Presence Of CO2 Gas Research Articles

Configuration rearrangement of squalane induced by carbon dioxide dissolution: A molecular simulation study

Squalane has emerged as a desirable absorbent material for carbon capture, utilization, and storage solutions due to its tunable sorption properties, microscopic structures, and cost-effectiveness in response to the increasing demand. Moreover, a thorough understanding of the fundamental characteristics of hydrocarbons and dissolved gases involved in the Fischer–Tropsch industrial synthesis processes is also essential for researching industrial purification and separation. However, these macromolecules may experience varying degrees of induced alterations in their structural rearrangement when absorbing absorbates, which impacts the performance indicators of squalane. This study examined the solubility characteristics of absorbents made from squalane and their interaction with gaseous CO2 molecules. The perturbed chain statistical associated fluid theory (PC–SAFT) was employed to comprehensively evaluate the macroscopic thermodynamic experimental density and solubility data. Simultaneously, the Monte Carlo (MC) simulation approach was utilized to investigate the rearrangement and swelling features of the squalane chain induced by the presence of CO2 gas in a broad spectrum of temperature and pressure conditions. This work indicated that elevated temperatures increased flexibility in the molecular structure of squalane, leading to a more pronounced spatial dispersion, while higher pressures may lead to spatial homogeneity and enhanced capacity for carrying additional CO2 molecules. The examples and methodologies presented demonstrate the effectiveness of molecular simulations in comprehending absorption–based phenomena at an atomistic and molecular level and offer essential guidance in forecasting the potential for separation, storage, or catalytic.

Rapid and dual optical CO2-responsive polydimethylsiloxane elastomer with fluorinated cyanine dye.

We found that our optically CO2-responsive polydimethylsiloxane (PDMS) elastomer rapidly and reversibly underwent both visible and fluorescent color changes in the presence of CO2 gas. Unlike conventional optically CO2-responsive polymeric materials, it functions in totally dry gaseous conditions. The visible color and fluorescence of the elastomer sheet change after only 1 min of exposure to CO2, and the sheet exhibits excellent repeatability in terms of color switching that persists for at least 20 times.

Determination of Kinematic Viscosity of Mg(ClO4)2 and KOH Brines Saturated with CO2 at Sub-Zero Temperatures.

The current race for space exploration has hastened the development of electrochemical technologies for the in-situ utilisation of planetary resources for the synthesis of vital chemicals such as O2 and fuels. Understanding the physicochemical properties, such as the density and kinematic viscosity, of aqueous solutions is essential for the design of electrochemical devices for the electrolysis of water and CO2, particularly at low temperatures. The density and kinematic viscosity of highly concentrated Mg(ClO4)2 and KOH solutions have been determined, both at low temperatures and in the presence of CO2 gas. It was found that, for all of the solutions, independent of the concentration or nature of the electrolyte, as the temperature was decreased to 255 K, the density and the viscosity of the solutions increased. Upon saturation with CO2, no significant change to the density and viscosity of Mg(ClO4)2, at all of the temperatures measured, was observed. Conversely, the CO2 saturated solutions of KOH showed significant changes in density and viscosity at all temperatures, likely due to the formation of carbonates. The effects of these changes on the diffusion coefficient for dissolved CO2 is also discussed.

Geochemical Effects on Storage Gases and Reservoir Rock during Underground Hydrogen Storage: A Depleted North Sea Oil Reservoir Case Study

In this work, geochemical modelling using PhreeqC was carried out to evaluate the effects of geochemical reactions on the performance of underground hydrogen storage (UHS). Equilibrium, exchange, and mineral reactions were considered in the model. Moreover, reaction kinetics were considered to evaluate the geochemical effect on underground hydrogen storage over an extended period of 30 years. The developed model was first validated against experimental data adopted from the published literature by comparing the modelling and literature values of H2 and CO2 solubility in water at varying conditions. Furthermore, the effects of pressure, temperature, salinity, and CO2% on the H2 and CO2 inventory and rock properties in a typical sandstone reservoir were evaluated over 30 years. Results show that H2 loss over 30 years is negligible (maximum 2%) through the studied range of conditions. The relative loss of CO2 is much more pronounced compared to H2 gas, with losses of up to 72%. Therefore, the role of CO2 as a cushion gas will be affected by the CO2 gas losses as time passes. Hence, remedial CO2 gas injections should be considered to maintain the reservoir pressure throughout the injection and withdrawal processes. Moreover, the relative volume of CO2 increases with the increase in temperature and decrease in pressure. Furthermore, the reservoir rock properties, porosity, and permeability, are affected by the underground hydrogen storage process and, more specifically, by the presence of CO2 gas. CO2 dissolves carbonate minerals inside the reservoir rock, causing an increase in the rock’s porosity and permeability. Consequently, the rock’s gas storage capacity and flow properties are enhanced.

