Reaction Kinetics Of Carbon Dioxide Research Articles

Measurement of the Absorption Rates of Carbon Dioxide in Aqueous Solutions of Piperazine and Sulfolane Using the Stopped-flow Technique

With the accelaration of the exploitation of natural gas reservoirs, the efficient removal of contaminants such as CO2, H2S, RSH, and COS is becoming of critical importance. In recent years, there is a growing interest in using amine blends or mixed solvents instead of a single amine for gas sweetening processes. Mixed solvents composed of a chemical solvent and a physical solvent take advantage of the benefits of both physical and chemical absorptions. The study of the absorption kinetics of the mixed solvent are necessary for designing and optimizing the process for removal of CO2 from natural gas, synthesis gas, or reformer gas. As a physical solvent, Sulfolane has excellent stability and low corrosiveness, in addition to a high capability for CO2 absorption. Sulfinol is a comercially successful process used in more than 200 plants and based on the use of Sulfolane as a physical solvent and either Diisopropanolamine (DIPA) or Methyldiethanolamine (MDEA) as chemical solvents. Mixed Sulfolane-based solvents have recently been proposed for post-combustion CO2 capture. In this study, the reaction kinetics of carbon dioxide (CO2) in aqueous solutions of aqueous piperazine (PZ) and an aqueous mixed solvent of (PZ + Sulfolane) were measured using the stopped flow technique resulting in the meaurement of observed pseudo-first-order rate constants (k0) allowing for the calculation of the second-order reaction rate constants (k2). The experiments were carried out over) concentration ranges of (10 to 60) for PZ, and (10 to 40, 10 to 200) (mol/m3) for PZ and Sulfolane, respectively and temperatures ranging from (298.15 to 313.15) K. Results show that the kinetic rates of the mixed solvent (PZ + Sulfolane + Water) were higher than those in aqueous PZ at all temperatures. The reaction kinetics in aqueous mixed solents of (PZ + Sulfolane) in reaction with CO2 increase with increasing temperature and concentration. The Termolecular mechanisms correlated the aqueous mixed systems of (PZ + Sulfolane) successfully. The reaction kinetics increased with the increase in temperature and concentration. The addition of Sulfolane to aqueous PZ resulted in increased absorption rates. Thus, the mixed solvent of PZ, Sulfolane and water can be considered an attractive alternative to aqueous amines for the enhancement of CO2 capture.

Reaction Kinetics of Carbon Dioxide in Aqueous Blends of N-Methyldiethanolamine and L-Arginine Using the Stopped-Flow Technique

: Reduction of carbon dioxide emission from natural and industrial flue gases is paramount to help mitigate its effect on global warming. Efforts are continuously deployed worldwide to develop efficient technologies for CO2 capture. The use of environment friendly amino acids as rate promoters in the present amine systems has attracted the attention of many researchers recently. In this work, the reaction kinetics of carbon dioxide with blends of N-methyldiethanolamine and L-Arginine was investigated using stopped flow technique. The experiments were performed over a temperature range of 293 to 313 K and solution concentration up to one molar of different amino acid/amine ratios. The overall reaction rate constant (kov) was found to increase with increasing temperature and amine concentration as well as with increased proportion of L-Arginine concentration in the mixture. The experimental data were fitted to the zwitterion and termolecular mechanisms using a nonlinear regression technique with an average absolute deviation (AAD) of 7.6% and 8.0%, respectively. A comparative study of the promoting effect of L-Arginine with that of the effect of Glycine and DEA in MDEA blends showed that MDEA-Arginine blend exhibits faster reaction rate with CO2 with respect to MDEA-DEA blend, while the case was converse when compared to the MDEA-Glycine blend.

