scholarly journals Comparison of source apportionment approaches and analysis of non-linearity in a real case model application

2021 ◽  
Author(s):  
Claudio A. Belis ◽  
Guido Pirovano ◽  
Maria Gabriella Villani ◽  
Giuseppe Calori ◽  
Nicola Pepe ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Emission Reduction ◽  
Decomposition Analysis ◽  
Road Transport ◽  
Base Case ◽  
Emission Reductions ◽  
Interaction Terms ◽  
Residential Combustion ◽  
Different Sources ◽  
Source Allocation

Abstract. The response of particulate matter (PM) concentrations to emission reductions was analysed by assessing the results obtained with two different source apportionment approaches. The brute force (BF) method source impacts, computed at various emission reduction levels using two chemical transport models (CAMx and FARM), were compared with the contributions obtained with the tagged species (TS) approach (CAMx with PSAT module). The study focused on the main sources of secondary inorganic aerosol precursors in the Po Valley (Northern Italy): agriculture, road transport, industry and residential combustion. The interaction terms between different sources obtained from a factor decomposition analysis were used as indicators of non-linear PM10 concentration responses to individual source emission reductions. Moreover, such interaction terms were analysed in the light of the free ammonia/total nitrate gas ratio to determine the relationships between the chemical regime and the non-linearity at selected sites. The impacts of the different sources were not proportional to the emission reductions and such non-linearity was most relevant for 100 % emission reduction levels compared with smaller reduction levels (50 % and 20 %). Such differences between emission reduction levels were connected to the extent to which they modify the chemical regime in the base case. Non-linearity was mainly associated with agriculture and the interaction of this source with road transport and, to a lesser extent, with industry. Actually, the mass concentration of PM10 allocated to agriculture by TS and BF approaches were significantly different when a 100 % emission reduction was applied. However, in many situations the non-linearity in PM10 annual average source allocation was negligible and the TS and the BF approaches provided comparable results. PM mass concentrations attributed to the same sources by TS and BF were highly comparable in terms of spatial patterns and quantification of the source allocation for industry, transport and residential combustion. The conclusions obtained in this study for PM10 are also applicable to PM2.5.

scholarly journals Comparison of source apportionment approaches and analysis of non-linearity in a real case model application

2021 ◽  
Vol 14 (7) ◽  
pp. 4731-4750
Author(s):  
Claudio A. Belis ◽  
Guido Pirovano ◽  
Maria Gabriella Villani ◽  
Giuseppe Calori ◽  
Nicola Pepe ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Emission Reduction ◽  
Road Transport ◽  
Base Case ◽  
Emission Reductions ◽  
Interaction Terms ◽  
Residential Combustion ◽  
Different Sources ◽  
Mass Concentrations ◽  
Source Allocation

Abstract. The response of particulate matter (PM) concentrations to emission reductions was analysed by assessing the results obtained with two different source apportionment approaches. The brute force (BF) method source impacts, computed at various emission reduction levels using two chemical transport models (CAMx and FARM), were compared with the contributions obtained with the tagged species (TS) approach (CAMx with the PSAT module). The study focused on the main sources of secondary inorganic aerosol precursors in the Po Valley (northern Italy): agriculture, road transport, industry and residential combustion. The interaction terms between different sources obtained from a factor decomposition analysis were used as indicators of non-linear PM10 concentration responses to individual source emission reductions. Moreover, such interaction terms were analysed in light of the free ammonia / total nitrate gas ratio to determine the relationships between the chemical regime and the non-linearity at selected sites. The impacts of the different sources were not proportional to the emission reductions, and such non-linearity was most relevant for 100 % emission reduction levels compared with smaller reduction levels (50 % and 20 %). Such differences between emission reduction levels were connected to the extent to which they modify the chemical regime in the base case. Non-linearity was mainly associated with agriculture and the interaction of this source with road transport and, to a lesser extent, with industry. Actually, the mass concentrations of PM10 allocated to agriculture by the TS and BF approaches were significantly different when a 100 % emission reduction was applied. However, in many situations the non-linearity in PM10 annual average source allocation was negligible, and the TS and BF approaches provided comparable results. PM mass concentrations attributed to the same sources by TS and BF were highly comparable in terms of spatial patterns and quantification of the source allocation for industry, transport and residential combustion. The conclusions obtained in this study for PM10 are also applicable to PM2.5.