Synthesis of g-C3N4/NiO-carbon microsphere composites for Co-reduction of CO2 by photocatalytic hydrogen production from water decomposition

In this paper, a g-C3N4/NiO/corn straw derivative carbon microsphere composite photocatalyst was successfully prepared. Photoelectric studies show that a heterojunction was formed between g-C3N4 and NiO nanosheets, and the graphitized carbon microspheres were successfully modified on g-C3N4 and NiO nanosheets. The heterostructure between g-C3N4 and NiO works synergistically with the conductivity of carbon microsphere, resulting in H2 production and CO2 reduction in photocatalysis. Photocatalytic experiments show that the photocatalytic performance of g-C3N4/NiO/carbon microsphere composite is enhanced, and the highest H2 production rate was 36–58 times higher than that of pure g-C3N4. In the presence of CO2 gas, H2 production and CO2 reduction occur simultaneously. The possible mechanism of H2 production combined with CO2 reduction photocatalysis is analyzed from the perspective of thermodynamics and kinetics. The g-C3N4/NiO/carbon microsphere composite has a stronger H2 evolution performance than CO2 reduction performance. The change in free energy (ΔG) for the conversion of CO* to free CO gas is 0.52 eV, and CO release is the key step affecting the synergistic reduction of CO2 by H2. This study provides new strategies for the synergistic reduction of CO2 by photocatalytic technology for H2 production.

Optimization and physicochemical studies of alumina supported samarium oxide based catalysts using artificial neural network in methanation reaction

Developed countries are increasing their demand for natural gas as it is an industrial requirement for fuel transportation. Most of modern society relies heavily on vehicles. However, the presence of CO2 gas has led to the categorization of sour natural gas which reduces the quality and price of natural gas. Therefore, the catalytic methanation technique was applied to convert carbon dioxide (CO2) to methane (CH4) gas and reduce the emissions of CO2 within the environment. In this study, samarium oxide supported on alumina doped with ruthenium and manganese was synthesized via wet impregnation. X-ray diffraction (XRD) analysis revealed samarium oxide, Sm2O3 and manganese oxide, MnO2 as an active species. The reduction temperature for active species was at a low reaction temperature, 268.2oC with medium basicity site as in Temperature Programme Reduction (TPR) and Temperature Programme Desorption (TPD) analyses. Field Emission Scanning Electron Microscopy (FESEM) analysis showed an agglomeration of particle size. The characterised potential catalyst of Ru/Mn/Sm (5:35:60)/Al2O3 (RMS 5:35:60) calcined at 1,000oC revealed 100% conversion of CO2 with 68.87% CH4 formation at the reaction temperature of 400oC. These results were verified by artificial neural network (ANN) with validation R2 of 0.99 indicating all modelling data are acceptable.

Effect of polythiophene thickness on hybrid sensor sensitivity

Abstract In recent years, hybrid structures have attracted wide consideration because they generate new very interesting properties. In this study, a hybrid gas sensor was developed using a simple fabrication process from the combination of porous silicon (PSi) and polythiophene (PTh). The study of the effect of electropolymerization rate and film thickness of PTh on the sensitivity and the stability of sensor was realized at room temperature. PSi was formed by electrochemical anodization, and it is an interesting material for sensing applications due to its high surface area. However, to avoid its degradation and to preserve its properties over the time, PSi surface was functionalized electrochemically with PTh subsequently to thermal oxidation. PTh as a conductive polymer is known for its high sensitivity and stability to environmental change. Several thicknesses of PTh have been electropolymerized onto the oxidized PSi surface to determine the best conditions for developing a sensitive and stable sensor. PTh thickness was controlled by the number of applied voltammogram cyclic. The characterizations of the different elaborated surfaces were carried out by Fourier transform infrared spectroscopy, scanning electron microscopy, cyclic voltammetry, contact angle, and secondary ion mass spectrometry. Finally, we studied the sensitivity, the response time, and the stability of PSi/PTh structures with different PTh thicknesses in the presence of CO2 gas and under cigarette smoke, by performing electrical characterizations, at room temperature.