Reaction kinetics of carbon dioxide with potassium prolinate in water-lean solvents

Water-lean absorbents have potential applications for energy-efficient CO2 capture. In this work, the chemical kinetics of the reaction between carbon dioxide (CO2) and potassium prolinate (ProK) in ethanol, ethylene glycol and water solvents was measured in a stirred cell reactor with a stable gas-liquid interface at temperatures from 275.2 to 285.2 K and ProK molar concentrations up to 2.0 M. The experiments were performed under the pseudo-first-order regime to determine the overall kinetic rate constant (kov) using two-film theory. The results showed that the reaction rates in each polar solvent increase considerably as the increasing ProK concentrations and temperatures. The reaction order was found to be in the range of 1.4–2.0 with respect to ProK concentration, depending on the solvents used. The kinetic results for the reaction in ethanol were also interpreted based on zwitterion mechanism and termolecular mechanism. The calculated from the two proposed models match well with the experimental data.

Reaction Kinetics of Carbon Dioxide with 2-Amino-1-butanol in Aqueous Solutions Using a Stopped-Flow Technique

Carbon capture and management plays an important role in the development of new technologies to mitigate anthropogenic global warming. In this work, for the first time, the kinetics of CO2 with aminobutanol (AB) using a stopped-flow method are presented. The temperature changed from 293 to 313 K for a total amine concentration up to 0.3 mol/L. The kinetics data were analyzed using both zwitterion and termolecular reaction mechanisms with a preference to the zwitterion mechanism. AB was found to react with CO2 (aq) with k2 (M–1 s–1) = 2.93 × 109 exp(−4029.9/T (K)) with an estimated activation energy of 33.51 kJ/mol. Compared to other popular amines, CO2 reaction with aminobutanol has faster kinetics than that of CO2 with diethanolamine (DEA) and 2-amino-2-methyl-1-propanol (AMP) but slower than that with monoethanolamine (MEA). The Bronsted relationship between the rate constant (k2) and pKa values was found to predict well the rate constant with an average absolute deviation (AAD) of 6.1%.

Kinetics of Carbon Dioxide (CO2) with DiethylenetriamineinNon-aqueous Solvents Using Stopped-flow Technique

In this work, the reaction kinetics of carbon dioxide (CO2) with diethylenetriamine (DETA)in methanol and ethanol systems were measured using the stopped flow technique over a temperature range of 293-313K in terms of pseudo first-order rate constant (k0). Concentration in the range of 10 to 50mol/m3 for diethylenetriamine were studied. The experimental data show that the pseudo first-order rate constants (k0) increase with the increase of both amine concentration and temperature. The zwitterion mechanism and the termolecular mechanism were used to representthe data for DETAinmethanol and ethanol systems with excllent ADDs of 3.5%, 2.4%, respectively. In comparison with EDA and AEEA in terms of k2, DETA exhibits a better reaction kinetics performance for capturingCO2. Those results will be useful in finding an efficient method for the removal of CO2 from industrial gases.

Reaction kinetics of carbon dioxide with aqueous solutions of l-Arginine, Glycine & Sarcosine using the stopped flow technique

The use of amino acids as potential solvents for carbon dioxide (CO2) capture has been considered by a number of researchers. However, very little is known about the kinetics and mechanism of amino acids-CO2 reactions. In this work, we investigate the reactions of three amino acids (l-Arginine, Glycine and Sarcosine) with CO2 in aqueous media using stopped-flow conductivity technique. The experiments were performed at temperatures between 293 and 313K and amino acids concentrations were in the range of 0.05–0.2 molar. The overall rate constants (kov) was found to increase with increased amino acid concentration and solution temperature. Both zwitterion and termolecular mechanisms were used to model and interpret the data. However, the Zwitterion mechanism was found to be the preferred one. From the stopped-flow results at pH around 6, we found that neutral l-Arginine, Glycine and Sarcosine react with CO2(aq) with k(M−1s−1)=2.81×1010exp(−4482.9T(K)), k(M−1s−1)=3.29×1013exp(−8143.7T(K)) and k(M−1s−1)=3.90×1013exp(−7991.0T(K)) respectively. The corresponding activation energies are 37.28kJmol−1, 67.71kJmol−1 And 66.44kJmol−1 respectively. A comparison between the kinetics of the three amino acids showed that Arginine exhibits highest reaction rate with CO2 followed by Sarcosine and then Glycine. The technique and results obtained from this work can be used as strong tools in the development of efficient new solvents for the removal of CO2 from flue and industrial gases.

