scholarly journals The effect of coal-fired power-plant SO<sub>2</sub> and NO<sub>x</sub> control technologies on aerosol nucleation in the source plumes

2012 ◽  
Vol 12 (23) ◽  
pp. 11519-11531 ◽  
Author(s):  
C. R. Lonsdale ◽  
R. G. Stevens ◽  
C. A. Brock ◽  
P. A. Makar ◽  
E. M. Knipping ◽  
...  
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Particle Formation ◽  
Particle Nucleation ◽  
Nox Emissions ◽  
Emissions Control ◽  
So2 Emissions ◽  
The Us ◽  
Order Of Magnitude ◽  
Control Technologies

Abstract. Nucleation in coal-fired power-plant plumes can greatly contribute to particle number concentrations near source regions. The changing emissions rates of SO2 and NOx due to pollution-control technologies over recent decades may have had a significant effect on aerosol formation and growth in the plumes with ultimate implications for climate and human health. We use the System for Atmospheric Modeling (SAM) large-eddy simulation model with the TwO-Moment Aerosol Sectional (TOMAS) microphysics algorithm to model the nucleation in plumes of coal-fired plants. We test a range of cases with varying emissions to simulate the implementation of emissions-control technologies between 1997 and 2010. We start by simulating the W. A. Parish power plant (near Houston, TX) during this time period, when NOx emissions were reduced by ~90% and SO2 emissions decreased by ~30%. Increases in plume OH (due to the reduced NOx) produced enhanced SO2 oxidation and an order-of-magnitude increase in particle nucleation in the plume despite the reduction in SO2 emissions. These results suggest that NOx emissions could strongly regulate particle nucleation and growth in power-plant plumes. Next, we test a range of cases with varying emissions to simulate the implementation of SO2 and NOx emissions-control technologies. Particle formation generally increases with SO2 emission, while NOx shows two different regimes: increasing particle formation with increasing NOx under low-NOx emissions and decreasing particle formation with increasing NOx under high-NOx emissions. Next, we compare model results with airborne measurements made in the W. A. Parish power-plant plume in 2000 and 2006, confirming the importance of NOx emissions on new particle formation and highlighting the substantial effect of background aerosol loadings on this process (the more polluted background of the 2006 case caused more than an order-of-magnitude reduction in particle formation in the plume compared to the cleaner test day in 2000). Finally, we calculate particle-formation statistics of 330 coal-fired power plants in the US in 1997 and 2010, and the model results show a median decrease of 19% in particle formation rates from 1997 to 2010 (whereas the W. A. Parish case study showed an increase). Thus, the US power plants, on average, show a different result than was found for the W. A. Parish plant specifically, and it shows that the strong NOx controls (90% reduction) implemented at the W. A. Parish plant (with relatively weak SO2 emissions reductions, 30%) are not representative of most power plants in the US during the past 15 yr. These results suggest that there may be important climate implications of power-plant controls due to changes in plume chemistry and microphysics, but the magnitude and sign of the aerosol changes depend greatly on the relative reductions in NOx and SO2 emissions in each plant. More extensive plume measurements for a range of emissions of SO2 and NOx and in varying background aerosol conditions are needed, however, to better quantify these effects.

scholarly journals The effect of coal-fired power-plant SO<sub>2</sub> and NO<sub>x</sub> control technologies on aerosol nucleation in the source plumes

2012 ◽  
Vol 12 (8) ◽  
pp. 19683-19713
Author(s):  
C. R. Lonsdale ◽  
R. G. Stevens ◽  
C. A. Brock ◽  
P. A. Makar ◽  
E. M. Knipping ◽  
...  
Keyword(s):  
Power Plant ◽  
Particle Formation ◽  
Atmospheric Modeling ◽  
Particle Nucleation ◽  
Nox Emissions ◽  
Aerosol Formation ◽  
So2 Emissions ◽  
Airborne Measurements ◽  
Wide Range ◽  
Control Technologies

