Amine Systems Research Articles

Analysis of natural antibodies during the development of phantom pain syndrome

We determined natural antibodies (e-Abs) to the regulators of the main systems of biochemical homeostasis: β-endorphin, serotonin, dopamine, histamine, orphanin, angiotensin, GABA, glutamate, bradykinin, vasopressin, thrombin, α-2-macroglobulin in individuals with phantom pain syndrome (FBS), resulting from amputation after injury. It has been established that each patient has an individual immunoprofile, but for all of them there is a significant increase in the level of antibodies to serotonin, histamine and angiotensin, which reflect the chronicity of the pain syndrome and do not depend on the self-assessment of the severity of FBS. Determining the role of regulators of biochemical homeostasis in the development of phantom pain showed that with high, moderate and weak severity of FBS, the biogenic amine and angiotensinergic systems are activated. A decrease in FBS intensity normalizes deviations in all immunological parameters. The level of e-Abs for the pain (β-endorphin) and analgesic (orphanin) systems are significant only at low FBS. Monitoring the individual profile of e-Abs to endogenous regulators allows us to obtain an objective picture of the pain status of the patient’s body.

Comparative Review for Enhancing CO2 Capture Efficiency with Mixed Amine Systems and Catalysts.

This study investigates methods to enhance the efficiency of CO2 capture using organic amine absorption and compares the performance of traditional and novel amine solvents. It reviews various single-component and mixed amine absorbents, as well as catalysts used in these methods, highlighting the superiority of mixed amine absorbents over single-component amine absorbents in CO2 absorption and desorption. Additionally, the study explores the catalytic mechanisms and effects of catalysts in the CO2 absorption/desorption process with amine solvents and provides an outlook on future research directions. The aim is to promote the widespread adoption of organic amine absorption technology in industrial applications and to contribute to the development of more sustainable and efficient CO2 capture technologies.

Chemically Degradable Vitrimers Based on Divanillin Imine Diepoxy Monomer and Aliphatic Diamines for Enhanced Carbon Fiber Composite Applications

This study presents the development of a diglycidyl monomer containing two imine groups that can act as dynamic and reversible bonds. During the curing of the monomer with two different amine hardeners, we confirmed the formation of new imine groups due to the transamination reaction between the imine groups of the diepoxy monomer with the amine groups of the hardener. The effect of this structural change was observed in the stress relaxation behavior, resulting in the overlapping of two different relaxation modes. The analytical modelling was able to extract two distinct characteristic relaxation times using a double-element Maxwell model. A second characterization of the stress relaxation process by frequency sweep experiments was performed to corroborate the results obtained, confirming speedy stress relaxation. Acid-catalyzed hydrolysis was performed on the studied materials, demonstrating the complete degradation of the network. We finally confirmed that the synthesized diepoxy compound is suitable for preparing carbon-fiber-reinforced composite materials, demonstrating easy fiber impregnation, fast reshaping, and especially a total degradation of the polymer matrix that allows for the recovery of the carbon fibers in mild conditions. This epoxy–amine system is an excellent candidate for overcoming the traditional limits of thermosets in preparing fiber-reinforced composites.

Design of blend-amine solid adsorbents for CO2 capture: Enhances adsorption- equilibrium cycle strategies and mechanism

Blend amine-functionalized absorbents show great potential in the field of amine scrubbing for CO2, as they harness the absorption benefits of various monomer amines in combination. However, there is a lack of research on the application of the emerging concept of blend amines to solid amine adsorbents. Building upon this foundation, this study firstly incorporated Aminoethylethanolamine (AEEA) into Polyethyleneimine (PEI) of varying molecular weights to create a range of new binary solid amine adsorbents. The research then compared the adsorption performance differences between these binary adsorbents and pure PEI adsorbents. The enhanced dispersion of PEI by AEEA results in an increase in the effective active sites available. The amine efficiency and CO2 adsorption capacity of the AEEA-PEI blend amine system were maximally increased by 92.0% and 84.6%, respectively, compared to the pure PEI system. Furthermore, through DFT calculations, it is clear that the presence of AEEA lowers the overall activation energy of the reaction due to its superior proton acceptance compared to PEI. However, the AEEA-PEI system exhibits weak cycling stability attributed to the limited regeneration capacity of AEEA. Fortunately, this issue can be successfully addressed by introducing a strong base, N,N,N',N'',N''-pentamethyl diethylenetriamine (PMDETA). The CO2 adsorption cycling stability for AEEA-PEI-PMDETA system maximally improved by up to 17.1% compared to the AEEA-PEI system. The mechanism behind the effectively suppression of cycling losses by PMDETA was further elucidated through DFT calculations. Consequently, the novel ternary amine solid adsorbent introduced in this study, aimed at enhancing the CO2 adsorption performance of monomer amine solid adsorbents, offers a fresh strategy for fundamental theoretical investigations into CO2 adsorption.

