An intelligent system for monitoring and diagnosis of the CO2 capture process

Amine-based carbon dioxide capture has been widely considered as a feasible ideal technology for reducing large-scale CO₂ emissions and mitigating global warming. The operation of amine-based CO₂ capture is a complicated task, which involves monitoring over 100 process parameters and careful manipulation of numerous valves and pumps. The current research in the field of CO₂ capture has emphasized the need for improving CO₂ capture efficiency and enhancing plant performance. In the present study, artificial intelligence techniques were applied for developing a knowledge-based expert system that aims at effectively monitoring and controlling the CO₂ capture process and thereby enhancing CO₂ capture efficiency. In developing the system, the inferential modeling technique (IMT) was applied to analyze the domain knowledge and problem-solving techniques, and a knowledge base was developed on DeltaV Simulate.The expert system helps to enhance CO₂ capture system performance and efficiency by reducing the time required for diagnosis and problem solving if abnormal conditions occur. The expert system can be used as a decision-support tool that helps inexperienced operators control the plant; it can be used also for training novice operators.     

Experimental study on the solvent regeneration of a CO2‐loaded MEA solution using single and hybrid solid acid catalysts

The performance of a hybrid solid acid catalyst consisting of a physical mixture of γ‐Al₂O₃ and H‐ZSM‐5 in terms of the rate and heat duty for solvent regeneration (i.e., CO₂ stripping) of a CO₂‐rich MEA solution was compared with the individual performance of γ‐Al₂O₃, H‐ZSM‐5, and H‐Y solid acid catalysts using MEA (2–7 mol/L), with initial CO₂ loading of 0.5 mol CO₂/mol MEA at 378 K. It was observed that any catalyst significantly decreased the energy required for CO₂ regeneration. The performance of the catalysts investigated ranked as follows: γ‐Al₂O₃/H‐ZSM‐5 = 2/1 > γ‐Al₂O₃ > H‐ZSM‐5 > H‐Y if the process is in the lean CO₂ loading region whereas it was H‐ZSM‐5 > γ‐Al₂O₃/H‐ZSM‐5 = 2/1 > γ‐Al₂O₃ > H‐Y if the process is in the rich CO₂ loading region. These results highlight the joint dependence on Brønsted/Lewis acidity and mesopore surface area of heat duty for solvent regeneration. © 2015 American Institute of Chemical Engineers AIChE J, 62: 753–765, 2016     

Investigation mechanism of DEA as an activator on aqueous MEA solution for postcombustion CO2 capture

In this work, Diethanolamine (DEA) was considered as an activator to enhance the CO₂ capture performance of Monoethanolamine (MEA). The addition of DEA into MEA system was expected to improve disadvantages of MEA on regeneration heat, degradation, and corrosivity. To understand the reaction mechanism of blended MEA‐DEA solvent and CO₂, ¹³C nuclear magnetic resonance (NMR) technique was used to study the ions (MEACOO^‐, DEACOO^–, MEA, DEA, MEAH⁺, DEAH⁺, , ) speciation in the blended MEA‐DEA‐CO₂‐H₂O systems with CO₂ loading range from 0 to 0.7 mol CO₂/mol amine at the temperature of 301 K. The different ratios of MEA and DEA (MEA: DEA = 2.0:0, 1.5:0.5, 1.0:1.0, and 0:2.0) were studied to comprehensively investigate the role of DEA in the system of MEA‐DEA‐CO₂‐H₂O. The results revealed that DEA performs the coordinative role at the low CO₂ loading and the competitive role at high CO₂ loading. Additionally, the mechanism was also proposed to interpret the reaction process of the blended solvent with CO₂. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2515–2525, 2018     

The design of linear and circular polarization for dual band microstrip slot antenna

This paper presents a lightweight antenna for wireless communication systems. The proposed antenna has been designed to be a dual‐band and dual‐polarized antenna by using a right‐angled slot structure fed a by microstrip line. The designed antenna is composed of three right‐angled slot radiators on the ground plane. The first two radiators are right‐angled slots of similar scale which are added to generate circular polarization at 4.95 GHz, while the last one has been designed for linear polarization at 2.45 GHz. Furthermore, in order to achieve dual‐band operation and dual polarization with good matching, a special arrangement is proposed. The results of simulation and measurements such as return loss, axial ratio, and radiation patterns are shown at the resonant frequencies of 2.45 and 4.95 GHz. Details of the experimental results are presented and discussed. In addition, the presented antenna can operate and cover the applications of a wireless local area network (WLAN IEEE 802.11 a/b/g/j/n). © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Solubilities of Carbon Dioxide in Polyethylene Glycol Ethers

New extensive data are reported for the solubility of carbon dioxide in fourteen physical solvents, and compared to two other solvents widely used in industry (selexol® and sulfolane). The solubility data are expressed by Henry's law constants and have been measured at 25 °C, 40 °C and 60 °C, using an Autoclave cell. The study concludes that polyethylene glycol dimethyl ethers, and mixtures of these solvents are the best solvents for CO₂ removal.     