Abstract. Nucleation in coal-fired power-plant plumes can greatly contribute to particle number concentrations near source regions. The changing emissions rates of SO2 and NOx due to pollution-control technologies over recent decades may have had a significant effect on aerosol formation and growth in the plumes, with ultimate implications for climate and human health. We use the System for Atmospheric Modeling (SAM) large-eddy simulation model with the TwO-Moment Aerosol Sectional (TOMAS) microphysics algorithm to model the nucleation in plumes of coal-fired plants. We test a range of cases with varying emissions to simulate the implementation of emissions-control technologies between 1997 and 2010. For the W.A. Parish power plant (near Houston, TX) during this time period, NOx emissions were reduced by ~90%, while SO2 emissions decreased by ~30%. Increases in plume OH (due to the reduced NOx) produced enhanced SO2 oxidation and particle nucleation despite the reduction in SO2 emissions. These results suggest that NOx emissions may strongly regulate particle nucleation and growth in power-plant plumes. Comparison of model results with airborne measurements made in the W.A. Parish power-plant plume in 2000 and 2006 confirm the importance of NOx emissions on new particle formation, yet also highlight the substantial effect of background aerosol loadings on this process. A wide range of NOx and SO2 emissions were modeled to understand how they affect particle formation in the plume. Particle formation generally increases with SO2 emission, while NOx shows two different regimes: increasing particle formation with increasing NOx under low-NOx emissions and decreasing particle formation with increasing NOx under high-NOx emissions. Finally, we calculate emissions statistics of 330 coal-fired power plants in the US in 1997 and 2010, and the model results show a median decrease of 19% in particle formation ratesfrom 1997 to 2010 (whereas the W.A. Parish case study showed an increase). These results suggest that there may be important climate implications of power-plant controls due to changes in plume chemistry and microphysics. More extensive plume measurements for a range of emissions of SO2 and NOx and in varying background aerosol conditions are needed to better quantify these effects.

scholarly journals Changes in Power Plant NOx Emissions over Northwest Greece Using a Data Assimilation Technique

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 900
Author(s):  
Ioanna Skoulidou ◽  
Maria-Elissavet Koukouli ◽  
Arjo Segers ◽  
Astrid Manders ◽  
Dimitris Balis ◽  
...  
Keyword(s):  
Power Plant ◽  
Data Assimilation ◽  
Energy Production ◽  
Power Plants ◽  
Transport Model ◽  
A Priori ◽  
Filter Method ◽  
Nox Emissions ◽  
A Posteriori ◽  
Data Assimilation Technique

In this work, we investigate the ability of a data assimilation technique and space-borne observations to quantify and monitor changes in nitrogen oxides (NOx) emissions over Northwestern Greece for the summers of 2018 and 2019. In this region, four lignite-burning power plants are located. The data assimilation technique, based on the Ensemble Kalman Filter method, is employed to combine space-borne atmospheric observations from the high spatial resolution Sentinel-5 Precursor (S5P) Tropospheric Monitoring Instrument (TROPOMI) and simulations using the LOTOS-EUROS Chemical Transport model. The Copernicus Atmosphere Monitoring Service-Regional European emissions (CAMS-REG, version 4.2) inventory based on the year 2015 is used as the a priori emissions in the simulations. Surface measurements of nitrogen dioxide (NO2) from air quality stations operating in the region are compared with the model surface NO2 output using either the a priori (base run) or the a posteriori (assimilated run) NOx emissions. Relative to the a priori emissions, the assimilation suggests a strong decrease in concentrations for the station located near the largest power plant, by 80% in 2019 and by 67% in 2018. Concerning the estimated annual a posteriori NOx emissions, it was found that, for the pixels hosting the two largest power plants, the assimilated run results in emissions decreased by ~40–50% for 2018 compared to 2015, whereas a larger decrease, of ~70% for both power plants, was found for 2019, after assimilating the space-born observations. For the same power plants, the European Pollutant Release and Transfer Register (E-PRTR) reports decreased emissions in 2018 and 2019 compared to 2015 (−35% and −38% in 2018, −62% and −72% in 2019), in good agreement with the estimated emissions. We further compare the a posteriori emissions to the reported energy production of the power plants during the summer of 2018 and 2019. Mean decreases of about −35% and−63% in NOx emissions are estimated for the two larger power plants in summer of 2018 and 2019, respectively, which are supported by similar decreases in the reported energy production of the power plants (~−30% and −70%, respectively).

