And 2-amino-2-methyl-1-propanol Research Articles

Investigating proton shuttling and electrochemical mechanisms of amines in integrated CO2 capture and utilization

Carbon capture and utilization (CCU) technologies present a promising solution for converting CO2 emissions into valuable products. Here we show how amines, such as monoethanolamine (MEA) and 2-amino-2-methyl-1-propanol (AMP), influence the electrochemical CO2 reduction process in an integrated CCU system. Using in situ spectroscopic techniques, we identify the key roles of carbamate bond strength, proton shuttling, and amine structure in dictating reaction pathways on copper (Cu) and lead (Pb) electrodes. Our findings demonstrate that on Cu electrodes, surface blockage by ammonium species impedes CO₂ reduction, whereas on Pb electrodes, proton shuttling enhances the production of hydrocarbon products. This study provides additional insights into optimizing CCU systems by tailoring the choice of amines and electrode materials, advancing the selective conversion of CO₂ into valuable chemicals.

Experimental and computational study of binary mixture ethanolamine and 2-amino-2-methyl-1-propanol

The present work involves experimental and computational investigations into the density of pure and mixed states of ethanolamine (ET) and 2-amino-2-methyl-1-propanol (AMP) under a pressure of 1 atm and temperatures ranging from 293.15 K to 333.15 K The density data were used to derive the excess molar volume, thermal expansion coefficient, and isothermal coefficient of pressure excess molar enthalpy. The Redlich–Kister equation was employed to calculate the excess molar and its accompanying coefficients. In the gas phase, density functional theory (DFT) was utilized to explore the most stable structures of ET … ET, AMP … AMP, and the ET … AMP mixture. Molecular dynamics simulation (MD) was used to calculate the structural properties of these mixtures in the liquid phase. Radial distribution function (RDFs) combined distribution function (CDF) and spatial distribution function (SDF) in different mole fractions calculated in the liquid phase. The intramolecular and intermolecular interactions of ethanolamine and AMP were obtained using the radial distribution function in different molar fractions. It was found that the ethanolamine molecule has a greater tendency to form intramolecular hydrogen bonds, while the AMP molecule has a greater tendency to form intermolecular hydrogen bonds.

Process simulation and optimization for post-combustion CO2 capture pilot plant using high CO2 concentration flue gas as a source

This work mainly focuses on process simulation and optimization of a high-concentrated CO2 chemical absorption process using aqueous amine solutions based on both pilot plant data and process modeling. To optimize operating parameters for reducing energy consumptions, this study explores the influence of process structure and operational parameters on the product purity, capture rate, and energy consumption, which would provide theoretical and technical support for optimizing high-concentration CO2 capture. At first, the rate-based absorption/desorption models are established and well-verified by a total of 25 sets of pilot plant data, which shows high accuracy for reliable model predictions. Under an annual absorption capacity of 50 tons at a 90% capture rate and 95% product purity, the optimal case using Monoethanolamine (MEA) solution shows an increased CO2 capture rate of 12.37% and a decreased unit energy consumption of 22.5%. After flowsheet optimization, a new system of blended MEA, Methyl diethanolamine (MDEA), and 2-Amino-2-methyl-1-propanol (AMP) solution is designed to capturing high-concentrated CO2 under the same conditions. Compared with the MEA system, its specified energy consumption is reduced by 10.35% and its CO2 capture capacity increases by 11.6 tons annually.

Effect of Novel pH Regulators on Copper film Chemical Mechanical Polishing for Ruthenium-Based Copper Interconnect under Weak Alkalinity Conditions

For Ruthenium (Ru)-based copper (Cu) interconnects Cu film chemical mechanical polishing (CMP), it is crucial to select appropriate pH regulators in the slurry to ensure the chemical reactions and maintain the stability of the polishing chemical environment. In this study, the effects of inorganic pH regulator KOH, organic pH regulator diethanolamine (DEA), and 2-amino-2-methyl-1-propanol (AMP) on CMP and slurry properties of Cu film were compared. It was found when using AMP as a pH regulator, the Cu/Ru removal rate selectivity (RRS) can reach 598:1, the surface roughness of Cu film decreased to 0.76 nm, and the slurry can remain stable for at least 7 d. The performance order of the three pH regulators is AMP＞KOH＞DEA. Meanwhile, through experimental results and test analysis, it has been confirmed that AMP can also play a multifunctional role as a complexing agent, dispersant, and surfactant. Therefore, AMP can replace KOH as a new pH regulator in weak alkaline slurries. This result plays an important role in guiding the selection of organic pH regulators in the optimization of Cu film CMP slurry.

