A model for interprovincial air pollution control based on futures prices

Based on the current status of research on tradable emission rights futures, this paper introduces basic market-related assumptions for China’s interprovincial air pollution control problem. The authors construct an interprovincial air pollution control model based on futures prices: the model calculated the spot price of emission rights using a classic futures pricing formula, and determined the identities of buyers and sellers for various provinces according to a partitioning criterion, thereby revealing five trading markets. To ensure interprovincial cooperation, a rational allocation result for the benefits from this model was achieved using the Shapley value method to construct an optimal reduction program and to determine the optimal annual decisions for each province. Finally, the Beijing–Tianjin–Hebei region was used as a case study, as this region has recently experienced serious pollution. It was found that the model reduced the overall cost of reducing SO₂ pollution. Moreover, each province can lower its cost for air pollution reduction, resulting in a win–win solution. Adopting the model would therefore enhance regional cooperation and promote the control of China’s air pollution.

Implications: The authors construct an interprovincial air pollution control model based on futures prices. The Shapley value method is used to rationally allocate the cooperation benefit. Interprovincial pollution control reduces the overall reduction cost of SO₂. Each province can lower its cost for air pollution reduction by cooperation.     

Performance/Cost Estimates for Retrofitting Control Technologies

The U.S. EPA’s Air and Energy Engineering Research Laboratory is responsible for assessing control technology performance and costs under the National Acid Precipitation Assessment Program. A major part of this assessment involves developing site-specific estimates of the performance and costs of retrofitting SO₂ and NO_x control technologies for the top 200 SO₂- emitting (1980) coal-fired power plants in the 31-state eastern region. This effort includes detailed evaluation of a small number of plants (30 or less) representing a cross-section of the top 200 population. In cooperation with the states of Ohio and Kentucky (in conjunction with the U.S. EPA’s State Acid Rain Grant Program), efforts were undertaken to visit and conduct detailed evaluation of 12 coal-fired plants—five in Ohio, seven in Kentucky and the Tennessee Valley Authority System. A variety of commercial and advanced SO₂ and NO_x control technologies—including precombustion, combustion (in-furnace), and postcombustion (flue gas cleanup) technologies—were applied to each plant through conceptual designs. Retrofit factors (applied to the capital cost of a new pollution control system), cost “adders” (e.g., movement of existing equipment), and costs were developed for applying the control technologies to the boilers of each plant. Results of these and subsequent efforts will be valuable in evaluations of acid deposition control strategies by federal and state agencies and by electric utilities.     

Sulfur deposition simulations over China, Japan, and Korea: a model intercomparison study for abating sulfur emission

In response to increasing trends in sulfur deposition in Northeast Asia, three countries in the region (China, Japan, and Korea) agreed to devise abatement strategies. The concepts of critical loads and source?Creceptor (S?CR) relationships provide guidance for formulating such strategies. Based on the Long-range Transboundary Air Pollutants in Northeast Asia (LTP) project, this study analyzes sulfur deposition data in order to optimize acidic loads over the three countries. The three groups involved in this study carried out a full year (2002) of sulfur deposition modeling over the geographic region spanning the three countries, using three air quality models: MM5-CMAQ, MM5-RAQM, and RAMS-CADM, employed by Chinese, Japanese, and Korean modeling groups, respectively. Each model employed its own meteorological numerical model and model parameters. Only the emission rates for SO₂ and NO_x obtained from the LTP project were the common parameter used in the three models. Three models revealed some bias from dry to wet deposition, particularly the latter because of the bias in annual precipitation. This finding points to the need for further sensitivity tests of the wet removal rates in association with underlying cloud?Cprecipitation physics and parameterizations. Despite this bias, the annual total (dry plus wet) sulfur deposition predicted by the models were surprisingly very similar. The ensemble average annual total deposition was 7,203.6?±?370 kt S with a minimal mean fractional error (MFE) of 8.95?±?5.24?% and a pattern correlation (PC) of 0.89?C0.93 between the models. This exercise revealed that despite rather poor error scores in comparison with observations, these consistent total deposition values across the three models, based on LTP group's input data assumptions, suggest a plausible S?CR relationship that can be applied to the next task of designing cost-effective emission abatement strategies.     

