Reduction In PM Emissions Research Articles

Effects of low-pressure EGR on gaseous emissions and particle size distribution from a dual-mode dual-fuel (DMDF) concept in a medium-duty engine

The application of a low-temperature combustion concept, such as RCCI combustion under real engine operating conditions is extremely complex. However, the implementation of the dual-mode dual-fuel (DMDF) strategy allows operating in low-medium load with the RCCI combustion and in high load with dual-fuel diffusive combustion. This allows taking advantage of the benefits of RCCI combustion as the simultaneous reduction of PM and NOx emissions. However, there are still serious challenges that required to solve, such as the high-pressure rise rate and the excessive CO and HC emissions. In this sense, this work shows how the implementation and an adequate adjustment of the cooled LP-EGR rate significantly minimize these problems and also shows how the LP-EGR has a greater impact on the DMDF than on the CDC concept.This work has been performed in a modern medium-duty diesel engine fueled with standard gasoline and diesel fuels, with which a cooled LP-EGR loop has been coupled. A TSI Scanning Particle Sizer (SMPS 3936L75) was used to measure the particles size distribution and the Horiba MEXA-ONE-D1-EGR gas analyzer system to determine gaseous emissions. A parametric variation of the LP-EGR rate was experimentally performed to analyze the effect over each combustion process that encompasses the DMDF concept (fully premixed RCCI, highly premixed RCCI and dual-fuel diffusion) and its consequent impact on gaseous and particle emissions. In addition, results were compared against the CDC concept to state the benefits of the DMDF concept. Among the different results obtained, it can be highlighted that during the RCCI strategy the increase in LP-EGR rate provided a reduction in NOx emissions. Nonetheless, unlike that fully premixed RCCI in highly premixed RCCI combustion, the PM emissions increased with this increment in the LP-EGR rate, shifting the size distribution of particle toward larger sizes, but decreasing the HC and CO emissions. Finally, with the exception of the high HC and CO emissions in fully premixed RCCI, in all the combustion strategies of the DMDF concept, a reduction of the analyzed pollutants was observed when compared with the CDC mode.

A many-objective optimization of industrial environmental management using NSGA-III: A case of China’s iron and steel industry

Under the restriction of multiple industrial environmental targets, the difficulty of industrial environmental management, as a many-objective optimization problem, has increased significantly. As traditional optimization methods such as bottom-up models and commonly used intelligent algorithms have drawbacks in solving many-objective optimization problems, we introduce the third edition of Non-dominated Sorting Genetic Algorithm (NSGA-III) to the environmental management problem in China’s iron and steel industry. We build a many-objective optimization model to plan the application of the four types of decision variables: process equipment, cleaner production technologies, end-of-pipe treatment technologies and synergic technologies. In total, 7 objectives including the minimization of energy consumption, 5 types of pollutant reduction and economic cost are considered. In addition, to formulate final decision schemes, we adopt the Fuzzy C-means Clustering Algorithm to cluster the Pareto-optimal solutions. The results show that NSGA-III performs well in center distance, spacing metric, and computational efficiency. The Pareto-optimal solutions reflect that SO2 reduction target, is too strict, while others, such as energy conservation and PM emission reduction are too loose. Besides, we obtain four final decision schemes based on different objective preferences. In sum, the proposed methodology is proved to be capable of solving many-objective optimization problems and helping decision making in industrial environmental management.

Electrochemical NOx reduction and oxidation of HC and PM emissions from biodiesel fuelled diesel engines using electrochemically activated cell

ABSTRACTNOx emission is produced during combustion of fuels at high temperature. Excessive release of NOx causes several effects on living organisms and environment. In this work, the efforts to reduce NOx emission by developing electrochemically activated cells (EACs) for a diesel engine fuelled with diesel and biodiesel fuel are discussed. EAC technique is vital after treatment technology attempted in this work to simultaneous control of NOx, HC, and PM emissions. In this method, two types of EACs were developed. The CuO–YSZ electrolyte and CuO–YSZ electrolyte with BaO coating were developed and tested with diesel and biodiesel exhaust. Compared with diesel fuel, use of biodiesel fuel increased NOx emission by 11% and PM emission was slightly reduced with biodiesel, which was due to the presence of fuel bond oxygen content in biodiesel. The investigation has demonstrated low-temperature activation of the EACs at 250–350°C which was due to the addition of CuO to YSZ. In this work, maximum NOx reduction was achieved for CuO–YSZ cells with BaO NOx storage and the simultaneous control of HC and PM emission also was observed in this technique. NOx reduction by EAC is a vital technique and can be retrofitted with any diesel engine for emission reduction.