Reaction kinetics of carbon dioxide and hydroxide in aqueous glycerol

The reaction kinetics of carbon dioxide and sodium hydroxide (nominally 0.1N and 0.3N) in aqueous glycerol were measured in a wetted wall column (WWC) at 20, 30, and 40°C. Glycerol was added at 0–89wt% to achieve a liquid viscosity (μL) of 0.89–65cP. Compared to pure aqueous alkaline solution, the absorption rate (kg′) initially increased by 30% and then decreased rapidly by 75% with increasing glycerol. Based on the measured kg′, a model was developed to calculate the overall reaction rate constant (kAlk), which resulted from the competing effects of CO2/NaOH (kOH-) and CO2/glyceroxide (kGlycerol-) reactions. The kGlycerol- was 6–7 times faster than kOH-. The non-monotonic trend of kg′ was the combined effect of kAlk increasing and diffusivity (DCO2) decreasing when glycerol increased. The effect of alkalinity depletion at the gas/liquid interface has been included in the kinetic model. The average depletion for 0.1N NaOH is 4% for water and 20% for 89wt% glycerol. Average depletion was less than 3% for 0.3N NaOH. The addition of 0.05N sodium carbonate has an insignificant effect on kg′.

Reaction Kinetics of Carbon Dioxide (CO2) with Diethylenetriamine and 1-Amino-2-propanol in Nonaqueous Solvents Using Stopped-Flow Technique

In this work, the reaction kinetics of carbon dioxide (CO2) with diethylenetriamine (DETA) and 1-amino-2-propanol (1-AP) in methanol and ethanol systems were measured using the stopped flow technique over a temperature range of 293–313 K in terms of pseudo-first-order rate constant (k0). Concentration in the range of 10 to 50 mol/m3 for diethylenetriamine, and 20 to 100 mol/m3 for 1-amino-2-propanol were studied. The experimental data show that the pseudo-first-order rate constants (k0) increase with the increase of both amine concentration and temperature. The zwitterion mechanism and the termolecular mechanism were used to represent the data for DETA in methanol and ethanol systems with excellent ADDs of 3.5% and 2.4%, respectively, and 1-AP in methanol and ethanol systems with excellent ADDs of 2.4% and 2.6%, respectively. In comparison with EDA and AEEA in terms of k2, DETA exhibits a better reaction kinetics performance for capturing CO2. Those results will be useful in finding an efficient method fo...

Reaction kinetics of carbon dioxide in aqueous blends of N-methyldiethanolamine and glycine using the stopped flow technique

Carbon dioxide managements and its association with global worming remains a major concern among governments and the scientific community, with novel, energy efficient and more affordable technologies topping the research agendas. Despite the importance of amino acids, their use as reaction promoters in combination with alkanolamines has been overlooked by researchers. Here, stopped-flow technique was used for the first time to measure the pseudo-first-order reaction kinetics of CO2 with various aqueous mixtures of N-methyldiethanolamine (MDEA) and glycine (Gly). The experiments were performed at a temperature range from 293 to 313 K and a total amine concentration up to 2 mol/l. The activation energy for CO2-MDEA reaction obtained from this work was found to be 49.24 kJ/mol, and the overall rate constants (kov) increased with increasing temperature and with increasing proportion of Glycine in the solution mixture. Using the zwitterion mechanism to interpret the CO2-MDEA-Gly reaction, we found that the glycine reacts with CO2 (aq) with k2 (M−1 s−1) = 2.40 × 107 exp(−3887.5/T(K)) with an activation energy of 22.95 kJ/mol.