Thermodynamics and Chemical Behavior of Uranyl Superoxide at Elevated Temperatures.

Understanding the alteration mechanisms of UO2-based nuclear fuel has a range of practical implications for both short- and long-term storage of spent fuel rods and environmental ramifications for the mobility of radioactive material at the Chernobyl and Fukushima sites. The major identified alteration phases on the surface of nuclear waste are analogues of schoepite UO3·2H2O, studtite UO2(O2)·4H2O, rutherfordine UO2CO3, and čejkaite Na4UO2(CO3)3. While α-radiolysis has been shown to cause the ingrowth of uranyl peroxide alteration phases, the prevalence of uranyl carbonate phases on solid waste forms has not been mechanistically explained to date, especially since the alteration chemistry is largely affected by the high temperatures of the spent nuclear material. Herein, we demonstrate the first mechanistic link between the formation of the uranyl superoxide (KUPS-1) phase, its reactivity at temperature ranges relevant to the spent nuclear fuel (40-350 °C), and its thermodynamic transformation into a potassium uranyl carbonate mineral phase, agricolaite K4[UO2(CO3)3], using thermogravimetric analysis, calorimetry, vibrational spectroscopy, and powder X-ray diffraction techniques. The thermodynamics data reveal the metastability of the uranyl superoxide KUPS-1 phase through decomposition of the hydrogen peroxide within the solid-state lattice. Increasing the temperature does not result in the breakdown of the superoxide anion bound to the uranyl cation but instead enhances its reactivity in the presence of CO2 gas, resulting in potassium carbonate phases at intermediate temperatures (150 °C) and in uranyl carbonate phases at higher temperatures (350 °C).

Thermally activated epoxy-functionalized carbon as an electrocatalyst for efficient NOx reduction

Large toxic emissions like nitrogen and sulphur oxides (NOx, SO2) are causing serious environmental and health issues. Catalytic reduction of NOx and SOx into friendly gases is considered one of the best approaches. However, regeneration of catalyst, higher bond-dissociation energy for NOx,i.e., 150.7 kcal/mol, escape of intermediate gas (N2O, a greenhouse gas) with treated flue-gas, and limited activity of catalyst remains a great challenge. Here, a cheap, binderless naturally-extracted bass-wood thin carbon electrode (TCE) was fabricated, which shows excellent catalytic activity towards NOx reduction. The bass-wood carbonization was carried out at 900 °C followed by thermal activation in the presence of CO2 gas at 750 °C. The thermal activation resulted in increased epoxy groups on the surface of the TCE and enhancement in the surface area as well as the degree of graphitization. The TCE unique 3D strongly inter-connected network through hierarchical micro/meso/macro pores that allow large electrode/electrolyte interface. Owing to these characteristics, the TCE exhibited excellent catalytic efficiency towards NOx (∼83.3%) under ambient conditions and enhanced catalytic response around neutral pH and sulphite exposure as well as excellent stability up to 168 h. Moreover, a temperature-dependent activity trend was found where the highest catalytic activity was achieved at 80 °C beyond which the electrolyte became evaporative and resulted in performance decrease. The designed electrocatalyst is low-cost, sustainable and showed great potential for effective NOx-reduction, which might be used for NOx abatement at large scale..

Interparticle cycloaddition reactions for morphology transition of coumarin-functionalized stimuli-responsive polymer nanoparticles prepared by surfactant-free dispersion polymerization

Stimuli-responsive polymer nanoparticles were synthesized by surfactant-free dispersion polymerization of styrene and 2-(dimethylamino)ethyl methacrylate (DMAEMA) in three different contents of divinylbenzene intraparticle crosslinking agent. Incorporation of the hydrophilic DMAEMA comonomer during the polymerization yielded pH-responsive nanogels with a higher size than the polystyrene nanoparticles. Surface of the nanoparticles was decorated with 7-hydroxyl-4-methylcoumarin (HMC) via an esterification reaction to yield stimuli-responsive fluorescent nanogels. The monodispersed polymer nanoparticles with spherical morphology were turned into chain-like coupled structures because of interparticle cycloaddition reactions between the surface HMC moieties upon UV irradiation, as shown by scanning and transmission electron microscopies. Dimerization of the HMC-functionalized nanoparticles was investigated by ultraviolet–visible spectrophotometer and fluorescence spectroscopy. Size and its distribution for the nanoparticles before and after light irradiation were determined using dynamic light scattering. From a different view, decreasing the intraparticle crosslinking density and also purging the colloidal dispersions with CO2 were resulted in a higher mean particle size. Variation of particle size by purging CO2 and consequently at different pH values was resulted in different fluorescence characteristics. Therefore, these stimuli-responsive fluorescent nanoparticles were finally used as a pH indicator in the presence of CO2 gas or even at different pH values using fluorescence spectroscopy.

