Particulate Matter Abatement Research Articles

Evaluating the oxidation kinetic parameters of gasoline direct injection soot from thermogravimetric analysis experiments

The abatement of particulate matter in gasoline direct injection (GDI) engines requires the use of particulate filters. In turn, the optimisation of their regeneration is based on a deep knowledge of the soot oxidation behaviour. The determination of the intrinsic kinetic parameters of GDI soot is explored based on thermogravimetric analysis (TGA) and reaction rate modelling. New understanding on the oxidation of GDI soot is provided enabling an accurate prediction in a wide range of temperature and O2 concentration. Firstly, the dependence of the soot reaction order on the boundary conditions is discussed. The analysis of the Arrhenius equation parameters reveals variable O2 reaction order. It leads to consider the effect of mass transfer and adsorption (Langmuir and Dubinin-Radushkevich isotherms) as reaction rate limiters. Combined with the soot reaction order approach, the prediction ability of the proposed model is assessed in an extended range of isothermal and non-isothermal TGA experiments.

An Overview on the Catalytic Materials Proposed for the Simultaneous Removal of NOx and Soot.

Vehicular pollution has become a major problem in urban areas due to the exponential increase in the number of automobiles. Typical exhaust emissions, which include nitrogen oxides (NOx), hydrocarbons (HC), carbon monoxide (CO), soot, and particulate matter (PM), doubtless have important negative effects on the environment and human health, including cardiovascular effects such as cardiac arrhythmias and heart attacks, and respiratory effects such as asthma attacks and bronchitis. The mitigation measures comprise either the use of clean alternative fuels or the use of innovative technologies. Several existing emission control technologies have proven effective at controlling emissions individually, such as selective catalytic reduction (SCR) and lean NOx trap (LNT) to reduce NOx and diesel particulate filter (DPF) specifically for PM abatement. These after-treatment devices are the most profitable means to reduce exhaust emissions to acceptable limits (EURO VI norms) with very little or no impact on the engine performances. Additionally, the relative lack of physical space in which to install emissions-control equipment is a key challenge for cars, especially those of small size. For this reason, to reduce both volume and cost of the after-treatment devices integrated catalytic systems (e.g., a sort of a “single brick”) have been proposed, reducing both NOx and PM simultaneously. This review will summarize the currently reported materials for the simultaneous removal of NOx and soot, with particular attention to their nature, properties, and performances.

Experimental Study on the Flow Field of Particles Deposited on a Gasoline Particulate Filter

The abatement of particulate matter in gasoline vehicle exhaust has prompted the development of gasoline particulate filters (GPFs). The spatial distribution of the deposited particles inside a GPF has profound implications for its regeneration behavior, ash-induced aging, and multiscale modeling efforts. The connection cones will affect the flow into the monolith and the package structure needed to meet the system space requirements. In this paper, nonuniform rational B-splines (NURBSs) were applied to the cone design to optimize the flow uniformity and particle distribution inside a gasoline particulate filter. NURBS and conventional cones were manufactured using 3D printing, and the velocity profiles and pressure drops were measured under the loading of synthetic particles. The results shows that the cone shape will influence the pressure drop and the velocity profile, which is evaluated as the uniformity index. The test results indicate that better performance is achieved when using the NURBS cone, especially at low particle loads. The results also show that the cone shape (which determines the velocity profile) influences the particle deposition distribution, although the apparent pressure drops are similar. These results are important for exhaust aftertreatment system (EATS) design and optimization, where the NURBS cone can improve flow uniformity, which causes better particle deposition distribution and lower pressure drop.

New scrubber for air purification: abatement of particulate matter and treatment of the resulting wastewater

The present paper deals with an innovative scrubber (air pollution abatement) used to remove particulate matter and other pollutants from air. Air pollution abatement scrubbers were placed in different urban areas and in industrial production sites. In particular, the results obtained in one fiberglass production facility showed a reduction in particulate matter of 46.3–99.9% in the size range 0.50–0.00 µm throughout the experimentation period. The aqueous solutions coming from the scrubbers, placed in different sites, were collected, analyzed and treated in order to regenerate the water and make it available for the periodic refilling of the scrubber’s tanks. Coagulation, precipitation, carbon adsorption and Fenton processes were applied in order to design a suitable integrated process able to treat all the samples coming from the scrubbers. The reduction in total suspended solids, total dissolved solids, phenols and chemical oxygen demand was higher than 85% by the Fenton process, demonstrating that water is completely recoverable and reusable. Alternatively, the treated water can be discharged into a surface water body. Based on the results from the experimental campaign, a mobile plant was designed in order to treat such wastewater. Depending on the physicochemical parameters of the wastewater, specific treatments can be chosen and carried out by such mobile plant.

