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In this review, the H2S/CH4 separation properties of polymer membranes are presented and a new upper bound is proposed. In view of the existing problems and development prospects of various membranes, the corresponding opinions and advices are given.
Yulei Ma; Hongfang Guo; Roman Selyanchyn; Bangda Wang; Liyuan Deng; Zhongde Dai; Xia Jiang. Hydrogen sulfide removal from natural gas using membrane technology: a review. Journal of Materials Chemistry A 2021, 1 .
AMA StyleYulei Ma, Hongfang Guo, Roman Selyanchyn, Bangda Wang, Liyuan Deng, Zhongde Dai, Xia Jiang. Hydrogen sulfide removal from natural gas using membrane technology: a review. Journal of Materials Chemistry A. 2021; ():1.
Chicago/Turabian StyleYulei Ma; Hongfang Guo; Roman Selyanchyn; Bangda Wang; Liyuan Deng; Zhongde Dai; Xia Jiang. 2021. "Hydrogen sulfide removal from natural gas using membrane technology: a review." Journal of Materials Chemistry A , no. : 1.
Water-lean solvents are solvents for CO2 capture which contain at least one amine and one organic diluent. Carbamate-forming amines in nonaqueous water-lean solvents typically absorb CO2 through the formation of carbamate species. Conversely, tertiary amines in nonaqueous amino-organic mixtures cannot form carbamate nor undergo bicarbonate formation. However, protic organic diluents might take part in an alkylcarbonate formation pathway: in this route, the diluent is deprotonated by the amine, and its conjugate base is then able to react directly with CO2 to form an alkylcarbonate. This is an interesting reaction mechanism, as it offers a possibility for formulating solvents that deviate from the two most common reaction pathways for CO2 absorption (i.e., carbamate and bicarbonate formation). The present study introduces a simple way for evaluating alkylcarbonate-forming water-lean solvents based on the properties of its single constituents, namely the basicity of the amine and the autoprotolysis constant of the organic diluent. Our theoretical framework shows that higher CO2 absorption capacities can be obtained for solvents containing amines with high pKa and diluents with low pKs. We assess both the challenges and possibilities for alkylcarbonate-forming solvents and propose a framework for their development and utilization in the industry.
Ricardo R. Wanderley; Karen K. Høisæter; Hanna K. Knuutila. Signs of alkylcarbonate formation in water-lean solvents: VLE-based understanding of pKa and pKs effects. International Journal of Greenhouse Gas Control 2021, 109, 103398 .
AMA StyleRicardo R. Wanderley, Karen K. Høisæter, Hanna K. Knuutila. Signs of alkylcarbonate formation in water-lean solvents: VLE-based understanding of pKa and pKs effects. International Journal of Greenhouse Gas Control. 2021; 109 ():103398.
Chicago/Turabian StyleRicardo R. Wanderley; Karen K. Høisæter; Hanna K. Knuutila. 2021. "Signs of alkylcarbonate formation in water-lean solvents: VLE-based understanding of pKa and pKs effects." International Journal of Greenhouse Gas Control 109, no. : 103398.
A new and improved aerosol model has been developed and tested against experimental data. An e-NRTL equilibrium model for MEA was extended to cover sulphuric acid containing droplets and validated against new eboulliometer data in this work. The droplet model predicts emissions without demister installed in the absorber, within ± 20% and with demister, 30-80% of the measured emissions. The model predicts well the change in emissions from NG-based to coal-based exhaust. Under conditions reported in this work, the droplet number concentration was found to have a small effect on predicted emissions because of more MEA gas-phase depletion with high droplet concentrations and slower growth. The effects counteract each other. With significant MEA depletion in the gas phase, the emissions are largely determined by the mass transfer rate from the bulk liquid. The initial droplet sulphuric acid concentration had a minor effect on the outlet droplet size distribution. The effect on MEA emissions was significant: the emissions went up with increased initial sulphuric acid concentration. The effect of sulphuric acid was stronger for low inlet gas CO2 concentration (NG) than for coal-based exhaust. The increase in emissions is believed to be caused by the increase in overall driving force for MEA between bulk liquid phase and droplets. The log-normal model does not catch small inlet droplet sizes in the range below 20-30nm. These droplet sizes hardly grow in the absorber and water wash and in the total emissions, these droplets have a negligible impact on emissions.
H.F. Svendsen; H. Majeed; H.K. Knuutila; M. Hillestad; S. Evjen; T. Mejdell; A. Einbu; K.W. Hjarbo; G. Haugen; K.A. Hoff. Aerosol growth in CO2 absorption with MEA, modelling and comparison with experimental results. International Journal of Greenhouse Gas Control 2021, 109, 103390 .
AMA StyleH.F. Svendsen, H. Majeed, H.K. Knuutila, M. Hillestad, S. Evjen, T. Mejdell, A. Einbu, K.W. Hjarbo, G. Haugen, K.A. Hoff. Aerosol growth in CO2 absorption with MEA, modelling and comparison with experimental results. International Journal of Greenhouse Gas Control. 2021; 109 ():103390.
