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  • 1.
    Bui, Thai Q.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Khokarale, Santosh G.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Shukla, Shashi Kant
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Mikkola, Jyri-Pekka
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Industrial Chemistry & Reaction Engineering, Department of Chemical Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, FI-20500 Åbo-Turku, Finland.
    Switchable Aqueous Pentaethylenehexamine System for CO2 Capture: an Alternative Technology with Industrial Potential2018Ingår i: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 6, nr 8, s. 10395-10407Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herein we report the application of polyamine pentaethylenehexamine (PEHA, 3,6,9,12-tetraazatetradecane-1,14-diamine) in CO2 absorption with both neat PEHA and aqueous solutions thereof. The absorption of molecular CO2 in pure PEHA and in PEHA-water systems resulted in the formation of two chemical species, namely, PEHA carbamate and bicarbonate. It was observed that, upon formation of these species, both the CO2 absorption capacity and CO2 absorption rate were controlled by the amount of water in the system. During the CO2 absorption, the neat PEHA and 92 wt % PEHA were capable of forming carbamate species only while other aqueous analogues with higher dilution allowed for the formation of both carbamate and bicarbonate species upon exceeding 8 wt % water in the mixture. The CO2 uptake steadily increased with an increase in the water concentration in the solvent mixture and reached the maximum value of 0.25 g of CO2/(g of solvent) in the case of 56 wt % PEHA in water. However, in the case of more dilute systems (i.e., <56 wt % PEHA in water), the trend reversed and the CO2 loading decreased linearly to 0.05 g of CO2/(g of solvent) for 11 wt % PEHA in water. Meanwhile, it usually took shorter time to achieve the full CO2 absorption capacity (equilibrium) with increasing water content in all cases. The C-13 NMR analysis was used to quantify the relative amount of PEHA carbamate and bicarbonate, respectively, in reaction mixtures. The Kamle-Taft parameters (alpha, beta, and pi*) of aqueous solutions for different concentrations of PEHA were also studied taking advantage of various solvatochromic dyes and correlated with the CO2 absorption capacity. The thermally induced switchable nature of CO2-saturated neat and aqueous PEHA solutions for transformation of ionic PEHA carbamate and bicarbonate moieties to molecular PEHA is also represented. A comparison between aqueous PEHA and aqueous monoethanolamine (industrial solvent) for CO2 capture is reported. Hence, most importantly, a switchable PEHA system is demonstrated for reversible CO2 absorption processes.

  • 2. Ma, Chunyan
    et al.
    Shukla, Shashi Kant
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Samikannu, Rakesh
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Mikkola, Jyri-Pekka
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Industrial Chemistry & Reaction Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Turku, Finland.
    Ji, Xiaoyan
    CO2 Separation by a Series of Aqueous Morpholinium-Based Ionic Liquids with Acetate Anions2020Ingår i: ACS Sustainable Chemistry & Engineering, E-ISSN 2168-0485, Vol. 8, nr 1, s. 415-426Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, CO2 absorption capacities in a series of aqueous N-alkyl-N-methylmorpholinium-based ILs with acetate as the counterpart anion were investigated. Among these ILs, N-butyl-N-methylmorpholinium acetate ([Bmmorp][OAc]) with the highest CO2 absorption capacity was screened for thermodynamic modeling. The non-random two-liquid model and the Redlich–Kwong equation of state (NRTL-RK model) were used to describe the phase equilibria. The CH4 absorption capacity in the aqueous [Bmmorp][OAc] was also measured in order to verify the results predicted from the thermodynamic modeling, and the comparison shows the reliability of the model prediction. The parameters were embedded into the commercial software Aspen Plus. After that, the aqueous [Bmmorp][OAc] solutions with 30–40 wt % of water were selected to carry out process simulation for CO2 separation from biogas, and it was found that using these aqueous [Bmmorp][OAc] gave rise to lower energy usage and smaller size of equipment than other physical solvents. The results suggest that aqueous [Bmmorp][OAc] solution can be used as an alternative to organic solvents and has the potential to decrease the cost of CO2 separation.

  • 3.
    Samikannu, Rakesh
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Shukla, Shashi Kant
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Samikannu, Ajaikumar
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Mikkola, Jyri-Pekka
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Åbo Akademi University, Process Chemistry Centre, Laboratory of Industrial Chemistry and Reaction Engineering, FI-20500 Turku, Finland.
    Lutidinium-Based Ionic Liquids for Efficient Dissolution of Cellulose2019Ingår i: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 43, nr 5, s. 2299-2306Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herein, we have studied the potential of lutidinium-based ILs (1-allyl-3,5-dimethylpyridinium chloride [3,5-ADMPy]Cl and 1-allyl-3,4-dimethylpyridinium chloride [3,4-ADMPy]Cl) in the dissolution of cellulose, and their structures were confirmed by 1H and 13C NMR spectra, respectively. [3,5-ADMPy]Cl exhibited the highest capacity in cellulose dissolution. In fact, it dissolved 20 wt% of cellulose within 12 min and 26 wt% of cellulose in 35 min at 118 °C. The crystallinity and morphology of native and regenerated cellulose were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM) and CP/MAS 13C NMR spectroscopy. These techniques clearly suggest that the crystallinity of cellulose is reduced upon treatment in lutidinium-based ILs. The thermogravimetric analysis (TGA) showed that regenerated cellulose had thermal stability close to that of native cellulose.