Low-Energy Electron Scattering from Ethyl Amine and Propyl Amine: A Comparative Study.

In this study, we investigate the low-energy electron (<20 eV) scattering cross sections for the linear ethyl amine and propyl amine using the R-matrix approach. A theoretical study is conducted, covering various cross sections such as elastic, symmetry-wise elastic, differential, momentum transfer, and electronic excitation. We obtained the ionization cross section using the CSP-ic and BEB methodologies. We unveil the intricate electron-amine interactions within these molecular systems. Additionally, our work extends to a comparative analysis among ethyl amine, propyl amine, and previously studied methyl amine systems. By comparing the obtained results, we discern subtle differences and similarities in the electron scattering behaviors across these structurally related amines. The findings presented herein shed light on fundamental electron-amine interactions, offering valuable insights for diverse fields ranging from chemical kinetics to astrophysics.

A general model for prediction of the CO2 equilibrium solubility in aqueous tertiary amine systems

AbstractWe have developed a general model to predict CO2 equilibrium solubility in aqueous tertiary amine solutions by relating the equilibrium constant (K1) to all relevant parameters in a logical function form. Testing our model, we measured CO2 equilibrium solubility data for N‐methylmorpholine (NMM) and N‐ethylmorpholine (NEM) across various conditions. Comparison with six existing models reveals our general model's superior predictive performance not only for NMM and NEM but also for an additional 10 tertiary amine solutions from literature, indicating its universality. Comprehensively considering the CO2 equilibrium solubility, amine dissociation constant (pKa) and the CO2 absorption heat, it is found that NMM and NEM may be promising desorption promoters enabling to reduce the energy cost. In short, it is expected the general model can be applied to more other tertiary amine systems.

Catalytic enantioselective intramolecular hydroamination of alkenes using chiral aprotic cyclic urea ligand on manganese (II)

Asymmetric catalysis for enantioselective intramolecular hydroamination of alkenes is a critical method in the construction of enantioenriched nitrogen-containing rings, often prevalent in biologically active compounds and natural products. Herein, we demonstrate a facile enantioselective intramolecular hydroamination of alkenes for the synthesis of chiral pyrrolidine, piperidine, and indoline moieties, using a manganese (II) chiral aprotic cyclic urea catalyst. The cyclic ligand hinders the inversion of the N atom of the urea and effectively discriminate between the enantiomers of substrates. High-resolution mass spectrometry, deuterium labeling experiments, and molecular orbital energy analysis clearly reveal the intermediates and mechanism of the transformation. As a key step, oxygen coordination by chiral aprotic urea presents a robust control over the asymmetric intra-HA reaction through the involvement of a convergent assembly of two vital intermediates (Mn-N and C-Mn-Br), providing access to chiral cyclic amine systems in high yields with excellent enantioselectivity.

A novel non-aqueous tertiary amine system for low energy CO2 capture developed via molecular dynamics simulation

