scholarly journals Boreal forest fire CO and CH<sub>4</sub> emission factors derived from tower observations in Alaska during the extreme fire season of 2015

2021 ◽  
Vol 21 (11) ◽  
pp. 8557-8574
Author(s):  
Elizabeth B. Wiggins ◽  
Arlyn Andrews ◽  
Colm Sweeney ◽  
John B. Miller ◽  
Charles E. Miller ◽  
...  
Keyword(s):  
Co2 Emission ◽  
Emission Factor ◽  
Emission Factors ◽  
Trace Gas ◽  
Fire Season ◽  
Ch4 Emission ◽  
Emission Ratio ◽  
Dry Biomass ◽  
The Mean ◽  
Co Emission

Abstract. Recent increases in boreal forest burned area, which have been linked with climate warming, highlight the need to better understand the composition of wildfire emissions and their atmospheric impacts. Here we quantified emission factors for CO and CH4 from a massive regional fire complex in interior Alaska during the summer of 2015 using continuous high-resolution trace gas observations from the Carbon in Arctic Reservoirs Vulnerability Experiment (CRV) tower in Fox, Alaska. Averaged over the 2015 fire season, the mean CO / CO2 emission ratio was 0.142 ± 0.051, and the mean CO emission factor was 127 ± 40 g kg−1 dry biomass burned. The CO / CO2 emission ratio was about 39 % higher than the mean of previous estimates derived from aircraft sampling of wildfires from boreal North America. The mean CH4 / CO2 emission ratio was 0.010 ± 0.004, and the CH4 emission factor was 5.3 ± 1.8 g kg−1 dry biomass burned, which are consistent with the mean of previous reports. CO and CH4 emission ratios varied in synchrony, with higher CH4 emission factors observed during periods with lower modified combustion efficiency (MCE). By coupling a fire emissions inventory with an atmospheric model, we identified at least 34 individual fires that contributed to trace gas variations measured at the CRV tower, representing a sample size that is nearly the same as the total number of boreal fires measured in all previous field campaigns. The model also indicated that typical mean transit times between trace gas emission within a fire perimeter and tower measurement were 1–3 d, indicating that the time series sampled combustion across day and night burning phases. The high CO emission ratio estimates reported here provide evidence for a prominent role of smoldering combustion and illustrate the importance of continuously sampling fires across time-varying environmental conditions that are representative of a fire season.

scholarly journals Evidence for a larger contribution of smoldering combustion to boreal forest fire emissions from tower observations in Alaska

2020 ◽  
Author(s):  
Elizabeth B. Wiggins ◽  
Arlyn Andrews ◽  
Colm Sweeney ◽  
John B. Miller ◽  
Charles E. Miller ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Co2 Emission ◽  
Emission Factor ◽  
Emission Factors ◽  
Trace Gas ◽  
Ch4 Emission ◽  
Fire Emissions ◽  
Emission Ratio ◽  
Dry Biomass ◽  
Co Emission

Abstract. With recent increases in burned area within boreal forests that have been linked to climate warming, there is a need to better understand the composition of emissions and their impact on atmospheric composition. Most previous studies have estimated boreal fire emission factors from daytime samples collected via aircraft near fire plumes or at the surface near actively burning fires. Here we quantified emission factors for CO and CH4 from a massive regional fire complex in interior Alaska during the summer of 2015 using continuous high-resolution trace gas observations from the CRV tower (Fox, AK). Averaged over the 2015 fire season, the CO/CO2 emission ratio was 0.138±0.048 and the CO emission factor was 145±50 g CO per kg of dry biomass consumed. The CO/CO2 emission ratio was about 35 % higher and more variable than most previous aircraft-based estimates for fresh wildfire emissions. The mean CH4/CO2 emission ratio was 0.010±0.003 and the CH4 emission factor was 6.05±2.09 g CH4 per kg of dry biomass consumed, with means similar to previous reports. CO and CH4 emission factors varied in synchrony, with higher CH4 emission factors observed during periods with lower modified combustion efficiency (MCE). By coupling a fire emissions inventory with an atmospheric model, we identified that at least 35 individual fires contributed to trace gas variations measured at the CRV tower, representing a significant increase in sampling compared to the number of boreal fires measured in all previous boreal forest fire work. The model also indicated that typical mean transit times between trace gas emission and tower measurement were 1–3 days, indicating that the time series sampled combustion across day and night burning phases. The high and variable CO emission factor estimates reported here provide evidence for a more prominent role of smoldering combustion, highlighting the importance of continuously sampling of fires across time-varying environmental conditions that are representative of typical burning conditions.