Kinetics of Carbon Dioxide Binding by Promoted Organic Liquids

AbstractThe reaction kinetics of carbon dioxide and CO2‐binding organic liquids (CO2BOLs) promoted by piperazine (PZ) and its derivatives were investigated experimentally by stopped‐flow conductimetry. The study was carried out at 298 K and for a concentration range of 0–0.25 kmol m−3 of PZ, 1‐(2‐aminoethyl)piperazine (AEPZ) or 1‐(2‐hydroxyethyl)piperazine (NHEPZ) while the superbase (1,1,3,3‐tetramethylguanidine or 1,8‐diazabicyclo[5.4.0]undec‐7‐ene) concentrations were kept constant at 10.0 wt %. Based on pseudo‐first‐order reaction conditions, the intrinsic reaction rate data were analyzed according to a modified termolecular reaction mechanism. The results showed that the rate of reaction between CO2BOLs and CO2 could be significantly enhanced by blending with small amounts of PZ, NHEPZ or AEPZ as promoters.

Reaction Kinetics of Carbon Dioxide (CO2) Absorption in Sodium Salts of Taurine and Proline Using a Stopped-Flow Technique

The pseudo–first-order reaction rate constants (k0, s−1) for the reaction of carbon dioxide in aqueous solutions of sodium taurate (NaTau) and sodium prolinate (NaPr) were measured using a stopped-flow technique at a temperature range of 298–313 K. The solutions concentration varied from 5 to 50 mol m−3 and from 4 to 12 mol m−3 for NaTau and NaPr, respectively. Comparing the k0 values, aqueous NaPr was found to react very fast with CO2 as compared with the industrial standard aqueous monoethanolamine (MEA) and aqueous sodium taurate (NaTau) was found to react slower than aqueous MEA at the concentration range considered in this work. For the studied amino acid salts, the order of the reactions was found to be unity with respect to the amino acid salt concentration. Proposed reaction mechanisms such as termolecular and zwitterion reaction mechanisms for the reaction of CO2 with aqueous solutions were used for calculating the second-order reaction rate constants (k2, m3 mol−1 s−1). The formation of zwitterion during the reaction with CO2 was found to be the rate-determining step, and the deprotonation of zwitterion was instantaneous compared to the reverse reaction of zwitterion to form an amino acid salt. The contribution of water was established to be significant for the deprotonation of zwitterion. Comparing the pseudo–first-order reaction rate constants (k0, s−1) of various amino acid salts with CO2, NaPr was found to be the faster reacting amino acid salt. The activation energy for NaTau was found to be 48.1 kJ mol−1 and that of the NaPr was found to be 12 kJ mol−1. The Arrhenius expressions for the reaction between CO2 and the studied amino acid salts are

Kinetics of carbonation reaction of basic oxygen furnace slags in a rotating packed bed using the surface coverage model: Maximization of carbonation conversion

The reaction kinetics of carbon dioxide (CO2) capture by the accelerated carbonation of basic oxygen furnace slag (BOFS) in a rotating packed bed (RPB) was evaluated using the surface coverage model. Experimental data were utilized to determine the reaction rate constants and maximum carbonation conversion of BOFS based on the surface coverage model. The results indicate that the carbonation of BOFS in an RPB can be well-expressed by the surface coverage model, with R2 values from 0.98 to 0.99. In addition, the results of reaction kinetics could be validated by observation of SEM and XEDS before and after carbonation, which indicates that the reacted BOFS was surrounded by the CaCO3 product. On the other hand, the reaction kinetics of steelmaking slag in an RPB was compared with that in various types of reactors, i.e., autoclave and slurry reactors. The overall rate of carbonation in an RPB (i.e., 0.299min−1) was greater than that in both a slurry reactor (i.e., 0.227min−1) and an autoclave reactor (i.e., 0.033min−1). Furthermore, the maximum carbonation conversion of BOFS was initially determined by the results of the surface coverage model and then confirmed statistically by the response surface methodology (RSM). It was thus concluded that accelerated carbonation of BOFS in the RPB is a viable method due to its faster reaction kinetics under relatively milder reaction conditions. Accelerated carbonation of BOFS in the RPB is a promising process for CO2 capture due to its relatively higher carbonation conversion of BOFS within a shorter reaction time.