Pilot Test of pH Triggered Polymer Sealant for CO2 Storage

Wellbore integrity is a critical subject in oil and gas production and CO2 storage. Successful subsurface deposition of various fluids, such as CO2, depends on the integrity of the storage site. In a storage site, injection wells and pre-existing wells might leak due to over-pressurization, mechanical/chemical degradation, and/or a poor cement job, thus reducing the sealing capacity of the site. Wells that leak due to microannuli or cement fractures on the order of microns are difficult to seal with typical workover techniques. We tested a novel polymer gelant, originally developed for near borehole isolation, in a pilot experiment at Mont Terri, Switzerland to evaluate its performance in the aforementioned scenario. The polymer gel sealant was injected to seal a leaky wellbore drilled in the Opalinus Clay as a pilot test. The success of the pH-triggered polymer gel (sealant) in sealing cement fractures was previously demonstrated in laboratory coreflood experiments [1-3]. pH-sensitive microgels viscosify upon neutralization in contact with alkaline cement to become highly swollen gels with substantial yield stress that can block fluid flow. The leaky wellbore setup was prepared by heating-cooling cycles to induce leakage pathways in the cased and cemented wellbore. The leakage pathways are a combination of fractures in the cement and microannuli at the cement-formation interface. The exact nature of these leakage pathways can be determined by over-coring at the end of the experiment life. We used polyacrylic acid polymer (sealant) to seal these intervals. The process comprises of three stages: (1) injection of a chelating agent as the preflush to ensure a favorable environment for the polymer gel, (2) injection of polymer solution, and (3) shut-in for the polymer gelation. Then, we evaluated the short-/long-term performance of the sealant in withholding the injected fluids (formation brine and CO2 gas). The novel sealant was successfully deployed to seal the small aperture pathways of the borehole at the pilot test. We conducted performance tests using formation brine and CO2 gas to put differential pressure on the polymer gel seal. Pressure and flow rate at the specific interval were monitored during and after injection of brine and CO2. Results of performance tests after polymer injection were compared against those in the absence of the sealant. Several short-term (4 min) constant-pressure tests at different pressure levels were performed using formation brine, and no significant injection flow rate (rates were below 0.3 ml/min) was observed. The result shows more than a ten-fold drop in the injection rate compared to the case without the sealant. The polymer gel showed compressible behavior at the beginning of the short-term performance tests. Our long-term (1-week) test shows even less injectivity (~ 0.15 ml/min) after polymer gelation. The CO2 performance test shows only 3 bar pressure dissipation overnight after injection compared to an abrupt loss of CO2 pressure in the absence of polymer gel. Sealant shows good performance even in the presence of CO2 gas with high diffusivity and acidity. Pilot test of our novel sealant proves its competency to mitigate wellbore leakage through fractured cement or debonded microannuli, where other remedy techniques are seldom effective. The effectiveness of the sealing process was successfully tested in the high-alkaline wellbore environment of formation brine in contact with cement. The results to date are encouraging and will be further analyzed once over-coring of the wellbore containing the cemented annulus occurs. The results are useful to understand the complexities of the cement/wellbore interface and adjust the sealant/process to sustain the dynamic geochemical environment of the wellbore.

Comparison of photosynthetic carbon fixation of Nannochloropsis oceanica cultivated with carbon suppliers: CO2, NaHCO3 and CH3OH

To increase the carbon fixation efficiency of Nannochloropsis oceanica cultivated with industrial flue gas and wastewater, typical CO2 suppliers of methanol, NaHCO3 and CO2 were combined with 15 % CO2 flue gas, then compared for their effects on N. oceanica intracellular metabolic and biological regulation. In the presence of CO2 gas with and without its ionized acid (HCO3−), microalgal growth was inhibited due to carbon transport-dependent ion transfer and balance. In a weakly acidic environment, growth inhibition was due to cell apoptosis, while in a weakly alkaline environment this was led to cell division inhibition by a decrease of translation initiation factors and carbon fixation stagnation by mass closure of photosynthetic reaction centers. When methanol was combined with 15 % CO2 gas, less negative effects on N. oceanica growth due to changes in the CO2/HCO3- equilibrium. The presence of methanol increased light-dependent reactions by providing sufficient substrates for photosynthetic pigment synthesis through enhanced glycolysis. Total carbon fixation was further increased by higher rates of cell division. The biomass yield and carbon fixation efficiency of N. oceanica grown with methanol and 15 % CO2 was 8.4-fold, and 78.3 % greater, respectively, than that of N. oceanica grown with only 15 % CO2 gas.

