Synthesis Of Sorbents Research Articles

The Carbon Challenge: Design, Synthesis, and Chemisorption Behavior of Solid Sorbents in Direct Air Capture of Carbon Dioxide

The Carbon Challenge: Design, Synthesis, and Chemisorption Behavior of Solid Sorbents in Direct Air Capture of Carbon Dioxide

A porous phenolic resin sorbent for enhanced CO2 capture: Synthesis, optimization, and techno-economic analysis

Amidst rising global concerns about climate change, the capture and sequestration of carbon dioxide (CO2) from industrial emissions is becoming increasingly critical. In the present study, a phenolic resin-based porous polymer for CO2 capture is developed, offering a solution to the dual challenges of efficacy and cost in current carbon capture technologies. Optimization of synthesis parameters, including temperature, reaction time, and catalyst amount was performed using response surface methodology (RSM) to maximize surface area and economic benefits. The optimized polymer demonstrated a substantial CO2 adsorption capacity of 3.06 mmol/g at 273 K and 1 bar, with a specific surface area of 860 m2/g. An early-stage techno-economic analysis of sorbent synthesis was conducted, relating cost to sorbent quality and surface area. It was found that producing the polymer at low temperatures is more cost-effective, while synthesis at higher temperatures offers operational advantages. This research addresses a gap in existing literature by focusing on the sorbent material and its economic viability, paving the way toward the commercialization of such adsorption technology.

H2S induced in-situ formation of recyclable metal sulfide-based sorbent for elemental mercury sequestration in natural gas

Enlightened by the phenomenon that hydrogen sulfide (H2S) can readily decompose on metal oxides to generate sulfide species and the obtained metal sulfides are generally adopted as Hg-affine ligands for Hg0 capture, a urea modified copper oxide (U-CuO) was prepared via high-temperature calcination of the mixture of urea and copper nitrate for Hg0 removal in natural gas containing H2S. Benefitted from the decomposition of urea and the release of gaseous decomposition products, the as-synthesized U-CuO was enriched with abundant base sites and lattice oxygen, and characterized with developed textural features, which facilitates the diffusion and adsorption of H2S and subsequent sequestration of Hg0. The Hg0 adsorption capacity and uptake rate of U-CuO under simulated natural gas (N2 + 500 ppm H2S+8% H2O) reached as high as 134.06 mg g−1 and 58.32 μg g−1 min−1, respectively, which largely surpassed those of most CuS-based sorbents for Hg0 immobilization. Besides, U-CuO sorbent also exhibited satisfactory recyclability only through simple thermal treatment, the Hg0 removal efficiency of U-CuO maintained above 97 % even after ten adsorption-regeneration rounds. This preparation strategy not only provides valuable hints to guide the design and synthesis of Hg0 sorbents used for natural gas containing H2S but also inspires further investigation for the cost-effective performance enhancement of Hg0 sorbents.

Synthesis and multi-objective optimization of fly ash-slag geopolymer sorbents for heavy metal removal using a hybrid Taguchi-TOPSIS approach

This study develops and evaluates a highly effective geopolymer sorbent specifically designed for the removal of heavy metals from wastewater. Single and binary blends of fly ash and slag were utilized as the binding material. The geopolymer composite was activated using either sodium hy solely or in combination with sodium silicate. The Taguchi method was employed to design the geopolymer mixes, having four factors, each with four levels of variation. These factors included the fly ash-to-slag ratio (FA), binder content (BC), the molarity of the sodium hydroxide solution (M), and the sodium silicate-to-sodium hydroxide ratio (SS/SH). The performance of the geopolymer sorbent was rigorously assessed against a comprehensive set of criteria, including metal sorption capacity, setting time, flowability, density, compressive strength, abrasion resistance, water absorption, permeable voids, sorptivity, carbon footprint, and cost. The TOPSIS methodology was applied to aggregate the response criteria and determine the optimal mix for superior performance. The results showed that the optimum mix consisted of an FA of 33 %, BC of 1050 kg/m3, M of 10, and SS/SH of 3. A sensitivity analysis confirmed that changes in the weighting of the performance criteria did not significantly impact the proportioning of the optimum mix. Furthermore, the analysis of variance (ANOVA) revealed that the FA contributed the most to the sorbent’s performance, followed by the SS/SH, BC, and M. The development of this geopolymer sorbent not only addresses a critical environmental concern but also offers great potential for practical applications in industries and municipalities worldwide.

Synthesis of Composite Sorbents with Chitosan and Varied Silica Phases for the Adsorption of Anionic Dyes.