Synergistic effect of blended amines on carbon dioxide absorption: Thermodynamic modeling and analysis of regeneration energy

Chemical absorption using amine-based aqueous solutions is a promising approach for limiting CO2 emissions. This study evaluated the performance of commercial amines, including monoethanolamine (MEA), diethanolamine (DEA), diisopropanolamine (DIPA), N-methyldiethanolamine (MDEA), triethanolamine (TEA), and 2-amino-2-methyl-1-propanol (AMP), along with their binary mixtures, with a focus on their synergistic effect in reducing the regeneration energy. The thermodynamic behavior of these aqueous amine systems for CO2 capture was analyzed using the electrolyte nonrandom two-liquid model; the shortcut method was used to estimate the regeneration energy. The CO2 loading ratio, concentrations of the molecules and ions in the liquid phase, heat of absorption, pH, and regeneration energy were included in the analysis. Amine blending was found to synergistically lower the regeneration energy in the following two cases. First, blending carbamate-forming and non-carbamate-forming amines enhanced carbamate formation, thereby increasing the CO2 cyclic capacity and reducing the regeneration energy in the DIPA-MDEA and DEA-AMP systems. Second, the MEA-MDEA system revealed an optimal blending ratio for balancing different heat components (sensible, reaction, and latent heat). These findings offer a guide for selecting and blending amines to optimize the CO2 capture performance.

Emulsion Stability and CO2 Removal Performance of MDEA-AMP Blends with Tween-80 Surfactants

Carbon dioxide (CO2) is a corrosive and inflammable gas found in natural gas. The most widely technique used for CO2 separation in the natural gas industry is via amine absorption method. However, due to the corrosive nature of amines, researchers actively looking for an alternative method to separate CO2. Therefore, the emulsion liquid membrane (ELM) was developed to address this issue. In spite of that, it still remains as challenge to find suitable formulation to produce stable emulsion with good CO2 removal performance. In this study, the amine blend emulsion containing Methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) with Tween80 (Polysorbate-80) were prepared. An aqueous phase was formed by blending of MDEA and AMP in sodium hydroxide (NaOH) solution. The organic phase composed of kerosene and Tween-80 used as surfactant. The effect of varying concentrations of Tween-80 on the emulsion stability and CO2 absorption capacity of ELM were investigated in this study. The emulsion was prepared by mixing the aqueous and organic phases for 5 minutes at a speed of 10,000 rpm until it become homogenous. The CO2 absorption capacity was conducted in a rotating disc contactor column with a 2-bar pressure of CO2 gas supply. This study demonstrated that, by blending of 8% v/v MDEA and 4% v/v AMP with 10% v/v Tween-80, 56.89% of CO2 removal could be achieved while maintaining an emulsion stability of 95%.

The Effect of MDEA/AMP and Span-80 in Water-in-Oil (W/O) Emulsion for Carbon Dioxide Absorption

Emulsion liquid membrane (ELM) has been widely studied as an alternative method for amine absorption technology in the removal of acid gases such as carbon dioxide (CO2) and hydrogen sulphide (H2S). However, searching for stable ELM formulation with an enhanced CO2 absorption remains as challenge. Therefore, in this study, the aqueous solution containing a mixture of methyl diethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) in sodium hydroxide (NaOH) solution was introduced as a dispersed phase, kerosene as continuous phase and Span-80 acts as a surfactant for the formation of water-in-oil (W/O) emulsion. In this study, the dispersed phase consists of 8% v/v MDEA and 4% v/v AMP and the continuous phase which contains 6% v/v Span-80 produced a stable emulsion and exhibited 65.2% of CO2 removal. This study indicates that the introduction of blended amine able to produce stable emulsion with an enhanced CO2 removal.

