Download or read book Modeling of Carbon Dioxide Absorption Using Aqueous Monoethanolamine Piperazine and Promoted Potassium Carbonate written by Jorge Mario Plaza and published by . This book was released on 2012 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rigorous CO2 absorption models were developed for aqueous 4.5 m K+/4.5 m PZ, monoethanolamine (7m - 9m), and piperazine (8m) in Aspen Plus® RateSepTM. The 4.5 m K+/4.5 m PZ model uses the Hilliard thermodynamic representation and kinetics based on work by Chen. The MEA (Phoenix) and PZ (5deMayo) models incorporate new data for partial pressure of CO2 vs. loading and kinetics from wetted wall column data. They use reduced reaction sets based on the more relevant species present at the expected operating loading. Kinetics were regressed to match reported carbon dioxide flux data using a wetted wall column (WWC). Density and viscosity were satisfactorily regressed to match newly obtained experimental data. The activity coefficient of CO2 was also regressed to include newly obtained CO2 solvent solubility data. The models were reconciled and validated using pilot plant data obtained from five campaigns conducted at the Pickle Research Center. Performance was matched within 10% of NTU for most runs. Temperature profiles are adequately represented in all campaigns. The calculated temperature profiles showed the effect of the L/G on the location and magnitude of the temperature bulge. As the L/G is increased the temperature bulge moves from near the top of the column towards the bottom and its magnitude decreases. Performance improvement due to intercooling was validated across the campaigns that evaluated this process option. Absorber intercooling was studied using various solvent rates (Lmin, 1.1 Lmin and 1.2 Lmin). It is most effective at the critical L/G where the temperature bulge without intercooling is in the middle of the column. In this case it will allow for higher absorption by reducing the magnitude of the bulge temperature. The volume of packing to get 90% removal with L/Lmin =1.1 at the critical L/G is reduced by 30% for 8m PZ. For MEA and a solvent flow rate of 1.1 Lmin packing volume is increased with intercooling at constant L/G. This increase is compensated by higher solvent loadings that suggest lower stripping energy requirements. The critical L/G is 4.3 for 8m PZ, 6.9 for 9m MEA and 4.1 for K+/PZ.

Download or read book Carbon Dioxide Absorption Into Piperazine Promoted Potassium Carbonate Using Structured Packing written by Eric Chen and published by . This book was released on 2007 with total page 1010 pages. Available in PDF, EPUB and Kindle. Book excerpt: A large-scale pilot plant (0.43 m ID) was extensively modified and converted into an absorber/stripper system to demonstrate CO2 capture technology using aqueous piperazine promoted potassium carbonate for coalfired power plants. Four pilot plant campaigns were completed. Three campaigns were conducted using 5 m K/2.5 m PZ and 6.4 m K/1.6 m PZ. Flexipac 1Y and Flexipac AQ Style 20 structured packing were used in the absorber. The stripper was tested with 14 sieve trays, IMTP #40 random packing, and Flexipac AQ Style 20 packing. Monoethanolamine (7 m) was tested in the third campaign to establish a base case. An approximate rate analysis showed that 5 m K+/2.5 m PZ is two times faster than 7 m MEA and three times faster than 6.4 m K+/1.6 m PZ. The location of the temperature bulge moves from the top of the column to bottom as the liquid to gas flow rate ratio is increased. Foaming occurred in the absorber in the first two campaigns and occurred in the stripper in the fourth campaign. Data from the pilot plant was used to develop a K+/PZ absorber model in Aspen Plus® RateSep[trademark]. The Hilliard (2005) Aspen Plus® VLE model and the kinetics developed by Cullinane (2005) were incorporated in the model. Data-Fit was simultaneously used to reconcile pilot plant data and perform a regression of the interfacial area and heat loss parameters for the RateSep[trademark] absorber model. The lean loading for the pilot plant data was shifted down by 10% to account for a discrepancy with the Cullinane vapor-liquid equilibrium data. The Data-Fit results showed that the average interfacial area for Flexipac 1Y was 80% of the value measure by the air-water column. The average interfacial area for Flexipac AQ Style 20 for 5 m K+/2.5 m PZ was 56% of the air-water measurement. The CO2 heat of absorption may not have been adequately predicted by the RateSep[trademark] absorber model because the regressed values of heat loss were consistent with forced convection.

