Carbon Dioxide Adsorption Capacity Research Articles

A simulation study of reducing carbon dioxide and hydrogen sulfide adsorption in dehydration beds

In natural gas dehydration units, a problem that may arise is the increased concentration of carbon dioxide and hydrogen sulfide in their feed. During the adsorption stage, these gases are adsorbed along with water by the dehydration bed. During the regeneration stage, these adsorbed gases are desorbed from the bed. Their presence along with water and high temperatures causes the equipment and pipes in the regeneration path to corrode. Therefore, minimizing the adsorption of these gases in dehydration beds is imperative. Based on simulations of Aspen Adsorption, three solutions have been described and investigated in this article. The first solution is using 3 A adsorbent which has a lower adsorption capacity for carbon dioxide and hydrogen sulfide than other adsorbents like 4 A. But this adsorbent also has a lower adsorption capacity for water, so the first solution needs more cycles for the gas dehydration process. This reduces the adsorbent lifetime. Increasing the duration of the adsorption stage is the second solution. This solution has little effect and cannot solve the problem. The third solution is layering the dehydration bed with different adsorbents. This solution can reduce carbon dioxide and hydrogen sulfide adsorption by 48.7% and 49.9%, respectively, when 3 m of 3 A adsorbents are used at the bottom and 3.5 m of 4 A adsorbents are used at the top of the bed.

Impregnation of biochar with montmorillonite and its activation for the removal of azithromycin from aqueous media.

An inexpensive and environmentally friendly composite synthesized from rice husk, impregnated with montmorillonite and activated by carbon dioxide, was investigated for the removal of azithromycin from an aqueous solution. Various techniques were used to characterize adsorbents in detail. The sorption process was primarily regulated by the solution pH, pollutant concentration, contact duration, adsorbent dose, and solution temperature. The equilibrium data were best analyzed using the nonlinear Langmuir and Sips (R2 > 0.97) isotherms, which revealed that adsorption occurs in a homogenous manner. The adsorption capacity of pristine biochar and carbon dioxide activated biochar-montmorillonite composite was 33.4mgg-1 and 44.73mgg-1, respectively. Kinetic studies identified that the experimental data obeyed the pseudo-second-order and Elovich models (R2 > 0.98) indicating the chemisorption nature of adsorbents. The thermodynamic parameters determined the endothermic and spontaneous nature of the reaction. The ion exchange, π-π electron-donor-acceptor (EDA) interactions, hydrogen-bonding, and electrostatic interactions were the plausible mechanisms responsible for the adsorption process. This study revealed that a carbon dioxide activated biochar-montmorillonite composite may be used as an effective, sustainable, and economical adsorbent for the removal of azithromycin from polluted water.

Boosting carbon dioxide adsorption capacity applying Jellyfish optimization and ANFIS-based modelling

Carbon capture and storage (CCS) are essential for controlling global warming. Among the different CCS technologies, adsorption using amines is promising and applied on an industrial scale. In this research work, the optimal values of tetraethylenepentamine (TEPA), imidazole (Im) and temperature are identified to boost CO2 adsorption capacity. The proposed methodology integrates Jellyfish optimization (JO) and ANFIS-based modelling. In the first step, using measured data, ANFIS model is constructed to simulate the CO2 adsorption capacity in terms of the mentioned parameters. The second step, using JO, the best values of temperature, TEPA, and Im are identified to maximize the CO2 adsorption capacity. To confirm the superiority of the integration between JO and ANFIS, the main findings were compared with response surface methodology and measured data. The proposed strategy succeeded in boosting the CO2 capture adsorption from 4.27 (mmol/g) to 5.25 (mmol/g).

Boron Nitride from Ammonia Borane and Alkali Amidoboranes and Its Features for Carbon Dioxide Capture

Herein, three boranes are studied as potential precursors of boron nitride (BN) and their carbon dioxide adsorption capacity is evaluated. The selected boranes are ammonia borane (AB, NH3BH3), lithium amidoborane (LiAB, LiNH2BH3), and sodium amidoborane (NaAB, NaNH2BH3), and they are pyrolyzed at four different temperatures. All the characterization techniques show the formation of BN from the three boranes. However, LiAB and NaAB form hexagonal BN (h‐BN) at a lower temperature in comparison with AB. The insertion of the alkali metal inside the BN structure is also evidenced. These materials show interesting results when they are exposed to a CO2 atmosphere. The materials are able to adsorb CO2 at nearly ambient conditions, and the best results are achieved with samples that do not present a crystalline structure. AB treated at 600 °C uptakes 34 cm3 g−1 (66.8 mg g−1) at 1.5 bar CO2 and 30 °C. Considering that the materials developed in this study are nonporous, the results are promising, opening new perspectives as potential sorbents for CO2.