Numerical Optimization of WAG Injection in a Sandstone Field using a Coupled Surface and Subsurface Model

2021 ◽  
Author(s):  
Thaer I. Ismail ◽  
Emad W. Al-Shalabi ◽  
Mahmoud Bedewi ◽  
Waleed AlAmeri
Keyword(s):  
Oil Recovery ◽  
Gas Injection ◽  
Coupled Model ◽  
Sensitivity Study ◽  
Mobility Control ◽  
Base Case ◽  
The North ◽  
Injection Process ◽  
Interaction Terms ◽  
Wag Injection

Abstract Gas injection is one of the most commonly used enhanced oil recovery (EOR) methods. However, there are multiple problems associated with gas injection including gravity override, viscous fingering, and channeling. These problems are due to an adverse mobility ratio and cause early breakthrough of the gas resulting, in poor recovery efficiency. A Water Alternating Gas (WAG) injection process is recommended to resolve these problems through better mobility control of gas, leading to better project economics. However, poor WAG design and lack of understanding of the different factors that control its performance might result in unfavorable oil recovery. Therefore, this study provides more insight into improving WAG oil recovery by optimizing different surface and subsurface WAG parameters using a coupled surface and subsurface simulator. Moreover, the work investigates the effects of hysteresis on WAG performance. This case study investigates a field named Volve, which is a decommissioned sandstone field in the North Sea. Experimental design of factors influencing WAG performance on this base case was studied. Sensitivity analysis was performed on different surface and subsurface WAG parameters including WAG ratio, time to start WAG, total gas slug size, cycle slug size, and tubing diameter. A full two-level factorial design was used for the sensitivity study. The significant parameters of interest were further optimized numerically to maximize oil recovery. The results showed that the total slug size is the most important parameter, followed by time to start WAG, and then cycle slug size. WAG ratio appeared in some of the interaction terms while tubing diameter effect was found to be negligible. The study also showed that phase hysteresis has little to no effect on oil recovery. Based on the optimization, it is recommended to perform waterflooding followed by tertiary WAG injection for maximizing oil recovery from the Volve field. Furthermore, miscible WAG injection resulted in an incremental oil recovery between 5 to 11% OOIP compared to conventional waterflooding. WAG optimization is case-dependent and hence, the findings of this study hold only for the studied case, but the workflow should be applicable to any reservoir. Unlike most previous work, this study investigates WAG optimization considering both surface and subsurface parameters using a coupled model.

scholarly journals Research on China’s embodied carbon import and export trade from the perspective of value-added trade

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0258902
Author(s):  
Guangyao Deng ◽  
Fengying Lu ◽  
Xiaofang Yue
Keyword(s):  
Emission Reduction ◽  
Decomposition Analysis ◽  
Value Added ◽  
The United States ◽  
Export Trade ◽  
Structural Decomposition Analysis ◽  
Structural Decomposition ◽  
Embodied Carbon ◽  
Production And Consumption ◽  
Import And Export

The development of globalization has separated the production and consumption of products spatially, and the international trade of products has become a carrier of embodied carbon trade. This paper adopted the perspective of value-added trade to calculate the amount of embodied carbon trade of China from 2006 to 2015 and perform a structural decomposition analysis of the changes in China’s embodied carbon trade. This study found that: (1) China’s embodied carbon exports are much larger than its embodied carbon imports, and there are differences between countries. China imported the largest amount of embodied carbon from South Korea, and it exported the largest amount of embodied carbon to the United States. (2) The structural decomposition analysis shows that changes in the value-added carbon emission coefficient during the study period would have caused China’s embodied carbon trade to decrease, and changes in value-added trade would have caused China’s embodied carbon trade to increase. Therefore, countries trading with China need to strengthen their cooperation with China in energy conservation, emission reduction, and product trade. In order to accurately reflect China’s embodied carbon trade, it is necessary to calculate embodied carbon trade from the perspective of value-added trade.

scholarly journals Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City

2009 ◽  
Vol 9 (1) ◽  
pp. 39-55 ◽  
Author(s):  
M. Zavala ◽  
W. Lei ◽  
M. J. Molina ◽  
L. T. Molina
Keyword(s):  
Mexico City ◽  
Emission Control ◽  
Emission Factors ◽  
Nox Emission ◽  
Base Case ◽  
Mobile Source ◽  
Historical Trends ◽  
Emission Reductions ◽  
Control Policies ◽  
The Past

Abstract. The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio. This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM) and the standard Brute Force Method (BFM) in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with NOx emission reductions and decrease linearly with VOC emission reductions only up to 30% from the base case. We further performed emissions perturbations from the gasoline fleet, diesel fleet, all mobile (gasoline plus diesel) and all emission sources (anthropogenic plus biogenic). The results suggest that although large ozone reductions obtained in the past were from changes in emissions from gasoline vehicles, currently significant benefits could be achieved with additional emission control policies directed to regulation of VOC emissions from diesel and area sources that are high emitters of alkenes, aromatics and aldehydes.