Functional Analysis and Exergoeconomic Evaluation for the Combined Production of Electromechanical Power and Useful Heat of a Cogeneration Power Plant

2011 ◽  
Author(s):  
Washington Orlando Irrazabal Bohorquez ◽  
Joa˜o Roberto Barbosa
Keyword(s):  
Power Plant ◽  
Electricity Market ◽  
Sugar Cane ◽  
Power Plants ◽  
Hydroelectric Power Plant ◽  
Sugar Cane Bagasse ◽  
Fuel Oil ◽  
Hydroelectric Power ◽  
The Us ◽  
Electrical Generation

In the Ecuadorian electrical market, several sugar plants, which significantly participate in the local electricity market, are producing their own energy and commercializing the surplus to the electrical market. This study evaluates the integral use of the sugar cane bagasse for productive process on a Cogeneration Power Plant in an Ecuadorian Sugar Company [8]. The electrical generation based on biomass requires a great initial investment. The cost is around US$ 800/kW installed, twice the US$ 400/kW initial investment of conventional thermoelectric power plant and almost equal to the US$ 1,000/kW initial cost of hydroelectric power plant [5]. A thermoeconomic study was carried out on the production of electricity and the sales of the surplus of 27 MWe average produced by the power plant. An operational analysis was made using instantaneous values from the estimated curves of demand and generation of electricity. From the results, it was concluded that the generated electricity costs are 0.0443 US$/kWh, while the costs of the electricity from Fossil Power Plants (burning fuel oil, diesel fuel and natural gas) are in the range 0.03–0.15 US$/kWh and from Hydroelectric Plants are about 0.02 US$/kWh. Cogeneration power plants burning sugar cane bagasse could contribute to the mitigation of climatic change. This specific case study shows the reduction of the prospective emissions of greenhouse gases, around 55,188 ton of CO2 equivalent yearly for this cogeneration power plant.

Model-Based Analysis of the Start-Up Improvement of a CCPP due to Steam Turbine Warm-Keeping With Air

2019 ◽  
Author(s):  
Dennis Toebben ◽  
Tobias Burgard ◽  
Sebastian Berg ◽  
Manfred Wirsum ◽  
Liu Pei ◽  
...  
Keyword(s):  
Power Plant ◽  
Steam Turbine ◽  
Power Plants ◽  
Cold Start ◽  
Nox Emissions ◽  
Data Set ◽  
Water Steam ◽  
Hot Air ◽  
Start Up ◽  
Low Load

Abstract Combined cycle power plants (CCPP) have many advantages compared to other fossil power plants: high efficiency, flexible operation, compact design, high potential for combined heat and power (CHP) applications and fewer emissions. However, fuel costs are relatively high compared to coal. Nevertheless, major qualities such as high operation flexibility and low emissions distinctly increase in relevance in the future, due to rising power generation from renewable energy sources. An accelerated start-up procedure of CCPPs increases the flexibility and reduces the NOx-emissions, which are relatively high in gas turbine low load operation. Such low load operation is required during a cold start of a CCPP in order to heat up the steam turbine. Thus, a warm-keeping of the thermal-limiting steam turbine results in an accelerated start-up times as well as reduced NOx-emissions and lifetime consumption. This paper presents a theoretical analysis of the potential of steam turbine warm-keeping by means of hot air for a typical CCPP, located in China. In this method, the hot air passes through the steam turbine while the power plant is shut off which enables hot start conditions at any time. In order to investigate an improved start-up procedure, a physical based simplified model of the water-steam cycle is developed on the basis of an operation data set. This model is used to simulate an improved power plant start-up, in which the steam turbine remains hot after at least 120 hours outage. The results show a start-up time reduction of approximately two-thirds in comparison to a conventional cold start. Furthermore, the potential of steam turbine warm-keeping is discussed with regards to the power output, NOx-emissions, start-up costs and lifetime consumption.

scholarly journals Growth in NOx emissions from power plants in China: bottom-up estimates and satellite observations

2012 ◽  
Vol 12 (10) ◽  
pp. 4429-4447 ◽  
Author(s):  
S. W. Wang ◽  
Q. Zhang ◽  
D. G. Streets ◽  
K. B. He ◽  
R. V. Martin ◽  
...  
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Emission Inventory ◽  
Transport Model ◽  
Nox Emission ◽  
Nox Emissions ◽  
Large Power ◽  
Power Plant Emissions ◽  
Tropospheric No2 ◽  
Plant Emissions

