Mitigating NH3 Vaporization from an Aqueous Ammonia Process for CO2 Capture

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Wojciech M. Budzianowski
Keyword(s):  
Flow Rate ◽  
Co2 Capture ◽  
Flue Gas ◽  
Aqueous Ammonia ◽  
Value Added ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Co2 Absorption ◽  
Falling Film ◽  
Major Drawback

An aqueous ammonia process (AAP) offers several advantageous technological features over other existing reactive absorption-based CO2 capture processes such as increased CO2 absorption loading capacity, no oxidative solvent degradation, no corrosion problems, high CO2 absorption fluxes and low energy input needed for solvent regeneration. It has also the potential of capturing multiple flue gas components (SO2, NOX, and CO2) and producing value added chemicals, such as ammonium sulfate, ammonium nitrate and ammonium bicarbonate, which are commonly used as fertilizers. Unfortunately, a major drawback of the AAP is NH3 volatility resulting in NH3vaporization to the flue gas. Therefore, the current article presents the results of experimental and numerical investigations directed at in-depth understanding of the AAP and at developing of new methods for mitigating the unwanted NH3 vaporization. For this purpose three types of reactor configurations are studied: (i) packed bed, (ii) falling film and (iii) membrane. The bench-scale experiments realized in the counter-current packed bed reactor reveal, that NH3 vaporization can be minimized under the conditions of low temperature, pH, and flow rate of flue gas and under the conditions of high pressure and flow rate of aqueous ammonia. Further, from the detailed 2D modeling of the AAP realized in the falling film reactor it is found, that NH3 vaporization can be mitigated by making use of the mechanisms of negative enhancement of mass transfer and of migrative mass transport. Finally, the potential benefits of using membrane facilitated AAP reactors are discussed.

scholarly journals Carbon Dioxide Absorption in a Fabricated Wetted-Wall Column Using Varying Concentrations of Aqueous Ammonia

2014 ◽  
Vol 13 (2) ◽  
pp. 9
Author(s):  
H.E.E. Ching ◽  
L.M.P. Co ◽  
S.I.C. Tan ◽  
S.A. Roces ◽  
N.P. Dugos ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Steady State ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Flue Gas ◽  
Carbon Capture ◽  
Aqueous Ammonia ◽  
Co2 Absorption ◽  
Wetted Wall Column

Due to the continued increasing levels of CO2 emissions that is contributing to climate change, CO2 mitigation technologies, particularly carbon capture and storage, are being developed to address the goal of abating CO2 levels. Carbon capture technologies can be applied at the pre-combustion, oxy-fuel combustion, and post-combustion stages, the latter being the most widely used due to its flexibility. Among the several CO2 separation processes available for carbon capture, absorption is the most widely used where amine solutions are used as absorbents. This paper highlights the use of a wetted wall column fabricated by Siy and Villanueva (2012) and simulated flue gas to determine the performance of CO2 absorption in terms of the percentage of CO2 absorbed, the steady state time, and the overall gas mass transfer coefficient. The concentrations used were 1, 5, 10, and 15% NH3(aq) at a constant temperature range of 12-17ºC, solvent flow rate of 100 mL/min, and simulated flue gas flow rate of 2 L/min. It was found that increasing the solvent concentration resulted in a proportional increase both in the percentage of CO2 absorbed and the overall gas mass transfer coefficient. The average percentage of CO2 absorbed ranged within 52.25% to 95.29% while the overall mass transfer coefficient ranged from 0.1843 to 0.7746 mmol/m2∙s∙kPa. However, erratic behavior was seen for the time required for the system to reach steady state. Using Design ExpertTM for analysis, the results showed that the effect of varying the concentration had a significant effect on the percentage of CO2 absorbed and the overall gas mass transfer coefficient. The results proved that the greater the aqueous ammonia concentration, the greater the percentage of CO2 absorbed. The range of 5-10% aqueous ammonia is recommended because the percentage of CO2 absorbed peaks at an average of 92% beyond the range of 5-10%.

scholarly journals Continuous Production of Lipase-Catalyzed Biodiesel in a Packed-Bed Reactor: Optimization and Enzyme Reuse Study

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Hsiao-Ching Chen ◽  
Hen-Yi Ju ◽  
Tsung-Ta Wu ◽  
Yung-Chuan Liu ◽  
Chih-Chen Lee ◽  
...  
Keyword(s):  
Flow Rate ◽  
Immobilized Lipase ◽  
Continuous Production ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Molar Ratio ◽  
System Response ◽  
Biodiesel Synthesis ◽  
Substrate Molar Ratio ◽  
Molar Conversion

