Utilization of Mineral Sequestration for CO2 Capturing in Car Parks and Tunnels

2020 ◽  
Vol 38 (5A) ◽  
pp. 728-737
Author(s):  
Aymen J. Alsaad ◽  
Tareq S. Al-Attar ◽  
Basil S. Al-Shathr
Keyword(s):  
Calcium Carbonate ◽  
Co2 Concentration ◽  
Pervious Concrete ◽  
Co2 Uptake ◽  
Water Tank ◽  
Vehicle Exhaust ◽  
Carbonation Depth ◽  
Mineral Sequestration ◽  
Co2 Capturing ◽  
Work Goals

Decreasing the emissions of CO2 that come from vehicle exhaust, especially in car parking and tunnels, is so vital. CO2 emissions cause corrosion to a reinforcement of concrete. Thus, there is a need to provide a layer that protects the reinforcement from the reach of this harmful gas. This work goals to investigate the efficiency of using board units from Pozzolime concrete and pervious concrete to sequestrate CO2 from the environment and then to convert it into calcium carbonate inside the concrete. The units have dimensions of (200×400×40±5). All specimens were cured in a water tank after about 48 hours after casting. Then paint the sample from all surfaces (three layers) excluding the top surface. The pervious concrete and Pozzolime specimens, at age of 28 days, were put in the chamber, then the gas was supplied to the chamber with concentrations of 15%, 25%, and 50 %, for 24 hours. The efficiency was evaluated through carbonation depth, CO2-uptake, and weight change. The results showed that the maximum CO2 uptake was recorded at the age of 28 days for Pozzolime concrete when exposed to 50% of CO2 concentration.

scholarly journals Utilization of Pervious Concrete in CO2 Capturing to Control Environmental Impact of Portland Cement

2018 ◽  
Vol 7 (4.20) ◽  
pp. 382 ◽  
Author(s):  
Aymen J. Alsaad ◽  
Tareq S.al-Attar ◽  
Basil S. Alshathr
Keyword(s):  
Compressive Strength ◽  
Calcium Carbonate ◽  
Environmental Impact ◽  
Portland Cement ◽  
Weight Change ◽  
Cement Industry ◽  
Pervious Concrete ◽  
Co2 Uptake ◽  
Co2 Capturing ◽  
Main Producer

The cement industry is a main producer of greenhouse gases that is responsible for 5–7% of CO2 emissions. Therefore, it is important to find a method to reduce the concentration of this gas in the environment especially in places such as tunnels. This work aims to use pervious concrete to capture CO2 from the environment and transform it to calcium carbonate inside its matrix. The pervious concrete exposed at 7, 14, and 28 days age to 25 and 50% concentration of CO2 for a period of 2 and 4 hours to study the extent of carbonation inside this concrete. In addition to that, the effects of carbonation on compressive strength, weight change, CO2-uptake and change in permeability were studied. The results showed that higher concentration of CO2 and longer exposure periods caused deeper penetration of carbonation. The maximum recorded CO2 uptake by pervious concrete occurs when it was exposed to higher CO2 % and longer duration of exposure at the age of 7 days.   

scholarly journals Effects of Environmental Factors on Concrete Carbonation Depth and Compressive Strength

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2167 ◽  
Author(s):  
Ying Chen ◽  
Peng Liu ◽  
Zhiwu Yu
Keyword(s):  
Compressive Strength ◽  
Phase Composition ◽  
Relative Humidity ◽  
Co2 Concentration ◽  
Crystal Structure Analysis ◽  
Hydration Products ◽  
Carbonation Depth ◽  
Concrete Carbonation ◽  
Before And After ◽  
Compressive Strength Of Concrete

The influence of temperature, CO2 concentration and relative humidity on the carbonation depth and compressive strength of concrete was investigated. Meanwhile, phase composition, types of hydration products and microstructure characteristics of samples before and after the carbonation were analyzed by XRD and ESEM. Research results demonstrate that temperature, CO2 concentration and relative humidity influence the carbonation depth and compressive strength of concrete significantly. There is a linear relationship between temperature and carbonation depth, as well as the compressive strength of concrete. CO2 concentration and relative humidity present a power function and a polynomial function with carbonation depth of concrete, respectively. The concrete carbonation depth increases with the increase of relative humidity and reaches the maximum value when the relative humidity is 70%. Significant differences of phase composition, hydration products and microstructure are observed before and after the carbonation. Carbonization products of samples are different with changes of temperatures (10 °C, 20 °C and 30 °C). The result of crystal structure analysis indicates that the carbonation products are mainly polyhedral spherical vaterite and aragonite.