scholarly journals Analysis of Main Factors for CH4 Emission Factor Development in Manufacturing Industries and Construction Sector

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1220
Author(s):  
Seongmin Kang ◽  
Seonghum Cho ◽  
Joonyoung Roh ◽  
Eui-chan Jeon
Keyword(s):  
Emission Factor ◽  
Emission Factors ◽  
Ch4 Emission ◽  
Test Results ◽  
Intergovernmental Panel ◽  
Average Value ◽  
South Korean ◽  
National Characteristics ◽  
Lng Fuel ◽  
Model Year

This study has statistically analyzed the effect of boiler type and model year on CH4 emission factors, focusing on liquefied natural gas (LNG)—the most commonly used fuel in South Korean manufacturing combustion facilities. Samples were collected from the boilers of 39 manufacturing combustion facilities that use LNG fuel. The CH4 emission factors were developed based on 4 overhead fire-tube boilers, 14 once-through boilers, 14 vertical boilers with vertical water tubes, and 7 other boilers. This resulted in an average value of 0.11 CH4 kg/TJ, which is considerably lower than the Intergovernmental Panel on Climate Change (IPCC) 1996 guidelines(G/L) emission factor of 5 CH4 kg/TJ currently used in South Korea. In the Kruskal–Wallis test results, the significance probability was greater than 0.05 for the boiler types and ages, and there was no major difference in the average distributions, according to the boiler type or age. Therefore, according to the results of this study, the differences in the CH4 emission factors according to the boiler types and ages are not statistically large, and it was determined that there is no major difference even when the emission factors are applied to different fuel types. However, there was a major difference when the developed factors were compared to the CH4 emission factor proposed by the IPCC. Thus, there is a need to develop manufacturing combustion CH4 emission factors that reflect national characteristics.

scholarly journals Uncertainty Analysis for the CH4 Emission Factor of Thermal Power Plant by Monte Carlo Simulation

2018 ◽  
Vol 10 (10) ◽  
pp. 3448 ◽  
Author(s):  
Changsang Cho ◽  
Seongmin Kang ◽  
Minwook Kim ◽  
Yoonjung Hong ◽  
Eui-chan Jeon
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Emission Factor ◽  
Power Plants ◽  
Thermal Power ◽  
Emission Factors ◽  
Operating Conditions ◽  
Thermal Power Plants ◽  
Ch4 Emission ◽  
Uncertainty Range

Thermal power plants are a large source of greenhouse gas emissions among energy industry facilities. Emission factors for methane and nitrous oxide depend on combustion technologies and operating conditions and vary significantly with individual thermal power plants. Due to this variability, use of average emission factors for these gases will introduce relatively large uncertainties. This study determined the CH4 emission factors of thermal power plants currently in operation in Korea by conducting field investigations according to fuel type and type of combustion technique. Through use of the Monte Carlo simulation, the uncertainty range for the CH4 emission factor was determined. The estimation showed, at the 95% confidence level, that the uncertainty range for CH4 emission factor from a tangential firing boiler using bituminous coal was −46.6% to +145.2%. The range for the opposed wall-firing boiler was −25.3% to +70.9%. The range for the tangential firing boiler using fuel oil was −39.0% to 93.5%, that from the opposed wall-firing boiler was −47.7% to +201.1%, and that from the internal combustion engine boiler was −38.7% to +106.1%. Finally, the uncertainty range for the CH4 emission factor from the combined cycle boiler using LNG was −90% to +326%.

