scholarly journals Enhancing Absorption Performance of CO2 by Amine Solution through the Spiral Wired Channel in Concentric Circular Membrane Contactors

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 4
Author(s):  
Chii-Dong Ho ◽  
Hsuan Chang ◽  
Guan-Hong Lin ◽  
Thiam Leng Chew
Keyword(s):  
Flow Rate ◽  
Absorption Rate ◽  
Concentration Polarization ◽  
Co2 Concentration ◽  
Co2 Absorption ◽  
Countercurrent Flow ◽  
Circular Membrane ◽  
Concurrent Flow ◽  
Amine Solution ◽  
Membrane Contactors

The CO2 absorption rate by using a Monoethanolamide (MEA) solution through the spiral wired channel in concentric circular membrane contactors under both concurrent-flow and countercurrent-flow operations was investigated experimentally and theoretically. The one-dimensional mathematical modeling equation developed for predicting the absorption rate and concentration distributions was solved numerically using the fourth Runge–Kutta method under various absorbent flow rate, CO2 feed flow rate and inlet CO2 concentration in the gas feed. An economical viewpoint of the spiral wired module was examined by assessing both absorption flux improvement and power consumption increment. Meanwhile, the correlated average Sherwood number to predict the mass-transfer coefficient of the CO2 absorption mechanisms in a concentric circular membrane contactor with the spiral wired annulus channel is also obtained in a generalized and simplified expression. The theoretical predictions of absorption flux improvement were validated by experimental results in good agreements. The amine solution flowing through the annulus of a concentric circular tube, which was inserted in a tight-fitting spiral wire in a small annular spacing, could enhance the CO2 absorption flux improvement due to reduction of the concentration polarization effect. A larger concentration polarization coefficient (CPC) was achieved in the countercurrent-flow operations than that in concurrent-flow operations for various operations conditions and spiral-wire pitches. The absorption flux improvement for inserting spiral wire in the concentric circular module could provide the maximum relative increment up to 46.45%.

scholarly journals Conjugated Mass Transfer of CO2 Absorption through Concentric Circular Gas–Liquid Membrane Contactors

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1580
Author(s):  
Chii-Dong Ho ◽  
Hsuan Chang ◽  
Yih-Hang Chen ◽  
Jun-Wei Lim ◽  
Jing-Wei Liou
Keyword(s):  
Mass Transfer ◽  
Analytical Solutions ◽  
Absorption Rate ◽  
Liquid Membrane ◽  
Absorption Efficiency ◽  
Experimental Results ◽  
Co2 Absorption ◽  
Countercurrent Flow ◽  
Theoretical Predictions ◽  
Membrane Contactors

A new design of gas absorption that winds the permeable membrane onto an inner concentric tube to conduct a concentric circular gas–liquid membrane module has been studied theoretically in the fully developed region. An analytical formulation, referred to as conjugated Graetz problems, is developed to predict the concentration distribution and Sherwood numbers for the absorbent fluid flowing in the shell side and CO2/N2 gas mixture flowing in the tube side under various designs and operating parameters. The analytical solutions to the CO2 absorption efficiency were developed by using a two-dimensional mathematical modeling, and the resultant conjugated partial differential equations were solved analytically using the method of separation variables and eigen-function expansion in terms of power series. The predictions of CO2 absorption rate by using Monoethanolamide (MEA) solution in concentric circular membrane contactors under both concurrent- and countercurrent-flow operations are developed theoretically and confirmed with the experimental results. Consistency in both a good qualitative and quantitative sense is achieved between the theoretical predictions and experimental results. The advantage of the present mathematical treatment provides a concise expression for the chemical absorption of CO2 by MEA solution to calculate the absorption rate, absorption efficiency, and average Sherwood number. The concentration profiles with the mass-transfer Graetz number, inlet CO2 concentration, and both gas feed and absorbent flow rates are also emphasized. Both theoretical predictions and experimental results show that the device performance of the countercurrent-flow operation is better than that of the concurrent-flow device operation. The availability of such simplified expressions of the absorption rate and averaged Sherwood as developed directly from the analytical solutions is the value of the present study.

scholarly journals Augmenting CO2 Absorption Flux through a Gas–Liquid Membrane Module by Inserting Carbon-Fiber Spacers

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 302
Author(s):  
Luke Chen ◽  
Chii-Dong Ho ◽  
Li-Yang Jen ◽  
Jun-Wei Lim ◽  
Yu-Han Chen
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Carbon Fiber ◽  
Flow Rate ◽  
Absorption Rate ◽  
Absorption Efficiency ◽  
Co2 Absorption ◽  
Countercurrent Flow ◽  
Carbon Dioxide Absorption ◽  
Ptfe Membrane

