scholarly journals On the Theoretical CO2 Sequestration Potential of Pervious Concrete

2019 ◽  
Vol 4 (1) ◽  
pp. 12 ◽  
Author(s):  
Ethan Ellingboe ◽  
Jay Arehart ◽  
Wil Srubar
Keyword(s):  
Co2 Emissions ◽  
Co2 Sequestration ◽  
Pervious Concrete ◽  
Theoretical Formulation ◽  
Concrete Mixtures ◽  
Sequestration Potential ◽  
Carbon Dioxide Co2 ◽  
New Applications ◽  
Natural Carbonation

Pervious concrete, which has recently found new applications in buildings, is both energy- and carbon-intensive to manufacture. However, similar to normal concrete, some of the initial CO2 emissions associated with pervious concrete can be sequestered through a process known as carbonation. In this work, the theoretical formulation and application of a mathematical model for estimating the carbon dioxide (CO2) sequestration potential of pervious concrete is presented. Using principles of cement and carbonation chemistry, the model related mixture proportions of pervious concretes to their theoretical in situ CO2 sequestration potential. The model was subsequently employed in a screening life cycle assessment (LCA) to quantify the percentage of recoverable CO2 emissions—namely, the ratio of in situ sequesterable CO2 to initial cradle-to-gate CO2 emissions—for common pervious concrete mixtures. Results suggest that natural carbonation can recover up to 12% of initial CO2 emissions and that CO2 sequestration potential is maximized for pervious concrete mixtures with (i) lower water-to-cement ratios, (ii) higher compressive strengths, (iii) lower porosities, and (iv) lower hydraulic conductivities. However, LCA results elucidate that mixtures with maximum CO2 sequestration potential (i.e., mixtures with high cement contents and CO2 recoverability) emit more CO2 from a net-emissions perspective, despite their enhanced in situ CO2 sequestration potential.

scholarly journals Effects of Accelerated Carbonation Testing and by-Product Allocation on the CO2-Sequestration-to-Emission Ratios of Fly Ash-Based Binder Systems

2021 ◽  
Vol 11 (6) ◽  
pp. 2781
Author(s):  
Philip Van den Heede ◽  
Nele De Belie
Keyword(s):  
Fly Ash ◽  
Co2 Emissions ◽  
Co2 Sequestration ◽  
High Volume ◽  
Electricity Production ◽  
Cement Clinker ◽  
Economic Allocation ◽  
High Volume Fly Ash ◽  
Sequestration Potential ◽  
Natural Carbonation

Carbonation of cementitious binders implies gradual capture of CO2 and significant compensation for the abundant cement-related CO2 emissions. Therefore, one should always look at the CO2-sequestration-to-emission ratio (CO2SP/EM). Here, this was done for High-Volume Fly Ash (HVFA) mortar (versus two commercial cement mortars). Regarding their CO2 sequestration potential, effects of accelerated testing (at 1–10% CO2) on as such estimated natural carbonation degrees and rates were studied. Production related CO2 emissions were evaluated using life cycle assessment with no/economic allocation for fly ash. Natural carbonation rates estimated from accelerated tests significantly underestimate actual natural carbonation rates (with 29–59% for HVFA mortar) while corresponding carbonation degrees are significantly overestimated (67–74% as opposed to the actual 58% for HVFA mortar). It is advised to stick with the more time-consuming natural tests. Even then, CO2SP/EM values can vary considerably depending on whether economic allocation coefficients (Ce) were considered. This approach imposes significant portions of the CO2 emissions of coal-fired electricity production onto fly ash originating from Germany, China, UK, US and Canada. Ce values of ≥0.50% lower the potential CO2SP/EM values up to a point that it seems no longer environmentally worthwhile to aim at high-volume replacement of Portland cement/clinker by fly ash.

scholarly journals Estimation of Carbon Dioxide Emissions from a Traditional Nutrient-Rich Cambodian Diet Food Production System Using Life Cycle Assessment