Chicago/Turabian StyleH.F. Svendsen; H. Majeed; H.K. Knuutila; M. Hillestad; S. Evjen; T. Mejdell; A. Einbu; K.W. Hjarbo; G. Haugen; K.A. Hoff. 2021. "Aerosol growth in CO2 absorption with MEA, modelling and comparison with experimental results." International Journal of Greenhouse Gas Control 109, no. : 103390.
Helium is an unrenewable noble gas produced from natural gas with a wide range of scientific, medical, and industrial applications. Due to the large differences in the kinetic diameters between helium (0.26 nm) and nitrogen (0.364 nm) or methane (0.38 nm), membrane technology has been considered a promising alternative to traditional technologies for helium recovery and purification. This paper systematically reviews the advances in membrane material development for helium separation in recent years. Gas permeation data presented in this work were collected from over 1000 membrane materials, including polymeric, inorganic, and mixed matrix membranes. Moreover, membrane processes for helium recovery and purification from natural gas were critically analyzed and discussed concerning technical feasibility, energy consumption, and separation costs. Challenges in helium purification using membrane technology were also discussed, and potential solutions have been suggested. Lastly, future perspectives on research directions on membrane material development and hybrid helium purification process design and optimization are proposed.
Zhongde Dai; Jing Deng; Xuezhong He; Colin A. Scholes; Xia Jiang; Bangda Wang; Hongfang Guo; Yulie Ma; Liyuan Deng. Helium separation using membrane technology: Recent advances and perspectives. Separation and Purification Technology 2021, 274, 119044 .
AMA StyleZhongde Dai, Jing Deng, Xuezhong He, Colin A. Scholes, Xia Jiang, Bangda Wang, Hongfang Guo, Yulie Ma, Liyuan Deng. Helium separation using membrane technology: Recent advances and perspectives. Separation and Purification Technology. 2021; 274 ():119044.
Chicago/Turabian StyleZhongde Dai; Jing Deng; Xuezhong He; Colin A. Scholes; Xia Jiang; Bangda Wang; Hongfang Guo; Yulie Ma; Liyuan Deng. 2021. "Helium separation using membrane technology: Recent advances and perspectives." Separation and Purification Technology 274, no. : 119044.
An in-house designed membrane process suitable for subsea natural gas dehydration was studied. The use of a membrane absorber together with a thermopervaporation (TPV) unit for solvent regeneration in a closed loop enables the effective and clean production of high-pressure natural gas close to the wellhead. This process avoids the continuous chemical injection for preventing hydrate formation in natural gas pipelines. The regeneration of the absorbent agent (triethylene glycol (TEG)) by TPV in the closed loop is highly energy-efficient, owing to the unlimited free cooling energy from the cold subsea water. In this work, the performance of membranes in TPV for TEG regeneration was evaluated experimentally for the first time. Morphological and permeation characterizations of an AF2400 thin-film composite membrane were carried out, and high separation factors outperforming the vapor–liquid equilibrium (VLE) were obtained for the solutions containing various water contents at feed temperatures ranging from 30 to 70 °C. The highest values of a separation factor (128,000) and a permeability (2380 (Barrer)) were obtained for the TEG solution containing 30 wt % water at 30 °C, while the highest water flux (468 (g/m2·h)) was reached at 70 °C. Moreover, the concentration polarization phenomenon induced by the temperature gradient was revealed in the membrane’s vicinity of the feed channel. A 3D computational fluid dynamics simulation was performed over the entire module to correct the driving force for a more precise assessment of the membrane permeance. The temperature and concentration profiles in the membrane module domains were explored, and a good agreement with experimental data was obtained.
Mahdi Ahmadi; Luca Ansaloni; Magne Hillestad; Liyuan Deng. Solvent Regeneration by Thermopervaporation in Subsea Natural Gas Dehydration: An Experimental and Simulation Study. Industrial & Engineering Chemistry Research 2021, 60, 6262 -6276.
AMA StyleMahdi Ahmadi, Luca Ansaloni, Magne Hillestad, Liyuan Deng. Solvent Regeneration by Thermopervaporation in Subsea Natural Gas Dehydration: An Experimental and Simulation Study. Industrial & Engineering Chemistry Research. 2021; 60 (17):6262-6276.
Chicago/Turabian StyleMahdi Ahmadi; Luca Ansaloni; Magne Hillestad; Liyuan Deng. 2021. "Solvent Regeneration by Thermopervaporation in Subsea Natural Gas Dehydration: An Experimental and Simulation Study." Industrial & Engineering Chemistry Research 60, no. 17: 6262-6276.
Eighteen structurally varied amines were subjected to harsh oxidative conditions, and their stability was assessed and seen in the context of biological and thermal stability. Steric effects play a large role in the stabilization of amines under oxidative conditions, and the presence of carbon dioxide plays a vital role in the degradation pathway of ethanolamine (MEA). Tertiary amines are generally very stable, and are known not to form carbamates to any large extent. Many steric effects play a vital role in stabilization, such as chain length, substituents located both close to and farther from the nitrogen atom, and bond strain. A correlation is seen between biodegradability and oxidative degradability, giving similar degradability in both cases. There are, however, promising exceptions to this, such as 3-(dimethylamino)-1-propylamine (DMAPA) and 2-dimethylaminoethanol (DMMEA), which are stable under oxidative conditions, but also biodegradable. Direct correlations between oxidative stability and ecotoxicity or thermal stability are not seen.