scholarly journals Immobilized Microalgae-Based Photobioreactor for CO2 Capture (IMC-CO2PBR): Efficiency Estimation, Technological Parameters, and Prototype Concept

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1031
Author(s):  
Marcin Dębowski ◽  
Mirosław Krzemieniewski ◽  
Marcin Zieliński ◽  
Joanna Kazimierowicz
Keyword(s):  
Carbon Dioxide Emissions ◽  
Functional Model ◽  
Biomass Concentration ◽  
Co2 Concentration ◽  
Ambient Air ◽  
Co2 Uptake ◽  
Co2 Removal ◽  
Exhaust Gas ◽  
Technological Parameters ◽  
Efficiency Estimation

Microalgae-mediated CO2 sequestration has been a subject of numerous research works and has become one of the most promising strategies to mitigate carbon dioxide emissions. However, feeding flue and exhaust gas into algae-based systems has been shown to destroy chloroplasts, as well as disrupt photosynthesis and other metabolic processes in microalgae, which directly limits CO2 uptake. CO2 biosequestration in existing photobioreactors (PBRs) is also limited by the low biomass concentration in the growth medium. Therefore, there is a real need to seek alternative solutions that would be competitive in terms of performance and cost-effectiveness. The present paper reports the results of experiments aimed to develop an innovative trickle bed reactor that uses immobilized algae to capture CO2 from flue and exhaust gas (IMC-CO2PBR). In the experiment, ambient air enriched with technical-grade CO2 to a CO2 concentration of 25% v/v was used. The microalgae immobilization technology employed in the experiment produced biomass yields approximating 100 g DM/dm3. A relationship was found between CO2 removal rates and gas volume flux: almost 40% of CO2 was removed at a feed of 25 dm3 of gas per hour, whereas in the 200 dm3/h group, the removal efficiency amounted to 5.9%. The work includes a determination of basic process parameters, presentation of a developed functional model and optimized lighting system, proposals for components to be used in the system, and recommendations for an automation and control system for a full-scale implementation.

scholarly journals Effect of Graphene Nanoplatelet on the Carbonation Depth of Concrete under Changing Climate Conditions

2021 ◽  
Vol 11 (19) ◽  
pp. 9265
Author(s):  
Yingzi Zhang ◽  
Yanze Wang ◽  
Mingqian Yang ◽  
Huatao Wang ◽  
Guofang Chen ◽  
...  
Keyword(s):  
Control Sample ◽  
Co2 Concentration ◽  
Favorable Effect ◽  
Carbonation Depth ◽  
Graphene Nanoplatelet ◽  
Carbonation Reaction ◽  
Climate Conditions ◽  
Ordinary Concrete ◽  
Changing Climate ◽  
Carbon Dioxide Co2

Climate change has been unprecedented in the past decades or even thousands of years, which has had an adverse impact on the mechanical properties of concrete structures. Many researchers have begun to study new concrete materials. Graphene nanoplatelet (GNP) is an attractive nanomaterial that can change the crystal structure of concrete and improve durability. The aim of the present study was to investigate the effect of GNP (0.05%wt) on the carbonation depth of concrete under simulated changing climate conditions (varying temperature, relative humidity, and carbon dioxide (CO2) concentration), and compare it with ordinary concrete. When the concentration of CO2 is variable, the carbonation depth of graphene concrete is 10% to 20% lower than that of ordinary concrete. When the temperature is lower than 33 °C, the carbonation depth of graphene concrete is less than that of the control sample; however, above 33 °C, the thermal conductivity of GNP increases the carbonation reaction rate of concrete. When the humidity is a variable, the carbonation depth of graphene concrete is less than 15% to 30% of ordinary concrete, and when the humidity is higher than 78%, the difference in the carbonation depth between the ordinary concrete and the graphene concrete decreases gradually. The overall results indicated that GNP has a favorable effect on anti-carbonation performance under changing climate conditions.

Assimilate Source-Sink Relationships in Capsicum annuum L. III. The Effects of Fruit Excision on Photosynthesis and Leaf and Stem Carbohydrates.