Performance and emissions of a compression-ignition direct-injected natural gas engine with shielded glow plug ignition assist

Performance and emissions experiments were conducted on a compression-ignition direct-injected natural gas engine (DING) equipped with a shielded glow plug ignition assist system. Tests were conducted at three different intake pressures (34.5 kPag, 68.9 kPag, 103.4 kPag), and four nominal (targeted) equivalence ratios (0.2, 0.3, 0.4, 0.5). CH4, NOx, CO and PM emissions were measured and analyzed, showing that emissions levels are influenced by the DING engine’s combustion modes and intake pressure. Premixed combustion which dominates at low equivalence ratios resulted in higher levels of CH4 and NOx emissions, while mixing-controlled combustion, which develops at higher equivalence ratios, resulted in elevated CO and PM levels. Higher intake pressure was found to improve all emissions levels. The most significant effect was the reduction of PM and CO emissions due to improved fuel charge mixing and air entrainment that results from a pressure-driven momentum increase of the engine’s air swirl field. Brake specific emissions and fuel consumption were estimated and compared against levels reported in the literature for dual-fuel port-injection, and High-Pressure Direct-Injection (HPDI) natural gas engines. The most significant finding was that the DING engine exhibits lower fuel consumption and PM emissions levels when compared to values reported in the literature for HPDI engines. The PM emissions advantage was attributed to a higher proportion of premixed combustion and the absence of a diesel pilot in DING engine operation. Lastly, PM size distributions were analyzed, showing that the DING engine produces PM that is smaller than PM of a conventional diesel engine, but similar to the PM reported in the literature for HPDI engines.

Oxidized biodiesel as a cetane improver for diesel–biodiesel–ethanol mixtures in a vehicle engine

Most work in literature claim that the addition of biodiesel into diesel usually increases NOx emissions of compression ignition engines. Ethanol can be added to diesel and biodiesel blends in order to reduce NOx and also to increase the renewable fraction of the mixture. In this work oxidized biodiesel (induction period of 0 h) was evaluated as a cetane improver for blends containing diesel, biodiesel and ethanol so that the negative effects from the high resistance to auto-ignition (low cetane number) of ethanol can be mitigated. 13 blends of diesel, biodiesel, oxidized biodiesel and ethanol as well as an additivated mixture using 2-ethyl hexyl nitrate (2-EHN) were tested in a vehicle equipped with a four cylinders, turbo charged, common rail, diesel engine. The volumetric percentage of ethanol in the mixtures of diesel, biodiesel and ethanol was 0, 2, 4 and 6%, while the biodiesel volumetric content was 0, 5 and 35%. The results have revealed no significant changes in the wheel power for small percentages of ethanol and biodiesel. The use of 20% of oxidized biodiesel has proved to be an interesting additive for cetane improvement enabling quicker responses in acceleration and higher wheel power in comparison to the commercial additive (2-EHN). Emission tests using a mixture containing 90% of conventional diesel, 4% ethanol, 5% biodiesel and 1% oxidized biodiesel have shown reduction in NOx and PM emissions in comparison to conventional diesel.

Development of reduction scenarios for criteria air pollutants emission in Tehran Traffic Sector, Iran

Transport-related pollution as the main source of air pollution must be reduced in Tehran mega-city. The performance of various developed scenarios including BAU (Business As Usual) as baseline scenario, ECV (Elimination of carburetor equipped Vehicle), NEM (New Energy Motorcycles), HES (Higher Emission Standard), VCR (Vehicle Catalyst Replacement), FQE (Fuel Quality Enhancement), DPF (Diesel Particulate Filter) and TSA (Total Scenarios Aggregation) are evaluated by International Vehicle Model up to 2028. In the short term, the ECV, VCR, and FQE scenarios provided high performance in CO, VOCs and NOx emissions control. Also FQE has an excellent effect on SOx emission reduction (86%) and DPF on PM emissions (20%). In the mid-term, the VCR, ECV, and FQE scenarios were presented desirable mean emission reduction on CO, VOCs, and NOx. Moreover, NOx emission reduction of DPF scenario is the most common (14%). Again FQE scenario proves to have great effect on SOx emission reduction in mid-term (86%), DPF and HES scenarios on PM (DPF: 49% and HES: 17%). Finally for the long term, VCR, ECV, FQE, and NEM scenarios were shown good performance in emission control on CO, VOCs and NOx. For SOx only FQE has a good effect in all time periods (FQE: 86%) and DPF and HES scenarios have the best effect on PM emission reduction respectively (DPF: 51% and HES: 27%) compared with BAU scenario. However, DPF scenario increases 12% SOx emission in long-term (2028). It can be generally concluded that VCR and ECV scenarios would achieve a significant reduction on gaseous pollutants emission except for SOx in general and FQE scenarios have desirable performance for all gaseous pollutants in the short term and also for SOx and VOCs in long term. In addition, the DPF and HES would be desirable scenario for emission control on PM in Tehran Traffic Sector.