A new model for correlation and prediction of equilibrium CO2 solubility in N‐methyl‐4‐piperidinol solvent

In this work, the equilibrium CO₂ solubility in the aqueous tertiary amine, N‐methyl‐4‐piperidinol (MPDL) was measured over a range of temperatures, CO₂ partial pressures and amine concentrations. The dissociation constant of the MPDL solution was determined as well. A new thermodynamic model was developed to predict the equilibrium CO₂ solubility in the MPDL‐H₂O‐CO₂ system. This model, equipped with the correction factor (C_f), can give reasonable prediction with an average absolute deviation of 2.0%, and performs better than other models (i.e., KE model, Li‐Shen model, and Hu‐Chakma). The second‐order reaction rate constant (k₂) of MPDL and the heat of CO₂ absorption (–ΔH_abs) into aqueous MPDL solutions were evaluated as well. Based on the comparison with some conventional amines, MPDL revealed a high‐equilibrium CO₂ loading, reasonably fast absorption rate when compared with other tertiary amines, and a low energy requirement for regeneration. It may, therefore, be considered to be an alternative solvent for CO₂ capture. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3395–3403, 2017     

Bu4NBr/Mg（OH）Cl高效催化二氧化碳和环氧丙烷合成碳酸丙烯酯

考察了几种均相、非均相和负载型催化剂对CO2和环氧丙烷(PO)合成碳酸丙烯酯(PC)的催化性能的影响,发现n-Bu4NBr/Mg(OH)Cl具有较高的催化活性。在不加任何溶剂的条件下,研究其对反应的影响。催化剂n-Bu4NBr/Mg(OH)Cl重复使用6次后,催化活性略微下降。     

SO42−/ZrO2 supported on γ‐Al2O3 as a catalyst for CO2 desorption from CO2‐loaded monoethanolamine solutions

In this work, the composite catalysts, SO₄²/ZrO₂/γ‐Al₂O₃ (SZA), with different ZrO₂ and γ‐Al₂O₃ mass ratios were prepared and used for the first time for the carbon dioxide (CO₂)‐loaded monoethanolamine (MEA) solvent regeneration process to reduce the heat duty. The regeneration characteristics with five catalysts (three SZA catalysts and two parent catalysts) of a 5 M MEA solution with an initial CO₂ loading of 0.5 mol CO₂/mol amine at 98°C were investigated in terms of CO₂ desorption performance and compared with those of a blank test. All the catalysts were characterized using X‐ray diffraction, Fourier transform infrared spectroscopy, N₂ adsorption–desorption experiment, ammonia temperature programmed desorption, and pyridine‐adsorption infrared spectroscopy. The results indicate that the SZA catalysts exhibited superior catalytic activity to the parent catalysts. A possible catalytic mechanism for the CO₂ desorption process over SZA catalyst was proposed. The results reveal that SZA1/1, which possesses the highest joint value of Brφnsted acid sites (BASs) and mesopore surface area (MSA), presented the highest catalytic performance, decreasing the heat duty by 36.9% as compared to the catalyst‐free run. The SZA1/1 catalyst shows the best catalytic performance as compared with the reported catalyst for this purpose. Moreover, the SZA catalyst has advantages of low cost, good cyclic stability, easy regeneration and has no effect on the CO₂ absorption performance of MEA. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3988–4001, 2018     

Kinetics and Reactor Modeling of the Steam Reforming of Methanol over a Mn‐Promoted Cu/Al Catalyst

The kinetics of the steam reforming of methanol (SRM) was studied in a packed‐bed reactor over a Mn‐promoted Cu/Al₂O₃ catalyst under defined conditions. A Langmuir‐Hinshelwood‐Hogan‐Watson (LHHW)‐type mechanism that assumes the dissociative adsorption of methanol on two distinct active sites as the rate‐controlling step was found to satisfactorily describe the SRM reaction with activation energies of 77.3 and 64.5 kJ mol^?1 at low and high temperature, respectively. No mass or heat transfer limitations were observed under the experimental conditions used in this study. A reactor model was also developed, validated, and employed to predict the conversion, temperature, and concentration profiles. The axial dispersion had no influence on the temperature distribution but the effect was more pronounced on the methanol conversion.