In this work, various types of silica materials were used for the synthesis of chitosan-silica composites. The composites were obtained using the chitosan (Ch) immobilization process from an aqueous solution on various silica phases, i.e., amorphous diatomite (ChAD), crystalline diatomite (ChCD), mesoporous silica MCM-41 (ChMCM), and mesoporous silica SBA-15 (ChSBA). Textural, structural, morphological, and surface properties of the materials were determined by using various measurement techniques, i.e., low-temperature adsorption/desorption isotherms of nitrogen, X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), potentiometric titration, high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The adsorption properties towards various anionic dyes, i.e., acid red 88 (AR88), acid orange 8 (AO8), and orange G (OG), were evaluated based on kinetic and equilibrium measurements. The ChSBA, ChAD, and ChMCM composites were characterized by relatively high adsorption capacities (am) for AR88, with values equal to 0.78, 0.71, and 0.69 mmol/g, respectively. These composites were also distinguished by the rapid AR88 adsorption rate, with the values of half-time parameter t0.5 equal to 0.35, 2.84, and 1.53 min, respectively. The adsorption equilibrium and kinetic data were analyzed by applying the generalized Langmuir isotherm and the multi-exponential equation (m-exp), respectively. An interaction mechanism between the dyes and the obtained materials was proposed.

Development of a bifunctional material incorporating carbon microspheres for the intensified hydrogen production by sorption-enhanced glycerol steam reforming

Glycerol steam reforming is a green and sustainable alternative to hydrocarbon steam reforming for hydrogen production. Reaction intensification by in-situ CO2 removal using Ni/CaO-based bifunctional sorbent-catalyst materials was investigated in this paper to improve the hydrogen yield and purity significantly. Employing carbon microspheres as the foundation for sorbent synthesis resulted in the development of a hollow CaO sphere sorbent with higher and more stable sorption capacity over multiple adsorption/regeneration cycles compared to sorbents synthesized with conventional methods. The incorporation of different stabilizers improved further the capacity and stability of sorbents. The sorbent materials were tested under different sorption and regeneration temperatures in a dry and wet atmosphere. The intensified sorption-enhanced steam reforming process was evaluated under various reaction temperatures, weight hourly space velocities, and steam-to-carbon molar feed ratios. The bifunctional materials synthesized with carbon microspheres led to improved reaction performances, including a more extended pre-breakthrough period and a more stable behavior during reaction/regeneration cycles.

Validation of an efficient analytical method for quantification of tetracycline antibiotic residues in egg samples along with investigating their decontamination using ultraviolet waves

ABSTRACT This study describes the development and application of a dispersive solid-phase extraction procedure combined with dispersive liquid – liquid microextraction for the extraction of tetracycline antibiotics from egg samples. In this method, a bio-metal organic framework was prepared and used in extraction of the analytes from sample solution. In this method, the sorbent synthesis was relatively easy and its crosslinker was vitamin B3 which is a green chemical compound. The sorbent provides particles can extract the analytes via interactions such as surface adsorption, occlusion van der waals and π–π interactions. The extraction procedure was done by mixing trichloroacetic acid with the egg sample to remove the sample proteins and then the synthesised sorbent at mg – level was added to the supernatant phase and the mixture was vortexed. After centrifuging, the supernatant phase was removed and sorbent particles containing the extracted analytes were eluted using acetonitrile. After that, this phase containing the analytes was taken and used in the following dispersive liquid – liquid microextraction process that was done to more enrichment the analytes using a deep eutectic solvent. After optimisation of the extraction process, sensitive limits of detection and quantification were found in the ranges of 0.21–0.28 and 0.70–0.93 ng g−1, respectively. Acceptable extraction recoveries of the analytes ranged from 60 to 73%. The method was selective regarding the analytes, as there were no interfering peaks eluted at the retention times of the analytes. After the validation step, the offered method was employed for the determination of the tetracycline antibiotics in various egg samples and the effect of ultraviolet waves in decontaminating them from egg samples was investigated.