Vanja Buvik; Solrun J. Vevelstad; Odd G. Brakstad; Hanna K. Knuutila. Stability of Structurally Varied Aqueous Amines for CO2 Capture. Industrial & Engineering Chemistry Research 2021, 60, 5627 -5638.
AMA StyleVanja Buvik, Solrun J. Vevelstad, Odd G. Brakstad, Hanna K. Knuutila. Stability of Structurally Varied Aqueous Amines for CO2 Capture. Industrial & Engineering Chemistry Research. 2021; 60 (15):5627-5638.
Chicago/Turabian StyleVanja Buvik; Solrun J. Vevelstad; Odd G. Brakstad; Hanna K. Knuutila. 2021. "Stability of Structurally Varied Aqueous Amines for CO2 Capture." Industrial & Engineering Chemistry Research 60, no. 15: 5627-5638.
We introduce the addition of stable salts to aqueous MEA as a way of inhibiting oxidative degradation reactions. We performed oxidative degradation studies in aqueous MEA containing sodium chloride (NaCl) and potassium iodide (KI). These “salted amine solvents” have been shortened to SAS. The 2.0 %wt. and 1.0 %wt. KI SAS show remarkable oxidative degradation behavior. Loss of alkalinity after 42 days of oxidative degradation experiments with the 1.0 %wt. KI SAS was of 4%, whereas that of aqueous MEA was of 40% after only 21 days. We evaluated how the addition of stable salts impacts CO2 solubility, viscosity, and thermal degradation and corrosion behavior and verify negligible deviations from aqueous MEA. Thus, addition of stable salts affects oxidative degradation phenomena without deranging CO2 solubility or mass transfer rates. With the promising inhibition behavior of KI on MEA degradation, this work presents the initial steps towards making it a commercially viable degradation inhibitor.
Vanja Buvik; Ricardo R. Wanderley; Hanna K. Knuutila. Addition of potassium iodide reduces oxidative degradation of monoethanolamine (MEA). Chemical Engineering Science: X 2021, 10, 100096 .
AMA StyleVanja Buvik, Ricardo R. Wanderley, Hanna K. Knuutila. Addition of potassium iodide reduces oxidative degradation of monoethanolamine (MEA). Chemical Engineering Science: X. 2021; 10 ():100096.
Chicago/Turabian StyleVanja Buvik; Ricardo R. Wanderley; Hanna K. Knuutila. 2021. "Addition of potassium iodide reduces oxidative degradation of monoethanolamine (MEA)." Chemical Engineering Science: X 10, no. : 100096.
This work evaluates the possibility of employing a volatile co-solvent injection for recovering CO2 from loaded monoethanolamine at 120 °C under pressures above those achievable through regular desorption processes. This co-solvent would be fed directly into the reboiler, percolating the column and delivering higher operational pressures without significatively affecting the chemical equilibrium between CO2 and the amine. Removal of this co-solvent would be required before the lean amine is recirculated to the absorber. A shortcut methodology for screening possible co-solvent candidates is presented, and MESH calculations of hypothetical stripping processes employing the high-pressure desorption approach are performed to illustrate the expected behavior of these systems. Pressures above 500 kPa are theoretically obtainable through the use of co-solvents which are less volatile than CO2 but that are still gases at 25 °C and 101.325 kPa, such as isobutane and dimethyl ether. These co-solvents will leave the desorber fractioned between the distillate and the bottom product, thus requiring two additional separation process for recovery. Less volatile solvents will concentrate at the bottom stages of the desorber, while more volatile solvents will flow straight through the column all the way up to the distillate without effectively delivering pressures as high as desired. In other words, this methodology results in a delicate optimization problem of finding ideal volatilities and operational conditions. Though no detailed energy analysis is performed in this preliminary assessment, we have identified a promising opportunity for CO2 production at higher pressures and enumerated the issues one should be concerned with when looking further into high-pressure desorption.
Ricardo R. Wanderley; Hanna K. Knuutila. Evaluating the possibility of high-pressure desorption of CO2 via volatile co-solvent injection. Chemical Engineering Research and Design 2021, 169, 116 -134.
AMA StyleRicardo R. Wanderley, Hanna K. Knuutila. Evaluating the possibility of high-pressure desorption of CO2 via volatile co-solvent injection. Chemical Engineering Research and Design. 2021; 169 ():116-134.
Chicago/Turabian StyleRicardo R. Wanderley; Hanna K. Knuutila. 2021. "Evaluating the possibility of high-pressure desorption of CO2 via volatile co-solvent injection." Chemical Engineering Research and Design 169, no. : 116-134.
