CO[2] Sequestration by Natural Zeolite for Greenhouse Effect Control

This paper describes the adsorption of CO[2] on pores in natural erionite exchanged with aqueous solutions of Na{+}, Mg{2+}, and Ca{2+} salts at different concentrations, variable time and temperature of treatment. Experimental data of CO[2] adsorption were treated by the Freundlich and Langmuir equations. Complementarily were evaluated standard adsorption energies and the degree of interaction of the gas with the zeolite; the evolution of isosteric heats of adsorption was analyzed. The exchange with Na{+} favors the creation of emergent pores thus causing an increase of the adsorption capacity for CO[2]. The presence of Na{+} at micropore entrances causes an increased adsorption into the nanocavities and on the external area of the ion-exchanged zeolites. The development of nanopores in erionite was evaluated through the Barrett-Joyner-Halenda and NLDFT methods. Depending on the conditions of the exchange treatment, Na{+} was found to be most favorable, well distributed, and accessible for N[2] adsorption

Synthesis of Novel Regenerable 13X Zeolite-Polyimide Adsorbent Foams

A new generic synthesis method is presented for the production of a polyimide (PI)/adsorbent (80 wt% 13X zeolite) regenerable foam filter. The method uses a dual parallel reaction foaming process comprising CO 2 generation (blowing) and polymerisation reactions. The paper describes the development of the foam structure and its characterisation in the context of removing CO 2 from air. Polyvinylpyrrolidone (PVP) of different molecular weights (10k, 40k and 58k) was used as a pore former to allow more adsorption sites to be exposed to CO 2. In dynamic adsorption breakthrough experiments at 101.325 kPa and 293 K, 10k PVP foams demonstrated an equilibrium loading of 0.039 g g −1 for CO 2 (at 40,000 ppmv in air), showing the best equilibrium time and adsorption capacity. The foams and equivalent commercial 13X beads were able to achieve loadings of 0.094 g g −1 and 0.097 g g −1 (at 40 mbar), respectively, when tested using pure CO 2 in an Intelligent Gravimetric Analyser. At pressures beyond 100 mbar, a weighted average isotherm shows only a 1.3 wt% reduction in adsorption capacity due to the polymer binder. The foams showed superior CO 2/N 2 selectivity compared to other adsorbents in literature. The thermal analysis of pure PI and 13X powder showed that the foams can be regenerated at 300 °C. Computational Fluid Dynamics simulation was successfully implemented in order to understand the CO 2 adsorption behaviour on the new foam filter. Such modelling proved to be invaluable in understanding adsorptive behaviour through the complex foam structures as this is difficult to achieve experimentally. </p

Adsorption of carbon dioxide with nanofibers based on alginate/polyethylene oxide/triton X-100

Nanofiber is a material composed of nanometer-scale fibers with carbon or polymer base materials.The easiest and most economical method of nanofiber synthesis is electrospinning. The most economical method of nanofibers synthesis is electrospinning.Nanofiber has the high potential for CO 2 adsorption because it has high gas transport resistance and high kinetic (Wang and Li, 2014). Nanofiber has a high potential for CO2 adsorption because it has high gas transport resistance and high kinetic [1].Application of synthetic polymer-based nanofiber for CO 2 adsorption has been carried out by several researchers including PVDF nanofiber (Hong et al., 2014), phenolic resin nanofiber (Nan et al., 2015), and PDMS/PVDF nanofiber (Lin et al., 2016). Research on the synthesis of Alginate/Polyethylene oxide/Triton X-100 nanofibers (Alg/PEO/TX NFS) by electrospinning method for CO 2 adsorption was carried out.Research on synthesis of Alginate/Polyethylene oxide/Triton X-100 nanofibers (Alg/PEO/TX NFs) by electrospinning for CO2 adsorption was carried out.This study aims to determine the composition of Alg/PEO that can produce fibers without beads; The purpose of this research werethe effect of adding PEO and TX to the electrospinnability of the solution ; to study the effect of adding PEO and TX to the electrospinnability of the solution, andthe effect of flow rate and contact time on adsorption capacity; the effect of the gas flow rate and contact time on adsorption capacity and the study of CO 2 adsorption isotherm by Alg/PEO/TX NFS.of  Alg/PEO/TX NFs.Polymer solutions were characterized by conductivity meters and tensiometers, while nanofibers were analyzed using optical microscopy, SEM, and FTIR. Polymer solutions were characterized by the conductivity meter and tensiometer, while the nanofibers were analyzed using optical microscopy, SEM, and FTIR.The study of CO 2 adsorption in nanofiber includes the effect of flow rate and CO 2 contact time on nanofiber, then studied adsorption isotherm. The study of CO2 contact time includes the effect of flow rate and CO2 contact time on nanofiber. The results showed that Alg/PEO/TX NFS without beads were successfully synthesized from a solution of Alg/PEO with a volume ratio of 1:2 and an addition of 0.5% (v/v) TX.The results showed that Alg/PEO/TX NFs were successfully synthesized with a volume ratio 1/2 of Alg/PEO blends solutions and a small addition of 0.5% (v/v) TX.The bead s without nanofiber produced were 201,567 ± 48 nm in diameter and have a surface area of 34,963 m 2 g -1 . The beads-free nanofibers produced was 201 ± 48 nm in diameter and with a surface area of 34,963 m2.g-1.The optimum adsorption capacity was obtained at the rate of 10 mL minute -1 with a contact time of 25 minutes was 12,398 mmol g -1 . The optimum adsorption capacity was 12,398 mmol.g-1, which wasobtained at the flow rate of 10 mL.minute-1 and a contact time of 25 minutes