scholarly journals Reducing China’s road transport sector CO2 emissions to 2050: Technologies, costs and decomposition analysis

2015 ◽  
Vol 157 ◽  
pp. 905-917 ◽  
Author(s):  
Ajay Gambhir ◽  
Lawrence K.C. Tse ◽  
Danlu Tong ◽  
Ricardo Martinez-Botas
Keyword(s):  
Co2 Emissions ◽  
Decomposition Analysis ◽  
Road Transport ◽  
Transport Sector

scholarly journals Source Contributions to Rural Carbonaceous Winter Aerosol in North-Eastern Poland

Atmosphere ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 263 ◽  
Author(s):  
Adam Kristensson ◽  
Stina Ausmeel ◽  
Julija Pauraite ◽  
Axel Eriksson ◽  
Erik Ahlberg ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Aerosol Particles ◽  
Road Transport ◽  
Carbonaceous Aerosol ◽  
Monitoring Site ◽  
Journal Articles ◽  
Wood Combustion ◽  
Combustion Source ◽  
Source Contributions ◽  
North Eastern

Concentrations of aerosol particles in Poland and their sources are rarely discussed in peer-reviewed journal articles despite serious air quality issues. A source apportionment of carbonaceous aerosol particles was performed during winter at a rural background environment field site in north-eastern Poland. Data were used of light absorption at seven wavelengths and levoglucosan concentrations along existing monitoring of PM2.5, organic carbon and elemental carbon (OC/EC) at the Diabła Góra EMEP monitoring site between January 17 and March 19 during the EMEP intensive winter campaign of 2018. Average PM2.5, OC, EC, equivalent black carbon (eBC) and levoglucosan concentrations and standard deviations amounted to 18.5 ± 9.3, 4.5 ± 2.5, 0.57 ± 0.28, 1.04 ± 0.62 and 0.134 ± 0.084 µg m−3 respectively. Various tools for source apportionment were used to obtain a source contribution to carbonaceous matter (CM) with three components. The wood combustion source component contributed 1.63 µg m−3 (21%), domestic coal combustion 3.3 µg m−3 (41%) and road transport exhaust 2.9 µg m−3 (38%). Similar levels and temporal variability were found for the nearby Lithuanian site of Preila, corroborating the Polish results.

scholarly journals What Factors Drive Air Pollutants in China? An Analysis from the Perspective of Regional Difference Using a Combined Method of Production Decomposition Analysis and Logarithmic Mean Divisia Index

2019 ◽  
Vol 11 (17) ◽  
pp. 4650 ◽  
Author(s):  
Xu ◽  
Miao ◽  
Li ◽  
Zhou ◽  
Ma ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Emission Reduction ◽  
Northeast China ◽  
Decomposition Analysis ◽  
Inhibitory Effect ◽  
Central China ◽  
Substitution Effects ◽  
Logarithmic Mean ◽  
Energy Substitution ◽  
Technology Improvement

Air pollution in China attracts the world’s attention, so it is important to study its driving factors for air pollutants. The combined Production Decomposition Analysis and Logarithmic Mean Divisia Index (PDA–LMDI) model is applied to construct a regional contribution index in this study to explore the regional differences in factors affecting sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter with diameter not greater than 2.5 µm (PM2.5) from 2005 to 2015 in China. The regional emission coefficient had a great inhibitory effect, which reduced SO2, NOx, and PM2.5 by 25,364.9, 10,449.3, and 11,295.3 kilotons (kt) from 2005 to 2015, respectively. For this inhibitory effect, the degree to emission reduction was great for North and East China, followed by South and Central China, and small for Southwest. Northwest. and Northeast China. The regional technical efficiency, technology improvement, capital-energy substitution and labor-energy substitution effects each reduced SO2, NOx, and PM2.5 by about 3500, 3100, and 1500 kt from 2005 to 2015, respectively. For the regional technical efficiency and technology improvement effects, the degree to emission reduction was great in East and Central China, and small in South Northwest and Northeast China. For the regional capital- and labor-energy substitution effects, the degree of emission reduction was great for North East and Central China, and small for Northwest and South China. The regional output proportion effect increased SO2, NOx, and PM2.5 by 1211.2, 320.1, and 277.8 kt from 2005 to 2015, respectively. The national economic growth had a relatively great promoting effect and increased SO2, NOx, and PM2.5 by 26,445.5, 23,827.5, and 11,925.5 kt from 2005 to 2015, respectively. Each region should formulate relevant policies and measures for emission reduction according to local conditions.

