Asian dust storm (ADS) not only increase the coarse particle concentrations, but also bring the fine and ultrafine particles to Taiwan. In this study, A PCA model was applied to identify the potential source categories, obtained through measuring ambient 10-500 nm particle number concentrations, size distributions and composition data, during an ADS and non-dust periods. The three factors estimated with rotational components during an ADS were vehicular emissions (52%), dust storm (24%), and primarily gasoline vehicles (12%). During non-dust periods, the three factors were vehicular emissions, secondary sulfate and nitrate (40%), combustion processes and traffic-related emissions (29%), and road dust (25%). In addition, vehicular emissions and road dust were the main sources (78%) during particulate matter episodes. The results showed that, along with wind direction and wind speed, PM composition and size distribution can be used to determine the locally dominant source categories, and to identify ADS episodes.

Water-emulsified diesel has proven itself as a technically sufficient improvement fuel to improve diesel engine fuel combustion emissions and engine performance. However, it has seldom been used in light-duty diesel engines. Therefore, this paper focuses on an investigation into the thermal efficiency and pollution emission analysis of a light-duty diesel engine generator fueled with different water content emulsified diesel fuels (WD, including WD-0, WD-5, WD-10, and WD-15). In this study, nitric oxide, carbon monoxide, hydrocarbons, and carbon dioxide were analyzed by a vehicle emission gas analyzer and the particle size and number concentration were measured by an electrical low-pressure impactor. In addition, engine loading and fuel consumption were also measured to calculate the thermal efficiency. Measurement results suggested that water-emulsified diesel was useful to improve the thermal efficiency and the exhaust emission of a diesel engine. Obviously, the thermal efficiency was increased about 1.2 to 19.9%. In addition, water-emulsified diesel leads to a significant reduction of nitric oxide emission (less by about 18.3 to 45.4%). However the particle number concentration emission might be increased if the loading of the generator becomes lower than or equal to 1800 W. In addition, exhaust particle size distributions were shifted toward larger particles at high loading. The consequence of this research proposed that the water-emulsified diesel was useful to improve the engine performance and some of exhaust emissions, especially the NO emission reduction. Implications: The accumulated test results provide a good basis to resolve the corresponding pollutants emitted from a light-duty diesel engine generator. By measuring and analyzing transforms of exhaust pollutant from this engine generator, the effects of water-emulsified diesel fuel and loading on emission characteristics might be more clear. Understanding reduction of pollutant emissions during the use of water-emulsified diesel helps improve the effectiveness of the testing program. The analyzed consequences provide useful information to the government for setting policies to curb pollutant emissions from a light-duty diesel engine generator more effectively.

Experiments were carried out to investigate filtration characteristics of an electrostatic precipitator (ESP) with alternating and direct electric field corona charger. Potassium Sodium Tartrate Tetrahydrate as the material was used to generate polydisperse submicron aerosols by using Constant Output Atomizer. The results indicated that the aerosol penetration through the ESP decreased as applied voltage increased. The maximum collection efficiency of either alternating or direct electric field was more than 98%, though the applied voltage of alternating electric field was higher than that of direct electric field. However, from the viewpoint of power consumption, the direct electric field had higher power consumption rate than alternating electric field at similar collection efficiency. For example, when the 0.2 µm particle penetration was about 4%, the power consumptions of alternating and direct electric field were 16 watt and 18 watt, respectively. Hence the separation quality of alternating electric field was better than that of direct electric field. Moreover, considerably lower ozone concentration was found in alternating electric field ESP, compared to direct electric field.

Selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) technique are widely used to control nitrogen oxides emissions. However, both techniques have a general shortcoming known as NH 3 slip.This research introduced the design of activated carbon in a circulating fluidized-bed with microwave system and developed an innovative de-NO x technique. The whole system demonstrated the capability and advantage of reducing reductant cost and continuous process. The experiments investigated microwave to regenerate activated carbon (AC) in order to increase adsorption and destruction efficiency while reducing energy consumption. In the NO x abatement process, activated carbon adsorbed NO and NO 2 and then utilized microwave heating technology to regenerate itself because of microwave's high energy utilization and strong penetration ability. The specific surface areas of AC increased from 673.03 to 834.52 (m 2 /g) when microwave power was increased from 0 to 550 W, respectively, in this study. Through increasing the specific surface area, the microwave treatment further improved the NO x adsorption capacity and rate.In consequence, the results indicated that destruction efficiency of NO and NO 2 at 200 ppm could reach about 80% with microwave power of 350 W and above 85% of 550 W. The destruction efficiency at 550 W for NO x was about 77%.

This study was focused on fuel energy efficiency and pollution analysis of different ratios of ethanol-gasoline blended fuels (E0, E3, E6, and E9) under different loadings. In this research, the experimental system consisted of a small engine generator, a particulate matter measurement system, and an exhaust gas analyzer system. Different fuels, unleaded gasoline, and ethanol-gasoline blends (E0, E3, E6, and E9) were used to study their effects on the exhaust gas emission and were expressed as thermal efficiency of the small engine generator energy efficiency. The results suggested that particle number concentration increased as the engine loading increased; however, it decreased as the ethanol content in the blend increased. While using E6 as fuel, the carbon monoxide (CO) concentration was less than other fuels (E0, E3, and E9) for each engine loading. The average of CO concentration reduction by using E3, E6, and E9 is 42, 86, and 83%, respectively. Using an ethanol-gasoline blend led to a significant reduction in exhaust emissions by approximately 78.7, 97.5, and 89.46% of the mean average values of hydrocarbons (HCs) with E3, E6, and E9 fuels, respectively, for all engine loadings. Using an ethanol-gasoline blend led to a significant reduction in exhaust emissions by approximately 35, 86, and 77% of the mean average values of nitrogen oxides (NO x ) with E3, E6, and E9 fuels, respectively, at each engine loading. The E6 fuel gave the best results of the exhaust emissions, and the E9 fuel gave the best results of the particle emissions and engine performance. The thermal efficiency of the small engine generator increased as the ethanol content in the blend increased and as the engine loading increased. INTRODUCTIONWith higher scale of consumption of nonrenewable fuels, the quest for an appropriate alternative fuel has gathered great momentum. The consequence to reduce pollutant emissions from petroleum-based engines has actuated the development and testing of several alternative fuels in recent years.Alcohols (e.g., ethanol, which is a colorless liquid with mild characteristic odor and can be produced from coal, natural gas, and biomass) have a high octane number and can be used as one of the practical alternative fuels. Furthermore, ethanol has a higher heat of vaporization than gasoline, which means it freezes the air, allows more mass to be drawn into the cylinder, and increases the power output. In addition, ethanol has antiknock characteristics that improve engine efficiency and give higher compression ratios.Ethanol contains an oxygen atom; therefore, it can be regarded as a partially oxidized fuel. 1,2 Because of this, it has a lower heating value and stoichiometric fuel-to-air ratio than gasoline. As a result, much more fuel is needed to obtain the same performance when ethanol or ethanolgasoline blends are used. 1,3,4 Ethanol has a higher octane number than gasoline, thus it can lead to operation at higher compression ratios and therefore improvement in power output, efficiency, and fuel con...