scholarly journals Influences of CO2 Bubbling Types on Preparation of Calcite Nanoparticles by Carbonation Process

2017 ◽  
Vol 62 (2) ◽  
pp. 209 ◽  
Author(s):  
Mahmut Altiner
Keyword(s):  
Particle Size ◽  
Calcium Hydroxide ◽  
Flow Rate ◽  
Bubble Size ◽  
Flow Rates ◽  
Carbonation Process ◽  
Complete Reaction ◽  
High Production ◽  
Co2 Flow

This study investigates the comparison of influences of CO2 bubbling into the calcium hydroxide (Ca(OH)2) slurry through a microbubble generator (MBG) and an ordinary CO2 generator (OCG) on the preparation of calcite nanoparticles by a carbonation method. Each obtained precipitate was characterized using XRD, SEM and particle size analyses. During the carbonation process at each CO2 flow rates, it was determined that the MBG generates tiny bubbles whereas an increase in CO2 flow rates led to an increase bubble size when the OCG was used. The flow rate of CO2 was not an important parameter with using the MBG as calcite nanoparticles were prepared (<125 nm) at each CO2 flow rates. The necessary time for the complete reaction decreases with an increase in the CO2 flow rates through the MBG in comparison to the OCG. To produce calcite nanoparticles with a high production recovery in shorter times, the MBG should be adopted to the carbonation reactor.

scholarly journals Effects of CO2 Bubble Size, CO2 Flow Rate and Calcium Source on the Size and Specific Surface Area of CaCO3 Particles

Energies ◽  
2015 ◽  
Vol 8 (10) ◽  
pp. 12304-12313 ◽  
Author(s):  
Jun-Hwan Bang ◽  
Kyungsun Song ◽  
Sangwon Park ◽  
Chi Jeon ◽  
Seung-Woo Lee ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Flow Rate ◽  
Bubble Size ◽  
Calcium Source ◽  
Co2 Flow

High Production Rate Synthesis of CdS Nanoparticles Using a Reverse Oscillatory Flow Method

2014 ◽  
Vol 2 (3) ◽  
Author(s):  
Daniel A. Peterson ◽  
C. Padmavathi ◽  
Brian K. Paul
Keyword(s):  
Particle Size ◽  
Production Rate ◽  
Flow Rate ◽  
Oscillatory Flow ◽  
High Flow ◽  
Cds Nanoparticles ◽  
Size Distributions ◽  
High Production Rate ◽  
High Production ◽  
Comparable Size

A reverse oscillatory flow (ROF) mixing system is discussed having a reaction channel 460 μm high by 152 mm wide for high flow rate processing of nanoparticle (NP) chemistries. The ROF system is demonstrated to produce CdS nanoparticles at a production rate of 115.7 g/h with a coefficient of variation (CV) for particle size down to 19%. These production rates are substantially higher than those achieved using other microchannel mixers while maintaining comparable size distributions. Advantages of the ROF approach include the use of larger microchannels which make the reactor easier to fabricate and less vulnerable to clogging.

The Effect of Initial Hydration Temperature on the Characteristics of Calcium Hydroxide and Aragonite Precipitated Calcium Carbonate

2007 ◽  
Vol 124-126 ◽  
pp. 815-818 ◽  
Author(s):  
Ji Whan Ahn ◽  
Jung Ah Kim ◽  
Kwang Suk You ◽  
Hwan Kim ◽  
Hee Chan Cho ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Initial Temperature ◽  
Process Condition ◽  
Hydration Process ◽  
Hydration Time ◽  
Precipitated Calcium Carbonate ◽  
Solid Ratio ◽  
Carbonation Process