Adsorption of Carbon Monoxide (CO) in ZSM-5 Membrane on Smoking Area

This research aims to know the ability of ZSM-5 adsorbed on the cigarette smoke so that it can reduce the levelsof CO in the smoking area. Zeolite membranes formed from steel AlSi316 gauze covered with ZSM-5 prekusor with size of 5 cm, 4 cm, 3 cm, 2 cm and 1 cm are kept at a temperature of 900C for 4 days then characterizedusing x-ray diffraction (XRD), FTR and SEM, with absorbance test place the gauze into the enclosed spacevolume 18.000 cm3 containing CO from cigarette smoke.The research was recently reached the stage ofinorganic and organic substances leaching and oxidized in electrochemistry in H2SO4 to 20% We use the result of the previous research by title Adsorption test of Carbon monoxide using Lampung and Malang natural zeolite, by Aditya Zulfa. In that research, Malang and Lampung natural zeolite are being tested its adsorption capacity of CO in pressure condition 0 to 178 psia with 25 psi interval and using variation of adsorbent size and adsorbtion temperature. Both of those zeolites are being compared its adsorbtion capacity, before and after the activation process.The result of Lampung natural zeolite which has the highest adsorption capacity CO, 0,5866 mmol/g at 175 psia. So, it can be found the best specification of an adsorbent which has the highest adsorption capacity of CO between two of natural zeolite.  Keywords: Adsorption, Carbon Monoxide (CO), ZSM-5 Membrane, Smoking Are

Optimized cesium and potassium ion-exchanged zeolites A and X granules for biogas upgrading

Partially ion-exchanged zeolites A and X binderless granules were evaluated for CO(2) separation from CH(4). The CO(2) adsorption capacity and CO(2)-over-CH(4) selectivity of binderless zeolites A and X granules were optimized by partial exchange of cations with K(+) and Cs(+), while retaining the mechanical strength of 1.3 MPa and 2 MPa, respectively. Single gas CO(2) and CH(4) adsorption isotherms were recorded on zeolites A and X granules and used to estimate the co-adsorption of CO(2)–CH(4) using ideal adsorbed solution theory (IAST). The IAST co-adsorption analysis showed that the partially ion-exchanged binderless zeolites A and X granules had a high CO(2)-over-CH(4) selectivity of 1775 and 525 respectively, at 100 kPa and 298 K. Optimally ion-exchanged zeolite X granules retained 97% of CO(2) uptake capacity, 3.8 mmol g(−1), after 5 breakthrough adsorption–desorption cycles while for zeolite A ion-exchanged granules the reduction in CO(2) uptake capacity was found to be 18%; CO(2) uptake capacity of 3.4 mmol g(−1). The mass transfer analysis of breakthrough experimental data showed that the ion-exchanged zeolite X had offered a higher mass transfer coefficient, (κ) through the adsorption column compared to zeolite A; 0.41 and 0.13 m s(−1) for NaK(4.5)Cs(0.3)X and CaK(2.5)Cs(0.2)A, respectively