Abstract. Using OMI (Ozone Monitoring Instrument) tropospheric NO2 columns and a nested-grid 3-D global chemical transport model (GEOS-Chem), we investigated the growth in NOx emissions from coal-fired power plants and their contributions to the growth in NO2 columns in 2005–2007 in China. We first developed a unit-based power plant NOx emission inventory for 2005–2007 to support this investigation. The total capacities of coal-fired power generation have increased by 48.8% in 2005–2007, with 92.2% of the total capacity additions coming from generator units with size ≥300 MW. The annual NOx emissions from coal-fired power plants were estimated to be 8.11 Tg NO2 for 2005 and 9.58 Tg NO2 for 2007, respectively. The modeled summer average tropospheric NO2 columns were highly correlated (R2 = 0.79–0.82) with OMI measurements over grids dominated by power plant emissions, with only 7–14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. The ratios of OMI-derived annual and summer average tropospheric NO2 columns between 2007 and 2005 indicated that most of the grids with significant NO2 increases were related to power plant construction activities. OMI had the capability to trace the changes of NOx emissions from individual large power plants in cases where there is less interference from other NOx sources. Scenario runs from GEOS-Chem model suggested that the new power plants contributed 18.5% and 10% to the annual average NO2 columns in 2007 in Inner Mongolia and North China, respectively. The massive new power plant NOx emissions significantly changed the local NO2 profiles, especially in less polluted areas. A sensitivity study found that changes of NO2 shape factors due to including new power plant emissions increased the summer average OMI tropospheric NO2 columns by 3.8–17.2% for six selected locations, indicating that the updated emission information could help to improve the satellite retrievals.

Clean Power From Coal: Design and Status of East Kentucky Power Cooperative’s E. A. Gilbert Unit

2005 ◽  
Author(s):  
Peter Treff ◽  
Craig Johnson
Keyword(s):  
Low Temperature ◽  
Catalytic Reduction ◽  
Nox Emissions ◽  
Residence Times ◽  
So2 Emissions ◽  
Gas Cleaning ◽  
Cleaning Equipment ◽  
The Us ◽  
Fluid Bed ◽  
Commercial Operation

East Kentucky Power Cooperative’s (EKPC) E. A. Gilbert unit promises to be one of the cleanest coal fired units in the US. Employing Circulating Fluid Bed (CFB) technology and innovative gas cleaning equipment from ALSTOM, this 268 MW unit will fire a variety of coals. The E. A. Gilbert unit is located at EKPC’s Spurlock Station alongside a 300 MW and a 500 MW pulverized coal unit that were built more than 20 years ago. Low SO2 emissions will be achieved by sulfation of limestone sorbent in the CFB and by additional sulfation of unreacted sorbent in the Flash Dryer AbsorberTM (FDA) system located downstream of the CFB. This will permit low SO2 emissions (0.2 lb/MM BTU, >95% removal). Very low NOx emissions (0.1 lb/MM BTU) are enabled by the low combustion temperatures of the CFB and by the use of selective non-catalytic reduction (SNCR). The latter employs the addition of anhydrous ammonia and extended residence times at low temperature to further reduce NOx within the boiler. Having broken ground in June of 2002, the unit is scheduled to begin firing coal in the winter of 2004–5, with commercial operation scheduled for spring, 2005. Its’ design features and status are the focus of this paper.

Multi-Pollutant Removal System Performance: Based on Testing and Plant Operation Experience

2006 ◽  
Author(s):  
H.-J. Hamel ◽  
Walter Jaeger ◽  
Volker Fattinger ◽  
Heinz Termuehlen
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Electric Power ◽  
System Performance ◽  
Power Plants ◽  
Fossil Fuel ◽  
Pollutant Removal ◽  
Clean Coal ◽  
The Us ◽  
Removal System

Since roughly 95 % of the fossil fuel reserves in the US are coal and only 5 % natural gas and crude oil, we need clean coal-fired power plants. Today, about 1400 pulverized-coal-fired power plant units are generating roughly 50 % of the US electric power.

scholarly journals A methodology to constrain carbon dioxide emissions from coal-fired power plants using satellite observations of co-emitted nitrogen dioxide