1978 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
AJ Hall ◽  
FL Milthorpe
Keyword(s):  
Control Mechanism ◽  
Dark Respiration ◽  
Soluble Sugars ◽  
Co2 Concentration ◽  
Co2 Uptake ◽  
Factors Affecting ◽  
Co2 Compensation Point ◽  
Time Period ◽  
Internal Co2 ◽  
Source Sink

Removal of the rapidly growing fruit from a Capsicum plant reduced the rate of net CO2 uptake by its leaves by up to 30% during the time period explored (0.5 - 7 days). This reduction was associated with increases in both the leaf (to about 200%) and intracellular (to about 30%) resistances, these changes having about equal effects on reducing the rate of CO2 uptake. Changes in photorespiration, dark respiration and CO2 compensation point were very small. The rate of CO2 uptake and the associated resistances were also changed by modifying the light regime and other factors affecting the source-sink balance. Changes in the leaf resistance were not attributable to variations in the internal CO2 concentration or in the water economy of the leaf; its control mechanism remains unexplained. The concentration of soluble sugars in the source leaf was completely unaffected but that of polysaccharides was changed by defruiting and by 50% defoliation. However, variations in the intracellular resistance were not closely related to these changes and there is yet no evidence of the nature of its control mechanism. Changes in both soluble sugars and polysaccharides in the stem were more pronounced than in the leaves.

scholarly journals Quantitative Analysis of CO2 Uptake and Mechanical Properties of Air Lime-Based Materials

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2903 ◽  
Author(s):  
Sung-Hoon Kang ◽  
Yang-Hee Kwon ◽  
Juhyuk Moon
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Co2 Concentration ◽  
Hydrated Lime ◽  
Cement Industry ◽  
Raw Material ◽  
Co2 Uptake ◽  
Carbonation Reaction ◽  
Lime Mortar ◽  
Curing Conditions

In the cement industry, utilization of a sustainable binder that has a lower energy consumption and carbon dioxide (CO2) emission than Portland cement is becoming increasingly important. Air lime is a binder that hardens by absorbing CO2 from the atmosphere, and its raw material, hydrated lime, is manufactured at a lower temperature (around 900 °C) than cement (around 1450 °C). In this study, the amount and rate of CO2 uptake by air lime-based materials are quantitatively evaluated under ambient curing conditions of 20 °C, 60% relative humidity, and 0.04% CO2 concentration. In addition, the effects of the water-to-binder ratio (w/b) and silica fume addition on the material properties of the air lime mortar, such as strength, weight change, carbonation depth, and pore structure, are investigated. Unlike hydraulic materials, such as Portland cement, the air lime mortar did not set and harden under a sealed curing condition, however, once exposed to dry air, the mortar began to harden by absorbing CO2. During the first week, most of the internal water evaporated, thus, the mortar weight was greatly reduced. After that, however, both the weight and the compressive strength consistently increased for at least 180 days due to the carbonation reaction. Based on the 91-day properties, replacing 10% of hydrated lime with silica fume improved the compressive and flexural strengths by 27% and 13% respectively, whereas increasing the w/b from 0.4 to 0.6 decreased both strengths by 29% due to the increased volume of the capillary pores. The addition of silica fume and the change in the w/b had no significant impact on the amount of CO2 uptake, but these two factors were effective in accelerating the CO2 uptake rate before 28 days. Lastly, the air lime-based material was evaluated to be capable of recovering half of the emitted CO2 during the manufacture of hydrated lime within 3 months.

scholarly journals Optimal Mixture Design of Low-CO2 High-Volume Slag Concrete Considering Climate Change and CO2 Uptake

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Han-Seung Lee ◽  
Seung-Min Lim ◽  
Xiao-Yong Wang
Keyword(s):  
Climate Change ◽  
Design Method ◽  
High Strength ◽  
High Volume ◽  
Mixture Design ◽  
Control Factor ◽  
Co2 Uptake ◽  
Uptake Ratio ◽  
Carbonation Depth ◽  
Low Co2

Abstract High-volume slag (HVS) can reduce the CO2 emissions of concrete, but increase the carbonation depth of concrete. In particular, because of the effects of climate change, carbonation will accelerate. However, the uptake of CO2 as a result of carbonation can mitigate the harm of CO2 emissions. This study proposes an optimal mixture design method of low-CO2 HVS concrete considering climate change, carbonation, and CO2 uptake. Firstly, net CO2 emissions are calculated by subtracting the CO2 emitted by the material from the uptake of CO2 by carbonation. The strength and depth of carbonation are evaluated by a comprehensive model based on hydration. Secondly, a genetic algorithm (GA) is used to find the optimal mixture. The objective function of the GA is net CO2 emissions. The constraints of the GA include the strength, carbonation, workability, and range of concrete components. Thirdly, the results show that carbonation durability is a control factor of the mixture design of low-strength HVS concrete, while strength is a control factor of the mixture design of high-strength HVS concrete. After considering climate change, the threshold of strength control increases. With the increase of strength, the net CO2 emissions increase, while the CO2 uptake ratio decreases.