Reaction kinetics of carbon dioxide with 2-amino-2-hydroxymethyl-1,3-propanediol in aqueous solution obtained from the stopped flow method

Carbon dioxide (CO_2) capture has attracted great interest these days due to the role of CO_2 in global warming and its effects in industrial processes. Thus, higher energy efficient and affordable technologies are required for its removal so as to address these problems. In this work, the reaction kinetics of CO_2 with 2-amino-2-hyroxymethyl- 1,3-propanediol (AHPD), a sterically hindered amine (SHA), was studied by direct stopped flow method. The aim was to research CO_2 absorbent with better CO_2 absorption capacity and reaction kinetics than the commonly applied amine solvents. The study was carried out at 288, 298, and 303 K in a concentration range of 0.5-2.0 kmol/m^3 of AHPD. Based on the pseudo-first-order for the reaction of CO_2, it was found that the reaction can be modeled by a single termolecular reaction mechanism. The reaction rate between CO_2 and aqueous solution of AHPD was 9.99, 12.03, and 16.05 m^3/kmol.s at 288, 298, and 303 K, respectively, while its activation energy was 31.59 kJ/mol. The results obtained were compared with published reaction rate data of other amines. The present study shows that AHPD is a potential SHA as CO_2 absorbent if the reaction rate is enhanced by an additional amine.

Reaction Kinetics of Carbon Dioxide in Aqueous Diethanolamine Solutions Using the Stopped-Flow Technique

Reaction Kinetics of Carbon Dioxide in Aqueous Diethanolamine Solutions Using the Stopped-Flow Technique The pseudo-first-order rate constants (kOV) for the reactions between CO2 and diethanolamine have been studied using the stopped-flow technique in an aqueous solution at 293, 298, 303 and 313 K. The amine concentrations ranged from 167 to 500 mol·m-3. The overall reaction rate constant was found to increase with amine concentration and temperature. Both the zwitterion and termolecular mechanisms were applied to correlate the experimentally obtained rate constants. The values of SSE quality index showed a good agreement between the experimental data and the corresponding fit by the use of both mechanisms.

Reaction Kinetics of Carbon Dioxide with Phenyl Glycidyl Ether by TEA-CP-MS41 Catalyst

CP-MS41 was synthesized by hydrolysis of tetraorthosilicate, as a silicon source, with 3-chloropropyltriethoxysilane as an organosilane using cetyltrimethylammonium bromide as a template. TEA-CP-MS41 was synthesized by immobilization of triethylamine on the mesoporous MCM-41 and was dispersed in organic liquid as a mesoporous catalyst for the reaction between carbon dioxide and phenyl glycidyl ether (PGE). Carbon dioxide was absorbed into the PGE solution in a stirred batch tank with a planar gas-liquid interface within a range of 0-2.0 kmol/m3 of PGE and 333-363 K at 101.3 kPa. The measured values of absorption rate were analyzed to obtain the reaction kinetics using the mass transfer mechanism associated with the chemical reactions based on the film theory. The overall reaction of CO2 with phenyl glycidyl ether (PGE), which is assumed to consist of two steps: (i) A reversible reaction between PGE (B) and catalyst of TEA-CP-MS41 (QX) to form an intermediate complex (C1), and (ii) irreversible reaction between C1 and CO2 to form QX and five-membered cyclic carbonate (C), was used to obtain the reaction kinetics through the pseudo-first-order reaction model. Polar solvents such as N, N-dimethylacetamide, N-methyl-2-pyrrolidinone, and dimethyl sulfoxide affected the reaction rate constants.