Pilot plant testing of amine solvents for post-combustion CO2 capture is an essential tool for fully understanding degradation behaviour and emission profiles under realistic process conditions. This review aims to summarise the lessons learned in different pilot campaigns, as well as to give recommendations how solvent stability and emissions can be monitored and assessed. A total of 18 different pilot plants and 29 individual campaigns were studied, of which the majority used ethanolamine and flue gas from coal-fired power plants. The findings of the review are that solvent stability data from different pilot plants show significantly higher operation time in which the solvent is stable, when extensive flue gas pretreatment is implemented. It was also found that no single degradation compound seems to suffice for the assessment of the degradation of a solvent, even for the widely studied ethanolamine process. Monitoring of the total liquid-phase heat stable salt concentration, as well as gas phase ammonia concentration may, however, give an informative picture of the state and degradation of the solvent. There seems to be a lack of universally applied analytical methods, which makes it difficult to compare one campaign or location to another. The implementation of validated and documented analytical standards in this regard will facilitate production of reproducible, reliable and comparable data for future solvent stability assessment.
Vanja Buvik; Karen K. Høisæter; Sorun J. Vevelstad; Hanna K. Knuutila. A review of degradation and emissions in post-combustion CO2 capture pilot plants. International Journal of Greenhouse Gas Control 2021, 106, 103246 .
AMA StyleVanja Buvik, Karen K. Høisæter, Sorun J. Vevelstad, Hanna K. Knuutila. A review of degradation and emissions in post-combustion CO2 capture pilot plants. International Journal of Greenhouse Gas Control. 2021; 106 ():103246.
Chicago/Turabian StyleVanja Buvik; Karen K. Høisæter; Sorun J. Vevelstad; Hanna K. Knuutila. 2021. "A review of degradation and emissions in post-combustion CO2 capture pilot plants." International Journal of Greenhouse Gas Control 106, no. : 103246.
Every year, a plethora of studies focused on developing water-lean solvents for CO2 capture is published in the scientific literature. More often than not, these studies lack a satisfactory contextualization with the previous body of work. The reasons for this are manyfold, but perhaps the main culprit is the multitude of possible diluent and amine constituents for water-lean solvent formulation. This multitude of options can render a comprehensive analysis of water-lean solvents and their common properties quite a challenging task. However, precisely because there is such a diversity of results and observations, the ordering and categorization of distinct phenomena involving water-lean solvents is the more essential. Although there are some novel sophisticated deployements for the concept of organo-amine mixtures (such as the CO2BOLs and the NAS for example), many works on water-lean solvents adopt a traditionalistic approach, one that is conceptually based on the mixing of a physical and a chemical absorbent to generate a so-called hybrid solvent. We have demonstrated in this review that this particular class of solvents have more in common than one could be initially led to believe, and set clear guidelines to contextualize past and future results in terms of CO2 solubility, kinetic rates, mass transfer rates and heat of regeneration analyses. By doing this, we have also identified the main knowledge gaps remaining in the field of water-lean solvents – namely, degradation and corrosion data, as well as pilot plant data. We also believe that our comprehensive categorization and discussion of past literature on water-lean solvents delivers an important trove of references for those willing to carry on working with organo-amine mixtures, traditional or otherwise. With this study, we aim to aid future researchers to have easy access to key concepts for discussing their results.
Ricardo R. Wanderley; Diego D.D. Pinto; Hanna K. Knuutila. From hybrid solvents to water-lean solvents – A critical and historical review. Separation and Purification Technology 2020, 260, 118193 .
AMA StyleRicardo R. Wanderley, Diego D.D. Pinto, Hanna K. Knuutila. From hybrid solvents to water-lean solvents – A critical and historical review. Separation and Purification Technology. 2020; 260 ():118193.
Chicago/Turabian StyleRicardo R. Wanderley; Diego D.D. Pinto; Hanna K. Knuutila. 2020. "From hybrid solvents to water-lean solvents – A critical and historical review." Separation and Purification Technology 260, no. : 118193.
Knowledge on the solubility of gases, especially carbon dioxide (CO2), in monoethylene glycol (MEG) is relevant for a number of industrial applications such as separation processes and gas hydrate prevention. In this study, the solubility of CO2 in MEG was measured experimentally at temperatures of 333.15, 353.15, and 373.15 K. Experimental data were used to validate Monte Carlo (MC) simulations. Continuous fractional component MC simulations in the osmotic ensemble were performed to compute the solubility of CO2 in MEG at the same temperatures and at pressures up to 10 bar. MC simulations were also used to study the solubility of methane (CH4), hydrogen sulfide (H2S), and nitrogen (N2) in MEG at 373.15 K. Solubilities from experiments and simulations are in good agreement at low pressures, but deviations were observed at high pressures. Henry coefficients were also computed using MC simulations and compared to experimental values. The order of solubilities of the gases in MEG at 373.15 K was computed as H2S > CO2 > CH4 > N2. Force field modifications may be required to improve the prediction of solubilities of gases in MEG at high pressures and low temperatures.
Noura Dawass; Ricardo R. Wanderley; Mahinder Ramdin; Othonas A. Moultos; Hanna K. Knuutila; Thijs J. H. Vlugt. Solubility of Carbon Dioxide, Hydrogen Sulfide, Methane, and Nitrogen in Monoethylene Glycol; Experiments and Molecular Simulation. Journal of Chemical & Engineering Data 2020, 66, 524 -534.