  • 4.
    Shukla, Shashi Kant
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Khokarale, Santosh G.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Bui, Thai Q.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Mikkola, Jyri-Pekka
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Industrial Chemistry and Reaction Engineering, Department of Chemical Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Åbo-Turku, Finland.
    Ionic Liquids: Potential Materials for Carbon Dioxide Capture and Utilization2019Ingår i: Frontiers in Materials, ISSN 2296-8016, Vol. 6, artikel-id 42Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The nonvolatility, structure-tunability and high CO2 uptake capacity render ionic liquids (ILs) the most exciting materials for the carbon dioxide (CO2) capture and fixation to value-added chemicals. The aim of this mini-review is to give a brief idea about the development of the potential ILs for CO2 capture, the mechanism involved in the CO2 binding and the application of ILs in the conversion of CO2 to useful chemicals. The mechanisms and nature of interactions in between IL-CO2 have been discussed in terms of the nature of cation, anion, presence of functional group and the extent of interaction between the components of ILs. The fixation of CO2 to linear and cyclic carbonates and electroreduction of CO2 to carbon-rich fuels in ILs has been accounted in detail. At the end, future challenges in terms of commercializing the ILs for CO2 capture and utilization technology are discussed.

  • 5.
    Shukla, Shashi Kant
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Mikkola, Jyri-Pekka
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Industrial Chemistry & Reaction Engineering, Department of Chemical Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Åbo-Turku, Finland.
    Intermolecular interactions upon carbon dioxide capture in deep-eutectic solvents2018Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, s. 24591-24601Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herein we report the CO2 uptake in potential deep-eutectic solvents (DESs) formed between hydrogen bond acceptors (HBAs) such as monoethanolammonium chloride ([MEA·Cl]), 1-methylimidazolium chloride ([HMIM·Cl]) and tetra-n-butylammonium bromide ([TBAB]) and hydrogen bond donors (HBDs) like ethylenediamine ([EDA]), diethylenetriamine ([DETA]), tetraethylenepentamine ([TEPA]), pentaethylenehexamine ([PEHA]), 3-amino-1-propanol ([AP]) and aminomethoxypropanol ([AMP]) and analyzed the outcome in terms of the specific polarity parameters. Among various combinations of HBAs and HBDs, [MEA·Cl][EDA]-, [MEA·Cl][AP]-, [HMIM·Cl][EDA]- and [HMIM·Cl][AP] showed excellent CO2 uptake which was further improved upon increasing the mole ratio of HBA : HBD from 1 : 1 to 1 : 4. The lowest CO2 uptake in [MEA·Cl][PEHA] (12.7 wt%) and [HMIM·Cl][PEHA] (8.4 wt%) despite the highest basicity of [PEHA] infers that the basicity is not the sole criteria for guiding the CO2 uptake but, in reality, CO2 capture in a DES relies on the interplay of H-bonding interactions between each HBA and HBD. The role of HBAs in guiding CO2 uptake was more prominent with weak HBDs such as [TEPA] and [PEHA]. The speciation of absorbed CO2 into carbamate, carbonate, and bicarbonate was favorable in DES characterized by comparable hydrogen bond donor acidity (α) and hydrogen bond acceptor basicity (β) values, whereas the conversion of carbamate to carbonate/bicarbonate was observed to depend on α. The addition of water in DES resulted in lower CO2 uptake due to the decreased basicity (β).

  • 6.
    Shukla, Shashi Kant
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Chemical Biological Centre (KBC).
    Mikkola, Jyri-Pekka
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Chemical Biological Centre (KBC) & Industrial Chemistry & Reaction Engineering, Department of Chemical, Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, FI-20500 Åbo-Turku, Finland.
    Unusual temperature-promoted carbon dioxide capture in deep-eutectic solvents: the synergistic interactions2019Ingår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 55, nr 27, s. 3939-3942Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A series of novel ethylenediamine(EDA)-based deep-eutectic solvents (DESs) gave rise to unexpectedly large carbon dioxide (CO2) capturing capacity at higher temperatures owing to the “synergetic interaction” between the donor and acceptor moieties.

  • 7.
    Shukla, Shashi Kant
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Nikjoo, Dariush
    Mikkola, Jyri-Pekka
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Is basicity the sole criterion for attaining high carbon dioxide capture in deep-eutectic solvents?2020Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A critical analysis of the role of Hammett basicity (H−) and aqueous basicity (pKa) in CO2 uptake in deep-eutectic solvents (DESs) suggests that neither H− nor pKa correlates with the CO2 w/w% capacity in the studied DESs. Instead, strong “synergistic interactions” between donor and acceptor moieties satisfactorily relate to the w/w% of CO2 in DESs.

1 - 7 av 7
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