The current technology for capturing CO2 using alkanolamine aqueous solutions is known for its high energy and capital costs. As a result, developing new absorbents for low-energy CO2 removal remains a challenge. An additional activator can promote CO2 absorption performance. However, it is based on experimental screening. In this study, based on molecular dynamic simulation, we have successfully developed a novel and energy-efficient CO2 absorbent by combining N, N-Dimethylethanolamine (DMEA), and ethylene glycol (EG), with different activators, including ethanolamine (MEA), ethylenediamine (EDA), and piperazine (PZ). The addition of these activators significantly enhances the CO2 absorption performance of DMEA-based absorbents. Among them, DMEA-PZ-EG exhibits the maximum CO2 absorption rate and capacity, achieving 6.35 (g-CO2/(kg-soln.·min.)) and 96.5 (g-CO2/kg-soln.), respectively, representing a 230.1 % and 206.35 % improvement over 2M DMEA-EG absorbent. Moreover, compared to a 30 wt% MEA solution, the energy consumption of DMEA-based absorbents is reduced by 33.93–51.56 %. The reaction products were characterized using various spectroscopic techniques, including Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR), and 1D and 2D Nuclear Magnetic Resonance spectroscopy (1H and 13C NMR). The NMR results confirmed that DMEA becomes protonated after CO2 absorption in the DMEA-EG mixture. The deprotonation of EG promote its reaction with CO2, resulting in the forming of EG carbonates. This assumption has been confirmed by the IR spectrum. Furthermore, the effect of activators on CO2 absorption has been analysed at the molecular level through molecular dynamics simulation and a new method is proposed to predict the CO2 absorption performance of non-aqueous solvents. Using non-aqueous DMEA absorbents presents a promising approach for improving CO2 capture efficiency, reducing energy consumption, and facilitating regeneration.

An energy-efficient cyclic amine system developed for carbon capture from both flue gas and air

High energy consumption is a major barrier to the large-scale deployment of carbon capture processes from flue gases or air (direct air capture, DAC). The non-aqueous amines reported in literature possess a high energy efficiency for CO2 capture from flue gases, they struggle with gas streams containing ultra-dilute CO2, like air, due to poor absorption kinetics. This study developed novel 2-PE (2-piperidineethanol)/APZ (Aminoethylpiperazine) based CO2 absorbents to address these problems. The experiments and MD simulation results showed that the 2-PE/APZ-based absorbents possessed a superior absorption performance both in flue gas and air. Among the developed absorbents, when 2-PE/APZ mixed with DMF (Dimethylformamide), the CO2 loading reached to 1.004 mol/mole, as the theoretical maximum. In DAC tests, 87.31 % CO2 from the air was captured in 24 h experiments. The regeneration heat duty of 2-PE/APZ/DMF decreased to 1.694 KJ/g CO2, a 55.89 % reduction compared to the benchmark 30 wt% MEA. The CO2 absorption/desorption mechanism was analysed by NMR, In-situ FT-IR, and DFT calculation. It indicated that this significant improvement in CO2 absorption performance and the reduction in energy consumption are due to the synergistic effect of 2-PE and APZ. During CO2 absorption, CO2 reacts with APZ forming APZ zwitterion rapidly, then deprotonation to the 2-PE. The formation of protonated 2-PEH+ ion pairs with APZCOO- reduces hydrogen bonds and van der Waals forces among the amine-CO2 complex, facilitating easy regeneration at mild conditions while maintaining high reactivity. The combination of theoretical and experimental results indicates that 2-PE/APZ-based absorbents can serve as a promising alternative for carbon capture from flue gas to air with low energy usage.

Low-energy electrochemical CO2-amine desorption driven by the proton-coupled electron transfer reaction (PCET)

The CO2 desorption in amine-based carbon capture processing is accompanied by significant energy consumption, accounting nearly 70% of energy requirements of the entire process. Electrochemical CO2 capture and release are promising technologies to reduce the energy consumption. The characteristics and CO2 desorption performance of QH2 (Tiron) in tertiary amine systems are investigated in this research. The reducing ability of Q (Oxidized QH2) was improved by modifying the electrode to achieve low-energy electrochemical desorption. The CO2 electrochemical desorption achieved low-energy CO2 desorption of 0.7 GJ ton−1 CO2 against over 2.4 GJ ton−1 in a conventional and mature MEA-based system.

Novel tri-solvent amines absorption for flue gas CO2 capture: Efficient absorption and regeneration with low energy consumption