Автоматизация расчета реактора для синтеза серосодержащего сорбента, предназначенного для извлечения из сточных вод ионов тяжелых металлов

An automated algorithm for calculating the time of the full cycle of operation, the stages of thermal stabilization and cooling of the reaction mixture in a reactor designed for the synthesis of a sulfur-containing sorbent produced on the basis of waste products from metallurgy, petrochemistry (sulfur), epichlorohydrin (1, 2, 4-trichloropropane) and the pulp and paper industry (lignin) for extraction from wastewater of heavy metal ions. The use of algorithms and a program for automated calculation of the reactor helps to reduce the complexity of production costs and the cost of the finished sorbent, increases the reliability of calculations and the quality of design solutions. The developed algorithms and program include the following calculation routines: physico-chemical properties of the components of the reaction mixture and the choice of a mixing device (propeller three-bladed agitator), taking into account the viscosity of the mixture; hydrodynamic calculation of the mixing device and heat transfer when heating the mixture from 20 to 45 °C; heat transfer during thermal stabilization and cooling of the working mixture, as well as the time of the full cycle of the reactor. The proposed algorithm of heat transfer during thermal stabilization of the reaction mass is based on the determination of the temperature range of water heating, compensating for heat losses. For this purpose, the inverse problem of heat transfer with unknown temperatures over a hot heat carrier is formulated and solved, such that the average value between them is a thermostabilizable value. An algorithm for calculating the cooling process of the reaction mixture in a sulfur-containing sorbent synthesis reactor, taking into account heat losses to the environment in the amount of 5%, is presented. A program has been developed that implements the presented algorithms in C#, designed to automate the calculation of a sulfur-containing sorbent synthesis reactor designed to extract heavy metal ions from wastewater.

New Sorbents Based on Polyacrylonitrile Fiber and Transition Metal Ferrocyanides for 137Cs Recovery from Various Composition Solutions

For the first time, new sorbents based on polyacrylonitrile (PAN) fiber and transition metal ferrocyanides were obtained. The main difference between the obtained sorbents and the existing ones is the stage of preliminary preparation of the initial support by converting it into the forms PAN-Fe(OH)3 or PAN-MnO2, due to which additional ion exchange groups (carboxyl, carbonyl, etc.) are formed, which increases the amount of ferrocyanide fixed to the support. The best components and conditions for the synthesis of new sorbents were determined (concentration (0.1–0.2 mol/L), as well as pH (1 for sorbents based on PAN-Fe(OH)3, and 1–5—PAN-MnO2) of potassium ferrocyanide solution, concentration of transition metal salts (0.02 mol/L), temperature conditions). The influence of the studied solution composition (pH, concentration of Na+, K+, NH4+ ions) on the cesium distribution coefficients during its recovery by the obtained sorbents was assessed. The possibility of cesium recovery from solutions with pH 1–9 containing macro quantities of cations was demonstrated. The sorbents derived were characterized by modern structural methods such as infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy with EDS analysis. A study of the trace amount sorption of 137Cs was carried out in comparison with commercially available highly efficient sorbents (FNS-10 and Termoksid-35), and it was shown that the resulting sorbents are not inferior to industrial ferrocyanide sorbents and can be used for 137Cs selective sorption from technological solutions and natural waters.

Synthesis of Manganese Oxide Sorbent for the Extraction of Lithium from Hydromineral Raw Materials.

The article presents the research results for the synthesis of inorganic sorbents based on manganese oxide compounds. It shows the results of the lithium sorption from brines with the use of synthesized sorbents. The effect of temperature, the molar ratio of Li/Mn, and the duration for obtaining a lithium-manganese precursor and its acid treatment was studied. The sorption characteristics of the synthesized sorbents were studied. The effect of the ratio of the sorbent mass to the brine volume and the duration of the process on the sorption of lithium from brine were studied. In this case, the sorbent recovery of lithium was ~86%. A kinetic model of the lithium sorption from brine on a synthesized sorbent was determined. The kinetics of the lithium sorption was described by a pseudo-second-order model, which implies limiting the speed of the process due to a chemical reaction.

In situ activation synthesis of tire-derived sorbents for efficient immobilization of elemental mercury from flue gas

Mercury removal from coal combustion flue gas remains a daunting challenge because of the lack of cost-effective sorbents. In this study, the in situ activation synthesis of tire chars was realized through SO2 induction and the tire-derived sorbents were used for elemental mercury (Hg0) removal from the simulated flue gas. Therein the sulfur species in tire chars are regulated. The results indicated that the specific surface area of tire chars was slightly decreased whereas more micropores were generated after SO2 activation. Compared with raw tire char, the sulfur content of tire-derived sorbents was obviously increased. The tire-derived sorbents also contained more sulfur- and oxygen-containing functional groups. For this reason, the Hg0 removal performance of tire-derived sorbents was dramatically increased after SO2 activation. The optimum pyrolysis temperature for the synthesis of tire-derived sorbents was 600 °C. The SO2 concentration in activation atmosphere had little effect on the Hg0 removal performance of tire-derived sorbents. The presence of SO2, NO and O2 was beneficial for Hg0 removal·H2O had little effect on Hg0 removal. The Hg0 adsorption capacity of tire-derived sorbents was further compared with the previously reported sorbents through adsorption dynamic simulations. Furthermore, the mechanism of Hg0 removal over tire-derived sorbents was revealed through XPS analysis and mercury temperature programmed desorption. It was found that the Hg0 removal process was mainly dominated by chemisorption, where organic sulfur species, CO group and COOH/C(O)–O–C group served as active sites for Hg0 capture.