Understanding the potential benefits of blended ternary amine systems for CO2 capture processes through 13C NMR speciation study and energy cost analysis

Aqueous blends of the three amines 2-aminoethanol (MEA), N-methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) were tested as sorbents for CO2 capture processes. We formulated three different blends with the same overall amine concentration (5M) but with different amine molar ratio, namely blend-1 (2M MEA+2M MDEA+1M AMP), blend-2 (1M MEA+2M MDEA+2M AMP) and blend-3 (2M MEA+1M MDEA+2M AMP). Their CO2 absorption and desorption performances were investigated in batch experiments in terms of CO2 equilibrium solubility, CO2 absorption at 40 °C and CO2 desorption at 100 °C as a function of time, and energy consumption during the regeneration process. The results were compared to those obtained under the same operating conditions with 5M aqueous MEA, the benchmark sorbent for CO2 absorption processes. The effect of the different amino composition on the CO2 capture mechanism was evaluated by identifying and quantifying the species formed during the capture process through an accurate 13C NMR speciation study. The results obtained showed that all formulated sorbents have higher desorption performance and require less energy for regeneration than conventional aqueous MEA, confirming that blending different alkanolamines has the potential to improve CO2 capture. In particular, blend-2 can be regarded as a promising sorbent for implementation in commercial systems, as it performed a desorption rate up to 5 times higher than conventional aqueous MEA, combined with a significantly lower relative heat duty for regeneration (41.5%) and lower operating costs for CO2 capture.

A hybrid chemo-biocatalytic system of carbonic anhydrase submerged in CO2-phillic sterically hindered amines for enhanced CO2 capture and conversion into carbonates

The present study highlights a hybrid approach to capture and convert carbon dioxide (CO2) from exhaust gases using bovine carbonic anhydrase (CA) submerged into aqueous amine solvents. Particularly, the sterically hindered amines have unique properties to absorb CO2 and also play a key role in wide range of industrial applications. In this work, the reaction kinetics of CO2 were studied in the aqueous phase of sterically hindered amines (SHAs), 2-amino-2-hyroxymethyl-1,3-propanediol (AHPD) and 2-amino-2-methyl-1-propanol (AMP), mixed with bovine CA as test and without CA as control using the stopped flow technique. The results showed a significant improvement in the rate of reaction between SHAs (either aqueous AHPD or aqueous AMP) and CO2 in the presence of CA. Moreover, the absorption capacity of SHA for CO2 and its initial absorption rate in presence of CA was significantly enhanced. The rate constants of pseudo first-order reaction of CO2 reacting with AHPD and AMP (each 0.5 kmol/m3) with varied concentration of CA were determined at temperature range of 298- 353 K. The aqueous AHPD and AMP systems in the presence of CA and control retained 65% of absorption capacity after 5 repetitive cycles. Also, the amine solvent captured CO2 was converted into calcium carbonate (CaCO3) which is white powder materials. The synthesized CaCO3 was characterized for its morphological and physicochemical properties using scanning electron microscopy (SEM) and Fourier transformer infrared spectroscopy (FTIR) etc. Overall, as the CA present is the amine solvent can efficiently convert the CO2 and that can be removed easily in the form of CaCO3 precipitates.