Blended amine scrubbing is considered as a promising alternative to the monoamine scrubbing process due to the potential for enhanced CO2 capture efficiency and reduced energy consumption. However, striking a balance between absorption rate and regeneration energy consumption in blended amine systems by establishing suitable interactions between activated amines and proton-acceptor amines remains a significant challenge. In this study, a novel blended amine system, involving tertiary amine diethanolamine (DEEA) as the main agent and several monoamines as promoters, was first proposed to achieve highly effective CO2 capture. The designed tri-solvent amine system of DEEA combined with piperazine (PZ) and 4-amino-1-methylpiperidine (PD) (denoted as DEEA + PZ + PD) exhibited exceptional CO2 loading (0.988 mol CO2/mol amine), superior cyclic capacity (0.788 mol CO2/mol amine), and reduced regeneration heat duty (2.14 GJ/t), surpassing monoethanolamine (MEA) by 79.6 %, 277 %, and decreasing by 43.7 %, respectively. Furthermore, the performance improvement mechanism of DEEA + PZ + PD was systematically elucidated, showcasing the swift CO2 absorption facilitated by PD or PZ in the initial reaction phase, and the subsequent formation of bicarbonate from PDCOO− and DEEA in the later stage, enhancing CO2 absorption capacity. The predominant reaction products, bicarbonate and unstable carbamate (PZ(COO−)2, PDCOO−), contribute to the high regeneration efficiency and minimal energy consumption during regeneration for DEEA + PZ + PD. Consequently, this facilely prepared tri-solvent amine system, characterized by high capture efficiency and low energy consumption, holds promise for achieving carbon–neutral operations in coal-fired power plants.

Cerium-MOF-Derived Composite Hierarchical Catalyst Enables Energy-Efficient and Green Amine Regeneration for CO2 Capture.

The excessive energy consumed restricts the application of traditional postcombustion CO2 capture technology and limits the achievement of carbon-neutrality goals. Catalytic-rich CO2 amine regeneration has the potential to accelerate proton transfer and increase the energy efficiency in the CO2 separation process. Herein, we reported a Ce-metal-organic framework (MOF)-derived composite catalyst named HZ-Ni@UiO-66 with a hierarchical structure, which can increase the CO2 desorbed amount by 57.7% and decrease the relative heat duty by 36.5% in comparison with the noncatalytic monoethanolamine (MEA) regeneration process. The composite catalyst of the CeO2 coating from the UiO-66 precursor on the HZ-Ni carrier shows excellent stability with a long lifespan. The HZ-Ni@UiO-66 catalyst also shows a universal catalytic effect in typical blended amine systems with a large cyclic capacity. The HZ-Ni@UiO-66 catalyst effectively decreases the energy barrier of the CO2 desorption reaction to reduce the time required to reach thermodynamics, consequently saving the energy consumption generated by water evaporation. This research provides a new avenue for advancing amine regeneration with less heat duty at low temperatures.

Intramolecular hybrid diamine DMAPA/n-PeOH/H2O biphasic absorbent for CO2 absorption through combining zwitterion and base-catalyzed hydration mechanism

Biphasic solvents can decrease the regeneration energy of CO2 capture. As an intramolecular hybrid diamine, 3-Dimethylaminopropylamine (DMAPA) had a primary amino group and a tertiary amino group, which could absorb CO2 by combining zwitterion and base-catalyzed hydration mechanism. The derived DMAPA/n-PeOH/H2O biphasic absorbent possessed high CO2 absorption capacity (1.46 mol/mol) and large CO2-rich phase loading (6.27 mol/L), which were superior to existing mixed amine systems. At 393.15 K, this system had a large desorption amount of 4.91 mol/L and a fast desorption rate (6.68 E-3 mol/L·s), which were 2.84 and 3.73 times of 30 wt% MEA. The associated total regeneration energy was reduced to 1.36 GJ/t CO2, only 34.1 % of MEA absorbent. The reaction mechanism and origin of phase separation were revealed by NMR analysis and quantum chemistry calculations. In addition, low viscosity and corrosiveness were revealed and conducive for industrial application.

Surface properties of systems based on amines and (co)polymers of acrylamide at the liquid–air interface

Surface properties of the systems based on amines and acrylamide (co)polymers have been studied depending on the molecular structure of the components in aqueous and saline (sodium chloride) solutions. For the systems of amines with an anionic acrylamide copolymer, a change in the shape of the surface tension isotherm was found. The tendency to change the surface properties is enhanced in systems with an anionic acrylamide copolymer, aliphatic amine and in the presence of a low molecular weight electrolyte.

Analysis of Natural Antibodies during the Development of Phantom Pain Syndrome.