AMA StyleNoura Dawass, Ricardo R. Wanderley, Mahinder Ramdin, Othonas A. Moultos, Hanna K. Knuutila, Thijs J. H. Vlugt. Solubility of Carbon Dioxide, Hydrogen Sulfide, Methane, and Nitrogen in Monoethylene Glycol; Experiments and Molecular Simulation. Journal of Chemical & Engineering Data. 2020; 66 (1):524-534.
Chicago/Turabian StyleNoura Dawass; Ricardo R. Wanderley; Mahinder Ramdin; Othonas A. Moultos; Hanna K. Knuutila; Thijs J. H. Vlugt. 2020. "Solubility of Carbon Dioxide, Hydrogen Sulfide, Methane, and Nitrogen in Monoethylene Glycol; Experiments and Molecular Simulation." Journal of Chemical & Engineering Data 66, no. 1: 524-534.
Numerous studies have been reported on CO2 facilitated transport membrane synthesis, but few works have dealt with the interaction between material synthesis and transport modelling aspects for optimization purposes. In this work, a hybrid fixed-site carrier membrane was prepared using polyallylamine with 10 wt% polyvinyl alcohol and 0.2 wt% graphene oxide. The membrane was tested using the feed gases with different relative humidity and at different CO2 partial pressures. Selected facilitated transport models reported in the literature were used to fit the experimental data with good agreement. The key dimensionless facilitated transport parameters were obtained from the modelling and data fitting. Based on the values of these parameters, it was shown that the diffusion of the amine-CO2 reaction product was the rate-controlling step of the overall CO2 transport through the membrane. It was shown theoretically that by decreasing the membrane selective layer thickness below the actual value of 1 µm to a value of 0.1 µm, a CO2 permeance as high as 2500 GPU can be attained while maintaining the selectivity at a value of about 19. Furthermore, improving the carrier concentration by a factor of two might shift the performances above the Robeson upper bound. These potential paths for membrane performance improvement have to be confirmed by targeted experimental work.
Bouchra Belaissaoui; Elsa Lasseuguette; Saravanan Janakiram; Liyuan Deng; Maria-Chiara Ferrari. Analysis of CO2 Facilitation Transport Effect through a Hybrid Poly(Allyl Amine) Membrane: Pathways for Further Improvement. Membranes 2020, 10, 367 .
AMA StyleBouchra Belaissaoui, Elsa Lasseuguette, Saravanan Janakiram, Liyuan Deng, Maria-Chiara Ferrari. Analysis of CO2 Facilitation Transport Effect through a Hybrid Poly(Allyl Amine) Membrane: Pathways for Further Improvement. Membranes. 2020; 10 (12):367.
Chicago/Turabian StyleBouchra Belaissaoui; Elsa Lasseuguette; Saravanan Janakiram; Liyuan Deng; Maria-Chiara Ferrari. 2020. "Analysis of CO2 Facilitation Transport Effect through a Hybrid Poly(Allyl Amine) Membrane: Pathways for Further Improvement." Membranes 10, no. 12: 367.
This work aims to understand oxygen solubility in pure and aqueous amine solvents for CO2 capture. Commercially available dissolved oxygen sensors were studied to evaluate whether these can be used for measuring oxygen solubility in the carbon capture processes. It also aims to understand the possible discrepancies from realistic concentrations of oxygen when using a dissolved oxygen sensor. Two independent measurement principles were used for this purpose, both electrochemical and optical. Furthermore, a Winkler titration method was used to aid the validation of the sensors as well as understanding salting-out effects. A simple model for predicting oxygen solubility in CO2-loaded ethanolamine solutions was made, which also has potential for predicting oxygen solubility in other loaded amine solutions. The results of the study show that dissolved oxygen sensors may be applied for measurement of oxygen concentrations in amine solutions and that different amines and different concentrations in water only show small variations in oxygen solubility. The sensors may also be used in CO2-loaded amine solutions, but here the increased conductivity of the solution may give a higher measured concentration of oxygen, than it is in reality. In ethanolamine, the consumption of oxygen is faster than the mass transfer of oxygen from gas to liquid phase, giving lower concentrations of oxygen than it should be in absence of a chemical reaction between oxygen and amine.
Vanja Buvik; Ida M. Bernhardsen; Roberta V. Figueiredo; Solrun J. Vevelstad; Earl Goetheer; Peter van Os; Hanna K. Knuutila. Measurement and prediction of oxygen solubility in post-combustion CO2 capture solvents. International Journal of Greenhouse Gas Control 2020, 104, 103205 .
AMA StyleVanja Buvik, Ida M. Bernhardsen, Roberta V. Figueiredo, Solrun J. Vevelstad, Earl Goetheer, Peter van Os, Hanna K. Knuutila. Measurement and prediction of oxygen solubility in post-combustion CO2 capture solvents. International Journal of Greenhouse Gas Control. 2020; 104 ():103205.
Chicago/Turabian StyleVanja Buvik; Ida M. Bernhardsen; Roberta V. Figueiredo; Solrun J. Vevelstad; Earl Goetheer; Peter van Os; Hanna K. Knuutila. 2020. "Measurement and prediction of oxygen solubility in post-combustion CO2 capture solvents." International Journal of Greenhouse Gas Control 104, no. : 103205.