Sensitivity analyses of factors influencing CMAQ performance for fine particulate nitrate

Improvement of air quality models is required so that they can be utilized to design effective control strategies for fine particulate matter (PM_2.5). The Community Multiscale Air Quality modeling system was applied to the Greater Tokyo Area of Japan in winter 2010 and summer 2011. The model results were compared with observed concentrations of PM_2.5 sulfate (SO₄^2-), nitrate (NO₃^?) and ammonium, and gaseous nitric acid (HNO₃) and ammonia (NH₃). The model approximately reproduced PM_2.5 SO₄^2? concentration, but clearly overestimated PM_2.5 NO₃^? concentration, which was attributed to overestimation of production of ammonium nitrate (NH₄NO₃). This study conducted sensitivity analyses of factors associated with the model performance for PM_2.5 NO₃^? concentration, including temperature and relative humidity, emission of nitrogen oxides, seasonal variation of NH₃ emission, HNO₃ and NH₃ dry deposition velocities, and heterogeneous reaction probability of dinitrogen pentoxide. Change in NH₃ emission directly affected NH₃ concentration, and substantially affected NH₄NO₃ concentration. Higher dry deposition velocities of HNO₃ and NH₃ led to substantial reductions of concentrations of the gaseous species and NH₄NO₃. Because uncertainties in NH₃ emission and dry deposition processes are probably large, these processes may be key factors for improvement of the model performance for PM_2.5 NO₃^?.

Implications: The Community Multiscale Air Quality modeling system clearly overestimated the concentration of fine particulate nitrate in the Greater Tokyo Area of Japan, which was attributed to overestimation of production of ammonium nitrate. Sensitivity analyses were conducted for factors associated with the model performance for nitrate. Ammonia emission and dry deposition of nitric acid and ammonia may be key factors for improvement of the model performance.     

Conjunctive Use of Models to Design Cost-Effective Ozone Control Strategies

Abstract

The management of tropospheric ozone (O₃) is particularly difficult. The formulation of emission control strategies requires considerable information including: (1) emission inventories, (2) available control technologies, (3) meteorological data for critical design episodes, and (4) computer models that simulate atmospheric transport and chemistry. The simultaneous consideration of this information during control strategy design can be exceedingly difficult for a decision-maker. Traditional management approaches do not explicitly address cost minimization. This study presents a new approach for designing air quality management strategies; a simple air quality model is used conjunctively with a complex air quality model to obtain low-cost management strategies. A simple air quality model is used to identify potentially good solutions, and two heuristic methods are used to identify cost-effective control strategies using only a small number of simple air quality model simulations. Subsequently, the resulting strategies are verified and refined using a complex air quality model. The use of this approach may greatly reduce the number of complex air quality model runs that are required. An important component of this heuristic design framework is the use of the simple air quality model as a screening and exploratory tool. To achieve similar results with the simple and complex air quality models, it may be necessary to “tweak” or calibrate the simple model. A genetic algorithm-based optimization procedure is used to automate this tweaking process. These methods are demonstrated to be computationally practical using two realistic case studies, which are based on data from a metropolitan region in the United States.     

Offsetting Stationary Source Emissions with Transportation Control Measures

Since passage of the 1977 Amendments to the Clean Air Act, comprehensive transportation planning integrating air quality attainment and maintenance with land use controls has been a major objective. Likewise, economic strategies utilizing the market potential of emission control techniques have come to the forefront as preferable control strategies. Some of these techniques include: 1) emission density zoning in which some pollution is allowed in certain areas while others are kept clean; 2) emission fees whereby cost of emission discharge would be calculated and charged to a source according to a structured market cost benefit; and 3) direct and indirect source review whereby emission increments due to additional or more effective control techniques on one source could be sold to other sources. This technique is known as offsetting emissions or as the emission offset policy.     

