The Experts below are selected from a list of 69 Experts worldwide ranked by ideXlab platform
Nils Friedrich - One of the best experts on this subject based on the ideXlab platform.
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influence of vessel characteristics and atmospheric processes on the gas and particle phase of ship emission plumes in situ measurements in the mediterranean sea and around the arabian peninsula
Atmospheric Chemistry and Physics, 2020Co-Authors: Siddika Celik, Frank Drewnick, Friederike Fachinger, James Brooks, Eoghan Darbyshire, Jeandaniel Paris, Philipp G Eger, Jan Schuladen, Ivan Tadic, Nils FriedrichAbstract:Abstract. A total of 252 emission plumes of ships operating in the Mediterranean Sea and around the Arabian Peninsula were investigated using a comprehensive dataset of gas- and submicron-particle-phase properties measured during the 2-month shipborne AQABA (Air Quality and Climate Change in the Arabian Basin) field campaign in summer 2017. The post-measurement identification of the corresponding ship emission events in the measured data included the determination of the plume sources (up to 38 km away) as well as the plume ages (up to 115 min) and was based on commercially available historical records of the Automatic Identification System. The dispersion lifetime of chemically inert CO2 in the ship emission plumes was determined as 70±15 min, resulting in levels indistinguishable from the marine background after 260±60 min. Emission factors (EFs) as quantities that are independent of plume dilution were calculated and used for the investigation of influences on ship emission plumes caused by ship characteristics and the Combustion process as well as by atmospheric processes during the early stage of exhaust release and during plume ageing. Combustion Efficiency and therefore emission factors of black carbon and NOx were identified to depend mostly on the vessel speed and gross tonnage. Moreover, larger ships, associated with higher engine power, were found to use fuel with higher sulfur content and have higher gas-phase SO2 , particulate sulfate, particulate organics, and particulate matter EFs. Despite the independence of EFs of dilution, a significant influence of the ambient wind speed on the particle number and mass EFs was observed that can be traced back to enhanced particle coagulation in the case of slower dilution and suppressed vapour condensation on particles in the case of faster dilution of the emission plume. Atmospheric reactions and processes in ship emission plumes were investigated that include NOx and O3 chemistry, gas-to-particle conversion of NOx and SO2 , and the neutralisation of acids in the particle phase through the uptake of ambient gas-phase ammonia, the latter two of which cause the inorganic particulate content to increase and the organic fraction to decrease with increasing plume age. The results allow for us to describe the influences on (or processes in) ship emission plumes quantitatively by parameterisations, which could be used for further refinement of atmospheric models, and to identify which of these processes are the most important ones.
Liu Hao - One of the best experts on this subject based on the ideXlab platform.
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Oxy-coal Combustion in a 30kWth pressurized fluidized bed: Effect of Combustion pressure on Combustion performance, pollutant emissions and desulfurization
'Elsevier BV', 2020Co-Authors: Pang Lei, Shao Yingjua, Zhong Wenqi, Liu HaoAbstract:Oxy-coal Combustion with pressurized fluidized beds has recently emerged as a promising carbon capture and storage (CCS) technology for coal-fired power plants. Although a large number of energy Efficiency analyses have shown that an increase in Combustion pressure can further increase the net plant Efficiency, there are few experimental studies of pressurized oxy-coal Combustion conducted on fluidized bed combustors/boilers with continuous coal feeding. In this study, oxy-coal Combustion experiments with lignite and anthracite were conducted with a 30 kWth pressurized fluidized bed combustor within the pressure range of 0.1 MPa to 0.4 MPa. The investigation focused on the elucidation of the impacts of Combustion pressure on the Combustion performance, pollutant emissions and desulfurization of oxy-coal Combustion in fluidized beds. The results showed that an increase in pressure increased the Combustion Efficiency and Combustion rate of coal particles, and the promoting effect of pressure increase was more significant for the high rank coal with smaller particle size and the high O2 concentration atmosphere. For both coals, NOx emissions decreased with pressure but N2O emissions increased with pressure and accounted for a considerable part of the nitrogen oxide pollutants under high pressure oxy-coal Combustion conditions. The pressure had insignificant impact on the SO2 emissions of oxy-coal Combustion but an increase in pressure enhanced the direct desulfurization of limestone
Hinwood, Andrea L. - One of the best experts on this subject based on the ideXlab platform.
