Particulate emissions from diesel engines have been a key issue for diesel engine developers in recent decades. Their work has succeeded in reducing the exhaust particles from the combustion of fuel, which has led to increasing interest in the contribution of particulates from lubrication oil. When discussing oil-related particulate emissions, hydrocarbon particles are customarily referred to. This thesis uses a broader definition, in which oil-related particulate emissions are modelled not only by the hydrocarbons, but also include the ash, carbons, and sulphate oil particulate emissions. The model developed in the project uses input data as oil consumption and oil ash content combined with tuning parameters, such as the oil ash transfer rate (ash emissions divided by oil consumption and oil ash content). Controlled engine tests have been performed to verify assumptions and fill knowledge gaps. The model can be applied to a variety of diesel engines, although the tuning factors might have to be reset. For example, introducing diesel particulate filters would dramatically reduce the oil ash emissions, since oil ash would accumulate in the filter. Oil consumption has played a central role in the present research. The modelling results indicate that special attention should be paid to oil consumption under running conditions with a low in-cylinder temperature, since the oil survival rate is high there. Under low-load and motoring conditions, hydrocarbons proved to be the main contributor to oil-related particulate emissions. At high engine load, oil ash emissions were the largest contributor to oil-related particulate emissions. / QC 20101103

Burning joss paper and incense is a significant Taoist ceremonial practice in Asian countries such as Taiwan and China. The burning of joss paper has been demonstrated to significantly create particulate matters (PM) and to cause air pollution problems. PM in the atmosphere is among the primary air pollutants, and their sources are factories, vehicles, construction fields, combustion, vehicle exhaust dust, and aerosols derived from photochemical reactions. Numerous sources of environmental PM exist. Thus, the ability to rapidly determine the particulate type and source to adjust the controls and develop policies is an important issue for air quality management. This dissertation consists of two parts on the particulate emission control and characteristic identification. In the first part, we study investigates feasible options of air pollution control devices (APCD) for joss paper furnaces in temples, and used a 40 kg/hr joss paper furnace for testing. This paper examined particulate removal efficiencies of two options: a bag house (capacity 30 m3/min at 108 ¢J) and a wet scrubber (capacity 40 m3/min at 150 ¢J). The results indicate that PM in the diluted flue gas at the bag-house inlet were 76.6 ¡Ó 32.7 mg/Nm3 (average ¡Ó standard deviation), and those at the outlet of the bag-house could be reduced to as low as 0.55 ¡Ó 1.28 mg/Nm3. An average PM removal efficiency of 99.3 % could be obtained with a filtration speed of approximately 2.0 m/min evaluated at 108 ¢J. The wet scrubber removed approximately 70 % of PM, with scrubbing intensities higher than 4.0 L/m2.s across the scrubber cross-section. For the duration of the experiment, no visual white smoke (water mist) was observed at the exit of the wet scrubber with a combustion rate of 16 kg/hr of joss paper, and the scrubbing water temperature was automatically sustained at lower than 61 ¢J. The study concluded that both bag filtration and wet scrubbing are suitable techniques to control particulate emission from joss paper furnaces in Taiwanese temples. The bag filtration technique, while achieving higher efficiencies than the wet scrubbing technique, requires more space and cost. Examinations of bottom and fly ashes of combusted joss paper with X-ray diffraction (XRD) revealed the presence of calcium oxide in the fly ash, while certain metals were found in the bottom ash. The second part aimed at the investigates surface characteristics of airborne PM sampled from air pollution control devices of a number of industrial operations. The PM sources selected for this study comprise the following operations or processes: a coke oven, iron ore sintering furnace, blast furnace, and basic oxygen furnace from an integrated steelmaking plant; electric arc furnaces of two secondary steelmaking plants; a municipal solids waste incinerator; two oil-fired boilers; and a coal-fired power plant boiler. The collected PM samples were analyzed using a scanning electronic microscope (SEM) and energy-dispersive X-ray spectroscope (EDS) to determine their chemical composition and surface characteristics. Results for each PM sample regarding size, surface characteristics, and chemical compositions can be used to trace the related emission industrial sources.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Ronaldo G. Maghirang / Emissions of particulate matter (PM) are an increasing concern for large open beef cattle feedlots. Research is needed to develop science-based information on PM emissions and abatement measures for mitigating those emissions. This research was conducted to (1) measure PM concentrations emitted from large cattle feedlots, (2) compare different samplers for measuring concentrations of PM with equivalent aerodynamic diameter of 10 µm or less (PM10), (3) evaluate the relative effectiveness of pen surface treatments in reducing PM10 emissions, and (4) predict PM control efficiency of vegetative barriers. Concentrations of PM with equivalent aerodynamic diameter of 2.5 µm or less (PM2.5), PM10, and total suspended particulates (TSP) upwind and downwind of two large cattle feedlots (KS1, KS2) in Kansas were measured with gravimetric samplers. The downwind and net concentrations generally decreased with increasing water content (WC) of the pen surface; for effective control of PM emissions from feedlots, it appears that pen surface WC should be at least 20% (wet basis). Three types of samplers for measuring PM10 concentrations in feedlots KS1 and KS2 were compared: Tapered Element Oscillating Microbalance™ (TEOM), high-volume (HV), and low-volume (LV) PM10 samplers. Measured PM10 concentration was generally largest with the TEOM PM10 sampler and smallest with the LV PM10 sampler. A laboratory apparatus was developed for measuring the PM10 emission potential of pen surfaces as affected by surface treatments. The apparatus was equipped with a simulated pen surface, mock cattle hooves that moved horizontally across the pen surface, and PM10 samplers that collected emitted PM10. Of the surface treatments evaluated, application of water (6.4 mm) and hay (723 g/m2) exhibited the greatest percentage reduction in PM10 emission potential (69% and 77%, respectively) compared with the untreated manure layer. Computational fluid dynamics (CFD) was applied to predict airflow and particle collection by a row of trees (2.2 m high × 1.6 m wide). Predicted particle collection efficiencies generally agreed with published data and ranged from less than 1% for 0.875-µm particles to approximately 32% for 15-µm particles.