We investigated the insertion of eddy promoters into a parallel-plate gas–liquid polytetrafluoroethylene (PTFE) membrane contactor to effectively enhance carbon dioxide absorption through aqueous amine solutions (monoethanolamide—MEA). In this study, a theoretical model was established and experimental work was performed to predict and to compare carbon dioxide absorption efficiency under concurrent- and countercurrent-flow operations for various MEA feed flow rates, inlet CO2 concentrations, and channel design conditions. A Sherwood number’s correlated expression was formulated, incorporating experimental data to estimate the mass transfer coefficient of the CO2 absorption in MEA flowing through a PTFE membrane. Theoretical predictions were calculated and validated through experimental data for the augmented CO2 absorption efficiency by inserting carbon-fiber spacers as an eddy promoter to reduce the concentration polarization effect. The study determined that a higher MEA feed rate, a lower feed CO2 concentration, and wider carbon-fiber spacers resulted in a higher CO2 absorption rate for concurrent- and countercurrent-flow operations. A maximum of 80% CO2 absorption efficiency enhancement was found in the device by inserting carbon-fiber spacers, as compared to that in the empty channel device. The overall CO2 absorption rate was higher for countercurrent operation than that for concurrent operation. We evaluated the effectiveness of power utilization in augmenting the CO2 absorption rate by inserting carbon-fiber spacers in the MEA feed channel and concluded that the higher the flow rate, the lower the power utilization’s effectiveness. Therefore, to increase the CO2 absorption flux, widening carbon-fiber spacers was determined to be more effective than increasing the MEA feed flow rate.

scholarly journals An Integrated Methodology towards Mitigation of Global Warming and Biomass Production for Biodiesel using Chlorella sorokiniana BTA 9031

2019 ◽  
Vol 8 (4) ◽  
pp. 3054-3058
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Methyl Esters ◽  
Research Work ◽  
Co2 Concentration ◽  
Chlorella Sorokiniana ◽  
Biodiesel Production ◽  
Co2 Absorption ◽  
Microalgal Biomass ◽  
Microalgal Cultivation

The rise of atmospheric carbon dioxide (CO2 )concentration as well as depletion of fossil fuel reserves calls for the development of clean and ecofriendly alternative fuel source. Recently, lipid rich microalgal biomass is being extensively studied for generation of biodiesel however, the expensesincurred on production of microalgal biomassis a significant hurdle. Almost 80 % of the production costis generated from the cultivation medium which majorly comprise of carbon, nitrogen and phosphate. If the microalgal cultivation could be linked to a CO2 capturing unit than the cost of production could be reduced to a large extent. CO2 absorption by means of aqueous amine solvents is known to be a mature technology and could be integrated with microalgal cultivation unit for efficient utilization of the captured CO2 . In this present research work, blended solution of piperazine (PZ) and2-amino2-methyl-1-propanol (AMP) (5/25 wt. %) was used to capture CO2 and then the captured CO2 was utilized as an inorganic carbon stream for growing Chlorella sorokiniana BTA 9031 for biodiesel production. The CO2rate absorption was governed by series of process variablesviz.solvent flow rate ranges (1.5 to 3) ×10⁻4 m 3 min-1 , absorption temperature (298 to 313) K,concentration of CO2 (10 to 15) kPa and gas flow rate(5 to 8) ×10⁻3 m 3 min-1 . The detected final biomass strengthofChlorella sorokiniana BTA 9031 was0.955g L-1 . The fatty acid methyl esters (FAME) determinedsubsequentlyacid transesterification was observed to contain fatty acids suitable for biodiesel production.

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.

scholarly journals CO2 Absorption Using Hollow Fiber Membrane Contactors: Introducing pH Swing Absorption (pHSA) to Overcome Purity Limitation

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 496
Author(s):  
Sayali Ramdas Chavan ◽  
Patrick Perré ◽  
Victor Pozzobon ◽  
Julien Lemaire
Keyword(s):  
Hollow Fiber ◽  
Recovery Rate ◽  
Hollow Fiber Membrane ◽  
Operating Conditions ◽  
Co2 Removal ◽  
Co2 Absorption ◽  
Fiber Membrane ◽  
Residual Content ◽  
Membrane Contactors ◽  
Ph Swing