Fluorescence properties of stable porous Zr(IV)-metal-organic framework based on fluorescent imidazolate-ligand

Three crystalline network compounds, ZrLimi-X based on four-connecting ligand with imidazole-derived chromophore were prepared by solvothermal methods. The three materials possess scu topology with large surface area and porosity. ZrLimi-X exhibit excellent thermal stability and chemical stability in both acidic and alkaline aqueous solutions. The three MOFs display good carbon dioxide adsorption capacity and interesting fluorescence properties. The peak position of fluorescence maximum emission and fluorescent lifetime of the ligand or MOFs with different stepwise methylation of imidazole show opposite trend of change caused by the methylation of imidazole which can reduce the conjugation of the ligands.

Preparation and characterization of activated carbon modified by potassium for carbon dioxide/methane adsorption and separation

AbstractIn this study, potassium nitrate, which was confirmed feasible to improve the adsorption capacity of carbon dioxide and separation of carbon dioxide/methane mixture, was utilized to modify the commercial coconut shell activated carbon. Three parameters, including potassium ion concentration, modification temperature and modification time, were investigated. The best sample is obtained when impregnating in potassium nitrate solution of 0.1 mol L−1 at 55 °C for 12 h according to its adsorbed amount capacity and separation effect. The saturated adsorbed amount of carbon dioxide on the optimal sample reaches up to 12.25 mmol g−1. In addition, the selectivity for a binary mixture with volume ratio of 60/40, 50/50 and 40/60, which is considered in the range of typical landfill gas, are 6.86, 6.62 and 6.39, increasing by 45.9 %, 43.6 % and 41.4 %, respectively. The adsorbent obtained in this study is promising in the adsorption and separation of carbon dioxide and methane industrially. Moreover, the method of modifying by potassium ion provides a potential way in improving the property of the adsorbents.

One-Pot Synthesis of Aminated Bimodal Mesoporous Silica Nanoparticles as Silver-Embedded Antibacterial Nanocarriers and CO2 Capture Sorbents.

Mesoporous silica nanoparticles have highly versatile structural properties that are suitable for a plethora of applications including catalysis, separation, and nanotherapeutics. We report a one-pot synthesis strategy that generates bimodal mesoporous silica nanoparticles via coassembly of a structure-directing Gemini surfactant (C16-3-16) with a tetraethoxysilane/(3-aminopropyl)triethoxysilane-derived sol additive. Synthesis temperature enables control of the nanoparticle shape, structure, and mesopore architecture. Variations of the aminosilane/alkylsilane molar ratio further enable programmable adjustments of hollow to core-shell and dense nanoparticle morphologies, bimodal pore sizes, and surface chemistries. The resulting Gemini-directed aminated mesoporous silica nanoparticles have excellent carbon dioxide adsorption capacities and antimicrobial properties against Escherichia coli. Our results provide an enhanced understanding of the structure formation of multiscale mesoporous inorganic materials that are desirable for numerous applications such as carbon sequestration, water remediation, and biomedical-related applications.

Characterization of biochar produced from Al Ghaf Tree for CO2 Capture

Climate change, global warming, and rise in water levels are environmental problems caused by the high emissions of greenhouse gases, and the most harmed one is carbon dioxide. Biochar is a material produced by thermochemical conversions with oxygen-depleted conditions of organic materials, and this process calls pyrolysis. Recently, it has been evaluated as a carbon dioxide capture, and its porous structure, structural properties, and production methods are easy. Al Ghaf (Prosopis cineraria) tree is one of the United Arab Emirates’ national trees with a wide range of intriguing properties, including high nutritional value, medicinal/pharmaceutical potential, and biosorption. This paper focuses on the biochar synthesized from three parts of the Al Ghaf tree: leaves, roots, and branches, to determine which part can achieve the maximum carbon dioxide capture. The ability of the produced biochar to capture carbon dioxide was tested through direct gas–solid​ interaction inside an integrated fluidized bed reactor. The carbon dioxide adsorption capacity was expressed by two methods related to (a) the loaded biochar mass and (b) the total amount of carbon dioxide fed to the reactor. The carbon dioxide adsorption capacity results concerning the loaded mass were 6.88%, 5.50%, and 3.63% for leaves, roots, and branches, respectively. At the same time, the results based on the total amount of carbon dioxide fed were 65.5%, 58.7%, and 37.7% for leaves, roots, and branches, respectively. Such results were confirmed by the physicochemical characteristics of the synthesized biochar using Scanning Electron Microscopy with Energy Dispersive X-ray Analysis, Thermogravimetric analysis (TGA), and X-ray diffraction analysis. Al Ghaf tree requires further study and inquiry to identify the most appropriate applications.