Incentive policy for reduction of emission from ships: A case study of China

Particulate matter (PM) emissions from ships in ports are a major contributor to air pollution and smog in port cities. The issue of how to reduce PM emissions has become a critical concern for port city residents and governments. This paper establishes an incentive policy to reduce PM emissions from ships in ports. Using a Panamax bulk carrier as a case study, eight alternative approaches that could be adopted by shipping companies are compared and their operational benefits are estimated. By restricting the analysis to emission control areas (ECAs), the net present value (NPV) model shows that the diesel particulate filter (DPF) is the most advantageous approach with the highest NPV, while the exhaust gas scrubber (EGS) approach is the most economically inefficient. Meanwhile, due to DPF's excellent performance in PM abatement, it is suggested that governments should prioritize the DPF approach when promoting the application of emission reduction technologies. From the perspective of social welfare, a positive social benefit of about US $20,000 will be generated over the life cycle of a ship. However, a low government pricing in China will reduce shipping companies’ operational performance as the emission control zone (ECZ) gradually expands. As a result, an appropriate subsidy scheme is necessary to encourage shipping companies to apply emission reduction technologies.

Variations in the chemical composition of the submicron aerosol and in the sources of the organic fraction at a regional background site of the Po Valley (Italy)

Abstract. Fine particulate matter (PM) levels and resulting impacts on human health are in the Po Valley (Italy) among the highest in Europe. To build effective PM abatement strategies, it is necessary to characterize fine PM chemical composition, sources and atmospheric processes on long timescales (> months), with short time resolution (< day), and with particular emphasis on the predominant organic fraction. Although previous studies have been conducted in this region, none of them addressed all these aspects together. For the first time in the Po Valley, we investigate the chemical composition of nonrefractory submicron PM (NR-PM1) with a time resolution of 30 min at the regional background site of Ispra during 1 full year, using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) under the most up-to-date and stringent quality assurance protocol. The identification of the main components of the organic fraction is made using the Multilinear-Engine 2 algorithm implemented within the latest version of the SoFi toolkit. In addition, with the aim of a potential implementation of ACSM measurements in European air quality networks as a replacement of traditional filter-based techniques, parallel multiple offline analyses were carried out to assess the performance of the ACSM in the determination of PM chemical species regulated by air quality directives. The annual NR-PM1 level monitored at the study site (14.2 µg m−3) is among the highest in Europe and is even comparable to levels reported in urban areas like New York City and Tokyo. On the annual basis, submicron particles are primarily composed of organic aerosol (OA, 58 % of NR-PM1). This fraction was apportioned into oxygenated OA (OOA, 66 %), hydrocarbon-like OA (HOA, 11 % of OA) and biomass burning OA (BBOA, 23 %). Among the primary sources of OA, biomass burning (23 %) is thus bigger than fossil fuel combustion (11 %). Significant contributions of aged secondary organic aerosol (OOA) are observed throughout the year. The unexpectedly high degree of oxygenation estimated during wintertime is probably due to the contribution of secondary BBOA and the enhancement of aqueous-phase production of OOA during cold months. BBOA and nitrate are the only components of which contributions increase with the NR-PM1 levels. Therefore, biomass burning and NOx emission reductions would be particularly efficient in limiting submicron aerosol pollution events. Abatement strategies conducted during cold seasons appear to be more efficient than annual-based policies. In a broader context, further studies using high-time-resolution analytical techniques on a long-term basis for the characterization of fine aerosol should help better shape our future air quality policies, which constantly need refinement.

Abatement of particulate matter and SO2 emission by ships

Abatement of particulate matter and SO2 emission by ships

Costs and benefits of ammonia and particulate matter abatement in German agriculture including interactions with greenhouse gas emissions