Induced synthesis of SO2-promoting and H2O-tolerant sorbents for elemental mercury removal from flue gas

In this study, novel S-doped sorbents synthesized via one-step co-pyrolysis of biomass and scrap tires under SO2 atmosphere were developed for elemental mercury (Hg0) removal from coal-fired flue gas. The presence of SO2 could regulate the sulfur species in S-doped sorbents and improve their Hg0 removal performance. Sample characterization exhibited that SO2 activation increased the sulfur content and decreased the carbon content in sorbents due to the occurrence of carbothermal reduction reaction. The specific surface area, pore volume, and micropore content in S-doped sorbents were obviously improved compared with raw sorbents. After SO2 activation, partial inorganic sulfide was converted into sulfur-containing functional groups and more oxygen-containing functional groups were generated on the sorbents. The S-doped sorbents presented more excellent performance for Hg0 removal compared with raw sorbents. The optimal pyrolysis temperature and SO2 concentration in activation atmosphere were 700 °C and 10%, respectively. It was surprising that SO2 facilitated Hg0 removal and the S-doped sorbents showed good water-resistance due to the presence of ZnS. O2 and NO had positive effects on Hg0 removal. A close fitting to the pseudo-second-order model was obtained for the behavior of Hg0 removal over S-doped sorbents. Aliphatic sulfur, sulfoxide, carbonyl and carboxyl/ester groups functioned as active components for Hg0 removal.

An Overview of Developments In Silica Gel Matrix Composite Sorbents for Adsorption Chillers with Desalination Function

Adsorption cooling technology is a promising alternative to replace conventional solutions. However, adsorption chillers still need to be improved in terms of performance parameters. One of the most important factors affecting their efficiency is the characteristics of the adsorbent, which should have the highest adsorption capacity and enable efficient heat transport in the bed. The objective of this paper is to present current developments in the field of composite sorbents with silica gel matrix as modern and very promising materials and then perform a detailed analysis of them. The paper summarises the methods of synthesis of composite sorbents and the current knowledge concerning these materials. The analysis focuses on a comparison of the available data, particular taking into account the types of matrixes, so that the analysis provides a clear and qualitative basis for further research. As a result of exploring the state of the art, this subject is found to be insufficiently described; therefore, these materials are comprehensively analysed in terms of their properties and the impact of their use on the COP (coefficient of performance) and SCP (specific cooling power) of adsorption chillers. Based on the analysis of the literature, the most promising directions for further research are also indicated.

Origins and Formation of Ion Chromatography

The origins and ways of formation of ion chromatography are shown. Little-known facts and publications are reflected, and a significant influence of the development of instrument making in HPLC and technologies for the synthesis of low-capacity sorbents on the development of this method is demonstrated. The early history of developments in the field of ion chromatography in the US scientific groups of H. Small (Dow Chemical and Dionex Corp.) and J. Fritz (Iowa State University) is described, and the scientific works and key achievements of these scientists are analyzed.

Low-cost process for synthesis of sorbents from ilmenite ores in Abu Ghalaga, Egypt and their uses in biological activity

Low-cost process for synthesis of sorbents from ilmenite ores in Abu Ghalaga, Egypt and their uses in biological activity

Inverse Vulcanized Polymers for Sustainable Metal Remediation

AbstractHeavy metal exposure has an enormous burden on human health. Current metal removal technologies require substantial improvements in relation to their efficiency and environmental impact if this issue is to be addressed. Over the last decade, several new types of sulfur‐rich sorbents have been investigated. These polymers typically have high removal efficiencies for toxic metals such as mercury and are often made using sustainable and low‐cost reagents. This review surveys polymers made by inverse vulcanization that have been tested for metal capture. Focus is put on environmental impact, feedstock for sorbent synthesis, selectivity towards metal removal, toxicity studies, and the reusability of the polymers. Furthermore, this review discusses current limitations and the potential opportunities to use different comonomers for improved metal capture.

