scholarly journals CO2 Adsorption Capacity of Organic Alkali Sorbent CPEI from Polyethyleneimine

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Feng Wang ◽  
Lu Yu ◽  
Youhua Li ◽  
Dengfa Huang

Support-free cross-linked polyethyleneimine sorbent (CPEI) for CO2 capture was evaluated as the regenerable sorbent. The total amines available for the CO2 capture on CPEI were determined by the polyethyleneimine/glutaraldehyde ratio for the synthesis of CPEI. The CO2 capacity of CPEI in the slurry bubble column reactor reached 4.92 mmol/g, which is 1.97 times higher than that obtained under anhydrous conditions. The adsorption kinetics of CPEI in the reactor were investigated in terms of the CPEI amount, the CO2 fraction, the gas flow rate, temperature, and the total amines available. The experimental breakthrough curves for the sorbent were well-fitted with a fractional-order kinetic model. The modeling analysis found the influence of diffusion resistance on the adsorption is more significant than that of the driving force. The CO2 capacity of CPEI remained almost constant during the temperature swing adsorption/desorption cycles.

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5793
Author(s):  
Eero Inkeri ◽  
Tero Tynjälä

The demand for carbon capture is increasing over time due to rising CO2 levels in the atmosphere. Even though fossil emission could be decreased or even eliminated, there is a need to start removing CO2 from the atmosphere. The removed CO2 could be either stored permanently to a reservoir (CCS, Carbon Capture and Storage) or utilized as a raw material in a long-lasting product (CCU, Carbon Capture and Utilization). The capture of CO2 could be done by direct air capture, or capturing CO2 from biogenic sources. Amine absorption is the state-of-the-art method to capture CO2, but it has some drawbacks: toxicity, high heat demand, and sorbent sensitivity towards impurities such as sulfur compounds and degradation in cyclic operation. Another potential solvent for CO2 could be water, which is easily available and safe to use in many applications. The problem with water is the poorer solubility of CO2, compared with amines, which leads to larger required flow rates. This study analyzed the technical feasibility of water absorption in a counterflow bubble column reactor. A dynamic, one-dimensional multiphase model was developed. The gas phase was modeled with plug flow assumption, and the liquid phase was treated as axially dispersed plug flow. CO2 capture efficiency, produced CO2 mass flow rate, and the product gas CO2 content were estimated as a function of inlet gas and liquid flow rate. In addition, the energy consumption per produced CO2-tonne was calculated. The CO2 capture efficiency was improved by increasing the liquid flow rate, while the CO2 content in product gas was decreased. For some of the studied liquid flow rates, an optimum gas flow rate was found to minimize the specific energy consumption. Further research is required to study the integration and dynamical operation of the system in a realistic operation environment.


2021 ◽  
Vol 11 (16) ◽  
pp. 7724 ◽  
Author(s):  
Yu-Chun Chiang ◽  
Chih-Cheng Huang ◽  
Wei-Ting Chin

Electrospinning techniques have become an efficient way to produce continuous and porous carbon nanofibers. In view of CO2 capture as one of the important works for alleviating global warming, this study intended to synthesize polyacrylonitrile (PAN)-based activated carbon nanofibers (ACNFs) using electrospinning processes for CO2 capture. Different structures of PAN-based ACNFs were prepared, including solid, hollow, and porous nanofibers, where poly(methyl methacrylate) (PMMA) was selected as the sacrificing core or pore generator. The results showed that the PMMA could be removed successfully at a carbonization temperature of 900 °C, forming the hollow or porous ACNFs. The diameters of the ACNFs ranged from 500 to 900 nm, and the shell thickness of the hollow ACNFs was approximately 70–110 nm. The solid ACNFs and hollow ACNFs were microporous materials, while the porous ACNFs were characterized by hierarchical pore structures. The hollow ACNFs and porous ACNFs possessed higher specific surface areas than that of the solid ACNFs, while the solid ACNFs exhibited the highest microporosity (94%). The CO2 adsorption capacity on the ACNFs was highly dependent on the ratio of V<0.7 nm to Vt, the ratio of Vmi to Vt, and the N-containing functional groups. The CO2 adsorption breakthrough curves could be curve-fitted well with the Yoon and Nelson model. Furthermore, the 10 cyclic tests demonstrated that the ACNFs are promising adsorbents.