Density, Viscosity, and Refractive Index Measurements for Binary Mixtures of N-Methyldiethanolamine (MDEA), Diethanolamine (DEA), and 2-Amino-2-methyl-1-propanol (AMP) with 1-Ethyl-3-methylimidazolium Acetate ([Emim][Ac

Density, Viscosity, and Refractive Index Measurements for Binary Mixtures of <i>N</i>-Methyldiethanolamine (MDEA), Diethanolamine (DEA), and 2-Amino-2-methyl-1-propanol (AMP) with 1-Ethyl-3-methylimidazolium Acetate ([Emim][Ac

A New Sulfolane based Solvent for CO2 Capture

This study presents novel sulfolane based non-aqueous CO2 capture solvents, as an alternative solution for capturing CO2 from industrial processes. In order to select the most promising amine system, five different amines were tested by monitoring CO2 absorption and desorption processes using the time-base Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. During absorption experiments, we observed the formation of Monomethyl Carbonate (MMC) in diisopropylamine (DIPA) and 2-amino-2-methyl-1-propanol (AMP) systems, while carbamate was observed as the main product for the other three amine systems tested. In regeneration experiments, the MMC could be desorbed relatively easily from the amine solution at a mild temperature.

Amine-passivated ZnO electron transport layer for thermal stability-enhanced perovskite solar cells

n-Type zinc oxide (ZnO) has high electron mobility, good light transmittance, and a suitable work function and is considered to be a suitable electron transport material in perovskite solar cells (PSCs). However, the chemical compatibility between ZnO and perovskites is poor, making it difficult to prepare highly efficient and stable PSCs by a one-step spin coating method. Here, the ZnO surface is modified with three amino compounds, butylamine (BA), isobutylamine (IBA) and 2-amino-2-methyl-1-propanol (AMP). Three amino compounds can react with 3D perovskite to form a thin and more stable perovskite with a 2D structure, which can improve the stability of ZnO-based PSCs fabricated by one-step method. Interestingly, the conductivity of amine-modified ZnO is also improved due to the presence of amino (NH2) and hydroxyl (OH) groups which can induce the dipole polarization. The modification of amino compounds on the surface of ZnO can affect the hydrophilicity of ZnO surface that is related to the crystallization of perovskite film. Devices with IBA modification exhibit improved stability, and the power conversion efficiency (PCE) can reach 18.84%. Therefore, we provide a new strategy to improve the surface of the ZnO electron transport layer for high-performance PSCs fabricated by a one-step method.

Artificial Neural Networks (ANNs) for Density and Viscosity Predictions of CO2 Loaded Alkanolamine + H2O Mixtures

The physical properties, like density and viscosity, of alkanolamine + H2O (water) + CO2 (carbon dioxide) mixtures receive a significant amount of attention as they are essential in equipment sizing, mathematical modelling and simulations of amine-based post-combustion CO2 capture processes. Non-linear models based on artificial neural networks (ANNs) were trained to correlate measured densities and viscosities of monoethanol amine (MEA) + H2O, MEA + H2O + CO2, and 2-amino-2-methyl-1-propanol (AMP) + MEA + H2O + CO2 mixtures and results were compared with conventional correlations found in literature. For CO2-loaded aqueous amine mixtures, results from the ANN models are in good agreement with measured properties with less than 1% average absolute relative deviation (AARD). The ANN-based methodology shows much better agreement (R2 &gt; 0.99) between calculated and measured values than conventional correlations.

Process Simulations of the Direct Non-Aqueous Gas Stripping Process for CO2 Desorption

The integration of the direct steam stripping (DSS) process with organic working fluid promises a significant reduction in the energy penalty for the CO2 capture process. This work investigates the mechanisms of the mass transfer enhancement in direct pentane stripping (DPS) process using simulation methods. Through regressing the molecule-molecule interaction parameters, a quaternary system thermodynamic model (QSTM) is developed to successfully predict the vapor-liquid equilibrium of Amine/CO2/Pentane/H2O system. Three typical solvents, monoethanolamine (MEA), methyldiethanolamine (MDEA), and 2-amino-2-methyl-1-propanol (AMP) are studied in this work. The DPS process using 30 wt.% MEA, 30 wt.%MDEA, and 30 wt.% AMP exhibits the solvent regeneration energy of 2.55, 2.65, and 2.01 GJ/tCO2 under the optimal conditions, which is 34%, 32%, and 48% lower than of the conventional MEA-based process. DPS using MDEA shows an energy advantage over the other two solvents because of the high CO2 equilibrium partial p...

