source: D B Kittelson ... same time - Topography - Meteorology - Physical - chemical reactions Countryside City Effects - Acute toxic effects, such as chronic and particularly carcinogenic effects on humans? - Effects... Pollutants: Hydrocarbons - HC  Name Term for the variety of hydrocarbons (THC) NMHC: HC without methane (CH4)  Properties THC - Total Hydro Carbons NMHC - Non-Methane HC NMVOC - Non-Methane Volatile... stratosphere the ozone layer acts as a filter against strong UV-radiation (UV-C and UV-B) and hence it is essential for life • Ozone-smog: ground-level ozone is formed by chemical reactions between NOx