Carbonate treated coffee powder (CTCP) for selective sorption of Pu4+ over Am3+, Np4+, NpO22+, and PuO22+ from aqueous acidic solution: Investigation on mechanism, kinetics, thermodynamics, stripping and radiolytic stability

An attempt was made for understanding the sorption behaviour of different actinide ions Pu4+, PuO22+, Am3+, Np4+, and NpO22+ on carbonate treated exhausted coffee powder (CTCP). Very efficient sorption of Pu4+ over other actinide ions from aqueous acidic medium was observed. Almost 4 h were required for achieving equilibrium. Experimental results for Pu+4 were fitted into different sorption isotherm model: Langmuir isotherm, Freundlich isotherm, D.R, isotherm and Temkin isotherm. Based on the linear regression, it was found that, Freundlich isotherm was predominantly operative. Pseudo 2nd order kinetics was found to be effective for the sorption of Pu+4. More than 80 % of loaded Pu4+ was found to desorb by 0.25 M oxalic acid solution. CTCP exhibited relatively good radiation stability. Sorption of Pu+4 on CTCP was exothermic, and spontaneous in nature. The sorption process was simple, cost effective and environmentally benign, as it did not involve any sophisticated, multi-step, sorbent synthesis.

Cigarette butt-assisted combustion synthesis of dolomite-derived sorbents with enhanced cyclic CO2 capturing capability for direct solar-driven calcium looping

Calcium looping (CaL) is a promising technology for CO2 capture owing to the widespread applicability and low-cost CaO-based sorbents. However, the SO2 and ash from coal combustion in O2/CO2 atmosphere for CaO regeneration is prone to cause rapid degradation for CaO-based sorbent. Hereby, a direct solar-driven CaL system is proposed to eliminate the adverse influence of coal combustion on CaO-based sorbent. Different unitary Mn-doped and binary-doped (Mn/Fe-, Mn/Cu- and Mn/Co-doped) dolomite-derived sorbents were synthesized by cigarette butt-assisted combustion method. The higher Mn doping ratio, the higher solar absorptance for unitary Mn-doped sorbent due to the gradually deepened blackness of the sample. Comprehensively considering the solar absorptance and CO2 capture performance, the unitary Mn-doped sorbent (Ca&Mg: Mn=100:10) is an optimal candidate, which has a solar absorptance of 63.6 % and a carbonation conversion of 64.3 % in the 20th cycle. Compared with the unitary Mn-doped sorbent (Ca&Mg: Mn=100:10), the binary-doped sorbent (Ca&Mg: Mn: Fe=100:5:5) exhibits a comparable CO2 capture capacity and a higher solar absorptance of 76.7 %. More importantly, the binary-doped sorbent (Ca&Mg: Mn: Fe=100:5:5) possesses the markedly faster CO2 capture rate in the early carbonation stage due to the increased lattice defect of CaO.

Synthesis of Polymeric Sorbents with Magnetic Properties

In this work, a procedure for the synthesis of polymeric sorbents based on hypercrosslinked polystyrene (HPS) with magnetic properties was developed. The technique is based on the reduction of iron salts with polyhydric alcohols at high temperature in an inert atmosphere. The resulting sorbents retain their original characteristics: an extended specific surface area, micro-mesoporous structure, acquiring magnetic properties, which makes it possible to use them as magnetically separable sorbents, supports for the active phase of heterogeneous catalytic systems etc.

Facile, time-saving cigarette butt-assisted combustion synthesis of modified CaO-based sorbents for high-temperature CO2 capture

Highly efficient and stable Zr-incorporated CaO-based sorbents were synthesized using a facile, cigarette butt-assisted combustion synthesis (CAC) method. Comparative investigation of CAC method with two common synthesis methods (i.e., wet-mixing, sol–gel) on producing CaO-based sorbents was conducted. The sorbents synthesized by the CAC and sol–gel methods exhibit superior cyclic CO2 capture capability compared to wet-mixing. More importantly, the CAC belongs to impregnated layer solution combustion synthesis and takes markedly shorter time compared to sol–gel, possessing the potential of scaled-up preparation. The optimization of combustion temperature and incorporation ratio of Zr-based support on synthesis of CaO-based sorbents by CAC method was further conducted. The proper combustion temperature selected to synthesize Zr-incorporated CaO-based sorbents using CAC method is 750 °C. Too high or low combustion temperature may result in unsatisfactory pore structure of synthetic CaO-based sorbents because of excessive sintering or generating in-situ CaCO3, respectively. The synthetic CaO-based sorbents with 25 wt% of ZrO2 exhibit the outstanding CO2 capture performance (CaO carbonation conversion of 63.8% after 17 cycles) due to the generation of extensive CaZrO3 grains acting as the inert skeleton. Additionally, the combination of cigarette butt-assisted combustion and graphite-moulding can prepare Zr-incorporated CaO-based pellets with desirable practicality.