Passive Direct Air Capture of Carbon Dioxide with an Alkaline Amino Acid Salt in Water-Based Paints

The current study presents the first results of the passive capture of carbon dioxide from the air in aqueous sodium lysinate solutions at ambient conditions. The salt has shown good passive direct air capture (DAC) properties for carbon dioxide with spent solutions exhibiting more than 5% carbon dioxide by weight. Moreover, different quantities of sodium lysinate solutions were mixed with three commercial water-based paints, and their passive DAC performance was studied for 45 days. An average improvement of 70% in passive DAC capacity compared to the control sample was observed across all the studied paint samples. The results establish that a litre of water-based paint doped with sodium lysinate can absorb up to 40 g of CO 2 and fix it stably for a short period of time, i.e., 45 days. Such paints can be used to directly capture carbon dioxide from the air. However, further research is required to address various technicalities and establish long-term sequestration.</p

Interfacial Tailoring of Polyether Sulfone-Modified Silica Mixed Matrix Membranes for CO2 Separation

In this work, in situ polymerization of modified sol-gel silica in a polyether sulfone matrix is presented to control the interfacial defects in organic-inorganic composite membranes. Polyether sulfone polymer and modified silica are used as organic and inorganic components of mixed matrix membranes (MMM). The membranes were prepared with different loadings (2, 4, 6, and 8 wt.%) of modified and unmodified silica. The synthesized membranes were characterized using Field emission electron scanning microscopy, energy dispersive X-ray, Fourier transform infrared spectroscopy, thermogravimetric analyzer, and differential scanning calorimetry. The performance of the membranes was evaluated using a permeation cell set up at a relatively higher-pressure range (5–30 bar). The membranes appear to display ideal morphology with uniform distribution of particles, defect-free structure, and absence of interfacial defects such as voids and particle accumulations. Additionally, the CO(2)/CH(4) selectivity of the membrane increased with the increase in the modified silica content. Further comparison of the performance indicates that PES/modified silica MMMs show a promising feature of commercially attractive membranes. Therefore, tailoring the interfacial morphology of the membrane results in enhanced properties and improved CO(2) separation performance

Quantitative Estimation of Biocapped Surface Chemistry Driven Interparticle Interactions and Growth Kinetics of Gold Nanoparticles

In phytosynthesis of gold nanoparticles (AuNPs), biomolecules play a vital role in biocapping the surface of particles and generating the electrostatic repulsive forces to inhibit their growth kinetics. However, estimation of bioactive compounds influencing their surface characteristics through formation of electric repulsive forces (Velec\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$V_{elec}$$\end{document}), Van der Waals attraction forces (Vvdw\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$V_{vdw}$$\end{document}) and ultimately hindering their growth is still in the phase of obscurity. Current study, based on surface chemistry approach has been performed for identification of bioactive compounds in Elaeis guineensis leaves (EGL/OPL), acting as biocapping agents and directing the growth of AuNPs over a period of time. The quantitative estimation of interparticle interactions and modification in Ostwald ripening (MOR) model were also done to correlate the growth kinetic of AuNPs. The X-ray photoelectron spectroscopy (XPS) showed the major contribution of oxygen, carbon and nitrogen elements, corresponding to polyphenolic, carboxylic and amides, in biocapping the surface of AuNPs and directing their interparticle interactions associated with growth kinetics. The Velec\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$V_{elec}$$\end{document} forces were reduced with an enhancement in the Vvdw\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$V_{vdw}$$\end{document} forces, depicting their major role in impeding growth of AuNPs. The MOR model exhibited an excellent agreement of predicted growth with experimental size enlargements of AuNPs, having 4.8% average absolute relative percentage error

Ultrasonic-Assisted Extraction of Toxic Acidic Components from Acidic Oil Using 1,8-Diazobicyclo[5.4.0]undec-7-ene-Based Ionic Liquids