An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in atert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of molar conversion. On the basis of ridge max analysis, the optimum conditions were as follows: flow rate 0.1 mL/min, temperature52.1∘C, and substrate molar ratio 1 : 4. The predicted and experimental values of molar conversion were83.31±2.07% and82.81±.98%, respectively. Furthermore, the continuous process over 30 days showed no appreciable decrease in the molar conversion. The paper demonstrates the applicability of using immobilized lipase and a packed-bed reactor for continuous biodiesel synthesis.

scholarly journals New Approaches in Modeling and Simulation of CO2 Absorption Reactor by Activated Potassium Carbonate Solution

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 78
Author(s):  
Maria Harja ◽  
Gabriela Ciobanu ◽  
Tatjána Juzsakova ◽  
Igor Cretescu
Keyword(s):  
Mathematical Model ◽  
Potassium Carbonate ◽  
Energy Savings ◽  
Co2 Concentration ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Co2 Absorption ◽  
Operational Parameter ◽  
Proposed Model ◽  
Strong Relation

The increase of CO2 concentration in the atmosphere is in strong relation with the human-induced warming up due to industrial processes, transportation, etc. In order to reduce the CO2 content, end of pipe post-combustion methods can be used in addition to other methods and techniques. The CO2 capture by absorption in potassium carbonate–bicarbonate activated solutions remains a viable method. In this study, a mathematical model for a packed bed reactor has been developed and tested. The mathematical model is tested for an industrial reactor based on CO2 absorption in Carsol solutions. The proposed model was validated by resolving for CO2 and water content, carbonate–bicarbonate, concentrations etc. For each operational parameter the error was calculated. The error for CO2 concentration is up to 4%. The height of the packed reactor is calculated as function of CO2 concentration in the final gas phase. The validated model can also be used for absorbing other CO2 streams taking into account the fact that its efficiency was proved in industrial scale. Future reactors used for CO2 absorption should consist of two parts in order to use partially regenerated solutions in the first part, with significant energy savings in the operational costs.

scholarly journals WALL EFFECT OF A PACKED BED WITH PELLET PARTICLES

2018 ◽  
Vol 56 (2A) ◽  
pp. 31-36
Author(s):  
Tran Duy Hai
Keyword(s):  
Flow Rate ◽  
Particle Diameter ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Radial Coordinate ◽  
Flow Profile ◽  
Local Velocity ◽  
Gas Velocity ◽  
Bed Height ◽  
Small Ratio

Fluid flow profile is a dominate role in the performance of packed bed reactor. In small ratio of column-to-particle diameter, velocity pattern is strongly affected by voidage distribution, which depends on radial coordinate, flow rate and bed height. In this study, effects of voidage distribution to gas velocity profile in a packed bed with pellet particles was empirically investigated. Uniformity of local velocity at the top of the bed was clearly observed with decreasing of bed height and flow rate. For 400 mm of bed height, the measured velocities are a well fitting to Fahien and Stankovich model for any expected flow rate.

scholarly journals Modeling and Optimization of Carbon Dioxide Removal in Packed Bed Column Reactor

2020 ◽  
Vol 8 (3) ◽  
pp. 8-13
Author(s):  
K. Thirugnanasambandham
Keyword(s):  
Carbon Dioxide ◽  
Process Parameters ◽  
Flow Rate ◽  
Co2 Capture ◽  
Packed Bed ◽  
Operating Conditions ◽  
Feed Flow Rate ◽  
Statistical Design Of Experiments ◽  
Packed Bed Column ◽  
Column Reactor

Global warming due to greenhouse gases has become a serious global issue. Extensive efforts are being made to fighting this phenomenon through carbon capture as carbon dioxide (CO2) is its major contributor. This study focused on CO2 capture in packed bed column reactor using Poly-(D) glucosamine under the various process parameters such as temperature, feed flow rate and mass of the adsorbent. Statistical design of experiments was carried out in order to analysis the effect process parameters on the capacity of CO2 capture in packed bed column. The obtained results show that feed flow rate has the significant affect compared to others. The maximum of 956 mg of CO2 is captured under the following operating conditions; temperature of 40oC, feed flow rate of 30 ml/min and 0.25 g of the Poly-(D) glucosamine. The ability of Poly-(D) glucosamine to capture the CO2 in packed bed column is confirmed.

scholarly journals Capturing CO2 from Biogas by MEA (Monoethanolamine) using Packed Bed Scrubber

2020 ◽  
Vol 4 (2) ◽  
pp. 105
Author(s):  
Iqbal Nur Daiyan ◽  
Leila Kalsum ◽  
Yohandri Bow
Keyword(s):  
Flow Rate ◽  
Combustion Process ◽  
Packed Bed ◽  
Co2 Absorption ◽  
Absorption Column ◽  
Fossil Energy ◽  
Spray Tower ◽  
Biogas Purification ◽  
Carbon Dioxide Co2 ◽  
Reduction Of Co2

