Coal-fired Power Plant Emissions Research Articles

Assessment and offset of the adverse effects induced by PM2.5 from coal-fired power plants in China

Coal-fired power plants are major sources of air pollution in China. Primary particulate matter, sulfur dioxide (SO2) and nitrogen oxides (NOX) emitted from coal-fired power plants formed a large amount of PM2.5 and further imposed heavy burdens on human health and socio-economy. Thus, there is a growing need to assess such adverse effects and explore effective approaches to offset them. This study aims to advance an integral framework, covering health impact assessment, economic loss estimation and adverse effects offset, to understand and mitigate the negative effects induced by PM2.5 from coal-fired power plants in China. In detail, an emission-based model recommended by United Nations Environment Program (UNEP) was adopted to link the emissions of coal-fired power plants with premature mortality cases (PMC). Then, the economic losses triggered by PMC (including the integral loss, the macro loss and the direct loss) were assessed from multiple perspectives. After that, two approaches, respectively aiming to identify the key coal-fired power plants and optimize the economic structure, were developed to offset the economic losses. We found that 22,231 premature mortality cases occurred in China during 2012 due to PM2.5 from coal-fired power plants (accounting for 0.02‰ of the national population). The corresponding integral loss amounted to CNY 17 billion and was equivalent with 0.03‰ of China’s GDP in 2012. Emission abatement against key coal-fired power plants had potential to decrease the integral loss by 23.18%. Increasing the self-input coefficient of the chemical industry in Shandong by 0.018% could offset the integral loss. At provincial level, Jiangsu payed the greatest cost in health and economy, and played the vital role in cross-provincial loss. The PMC occurred in Liaoning entailed great economic losses of other provinces, while the total output of Beijing was sensitive to the PMC occurred in other provinces. These results could provide new insights for the rational policy development to ensure the long-term social welfare.

Ash formation and trace elements associations with fine particles in an ultra-low emission coal-fired power plant

To meet the strict environmental requirements, air pollutions control devices are commonly installed in coal-fired power plants in China. Better understanding of porperties of particulate matters and trace elemetns associations are important for comprehensive evaluations on environmental impacts caused by the ultra-low emiission retrofits. This work have analyzed ash formaion and trace elements emissions as well as their associations with particulate matters in an ultra-low emission coal-fired power plant. The results indicate that ultra-low emission retrofits would greatly reduce particulate matters emissions, and trace elements distributions in bottom ash, fly ash, and fine particles are not significant changed. However, it would affect trace elements distributions in particulate matter from different sampling sites, which is due to the alternations on ash fromation caused by the change of local reaction conditions, thus affecting the particualte matter properties and trace elements migration behaviors. Electrostatic precipitator and wet electrostatic precipitator are capable for most of trace elements laden particle matter removal, but the particulate matters escaped from wet electrostatic precipitator are enriched in As, Cu, Zn, and Pb. Particle size would affect those 4 kinds of trace elements distributions in fly ashes. As and Pb would accumulate in particles with size decreasing in the fractions from 10 μm to 0.5 μm. While Cu and Zn enrich in particles in size fractions of 1 μm. The associations of As, Cu, and Pb with other species in a single particle are also presented, which would be helpful for understanding the trace elements migration and accumulation behaviors in particulate matter.

Health improvements associated with reduced power plant emissions in the United States between 2005 and 2012