Alarming increase in global CO2 emissions warrants acceleration of CO2 capture technologies. In this work, testing of pre-pilot scale membrane modules containing hybrid facilitated transport membranes in hollow fiber configuration is reported. The tests were carried out using real flue gas from a slipstream in the Colacem cement plant located in Gubbio, Italy. With the fabricated modules, CO2 flux of up to 750 NL m−2h−1 with a CO2 permeate purity ranging from 50 to 55 vol% was recorded. All pre-pilot membrane modules showed increased CO2 permeance in industrial testing (1.5 to 1.9x higher) compared to laboratory evaluation owing to the reliable water profile and high temperature of the flue gas from the chimney. Influence of operating parameters (e.g., pressures in the feed and permeate) were studied. Long-term testing showed no obvious reduction in permeation performance. Furthermore, the membranes with mobile carriers when exposed to the feed gas containing SOx and NOx exhibited good resistance to performance deterioration despite high concentrations of acidic impurities. Simulation studies based on validated experimental performance under industrial conditions reveal the high potential of the fabricated membranes as an efficient separation unit capable of achieving industrial capture rate and CO2 purity requirements using a relatively low membrane area.
Saravanan Janakiram; Fabio Santinelli; Riccardo Costi; Arne Lindbråthen; Giuseppe Marino Nardelli; Kris Milkowski; Luca Ansaloni; Liyuan Deng. Field trial of hollow fiber modules of hybrid facilitated transport membranes for flue gas CO2 capture in cement industry. Chemical Engineering Journal 2020, 413, 127405 .
AMA StyleSaravanan Janakiram, Fabio Santinelli, Riccardo Costi, Arne Lindbråthen, Giuseppe Marino Nardelli, Kris Milkowski, Luca Ansaloni, Liyuan Deng. Field trial of hollow fiber modules of hybrid facilitated transport membranes for flue gas CO2 capture in cement industry. Chemical Engineering Journal. 2020; 413 ():127405.
Chicago/Turabian StyleSaravanan Janakiram; Fabio Santinelli; Riccardo Costi; Arne Lindbråthen; Giuseppe Marino Nardelli; Kris Milkowski; Luca Ansaloni; Liyuan Deng. 2020. "Field trial of hollow fiber modules of hybrid facilitated transport membranes for flue gas CO2 capture in cement industry." Chemical Engineering Journal 413, no. : 127405.
Scrap containing NdFeB is a valuable resource for the production of NdFeB magnets as the demand for these materials grows. One of the challenges is to recover the rare earths or the NdFeB alloy powder in a clean and cost effective manner so that it can be re-processed into new magnets rather than becoming lost to landfill. Work on using hydrogen to process scrap magnets (HPMS) has been shown to be successful when targeting hard disk drives. Currently, there is a lack of information on reliable methods to separate out NdFeB from other scrap sources such as automotive drives. In the near future, with increasing sales and electrification of cars, the automotive sector could be an important source for Dy containing magnets. In this paper, the hydrogen processing of scrap magnets has been demonstrated as an extraction method for NdFeB from automotive rotors for the first time, with the aim to examine the viability of this recycling process and learn lessons for design for recycling. Thus leading to the sustainable production of these components. Significant challenges were outlined when applying the hydrogen process to rotors with embedded magnets. After the extraction, further process steps may also be needed to separate epoxy coatings, as sieving could only reduce the carbon content to 1420 ppm, compared to 770 ppm in the base alloy. The gravimetric measurements also confirmed that Dy additions increase both the initiation and absorption time for hydrogen decrepitation. Hence, a higher hydrogen pressure will be required to speed up the process.
Christian Jönsson; Muhammad Awais; Lydia Pickering; Malik Degri; Wei Zhou; Andy Bradshaw; Richard Sheridan; Vicky Mann; Allan Walton. The extraction of NdFeB magnets from automotive scrap rotors using hydrogen. Journal of Cleaner Production 2020, 277, 124058 .
AMA StyleChristian Jönsson, Muhammad Awais, Lydia Pickering, Malik Degri, Wei Zhou, Andy Bradshaw, Richard Sheridan, Vicky Mann, Allan Walton. The extraction of NdFeB magnets from automotive scrap rotors using hydrogen. Journal of Cleaner Production. 2020; 277 ():124058.
Chicago/Turabian StyleChristian Jönsson; Muhammad Awais; Lydia Pickering; Malik Degri; Wei Zhou; Andy Bradshaw; Richard Sheridan; Vicky Mann; Allan Walton. 2020. "The extraction of NdFeB magnets from automotive scrap rotors using hydrogen." Journal of Cleaner Production 277, no. : 124058.
The configuration of thin film composite (TFC) in the form of hollow fiber is desired for gas separation membranes to achieve better gas permeation and higher packing density. In this work, we developed and tested TFC hollow fiber membranes with a defect-free, ultrathin (200 nm) hybrid facilitated transport selective layer consisting of three phases, i.e., a host polymeric matrix with fixed-site carriers, a 2D inorganic filler, and, a CO2-philic mobile carrier. The effect of lateral size of graphene oxide (GO)-based fillers on CO2 permeation were studied in detail, and the modified size-optimized porous GO (pGO) fillers were found to enhance CO2 permeation at a very low loading of 0.2 wt%. The optimized hybrid materials were then combined with selected mobile carriers, which interact with CO2 reversibly to form carbonate/carbene-CO2 adduct to further enhance the CO2 permeation performance. The resulting hybrid facilitated transport membranes with mobile carriers showcase a CO2 permeance of up to 825 GPU with a CO2/N2 separation factor of 31 and a CO2/CH4 of 20. These membranes also exhibit increased resistance to carrier saturation phenomena typical of facilitated transport membranes, showing potential for CO2 separation applications also at elevated pressures.