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Emissions of gaseous pollutants from laboratory-based fires of vegetation from five common vegetation types in Western Australia
'Elsevier BV', 2020Co-Authors: Dong, Trang T.t., Hinwood, Andrea L., Callan, Anna C., Stock, William D.Abstract:This study investigated emission factors (EFs) for CO2, CO, NO and carbonyls from laboratory-based Combustion of five typical vegetation types of Western Australia. A range of Combustion conditions was obtained by controlling the vegetation moisture content and air flow rate. CO2, CO and NO were measured using a multi-gas monitor MultiRAE. Six carbonyls were collected using 2,4-DNPH sorbent tubes and analysed using HPLC-UV. Burns of woodland (Banksia) and forest (Jarrah) had significantly higher EFCO, with lower modified Combustion Efficiency (MCE) than those of tropical grass (Spinifex). Temperate grass (Veldt) fires had lower EFCO2 and higher EFCO and EFcarbonyls, and a much lower MCE than those of the tropical grass fires. EFNO were similar for woodland, forest and tropical grass but large differences in EFNO were observed for Spinifex and Veldt grass. Formaldehyde was the most abundant carbonyl emitted. Combustion conditions influenced the EFcarbonyls with larger EFs from burns with higher fuel moisture contents and/or at higher flow rates. Functions to extrapolate EFs for infrequently measured carbonyls (acetaldehyde, acetone and propionaldehyde) from EFformaldehyde were developed. The EFCO2 and EFCO were similar to values reported from field measurements for similar ecosystems in Australia, indicating the applicability of these laboratory-based results. EFs for other gases differed to those reported from bushfires in other parts of the world suggesting that to improve prediction of bushfire emissions and impacts in Australia, EFs of all fire-prone Australian vegetation types should be determined, particularly for those in close proximity to densely populated areas. © 2020 Turkish National Committee for Air Pollution Research and Contro
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Emission factors and composition of PM2.5 from laboratory Combustion of five Western Australian vegetation types
'Elsevier BV', 2020Co-Authors: Dong, Trang T. T., Callan, Anna C., Stock William, Strandberg O, Hinwood, Andrea L.Abstract:This study investigated the emission of PM10 and PM2.5 (particulates with diameters of less than 10 µm and 2.5 µm, respectively) and the chemical composition of PM2.5 from laboratory Combustion of five Australian vegetation types (three grasslands, a woodland and a forest). A mix of plants representative of Banksia (woodland) and Jarrah (forest) and three types of grasses (Spinifex – Triodia basedowii; Kimberley grass – Sehima nervosum and Heteropogon contortus; and an invasive grass (Veldt) – Ehrharta calycina) were burnt in 9 Combustion conditions comprised of 3 fuel moisture levels (dry, moist, wet) and 3 air flow rates (no, low and high flow). PM (particulate matter) samples were collected onto filters and measured using gravimetric analysis. PM2.5 was then extracted and analyzed for water-soluble metals and polycyclic aromatic hydrocarbons (PAH) concentrations. The largest proportion of PM10 (98%) from vegetation fires was PM2.5. Banksia yielded the highest PM2.5 emission factor (EF), followed by Jarrah and Spinifex. Veldt grass Combustion generated significantly higher emissions of PM2.5 compared with the other two grass types. High moisture contents and flow rates resulted in larger emissions of PM2.5. A strong correlation (R2 = 0.84) was observed between the EF for PM2.5 and Combustion Efficiency, suggesting higher PM emission with lower Combustion efficiencies. Potassium and sodium were the most abundant PM2.5-bound water soluble metals, accounting for more than 97% of the total mass of metals analyzed. PAHs were found in significant concentrations, including the carcinogenic benzo(a)pyrene. Pyrene and fluoranthene were the most abundant PAHs detected, accounting for nearly 40% mass of the total PAHs. Indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene ratio (IND/IND + BghiP) appeared to be produced in a diagnostic ratio that indicated that the PAHs were derived from vegetation fires rather than other sources of emissions. The EF for PM2.5 and its chemical composition (water-soluble metals and PAHs) were strongly influenced by the type of vegetation burned. The results presented in this study could be useful in predicting the risks of human health effects on firefighters and the public who may be exposed to regular bushfires in Australia
Siddika Celik - One of the best experts on this subject based on the ideXlab platform.