The abatement of ammonia (NH3) and particulate matter (PM) emissions in agriculture reduces damages to human health and biodiversity and provides benefits for society, but also imposes costs on farmers. As NH3 and PM emissions partly originate from the same activities as greenhouse gases, interactions may exist between NH3 and PM emission abatement and greenhouse gas emissions. This study is aimed at estimating the costs and benefits of NH3 and PM emission abatement measures, considering interactions with agricultural greenhouse gas emissions in Germany. We combined an economic-ecological farm model for estimating emission reductions and abatement costs with an integrated environmental impact assessment model for estimating the benefits for human health and biodiversity, with applications to three Federal States in Germany. We reasoned that benefits exceed costs and that synergies with greenhouse gas reduction exist. All NH3 and PM emission abatement measures affected greenhouse gases. In crop production, conservation tillage increased farmers' gross margins and reduced both PM emissions and, via soil carbon sequestration, also greenhouse gas emissions. The benefits depended on the soil type and its carbon sequestration potential, which differ across regions. The substitution of urea fertiliser for calcium ammonium nitrate reduced both NH3 and greenhouse gas emissions. In livestock production, the measures with the highest net benefits were chemical washers for exhaust-air purification, injection or cultivator manure application and concrete manure storage cover. Low-protein pig feeding increased farmers' gross margins and also achieved high net benefits, with the benefits of greenhouse gas emission reduction exceeding those of NH3 emission reduction. Low-protein poultry feeding and biofilters for air purification yielded negative net benefits and were therefore not recommended for implementation. The results confirm interactions of NH3 and PM emission abatement measures with greenhouse gas emissions and suggest that all relevant emission types be integrated in an analysis. Air pollution abatement and climate change mitigation have mainly been addressed in separate policies. Our results suggest that these policies are better integrated so as to stimulate synergies and to define the appropriate ambition level of emission reduction targets.

Concentration, size, and density of total suspended particulates at the air exhaust of concentrated animal feeding operations

Total suspended particulate (TSP) samples were seasonally collected at the air exhaust of 15 commercial concentrated animal feeding operations (CAFOs; including swine finishing, swine farrowing, swine gestation, laying hen, and tom turkey) in the U.S. Midwest. The measured TSP concentrations ranged from 0.38 ± 0.04 mg m−3 (swine gestation in summer) to 10.9 ± 3.9 mg m−3 (tom turkey in winter) and were significantly affected by animal species, housing facility type, feeder type (dry or wet), and season. The average particle size of collected TSP samples in terms of mass median equivalent spherical diameter ranged from 14.8 ± 0.5 µm (swine finishing in winter) to 30.5 ± 2.0 µm (tom turkey in summer) and showed a significant seasonal effect. This finding affirmed that particulate matter (PM) released from CAFOs contains a significant portion of large particles. The measured particle size distribution (PSD) and the density of deposited particles (on average 1.65 ± 0.13 g cm−3) were used to estimate the mass fractions of PM10 and PM2.5 (PM ≤10 and ≤2.5 μm, respectively) in the collected TSP. The results showed that the PM10 fractions ranged from 12.7 ± 5.1% (tom turkey) to 21.1 ± 3.2% (swine finishing), whereas the PM2.5 fractions ranged from 3.4 ± 1.9% (tom turkey) to 5.7 ± 3.2% (swine finishing) and were smaller than 9.0% at all visited CAFOs. This study applied a filter-based method for PSD measurement and deposited particles as a surrogate to estimate the TSP’s particle density. The limitations, along with the assumptions adopted during the calculation of PM mass fractions, must be recognized when comparing the findings to other studies.Implications: The concentration, size, and density of TSP samples varied greatly with animal species, housing facility type, feeder type, and season, suggesting that PM emission data derived from limited measurements may not be readily applied to estimate the overall emission from concentrated animal feeding operations (CAFOs). This study also affirmed that particles released from CAFOs is of relatively high density (~1.65 g cm−3) and with diameter mostly larger than 10 µm, indicating that regular PM abatement devices, such as cyclones, fabric filters, or even a simple downward-facing exhaust duct, may be employed to mitigate the TSP emission with acceptable efficiency.

Performance evaluation of non-thermal plasma on particulate matter, ozone and CO2 correlation for diesel exhaust emission reduction

This study is seeking to investigate the effect of non-thermal plasma technology in the abatement of particulate matter (PM) from the actual diesel exhaust. Ozone (O3) strongly promotes PM oxidation, the main product of which is carbon dioxide (CO2). PM oxidation into the less harmful product (CO2) is the main objective whiles the correlation between PM, O3 and CO2 is considered. A dielectric barrier discharge reactor has been designed with pulsed power technology to produce plasma inside the diesel exhaust. To characterise the system under varied conditions, a range of applied voltages from 11kVPP to 21kVPP at repetition rates of 2.5, 5, 7.5 and 10kHz, have been experimentally investigated. The results show that by increasing the applied voltage and repetition rate, higher discharge power and CO2 dissociation can be obtained. The PM removal efficiency of more than 50% has been achieved during the experiments and high concentrations of ozone on the order of a few hundreds of ppm have been observed at high discharge powers. Furthermore, O3, CO2 and PM concentrations at different plasma states have been analysed for time dependence. Based on this analysis, an inverse relationship between ozone concentration and PM removal has been found and the role of ozone in PM removal in plasma treatment of diesel exhaust has been highlighted.

Will PM control undermine China’s efforts to reduce soil acidification?