scholarly journals Uncertainty of the Electricity Emission Factor Incorporating the Uncertainty of the Fuel Emission Factors

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5697
Author(s):  
Kun Mo LEE ◽  
Min Hyeok LEE
Keyword(s):  
Power Generation ◽  
Emission Factor ◽  
Bootstrap Method ◽  
Ghg Emissions ◽  
Original Data ◽  
Emission Factors ◽  
Ghg Emission ◽  
Data Set ◽  
The Mean ◽  
The Bootstrap Method

Greenhouse gas (GHG) emission from electricity generation has been recognized as one of the most significant contributors to global warming. The GHG emission factor of electricity (hereafter, electricity emission factor) can be expressed as a function of three different (average, minimum, and maximum) fuel emission factors, monthly fuel consumption, and monthly net power generation. Choosing the average fuel emission factor over the minimum and maximum fuel emission factors is the cause of uncertainty in the electricity emission factor, and thus GHG emissions of the power generation. The uncertainties of GHG emissions are higher than those of the electricity emission factor, indicating that the uncertainty of GHG emission propagates in the GHG emission computation model. The bootstrapped data were generated by applying the bootstrap method to the original data set which consists of a 60-monthly average, and minimum and maximum electricity emission factors. The bootstrapped data were used for computing the mean, confidence interval (CI), and percentage uncertainty (U) of the electricity emission factor. The CI, mean, and U were [0.431, 0.443] kg CO2-eq/kWh, 0.437 kg CO2-eq/kwh, and 2.56%, respectively.

scholarly journals Major Elements to Consider in Developing Ammonia Emission Factor at Municipal Solid Waste (MSW) Incinerators

2021 ◽  
Vol 13 (4) ◽  
pp. 2197
Author(s):  
Seongmin Kang ◽  
Joonyoung Roh ◽  
Eui-chan Jeon
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Emission Factor ◽  
Waste Incineration ◽  
Emission Factors ◽  
Major Elements ◽  
Ammonia Emission ◽  
Nh3 Emission ◽  
The Difference ◽  
The One

NH3 is one of the major substances contributing to the secondary generation of PM2.5; therefore, management is required. In Korea, the management of NH3 is insufficient, and the emission factor used by EPA is the same as the one used when calculating emissions. In particular, waste incineration facilities do not currently calculate NH3 emissions. In the case of combustion facilities, the main ammonia emission source is the De-NOx facility, and, in the case of a power plant with a De-NOx facility, NH3 emission is calculated. Therefore, in the case of a Municipal Solid Waste (MSW) incinerator with the same facility installed, it is necessary to calculate NH3 emissions. In this study, the necessity of developing NH3 emission factors for an MSW incinerator and calculating emission was analyzed. In addition, elements to be considered when developing emission factors were analyzed. The study found that the NH3 emission factors for each MSW incinerator technology were calculated as Stoker 0.010 NH3 kg/ton and Fluidized Beds 0.004 NH3 kg/ton, which was greater than the NH3 emission factor 0.003 NH3 kg/ton for the MSW incinerator presented in EMEP/EEA (2016). As a result, it was able to identify the need for the development of NH3 emission factors in MSW incinerators in Korea. In addition, the statistical analysis of the difference between the incineration technology of MSW and the NH3 emission factor by the De-NOx facility showed a difference in terms of both incineration technology and De-NOx facilities, indicating that they should be considered together when developing the emission factor. In addition to MSW, it is believed that it will be necessary to review the development of emission factors for waste at workplaces and incineration facilities of sewage sludge.