We determined natural antibodies (n-Abs) to the regulators of the main systems of biochemical homeostasis: β-endorphin, serotonin, dopamine, histamine, orphanin, angiotensin, GABA, glutamate, bradykinin, vasopressin, thrombin, and α-2-macroglobulin in individuals with phantom pain syndrome (PPS), resulting from amputation after injury. It was established that each patient has an individual immunoprofile, but for all of them there was a significant increase in the level of antibodies to serotonin, histamine, and angiotensin, which reflect the chronicity of the pain syndrome and do not depend on the self-assessment of the severity of PPS. Determination of the role of regulators of biochemical homeostasis in the development of phantom pain showed that, at high, moderate, and weak severity of PPS, the biogenic amine and angiotensinergic systems are activated. A decrease in PPS intensity normalizes deviations in all immunological parameters. The levels of n-Abs for the pain (β-endorphin) and analgesic (orphanin) systems are significant only at low PPS. Monitoring the individual profile of n-Abs to endogenous regulators allows us to obtain an objective picture of the pain status of the patient's body.

Hybrid behaviors of CO2 absorption into blended DEEA‐based solution for the improvement of capture performance

AbstractBACKGROUNDAt present, the chemical absorption method of CO2 capture is considered to be an effective means to reduce carbon emissions. The development of blended amine systems with excellent CO2 capture performance is the focus of research.RESULTThe hybrid behaviors of N,N‐diethylethanolamine (DEEA) with addition of monoethanolamine (MEA), 2‐(methylamino)ethanol(MAE) and 2‐((2‐aminoethyl)amino)‐ethanol(AEEA) as absorbents were investigated and developed to reduce the energy consumption for solvent regeneration in the CO2 capture process. The equilibrium solubility of CO2 for blended DEEA/MEA, DEEA/MAE and DEEA/AEEA with a series of molar ratios (0.0:2.0, 0.5:1.5, 1.0:1.0, 1.5:0.5 and 2.0:0.0) was examined. The experimental results showed that the values of CO2 equilibrium solubility of amine blends exhibited a compromise behavior between each individual amine solution. Additionally, the effects of molar ratios on the relative CO2 absorption rate, regeneration rate and CO2 cyclic capacity for the tested amine blends were studied using an improved rapid absorbent screening method.CONCLUSIONThe experimental data showed that the blended DEEA/MAE solution exhibits much higher CO2 cyclic capacity than that of DEEA/AEEA under the nitrogen atomic conservation. However, the mixing DEEA and AEEA could obviously reduce the CO2 equilibrium solubility and CO2 cyclic capacity compared with that of individual AEEA solution, indicating the DEEA had an inhibiting effect on AEEA. Furthermore, the mass transfer performances of DEEA, DEEA/MAE and DEEA/AEEA were tested in order to validate the accuracy of the improved rapid absorbent screening method. © 2024 Society of Chemical Industry (SCI).

Evaluating solvent efficiency for carbon capture: Comparative analysis of temperature, concentration and diffusivity effects

In the pursuit of efficient carbon capture technologies, the selection and design of solvents play a pivotal role, directly impacting various crucial factors such as CO2 absorption capacity, equipment size, and regeneration energy requirements. The primary focus is on optimizing solvent systems through a comprehensive analysis of intermolecular interaction intensity, diffusion coefficient, and intra-molecular interaction intensity. This study employs a molecular dynamics simulation model to identify the most suitable solvent system by assessing the effect of operating variables like temperature, concentration, interaction intensity, and diffusivity of various single and blended amine systems. The assessment utilizes the radial distribution function and mean square displacement analysis. The results indicate that intermolecular interactions with CO2 are most significant in 30 wt% 2EAE, 40 wt% 2DMAE and 10% DMCA with 20% MCA ratio concentrations. TMPAD, in particular, stands out for its high repulsive interaction and low energy requirement for breaking the carbamate/bicarbonate ion. Diffusion behavior in various observed solvent systems is as follows: EAE > MEA > DMAE > MAE-DEAB > MAE-DMA2P > EAE-TMPAD > AMP-PZ > EAE-DEAB > MAE-TMPAD > EAE-DMA2P > MAE-DMAE > EAE-DMAE > TMPAD > MEA-AMP > DMA2P > DMCA-MCA > DEAB > MEA-PZ. Moreover, elevated temperatures facilitate enhanced diffusivity, leading to accelerated mass transfer rates. This implies the possibility of reducing the size of absorber units and lowering energy consumption. Further studies on heat of absorption and kinetic characteristics of solvent blends are necessary to ensure their practical applicability in carbon capture and industrial operations.