Estimation of the Effectiveness of the Current Policies on Coal-related Air Pollution Control

China has been experiencing severe haze pollution mainly due to its fast economic growth and large amount of coal consumption. To deal with the problems, Chinese government has issued a series of policies to control main air pollutants emission. In this paper, the effectiveness of the policies to control the major four coal-consuming sectors, which are coal-fired power plants, coal-related industrial processes, coal-fired boilers and household coal consumption, were evaluated. The main air pollutants emission reduction was estimated and the air quality improvement was simulated using the WRF-CMAQ model. The results showed that by 2017, the emissions of SO2, NOx and primary PM from the four sectors will decrease by 1.37 million tons, 1.28 million tons and 1.55 million tons, respectively, which are 7.4%, 6.9% and 10.1%, compared with 2015. Consequently, the annual average concentration of PM2.5 will decrease by 3ug/m3, a drop of 6%. Implementation of the ultra-low emission standards in the coal-fired power plants is the most effective measures to reduce SO2 and NOx emission, while installation of dust removal facilities in coal related industrial processes contributes most to primary PM emission reduction.

Chemical characteristics of PM2.5 during summer at a background site of the Yangtze River Delta in China

With rapid economic development and urbanization, particular attention has been paid to atmospheric chemical studies in the Yangtze River Delta in China. PM2.5 samples were collected by a MiniVol™ air sampler in summer time at a background site of the Yangtze River Delta in China. Carbonaceous components, i.e., OC and EC, levoglucosan and water-soluble inorganic ions, including sulfate, nitrate, ammonium, etc., were quantified. The average concentration of PM2.5 in summer at Lin'an was 30.19±8.86μgm−3, lower than previous studies reported, confirming that air pollution in China is improving, e.g., by emission control measures and subsequent reduction in PM emissions in China. Investigating the relationship among sulfate, nitrate and ammonium showed that SO42− existed as (NH4)2SO4, while NO3− may have been present as NaNO3 and KNO3. Based on molecular tracers, synoptic data as well as air mass back trajectory analysis, it was revealed that regional transport and stable synoptic conditions both play an important role in controlling the variations of aerosol chemical components. The comparison of chemical species between clean and hazy days showed that secondary organic and inorganic aerosols have different production processes. Secondary organic carbon (SOC) was much more important during clean days, while secondary inorganic aerosol species were readily produced and consequently became more important during polluted periods in Lin'an during summer time.

Comparison on the effect of using diesel fuel and waste cooking oil biodiesel as pilot fuels on the combustion, performance and emissions of a LPG-fumigated compression-ignition engine

The present investigation was conducted on a 4-cylinder diesel engine fueled with either pilot diesel, or pilot waste cooking oil biodiesel (WCOB), and fumigated liquified petroleum gas (LPG) at three loads. The LPG addition is expressed in terms of a LPG power substitution percentage (LPSP), ranging from 10 to 30% at each load. This investigation aimed at comparing the combustion, performance and emissions characteristics between the two types of dual-fuel operation, one using pilot diesel and the other using pilot WCOB, with emphasize on the particulate mass and number concentrations. The results show that the combustion characteristics, involving heat release rate, peak cylinder pressure, start of combustion, combustion duration and CA50 of the LPG-fumigated engine, are modestly influenced by the type of pilot fuel in use. The impacts of the LPSP on the brake specific fuel consumption and brake thermal efficiency are negative at low load and positive at high load, for both types of pilot fuel. Regarding the emissions, it can be concluded that both types of dual-fuel operation can lead to reduction in both NOx and PM emissions, with LPG-Diesel operation being more effect in reducing NOx emissions while LPG-WCOB operation more effective in reducing particulate emissions.