Precipitated Calcium Carbonate (PCC) is obtained through three processes; that of calcination, hydration, and carbonation. Thus, changes in each process condition determine the particle size or morphology of the mediums (calcium oxide and calcium hydroxide) as well as the product (PCC). To date, studies concerning precipitated calcium carbonate have mainly focused on the carbonation process, aimed at the manufacturing of PCC. Thus far, few studies on calcination or hydration have been conducted. Calcium hydroxide is regarded as the most important factor during the carbonation process. It is obtained through a hydration process. Therefore, in order to create the valuable PCC studies that center on the hydration process should be carried out. The present study seeks to investigate the effect of the hydration condition, particularly the temperature, on the synthesis characteristics of calcium hydroxide and aragonite PCC. The results show that the particle size of calcium hydroxide changes with variations in the initial hydration temperature. In particular, a higher initial temperature resulted in a larger particle size of the calcium hydroxide used in the synthesis. The particle size and yield of aragonite also increased when calcium hydroxide created at high temperatures was used. However, the water/solid ratio or total amount at the hydration time had no effect on the manufacturing process of aragonite.

Effect of Feed-Flow Rate in a Solid-Liquid Hydrocyclone Based on Total Solid Recovery Equation

2017 ◽  
Vol 751 ◽  
pp. 173-179
Author(s):  
Pichai Soison ◽  
Pakpoom Supachart ◽  
Pratarn Wongsarivej
Keyword(s):  
Particle Size ◽  
Flow Rate ◽  
Concentration Ratio ◽  
Separation Efficiency ◽  
Total Solid ◽  
Feed Flow Rate ◽  
Solid Concentration ◽  
Flow Ratio ◽  
Flow Rates ◽  
Solid Liquid

Many studies of hydrocyclones have confirmed that increasing the feed-flow rate results in a higher separation efficiency. The purpose of this study was to investigate the separation efficiency for a 100 mm solid–liquid hydrocyclone with 1 and 2 wt% solid concentrations at feed-flow rates of 2, 3, 4, 5 and 6 m3/hr. The solid concentration and particle size distribution were analysed using drying–weighing and a particle-size analyser (Mastersizer 2000), respectively. The experimental results indicated that an increase in feed-flow rate from 2 to 4 m3/hr produced decreased separation efficiency. However, when the feed-flow rates increased from 4 to 6 m3/hr, the separation efficiency increased. Furthermore, the higher the feed-flow rate, the smaller the cut size. A novel separation efficiency equation in terms of the concentration ratio and flow ratio is also proposed.

Crystal Growth of Aragonite Precipitated Calcium Carbonate by Seeded Method

2007 ◽  
Vol 544-545 ◽  
pp. 693-696
Author(s):  
Woon Kyoung Park ◽  
Ji Whan Ahn ◽  
Sang Jin Ko ◽  
Choon Han
Keyword(s):  
Crystal Growth ◽  
Calcium Carbonate ◽  
Aspect Ratio ◽  
Reaction Temperature ◽  
Flow Rate ◽  
Gas Flow ◽  
Precipitated Calcium Carbonate ◽  
Co2 Gas ◽  
Carbonation Process ◽  
Co2 Flow

Characteristics of nucleation and crystal growth of aragonite precipitated calcium carbonate in Ca(OH)2 – MgCl2 – CO2 system via a carbonation process is investigated. Aragonite precipitated calcium carbonate with high aspect ratio was synthesized at high reaction temperature and concentration of Ca(OH)2 slurry. The increase in crystal size with decreased in CO2 gas flow rate can be explained by a decrease in the nucleation rate and an increase in the crystal growth rate caused by a decrease in the dissolution rate to CO3 2- ion. In this study, crystal growth of aragonite was investigated by adding aragonite seed. It was found that crystal growth of aragonite precipitated calcium carbonate could be controlled by three-step carbonation process using reactants as the Ca(OH)2. Aragonite with an aspect ratio from 5 to 27 and diameter from 3μm to 24μm was thereby grown at a reaction temperature of 80°C and a CO2 flow rate of 50ml/min. It was also found that MgCl2 aqueous solution can be used again in the carbonation process for the synthesis of aragonite precipitated calcium carbonate.