Adsorption of hydrogen sulphide over rhodium/silica and rhodium/alumina at 293 and 873 K, with co-adsorption of carbon monoxide and hydrogen

In this study, we have examined the adsorption of hydrogen sulphide and carbon monoxide over rhodium/silica and rhodium/alumina catalysts. Adsorption of hydrogen sulphide was measured at 293 and 873 K and at 873 K in a 1:1 ratio with hydrogen. At 293 K, over Rh/silica, hydrogen sulphide adsorption capacity was similar to that of carbon monoxide; however, over Rh/alumina, the carbon monoxide adsorption capacity was higher, probably due to the formation of RhI(CO)2. Over Rh/silica, the primary adsorbed state was HS(ads), in contrast to Rh/alumina, where the H2:S ratio was 1:1 indicating that the adsorbed state was S(ads). Competitive adsorption between CO and H2S over Rh/silica and Rh/alumina revealed adsorption sites on the metal that only adsorbed carbon monoxide, only adsorbed hydrogen sulphide or could adsorb both species. At 873 K, hydrogen sulphide adsorption produced the bulk sulphide Rh2S3; however, when a 1:1 H2:H2S mixture was used formation of the bulk sulphide was inhibited and a reduced amount of hydrogen sulphide was adsorbed

Nanoclay-Based Solid-Amine Adsorbents for Carbon Dioxide Capture

The objective of this research was to develop an efficient, low cost, recyclable solid sorbent for carbon dioxide adsorption from large point sources, such as coal-fired power plants. The current commercial way to adsorb CO 2 is to use a liquid amine or ammonia process. These processes are used in industry in the sweetening of natural gas, but liquid based technologies are not economically viable in the adsorption of CO2 from power plants due to the extremely large volume of CO2 and the inherent high regeneration costs of cycling the sorbent. Therefore, one of the main objectives of this research was to develop a novel sorbent that can be cycled and uses very little energy for regeneration.;The sorbent developed here is composed of a nanoclay (montmorillonite), commonly used in the production of polymer nanocomposites, grafted with commercially available amines. (3-aminopropyl) trimethoxysilane (APTMS) was chemically grafted to the edge hydroxyl groups of the clay. While another amine, polyethylenimine (PEI), was attached to the surface of the clay by electrostatic interactions. To confirm the attachment of amines to the clay, the samples were characterized using FTIR and the corresponding peaks for amines were observed. The amount of amine loaded onto the support was determined by TGA techniques. The treated clay was initially analyzed for CO2 adsorption in a pure CO 2 stream. The adsorption temperatures that had the highest adsorption capacity were determined to be between 75°C and 100°C for all of the samples tested at atmospheric pressure. The maximum CO2 adsorption capacity observed was with nanoclay treated with both APTMS and PEI at 85°C. In a more realistic flue gas of 10% CO2 and 90% N2, the adsorbents had essentially the same overall CO2 adsorption capacity indicating that the presence of nitrogen did not hinder the adsorption of CO2. Adsorption studies in pure CO2 at room temperature under pressure from 40-300 PSI were also conducted. The average adsorption capacity for the adsorbents did not change significantly over the range of pressures studied, indicating that the uptake of CO2 was due mainly to chemical reaction and not to the physical absorption of CO2. The average CO2 adsorption capacity at 300 psi and room temperature for clay treated with APTMS alone was 7.6 wt% CO2. The combination of APTMS and PEI treatment increased the average adsorption capacity to 11.4 wt% CO2.;The regeneration method for the majority of the adsorption tests employed pure N2 at 100°C as a sweep gas, and it was successful in regenerating the adsorbent. The regeneration of the adsorbent was also studied with pure and humid CO2 at 155°C. Using CO2 as a sweep gas for regeneration is more commercially relevant and was able to regenerate the sorbents. Vacuum regeneration and the stability of the adsorbents to water vapor were also studied. Our studies showed that the developed adsorbents were able to adsorb CO2 at atmospheric conditions using pure CO 2 as well as 10% CO2 and 90% nitrogen. Additionally, the adsorbents developed have the potential to be cycled using commercially applicable regeneration schemes. While these results are comparable to results of other emerging CO2 adsorption technologies, our adsorbent has the benefit of a very cheap support, and it could provide a commercially useful CO 2 adsorbent