Development of novel alternative biodiesel fuels for reducing PM emissions and PM-related genotoxicity

This paper intend to investigate the effects of biodiesel fuel blends comprising of waste-cooking oil and butanol-diesel (B10W10–B10W40) under steady-state conditions. Both particulate organic carbon (OC) and PM including PM2.5 and PM10 significantly decreased with the increasing percentage of biodiesel fuel blends. The fuel blend of B10W40 also demonstrated the most effective function in reducing the emissions of PM10 and PM2.5 in the volume by 59.4% and 57.7%, respectively. Moreover, the emissions of nitrogen oxides decreased with the blending of B10W10-B10W40 (13.9–28.5%), while the brake specific fuel consumption was substantially increased (5.69–13.4%). The overall biological toxicity of PM10 generated from the fuel tested in this study was determined according to Single Cell Gel Electrophoresis assay in human alveolar basal epithelial A549 cells and micronucleus assay in CHO-K1 cells. In addition, the volume of more than 20% waste-cooking oil (B10W20 and B10W40) significantly reduced diesel-induced genotoxicity in lung cells and micronucleus formation in CHO-K1 cells. Collectively, these results indicated that biodiesel fuel blends with the butanol could be a potential alternative fuels for diesel engines because of its substantial property with a significant reduction of the PM-related genotoxicity and the emissions of PM, particulate OC, and NOX.

Macadamia Biodiesel as a Sustainable and Alternative Transport Fuel in Australia

Abstract The study investigated the prospect of Macadamia biodiesel as a sustainable and alternative fuel for diesel engine in the transport sector in Australia. The crude vegetable oil is converted to biodiesel by the transesterification reaction with potassium methoxide as a catalyst at 60 °C for one hour. The fatty acid composition and fuel properties of the converted biodiesel are tested under the ASTM and EN standards and compared those with the properties of Ultra-low Sulphur diesel (ULSD). A 4 cylinder, four strokes, DI diesel engine performance and emission characteristics were studied using B5 (5% biodiesel + 95% ULSD by vol.) and B20 (20% biodiesel + 80% ULSD by vol.) blends. The experiment was conducted at full load condition by varying engine speed from 1200 rpm to 2400 rpm. The study examined the brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) as engine performance parameters and CO, CO 2 , HC, PM, NO x , and EGT as emission parameters and compared these with results of ULSD. The study found minimum BSFC and maximum BTE at 1600 rpm engine speed. The result reveals that Macadamia biodiesel has higher BSFC, about 5% (B5) to 10% (B20) and lower BTE, about 4.5% (B5) to 6.8% (B20) throughout the range of engine speed. Significant reduction in CO, HC, and PM emissions were found. More specifically, an average reduction of 26% (B5) to 40% (B20) in CO; about 9% (B5) to 31% (B20) in HC; 15% (B5) to 33% (B20) in PM emission were found compared to ULSD. However, the higher EGT of the biodiesel blends increases NOx emission, about 21% to 27% compared to ULSD. Further study on tribological characteristics of Macadamia biodiesel is recommended before any commercial application can be made.

Effect of split fuel injection and EGR on NOx and PM emission reduction in a low temperature combustion (LTC) mode diesel engine

In this study, an advanced combustion concept ‘premixed charge compression ignition’ (PCCI) has been explored for application in diesel engines. PCCI combustion is a single-stage combustion process, in which a large fraction of fuel burns in premixed combustion phase resulting in relatively lower in-cylinder temperatures compared to compression ignition (CI) combustion. However at high loads, PCCI combustion results in severe knocking and higher oxides of nitrogen (NOx) emissions. This limits the applicability of this combustion concept up to medium engine loads. This limitation of PCCI combustion can be resolved by altering in-cylinder pressure-temperature history at the time of fuel injection. This can also be resolved by deploying suitable split fuel injection strategy and exhaust gas recirculation (EGR), which control combustion events such as start of combustion (SoC) and combustion phasing, leading to lower knocking and NOx emissions. To investigate the effects of various split injection strategies and EGR on PCCI combustion, engine experiments were conducted at different start of main injection (SoMI) timings (12, 16, 20 and 24° bTDC), start of pilot injection (SoPI) timings (30, 35 and 40° bTDC) and EGR rates (0, 15 and 30%). This study also included detailed particulate characterization such as particulate number-size distribution using an engine exhaust particle sizer (EEPS) and particulate bound trace metal analysis by inductively coupled plasma-optical emission spectrophotometry (ICP-OES). PCCI combustion was found to be superior at 35° bTDC SoPI timing and 15% EGR. At retarded SoPI timing (30° bTDC), PCCI combustion resulted in slightly higher NOx and particulate emissions, however at too advanced SoPI timing (40° bTDC), PCCI combustion showed relatively inferior engine performance. Application of EGR improved PCCI combustion and emission characteristics, however at high EGR, PCCI combustion resulted in inferior engine performance due to reduction in bulk in-cylinder temperatures. Overall, this study showed that PCCI combustion stability, knocking and NOx emissions can be optimized by selecting suitable combination of SoMI and SoPI timings, and EGR rate.