scholarly journals Effect of the Flow Rate on the Relative Permeability Curve in the CO2 and Brine System for CO2 Sequestration

2021 ◽  
Vol 13 (3) ◽  
pp. 1543
Author(s):  
Gu Sun Jeong ◽  
Seil Ki ◽  
Dae Sung Lee ◽  
Ilsik Jang
Keyword(s):  
Relative Permeability ◽  
Flow Rate ◽  
Flow Behavior ◽  
Co2 Injection ◽  
Displacement Efficiency ◽  
Two Phase ◽  
Flow Rates ◽  
Injection Flow ◽  
Wide Range ◽  
Co2 Flow

The relative permeabilities of CO2 and brine are important parameters that account for two-phase flow behavior, CO2 saturation distribution, and injectivity. CO2/brine relative permeability curves from the literature show low endpoint CO2 permeability values and high residual brine saturation values. These are the most distinguishing aspects of the CO2/brine relative permeability from oil/water and gas/oil. In this study, this aspect is investigated experimentally by employing a wide range of CO2 injection flow rates. As a result, all the measurements align with previous studies, having low endpoint relative permeability and high residual brine saturation values. They have obvious relationships with the changes in CO2 flow rates. As the CO2 flow rate increases, the endpoint relative permeability increases, the residual brine saturation decreases, and they converge to specific values. These imply that a high CO2 injection flow rate results in high displacement efficiency, but the improvement in efficiency decreases as the flow rate increases. The reasons are identified with the concept of the viscous and capillary forces, and their significance in the CO2 injection into a reservoir is analyzed.

Effect of CO2 Flow Rate on the Synthesis Nanosized Precipitated Calcium Carbonate, PCC

2013 ◽  
Vol 481 ◽  
pp. 72-75
Author(s):  
O. Nooririnah ◽  
Azwar Azhari Muhamad ◽  
Y. Yusliza ◽  
Abreeza Manap ◽  
M.J. Md Ashadi
Keyword(s):  
Particle Size ◽  
Wastewater Treatment ◽  
Calcium Carbonate ◽  
Ionic Strength ◽  
Calcium Hydroxide ◽  
Flow Rate ◽  
High Purity ◽  
Precipitated Calcium Carbonate ◽  
Particle Size And Shape ◽  
Spraying Method

The precipitated of calcium carbonate has attractedmuch attention because of its numerous applications in various areas of plastics, textiles, rubbers, adhesives, paints and wastewater treatment. Nanosized of precipitated calcium carbonate,(PCC) will enhance the properties and give better performance. Its high purity and close controlled particle size and shape are making it the white filler of choice. Nanosized precipitated calcium carbonate particles were prepared using spraying method. The particles were prepared using three (3) different concentrations of Calcium Hydroxide,Ca (OH)2, three (3) CO2flow rate and three (3) different calcinations temperature. The three (3) concentration of Calcium Hydroxide that been used are 25g/200ml, 25g/ 400ml and 25g/800ml and each of these initial solution sprayed at three (3) different CO2flow rate, 5l/per-minute, 7l/per-minute and 10l/per-minute. Calcium Carbonate, CaCO3powders were then calcined at three (3) different temperature, 1100°C,1200°C and 1300°C. Images from SEM showed morphology of the particles changed to spindle-like or prismatic when the ionic strength of the Calcium Hydroxide, Ca (OH)2was increased.

High Production Rate Synthesis of CdS Nanoparticles Using a Reverse Oscillatory Flow Method

2014 ◽  
Author(s):  
Daniel A. Peterson ◽  
C. Padmavathi ◽  
Brian K. Paul
Keyword(s):  
Particle Size ◽  
Production Rate ◽  
Flow Rate ◽  
Oscillatory Flow ◽  
High Flow ◽  
Cds Nanoparticles ◽  
Size Distributions ◽  
High Production Rate ◽  
High Production ◽  
Comparable Size

A reverse oscillatory flow (ROF) mixing system is discussed having a reaction channel 460 μm high by 152 mm wide for high flow rate processing of nanoparticle chemistries. The ROF system is demonstrated to produce CdS nanoparticles at a production rate of 115.7 g/hour with a coefficient of variation for particle size down to 19%. These production rates are substantially higher than those achieved using other microchannel mixers while maintaining comparable size distributions. Advantages of the ROF approach include the use of larger microchannels which make the reactor easier to fabricate and less vulnerable to clogging.