scholarly journals Quantification of ikaite in Antarctic sea ice

2012 ◽  
Vol 6 (1) ◽  
pp. 505-530 ◽  
Author(s):  
M. Fischer ◽  
D. N. Thomas ◽  
A. Krell ◽  
G. Nehrke ◽  
J. Göttlicher ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Sea Ice ◽  
Temporal Distribution ◽  
Ice Cores ◽  
Horizontal Distribution ◽  
Total Alkalinity ◽  
Co2 Uptake ◽  
Calcium Carbonate Precipitation ◽  
Antarctic Sea Ice ◽  
Polar Oceans

Abstract. Calcium carbonate precipitation in sea ice can increase pCO2 during precipitation in winter and decrease pCO2 during dissolution in spring. CaCO3 precipitation in sea ice is thought to potentially drive significant CO2 uptake by the ocean. However, little is known about the quantitative spatial and temporal distribution of CaCO3 within sea ice. This is the first quantitative study of hydrous calcium carbonate, as ikaite, in sea ice and discusses its potential significance for the carbon cycle in polar oceans. Ice cores and brine samples were collected from pack and land fast sea ice between September and December 2007 during an expedition in the East Antarctic and another off Terre Adélie, Antarctica. Samples were analysed for CaCO3, Salinity, DOC, DON, Phosphate, and total alkalinity. A relationship between the measured parameters and CaCO3 precipitation could not be observed. We found calcium carbonate, as ikaite, mostly in the top layer of sea ice with values up to 126 mg ikaite per liter melted sea ice. This potentially represents a contribution between 0.12 and 9 Tg C to the annual carbon flux in polar oceans. The horizontal distribution of ikaite in sea ice was heterogenous. We also found the precipitate in the snow on top of the sea ice.

scholarly journals Calcium carbonate corrosivity in an Alaskan inland sea

2014 ◽  
Vol 11 (2) ◽  
pp. 365-379 ◽  
Author(s):  
W. Evans ◽  
J. T. Mathis ◽  
J. N. Cross
Keyword(s):  
Calcium Carbonate ◽  
Focal Point ◽  
Point Sources ◽  
Atmospheric Co2 ◽  
Co2 Uptake ◽  
Mode Water ◽  
Tidewater Glaciers ◽  
South Central ◽  
System Data ◽  
Shell Forming

Abstract. Ocean acidification is the hydrogen ion increase caused by the oceanic uptake of anthropogenic CO2, and is a focal point in marine biogeochemistry, in part, because this chemical reaction reduces calcium carbonate (CaCO3) saturation states (Ω) to levels that are corrosive (i.e., Ω ≤ 1) to shell-forming marine organisms. However, other processes can drive CaCO3 corrosivity; specifically, the addition of tidewater glacial melt. Carbonate system data collected in May and September from 2009 through 2012 in Prince William Sound (PWS), a semienclosed inland sea located on the south-central coast of Alaska and ringed with fjords containing tidewater glaciers, reveal the unique impact of glacial melt on CaCO3 corrosivity. Initial limited sampling was expanded in September 2011 to span large portions of the western and central sound, and included two fjords proximal to tidewater glaciers: Icy Bay and Columbia Bay. The observed conditions in these fjords affected CaCO3 corrosivity in the upper water column (< 50 m) in PWS in two ways: (1) as spring-time formation sites of mode water with near-corrosive Ω levels seen below the mixed layer over a portion of the sound, and (2) as point sources for surface plumes of glacial melt with corrosive Ω levels (Ω for aragonite and calcite down to 0.60 and 1.02, respectively) and carbon dioxide partial pressures (pCO2) well below atmospheric levels. CaCO3 corrosivity in glacial melt plumes is poorly reflected by pCO2 or pHT, indicating that either one of these carbonate parameters alone would fail to track Ω in PWS. The unique Ω and pCO2 conditions in the glacial melt plumes enhances atmospheric CO2 uptake, which, if not offset by mixing or primary productivity, would rapidly exacerbate CaCO3 corrosivity in a positive feedback. The cumulative effects of glacial melt and air–sea gas exchange are likely responsible for the seasonal reduction of Ω in PWS, making PWS highly sensitive to increasing atmospheric CO2 and amplified CaCO3 corrosivity.

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