2021 ◽  
Vol 13 (7) ◽  
pp. 3660
Author(s):  
Rathna Hor ◽  
Phanna Ly ◽  
Agusta Samodra Putra ◽  
Riaru Ishizaki ◽  
Tofael Ahamed ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Co2 Emissions ◽  
Production System ◽  
Agricultural Production ◽  
Carbon Dioxide Emissions ◽  
Food Production ◽  
Carbon Dioxide Co2 ◽  
Food Production System

Traditional Cambodian food has higher nutrient balances and is environmentally sustainable compared to conventional diets. However, there is a lack of knowledge and evidence on nutrient intake and the environmental greenness of traditional food at different age distributions. The relationship between nutritional intake and environmental impact can be evaluated using carbon dioxide (CO2) emissions from agricultural production based on life cycle assessment (LCA). The objective of this study was to estimate the CO2 equivalent (eq) emissions from the traditional Cambodian diet using LCA, starting at each agricultural production phase. A one-year food consumption scenario with the traditional diet was established. Five breakfast (BF1–5) and seven lunch and dinner (LD1–7) food sets were consumed at the same rate and compared using LCA. The results showed that BF1 and LD2 had the lowest and highest emissions (0.3 Mt CO2 eq/yr and 1.2 Mt CO2 eq/yr, respectively). The food calories, minerals, and vitamins met the recommended dietary allowance. The country’s existing food production system generates CO2 emissions of 9.7 Mt CO2 eq/yr, with the proposed system reducing these by 28.9% to 6.9 Mt CO2 eq/yr. The change in each food item could decrease emissions depending on the type and quantity of the food set, especially meat and milk consumption.

scholarly journals Factors Affecting Transport Sector CO2 Emissions in Eastern European Countries: An LMDI Decomposition Analysis

2021 ◽  
Vol 5 (1) ◽  
pp. 25
Author(s):  
Souhir Abbes
Keyword(s):  
Co2 Emissions ◽  
Decomposition Analysis ◽  
European Countries ◽  
Transport Systems ◽  
Transport Sector ◽  
Eastern European ◽  
Factors Affecting ◽  
Mode Of Transport ◽  
Eastern European Countries ◽  
Carbon Dioxide Co2

In this paper, we use the Logarithmic Mean Divisia Index (LMDI) to apply decomposition analysis on Carbon Dioxide (CO2) emissions from transport systems in seven Eastern European countries over the period between 2005 and 2015. The results show that “economic activity” is the main factor responsible for CO2 emissions in all the countries in our sample. The second factor causing increase in CO2 emissions is the “fuel mix” by type and mode of transport. Modal share and energy intensity affect the growth of CO2 emissions but in a less significant way. Finally, only the “population” and “emission coefficient” variables slowed the growth of these emissions in all the countries, except for Slovenia, where the population variable was found to be responsible for the increase in CO2 emissions. These results not only contribute to advancing the existing literature but also provide important policy recommendations.

scholarly journals Analyzing the Renewable Energy and CO2 Emission Levels Nexus at an EU Level: A Panel Data Regression Approach

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 130
Author(s):  
Mihail Busu ◽  
Alexandra Catalina Nedelcu
Keyword(s):  
Renewable Energy ◽  
Panel Data ◽  
Co2 Emissions ◽  
Co2 Emission ◽  
Negative Impact ◽  
National Level ◽  
Renewable Energy Consumption ◽  
Urbanization Level ◽  
Carbon Dioxide Co2 ◽  
The Impact

In the past decades, carbon dioxide (CO2) emissions have become an important issue for many researchers and policy makers. The focus of scientists and experts in the area is mainly on lowering the CO2 emission levels. In this article, panel data is analyzed with an econometric model, to estimate the impact of renewable energy, biofuels, bioenergy efficiency, population, and urbanization level on CO2 emissions in European Union (EU) countries. Our results underline the fact that urbanization level has a negative impact on increasing CO2 emissions, while biofuels, bioenergy production, and renewable energy consumption have positive and direct impacts on reducing CO2 emissions. Moreover, population growth and urbanization level are negatively correlated with CO2 emission levels. The authors’ findings suggest that the public policies at the national level must encourage the consumption of renewable energy and biofuels in the EU, while population and urbanization level should come along with more restrictions on CO2 emissions.