Background. Emissions from coal power plants have fallen dramatically since the passage of the 1990 Clean Air Act Amendments. We quantify and compare changes in 10 health outcomes among US Medicare beneficiaries attributable to two different—but related—metrics over this time period: total PM2.5 and exposure to pollution derived from coal-fired power plant emissions.Methods. We use a new approach—the HYSPLIT average dispersion model, or HyADS—to quantify changes in ZIP code level exposure to SO2 emissions from each of 1,036 U.S. coal power plants between 2005 and 2012. We conduct an analogous analysis using ZIP code level PM2.5 ambient exposure. We use a first differences regression approach to compare how the change in health outcome rates from 2005 to 2012 is associated with changes in PM2.5 and coal exposure during the same period.Results. Most ZIP codes saw reductions in PM2.5 and coal exposure across the study period. Decreases in the rates of five health outcomes between 2005 and 2012—all cardiovascular disease, cardiovascular stroke, heart failure, ischemic heart disease, and respiratory tract infection—show statistically significant associations with both reduced PM2.5 concentrations and reduced coal exposure. Decreases in rates of heart rhythm disorders, peripheral vascular disease, and all-cause mortality do not show relationships with changes in either exposure. Coal exposure reductions are associated with decreases in rates of chronic obstructive pulmonary disorder, whereas reductions in PM2.5 exposure are not.Conclusions. Results show consistent relationships between coal power plant emission reductions from 2005 to 2012 and decreases in multiple Medicare health outcomes. Further, differences are apparent between health impacts of changing exposure to PM2.5 and coal-fired power plant emissions. The approach provides more direct evidence of the benefits of regulations on coal power plants than previous approaches that employ relationships between observed air quality and health.

A Potential Approach to Compensate the Gas Interference for the Analysis of NO by a Non-dispersive Infrared Technique.

Interference is a pivotal issue of a non-dispersive infrared (NDIR) sensor and analyzer. Therefore, the main contribution of this study is to introduce a potential method to compensate for the interference of the NDIR analysis. A potential method to compensate for the interference of a nitric oxide (NO) NDIR analyzer was developed. Double bandpass filters (BPFs) with HITRAN (high-resolution transmission molecular absorption database)-based wavelengths were used to create an ultranarrow bandwidth, where there were least-interfering effects with respect to the coal-fired power plant emission gas compositions. Key emission gases from a coal-fired power plant, comprising carbon monoxide (CO), NO, sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon dioxide (CO2), and water (H2O) (in the form of vapor), were used to investigate the gas interference. The mixtures of those gases were also used to investigate the performance of the double BPFs. We found that CO, CO2, SO2, and H2O significantly affected the detection of NO when a commercial, single narrow BPF was used. In contrast, the double BPFs could remove the interference of CO, NO2, SO2, and CO2 in terms of their concentrations. In the case of H2O, the filter performed well until a level of 50% relative humidity at 25 °C. Moreover, the signal-to-noise ratio of the analyzer was approximately 10 when the double BPFs were applied. In addition, the limit of detection of the analyzer with the double BPFs was approximately 4 ppm, whereas that with the commercial one was 1.3 ppm. Therefore, double BPFs could be used for an NO NDIR analyzer instead of a gas filter correlation to improve the selectivity of the analyzer under the condition of a known gas composition, such as a coal-fired power plant. However, the sensitivity of the analyzer would be decreased.

Metal contamination and bioremediation of agricultural soils for food safety and sustainability

Agricultural soil is a non-renewable natural resource that requires careful stewardship in order to achieve the United Nations’ Sustainable Development Goals. However, industrial and agricultural activity is often detrimental to soil health and can distribute heavy metal(loid)s into the soil environment, with harmful effects on human and ecosystem health. In this Review, we examine processes that can lead to the contamination of agricultural land with heavy metal(loid)s, which range from mine tailings runoff entering local irrigation channels to the atmospheric deposition of incinerator and coal-fired power-plant emissions. We discuss the relationship between heavy metal(loid) biogeochemical transformations in the soil and their bioavailability. We then review two biological solutions for remediation of contaminated agricultural land, plant-based remediation and microbial bioremediation, which offer cost-effective and sustainable alternatives to traditional physical or chemical remediation technologies. Finally, we discuss how integrating these innovative technologies with profitable and sustainable land use could lead to green and sustainable remediation strategies, and conclude by identifying research challenges and future directions for the biological remediation of agricultural soils. Contamination of agricultural soils by heavy metals and metalloids has severe consequences on human and ecosystem health. This Review discusses the sources of heavy metal(loid) contamination, the mechanisms by which these contaminants interact with biological and geochemical soil elements, and plant-based and microorganism-based remediation strategies.

