Synthesis of zeolitic material from basalt rock and its adsorption properties for carbon dioxide

Improving the efficiency of 4A-zeolite synthesized from kaolin by amine functionalization for CO2 capture

This study focuses on optimizing the CO2 adsorption capacity of 4A-zeolite synthesized from kaolin by employing structural modifications through impregnation with tetraethylenepentamine (TEPA) and diethanolamine (DEA). Various analytical techniques were utilized to evaluate the effectiveness of these modifications. Design expert software and response surface methodology (RSM) was employed for data analysis and operational variable optimization, leading to improved CO2 adsorption performance of the modified zeolites. The adsorption capacity of the modified zeolites was assessed under different temperatures, pressures, and amine concentrations using a test device. The optimal adsorption capacity of 4A-DEA adsorbent is found to be 579.468 mg/g, with the optimal operational variables including a temperature of 25.270 °C, pressure of 8.870 bar, and amine concentration of 11.112 wt%. The analysis shows that the adsorption process involves both physisorption and chemisorption, and the best kinetic model is the fractional-factor model.

Carbon Capture Materials in Post-Combustion: Adsorption and Absorption-Based Processes

Global warming and climate changes are among the biggest modern-day environmental problems, the main factor causing these problems is the greenhouse gas effect. The increased concentration of carbon dioxide in the atmosphere resulted in capturing increased amounts of reflected sunlight, causing serious acute and chronic environmental problems. The concentration of carbon dioxide in the atmosphere reached 421 ppm in 2022 as compared to 280 in the 1800s, this increase is attributed to the increased carbon dioxide emissions from the industrial revolution. The release of carbon dioxide into the atmosphere can be minimized by practicing carbon capture utilization and storage methods. Carbon capture utilization and storage (CCUS) has four major methods, namely, pre-combustion, post-combustion, oxyfuel combustion, and direct air capture. It has been reported that applying CCUS can capture up to 95% of the produced carbon dioxide in running power plants. However, a reported cost penalty and efficiency decrease hinder the wide applicability of CCUS. Advancements in the CCSU were made in increasing the efficiency and decreasing the cost of the sorbents. In this review, we highlight the recent developments in utilizing both physical and chemical sorbents to capture carbon. This includes amine-based sorbents, blended absorbents, ionic liquids, metal-organic framework (MOF) adsorbents, zeolites, mesoporous silica materials, alkali-metal adsorbents, carbonaceous materials, and metal oxide/metal oxide-based materials. In addition, a comparison between recently proposed kinetic and thermodynamic models was also introduced. It was concluded from the published studies that amine-based sorbents are considered assuperior carbon-capturing materials, which is attributed to their high stability, multifunctionality, rapid capture, and ability to achieve large sorption capacities. However, more work must be done to reduce their cost as it can be regarded as their main drawback.

The Adsorptive and Photocatalytic Performance of Granite and Basalt Waste in the Discoloration of Basic Dye

The present work explored the adsorptive capacity and catalytic activity of rock powders from basaltic and granitic rocks in the discoloration of synthetic and industrial effluents containing the yellow dye Basic Yellow 96. The rock powders were characterized with scanning electron microscopy associated with energy-dispersive spectroscopy, photoacoustic spectroscopy, N2 physisorption and X-ray diffraction, the latter confirming the abundant presence of silica in the four materials studied. The basaltic powders presented specific surface areas between 7 and 10 times greater than those of granitic materials, which allowed up to 92% removal of the dye in 3 h of test using the basaltic powder. Despite the smaller area, the granitic materials showed considerable photocatalytic activity in 3 h, 94%, the same as that of the basaltic materials in the photocatalysis. Granitic and basaltic photocatalysts proved to be efficient in the discoloration of synthetic and industrial effluents, although TOC analyses indicated that it was not possible to promote the pollutant mineralization in the industrial effluent. Both artificial light and sunlight were effective in the photocatalysis of the dye, although the former was slightly faster.

Influence of ultra-micropore volume of activated carbons prepared from noble mung bean on the adsorption properties of CO2, CH4, and N2

In this study, mung bean-based nanoporous activated carbons with different pore properties were prepared by varying the mass ratio of activating agent (KOH) and activation temperature.

Synthesis of Zeolite 4A from Kaolin and Its Adsorption Equilibrium of Carbon Dioxide

Zeolite 4A was successfully prepared by hydrothermal synthesis using low-grade kaolin as a raw material. The properties of the synthesized zeolite 4A were characterized by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR), 29Si magic-angle spinning (MAS)-nuclear magnetic resonance (NMR) and 27Al MAS-NMR, X-ray fluorescence (XRF), scanning electron microscopy (SEM)-energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), thermogravimetry (TG)-differential thermal analysis (DTA), and carbon dioxide adsorption analysis. The textural properties of the synthesized zeolite 4A was further studied by BET analysis technique. The thermal stability analysis showed that the heat resistance of the synthesized zeolite 4A is up to 940 °C. In addition, it is found that the Langmuir model has the best agreement with the adsorption equilibrium data for carbon dioxide by synthesized zeolite 4A and commercial zeolite 4A. Meanwhile, the carbon dioxide adsorption analysis confirmed that the maximum equilibrium adsorption amount of carbon dioxide on synthesized zeolite 4A is 59.3820 mL/g, which is higher than the 55.4303 mL/g of the commercial zeolite 4A.