scholarly journals Asymmetric Pd-NHC*-catalyzed coupling reactions

2012 ◽  
Vol 84 (8) ◽  
pp. 1741-1748 ◽  
Author(s):  
E. Peter Kündig ◽  
Yixia Jia ◽  
Dmitry Katayev ◽  
Masafumi Nakanishi
Keyword(s):  
High Temperature ◽  
Coupling Reactions ◽  
Structural Studies ◽  
Methylene Unit ◽  
Asymmetric Coupling ◽  
New Applications ◽  
Very High

Very high asymmetric inductions result in the Pd-catalyzed intramolecular arylation of amides to give 3,3-disubstituted oxindoles when new in situ-generated chiral N-heterocyclic carbene (NHC*) ligands are employed. Structural studies show that conformational locking to minimize allylic strain is the key to understanding the function of these ligands. New applications of these ligands in the frontier area of asymmetric coupling reactions involving C(sp3)–H bonds are detailed. Highly enantioenriched fused indolines are accessible using either preformed- or in situ-generated Pd-NHC* catalysts. Remarkably, this occurs at high temperature (140–160 °C) via excellent asymmetric recognition of an enantiotopic C–H bond in an unactivated methylene unit.

Methane and other Volatile HC Gasses in Produced-Water

2021 ◽  
Author(s):  
Raj Lahoti
Keyword(s):  
Produced Water ◽  
Water Storage ◽  
Laboratory Method ◽  
Storage Tanks ◽  
Condensate Reservoir ◽  
Carbon Dioxide Co2 ◽  
Water Tanks ◽  
Capital Intensive ◽  
Economic Use

Abstract Getting correct estimates for Volatile Organic Compounds (VOCs) and greenhouse gases (GHGs) from water storage tanks is not only important for maintaining emission compliance for state and national regulatory authorities, but also crucial in designing the capital-intensive systems for economic use of methane and other Natural Gas Liquid (NGL) gasses. This paper highlights the significance of gas liberated from produced water tanks in the fields. The paper presents a laboratory method to estimate such emissions from produced-water storage tanks by virtue of the in-situ water getting depressurized and releasing VOCs, and other emission gasses such as Hydrogen Sulfide (H2S) and Carbon Dioxide (CO2). Further, the paper provides qualitative and quantitative assessment of the gas liberated from produced-water by analyzing the gas liberated from produced-water from gas-condensate reservoir wells from the Marcellus region.

scholarly journals Monitoring compliance with sulfur content regulations of shipping fuel by in situ measurements of ship emissions

2015 ◽  
Vol 15 (17) ◽  
pp. 10087-10092 ◽  
Author(s):  
L. Kattner ◽  
B. Mathieu-Üffing ◽  
J. P. Burrows ◽  
A. Richter ◽  
S. Schmolke ◽  
...  
Keyword(s):  
Sulfur Content ◽  
Air Pollutant ◽  
Monitoring Site ◽  
Data Set ◽  
The North ◽  
Position Data ◽  
Gas Measurements ◽  
Set Up ◽  
Carbon Dioxide Co2

Abstract. In 1997 the International Maritime Organisation (IMO) adopted MARPOL Annex VI to prevent air pollution by shipping emissions. It regulates, among other issues, the sulfur content in shipping fuels, which is transformed into the air pollutant sulfur dioxide (SO2) during combustion. Within designated Sulfur Emission Control Areas (SECA), the sulfur content was limited to 1 %, and on 1 January 2015, this limit was further reduced to 0.1 %. Here we present the set-up and measurement results of a permanent ship emission monitoring site near Hamburg harbour in the North Sea SECA. Trace gas measurements are conducted with in situ instruments and a data set from September 2014 to January 2015 is presented. By combining measurements of carbon dioxide (CO2) and SO2 with ship position data, it is possible to deduce the sulfur fuel content of individual ships passing the measurement station, thus facilitating the monitoring of compliance of ships with the IMO regulations. While compliance is almost 100 % for the 2014 data, it decreases only very little in 2015 to 95.4 % despite the much stricter limit. We analysed more than 1400 ship plumes in total and for months with favourable conditions, up to 40 % of all ships entering and leaving Hamburg harbour could be checked for their sulfur fuel content.

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