Characteristics of condensable particulate matter before and after wet flue gas desulfurization and wet electrostatic precipitator from ultra-low emission coal-fired power plants in China

Total particulate matters emitted from coal-fired power plants generally include condensable particulate matter (CPM) and filterable particulate matter (FPM). Based on the on-site sampling of CPM, this study investigated four typical coal-fired power plants equipped with ultra-low emission facilities in north China. In order to clarify the characteristics of CPM before and after wet flue gas desulfurization (WFGD) and wet electrostatic precipitator (WESP), the mass concentrations, organic and inorganic compositions of the CPM were analyzed. Among the four test power plants, the emission concentrations of CPM were 2.20–7.33 mg/Nm3, accounting for 57.74–91.79% of PM2.5. The organic component accounted for 59.64% of the total mass concentration of CPM on average. Alkanes, esters and amides were the major organic components. And the water-soluble ions contributed significantly to the inorganic component of CPM. The proportion of SO42− was the highest, followed by Cl− and NO3−. In addition, this study found that the concentration of SO42− increased significantly while SO3 decreased from WESP inlet to outlet. It was indicated that ultrafine particles and soluble SO2 in flue gas could contribute to the formation of SO42− in CPM besides SO3. As an important part of CPM, further studies should be conducted on the factors affecting SO42−.

Posterior predictive treatment assignment methods for causal inference in the context of time-varying treatments

Abstract Marginal structural models (MSM) with inverse probability weighting (IPW) are used to estimate causal effects of time-varying treatments, but can result in erratic finite-sample performance when there is low overlap in covariate distributions across different treatment patterns. Modifications to IPW which target the average treatment effect (ATE) estimand either introduce bias or rely on unverifiable parametric assumptions and extrapolation. This paper extends an alternate estimand, the ATE on the overlap population (ATO) which is estimated on a sub-population with a reasonable probability of receiving alternate treatment patterns in time-varying treatment settings. To estimate the ATO within an MSM framework, this paper extends a stochastic pruning method based on the posterior predictive treatment assignment (PPTA) (Zigler, C. M., and M. Cefalu. 2017. “Posterior Predictive Treatment Assignment for Estimating Causal Effects with Limited Overlap.” eprint arXiv:1710.08749.) as well as a weighting analog (Li, F., K. L. Morgan, and A. M. Zaslavsky. 2018. “Balancing Covariates via Propensity Score Weighting.” Journal of the American Statistical Association 113: 390–400, https://doi.org/10.1080/01621459.2016.1260466.) to the time-varying treatment setting. Simulations demonstrate the performance of these extensions compared against IPW and stabilized weighting with regard to bias, efficiency, and coverage. Finally, an analysis using these methods is performed on Medicare beneficiaries residing across 18,480 ZIP codes in the U.S. to evaluate the effect of coal-fired power plant emissions exposure on ischemic heart disease (IHD) hospitalization, accounting for seasonal patterns that lead to change in treatment over time.

Fine Particulate Emission Characteristics of an Ultra-Low Emission Coal-Fired Power Plant

Since the introduction of ultra-low emissions, the characteristics of particulate matter (PM) emissions from coal-fired power plants have changed. We quantitatively evaluate the emission characteristics of each component in PM and the impact of purification equipment by analyzing three ultra-low emission units of coal-fired power plants (FP1, FP2, and FP3). A DGI was used to sample particles from the wet flue gas desulfurization (WFGD) unit and wet electrostatic precipitator (WESP) inlet and outlet, which were then analyzed by various methods. The results showed that the mass concentrations of PM1, PM2.5, and PM10 discharged from the outlets of the three units were 0.25-0.38, 0.31-0.42, and 0.42-0.57 mg·m-3, respectively, and that the mass concentration of PM10 discharged under the two kinds of units was equivalent. However, there were differences in the particle size distribution and composition of the particles. In comparison to the FP1 and FP2 units, the PM2.5/PM10 ratio of the FP3 unit was the highest. A possible reason for this is that the unit was equipped with a WESP, which can better remove particle sizes of 2.5 μm or more. The total concentrations of water-soluble ions in PM2.5 discharged from the FP2 and FP3 units were 0.20 and 0.06 mg·m-3, respectively. The water-soluble ions emitted from the FP2 unit were mainly Ca2+ and SO42-, whereas those mainly emitted from the FP3 unit were NH4+ and SO42-. Analysis of the PM from the WFGD import and export of the FP2 unit showed that the WFGD process increased the water-soluble ion discharge by entraining the desulfurization slurry containing limestone and gypsum. Addition of a WESP after WFGD can effectively remove PM2.5 and PM10 particles and reduce the influence of water-soluble ions on the atmospheric environment.