Download or read book A Predictive Thermodynamic Model for an Aqueous Blend of Potassium Carbonate Piperazine and Monoethanolamine for Carbon Dioxide Capture from Flue Gas written by Marcus Douglas Hilliard and published by . This book was released on 2008 with total page 2008 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Electrolyte Nonrandom Two-Liquid Activity Coefficient model in Aspen PlusTM 2006.5 was used to develop a rigorous and consistent thermodynamic representation for the base sub-component systems associated with aqueous combinations of K2CO3, KHCO3, MEA, and piperazine (PZ) in a mixed-solvent electrolyte system for the application of CO2 absorption/stripping from coal fired power plants. We developed a new vapor-liquid equilibrium apparatus to measure CO2, amine, and H2O vapor pressures at 40 and 60 oC. We found that the volatility of MEA and PZ can be approximated at 50 and 20 ppmv at 40°C for any solvent composition studied in this work, over the CO2 partial pressure range from 0.01 to 0.1 kPa. Very few solvent compositions exhibited a greater differential capacity than 7 m MEA at 60°C; specifically 11 m MEA, 3.5 m MEA + 3.6 m PZ, 7 m MEA + 2 m PZ, 7 m MEA + 3.6 m PZ, and 5 m K+ + 7 m MEA + 3.6 m PZ. Piperazine exhibited a possible maximum differential capacity of 2.21 mole CO2/kg-H2O at a concentration of 7.3 m. At the Norwegian University of Science and Technology, Inna Kim determined the differential enthalpy of CO2 absorption for aqueous combinations of K2CO3, KHCO3, MEA, PZ, and CO2, based on a consistent experimental method developed for MEA, from 40 to 120°C for use in this work. In addition, we developed a consistent method to measure the specific heat capacity for a number of similar solvent combinations. We found that the enthalpy of CO2 absorption increased with temperature because the apparent partial heat capacity of CO2 may be considered small. Finally, by using a differential scanning calorimeter, we determined the dissolution temperature for aqueous mixtures of unloaded piperazine, which inferred an effective operating range for solutions of concentrated piperazine, greater than 5 m PZ, over a loading range between 0.25 to 0.45 mole CO2/2·mol PZ. Through unit cell x-ray diffraction, we were able to identify and characterize the presence of three solid phases (PZ·6H2O, KHCO3, and KvPZ(COO)2) in aqueous mixture combinations of K2CO3, KHCO3, PZ, and CO2.

Download or read book Carbon Dioxide Absorption with Aqueous Potassium Carbonate Promoted by Piperazine written by J. Tim Cullinane and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental and Theoretical Study of Carbon Dioxide Absorption Into Potassium Carbonate Solution Promoted with Enzyme written by Arezoo Khodayari and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: According to the Intergovernmental Panel on Climate Change (IPCC), carbon dioxide (CO2) concentration in the atmosphere has increased from its pre-industrial value of 280 parts per million by volume (ppmv) to 384 ppmv. IPCC predicts that CO2 concentration in the atmosphere will rise to 550 ppmv by the year 2100, if anthropogenic emissions continue to increase. The average temperature at the Earth's surface could increase 1.8-4.0K above the 1990 levels by the end of this century. Such warming is anticipated to cause sea level rise, increased intensity and frequency of extreme weather events, ice shelf disruption, and changes in rainfall patterns. As a result, reducing CO2 emissions from anthropogenic sources is a high priority. Combustion of fossil fuels for power generation is the major contributors of CO2 emission into the environment. Currently, CO2 chemical absorption using monoethanolamine (MEA) as a solvent is the best available option for CO2 capture from flue gas streams. The issue with this technology is the high capture cost which ranges from $50/metric ton to $70/metric ton CO2 avoided. Energy consumption by the process contributes to 60% of the cost. Thus, use of solvents with lower heats of absorption is preferable. A novel process called Integrated Vacuum Carbonate Absorption Process (IVCAP), which employs potassium carbonate (PC) as a solvent, has been proposed. Since chemical affinity of CO2 to K2CO3 is weak compared to MEA, the regeneration of CO2-rich solution can be operated under vacuum at a lower temperature. Hence, a low quality steam from the power plant steam cycle can be used as the heat source for the regeneration. IVCAP process is expected to have 25-30% lower energy requirements as compared to an MEA-based process. However, compared with the MEA solution, PC solutions with low heats of absorption generally exhibit much slower CO2 absorption rates. Hence, a biological catalyst, carbonic anhydrase (CA) was investigated to promote the rate of CO2 absorption into select PC solutions. Experiments were performed in a stirred-tank reactor to evaluate the activity of the CA enzyme under IVCAP conditions. Results revealed that addition of up to 300 mg/l CA enzyme to the PC solutions at 25oC increases the absorption rate by a factor of 6-20 when compared with the same solution without the CA. It was also observed that, the CO2 absorption rates into the aqueous PC solutions with different initial conversion levels of PC to potassium bicarbonate are similar, with differences no larger than 20%, when the concentration of CA enzyme is 300 mg/l. It was also observed that, at the 300 mg/l CA concentration, increasing the temperature from 25oC to 50oC reduces the rate of CO2 absorption, by up to 20%. A mathematical model based on Higbie's penetration theory was developed to simulate the absorption of CO2 into the PC solutions. A comparison of modeled to experimental absorption rates of CO2 provided agreement within 30%. The modeling results revealed that at CA concentrations > 3,000 mg/l, the absorption rate of CO2 is independent of CA concentration. Compared to the enzyme concentration (300 mg/l) used in this study, a further increase of enzyme concentration to a level not larger than 3,000 mg/l could further increase the absorption rate of CO2. Based on the experimental and modeling results obtained in this research, it is recommended that the CO2 absorption rate into PC-CA be further enhanced by improving other parameters such as the activity of CA enzyme and design optimization of the absorption column including the type of packing material. Further work is required to investigate the stability of the CA enzyme at longer test duration and use of immobilized CA enzyme. Effectiveness of the regeneration cycle also needs to be investigated. Further work should also include the test of an integrated absorption/ regeneration system for CO2 capture at a real flue gas condition. 0́3