Kinetics of carbon dioxide absorption into aqueous glucosamine solutions

AbstractChemical reaction kinetics of carbon dioxide with aqueous solutions of D (+) glucosamine hydrochloride (2‐amino‐2‐deoxy‐D‐glucose hydrochloride) has been studied using a stirred tank reactor with a planar interfacial area. The operational variables considered in this work have been the glucosamine concentration and the reaction temperature. Specific absorption rates have been obtained and different correlations have been employed to estimate physicochemical properties of carbon dioxide in glucosamine aqueous solutions. Results indicate that the absorption process occurs in a moderately fast reaction regime with a first‐order kinetic for amine and carbon dioxide. The reaction rate constant was calculated and correlated as a function of temperature. © 2007 American Institute of Chemical Engineers AIChE J, 2008

Reaction kinetics of carbon dioxide with glycidyl methacrylate using immobilized trioctylamine supported on poly(styrene-CO-vinylbenzyl chloride) as a catalyst

A soluble polymer-supprted catalyst containing pendant trioctylammonium chloride was synthesized by the radical copolymerization of p-chloromethylated styrene with styrene followed by the addition reaction of the resulting copolymer with trioctylamine. Absorption rate of carbon dioxide into glycidyl methacrylate (GMA) solutions containing the catalyst was measured using a semi-batch stirred tank with a plane gas-liquid interface at 101.3 kPa. The reaction kinetics of the reaction between carbon dioxide and GMA was evaluated using the absorption rate and the mass transfer mechanism of carbon dioxide. Solvents such as toluene, N-methyl-2-pyrrolidinone, and dimethyl sulfoxide influenced the reaction rate constants. Furthermore, this catalyst was compared to the monomeric tetraoctylammonium chloride under the same reaction conditions.

Reaction Kinetics of Carbon Dioxide with Diethanolamine in Polar Organic Solvents

The chemical absorption rate of carbon dioxide with diethanoamine was measured in such nonaqueous solvents as methanol, ethanol, n‐propanol, n‐butanol, ethylene glycol, propylene glycol, and propylene carbonate, and in water at 298 K and 101.3 kPa using a semibatch stirred tank with a plane gas‐liquid interface. The overall reaction rate constant obtained under the condition of fast reaction regime from the measured rate of absorption was used to get the elementary reaction rate constants in complicated reactions represented by reaction mechanism of carbamate formation and the order of overall reaction of CO2 with amine. Correlation between the elementary reaction rate constant and the solubility parameter of the solvent was presented.

Reaction kinetics of carbon dioxide with electrode carbon particles

Kinetic data for the reaction of carbon dioxide with electrode carbon particles 19 were used in a study of the reaction mechanism. A reactor with a single layer of carbon particles (50–60 mesh) was used throughout. Mass-specific reaction rates under fixed reaction conditions were found to vary with reaction time and were correlated with fractional carbon gasified. All measured rates were converted to values on fresh surface at zero reaction time. The reaction kinetics are well represented by the Langmuir-Hinshelwood type equation, the constants of which were converted to those of a reaction scheme in which oxygen exchange between gas phase and carbon surface is followed by carbon gasification. The equilibrium constants for the oxygen exchange reaction were calculated from the rate constants. Their values were found to agree with those from Grabke 28, but were much smaller than those from Ergun 9,10.

Reaction kinetics of carbon dioxide with amines in non-aqueous solvents

The rates of absorption of carbon dioxide into aqueous and non-aqueous solutions of monoisopropanolamine and cyclohexylamine were measured using a semibatch stirred tank with a plane gas-liquid interface at 303 K. The absorption rates under the fast reaction regime were analysed using chemical absorption theory. It was found that the order of reaction with respect to carbon dioxide was unity in every solution system, whereas the order of reaction with respect to mono-isopropanolamine was unity for an aqueous solution and had a value between 1.46 and 1.93 for the other alcoholic solution systems, as in the monoethanolamine case. The dependence of the logarithms of the reaction rate parameters included in the reaction scheme via a zwitterion on the solubility parameter of the solvent was found to be approximately linear, as in the ethanolamine case. The order of reaction with respect to cyclohexylamine was almost unity for aqueous and alcoholic solutions and 2 for toluene solution. The dependence of the logarithms of the second-order reaction rate constants in aqueous and alcoholic solutions on the reciprocal of the dielectric constant of the solvent was found to be approximately linear.