Measurement Method and Reduction of PM Emissions from Marine Diesel Engines

Measurement Method and Reduction of PM Emissions from Marine Diesel Engines

Ship emission reduction effect evaluation of air pollution control countermeasures

Abstract In this paper, the methods of waterborne transport data mining, emission reduction scenario analysis and ship emission calculation according to engine power are combined to establish models of ship emission inventory, reduction trend analogy, and investment effect analysis, which can achieve quantitative evaluations of ship emissions inventories, classification ratios and emission reduction effects of different scenarios, including to calculate air pollutant emissions of various kinds of ships in different areas and working conditions; to predict cargo turnovers of inland water, domestic coastal and marine ships and foreign marine ships; to analyze analogically emissions and reductions according to growths of national GDP and waterborne transport; to estimate the ship load tons and numbers of different kinds of vessels, as well as reductions per investment or operating costs of reduction facilities on board. The evaluation results show that the total emission of CO 2 in China’s inland water and coastal areas from all kinds of transport ships and in other regions from domestic marine ships reached a peak in about 2020 to 2027 when fuel consumption per unit turnover in 2020 decrease by 27%%~45% compared with that in 2005 and then fell 20%~25% by 2030. In the scenarios when NOx and SOx emission reduction targets designed in accordance with relevant international conventions and domestic laws and regulations, NOx, SOx, PM emission reduction effects in China’s from all kinds of transport ships are significant, while the effects were limited or very limited if the reduction were only implemented 50% or 25% of designed targets. According to emission inventory and classification ratios, the control priority should be given to the larger emission sources, in turn: host engines of transport ships in navigation areas, auxiliary engines of transport ships when mooring or berthing in port areas, and the auxiliary operation ships in port areas, and comprehensive prevention and control countermeasures should be taken for effective control of emissions from inland water ships, foreign marine and domestic coast and marine ships in coastal areas.

Model based burnt gas fraction controller design of diesel engine with VGT/Dual loop EGR system

-Recently, regulation of NOx and PM emission in diesel engines has become stricter and the EGR system has been expanded into a dual loop EGR system to increase EGR rate as well as to utilize exhaust gas strategically. In terms of engine combustion characteristics, burnt gas fraction is becoming an important factor of solving the NOx and PM emission reduction problem more efficiently but conventional controller focused only pressure and air flow rate targets. Unlike the previous studies, this paper describes a model based burnt gas fraction control structure for a diesel engine with a dual loop EGR and a turbocharger. Feedforward control inputs based on burnt gas fraction states aids in the precise control of diesel engines, especially in transient states by considering coupled behavior within the system. For the controller validation, a control oriented reduced order model of a diesel engine air management system is established to simplify the control input computation and its stability is proved by analysing the internal dynamics stability. Then, a sliding mode controller is designed and controller robustness at certain operating points is validated using an HiLS bench.

Experimental Investigation of Homogeneous Charge Induced Ignition (HCII) with Low-Pressure Injection to Reduce PM Emissions in a Heavy-Duty Engine

Experimental Investigation of Homogeneous Charge Induced Ignition (HCII) with Low-Pressure Injection to Reduce PM Emissions in a Heavy-Duty Engine

Particulate Size Distribution from Diesel–Dimethyl Ether Dual Fuel Premixed Compression Ignition Combustion Engine

AbstractParticulate matter (PM) emission has been a concern in recent years because of its impact on the atmospheric environment and human health. Recently the dual-fuel premixed charge compression ignition (PCCI) combustion strategy has become a popular option of reducing PM emissions from compression-ignition engines. In the current paper, the variations of PM emissions from the diesel–dimethyl ether (DME) dual-fuel premixed charge compression ignition combustion engine are investigated under the various input DME energy ratios, diesel injection timings, speeds, and loads. An electrical low pressure impactor (ELPI) is used for characterizing the particle number/mass and size distribution. The particulate number and mass concentrations for DME-diesel dual-fuel premixed charge compression ignition operation are lower than those of conventional direct-injection compression ignition (DICI) operation and reduce with a rise of port DME ratio under all operating conditions because of oxygen content and no C-C ...

