scholarly journals Bubble column application on purification of biogas and production of nano-calcium carbonate in continuous process

2020 ◽  
Vol 16 (3) ◽  
pp. 286-291
Author(s):  
Yukh Ihsana ◽  
Putu Adhi Rama ◽  
Sugeng Winardi ◽  
Tantular Nurtono
Keyword(s):  
Calcium Carbonate ◽  
Flow Rate ◽  
Gas Flow ◽  
Bubble Column ◽  
Continuous Process ◽  
Calorific Value ◽  
Co2 Concentration ◽  
Absorption Process ◽  
Gas Flow Rate ◽  
Precipitated Calcium Carbonate

Purification of biogas by removing carbon dioxide content has been developed to increase its calorific value. The CO2  contained in biogas was absorbed by contacting Ca(OH)2 solution and CO2 in the bubble column to produce high purity of biogas and generated precipitated calcium carbonate (PCC) simultaneously. Two sources of CO2 were used in this work, which were CO2 contained in biogas and pure CO2. Pure CO2 was used as a benchmark in this study to show the effect of the presence of methane contained in biogas on the absorption process. The investigation was done in a continuous process. The results showed that the highest absorption of CO2 was obtained in biogas at 79.34 %. PCC with calcite phases was successfully formed in 225–270 nm. Rhombohedral calcite phase was formed by the use of pure CO2 and biogas as a source of CO2. The use of CO2 contained in biogas and pure CO2 in the absorption process did not have an effect on the crystalline phase and morphology of calcite formed. Several factors that significantly affected the absorption of CO2 were gas flow rate, absorbent flow rate, CO2 concentration in the gas inlet, and the initial liquid level in the bubble column. 

Roles of Additives on Crystal Growth Rate of Precipitated Calcium Carbonate

2007 ◽  
Vol 124-126 ◽  
pp. 707-710 ◽  
Author(s):  
Ji Whan Ahn ◽  
Woon Kyoung Park ◽  
Kwang Suk You ◽  
Hee Chan Cho ◽  
Sang Jin Ko ◽  
...  
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Calcium Carbonate ◽  
Flow Rate ◽  
Nucleation Rate ◽  
Gas Flow ◽  
Crystal Growth Rate ◽  
Gas Flow Rate ◽  
Precipitated Calcium Carbonate ◽  
Co2 Gas

The characteristics of nucleation and the crystal growth of aragonite-precipitated calcium carbonate in Ca(OH)2 – MgCl2 – CO2 system by a carbonation process is investigated. MgCl2, in this study, was added in order to increase the formation yield of aragonite precipitated calcium carbonate. Optimum conditions of the concentration of the reactants, the temperature and the amount of additives were studied. The formation yield of calcite gradually decreased, and the formation yield of aragonite increased with the addition of MgCl2. A higher formation yield of above 98% for aragonite is obtained by the adding of the Mg2+ ion in a 0.2M Ca(OH)2 – 0.6M MgCl2 – CO2 system at 80. The nucleation rate increased as the temperature decreased and as the CO2 gas flow rate increased. The particle size and aspect ratio increased at a high temperature, a low flow rate of gas, and a high concentration of Ca(OH)2 slurry. Small-sized aragonite was obtained at a low temperature. The increase in crystal size with the decrease in the CO2 gas flow rate can be explained by the decrease in the nucleation rate, in addition to the increase in the crystal growth rate resulting from the decrease in the dissolution rate to CO3 2- ion.

Influence Parameters in the Ozonation of Clofibric Acid Using a Cascade Bubble Column

2012 ◽  
Vol 573-574 ◽  
pp. 538-541
Author(s):  
Yan Ping Duan ◽  
Sven Geissen ◽  
Ling Chen
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Bubble Column ◽  
Continuous Operation ◽  
Clofibric Acid ◽  
Gas Flow Rate ◽  
Toc Removal ◽  
Operation Parameters

Ozonation of clofibric acid (CA) in aqueous solution was carried out under continuous operation in a cascade bubble column. The influence of operation parameters including initial CA concentration, gas flow rate, liquid flow rate and pH on the removal of CA and TOC was investigated. The results indicated that ozonation could be used to effectively remove CA from water. Increasing the initial CA concentration resulted in a decrease of the CA and TOC removal efficiency. A comparison of CA removal efficiency and ozone utilization between cascade and conventional bubble column indicated that cascade bubble column was an effective way for increasing the solubility ozone in the reactor.