scholarly journals Source apportionment of highly time resolved trace elements during a firework episode from a rural freeway site in Switzerland

2019 ◽  
Author(s):  
Pragati Rai ◽  
Markus Furger ◽  
Jay Slowik ◽  
Francesco Canonaco ◽  
Roman Fröhlich ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Air Pollutants ◽  
Road Dust ◽  
Sea Salt ◽  
Positive Matrix ◽  
Time Resolved ◽  
Transient Sources ◽  
Elemental Mass ◽  
Pm10 Mass ◽  
Different Sources

Abstract. Trace element measurements in PM10 were performed with 1 h time resolution at a rural freeway site during summer 2015 in Switzerland using the Xact multi-metals monitor. On average the Xact 625 elements (without accounting for oxygen and other associated elements) make up about 20 % of the total PM10 mass (14.6 µg m−3). Subsequently, a source apportionment by positive matrix factorization (PMF) implemented via the Source Finder software (SoFi Pro) was applied. Eight different sources were identified (notable elements in brackets) for PM10: fireworks-I (K, S, Ba, Cl), fireworks-II (K), sea salt (Cl), secondary sulfate (S), background dust (Si, Ti), road dust (Ca), traffic-related (Fe) and industrial (Zn, Pb). The major components were secondary sulfate and traffic-related followed by background dust and road dust factors, explaining 21 %, 20 %, 18 % and 16 % of the analysed PM10 elemental mass, respectively, with the factor mass not corrected for oxygen content. Further, there are minor contributions (on the order of a few percent) of sea salt and industrial sources. The regionally influenced secondary sulfate factor experiences negligible resuspension, and concentrations are similar throughout the day. The significant loads of the traffic-related and road dust factors with strong diurnal variations highlight the continuing importance of vehicle-related air pollutants at this site. Enhanced control of PMF using SoFi Pro allowed for a successful apportionment of transient sources such as the two firework factors and sea salt, which remained mixed when analysed by unconstrained PMF.

scholarly journals Twenty-five years of continuous sulphur dioxide emission reduction in Europe

2007 ◽  
Vol 7 (13) ◽  
pp. 3663-3681 ◽  
Author(s):  
V. Vestreng ◽  
G. Myhre ◽  
H. Fagerli ◽  
S. Reis ◽  
L. Tarrasón
Keyword(s):  
Long Range ◽  
Emission Reduction ◽  
Western Europe ◽  
European Countries ◽  
Emission Data ◽  
Individual Country ◽  
Emission Reductions ◽  
Sulphur Emissions ◽  
Sulphur Emission ◽  
Gothenburg Protocol

Abstract. During the last twenty-five years European emission data have been compiled and reported under the Cooperative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (EMEP) as part of the work under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP). This paper presents emission trends of SO2 reported to EMEP and validated within the programme for the period 1980–2004. These European anthropogenic sulphur emissions have been steadily decreasing over the last twenty-five years, amounting from about 55 Tg SO2 in 1980 to 15 Tg SO2 in 2004. The uncertainty in sulphur emission estimates for individual countries and years are documented to range between 3% and 25%. The relative contribution of European emissions to global anthropogenic sulphur emissions has been halved during this period. Based on annual emission reports from European countries, three emission reduction regimes have been identified. The period 1980–1989 is characterized by low annual emission reductions (below 5% reduction per year and 20% for the whole period) and is dominated by emission reductions in Western Europe. The period 1990–1999 is characterised by high annual emission reductions (up to 11% reduction per year and 54% for the whole period), most pronounced in Central and Eastern Europe. The annual emission reductions in the period 2000–2004 are medium to low (below 6% reduction per year and 17% for the whole period) and reflect the unified Europe, with equally large reductions in both East and West. The sulphur emission reduction has been largest in the sector Combustion in energy and transformation industries, but substantial decreases are also seen in the Non-industrial combustion plants together with the sectors Industrial combustion and Industrial production processes. The majority of European countries have reduced their emissions by more than 60% between 1990 and 2004, and one quarter have already achieved sulphur emission reductions higher than 80%. At European level, the total sulphur target for 2010 set in the Gothenburg Protocol (16 Tg) has apparently already been met by 2004. However, still half of the Parties to the Gothenburg Protocol have to reduce further their sulphur emissions in order to attain their individual country total emission targets for 2010. It is also noteworthy that, contrasting the Gothenburg Protocol requirements, a growing number of countries have recently been reporting increasing sulphur emissions, while others report only minor further decreases. The emission trends presented here are supported by different studies of air concentrations and depositions carried out within and outside the framework of the LRTAP Convention.

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