Do We Understand Trends in Atmospheric Sulfur Species?

ABSTRACT

Anomalies appear to exist in our understanding of atmospheric sulfur compounds, specifically as evidenced in the time trends of the different chemical forms of these compounds. Trends determined at a number of locations by several different groups seem to indicate that, responding to emission reductions across North America, the concentration of SO₂ in the atmosphere is declining more rapidly than that of aerosol SO₄ ^2-. A number of possible reasons for this discrepancy are examined, but it is not possible to provide a definitive answer at this stage. The intent is to stimulate debate, because shortcomings in our understanding of the processes involved could have profound implications for the credibility of abatement strategies and policies for both acid deposition and fine particulate matter (PM).     

Marginal abatement cost curve for nitrogen oxides incorporating controls,renewable electricity,energy efficiency,and fuel switching

A marginal abatement cost curve (MACC) traces out the relationship between the quantity of pollution abated and the marginal cost of abating each additional unit. In the context of air quality management, MACCs are typically developed by sorting control technologies by their relative cost-effectiveness. Other potentially important abatement measures such as renewable electricity, energy efficiency, and fuel switching (RE/EE/FS) are often not incorporated into MACCs, as it is difficult to quantify their costs and abatement potential. In this paper, a U.S. energy system model is used to develop a MACC for nitrogen oxides (NO_x) that incorporates both traditional controls and these additional measures. The MACC is decomposed by sector, and the relative cost-effectiveness of RE/EE/FS and traditional controls are compared. RE/EE/FS are shown to have the potential to increase emission reductions beyond what is possible when applying traditional controls alone. Furthermore, a portion of RE/EE/FS appear to be cost-competitive with traditional controls.

Implications: Renewable electricity, energy efficiency, and fuel switching can be cost-competitive with traditional air pollutant controls for abating air pollutant emissions. The application of renewable electricity, energy efficiency, and fuel switching is also shown to have the potential to increase emission reductions beyond what is possible when applying traditional controls alone.     

Optimized combinations of abatement strategies for urban mobile sources

The maximum incremental reactivity (MIR) scale was chosen as a practical index for quantifying ozone-forming impacts. The integer linear and nonlinear programming techniques were employed as the optimization method to maximize MIR and volatile organic compound (VOC) reductions, and minimize ozone's marginal cost with varied control costs. Mobile vehicles were divided into nine categories according to the demands of decision makers and the distinctive features of local circumstance in metro-Taipei. The emission factor (EF) and vehicle kilometers traveled (VKT) of each kind of vehicle were estimated by MOBILE5B model via native parameters and questionnaires. Compressed natural gas (CNG) and inspection and maintenance (I/M) were the alternative control programs for buses and touring buses; liquefied petroleum gas (LPG), I/M, methanol, electrical vehicle (EV) were for taxis and low duty gasoline vehicles. EV, methanol, and I/M were the possible control methods for two-stroke and four-stroke engine motorcycles; I/M programs for low-duty diesel trucks, heavy-duty diesel trucks, and low-duty gasoline trucks. The results include the emission ratios of specific vehicle to all vehicles, the best combination of abated measures based on different objectives, and the marginal cost for ozone and VOC with varied control costs.     