CO2 Emission Calculation and Emission Characteristics Analysis of Typical 600MW Coal-fired Thermal Power Unit

In order to effectively reduce the total CO2 emissions of coal-fired power plants and reduce greenhouse gas emissions, the relevant data of a typical 600MW coal-fired power plant in the past five years was collected and investigated, and CO2 emissions and emission intensity were calculated. And the results were used to measure the CO2 emission level of coal-fired power plants. By comparing and analyzing the CO2 emission intensity and emission trend of 600MW coal-fired units with different unit types and different fuel types, the CO2 emission characteristics of typical 600MW coal-fired power plants are obtained.

Techno-economic analysis of ultra-supercritical power plants using air- and oxy-combustion circulating fluidized bed with and without CO2 capture

The adoption of oxy-combustion in a circulating fluidized bed (CFB) producing ultra-supercritical (USC) steam has been investigated to increase energy efficiency and reduce CO2 emissions of coal-fired power plants. This paper presents a techno-economic analysis for 500 MWe USC-CFB power plants with air- and oxy-combustion in the presence of CO2 capture. An amine absorber unit (AAU) and a CO2 processing unit (CPU) were used to capture CO2 in the air- and oxy-combustion power plants, respectively. The air-combustion power plant without CO2 capture (Case 1) showed the highest net electricity efficiency (46%), whereas the introduction of an AAU in the air-combustion power plant (Case 2) reduced the net efficiency to 36%. The net efficiency (39%) of the oxy-combustion power plant with CPU (Case 3) was higher than that of Case 2 owing to the recycling of hot flue gas. The levelized cost of electricity (LCOE) of Case 3 (59 $/MWh) was lower than that of Case 2 (64 $/MWh), which demonstrated that oxy-combustion was advantageous compared to air-combustion in a scenario with CO2 capture. The sensitivity analyses of the electricity price and CO2 credit showed economic situations where Cases 2 and 3 would be profitable.

Variation characteristics of final size-segregated PM emissions from ultralow emission coal-fired power plants in China

The ultralow emission (ULE) retrofits for Chinese coal-fired power plants (CFPPs) are nearing completion. Large-scale and rapid retrofits have resulted in significant changes in the emission level and characteristics of particulate matter (PM). To investigate the variation characteristics of final three size fractions PM (PM2.5, PM10−2.5, PM>10) emissions, we conducted field tests at the outlets of wet flue gas desulfurization (WFGD) and wet electrostatic precipitator (WESP) by a pair of two-stage virtual impactors in eight representative ULE CFPPs. Our results indicate that, after WESP installations, the mass concentrations of final PM are significantly reduced and those of the final total ions and elements decrease as most individual chemical compositions are reduced. WESP presents an excellent removal performance for large particle sizes and high PM concentrations. SO42− is the major ionic component at both the outlets of WFGD and WESP, and its proportion in total ions is reduced to some extent through WESP. Furthermore, the average mass contents of SO42− and most elements in PM2.5 are significantly lower than those in PM10−2.5 and PM>10 whether at the WFGD-outlets or WESP-outlets. By comparison, chemical profiles of PM have substantially changed after ULE retrofits, and those after WFGD (e.g., sulfate, Zn, Pb, and Cu) have also changed relative to existing data. The end-tail emission factors (EFs) of PM2.5, PM10, and PMtotal under the typical ULE technical routes of WESP are calculated in time, and the corresponding EFs are in the range of 2.82–8.97, 15.7–27.6, and 38.6–61.7 g t−1, respectively. We believe the latest detailed PM EFs and the associated chemical profiles provided in this study are more representative of the current emission situations of Chinese CFPPs.