Nonlinear Bubbling Hydrodynamics in a Gas-Liquid Bubble Column with a Single Nozzle

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Mingyan Liu
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Chaotic Behavior ◽  
Bubble Column ◽  
Pressure Fluctuations ◽  
Time Signal ◽  
Kolmogorov Entropy ◽  
Gas Flow Rate ◽  
Non Linear ◽  
Liquid Bubble

In this work, the chaotic bubbling mechanism in a gas-liquid bubble column with a single nozzle was investigated. The signal for the analysis was the time series of pressure fluctuations measured from a pressure transducer probe placed in the bubble column close to the nozzle. In order to study the bubbling process, statistical analysis, qualitative and quantitative non-linear analyses were carried out for the pressure fluctuations. Power spectra used as standard statistical measures provided preliminary evidence that bubbling in the middle values of gas flow rates may be chaotic in nature. Phase plots provided a qualitative means of analyzing the fine geometry structure of the attractor reconstructed from the bubbling time signal. Positive finite estimates of the Kolmogorov entropy provided a quantitative evidence of behavior consistent with chaos. Besides previous diagnostic tools, the local non-linear short-term prediction was also used as a supplement method. It was found that the bubbling process exhibits a deterministic chaotic behavior in a certain range of the gas flow rate. When increasing the gas flow rate, the sequence of periodic bubbling, primary and advanced chaotic bubbling, and jetting or random bubbling were successively observed. However, no clear period doubling sequence leading to chaotic behavior was observed. The sharp loss of the ability to predict the pressure signal successfully with the non-linear prediction method provides a strongest evidence of the presence of the chaotic bubbling. The variations of the non-linear invariants, such as the Kolmogorov entropy and the correlation dimension together with the plot of the correlation integral with the operation conditions, might be developed as potential and effective quantitative tools for flow regime identification of the bubbling process.

Absorption and Mass Transfer of CO2 in Monoethanolamine Solution

2016 ◽  
Vol 859 ◽  
pp. 153-157
Author(s):  
Pao Chi Chen ◽  
Sheng Zhong Lin
Keyword(s):  
Mass Transfer ◽  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Bubble Column ◽  
Operating Conditions ◽  
Gas Flow Rate ◽  
Constant Ph ◽  
Gas Liquid Flow

This work uses a continuous bubble-column scrubber for the absorption of CO2 with a 5M MEA solution under a constant pH environment to explore the effect of the pH of the solution and gas-flow rate (Qg) on the removal efficiency (E), absorption rate (RA), overall mass-transfer coefficient (KGa), liquid flow rate (QL), gas-liquid flow ratio (γ), and scrubbing factors (φ). From the outlet CO2 concentration with a two-film model, E, RA, KGa, QL, γ, and φ can be simultaneously determined at the steady state. Depending on the operating conditions, the results show that E (80-97%), RA(2.91x10-4-10.0x10-4mol/s-L), KGa (0.09-0.48 1/s), QL(8.74-230.8mL/min), γ (0.19-5.39), and φ (0.031-0.74 mol/mol-L) are found to be comparable with other solvents. In addition, RA, KGa, E, and QL have been used to correlate with pH and Qg, respectively, with the results further explained.

scholarly journals Mass Transfer Coefficient of Ozone in a Bubble Column

2018 ◽  
Vol 156 ◽  
pp. 02015 ◽  
Author(s):  
Ratnawati Ratnawati ◽  
Dyah Arum Kusumaningtyas ◽  
Purbo Suseno ◽  
Aji Prasetyaningrum
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Gas Flow ◽  
Bubble Column ◽  
Bubble Column Reactor ◽  
Ozone Generator ◽  
Gas Flow Rate ◽  
State Concentration

The effect of flow rate of ozone-containing gas and pH on the mass transfer coefficient of ozone through water in a bubble column reactor has been studied. Ozone was generated from air using a corona discharge ozone generator. The flow rate of air was varied from 2 to 5 L min-1, while pH was varied from 4 to 10. The gas containing ozone was bubbled to the reactor containing 1.5 L of 2% KI solution. The temperature was set at 28±1ºC. The concentration of ozone was determined using titrimetric method every 5 minutes. The results show that the concentration of ozone increases with time, and it reaches a steady-state concentration after 30 minutes of ozonation. The gas flow rate and pH apparently affect both the concentration and the kLa. The highest kLa of 2.1 X 10-2 s-1 is obtained at pH 4 with a gas flow rate of 4 L min-1.

scholarly journals CO2 Capture in A Bubble-Column Scrubber Using MEA/CaCl2/H2O Solution—Absorption and Precipitation

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 694
Author(s):  
Pao Chi Chen ◽  
Shiun Huang Zhuo
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Ph Value ◽  
Bubble Column ◽  
Operating Conditions ◽  
Co2 Absorption ◽  
Gas Flow Rate ◽  
Gas Concentration ◽  
Ph Values

This study used the solvent monoethylamine (MEA)/CaCl2/H2O to investigate CO2 absorption and CaCO3 crystallization in a bubble column scrubber. The variables explored were pH, gas flow rate, gas concentration, the liquid flow rate of the solution to absorb CO2, and CaCO3 crystallization. Under a continuous mode, the solution of CaCl2 was fed continuously, and the pH dropped after CO2 absorption. To maintain the set pH value, there was an automatic input of the MEA solvent into the bubble column. In addition to maintaining the pH, the solution could also absorb CO2 and produce CaCO3 crystals, which served two purposes. The results showed that there were mainly vaterite crystals. At different pH values, the lower the pH, the higher the precipitation rate of vaterite (Fp), and vice versa. However, under different gas flow rates, the Fp decreased as the pH value increased. Additionally, the process variables also affected the absorption rate (RA) and the overall mass-transfer coefficient (KGa) generally increased with increasing pH, gas concentration, and gas flow rate. However, it slowed down under operating conditions at high pH and high gas flow rate. Finally, correlation equations for RA, KGa, and Fp were also obtained and discussed in the study.