Download or read book CO2 Capture by Absorption with Potassium Carbonate written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this work is to improve the process for CO2 capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K2CO3 promoted by piperazine. The final campaign of the pilot plant was completed in February 2006 with 5m K/2.5m PZ and 6.4m K/1.6m PZ using Flexipac AQ Style 20. The new cross-exchanger reduced the approach temperature to less than 9 C. Stripper modeling has demonstrated that a configuration with a ''Flashing Feed'' requires 6% less work that a simple stripper. The oxidative degradation of piperazine proceeds more slowly than that of monoethanolamine and produces ethylenediamine and other products. Uninhibited 5 m KHCO3/2.5 m PZ corrodes 5 to 6 times faster that 30% MEA with 0.2 mol CO2/mol MEA.

Download or read book Gas liquid Reactions written by P. V. Danckwerts and published by . This book was released on 1970 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Process Systems and Materials for CO2 Capture written by Athanasios I. Papadopoulos and published by John Wiley & Sons. This book was released on 2017-03-07 with total page 925 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive volume brings together an extensive collection of systematic computer-aided tools and methods developed in recent years for CO2 capture applications, and presents a structured and organized account of works from internationally acknowledged scientists and engineers, through: Modeling of materials and processes based on chemical and physical principles Design of materials and processes based on systematic optimization methods Utilization of advanced control and integration methods in process and plant-wide operations The tools and methods described are illustrated through case studies on materials such as solvents, adsorbents, and membranes, and on processes such as absorption / desorption, pressure and vacuum swing adsorption, membranes, oxycombustion, solid looping, etc. Process Systems and Materials for CO2 Capture: Modelling, Design, Control and Integration should become the essential introductory resource for researchers and industrial practitioners in the field of CO2 capture technology who wish to explore developments in computer-aided tools and methods. In addition, it aims to introduce CO2 capture technologies to process systems engineers working in the development of general computational tools and methods by highlighting opportunities for new developments to address the needs and challenges in CO2 capture technologies.

Download or read book Energy Efficient Solvents for CO2 Capture by Gas Liquid Absorption written by Wojciech M. Budzianowski and published by Springer. This book was released on 2016-12-01 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews and characterises promising single-compound solvents, solvent blends and advanced solvent systems suitable for CO2 capture applications using gas-liquid absorption. Focusing on energy efficient solvents with minimal adverse environmental impact, the contributions included analyse the major technological advantages, as well as research and development challenges of promising solvents and solvent systems in various sustainable CO2 capture applications. It provides a valuable source of information for undergraduate and postgraduate students, as well as for chemical engineers and energy specialists.

Download or read book Recent Advances in Carbon Capture and Storage written by Yongseung Yun and published by BoD – Books on Demand. This book was released on 2017-03-08 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon capture and storage (CCS) has been considered as a practical way in sequestering the huge anthropogenic CO2 amount with a reasonable cost until a more pragmatic solution appears. The CCS can work as a bridge before fulfilling the no-CO2 era of the future by applying to large-scale CO2 emitting facilities. But CCS appears to lose some passion by the lack of progress in technical developments and in commercial success stories other than EOR. This is the time to go back to basics, starting from finding a solution in small steps. The CCS technology desperately needs far newer ideas and breakthroughs that can overcome earlier attempts through improving, modifying, and switching the known principles. This book tries to give some insight into developing an urgently needed technical breakthrough through the recent advances in CCS research, in addition to the available small steps like soil carbon sequestration. This book provides the fundamental and practical information for researchers and graduate students who want to review the current technical status and to bring in new ideas to the conventional CCS technologies.