Methane emissions from young and mature dairy cattle

2016 ◽  
Vol 56 (11) ◽  
pp. 1897 ◽  
Author(s):  
C. A. Ramírez-Restrepo ◽  
H. Clark ◽  
S. Muetzel
Keyword(s):  
New Zealand ◽  
Emission Factor ◽  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Dry Matter Intake ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Age Related ◽  
The Mean

Daily methane (CH4) emissions (g) and CH4 yield (g/kg dry matter intake) were measured from 10 dairy heifers (<1 year old) and nine rumen-fistulated cows (>6 years old) fed ryegrass (Lolium perenne) chaffage indoors. The CH4 emissions were estimated using the sulfur hexafluoride tracer technique in four ~5-day periods beginning in June 2008 and repeated 4, 6 and 7 months later. Respiratory chambers were used in four ~13-day periods beginning in November 2008 and repeated 2, 5 and 6 months later. Third and fourth sulfur hexafluoride tracer periods overlapped with the first and second chamber measurement periods, respectively. Averaged over the four measurement periods the CH4 yields determined using both techniques were similar for heifers and cows. The mean CH4 yield estimated by the sulfur hexafluoride tracer technique was 25.3 ± 0.52 for heifers and 24.1 ± 0.55 for mature cows, whereas the mean CH4 yield measured in respiratory chambers was 23.7 ± 0.66 for heifers and 23.6 ± 0.66 for mature cows. Averaged over the eight measurements irrespective of technique, CH4 yields for heifers (24.5 ± 0.42) and cows (23.8 ± 0.43) were similar. There was also no difference between CH4 methods for assessing CH4 yield during the overlapping measurement periods. It was concluded that no consistent differences in CH4 yield existed between heifers and mature cows. Therefore, we do not recommend adoption of an age-related emission factor for cattle in the national inventory calculations for New Zealand.

scholarly journals Groundwater N<sub>2</sub>O emission factors of nitrate-contaminated aquifers as derived from denitrification progress and N<sub>2</sub>O accumulation

2008 ◽  
Vol 5 (5) ◽  
pp. 1215-1226 ◽  
Author(s):  
D. Weymann ◽  
R. Well ◽  
H. Flessa ◽  
C. von der Heide ◽  
M. Deurer ◽  
...  
Keyword(s):  
Emission Factor ◽  
Noble Gas ◽  
N2o Emission ◽  
Emission Factors ◽  
N2o Emissions ◽  
Northern Germany ◽  
Stable Component ◽  
Sand And Gravel ◽  
First Time ◽  
Ipcc Default

Abstract. We investigated the dynamics of denitrification and nitrous oxide (N2O) accumulation in 4 nitrate (NO−3) contaminated denitrifying sand and gravel aquifers of northern Germany (Fuhrberg, Sulingen, Thülsfelde and Göttingen) to quantify their potential N2O emission and to evaluate existing concepts of N2O emission factors. Excess N2 – N2 produced by denitrification – was determined by using the argon (Ar) concentration in groundwater as a natural inert tracer, assuming that this noble gas functions as a stable component and does not change during denitrification. Furthermore, initial NO−3 concentrations (NO−3 that enters the groundwater) were derived from excess N2 and actual NO−3 concentrations in groundwater in order to determine potential indirect N2O emissions as a function of the N input. Median concentrations of N2O and excess N2 ranged from 3 to 89 μg N L−1 and from 3 to 10 mg N L−1, respectively. Reaction progress (RP) of denitrification was determined as the ratio between products (N2O-N + excess N2) and starting material (initial NO−3 concentration) of the process, characterizing the different stages of denitrification. N2O concentrations were lowest at RP close to 0 and RP close to 1 but relatively high at a RP between 0.2 and 0.6. For the first time, we report groundwater N2O emission factors consisting of the ratio between N2O-N and initial NO−3-N concentrations (EF1). In addition, we determined a groundwater emission factor (EF2) using a previous concept consisting of the ratio between N2O-N and actual NO−3-N concentrations. Depending on RP, EF(1) resulted in smaller values compared to EF(2), demonstrating (i) the relevance of NO−3 consumption and consequently (ii) the need to take initial NO−3-N concentrations into account. In general, both evaluated emission factors were highly variable within and among the aquifers. The site medians ranged between 0.00043–0.00438 for EF(1) and 0.00092–0.01801 for EF(2), respectively. For the aquifers of Fuhrberg and Sulingen, we found EF(1) median values which are close to the 2006 IPCC default value of 0.0025. In contrast, we determined significant lower EF values for the aquifers of Thülsfelde and Göttingen. Summing the results up, our study supports the substantial downward revision of the IPCC default EF5-g from 0.015 (1997) to 0.0025 (2006).