Origin, diversity and geothermal potentiality of thermal and mineral waters in Vrnjačka Banja, Serbia

Based on the results of 15 years of research on the physical and chemical parameters of 11 occurrences of thermal and mineral water in the extended area of the spa town of Vrnjacka Banja, diverse hydrochemical types of water have been identified, originating from different lithological formations (serpentinite, schist, marble, etc.). Currently, the total amount of abstracted thermo-mineral water is close to 70 L/s, with water temperatures up to 33.8 °C. However, interpretation of collected data indicates that the chemical composition of the mineral water is not exclusively related to the mineralogical composition of the host rock, i.e., aquifer material. To better understand the genesis of these waters, multivariate statistical analysis was undertaken in combination with hydrochemical interpretation of different ionic ratios. This approach revealed the existence of three distinct clusters of thermal and mineral waters: (1) low temperature, low mineral content and mild alkaline; (2) slightly acidic, with a moderate mineral content and elevated iron and fluoride concentrations; and (3) thermal, rich in CO2, with elevated mineral content and iron, manganese and fluoride concentrations. Two primary hydrogeochemical processes, which influence the composition of the thermo-mineral waters, were also identified: dissolution of serpentinite rocks and dissolution of schists, both enhanced by the presence of CO2 gas, circulating through fault zones. Estimates of available geothermal energy suggest a significant potential for expanding current uses of thermal waters of this most popular spa center in Serbia.

Study The Corrosion Behavior of Carbon Steel in Presence Of CO2 Gas in Oil Pipe Lines

The current work is the study of corrosion behaveior of carbon steel, in naturally aerated (3.5%wt NaCl) solution. A rotating cylinder electrode (RCE) system was used to produce conditions of turbulent flow, polarization experiments were conducted at various temperature and various rotating speed at each temperature.Similar experiments were carried out using CO2 gas at (32 ml/sec) flow rate.Corresponding experiments by weight loss were carried out in (3.5%wt NaCl) solution with Kerosene + 10% V salt solution and Gas oil + 10% V salt solution at 328k and (0, 400) r.p.m .Similar experiments were carried out in kerosene + 10% V salt solution at (298, 308 and 318)K and rotating speed (0) r.p.m at each temperature.Other experiments were carried out in pure kerosene at temperature (298 and 318)K and speed (0) r.p.m. All experiments were carried out with and with out CO2 gas .The results indicate that the corrosion rate of carbon steel is increasing70% with CO2 gas

A gas-plastic elastomer that quickly self-heals damage with the aid of CO2 gas

Self-healing materials are highly desirable because they allow products to maintain their performance. Typical stimuli used for self-healing are heat and light, despite being unsuitable for materials used in certain products as heat can damage other components, and light cannot reach materials located within a product or device. To address these issues, here we show a gas-plastic elastomer with an ionically crosslinked silicone network that quickly self-heals damage in the presence of CO2 gas at normal pressures and room temperature. While a strong elastomer generally exhibits slow self-healing properties, CO2 effectively softened ionic crosslinks in the proposed elastomer, and network rearrangement was promoted. Consequently, self-healing was dramatically accelerated by ~10-fold. Moreover, self-healing was achieved even at −20 °C in the presence of CO2 and the original mechanical strength was quickly re-established during the exchange of CO2 with air.

Trends in the Catalytic Activity of Hydrogen Evolution during CO2 Electroreduction on Transition Metals

During CO2 electroreduction (CO2R), the hydrogen evolution reaction (HER) is a competing reaction. We present a combined experimental and theoretical investigation of the HER activity of transition metals under CO2R conditions. Experimental HER polarization curves were measured for six polycrystalline metal surfaces (Au, Ag, Cu, Ni, Pt, and Fe) in the presence of CO2 gas. We found that the HER activity of the transition metals is significantly shifted, relative to the CO2-free case. Density functional theory (DFT) calculations suggest that this shift arises from adsorbate–adsorbate interactions between *CO and *H on intermediate and strong binding metals, which weakens the *H binding energy. Using a simple model for the effect of *CO on the *H binding energy, we construct an activity volcano for HER in the presence of CO2 gas that is consistent with experimental trends. The significant changes in HER activity in the presence of CO2 gas is an important consideration in catalyst design and could help develo...