Copper-doped activated carbon from amorphous cellulose for hydrogen, methane and carbon dioxide storage

The transition away from fossil fuel and ultimately to a carbon-neutral energy sector requires new storage materials for hydrogen and methane as well as new solutions for carbon capture and storage. Among the investigated adsorbents, activated carbons are considered especially promising because they have a high specific surface area, are lightweight, thermally and chemically stable, and easy to produce. Moreover, their porosity can be tuned and they can be produced from inexpensive and environmentally friendly raw materials. This study reports on the development and characterization of activated carbons synthesized starting from amorphous cellulose with and without the inclusion of copper nanoparticles. The aim was to investigate how the presence of different concentrations of metal nanoparticles affects porosity and gas storage properties. Therefore, the research work focused on synthesis and characterization of physical and chemical properties of pristine and metal-doped activated carbons materials and on further investigation to analyze their hydrogen, methane and carbon dioxide adsorption capacity. For an optimized Cu content the microporosity is improved, resulting in a specific surface area increase of 25%, which leads to a H2 uptake (at 77 K) higher than the theoretical value predicted by the Chahine Rule. For CH4, the storage capacity is improved by the addition of Cu but less importantly because the size of the molecule hampers easy access of the smaller pores. For CO2 a 26% increase in adsorption capacity compared to pure activated carbon was achieved, which translated with an absolute value of over 48 wt% at 298 K and 15 bar of pressure.

The Prospects of Clay Minerals from the Baltic States for Industrial-Scale Carbon Capture: A Review

Carbon capture is among the most sustainable strategies to limit carbon dioxide emissions, which account for a large share of human impact on climate change and ecosystem destruction. This growing threat calls for novel solutions to reduce emissions on an industrial level. Carbon capture by amorphous solids is among the most reasonable options as it requires less energy when compared to other techniques and has comparatively lower development and maintenance costs. In this respect, the method of carbon dioxide adsorption by solids can be used in the long-term and on an industrial scale. Furthermore, certain sorbents are reusable, which makes their use for carbon capture economically justified and acquisition of natural resources full and sustainable. Clay minerals, which are a universally available and versatile material, are amidst such sorbents. These materials are capable of interlayer and surface adsorption of carbon dioxide. In addition, their modification allows to improve carbon dioxide adsorption capabilities even more. The aim of the review is to discuss the prospective of the most widely available clay minerals in the Baltic States for large-scale carbon dioxide emission reduction and to suggest suitable approaches for clay modification to improve carbon dioxide adsorption capacity.

Measurement of carbon dioxide adsorption capacity on selected Turkish lignites

In this work, CO2 adsorption capacities of samples from the four coal (lignite) basins: Soma, Tuncbilek, Tekirdag-Saray and Afsin-Elbistan were experimentally determined at 313.15 K using the volumetric method. Four adsorption models, namely: modified Langmuir, modified Langmuir+k, modified Dubinin-Radushkevich (DR) and modified DR +k models, were used to fit experimental data. The modified DR model was found to be the best fit with an average relative error of less than ±6%. The results show that Soma and Tuncbilek samples have the highest maximum adsorption capacities (nmax) as 1.95 mmol/g and 1.90 mmol/g, respectively. A positive correlation between nmax and fixed carbon content of the samples has been observed. Furthermore, using maximum adsorption capacity values, the maximum CO2 storage capacities of the four lignite basins were determined to be: 62.1 Mt CO2 for Soma, 17.73 Mt CO2 for Tuncbilek, 4.91 Mt CO2 for Tekirdag-Saray and 29.89 Mt CO2 for Afsin-Elbistan. It was estimated that the Soma lignite seam could store the CO2 emissions from a theoretical 100 MW coal power plant for about 102 years, Tuncbilek for about 29 years, Tekirdag-Saray for about 8 years, and Afsin-Elbistan for 49 years.