Field test of SO3 removal in ultra-low emission coal-fired power plants.

Under the extensive implementation of ultra-low emission (ULE) facilities in coal-fired power plants of China, sulfur trioxide (SO3) has received increasing attention due to its impact on human health and operation safety of power plants. However, systematic research and evaluation for controlling SO3 emission in various ULE facilities are still lacking. Here, a systematic study was conducted based on 378 in situ performance evaluation tests carried out in 148 coal-fired power plants. The results illustrate that the SO2/SO3 conversion rate of the selective catalytic reduction devices can be controlled within 1% before and after ULE retrofit. Also, the synergistic removal efficiency of SO3 in the low-low-temperature electrostatic precipitator and the wet electrostatic precipitator can be higher than 70%. The removal efficiency of SO3 in the wet limestone-gypsum flue gas desulfurization scrubber is 33-64% before ULE and 31-81% after, and the average efficiency of the double scrubbers is 8.7% higher than that of the single scrubber. Due to the different SO3 removing abilities of various technologies, the overall efficiency of SO3 removal is in the range between 27 and 95% adopting different ULE technical routes. Average concentration of SO3 emission can be decreased by 51.8% after ULE application.

Migration and distribution characteristics of organic and inorganic fractions in condensable particulate matter emitted from an ultralow emission coal-fired power plant.

Condensable particulate matter (CPM) is the main part of total particulate matter (TPM) discharged from coal-fired power plants. In this study, a new analytical method was proposed for accurately quantifying the organic components including n-alkanes and phthalates in CPM that sampled from an ultralow emission coal-fired plant by using the Gas Chromatography-Mass Spectrometer (GC-MS) and the mixed standard solution. The organic fraction made up 53.13%, 50.90%, 52.44% of the CPM tested at the outlet of the low-low temperature electrostatic precipitator (LLT-ESP), the wet flue gas desulfurization (WFGD) and the wet electrostatic precipitator (WESP), respectively. The total concentration of 19 kinds of n-alkanes range from 0.328 mg/Nm3 to 0.854mg/Nm3 with C24-C30 becoming the major n-alkanes compounds in all sampling sites. The chief component of the tested phthalate was the di-n-butyl ortho-phthalate (DBP) which comprised 95.43%, 88.29%, 95.33% of the total of five kinds of phthalates. The WFGD contributed to the reduction of phthalates and the generation of n-alkanes while the effects on WESP were opposite. Furthermore, the existing air pollution control devices (APCDs) had no significant selection for the removal of n-alkanes causing the proportions of different n-alkanes were almost the same in different sampling sites. Also, the mechanism of the APCDs on the removal of CPM organic fraction was proposed primarily. The proportion of organic components measured in the organic fractions was less than 15%. Accurate quantification of other organic compounds and the mechanism of pollutant removal should be studied in the future.

МЕЗОМАСШТАБНЫЕ ПРОЦЕССЫ ПЕРЕНОСА АТМОСФЕРНЫХ ЗАГРЯЗНЕНИЙ В РАЙОНЕ ЮЖНОГО БАЙКАЛА

The article considers the results of experimental studies of mesoscale processes of atmospheric pollution transfer to the southern Baikal in the system of low-level atmospheric jet flows in the atmospheric boundary layer at heights up to 100–600 m. It is shown that the plumes of atmospheric emissions of large coal-fired power plants can be captured by the atmospheric jets and transferred to hundreds of kilometers without significant scattering and deposition. Such cases are observed, as a rule, at night and more often in the cold season of the year. The main pollutants in these plumes are sulfur dioxide and nitrous oxides, concentration of which in the region of Lake Baikal (70 km from the source) can reach the level from hundreds to thousands µg/m3. In the process of transfer, nitrogen oxides are partially oxidized by atmospheric ozone to nitrates (mainly to nitric acid), while ozone concentrations in the plume zone drop to zero, completely expending on oxidation.