New emission legislation regarding air pollution control, as instructed by the Department of Environmental Affairs (DEA) to Eskom Generation Power Stations, implies a particulate emission limit of 100 mg/Nm3 for all existing power stations by 2015 and 50 mg/Nm3 for all new and existing power stations by the year 2020. Some of Eskom’s power stations which are equipped with Electrostatic Precipitators (ESP’s) were not designed for this stringent legislation. It is also experienced that ESP’s and coal quality in Eskom have deteriorated over time, resulting in the performance of the ESP’s not meeting the legislative requirements. Eskom is in the process of introducing various ESP enhancement projects to improve performance and aligning the operating philosophy to comply with the more stringent particulate emission legislation. An ESP efficiency test was conducted at Lethabo Power Station to determine the current state of the plant and performance. The results of the test were compared with the original design base specifications to determine the relevant deficiencies which contribute to high emissions and poor ESP performance. It was aimed to develop an ESP simulation model and validate the outputs with the test data. This study endeavours to demonstrate the greater impact on ESP performance when the ESP is operated outside the design specification. It is further aimed to demonstrate that a solution to the problem of high emissions is not only contributed by the variables within the ESP itself. This study is a coal to stack evaluation considering the ESP variables and the upstream conditions of the ESP that form part of the entire process. The intention of this study is to demonstrate the importance of operating an ESP at the designed parameters and highlight the significance of proper maintenance. It was learned that before any ESP enhancement technology can be implemented, the ESP and upstream conditions must be in accordance with design specifications. The implementation of an ESP enhancement technology will have no merit or justification on a unit that is being operated outside of its design specifications. The results obtained from the ESP simulation model correlated well with the ESP efficiency test data. The expectation of the model to assist operators and engineers to operate ESP’s according to the designer’s specifications was conceded. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

New emission legislation regarding air pollution control, as instructed by the Department of Environmental Affairs (DEA) to Eskom Generation Power Stations, implies a particulate emission limit of 100 mg/Nm3 for all existing power stations by 2015 and 50 mg/Nm3 for all new and existing power stations by the year 2020. Some of Eskom’s power stations which are equipped with Electrostatic Precipitators (ESP’s) were not designed for this stringent legislation. It is also experienced that ESP’s and coal quality in Eskom have deteriorated over time, resulting in the performance of the ESP’s not meeting the legislative requirements. Eskom is in the process of introducing various ESP enhancement projects to improve performance and aligning the operating philosophy to comply with the more stringent particulate emission legislation. An ESP efficiency test was conducted at Lethabo Power Station to determine the current state of the plant and performance. The results of the test were compared with the original design base specifications to determine the relevant deficiencies which contribute to high emissions and poor ESP performance. It was aimed to develop an ESP simulation model and validate the outputs with the test data. This study endeavours to demonstrate the greater impact on ESP performance when the ESP is operated outside the design specification. It is further aimed to demonstrate that a solution to the problem of high emissions is not only contributed by the variables within the ESP itself. This study is a coal to stack evaluation considering the ESP variables and the upstream conditions of the ESP that form part of the entire process. The intention of this study is to demonstrate the importance of operating an ESP at the designed parameters and highlight the significance of proper maintenance. It was learned that before any ESP enhancement technology can be implemented, the ESP and upstream conditions must be in accordance with design specifications. The implementation of an ESP enhancement technology will have no merit or justification on a unit that is being operated outside of its design specifications. The results obtained from the ESP simulation model correlated well with the ESP efficiency test data. The expectation of the model to assist operators and engineers to operate ESP’s according to the designer’s specifications was conceded. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014