Significance of extra-framework monovalent and divalent cation motion upon CO2 and N2 sorption in zeolite X

Experimental observations and the GCMC (Grand Canonical Monte Carlo) simulations with fixed and mobile cations in their cavities have been used to study nitrogen and carbon dioxide sorption in divalent cation (Ca, Sr, and Ba) exchanged Zeolite X. Simulations of carbon dioxide and nitrogen adsorption isotherms and the heat of adsorption in divalent cation exchanged zeolite X produced results that were similar to those found in experimental results. Both experimental and simulated isotherms showed that carbon dioxide adsorption capacity is saturated at lower pressure with high adsorption capacity than the nitrogen isotherm in all zeolite samples. In the order of electronegativity of the extra-framework cations, the isosteric heat of sorption results show that carbon dioxide as well as nitrogen molecules interact more with divalent metal ion exchanged zeolites. Simulations of carbon dioxide and the nitrogen sorption in zeolite -X revealed that the mobile extra-framework cations in the cages of zeolite X had a significant advantage over zeolite molecular sieves in the separation process. The simulation with mobile cations can be a good tool for developing selective and purposeful zeolite-based adsorbents by knowing the cation position and its migration upon the adsorption of various gases.

Predicting carbon dioxide adsorption capacity on types 13X and 5A zeolites using artificial neural network modeling

Predicting carbon dioxide adsorption capacity on types 13X and 5A zeolites using artificial neural network modeling

Preparation of Nitrogen-Doped Cellulose-Based Porous Carbon and Its Carbon Dioxide Adsorption Properties.

Nitrogen-doped cellulose-based porous carbon materials were obtained by hydrothermal method and KOH chemical activation together with melamine as a nitrogen-doping precursor. The effects of hydrothermal temperature on the microstructure and surface morphology of the products were mainly studied. Also, the carbon dioxide adsorption capacity of the prepared porous carbon was investigated. It was found that when the hydrothermal carbonization temperature was 270 °C and the mass ratio of cellulose and melamine was 1:1, the largest micropore specific surface area of 1703 m2·g–1 and micropore volume of 0.65 cm3·g–1 were obtained, with a nitrogen-doping composition of 1.68 atom %. At the temperature of 25 °C and under the pressure of 0.1, 0.2, 0.3, and 0.4 MPa, the adsorption amount of CO2 was 1.56, 3.79, 5.42, and 7.34 mmol·g–1, respectively. Also, the adsorption process of CO2 was in good accordance with the Freundlich isotherm model.

Zeolitic imidazolate frameworks based porous liquids for promising fluid selective gas sorbents

A kind of zeolitic imidazolate frameworks based porous liquids (e.g., ZIF-8 PLs) with permanent porosity was successfully fabricated by using amine-functionalized ZIF-8 nanoparticles (i.e., ZIF8-A) as the porous fillers and monoglycidyl ether terminated poly(dimethylsiloxane) (i.e., PDMS) as the hindered solvent, respectively. Those ZIF-8 PLs were homogenous and stable at room temperature because of the liquid-particle interaction derived from the epoxy-amine reaction. In addition, those ZIF-8 PLs have larger gas adsorption abilities than their reference hindered solvent because the well-preserved permanent porosity in ZIF-8 PLs could act as void space for gas accommodation. More importantly, those ZIF-8 PLs also show much higher propane adsorption capacity than both of carbon dioxide and nitrogen gas adsorption capacities under the same condition, suggesting that they could function as a kind of promising candidates for fluid selective gas sorbents.

Production and characterization of bamboo-based activated carbon through single-step H3PO4 activation for CO2 capture.

Bamboo is the fastest-growing plant and is abundant in Malaysia. It is employed as a starting material for activated carbon production and evaluated for its potential in CO2 capture. A single-stage phosphoric acid (H3PO4) activation is adopted by varying the concentrations of H3PO4 between 50 and 70 wt.% at a constant temperature and holding time of 500°C and 120 min, respectively. The bamboo-based activated carbons are characterized in terms of product yield, surface area, and porosity, as well as surface chemistry properties. Referring to the experimental findings, the prepared activated carbons have BET surface area of >1000 m2 g-1, which implies the effectiveness of the single-stage H3PO4 activation. Furthermore, the prepared activated carbon via 50 wt.% H3PO4 activation shows the highest BET surface area and carbon dioxide (CO2) adsorption capacity of 1.45 mmol g-1 at 25°C/1 bar and 9.0 mmol g-1 at 25°C/30 bar. With respect to both the characterization analysis and CO2 adsorption performance, it is concluded that bamboo waste conversion to activated carbon through H3PO4 activation method is indeed promising.