China’s strategies to control acidifying pollutants and particulate matter (PM) may be in conflict for soil acidification abatement. Acidifying pollutant emissions are estimated for 2005 and 2020 with anticipated control policies. PM emissions including base cations (BCs) are evaluated with two scenarios, a base case applying existing policy to 2020, and a control case including anticipated tightened measures. Depositions of sulfur (S), nitrogen (N) and BCs are simulated and their acidification risks are evaluated with critical load (CL). In 2005, the area exceeding CL covered 15.6% of mainland China, with total exceedance of 2.2 Mt S. These values decrease in the base scenario 2020, implying partial recovery from acidification. Under more realistic PM control, the respective estimates are 17.9% and 2.4 Mt S, indicating increased acidification risks due to abatement of acid-neutralizing BCs. China’s anthropogenic PM abatement will have potentially stronger chemical implications for acidification than developed countries.

Climate policy in Western Europe and avoided costs of air pollution control

Abstract Abatement of CO2 emissions will be accompanied by reduced air pollutant emissions such as particulate matter (PM), SO2, and NOx. This, in turn, will reduce the need for end of pipe (EOP) pollution control technologies to meet future air quality targets. This dynamic could put more stringent air quality goals within reach, and increase the political feasibility of climate policy. This paper presents a CGE model that has been modified to include the emissions and EOP abatement of PM, SO2, and NOx from stationary sources in the EU-17. Emissions of pollutants are modeled as fixed-factor complementary inputs to their associated source. Abatement in each sector is modeled as a substitution between the pollutants and discrete abatement technologies, each of which is sector-specific and characterized by a marginal abatement cost and technical capacity constraint. Scenarios are run to 2020, to assess the costs and co-benefits of simultaneous air quality and climate policies. We find that under the Kyoto Protocol in 2010, the welfare cost of pollution control is reduced by 16% compared to the baseline, effectively offsetting the cost of CO2 abatement by 15%. The co-benefit results depend heavily on policy choices, and their magnitude relative to total costs is likely to decline as greenhouse targets become more ambitious. In our scenarios, pollution control cost savings range from 1.3 to 20% in 2020, yielding a climate cost offset range of 0.2 to 3.9%. The CO2 credit imports allowed by the EU via the Clean Development Mechanism (CDM) offer a total savings of $9.7bn in 2020, but only need to be compensated by an additional $0.3–0.4bn in domestic pollution control from stationary sources.

Costs and global impacts of black carbon abatement strategies

Abatement of particulate matter has traditionally been driven by health concerns rather than its role in global warming. Here we assess future abatement strategies in terms of how much they reduce the climate impact of black carbon (BC) and organic carbon (OC) from contained combustion. We develop global scenarios which take into account regional differences in climate impact, costs of abatement and ability to pay, as well as both the direct and indirect (snow-albedo) climate impact of BC and OC. To represent the climate impact, we estimate consistent region-specific values of direct and indirect global warming potential (GWP) and global temperature potential (GTP). The indirect GWP has been estimated using a physical approach and includes the effect of change in albedo from BC deposited on snow. The indirect GWP is highest in the Middle East followed by Russia, Europe and North America, while the total GWP is highest in the Middle East, Africa and South Asia. We conclude that prioritizing emission reductions in Asia represents the most cost-efficient global abatement strategy for BC because Asia is (1) responsible for a large share of total emissions, (2) has lower abatement costs compared to Europe and North America and (3) has large health cobenefits from reduced PM10 emissions.

Influence of particulate matter on the air quality situation in a mediterranean island

The objective of this study was to describe the ambient levels of particulate matter (PM) and its influence to air quality situation on the dry Mediterranean island of Cyprus. From October 2002 to August 2003 PM 10 and PM 2.5 samples were collected at 31 different sampling sites in Cyprus. In addition, continuous measurements of PM 10 were carried out from 2003 to 2007 at a traffic and a rural site. It can be recognised that at all traffic and at some residential and urban background sites, the actual EU limit values have been exceeded. Special events e.g. long-range transport of Sahara dust storms were recorded over urban as well as rural areas in the order of 6–8 events per year, with a major frequency in summer and spring periods. The comparison of the PM 10 concentrations in Cyprus cities with values of other European cities demonstrates the PM 10 problem in Cyprus, especially in the dry summer season, when no rain is cleaning the air and the dry surfaces. This underlines the necessity of PM abatement strategies.

Air Pollution Abatement: Output and Relative Price Effects, a Regional Input—Output Simulation

This paper uses the direct-cost estimates for air pollution abatement developed for an earlier study (Miernyk and Sears, 1974) to derive technical coefficients for several simulated abatement activities in West Virginia. Output and relative price effects are calculated for particulate matter abatement and two sulfur dioxide abatement alternatives, using a static input-output model.