Biogas adalah salah satu sumber energi terbarukan yang dapat dimanfaatkan sebagai pengganti energi fosil. Biogas sebagian besar mengandung metan (CH4) dan karbon dioksida (CO2). Kandungan CO2 pada biogas mengurangi efisiensi pada proses pembakaran dan dapat menyebabkan korosi pada komponen-komponen logam yang kontak langsung dengan biogas. Pemurnian biogas dengan absorpsi merupakan suatu cara untuk menurunkan kadar CO2 yang terkandung, dan meningkatkan kandungan CH4 pada biogas sehingga biogas yang dihasilkan dapat digunakan sebagai bahan bakar. Penelitian ini ditujukkan untuk mempelajari pengaruh konsentrasi monoethanolamine (MEA) dan laju alir absorben terhadap penurunan kadar CO2 yang terkandung dalam biogas. Proses absorpsi CO2 dilakukan pada scrubber tipe spray tower, scrubber yang digunakan pada penelitian ini berbahan akrilik dengan diameter 64 mm, panjang scrubber 750 mm, tinggi packing pada scrubber 500 mm dan dengan kapasitas 1.5 m3. Laju alir biogas yang digunakan 26 L/menit dengan variasi laju alir larutan MEA sebesar 0,5, 1 dan 1,5 L/menit dan variasi konsentrasi larutan MEA sebesar 1, 3, 5, dan 7M. Hasil penelitian menunjukkan pada laju alir larutan MEA 1,5 L/menit dengan konsentrasi larutan MEA 7M dapat menurunkan CO2 dari 8,53% menjadi 0,10%, dan dapat meningkatkan kandungan metana (CH4) dari 69,24% menjadi 81,20%.Biogas is a renewable energy source that can be used as a substitute for fossil energy. Biogas mostly contains methane (CH4) and carbon dioxide (CO2). The content CO2 in biogas reduces the efficiency of the combustion process and cause corrosion in metal components when direct contact with biogas. Biogas purification using absorption method can reduce levels of CO2 contained and increase levels of CH4  then the biogas produced can be used as fuel. This research study the effect of monoethanolamine (MEA) concentration and absorbent flow rate on the reduction of CO2 contained in biogas. CO2 absorption process is carried out by a spray tower type scrubber. It consisted of an acrylic absorption column (64 mm in diameter, 750 mm in height, 500 mm in packing height and 1.5 m3 in capacity). Biogas flow rate used is 26 L/min with variation of the flow rate of MEA 0.5, 1, and 1,5 L/min and concentration of MEA solution 1, 3, 5, and 7M. The results showed that the flow rate of MEA 1.5 L/min with a concentration of 7M MEA solution can reduce CO2 from 8.53% to 0.10% and can increase the methane (CH4) load from 69.24% to 81.20%.

scholarly journals Packed-Bed Reactor Study of NETL Sample 196c for the Removal of Carbon Dioxide from Simulated Flue Gas Mixture

2012 ◽  
Author(s):  
James S. Hoffman ◽  
Sonia Hammache ◽  
McMahan L. Gray ◽  
Daniel J. Fauth ◽  
Henry W. Pennline
Keyword(s):  
Carbon Dioxide ◽  
Flue Gas ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Gas Mixture

Simultaneous Absorption of SO2 and NO Using Sodium Chlorate/Urea Absorbent in a Rotating Packed Bed

2014 ◽  
Vol 908 ◽  
pp. 187-190
Author(s):  
Mei Jin ◽  
Guo Xian Yu ◽  
Fang Wang ◽  
Ping Lu
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Flue Gas ◽  
Gas Flow ◽  
Packed Bed ◽  
Sodium Chlorate ◽  
Experimental Conditions ◽  
Flow Rates ◽  
Simultaneous Absorption ◽  
Rotating Packed Bed

In this work, simultaneous absorption of SO2and NO from N2-NO-SO2simulated flue gas using sodium chlorate as the additive and urea as the reductant was investigated experimentally in a rotating packed bed. In RPB, various rotational speeds, gas flow rates and liquid flow rates were studied by means of the removal efficiency of SO2and NO. The experimental results showed that the removal efficiency of SO2was higher than 99.00% under various experimental conditions and, at the same time, the removal efficiency of NO exhibited different results under various experimental conditions. The simultaneous NO removal efficiency of 82.45% and the SO2removal efficiency of 99.49% could be obtained under the N2flow rate of 0.5 m3/h, SO2flow rate of 6 mL/min, the NO flow rate of 4 mL/min, the rotational speed of 460 rpm and the absorbent flow rate of 40 L/h.

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