Nickel and cobalt adsorption on hydroxyapatite: a study for the de-metalation of electronic industrial wastewaters

In the present study, the Ni(II) and Co(II) adsorption efficiency and selectivity, as well adsorption mechanisms on a stoichiometric hydroxyapatite (HAP) surface have been investigated. Characterization studies (N-2 adsorption/desorption and X-ray powder diffraction (XRPD) analyses) and adsorption tests under various operative conditions provided detailed information about the use of HAP in the de-metalation of wastewaters containing Ni and Co as polluted metal species. The sorption capacity of HAP has been evaluated by static batch adsorption tests varying initial concentration of Ni(II) and Co(II) species (from ca. 0.25 to 4.3mM), contact time (from 15min to 24h), and pH (from 4 to 9) operative parameters. Proposed mechanisms of adsorption of Ni(II) and Co(II) on HAP surface are ion-exchange and surface complexation; a partial contribution of chemical precipitation from bulk solution should be considered at pH 9. In addition, adsorption isotherms of Ni(II) and Co(II) on HAP have been collected at 30 degrees C and pH 4 and modeled by employing different equations. The maximum sorption capacities have been quantified as 0.317mmolgHAP-1 (18.6mggHAP-1) and 0.382mmolgHAP-1 (22.5mggHAP-1) for Ni(II) and Co(II), respectively. Selectivity to Co and Ni in the adsorption process on HAP has also been investigated; HAP has higher affinity towards Co than Ni species (Co:Ni=2.5:1, molar ratio)

Removal of Lead and Arsenic from Aqueous Solution by Biochar Produced from Locally-Sourced Biomass

This study evaluated the effectiveness of four adsorbent materials, pyrolyzed corn stover, orange peel, pistachio shell, and magnetic biochar for their ability to adsorb lead (Pb) and arsenic (As III, As V) from aqueous solution. An increase in adsorption was seen as the pH of the solution increased from pH 2 to pH 6. Magnetic orange peel biochar with Fe3O4 particles precipitated on the surface of biochar was synthetized by co-precipitation and used for arsenic adsorption. Initial pH value had an influence on the adsorption behavior of As (III) and As (V). In the pH range of 2–6, As (V) adsorption was observed to decrease with increasing pH, with highest adsorption occurring at pH 2; As (III) adsorption had the highest capacity around pH 4–6

Carbon-Dot-Sensitized, Nitrogen-Doped TiO2in Mesoporous Silica for Water Decontamination through Nonhydrophobic Enrichment-Degradation Mode

Mesoporous silica synthesized from the co-condensation of tetraethoxysilane and silylated carbon dot containing amide group has been adopted as the carrier for the in-situ growth of TiO2 through an impregnation-hydrothermal crystallization process. Benefitted from the initial complexing between the titania precursor and carbon dot, highly dispersed anatase TiO2 nanoparticles can be formed inside the mesoporous channel. The hybrid material possesses ordered hexagonal mesostructure with a p6mm symmetry, high specific surface area (446.27 m2g-1), large pore volume (0.57 cm3g-1), uniform pore size (5.11 nm) and a wide absorption band between 300-550 nm. TiO2 nanocrystals are anchored to carbon dot through bonds of Ti-O-N and Ti-O-C as revealed by X-ray photoelectron spectroscopy. Moreover, the nitrogen doping of TiO2 is also verified by the formation of Ti-N bond. This composite shows excellent adsorption capability to organic 2, 4-dichlorophenol and acid orange 7 with electron-deficient aromatic ring through the electron donor-acceptor interaction between carbon dot and organics instead of hydrophobic effect as analyzed by the contact angle analysis, which can be photocatalytically recycled through visible light irradiation after the adsorption. The narrowed bandgap by nitrogen doping and the photosensitization effect of carbon dot are revealed to be co-responsible for the visible-light activity of TiO2. The adsorption capacity does not suffer obvious loss after being recycled 3 times