Simplified Models of U.S. Acid Rain Control Costs

Simplified algorithms are presented for estimating the cost of controlling sulfur dioxide (SO₂) emissions from existing coal-fired power plants on a state-by-state basis. Results are obtained using the detailed Utility Control Strategy Model (UCSM) to calculate the Impacts of emission reductions ranging from approximately 30 percent to 90 percent of projected 1995 emissions for 18 different scenarios and 36 states. Scenarios include the use of two dry SO₂ removal technologies (lime spray dryers and LIMB) as potential options for power plant retrofit, in addition to currently available emission control options including coal switching, coal cleaning and wet flue gas desulfurization (FGD). Technical assumptions relating to FGD system performance and the upgrading of existing cold-side electrostatic precipitators (ESP) for reduced sulfur levels are also analyzed, along with the effects of interest rates, coal prices, coal choice restrictions, plant lifetime, and plant operating levels. Results are summarized in the form of a 3-term polynomial equation for each state, giving total annualized SO₂ control cost as a function of the total SO₂ emissions reduction for each scenario. Excellent statistical fits to UCSM results are obtained for these generalized equations.     

Spatial distribution and source identification of wet deposition at remote EANET sites in Japan

Wet deposition of major ions was discussed from the viewpoint of its potential sources for six remote EANET sites in Japan (Rishiri, Happo, Oki, Ogasawara, Yusuhara, and Hedo) having sufficiently high data completeness during 2000–2004. The annual deposition for each site ranged from 12.1 to 46.6 meq m⁻² yr⁻¹ for nss-SO₄²⁻, from 5.0 to 21.9 meq m⁻² yr⁻¹ for NO₃⁻. The ranges of annual deposition of the two ions for the sites were lower than those for urban and rural sites in Japanese Acid Deposition Survey by Ministry of the Environment, Japan, and higher than those for global remote marine sites. Factor analysis was performed on log-transformed daily wet deposition of major ions for each site. The obtained two factors were interpreted as (1) acid and soil source (or acid source for some sites), and (2) sea-salt source for all the sites. This indicates that wet deposition of ions over the remote areas in Japan has a similar structure in terms of types of sources. Factor scores of acid and soil source were relatively high during Kosa (Asian dust) events in spring in western Japan. Back-trajectories for high-deposition episodes of acid and soil source (or acid source) for the remote sites showed that episodic air masses frequently came from the northeastern area of Asian Continent in spring and winter, and from central China in summer and autumn. This indicates a large contribution of continental emissions to wet deposition of ions over the remote areas in Japan.     

Reducing Air Pollutant Emissions at Airports by Controlling Aircraft Ground Operations

Potential reductions in air pollutant emissions were determined for four strategies to control aircraft ground operations at two case study airports, Los Angeles and San Francisco International Airports. Safety, cost, and fuel savings associated with strategy implementation were examined.

Two strategies, aircraft towing and shutdown of one engine during taxi operations, provided significant emission reductions. However, there are a number of safety problems associated with aircraft towing. The shutdown of one engine while taxiing was found to be the most viable strategy because of substantial emission reductions, cost benefits resulting from fuel savings, and no apparent safety problems.     

Acidic and alkaline precipitation components in the mesoscale range under the aspect of meteorological factors and the emissions

At two sites in the north of the G.D.R. 80–100 km distant from industry rain from individual precipitation events was collected by automatic samplers and relevant ionic species were analyzed. The sampler is described.The cloud routes at the 850 hPa level were traced back 1 day and then seven sectors were formed for each collection site taking into consideration geographical aspects and features of the emission pattern for the rea concerned.Investigating the precipitation components as a function of the emission pattern knowledge of meteorological input parameters are required. The influence of these parameters is reported.Contrary to the combustion of other fossil fuels, in the case of brown coal combustion a considerable emission of neutralizing components (especially CaO) occurs, counteracting the formation of “acid rain”. This effect is clearly proven by means of individual examples and average considerations, i.e. the formation of acid rain does not only depend on the SO₂ and NO_x emissions.The wet deposition of all types of ions at the measuring site for every emission sector was calculated by means of precipitation statistics. Using these investigations reference points with regard to border crossing transport are given.     