Thermal Degradation Rate and Kinetic Modeling of CO2-Loaded Amine Solvent Blends of 2-Amino-2-methyl-1-propanol and 1-Amino-2-propanol

Employing experimental kinetics data collected in this study, a power law rate equation for the thermal degradation of 1-amino-2-propanol (A2P) and 2-amino-2-methyl-1-propanol (AMP) in CO2-loaded blended solutions are investigated. The rate experiments were carried out at 120, 135 and 150 °C to accelerate thermal degradation. Kinetic data was collected to extract the initial rate equation from aqueous blended solutions of 0.0, 0.5, 1.5, 2.0, 2.5, and 3.5 M, AMP and A2P with CO2 loadings from 0.1 to 0.6, molCO2/molAMP+A2P. The power law rate equations for each amine in the solutions, along with pre-exponential factors and activation energies for each reaction are provided. For both AMP and A2P degradation, the activation energies for the reaction between AMP, A2P and CO2 presented lower values, while the pre-exponential factors were orders of magnitude higher. The presence of the second amine in these solutions has little impact on the degradation rate of the individual amines.

An Integrated Methodology towards Mitigation of Global Warming and Biomass Production for Biodiesel using Chlorella sorokiniana BTA 9031

The rise of atmospheric carbon dioxide (CO2)concentration as well as depletion of fossil fuel reserves calls for the development of clean and ecofriendly alternative fuel source. Recently, lipid rich microalgal biomass is being extensively studied for generation of biodiesel however, the expensesincurred on production of microalgal biomassis a significant hurdle. Almost 80 % of the production costis generated from the cultivation medium which majorly comprise of carbon, nitrogen and phosphate. If the microalgal cultivation could be linked to a CO2 capturing unit than the cost of production could be reduced to a large extent. CO2 absorption by means of aqueous amine solvents is known to be a mature technology and could be integrated with microalgal cultivation unit for efficient utilization of the captured CO2. In this present research work, blended solution of piperazine (PZ) and2-amino-2-methyl-1-propanol (AMP) (5/25 wt. %) was used to capture CO2 and then the captured CO2 was utilized as an inorganic carbon stream for growing Chlorella sorokiniana BTA 9031 for biodiesel production. The CO2rate absorption was governed by series of process variablesviz.solvent flow rate ranges (1.5 to 3) ×10⁻4 m3 min-1, absorption temperature (298 to 313) K,concentration of CO2 (10 to 15) kPa and gas flow rate(5 to 8) ×10⁻3 m3 min-1. The detected final biomass strengthofChlorella sorokiniana BTA 9031 was0.955g L-1. The fatty acid methyl esters (FAME) determinedsubsequentlyacid transesterification was observed to contain fatty acids suitable for biodiesel production.

Theoretical modeling of the mass transfer performance of CO2 absorption into DEAB solution in hollow fiber membrane contactor

4-diethylamino-2-butanol (DEAB), as a novel tertiary amine, shows a promising potential for CO2 capture. In this study, the mass transfer performance of CO2 absorption into aqueous DEAB solution in a non-wetted and partially-wetted mode of hollow fiber membrane contactor (HFMC) was theoretically investigated in comparison with that of monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP). A 2D mathematical model based on finite element method (FEM) was established to solve the steady-state continuity equations for the shell, tube and membrane sides simultaneously. The influences of the operating parameters on the CO2 absorption flux in HFMC including liquid and gas velocity and CO2 partial pressure were comprehensively investigated. The numerical results show that the CO2 absorption flux can increase with the increasing liquid velocity and CO2 partial pressure, and slightly increases with the increasing gas velocity. Moreover, the CO2 absorption performance of aqueous DEAB solution was further compared with different amine solutions, which reveals that the CO2 absorption flux of DEAB is higher than those of DEA, MDEA and AMP, and is also comparable to MEA. The analysis on the mass transfer resistance indicates that the proportion of the membrane mass transfer resistance increased rapidly from 13.7% to 75.3% as membrane wetting ratio increased from 0% to 20%. Instead of the liquid phase, the mass transfer in wetted membrane phase becomes the rate-controlling step ultimately. The increase in the membrane wetting leads to the significant decrease in CO2 absorption performance with 49.4% and 80.5% decrease in CO2 absorption flux and the overall mass transfer coefficient at membrane wetting ratio of 5% and 50%, respectively. Based on the analysis on enhancement factor, it demonstrates that the chemical reaction between CO2 and DEAB for the non-wetted mode generally occurs in the intermediate fast-instantaneous regime and gradually transfers to the instantaneous regime with membrane wetting.