scholarly journals EMISSÃO DE CO2, ATRIBUTOS FÍSICOS E CARBONO ORGÂNICO TOTAL EM DIFERENTES SISTEMAS DE PREPARO DO SOLO

Nativa ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 494
Author(s):  
Carla Da Penha Simon ◽  
Edney Leandro da Vitória ◽  
Elcio Das Graça Lacerda ◽  
Yago Soares Avancini ◽  
Tatiana Fiorotti Rodrigues ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Co2 Emission ◽  
Conventional Tillage ◽  
No Tillage ◽  
Minimum Tillage ◽  
Soil Preparation ◽  
Physical Attributes ◽  
The Mean ◽  
Box Plot

Objetivou-se quantificar o CO2,atributos químicos e físicos do solo são influenciados por diferentes manejos de preparo do solo. O Delineamento experimental adotado foi inteiramente casualizado, sendo os tratamentos: Sistema de Plantio Direto (SPD), Cultivo Mínimo e Preparo Convencional (PC), e como referência: área de vegetação nativa (Mata), contando com seis repetições cada variável de estudo. Além da comparação por teste médias, foi realizada uma análise exploratória das leituras nos sistemas de preparo do solo, onde o CO2 foi traduzido graficamente num diagrama o box-plot. As variáveis avaliadas foram: CO2 obtido por meio de um analisador de gás infravermelho; os atributos físicos do solo: Densidade do solo (Ds), Volume Total de Poros (VTP), Macroporosidade (Ma), Microporosidade (Mi), Resistência a Penetração do solo (RPS) e o atributo químico: carbono orgânico total (COT). O fluxo CO2 do solo apresentou diferença significativa entre o SPD e o PC; valores médios encontrados para SPD, CM, Mata e PC foram 2,30; 2,25; 2,18; e 1,39 μmolCO2m−2 s−1, respectivamente; o COT apresentou seu maior valor na área de Mata (32,95 gkg-1) diferindo estatisticamente das demais áreas. Observou-se uma menor emissão de CO2 do solo no PC, pois o sistema apresenta baixo aporte de carbono orgânico.Palavras-chave: sistema de preparo convencional; cultivo mínimo; preparo convencional; carbono orgânico total. CO2 EMISSION, PHYSICAL ATTRIBUTES AND TOTAL ORGANIC CARBON IN DIFFERENT SOIL PREPARATION SYSTEMS ABSTRACT: The objective was to quantify the CO2, chemical and physical attributes of the soil are influenced by different management of soil preparation. The experimental design was completely randomized, with the treatments: no-tillage (NT), minimum tillage (MT) and conventional tillage (CT), and as reference:  native forest (NF), with six replicates each study variable. In addition to the mean test comparison, an exploratory analysis of the readings was performed in the soil preparation systems, where CO2 was graphically translated into a box-plot diagram. The variables evaluated were: CO2 obtained by means of a infrared gas analyzer; density (Bd), total pore volume (TPV), macroporosity (Ma), microporosity (Mi), resistance to soil penetration (RSP) and chemical attribute: total organic carbon (TOC). The CO2 soil flux presented a significant difference between NT and CT; where respectively the mean values found for SPD, CM, Mata and PC were 2.30; 2.25; 2.18; and 1.39 μmolCO2m-2s-1; the COT had its highest value in the Mata area (32.95 gkg-1), differing statistically from the other areas. It was observed a lower CO2 emission of the soil in the PC, because the system has low input of organic carbon.Keywords: no-tillage; conventional tillage; minimum tillage; total organic carbon.

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