Formaldehyde Concentrations Inside Private Residences: A Mail-Out Approach to Indoor Air Monitoring

Abstract

The main objective of this study was to monitor the volatile organic compounds (VOCs) in the stack gas released from organic chemical industrial plants to determine emission factors. Samples from 52 stacks, with or without air pollution control devices (APCDs), from seven industrial processes were taken and VOCs measured using U.S. Environmental Protection Agency (EPA) Method 18. These 7 processes, including 26 plants, were the manufacturers of acrylonitrile–butadiene–styrene (ABS), polyvinyl chloride (PVC), polystyrene (PS), acrylic resin (ACR), vinyl chloride (VC), para–terephthalic acid (PTA), and synthetic fiber (SYF). The results clearly indicate significant variations of emission factors among the various industrial processes, particularly emission factors for those without APCDs. As expected, those with APCDs yield much less emission factors. Regardless of those with or without APCDs, the order of manufacturing processes with regard to VOC emission factors is SYF > ABS > PS > ACR > PTA > PVC > VC. The emission factors for some processes also differ from those in EPA–42 data file. The VOC profiles further indicate that some VOCs are not listed in the U.S. VOC/Particulate Matter Speciation Data System (SPECIATE). The potential O₃ formation is determined from the total amount of VOC emitted for each of seven processes. The resultant O₃ yield varied from 0.22 (ACR) to 2.33 g O₃ g^–1 VOC (PTA). The significance of this O₃ yield is discussed.     

The Cost of Stack Gas Cleaning in New York State

A cost estimating methodology has been applied to an emission point inventory to estimate the capital and operating costs of stack gas cleaning in the manufacturing sector of New York State. The study represents the first major attempt to estimate control costs on a source by source basis for a large region. The various control cost components are presented for each of the twenty manufacturing industry groups and the usefulness of the estimates for an abatement planning model is outlined.

In recent years a number of heroic efforts have been made to estimate the cost of air pollution abatement on a national or regional basis. Unfortunately, these studies have relied almost entirely upon emission factors, cost engineering functions, pilot plant operations, and average or ideal firms, because of the paucity of primary data.^1-6

In the estimates of capital and operating costs presented below, an attempt has been made to improve on previous research by making extensive use of primary data. The data were taken from an emission inventory of over 20,000 sources of air contamination in New York State. A cost estimating methodology was applied to engineering parameters of existing control operations on a source by source basis. The results have been aggregated to the two-digit SIC level.     

Short-term effect of increasing nitrogen deposition on CO2, CH4 and N2O fluxes in an alpine meadow on the Qinghai-Tibetan Plateau,China

An increasing nitrogen deposition experiment (2 g N m^?2 year^?1) was initiated in an alpine meadow on the Qinghai-Tibetan Plateau in May 2007. The greenhouse gases (GHGs), including CO₂, CH₄ and N₂O, was observed in the growing season (from May to September) of 2008 using static chamber and gas chromatography techniques. The CO₂ emission and CH₄ uptake rate showed a seasonal fluctuation, reaching the maximum in the middle of July. We found soil temperature and water-filled pore space (WFPS) were the dominant factors that controlled seasonal variation of CO₂ and CH₄ respectively and lacks of correlation between N₂O fluxes and environmental variables. The temperature sensitivity (Q₁₀) of CO₂ emission and CH₄ uptake were relatively higher (3.79 for CO₂, 3.29 for CH₄) than that of warmer region ecosystems, indicating the increase of temperature in the future will exert great impacts on CO₂ emission and CH₄ uptake in the alpine meadow. In the entire growing season, nitrogen deposition tended to increase N₂O emission, to reduce CH₄ uptake and to decrease CO₂ emission, and the differences caused by nitrogen deposition were all not significant (p < 0.05). However, we still found significant difference (p < 0.05) between the control and nitrogen deposition treatment at some observation dates for CH₄ rather than for CO₂ and N₂O, implying CH₄ is most susceptible in response to increased nitrogen availability among the three greenhouse gases. In addition, we found short-term nitrogen deposition treatment had very limited impacts on net global warming potential (GWP) of the three GHGs together in term of CO₂-equivalents. Overall, the research suggests that longer study periods are needed to verify the cumulative effects of increasing nitrogen deposition on GHG fluxes in the alpine meadow.     