[Image: see text] Ionic liquids (ILs) show remarkable performance in enhancing the naphthenic acid extraction efficiency and decreasing the extraction time. However, the ultrasonic-assisted IL-based extraction of naphthenic acid is merely addressed previously. Therefore, this study investigated the impact of essential ultrasonic parameters, including amplitude and time, on naphthenic acid extraction using different ILs, and the system was optimized for maximum extraction. The IL 1,8-diazobicyclo[5.4.0]-undec-7-ene (DBU) with thiocyanate anions revealed the highest efficiency in extracting naphthenic acid from a model oil (dodecane) at optimized conditions, and the experimental liquid–liquid equilibrium data were obtained at atmospheric pressure for the mixture of dodecane, [DBU], thiocyanate, and naphthenic acid. In addition, the influence of the chain length of the cation (hexyl, octyl, or decyl) on the extraction efficiency was also evaluated by determining the distribution coefficients, and the conductor-like screening model for real solvents (COSMO-RS) study was carried out at infinite dilution. It was found that [DBU-Dec] [SCN] gives the best extraction efficiency and has a distribution coefficient of 9.2707 and a performance index of 49.48. Based on these values, ILs can be ordered as follows: [DBU-Dec] [SCN] > [DBU-Oct][SCN] > [DBU-Hex][SCN] in the decreasing order of performance index 49.48, 41.58, and 28.13. Moreover, non-random two liquid and Margules thermodynamic models were employed to investigate the interaction parameters between the components. Both models showed excellent agreement with the experimental results and could successfully be used for ultrasonic-assisted IL extraction of naphthenic acid

Optimizing the Air Conditioning Layouts of an Indoor Built Environment:Towards the Energy and Environmental Benefits of a Clean Room

Reducing energy consumption in buildings has received intensified research impetus since the introduction of the decarbonization goals set in the Paris agreement. Many domestic and specialized applications require clean rooms (indoor built environments) for safe and clean operation. Energy efficiency in clean room spaces depends on maintaining livable or required conditions such as temperature, humidity, and particle concentration with minimal use of energy and new carbon dioxide (CO2) emissions. In the literature, parameters such as temperature, relative humidity, particle concentrations, and CO2 emissions are not able to be properly controlled in clean room systems. The designed system in the literature involves high energy consumption and high economic costs. All these factors add novelty to this research, which was a significant research gap in previous studies. This clean room is directly linked to environmental parameters such as ambient temperature, relative humidity, etc. The clean room is also related directly to the building and infrastructure in such a way that there are certain regulatory requirements for designing a clean room. For designing and constructing the controlled environment in a clean room, the English (EN) documents, ISO 9000, and various other standards allow for clean rooms for different types of products. In this research, the designed control configurations properly control the system. Additionally, this system is energy efficient, with positive environmental aspects regarding CO2 emissions. Three control configurations were designed in this research, option A, option B, and option C, and three parameters are controlled in the study. These parameters are room temperature, relative humidity, and CO2 emissions (outside the room). CO2 emissions are controlled outside the room (in the environment). In the last research phase, a comparative analysis of these three control configurations was performed to find an energy-efficient system with fewer CO2 emissions. Control configuration B (option B) provides reliable results regarding an energy-efficient system and fewer CO2 emissions emitted to the environment. In this study, an optimized configuration for the air conditioning system was developed for a clean room (volume 185.6 m3) with a required temperature of 23 °C, relative humidity of 40%, and a particle size of less than 0.3 μm. Three different design configurations were analyzed using TRNSYS simulation software. The minimization of energy use and CO2 emissions were the objective functions. Energy loads were calculated for each of the configurations by varying the fixed air change per hour and the minimum outdoor air flow rate. The results of a whole year simulation run for control configurations A, B, and show that, on the one hand, the ambient weather conditions of temperature and relative humidity (RH) is varied throughout year and, on the other hand, the clean room temperature was maintain at exactly 23 °C, which is the required set point temperature, for all the three configurations (A, B, and C). Furthermore, the clean room relative humidity was maintained at 36% for configuration A, below the 40% which was the set point for clean room relative humidity, and at 40% for configurations B and C. Configuration B exhibited the minimum energy use (7300 kWh), at a fixed air change per hour value of 20 and a minimum outdoor air flow rate of 150 L/s, with the least amount of CO2 emissions, offering an overall 25% improvement over configurations A and C

ENHANCED SEMI-EMPIRICAL THERMODYNAMIC MODEL FOR CARBON DIOXIDE SOLUBILITY IN AQUEOUS ALKANOLAMINES

Phase equilibrium studies play a pivotal role in equipment design, system integration and process development by establishing process boundaries and operational scope of a chemical system. Most of experimental studies are not expansible to industrial environments due to their highly nonlinear nature and carbon dioxide-alkanolamine-water system is no exception. Hence, a thermodynamic approach is mandatory to correlate the process variables with good concocti~m of simplicity, accuracy and efficiency