Near-zero emission coal-fired power plant using advanced KM CDR process™

CCS is expected to be one of the major measures contributing to carbon reduction and meet net zero emission in near future. Fossil fuel power plants equipped with CCS can be considered to be zero-carbon power generation if nearly full CO2 recovery is feasible. The objective of this paper is to investigate the process performance and plant economics at 99.5% CO2 capture ratio that has not been studied before using MHIENG’s CO2 capture technology. It is expected that this work using experiences and empirical data that MHIENG has accumulated is more indicative of current commercial CCS technology and economics than previous work. The near-zero emission design proposed in this work using 50% additional absorption packing achieves 99.5% capture ratio with similar normalized OPEX ($/tonne CO2) and 6% higher normalized CAPEX compared to base case at 90% capture ratio. Near-zero emission coal-fired power plant is technically feasible using the Advanced KM CDR Process™ and KS-1™ solvent and will increase cost of CO2 captured by 3% compared to default design at 90% capture ratio.

A multi-level analysis of the impact of changes in coal-fired power plant emissions on asthma-related healthcare utilization and symptoms in Louisville, Kentucky

A multi-level analysis of the impact of changes in coal-fired power plant emissions on asthma-related healthcare utilization and symptoms in Louisville, Kentucky

What Are the Benefits of Re-Adjusting the National Ambient Air Quality Standards?

The Clean Air Act's National Ambient Air Quality Standards (NAAQS) set limits on ambient air concentrations of hazardous pollutants. Since its creation, NAAQS guidelines have evolved to curb ambient concentrations of Particulate Matter less than 2.5 ug in diameter (PM2.5), which have been linked to respiratory and heart problems. However, the last adjustment to all (annual mean and 24-hour) PM2.5 standards occurred in 1997. This study evaluates the health benefits of tighter standards via reduced coal-fired power plant emissions of sulfur dioxide (SO2) and nitrous oxide (NOx), primary precursors to ambient PM2.5 concentrations. We find that reducing current annual and 24-hour PM2.5 standards would result in nationwide health benefits of at least $970 million in the year following enactment. We further find that the proposed standards are net benefit positive when incorporating abatement costs.

Mercury and methylmercury levels in soils associated with coal-fired power plants in central-northern Chile

Mercury pollution is a worldwide problem, and is associated with a number of natural and anthropogenic processes. The present work, conducted in Chile, a country that has traditionally depended heavily on fossil fuels for power generation, examines total mercury (THg) and monomethylmercury (MMHg) concentrations in soils across different sites exposed to coal fired power plant emissions. Samples from four selected (Renca, Laguna Verde, Las Ventanas, Huasco) and 1 control (Quintay) sites were analyzed using cold vapour and fluorescence spectroscopy (CV-AFS) for THg determination and chromatographic separation with atomic fluorescence detection (DI-GC-AFS) was followed for speciation analysis.From the sites analyzed, Renca and Las Ventanas showed high concentrations of total mercury, exhibiting ranges between 135 – 568 and 94–464 ng g−1 respectively, while Laguna Verde and Huasco exhibited lower values ranged 5–27 and 9–44 ng g−1 respectively. Conversely, analysis of MMHg concentrations showed that only Renca site possessed high values, ranging between 0.1 and 3.0 ng g−1, resulting in this site being considered contaminated. Conversely, other sites showed minimal values comparable to the control site (0.024 ± 0.003 ng g−1) in terms of MMHg concentrations. An analysis of the differences between MMHg and THg concentrations in contaminated sites, suggests an overall absence of methylation in soils of Las Ventanas, probably related to the very high levels of soil heavy metals, especially copper. Moreover, the influence of the composition and physicochemical properties of the different soils on the mobility of the species was assessed. Results obtained (as Log Kd) were 3.5 and 4.1 for Renca and Las Ventanas respectively, suggesting low mobility of mercury species in the environment for both sites.Finally, the data obtained allowed us to establish a first approximation of the differences in concentration and mobility of total and MMHg associated with coal fired power plants emission in central-northern Chile, an area previously understudied in a country heavily dependent on fossil-fuels.