Recently, membrane contactors have gained more popularity in the field of CO2 removal; however, achieving high purity and competitive recovery for poor soluble gas (H2, N2, or CH4) remains elusive. Hence, a novel process for CO2 removal from a mixture of gases using hollow fiber membrane contactors is investigated theoretically and experimentally. A theoretical model is constructed to show that the dissolved residual CO2 hinders the capacity of the absorbent when it is regenerated. This model, backed up by experimental investigation, proves that achieving a purity > 99% without consuming excessive chemicals or energy remains challenging in a closed-loop system. As a solution, a novel strategy is proposed: the pH Swing Absorption which consists of manipulating the acido–basic equilibrium of CO2 in the absorption and desorption stages by injecting moderate acid and base amount. It aims at decreasing CO2 residual content in the regenerated absorbent, by converting CO2 into its ionic counterparts (HCO3− or CO32−) before absorption and improving CO2 degassing before desorption. Therefore, this strategy unlocks the theoretical limitation due to equilibrium with CO2 residual content in the absorbent and increases considerably the maximum achievable purity. Results also show the dependency of the performance on operating conditions such as total gas pressure and liquid flowrate. For N2/CO2 mixture, this process achieved a nitrogen purity of 99.97% with a N2 recovery rate of 94.13%. Similarly, for H2/CO2 mixture, a maximum H2 purity of 99.96% and recovery rate of 93.96% was obtained using this process. Moreover, the proposed patented process could potentially reduce energy or chemicals consumption.

scholarly journals Assessment of carbon dioxide separation by amine solutions using electrolyte non-random two-liquid and Peng-Robinson models: Carbon dioxide absorption efficiency

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Arash Esmaeili ◽  
◽  
Zhibang Liu ◽  
Yang Xiang ◽  
Jimmy Yun ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Co2 Concentration ◽  
Liquid Hydrocarbon ◽  
Absorption Efficiency ◽  
High Reactivity ◽  
Proper Solution ◽  
Co2 Absorption ◽  
Carbon Dioxide Absorption ◽  
Operational Conditions ◽  
Wide Range

A high pressure carbon dioxide (CO2) absorption from a specific gas in a conventional column has been evaluated by the Aspen HYSYS simulator using a wide range of single absorbents and blended solutions to estimate the outlet CO2 concentration, absorption efficiency and CO2 loading to choose the most proper solution in terms of CO2 capture for environmental concerns. The property package (Acid Gas-Chemical Solvent) which is compatible with all applied solutions for the simulation in this study, estimates the properties based on an electrolyte non-random two-liquid (E- NRTL) model for electrolyte thermodynamics and Peng-Robinson equation of state for the vapor and liquid hydrocarbon phases. Among all the investigated single amines as well as blended solutions, piperazine (PZ) and the mixture of piperazine and monoethanolamine (MEA) have been found as the most effective absorbents respectively for CO2 absorption with high reactivity based on the simulated operational conditions.

scholarly journals EVALUASI KINERJA METHYL DIETHANOL AMINE (MDEA) DALAM PENYERAPAN KANDUNGAN H2S PADA PROSES PENGOLAHAN GAS ALAM

EKOLOGIA ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 45-51
Author(s):  
. Sutanto ◽  
Ade Heri Mulyati ◽  
. Hermanto
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Acid Gas ◽  
Amine Solution ◽  
A Value ◽  
Logarithmic Equation ◽  
Counter Current ◽  
Column Outlet ◽  
Sour Gas

Drilling natural gas contains water vapor (H2O) and contaminant gases such as CO2 and H2S which must be removed because it reduced the calorie value of the product. H2S gas is also corrosive, easily damaging equipment so that it increased maintenance costs. The process of removing CO2 and H2S gas uses MDEA (methyl diethanolamine). This study aims to determine the optimal concentration and flow rate of absorbent methyl diethanolamine (MDEA) to absorb H2S in the plant I gas flow in Energy Equity Epic (Sengkang) Pty.Ltd. The study was carried out with a steady MDEA mix absorbent flow rate (50% pure amine and 50% demineralization water) fixed at 13 US Gallons per minute flowing continuously at the upper absorber inlet, sour gas flow rate, at the bottom of the absorber inlet with variations in the flow gas namely 7,9,11,13,15,17 MMSCFD and is contacted with amine solution counter-current. Purified natural gas (sweet gas) produced from the top absorber column outlet with an H2S content below 10 ppm. The results showed that the greater the flow rate of gas inlet, the greater the acid gas absorbed. The  amount  of gas  entering and  exiting gas follows the  equation        y = 0.003 x - 2.2537. The ability of the amine solution to absorb H2S follows the logarithmic equation y = 0.167 ln (x) + 101.02 with a value of R = 0.9857, y is H2S absorbed by the amine solution and x is the H2S rate.

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