Effect of Flow Rate and Particle Size on Heat Transfer to Dense Granular Flows

2016 ◽  
Author(s):  
Megan F. Watkins ◽  
Richard D. Gould
Keyword(s):  
Heat Transfer ◽  
Particle Size ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flow Rate ◽  
Granular Flows ◽  
Heat Transfer Fluid ◽  
Storage Medium ◽  
Flow Rates ◽  
Dense Granular Flows

The increasing demand for renewable energy sources necessitates the development of more efficient technologies. Concentrated solar power (CSP) towers exhibit promising qualities, as temperatures greater than 1000°C are possible. The heat transfer fluid implemented to capture the sun’s energy significantly impacts the overall performance of a CSP system. Current fluids, such as molten nitrate salts and steam, have limitations; molten salts are limited by their small operational temperature range while steam requires high pressures and is unable to act as an effective storage medium. As a result, a new heat transfer fluid composed of ceramic particles is being investigated, as ceramic particles demonstrate no practical limit on operation temperature and have the ability to act as a storage medium. This study sought to further investigate the use of dense granular flows as a new heat transfer fluid. Previous work validated the use of such flows as a heat transfer fluid; the present work examined the effect of flow rate, as well as the particle size and type on the heat transfer to the particle fluid. Three different types of particles were tested, along with two different diameter particles. Of the three materials tested, the particle type did not appear to effect the heat transfer. Particle diameter, however, did effect the heat transfer, as a smaller diameter particle yielded slightly higher heat transfer to the fluid. Flow rates ranging from 30 to 200 kg/m2-s were tested. Initially, the heat transfer to the flow, characterized by the convective heat transfer coefficient, decreased with increasing flow rate. However, at approximately 80 kg/m2-s, the heat transfer coefficient began to increase with increasing flow rate. These results indicate that a dense granular flow consisting of small diameter particles and traveling at very slow or fast flow rates yields the best wall to “fluid” heat transfer.

Pyrolysis of brown algae (Bifurcaria Bifurcata) in a stainless steel tubular reactor: From a review to a case study

2018 ◽  
Vol 14 (1) ◽  
pp. 31-60 ◽  
Author(s):  
M. Y. Guida ◽  
F. E. Laghchioua ◽  
A. Hannioui
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Flow Rate ◽  
Brown Algae ◽  
Tubular Reactor ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Bifurcaria Bifurcata ◽  
Bio Oil

This article deals with fast pyrolysis of brown algae, such as Bifurcaria Bifurcata at the range of temperature 300–800 °C in a stainless steel tubular reactor. After a literature review on algae and its importance in renewable sector, a case study was done on pyrolysis of brown algae especially, Bifurcaria Bifurcata. The aim was to experimentally investigate how the temperature, the particle size, the nitrogen flow rate (N2) and the heating rate affect bio-oil, bio-char and gaseous products. These parameters were varied in the ranges of 5–50 °C/min, below 0.2–1 mm and 20–200 mL. min–1, respectively. The maximum bio-oil yield of 41.3wt% was obtained at a pyrolysis temperature of 600 °C, particle size between 0.2–0.5 mm, nitrogen flow rate (N2) of 100 mL. min–1 and heating rate of 5 °C/min. Liquid product obtained under the most suitable and optimal condition was characterized by elemental analysis, 1H-NMR, FT-IR and GC-MS. The analysis of bio-oil showed that bio-oil from Bifurcaria Bifurcata could be a potential source of renewable fuel production and value added chemicals.

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