Author(s):  
Samira Taherkhani ◽  
Ali Khani

Introduction: In this study, nanosized zero-valent zinc (Zn0) as a reducing agent, simultaneously synthesized and immobilized on an oxidizing agent, ZnO photocatalyst for degradation of methyl orange (MO) from the aqueous solution. Materials and Methods: The prepared redox nanocomposite (nZn0-ZnO) was characterized by the XRD and SEM techniques. The prepared sample was separated by centrifuging. The preparation process of nZn0-ZnO including synthesis-immobilization, washing, and drying carried out under Argon gas flow. Moreover, the effect of temperature and kinetics reaction was studied. Results: The results showed that degradation efficiency of prepared redox nanocomposite was increased compared to each ZnO nanopowder and Zn0 under the same operational condition. The calculated activation energy for the degradation process was 4.05 KJ.mol-1. Finally, the results showed that the degradation processes followed pseudo first order kinetic model in the basic condition by the relative deviation modulus. Conclusion: As compared to ZnO nanopowder and Zn0, the prepared redox nanocomposite showed high degradation efficiency for the removal of methyl orange from the aqueous solution.


2020 ◽  
Vol 13 (1) ◽  
pp. 67-73
Author(s):  
Elaf Thamera ◽  
Salih Abduljabbar Rushdi

In this work, an absorption technology   was used actually to investigation the  mass transfer coefficient of carbon dioxide from a gaseous mixture (air, carbon dioxide) in  blended solution Monoethanolamine (MEA) and Diethanolamine (DEA)  in a bubble column reactor (BCR) . The bubble column reactor(BCR) was made of Plexiglas with 1.5 m high and 0.1 m inside diameter. The overall mass transfer coefficient (  was evaluated at different operating conditions , gas flow rate, air Flow rate ,liquid flow rate .Where the gas flow rates were 10, 15 and 20 L /min ,  air flow rate 100,150 and 200 L/h ,and liquid flow rate 5 ,10,15 L /min . This experiment  by   using  continuous   process with helping centrifugal  pump  . High-performance gas chromatographic (GC) was performed to evaluate  loading during absorption experiment . The  experimental results have shown that the   loading in range of  0.581-1.367 (mol  /mole amine),and the maximum value of overall mass transfer coefficient ( KG) was 0.04 S-1 .


2018 ◽  
Vol 156 ◽  
pp. 02015 ◽  
Author(s):  
Ratnawati Ratnawati ◽  
Dyah Arum Kusumaningtyas ◽  
Purbo Suseno ◽  
Aji Prasetyaningrum

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.


2010 ◽  
Vol 162 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Alicia García-Abuín ◽  
Diego Gómez-Díaz ◽  
José M. Navaza ◽  
Isabel Vidal-Tato

2002 ◽  
Vol 46 (4-5) ◽  
pp. 361-366 ◽  
Author(s):  
C.H. Ni ◽  
J.N. Chen ◽  
Y.C. Tsai ◽  
W.B. Chen ◽  
C.H. Chen

In this study, a pilot plant combined ozonation with sand filtration is established. Wastewater from the secondary effluent was taken as the sample for looking into the feasibility of domestic wastewater recovery and recycling. At the beginning, a series of hydraulic analysis and ozone transfer tests was conducted in the bubble column reactor. From these tests, it was found that when the gas flow is controlled to within 0.2∼1.0 L/min and liquid flow within 0.5∼2.5L/min, using series connected mixing tank model for our calculation, the result J (CSTR) is 1∼2. From the ozone transfer test it is known that the smaller the gas flow, the better the transfer rate, and the same pattern occurs on ozone gas concentration. After sand filtration and ozone treatment, the G/L ratio within the ozone column reactor can be maintained within 0.2∼0.4 and the ozone dosage within 8∼12 mg/L. The removal rate for coliform bacillus, BOD, turbidity and color is 99.96%, 62.2%, 89.6% and 67% respectively. After ozonation treatment, coliform bacillus content can be controlled under 10 CFU/mL, BOD under 10mg/L, turbidity within 2.0∼2.5 (NTU), and color within 10.3∼13.7 degree. The recycled water is almost colorless and odorless, and is capable of reaching the reference standard for recycled water.