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influence of vessel characteristics and atmospheric processes on the gas and particle phase of ship emission plumes in situ measurements in the mediterranean sea and around the arabian peninsula
Atmospheric Chemistry and Physics, 2020Co-Authors: Siddika Celik, Frank Drewnick, Friederike Fachinger, James Brooks, Eoghan Darbyshire, Jeandaniel Paris, Philipp G Eger, Jan Schuladen, Ivan Tadic, Nils FriedrichAbstract:Abstract. A total of 252 emission plumes of ships operating in the Mediterranean Sea and around the Arabian Peninsula were investigated using a comprehensive dataset of gas- and submicron-particle-phase properties measured during the 2-month shipborne AQABA (Air Quality and Climate Change in the Arabian Basin) field campaign in summer 2017. The post-measurement identification of the corresponding ship emission events in the measured data included the determination of the plume sources (up to 38 km away) as well as the plume ages (up to 115 min) and was based on commercially available historical records of the Automatic Identification System. The dispersion lifetime of chemically inert CO2 in the ship emission plumes was determined as 70±15 min, resulting in levels indistinguishable from the marine background after 260±60 min. Emission factors (EFs) as quantities that are independent of plume dilution were calculated and used for the investigation of influences on ship emission plumes caused by ship characteristics and the Combustion process as well as by atmospheric processes during the early stage of exhaust release and during plume ageing. Combustion Efficiency and therefore emission factors of black carbon and NOx were identified to depend mostly on the vessel speed and gross tonnage. Moreover, larger ships, associated with higher engine power, were found to use fuel with higher sulfur content and have higher gas-phase SO2 , particulate sulfate, particulate organics, and particulate matter EFs. Despite the independence of EFs of dilution, a significant influence of the ambient wind speed on the particle number and mass EFs was observed that can be traced back to enhanced particle coagulation in the case of slower dilution and suppressed vapour condensation on particles in the case of faster dilution of the emission plume. Atmospheric reactions and processes in ship emission plumes were investigated that include NOx and O3 chemistry, gas-to-particle conversion of NOx and SO2 , and the neutralisation of acids in the particle phase through the uptake of ambient gas-phase ammonia, the latter two of which cause the inorganic particulate content to increase and the organic fraction to decrease with increasing plume age. The results allow for us to describe the influences on (or processes in) ship emission plumes quantitatively by parameterisations, which could be used for further refinement of atmospheric models, and to identify which of these processes are the most important ones.
Stock, William D. - One of the best experts on this subject based on the ideXlab platform.
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Emissions of gaseous pollutants from laboratory-based fires of vegetation from five common vegetation types in Western Australia
'Elsevier BV', 2020Co-Authors: Dong, Trang T.t., Hinwood, Andrea L., Callan, Anna C., Stock, William D.Abstract:This study investigated emission factors (EFs) for CO2, CO, NO and carbonyls from laboratory-based Combustion of five typical vegetation types of Western Australia. A range of Combustion conditions was obtained by controlling the vegetation moisture content and air flow rate. CO2, CO and NO were measured using a multi-gas monitor MultiRAE. Six carbonyls were collected using 2,4-DNPH sorbent tubes and analysed using HPLC-UV. Burns of woodland (Banksia) and forest (Jarrah) had significantly higher EFCO, with lower modified Combustion Efficiency (MCE) than those of tropical grass (Spinifex). Temperate grass (Veldt) fires had lower EFCO2 and higher EFCO and EFcarbonyls, and a much lower MCE than those of the tropical grass fires. EFNO were similar for woodland, forest and tropical grass but large differences in EFNO were observed for Spinifex and Veldt grass. Formaldehyde was the most abundant carbonyl emitted. Combustion conditions influenced the EFcarbonyls with larger EFs from burns with higher fuel moisture contents and/or at higher flow rates. Functions to extrapolate EFs for infrequently measured carbonyls (acetaldehyde, acetone and propionaldehyde) from EFformaldehyde were developed. The EFCO2 and EFCO were similar to values reported from field measurements for similar ecosystems in Australia, indicating the applicability of these laboratory-based results. EFs for other gases differed to those reported from bushfires in other parts of the world suggesting that to improve prediction of bushfire emissions and impacts in Australia, EFs of all fire-prone Australian vegetation types should be determined, particularly for those in close proximity to densely populated areas. © 2020 Turkish National Committee for Air Pollution Research and Contro