Saravanan Janakiram; Juan Luis Martín Espejo; Karen Karolina Høisæter; Arne Lindbråthen; Luca Ansaloni; Liyuan Deng. Three-phase hybrid facilitated transport hollow fiber membranes for enhanced CO2 separation. Applied Materials Today 2020, 21, 100801 .
AMA StyleSaravanan Janakiram, Juan Luis Martín Espejo, Karen Karolina Høisæter, Arne Lindbråthen, Luca Ansaloni, Liyuan Deng. Three-phase hybrid facilitated transport hollow fiber membranes for enhanced CO2 separation. Applied Materials Today. 2020; 21 ():100801.
Chicago/Turabian StyleSaravanan Janakiram; Juan Luis Martín Espejo; Karen Karolina Høisæter; Arne Lindbråthen; Luca Ansaloni; Liyuan Deng. 2020. "Three-phase hybrid facilitated transport hollow fiber membranes for enhanced CO2 separation." Applied Materials Today 21, no. : 100801.
In this study, cellulose nanofibrils (CNF) of high charge (H-P-CNF) and screened size (H-P-CNF-S) were fabricated by increasing the charge of phosphorylated cellulose nanofibrils (P-CNFs) during the pre-treatment step of CNF production. Results show that the H-P-CNF have a significantly higher charge (3.41 mmol g-1) compared with P-CNF (1.86 mmol g-1). Centrifugation of H-P-CNF gave a supernatant with higher charge (5.4 mmol g-1) and a reduced size (H-P-CNF-S). These tailored nanocelluloses were added to polyvinyl alcohol (PVA) solutions and the suspensions were successfully coated on porous polysulfone (PSf) supports to produce thin-film nanocomposite membranes. The humid mixed gas permeation tests show that CO2 permeability increases for membranes with the addition of H-P-CNF-S by 52% and 160%, compared with the P-CNF/PVA membrane and neat PVA membrane, respectively.
Ragne Marie Lilleby Helberg; Jonathan Ø. Torstensen; Zhongde Dai; Saravanan Janakiram; Gary Chinga-Carrasco; Øyvind W. Gregersen; Kristin Syverud; Liyuan Deng. Nanocomposite membranes with high-charge and size-screened phosphorylated nanocellulose fibrils for CO2 separation. Green Energy & Environment 2020, 6, 585 -596.
AMA StyleRagne Marie Lilleby Helberg, Jonathan Ø. Torstensen, Zhongde Dai, Saravanan Janakiram, Gary Chinga-Carrasco, Øyvind W. Gregersen, Kristin Syverud, Liyuan Deng. Nanocomposite membranes with high-charge and size-screened phosphorylated nanocellulose fibrils for CO2 separation. Green Energy & Environment. 2020; 6 (4):585-596.
Chicago/Turabian StyleRagne Marie Lilleby Helberg; Jonathan Ø. Torstensen; Zhongde Dai; Saravanan Janakiram; Gary Chinga-Carrasco; Øyvind W. Gregersen; Kristin Syverud; Liyuan Deng. 2020. "Nanocomposite membranes with high-charge and size-screened phosphorylated nanocellulose fibrils for CO2 separation." Green Energy & Environment 6, no. 4: 585-596.
Realization of suitable membrane-based technology for efficient CO2 capture to mitigate climate change relies on the development of thin-film composite (TFC) membranes with superior separation performance. Graphene oxide (GO), due to its 2D morphology, intrinsic strength and chemical compatibility, was used as a nanofiller to enhance CO2 separation performance and stability of a facilitated transport membrane. SHPAA (sterically hindered polyallylamine)-based blend matrix was selected as the polymeric matrix material in this work. The high aspect ratio of GO-based fillers, when coupled with optimized coating protocol, resulted in TFC membranes of ultrathin (200 nm) selective layers with the in-plane orientation of nanoplatelets, leading to enhanced separation properties that can be retained for long term. Porous graphene oxide (pGO) was also incorporated as nanofillers, resulting in significantly improved gas permeation at a very low filler loading of 0.2 wt%; A CO2 permeance of up to 607 GPU with a CO2/N2 separation factor of 36 in flat-sheet configuration was documented. Chemical modification of GO with PEG groups was found to further increase the selectivity of the membranes but reduces the CO2 permeance, showing a CO2/N2 separation factor of 90 with a CO2 permeance of 205 GPU. The effect of various 2D nanoplatelets on CO2 transport properties in the membranes of hydrophilic PVA (polyvinyl alcohol) matrix and facilitated transport SHPAA/PVA matrix was elucidated with respect to the nanofiller property and loading.