Effective reduction of in-cylinder peak pressures in Homogeneous Charge Compression Ignition Engine – A computational study

HCCI mode of combustion is known for simultaneous reduction of NOx and PM emissions besides yielding low specific fuel consumption. The nature of volumetric combustion of HCCI engine leads to the development of high peak pressures inside the combustion chamber. This high peak pressures may damage the engine, limiting the HCCI engine life period and thus demands sturdy designs. In this study an attempt is made to analyze computationally the effect of induction swirl in reducing the peak pressures of a HCCI engine under various operating parameters. For the study, specifications of a single cylinder 1.6L, reentrant piston bowl diesel engine are chosen. For the computational analysis ECFM-3Z model of STARCD is considered. This model is suitable to analyze the combustion processes in SI and CI engines. As HCCI engine is a hybrid version of SI and CI engines, ECFM-3Z model with necessary modifications is used to analyze the peak pressures inside the combustion chamber. The ECFM-3Z model for HCCI mode of combustion is validated with the existing literature to make sure that the results obtaining are accurate. Numerical experiments are performed to study the effect of compression ratio, equivalence ratio, exhaust gas recirculation and boost pressure under different swirl ratios in reducing the in-cylinder peak pressures. The results showed that swirl ratio has a considerable impact in limiting the peak pressures of HCCI engine. The analysis resulted in achieving about 21% reduction in peak pressures are achieved when a swirl ratio of 4 with 30% EGR is adopted when compared to a swirl ratio of 1 with 0% EGR. The study revealed that out of the four operating parameters selected, lower compression ratios, higher EGR concentrations, lower equivalence ratios, lower boost pressures and higher swirl ratios are favorable in reducing the peak pressures.

The Simultaneous Reduction of NOx and PM Using Ultra-Cooled EGR and Retarded Injection Timing in a Diesel Engine

Now-a-days, diesel engines are more popular over gasoline engines due to their undisputed benefit of fuel economy and higher torque output. However, meeting the stringent emission norms without affecting fuel economy is a major challenge with diesel engines. In this paper, optimization of various parameters like injection parameters, compression ratio (CR) and amount of ultra-cooled exhaust gas recirculation (EGR) has been done for a variable CR (VCR) engine, to achieve low-temperature combustion (LTC) mode by which simultaneous reduction of NOx and soot may be obtained. Taguchi analysis was employed to carry out minimum number of experimental runs and still get the essence of large number of test cases. Effect of those parameters on engine performance and exhaust emissions has also been studied with the help of signal-to-noise (SN) ratio analysis. Results of SN ratio analysis indicate that injection timing, CR and ultra-cooled EGR are the dominant factors while the effect of injection pressure, in range of study, is not much significant for chosen response variables. Flatter and wider HRR traces, hence simultaneous reduction in NOx and PM emissions has been observed for runs having optimized input parameters. NOx and soot found to be reduced by 98% and 60%, respectively, with an increase in brake thermal efficiency (BTE) by 5%. Higher values of HC and CO emissions were found for runs with optimized parameters, but these can be easily reduced by using a catalytic converter, a simple device.

Particulate Emissions from a Beef Cattle Feedlot Using the Flux-Gradient Technique

Data on air emissions from open-lot beef cattle () feedlots are limited. This research was conducted to determine fluxes of particulate matter with an aerodynamic diameter ≤10 μm (PM) from a commercial beef cattle feedlot in Kansas using the flux-gradient technique, a widely used micrometeorological method for air emissions from open sources. Vertical PM concentration profiles and micrometeorological parameters were measured at the feedlot using tapered element oscillating microbalance PM samplers and eddy covariance instrumentations (i.e., sonic anemometer and infrared hygrometer), respectively, from May 2010 through September 2011, representing feedlot conditions with air temperatures ranging from -24 to 39°C. Calculated hourly PM fluxes varied diurnally and seasonally, ranging up to 272 mg m h, with an overall median of 36 mg m h. For warm conditions (air temperature of 21 ± 10°C), the highest hourly PM fluxes (range 116-146 mg m h) were observed during the early evening period, from 2000 to 2100 h. For cold conditions (air temperature of -2 ± 8°C), the highest PM fluxes (range 14-27 mg m h) were observed in the afternoon, from 1100 to 1500 h. Changes in the hourly trend of PM fluxes coincided with changes in friction velocity, air temperature, sensible heat flux, and surface roughness. The PM emission was also affected by the pen surface water content, where a water content of at least 20% (wet basis) would be sufficient to effectively reduce PM emissions from pens by as much as 60%.