https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18539 Wed 11 Apr 2018 14:38:57 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19369 2 capture processes. Using software developed in Matlab and existing knowledge of chemical equilibria, investigations into the fundamental properties of formulated amine solvents and their interaction with CO₂ have been carried out. A simple solvent formulation containing equimolar amounts of monoethanolamine (MEA), Amine 1, and a sterically hindered /tertiary amine, Amine 2, has been investigated here. Specifically, the role of Amine 2 in the overall equilibrium behaviour of amine blends is discussed. Systematic variations of the protonation constants and reaction enthalpies of Amine 2 over a range of typical values has revealed that significant improvement can be made in terms of absorption capacity, cyclic capacity, and overall absorption enthalpy in the blends when compared to the standard 5.0 M MEA solvent.]]> Wed 11 Apr 2018 14:03:51 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18618 Wed 11 Apr 2018 13:02:04 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32376 Tue 29 May 2018 11:49:00 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:52767 Tue 14 Nov 2023 15:12:48 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37763 Tue 13 Apr 2021 15:48:53 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:49925 9.0 (k7 = 6.99 × 103 M–1·s–1). Below this pH, the formation of protonated monocarbamic acid (DMEDACOOH2) via the pathway involving DMEDAH+ and CO2(aq) becomes active and contributes to the kinetics despite the 107-fold decrease in the rate constant between the two pathways. 1H and 13C NMR spectra as a function of decreasing pH (increasing HCl concentration) at 25.0 °C have been evaluated here to confirm the protonation events in DMEDA. Calculations of the respective DMEDA nitrogen partial charges have also been undertaken to support the NMR protonation study. A comparison of the DMEDA kinetic constants with the corresponding data for piperazine (PZ) reveals that despite the larger basicity of DMEDA, the enhanced and superior kinetic performance of PZ with CO2(aq) above its predicted Bronsted reactivity is not observed in DMEDA.]]> Thu 15 Jun 2023 11:34:48 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18737 Sat 24 Mar 2018 08:02:48 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20414 G) describing CO₂ absorption and NH₃ vapor loss in 3.0M NH₃ and blended 3.0M NH₃ solutions containing a wide range of K-SAR concentrations from 0.0 to 3.0M were determined using a wetted-wall column contactor at 15–25 °C and CO₂ loadings from 0.0 to 0.5(molCO₂/mol total amine). Additionally, prediction of equilibrium species distribution using fundamental chemical modelling software (ReactLab) in CO₂-loaded NH₃ containing blended solutions were used to explain our experimental results. Addition of K-SAR resulted in significant improvement of K_G of CO₂ absorption in NH₃ solutions, but also increased NH₃ vapor losses. The effect of temperature on K_G of CO₂ absorption in K-SAR solution was greater than in the NH₃/K-SAR blended solution. The improvement in mass transfer upon addition of K-SAR is due to the faster reaction of CO₂ with K-SAR than with NH₃. The greater loss of NH₃ upon addition of K-SAR can be ascribed to the availability of more free NH₃ and the decrease of solubility of CO₂ and NH₃ in the NH₃/K-SAR blended solution. The investigation of K_G of CO₂ and NH₃ vapor losses in NH₃ and other amines (PZ, 1-MPZ, DEA and MEA) blended solutions also proved the competition for CO₂ is one of the reasons for the increasing of NH₃ vapor losses.]]> Sat 24 Mar 2018 08:00:52 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19609 Sat 24 Mar 2018 07:58:24 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19303 m) and entropies (ΔS⁰_m) of the protonation reactions were also determined by the van't Hoff equation. It was found that sarcosine can maintain a higher pKₐ than the other amino acids studied at high temperatures. We also found that the CO₂ solubilities and overall mass-transfer coefficients of 5 m' sarcosinate (moles of sarcosine per kilogram of solution) at 333-353 K are higher than those of 30% MEA at 313-353 K. These results show that some possible benefits can be produced from the use of sarcosine as a fast solvent for CO₂ absorption at high temperatures. However, the pronotation reaction of sarcosine is the least exothermic among those of all amino acids studied. This could lead to a high regeneration energy consumption in the sarcosinate-based CO2 capture process.]]> Sat 24 Mar 2018 07:49:59 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27485 Sat 24 Mar 2018 07:25:40 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27484 Sat 24 Mar 2018 07:25:38 AEDT ]]>