2017 ◽  
Vol 20 (1) ◽  
Author(s):  
Jianbing Wang ◽  
Zhilin Xia ◽  
Zuhai Cao ◽  
Shaoxia Yang ◽  
Wanpeng Zhu

AbstractThis research investigated the establishment of a mathematical model for the ozonation of dimethyl phthalate (DMP) through the analysis of the mass transfer and reactions in a semi-batch bubble column reactor. Negative step tracer experiments were conducted with ozone as a tracer, which indicated that the gas phase is perfectly well mixed at the gas flow rate of 400 mL/min. Based on the results from ozone absorption experiments the mass transfer coefficient of ozone was determined to be 0.0054 s


2021 ◽  
Author(s):  
◽  
Stephen Okiemute Akpasi

Global climate change is one of the major threats facing the world today and can be due to increased atmospheric concentrations of greenhouse gases (GHGs), such as carbon dioxide (CO2). There is also an immediate need to reduce CO2 emissions, and one of the potential solutions for reducing CO2 emissions is carbon capture and storage (CCS). This work investigated the performance assessment of kaolinite and activated carbon (AC) adsorbent for CO2 capture. In particular, the effect of operating parameters such as temperature, bed height, inlet gas flow rate etc. on CO2 adsorption behaviour of the adsorbents was also investigated. Extensive research on the development of adsorbents that can adsorb large amounts of CO2 with low energy consumption has recently been carried out. In CO2 adsorption technology, the challenge is to develop an adsorbent that is not only non-toxic, eco-friendly, and cost-effective, but also has the potential to extract CO2 gas from a mixed gas stream selectively and effectively. Due to the possibility of a potential adsorbent due to its low cost, rich natural abundance and high mechanical and chemical stability, this study proposes kaolinite. As the presence of clay minerals in soils serves as a pollutant collector to enhance the atmosphere, kaolinite has the potential to be an efficient adsorbent for CO2 capture. Kaolinite was investigated as an adsorbent in this research to confirm if it is suitable for CO2 capture. Kaolinite/activated carbon composite adsorbents were synthesized. Sugarcane bagasse was used in preparing the activated carbon (AC). ZnCl2 was impregnated onto sugarcane bagasse during the preparation of activated carbon (AC) to improve the physical properties (surface area, pore size and pore volume) and the CO2 adsorption capacity of the activated carbon (AC) adsorbent developed. The materials were characterized and tested for CO2 adsorption (activated carbon and kaolinite). BET, FTIR and SEM studies were used to classify the adsorbents for their surface area and pore properties, functional groups, and surface morphology, respectively. BET analysis was conducted and the pore volume, pore size and surface area of the adsorbent materials were reported. Functional groups were actively present in the adsorption process. This was verified using FTIR spectroscopy. The kaolinite adsorbent was not feasible for CO2 capture. BET, SEM, and custom-built CO2 adsorption equipment have confirmed this. In contrast to literature, the CO2 adsorption capacity of kaolinite was low. This is due to the fact that kaolinite used in this study is not suitable as adsorbent for CO2 capture as they exhibited a low CO2 adsorption capacity. The results obtained in this study show that temperature, bed height and inlet gas flow rate influenced the adsorption behaviour of activated carbon (AC), kaolinite and kaolinite/activated carbon composite adsorbent during CO2 capture. At 30 0C, activated carbon (AC) exhibited an adsorption capacity of 28.97 mg CO2/g, the highest capacity among all the adsorbents tested. Kaolinite-activated carbon composite adsorbent offered CO2 adsorption capacities of 18.54 mg CO2/g. Kaolinite provides the lowest capacity of 12.98 mg CO2/g. In conclusion, this research verified that CO2 adsorption with kaolinite and activated carbon is favoured at low temperatures, low operating CO2 flowrates and high column bed height.


2013 ◽  
Vol 11 (1) ◽  
pp. 587-593 ◽  
Author(s):  
Antonio Blanco ◽  
Alicia García-Abuín ◽  
Diego Gómez-Díaz ◽  
Jose M. Navaza

Abstract This work analyses the influence of different experimental conditions over important hydrodynamic parameters of a bubble column reactor, such as bubble size distribution, gas hold-up and the gas–liquid interfacial area. The influence of gas flow-rate (18–40 L h–1) and reagent concentration (0–0.5 mol L–1) in the liquid phase upon these hydrodynamic parameters have been studied. The influence of experiment time must also be taken into account due to non-steady-state regime. Under these considerations, the chemical absorption rate changes throughout time, and it produces important changes upon the global absorption process, due to modifications in the gas–liquid interfacial area. The presence of a fast reaction in the liquid bulk has the highest influence upon interfacial area.


Sign in / Sign up

Export Citation Format

Share Document