Saravanan Janakiram; Juan Luis Martín Espejo; Xinyi Yu; Luca Ansaloni; Liyuan Deng. Facilitated transport membranes containing graphene oxide-based nanoplatelets for CO2 separation: Effect of 2D filler properties. Journal of Membrane Science 2020, 616, 118626 .
AMA StyleSaravanan Janakiram, Juan Luis Martín Espejo, Xinyi Yu, Luca Ansaloni, Liyuan Deng. Facilitated transport membranes containing graphene oxide-based nanoplatelets for CO2 separation: Effect of 2D filler properties. Journal of Membrane Science. 2020; 616 ():118626.
Chicago/Turabian StyleSaravanan Janakiram; Juan Luis Martín Espejo; Xinyi Yu; Luca Ansaloni; Liyuan Deng. 2020. "Facilitated transport membranes containing graphene oxide-based nanoplatelets for CO2 separation: Effect of 2D filler properties." Journal of Membrane Science 616, no. : 118626.
Subsea natural gas reservoirs are usually saturated with water vapor that causes corrosion in pipelines and forms hydrates blocking pipes and installations. In this work, the viability of the subsea natural gas dehydration in a non-porous membrane contactor was evaluated experimentally and by modeling. A flat sheet composite membrane is employed as the membrane interface and a structured packing turbulence promoter was installed at the gas side. The water flux and the outlet dew point were measured at different operating conditions (e.g., pressures, liquid and gas flow rates). To estimate simultaneously the permeability, overall mass transfer coefficient, and outlet water content, a systematic approach was applied and a 1D-2D model was developed bypassing the liquid phase mass transfer resistance and solved numerically coupled with a developed correlation for axial dispersion coefficient. The results show an increase in transmembrane water flux to the highest values of 72 g/m2h and 53 g/m2h with increasing gas flow rate and pressure to 500 ml/min and 11 bara, respectively. The effect of using a turbulence promoter was evaluated, and a good agreement between the simulated and experimental results was obtained. The mass transfer resistance of a dense layer was found to be dominating compared to that of gas and liquid phase and the high pressure and high gas flow rate are favored in this process. This study shows that membrane contactor enables effective water separation under subsea conditions. Installation of a turbulence promoter in the gas phase significantly reduced the water content in the outlet gas stream.
Mahdi Ahmadi; Arne Lindbråthen; Magne Hillestad; Liyuan Deng. Subsea natural gas dehydration in a membrane contactor with turbulence promoter: An experimental and modeling study. Chemical Engineering Journal 2020, 404, 126535 .
AMA StyleMahdi Ahmadi, Arne Lindbråthen, Magne Hillestad, Liyuan Deng. Subsea natural gas dehydration in a membrane contactor with turbulence promoter: An experimental and modeling study. Chemical Engineering Journal. 2020; 404 ():126535.
Chicago/Turabian StyleMahdi Ahmadi; Arne Lindbråthen; Magne Hillestad; Liyuan Deng. 2020. "Subsea natural gas dehydration in a membrane contactor with turbulence promoter: An experimental and modeling study." Chemical Engineering Journal 404, no. : 126535.
In this study, three zeolitic imidazolate frameworks (ZIFs) with different shapes – particles (0D), microneedles (1D) and leaves (2D) - were synthesized by tuning the polymeric additive. These ZIFs have been dispersed into Pebax 2533 matrix with a loading varying from 0 to 20 wt.%. The resultant mixed matrix membranes (MMMs) have been systemically characterized by various techniques. Mixed gas permeation experiment was also employed to evaluate the CO2 separation performance. The results show that there exists an optimal ZIF loading for these three series of membranes, but the values are highly dependent on the morphologies of the added ZIFs. The membranes containing ZIF particles and microneedles display the highest CO2 permeability and CO2/N2 selectivity simultaneously at 10 wt.% loading, while a much lower loading, i.e., ~ 5 wt.% is the optimized value for ZIF leaves. Moreover, the increment in CO2 permeability is related to the ZIFs’ morphology and the order is 0D < 1D < 2D. On the other hand, the effects of the morphology on selectivity seems to be the opposite, with ZIF of 0D structure showing the highest selectivity. Moreover, the influences of adding ZIF fillers on the performances of the resultant MMMs under varied operating temperatures and the feed pressures were also investigated. The membrane with 10 wt.% 1D ZIF shows the highest increment in CO2 permeability (727.4 Barrer) with the CO¬2/N2 selectivity of ~ 14 at 60 oC.
Jing Deng; Zhongde Dai; Liyuan Deng. Effects of the Morphology of the ZIF on the CO2 Separation Performance of MMMs. Industrial & Engineering Chemistry Research 2020, 59, 14458 -14466.
AMA StyleJing Deng, Zhongde Dai, Liyuan Deng. Effects of the Morphology of the ZIF on the CO2 Separation Performance of MMMs. Industrial & Engineering Chemistry Research. 2020; 59 (32):14458-14466.
Chicago/Turabian StyleJing Deng; Zhongde Dai; Liyuan Deng. 2020. "Effects of the Morphology of the ZIF on the CO2 Separation Performance of MMMs." Industrial & Engineering Chemistry Research 59, no. 32: 14458-14466.