Preparation and characterization of a TiO2-cis photocatalyst for CO2 reduction and utilization.

With the overabundance of detrimental gases in the atmosphere such as carbon dioxide, efforts are being made to not only remove them but to utilize them in artificial photosynthetic pathways. Titanium dioxide nanoparticles are well-known photocatalytic materials for water splitting and CO2 reduction. By introducing semiconductor nanocrystals, the electronic structure of the TiO2 may be altered to improve efficiency and selectivity for synthetic routes. Wet chemistry and inert atmospheric methods were used to synthesize copper indium sulfide (CIS) quantum dots and TiO2 nanomaterials. Characterization results from UV-Vis, fluorescence, and infrared spectroscopy will be presented. A vacuum system, high power arc lamp, and infrared spectroscopy were employed to investigate potential photosynthesis using the TiO2-CIS in the presence of CO2 gas and H2O vapor. Results from these experiments will be provided.

Preparation, characterization and CO2 gas sensitivity of Polyaniline doped with Sodium Superoxide (NaO2)

The sodium superoxide was prepared in single step method by heating sodium nitrate (NaNO3) in oxygen rich environment. The PANi/NaO2 composites were prepared using Ex-situ technique range from 5–20wt.%. The crystallinity and structure morphology of the PANi/ NaO2 composite films were characterized by X-ray diffraction, Scanning electron microscopy and Fourier transform infrared spectroscopy respectively. The sensor response was estimated by the change in electrical resistance of sensor in presence of CO2 gas. The sensor response and selectivity for pure PANi and doped PANi/NaO2 sensors as a function of concentration of CO2 at room temperature has been systematically studied. The sensors show better performance towards the CO2. A significant sensitivity and fast response toward CO2 observed for the 20wt.% PANi/NaO2 composite film. The sensing response curve assign to transition from n-type to p-type behavior of samples.

Proton-Conducting Nanocrystalline Ceramics for High-Temperature Hydrogen Sensing

The proton-conductive doped ceramic materials, including SrCe0.95Tb0.05O3−δ (SCTb), SrCe0.8Zr0.1Y0.1O3−δ (SCZY), and SrZr0.95Y0.05O3−δ (SZY), are synthesized in the forms of nanoparticles and nanocrystalline thin films on sapphire wafers and long-period grating (LPG) fibers. The H2 chemisorption and electrical conductivity of the nanocrystalline SCTb, SCZY, and SZY materials are measured at high temperature with and without the presence of CO2 gas. The resonant wavelength shifts (\( \Updelta \lambda_{{{\text{R,H}}_{ 2} }} \)) of the SCTb, SCZY, and SZY thin-film coated LPGs in response to H2 concentration changes are studied in gas mixtures relevant to coal gasification syngas to evaluate their potential for high-temperature H2 detection. The results show that, at around 773.15 K (500 °C), SCTb has the highest H2 sensitivity but the most severe interferences from impurities such as CO2 and H2S; SZY has the best chemical resistance to impurities but the lowest H2 sensitivity; and SCZY exhibits high H2 sensitivity with reasonable chemical resistance.

Characterization of Physically Activated Acacia mangium Wood-Based Carbon for the Removal of Methyl Orange Dye

In this experiment, Acacia mangium wood was physically activated in the presence of CO2 gas at an activation temperature of 500 ºC for 2 h. The total surface area of the activated carbon was found to be 395.91 m2/g, 81.06% of which was due to micropores. Fourier transform infrared spectroscopy showed that the major functional groups on the surface of activated carbon were carboxylate, hydroxyl, and lactone groups. An isotherm study of methyl orange dye adsorption by the activated carbons was conducted. Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) isotherms were applied to find the adsorption characteristics of the activated carbon. The results showed that the isotherm data followed the Langmuir isotherm with maximum adsorption capacity of 7.54 mg/g at a temperature of 25 °C and an equilibrium time of 48 h. A dimensionless equilibrium constant, RL equal to 0.3280 was also determined to prove that adsorption was favorable but not very effective.