Inorganic Acid Emission Factors of Semiconductor Manufacturing Processes

Abstract

A huge amount of inorganic acids can be produced and emitted with waste gases from integrated circuit manufacturing processes such as cleaning and etching. Emission of inorganic acids from selected semiconductor factories was measured in this study. The sampling of the inorganic acids was based on the porous metal denuders, and samples were then analyzed by ion chromatography. The amount of chemical usage was adopted from the data that were reported to the Environmental Protection Bureau in Hsin-chu County according to the Taiwan Environmental Protection Agency regulation. The emission factor is defined as the emission rate (kg/month) divided by the amount of chemical usage (L/month). Emission factors of three inorganic acids (i.e., hydrofluoric acid [HF], hydrochloric acid [HQ], and sulfuric acid [H₂SO₄]) were estimated by the same method. The emission factors of HF and HCl were determined to be 0.0075 kg/L (coefficient of variation [CV] = 60.7%, n = 80) and 0.0096 kg/L (CV = 68.2%, n = 91), respectively. Linear regression equations are proposed to fit the data with correlation coefficient square (R²) = 0.82 and 0.9, respectively. The emission factor of H₂SO₄, which is in the droplet form, was determined to be 0.0016 kg/L (CV = 99.2%, n = 107), and its R² was 0.84. The emission profiles of gaseous inorganic acids show that HF is the dominant chemical in most of the fabricators.     

Environmental chamber test methodology for characterizing organic vapors from solid emission sources

Environmental test chambers are an important tool in the characterization of organic emissions from solid consumer and construction products and in the evaluation of their potential impact on indoor air quality. The results of extensive research concerning formaldehyde (CH₂O) emissions from such products strongly support this application of environmental chambers to measure product emissions and provide useful input for the design of environmental chamber studies. The physical design and test methodology for environmental chambers are strongly influenced by several elements in a comprehensive project plan for source characterization, including the selection process for test samples and the mathematical models used to interpret the organic emissions data. The protocol for environmental chamber testing extends broadly from the acquisition, preparation and conditioning of test specimens, to the selection and control of environmental test conditions, and to the calibration and measurement of system parameters and organic emissions. The requirements for environmental control inside the test chamber can be estimated from the sensitivity of the organic emission rates of the test products (e.g. CH₂O emissions from pressed-wood products) to variation in environmental parameters. The cost of the numerous, multiple-organic analyses required for environmental chamber testing of solid emitters is seen as a strong limitation to product selection strategies and modeling efforts. The modeling of organic emissions from solid emitters can be both a planning tool for development of chamber test methodology and a means to interpret test chamber results.     

Assessing the impact of the acid deposition control program

A goal of the acidic deposition control program in the United States has been to link emissions control policies, such as those mandated under Title IV of the US Clean Air Act Amendments (CAAA) of 1990, to improvements in air and water quality. Recently, several researchers have reported trends in the time series of pollutant data in an effort to evaluate the effectiveness of the CAAA in reducing the acidic deposition problem. It is well known that pollutant concentrations are highly influenced by meteorological and climatic variations. Also, spatial and temporal inhomogeneities in time series of pollutant concentrations, induced by differences in the data collection, reduction, and reporting practices, can significantly affect the trend estimates. We present a method to discern breaks or discontinuities in the time series of pollutants stemming from emission reductions in the presence of meteorological and climatological variability. Using data from a few sites, this paper illustrates that linear trend estimates of concentrations of SO₂, aerosol SO₄²⁻, and precipitation-weighted SO₄²⁻ and NO₃⁻ can be biased because of such complex features embedded in pollutant time series.