Development of facile synthesized mesoporous carbon composite adsorbent for efficient CO2 capture

Amine-functionalized adsorbents show broad application prospects in the field of flue gas CO2 capture. However, the development of support materials with excellent CO2 capture performance and facile synthesis method is still a challenge. In this work, mesoporous carbon (MC) with the ultra large pore volume of 3.1 cm3/g is synthesized by direct carbonization of the mixture of adipic acid and zinc powder without further chemical/physical activation process. The synthesized MC was then impregnated with tetraethylenepent amine (TEPA) to prepare the adsorbent. The formed ultra large pore volume and abundant mesopores structure could promote adsorption active site dispersion, thereby improving CO2 adsorption performance. As a result, the MC support loaded with 80 wt% TEPA exhibits a large CO2 capture amount of 5.3 mmol/g at 75 ℃ with 15 vol%CO2. In addition, the carbon dioxide adsorption capacity is only 8.1 % less than that of the fresh adsorbent after 10 adsorption cycles, indicating that this adsorbent has excellent cycling stability. Noted that the synthesis of MC significantly improves the CO2 adsorption performance while simplifying the support material preparation process. Thus, it is believed that the MC material is promising adsorbent support for highly efficient CO2 capture.

Efficiency increase in hypercrosslinked polymer based on polystyrene in CO2 adsorption process

In this investigation, a hypercrosslinked polymer based on polystyrene as an adsorbent was used for CO2 adsorption. Design of experiment with response surface methodology is considered to optimize the synthesis parameters for obtaining the maximum carbon dioxide adsorption capacity. The independent parameters including the crosslinker amount (mmol), synthesis time (h) and catalyst type (FeCl3 and AlCl3) and adsorption capacity (mg/g) are considered as the dependent parameter in design of experiment method. The optimum values of crosslinker amount, synthesis time, and catalyst type to maximize adsorption capacity achieved 17.7 mmol, 14.6 h, and FeCl3, respectively. Additionally, isotherm and kinetic modeling were carried out to determine the adsorbent behavior. The results showed that Hill and Elovich models have a better precision between other isotherm and kinetic models. Finally, thermodynamic modeling was accomplished using the optimized adsorbent and the results show that physisorption is the main of CO2 adsorption by polystyrene-based adsorbent. The values of − 13.498 kJ/mol, − 0.018 kJ/mol.K, and − 8.224 kJ/mol were obtained for enthalpy differences, entropy differences, and Gibbs free energy change at 293 K and 5 bar, respectively.

Aminopropyltriethoxysilane functionalized MCM-41 and SBA-15 nanostructured materials for carbon dioxide adsorption

The design of effective CO2 capture materials is a current challenge. Here, we report the synthesis of aminosilanes-functionalized MCM-41 and SBA-15 materials with high efficiency toward carbon dioxide adsorption. The functionalization of the mesoporous silicas involves a post-synthesis method by impregnation with 3-aminopropyltriethoxysilane. The carbon dioxide adsorption capacities for the samples were carried out under ambient pressures. The results evidenced that aminosilanes with a terminal amine were functionalized through covalent coupling of this group onto the channels' surface in the ordered mesoporous silica. It means that the amine is anchored on the surface of the largest pores of the MCM-41 and SBA-15 supports. The Lagergren kinetic model evidenced the enhanced carbon dioxide adsorption capacity and stability of the functionalized ordered mesoporous molecular sieves.

Empty cotton boll crop-residue and plastic waste valorization to bio-oil, potassic fertilizer and activated carbon – A bio-refinery model

Empty cotton boll and plastic waste (@ 5% w/w) were slow pyrolyzed in a fixed bed pilot scale reactor at 500 °C in vacuum. The proposed bio-refinery model involves: (1) application of bio-oil as alternative fuel in existing engine facility, (2) water leaching of bio-char followed by synthesis of potassic fertilizer, and (3) chemical activation of spent char to porous carbon. Thorough investigation of moisture free bio-oil fuel properties supported its applicability in the engine. Moisture free bio-oil was blended with commercial gasoline in proportions of 10–30% (v/v). The effect of engine functioning parameters: compression ratio, engine load and blend proportion on engine performance and emission was optimized using response surface methodology. Almost 93 wt% of water leachable potassium available in the bio-char was leached out via two stage counter current leaching. Route of selective precipitation using tartaric acid converted ∼98 wt% of potassium available in leachate to potassium nitrate. Porous carbon with surface area of 1381.40 m2/g was derived via chemical activation of spent char at 700 °C in nitrogen atmosphere. The porous carbon showed carbon-dioxide adsorption capacity of 5.1 mmol/g at 25 °C and 1 atm pressure.