Trace Amine-Associated Receptors' Role in Immune System Functions.

Trace amines are a separate, independent group of biogenic amines, close in structure to classical monoamine neurotransmitters such as dopamine, serotonin, and norepinephrine that include many products of the endogenous or bacteria-mediated decarboxylation of amino acids. A family of G protein-coupled trace amine-associated receptors (in humans, TAAR1, TAAR2, TAAR5, TAAR6, TAAR8, and TAAR9) that senses trace amines was discovered relatively recently. They are mostly investigated for their involvement in the olfaction of volatile amines encoding innate behaviors and their potential contribution to the pathogenesis of neuropsychiatric disorders, but the expression of the TAAR family of receptors is also observed in various populations of cells in the immune system. This review is focused on the basic information of the interaction of trace amines and their receptors with cells of the general immune systems of humans and other mammals. We also overview the available data on TAARs' role in the function of individual populations of myeloid and lymphoid cells. With further research on the regulatory role of the trace amine system in immune functions and on uncovering the contribution of these processes to the pathogenesis of the immune response, a significant advance in the field could be expected. Furthermore, the determination of the molecular mechanisms of TAARs' involvement in immune system regulation and the further investigation of their potential chemotactic role could bring about the development of new approaches for the treatment of disorders related to immune system dysfunctions.

Hybrid Siloxane Materials Based on a Mutually Reactive Epoxy–Amine System: Synthesis, Structure, and Thermal Stability Investigations

Hybrid siloxane materials based on a mutually reactive epoxy–amine system are organic-inorganic hybrid materials synthesized via the sol–gel reaction of siloxane precursors, followed by the polymerization of organo-functionalized oligosiloxanes. Therefore, using a new hybrid system as the reaction product resulting from the reaction between 1,3-bis(3-glycidoxypropyl)-l, 1,3,3-tetramethyldisiloxane—C16H34O5Si2—(gp-DS) and p-phenylenediamine—C6H4(NH2)2—(PPD), an aromatic diamine, was obtained. The chemical structure of the synthesized hybrid siloxane material was confirmed via Fourier Transform Infra-Red (FTIR) spectroscopy, mass spectrometry (MS), and 1H-NMR spectroscopy. The morphology and surface chemical composition was highlighted via scanning electron microscopy (SEM) equipped with an EDX elemental analysis system. Further, the thermal stabilities of the prepared hybrid siloxane and its precursors have been investigated via thermogravimetric analysis (TGA), proving the modification of epoxy-functional disiloxanes with a paraphenylenediamine reagent that made it possible to produce hybrid siloxane materials with very good thermal stabilities and dual weak hydrophilic/hydrophobic surfaces.

Zero-Emission Cement Plants with Advanced Amine-Based CO2 Capture.

Decarbonization of the cement sector is essentially required to achieve carbon neutrality to combat climate change. Amine-based CO2 capture is a leading and practical technology to deeply remove CO2 from the cement industry, owing to its high retrofittability to existing cement plants and extensive engineering experience in industrial flue gas decarbonization. While research efforts have been made to achieve low-carbon cement with 90% CO2 removal, a net-zero-emission cement plant that will be required for a carbon neutrality society has not yet been investigated. The present study proposed an advanced amine-based CO2 capture system integrated with a cement plant to achieve net-zero CO2 emission by pushing the CO2 capture efficiency to 99.7%. Monoethanomaine (MEA) and piperazine/2-amino-2-methyl-1-propanol (PZ-AMP) amine systems, which are considered to be the first- and second-generation capture agents, respectively, were detailed investigated to deeply decarbonize the cement plant. Compared to MEA, the advanced PZ-AMP system exhibited excellent energy performance with a regeneration duty of ∼2.6 GJ/tonne CO2 at 99.7% capture, 39% lower than the MEA process. This enabled a low CO2 avoided cost of $72.0/tonne CO2, which was 18% lower than that of the MEA-based zero-emission process and even 16.2% lower than the standard 90% MEA process. Sensitivity analysis revealed that the zero-emission capture cost of the PZ-AMP system would be further reduced to below $56/tonne CO2 at a $4/GJ steam production cost, indicating its economic competitiveness among various CO2 capture technologies to achieve a zero-emission cement plant.