2020 ◽  
Vol 20 (1) ◽  
pp. 99-116 ◽  
Author(s):  
Fei Liu ◽  
Bryan N. Duncan ◽  
Nickolay A. Krotkov ◽  
Lok N. Lamsal ◽  
Steffen Beirle ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Co2 Emissions ◽  
Co2 Emission ◽  
Power Plants ◽  
Operating Conditions ◽  
Satellite Observations ◽  
Nox Emissions ◽  
Bottom Up ◽  
Monitoring Instrument ◽  
The Us

Abstract. We present a method to infer CO2 emissions from individual power plants based on satellite observations of co-emitted nitrogen dioxide (NO2), which could serve as complementary verification of bottom-up inventories or be used to supplement these inventories. We demonstrate its utility on eight large and isolated US power plants, where accurate stack emission estimates of both gases are available for comparison. In the first step of our methodology, we infer nitrogen oxides (NOx) emissions from US power plants using Ozone Monitoring Instrument (OMI) NO2 tropospheric vertical column densities (VCDs) averaged over the ozone season (May–September) and a “top-down” approach that we previously developed. Second, we determine the relationship between NOx and CO2 emissions based on the direct stack emissions measurements reported by continuous emissions monitoring system (CEMS) programs, accounting for coal quality, boiler firing technology, NOx emission control device type, and any change in operating conditions. Third, we estimate CO2 emissions for power plants using the OMI-estimated NOx emissions and the CEMS NOx∕CO2 emission ratio. We find that the CO2 emissions estimated by our satellite-based method during 2005–2017 are in reasonable agreement with the US CEMS measurements, with a relative difference of 8 %±41 % (mean ± standard deviation). The broader implication of our methodology is that it has the potential to provide an additional constraint on CO2 emissions from power plants in regions of the world without reliable emissions accounting. We explore the feasibility by comparing the derived NOx∕CO2 emission ratios for the US with those from a bottom-up emission inventory for other countries and applying our methodology to a power plant in South Africa, where the satellite-based emission estimates show reasonable consistency with other independent estimates. Though our analysis is limited to a few power plants, we expect to be able to apply our method to more US (and world) power plants when multi-year data records become available from new OMI-like sensors with improved capabilities, such as the TROPOspheric Monitoring Instrument (TROPOMI), and upcoming geostationary satellites, such as the Tropospheric Emissions: Monitoring Pollution (TEMPO) instrument.

scholarly journals Aerosol indirect forcing in a global model with particle nucleation

2009 ◽  
Vol 9 (1) ◽  
pp. 239-260 ◽  
Author(s):  
M. Wang ◽  
J. E. Penner
Keyword(s):  
Boundary Layer ◽  
Indirect Effects ◽  
Global Climate ◽  
Cloud Condensation Nuclei ◽  
Particle Formation ◽  
Particle Nucleation ◽  
So2 Emissions ◽  
Aerosol Indirect Effects ◽  
Aerosol Model ◽  
Indirect Forcing

Abstract. The number concentration of cloud condensation nuclei (CCN) formed as a result of anthropogenic emissions is a key uncertainty in the study of aerosol indirect forcing and global climate change. Here, we use a global aerosol model that includes an empirical boundary layer nucleation mechanism, the use of primary-emitted sulfate particles to represent sub-grid scale nucleation, as well as binary homogeneous nucleation to explore how nucleation affects the CCN concentration and the first aerosol indirect effect (AIE). The inclusion of the boundary layer nucleation scheme increases the global average CCN concentrations in the boundary layer by 31.4% when no primary-emitted sulfate particles are included and by 5.3% when they are included. Particle formation with the boundary layer nucleation scheme decreases the first indirect forcing over ocean, and increases the first indirect forcing over land when primary sulfate particles are included. This suggests that whether particle formation from aerosol nucleation increases or decreases aerosol indirect effects largely depends on the relative change of primary particles and SO2 emissions from the preindustrial to the present day atmosphere. Including primary-emitted sulfate particle significantly increases both the anthropogenic fraction of CCN concentrations and the first aerosol indirect forcing. The forcing from various treatments of aerosol nucleation ranges from −1.22 to −2.03 w/m2. This large variation shows the importance of better quantifying aerosol nucleation mechanisms for the prediction of CCN concentrations and aerosol indirect effects.

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