Evaluation of co-firing as a cost-effective short-term sustainable CO2 mitigation strategy in Germany

BackgroundIn order to achieve the German greenhouse gas reduction targets, in particular, CO2 emissions of coal-fired power plants must be reduced. The co-incineration of biomass-based substitutes, here referred to as co-firing, is regarded as a highly cost-effective and short-term method of reducing CO2 emissions in the electricity sector. Another advantage of co-firing is its ability to meet base load demands and offer controllability. In this paper, we, therefore, evaluate the effectiveness of co-firing as a CO2 mitigation strategy in the German electricity sector by 2020.MethodsWe consider the co-firing of three different substitutes: wood chips, industry pellets and torrefied biomass. Likewise, a comparison with three alternative mitigation strategies is part of the evaluation. We use seven sustainability indicators covering social, ecological and economic aspects as the basis for the evaluation. These sustainability indicators are determined by means of a merit order model, which enables us to simulate the electricity market in 2020 on an hourly basis and adjust it based on the assumption of widespread implementation of co-firing or one of the alternative mitigation strategies.ResultsOur results show that all mitigation strategies have a significant potential to reduce the CO2 emissions of the electricity sector. Compared with the alternative mitigation strategies, co-firing is characterised on the one hand by rather low mitigation potentials and on the other hand by low CO2 mitigation costs. The co-firing of industry pellets appears to have the most advantageous combination of mitigation potential and mitigation costs.ConclusionsThe widespread implementation of co-firing with industry pellets until 2020 would have led to 21% reduction in CO2 emissions on average. Nevertheless, it cannot be implemented immediately because time is needed for political decisions to be taken and, afterwards, for the technical retrofitting of power plants. Co-firing will, therefore, not be available to contribute to the achievement of the greenhouse gas reduction targets for the year 2020. However, our approach can be used to assess the contribution of the various CO2 mitigation strategies to the ambitious mitigation targets for the year 2030.

Accountability Assessment of Health Improvements in the United States Associated with Reduced Coal Emissions Between 2005 and 2012.

National, state, and local policies contributed to a 65% reduction in sulfur dioxide emissions from coal-fired power plants between 2005 and 2012 in the United States, providing an opportunity to directly quantify public health benefits attributable to these reductions under an air pollution accountability framework. We estimate ZIP code-level changes in two different-but related-exposure metrics: total PM2.5 concentrations and exposure to coal-fired power plant emissions. We associate changes in 10 health outcome rates among approximately 30 million US Medicare beneficiaries with exposure changes between 2005 and 2012 using two difference-in-difference regression approaches designed to mitigate observed and unobserved confounding. Rates per 10,000 person-years of six cardiac and respiratory health outcomes-all cardiovascular disease, chronic obstructive pulmonary disorder, cardiovascular stroke, heart failure, ischemic heart disease, and respiratory tract infections-decreased by between 7.89 and 1.95 per (Equation is included in full-text article.)decrease in PM2.5, with comparable decreases in coal exposure leading to slightly larger rate decreases. Results for acute myocardial infarction, heart rhythm disorders, and peripheral vascular disease were near zero and/or mixed between the various exposure metrics and analyses. A secondary analysis found that nonlinearities in relationships between changing health outcome rates and coal exposure may explain differences in their associations. The direct analyses of emissions reductions estimate substantial health benefits via coal power plant emission and PM2.5 concentration reductions. Differing responses associated with changes in the two exposure metrics underscore the importance of isolating source-specific impacts from those due to total PM2.5 exposure.