scholarly journals Effect Of Sparging In Microalgae (Dunaliella Tertiolecta) Cuture Using Bubble Column

REAKTOR ◽  
2017 ◽  
Vol 6 (2) ◽  
pp. 56
Author(s):  
Hadiyanto Hadiyanto ◽  
M. Barbosa ◽  
R. Wijffels
Keyword(s):  
Cell Death ◽  
Rate Constant ◽  
Flow Rate ◽  
Death Rate ◽  
Gas Flow ◽  
Bubble Column ◽  
Animal Cell ◽  
Gas Flow Rate ◽  
Cell Death Rate ◽  
Entrance Velocity

Microalgae as a photosynthetic microorganism that contain chlorophyll has high potential to produce novel high value compounds that can be used in food, pharmaceutical and cosmetic industries. With lack of rigid cell wall, microalgae susceptible to have  hydrodynamic stress by increasing aeration rate. Increasing gas flow rate will increase the productivity to optimum condition, but after this condition the productivity will  decrease due to cell disruption. In this research has been  focused on effect of sparging on  microalgae cell damage. Sparging experiment was carried out by varying gas flow rate between 0.59 to 5.13 L.min-1 with a sparger made from needle inserted to a piece of silicon. The needle was used with diameter 0.4 to 1.2 mm and 1-9 needles. With this variables resulted gas entrance velocity between 2.56-104 m.s-1. The cell death rate constant (kd) was calculated by loss of cell viability in time using Coulter counter and Flowcytometer. From the experiments resulted gas entrance velocity was main cause for cell damagae. The small bubble was more detrimental than bigger size of bubble. Bubble rising as like in animal cell culture was no effect to detrimental cell.Keywords : D. tertiolecta, cell death rate constant, gas entrance velocity

scholarly journals Biofiksasi CO2 Oleh Mikroalga Chlamydomonas sp dalam Photobioreaktor Tubular

REAKTOR ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 37
Author(s):  
Hadiyanto Hadiyanto ◽  
W Widayat
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Substrate Inhibition ◽  
Co2 Concentration ◽  
Co2 Absorption ◽  
Gas Flow Rate ◽  
Co2 Gas ◽  
Microalgae Biomass ◽  
Chlamydomonas Sp ◽  
Microalgae Growth

Mikroalga memiliki potensi dalam membiofiksasi CO2 dan dapat dimanfaatkan untuk mengurangi kadar CO2 dalam gas pencemar. Pertumbuhan mikroalga sangat dipengaruhi oleh konsentrasi gas CO2 di dalam gas pencemar. Tujuan penelitian ini adalah untuk mengeetahui kemampuan mikroalga Chlamydomonas sp yang dikultivasi dalam photobioreaktor tubular dalam penyerapan gas CO2 serta untuk mengetahui konsentrasi maksimum gas CO2 dalam umpan untuk memproduksi biomasa mikroalga yang optimal. Percobaan dilakukan dnegan memvariasi laju alir dari 0.03 -0.071 L/menit dan konsentrasi CO2 dalam umpan 10-30%. Hasil penelitian menunjukkan bahwa biomasa mikroalga dapat diproduksi dengan maksimal dengan konsentrasi gas CO2 20% dengan laju alir 0.07 L/min. Semakin tinggi laju alir maka produksi biomasa alga semakin besar. Kecepatan pertumbuhan alga maksimum terjadi pada 0.31 /hari. Pada konsentrasi gas CO2 30%, terjadi substrate inhibition yang disebabkan carbon dalam bentuk ion bicarbonate tidak dapat dikonsumsi lagi di dalam kultur alga. Kata kunci : Mikroalga, chlamydomonas sp, biofiksasi CO2, biogas Abstract Microalgae have a potential for CO2 biofixation and therefore can be used to reduce the CO2 concentration in the gas pollutants. Moreover, microalgae growth is strongly affected by the concentration of CO2 in the exhaust gas pollutants. The objective of this research was to investigate the ability of microalgae Chlamydomonas sp which was cultivated in a tubular photobioreactor for CO2 absorption as well as to determine the maximum concentration of CO2 in the feed gas to obtain optimum microalgae biomass. The experiments were performed by varying the gas flow rate of 0.03 -0.071 L / min and the concentration of CO2 in the feed of 10-30%. The results showed that the maximum biomass of microalgae can be produced with CO2 concentration of 20% vol with a flow rate of 0.07 L / min. The result also showed that increasing the gas flow rate, the greater of the production of algal biomass and the maximum algae growth rate occurred at 0.31 / day. At a concentration of 30% CO2 gas, it occurs a substrate inhibition due to inefficient of bicarbonate use by algae culture.

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.

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