Experimental measurement and assessment of equilibrium behaviour for phase change solvents used in CO2 capture

Phase change solvents are receiving increased attention in the effort to significantly reduce regeneration energy requirements in post combustion CO2 capture processes with chemical absorption. In this study, the phase behavior of various phase change, aqueous amine solutions, was experimentally investigated. A new experimental apparatus was developed and evaluated by determining the CO2 solubility in aqueous monoethanolamine (MEA) solutions at 40, 60 and 80 °C. Subsequently, new experimental data were obtained for aqueous solutions containing N,N-dimethylcyclohexylamine (DMCA), methylcyclohexylamine (MCA) and 2-amino-2-methyl-1-propanol (AMP) at 40, 60 and 90 °C that exhibit phase change behavior. It was observed that the investigated solutions present vapor – liquid equilibrium (VLE) at 40 °C and vapor–liquid-liquid equilibrium (VLLE) at 60 and 90 °C for CO2 partial pressures up to approximately 70 kPa. In addition, screening experiments were performed using sulfolane, which has been previously used for gas sweeting applications, instead of AMP in the DMCA-MCA mixture. However, such system presents relatively low CO2 solubility, compared to the aforementioned (DMCA-MCA-AMP) system and aqueous MEA solutions. Finally, additional screening experiments were performed for two aqueous DMCA – 3-methylaminopropylamine (MAPA) amine solutions at different concentrations.

Experimental studies on mass transfer performance for CO2 absorption into aqueous N,N-dimethylethanolamine (DMEA) based solutions in a PTFE hollow fiber membrane contactor

CO2 absorption performance for various blended N,N-dimethylethanolamine (DMEA) solutions in the presence of absorption promoters including Monoethanolamine (MEA), Piperazine (PZ), 2-(Ethylamino)ethanol (EAE), 2-(Methylamino)ethanol (MAE) and 2-Amino-2-methyl-1-propanol (AMP) was investigated in terms of CO2 absorption flux by using a polytetrafluoroethylene (PTFE) hollow fiber membrane contactor. The experimental results show that the CO2 absorption flux increases with a reasonable increase in liquid velocity, liquid temperature and total amine concentration. Also, the CO2 absorption flux can increase by increasing gas velocity, CO2 partial pressure but decrease with the increased lean CO2 loading. In addition, it can be found that all of the investigated activated amines can improve the CO2 absorption flux of aqueous DMEA solution. For fresh amine solution, the order of CO2 absorption flux for the investigated amine blends can be ranked as: DMEA < DMEA + AMP < DMEA + MEA < DMEA + EAE < DMEA + MAE < DMEA + PZ. By contrast, for the amine solution with CO2 loading of over 0.3 mol/mol, the order has also changed accordingly and can be ranked as: DMEA < DMEA + AMP < DMEA + EAE < DMEA + MAE < DMEA + MEA < DMEA + PZ. The DMEA + PZ mixture presents a significant improvement up to 52.44% in CO2 absorption flux compared to that of single DMEA solution, and can be considered as a promising alternative for CO2 capture.

Investigation of selective desulfurization performance of sterically hindered amines

We investigated the H2S/CO2 gas mixture absorption rate and selectivity of 2-(tert-butylamino)ethanol (TBE) and 2-amino-2-methyl-1-propanol (AMP) using a static gas absorption method. The H2S and CO2 gas mixture was pumped into a reaction kettle filled with sterically hindered amines solubilized in water. The influence of time on the H2S absorption rate and selectivity of the sterically hindered amine solutions was investigated.