Download or read book Carbon dioxide absorption in aqueous mixtures of potassium carbonate and piperazine written by John Timothy Cullinane and published by . This book was released on 2002 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon Dioxide Absorption Desorption and Diffusion in Aqueous Piperazine and Monoethanolamine written by Ross Edward Dugas and published by . This book was released on 2009 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work includes wetted wall column experiments that measure the CO2 equilibrium partial pressure and liquid film mass transfer coefficient (kg') in 7, 9, 11, and 13 m MEA and 2, 5, 8, and 12 m PZ solutions. A 7 m MEA/2 m PZ blend was also examined. Absorption and desorption experiments were performed at 40, 60, 80, and 100°C over a range of CO2 loading. Diaphragm diffusion cell experiments were performed with CO2 loaded MEA and PZ solutions to characterize diffusion behavior. All experimental results have been compared to available literature data and match well. MEA and PZ spreadsheet models were created to explain observed rate behavior using the wetted wall column rate data and available literature data. The resulting liquid film mass transfer coefficient expressions use termolecular (base catalysis) kinetics and activity-based rate expressions. The kg' expressions accurately represent rate behavior over the very wide range of experimental conditions. The models fully explain rate effects with changes in amine concentration, temperature, and CO2 loading. These models allow for rate behavior to be predicted at any set of conditions as long as the parameters in the kg' expressions can be accurately estimated. An Aspen Plus® RateSep[trademark] model for MEA was created to model CO2 flux in the wetted wall column. The model accurately calculated CO2 flux over the wide range of experimental conditions but included a systematic error with MEA concentration. The systematic error resulted from an inability to represent the activity coefficient of MEA properly. Due to this limitation, the RateSep[trademark] model will be most accurate when finetuned to one specific amine concentration. This Aspen Plus® RateSep[trademark] model allows for scale up to industrial conditions to examine absorber or stripper performance.

Download or read book The Principles of Chemical Equilibrium written by Kenneth George Denbigh and published by Cambridge University Press. This book was released on 1981-03-26 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sample Text

Download or read book Process Intensification written by Fernando Israel Gómez-Castro and published by Walter de Gruyter GmbH & Co KG. This book was released on 2019-10-21 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intensified processes have found widespread application in the chemical and petrochemical industries. The use of intensified systems allows for a reduction of operating costs and supports the “greening” of chemical processes. However, the design of intensified equipment requires special methodologies. This book describes the fundamentals and applications of these design methods, making it a valuable resource for use in both industry and academia.

Download or read book Process Systems and Materials for CO2 Capture written by Athanasios I. Papadopoulos and published by John Wiley & Sons. This book was released on 2017-05-01 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive volume brings together an extensive collection of systematic computer-aided tools and methods developed in recent years for CO2 capture applications, and presents a structured and organized account of works from internationally acknowledged scientists and engineers, through: Modeling of materials and processes based on chemical and physical principles Design of materials and processes based on systematic optimization methods Utilization of advanced control and integration methods in process and plant-wide operations The tools and methods described are illustrated through case studies on materials such as solvents, adsorbents, and membranes, and on processes such as absorption / desorption, pressure and vacuum swing adsorption, membranes, oxycombustion, solid looping, etc. Process Systems and Materials for CO2 Capture: Modelling, Design, Control and Integration should become the essential introductory resource for researchers and industrial practitioners in the field of CO2 capture technology who wish to explore developments in computer-aided tools and methods. In addition, it aims to introduce CO2 capture technologies to process systems engineers working in the development of general computational tools and methods by highlighting opportunities for new developments to address the needs and challenges in CO2 capture technologies.

Download or read book Thermodynamics and Kinetics of Aqueous Piperazine with Potassium Carbonate for Carbon Dioxide Absorption written by and published by . This book was released on 2005 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work proposes an innovative blend of potassium carbonate (K2CO3) and piperazine (PZ) as a solvent for CO2 removal from combustion flue gas in an absorber/stripper. The equilibrium partial pressure and the rate of absorption of CO2 were measured in a wetted-wall column in 0.0 to 6.2 m K and 0.6 to 3.6 m PZ at 25 to 110 C. The equilibrium speciation of the solution was determined by 1H NMR under similar conditions. A rigorous thermodynamic model, based on electrolyte non-random two-liquid (ENRTL) theory, was developed to represent equilibrium behavior. A rate model was developed to describe the absorption rate by integration of eddy diffusivity theory with complex kinetics. Both models were used to explain behavior in terms of equilibrium constants, activity coefficients, and rate constants. The addition of potassium to the amine increases the concentration of CO32−/HCO3− in solution. The buffer reduces protonation of the amine, but increases the amount of carbamate species, yielding a maximum reactive species concentration at a K:PZ ratio of 2:1. The carbamate stability of piperazine carbamate and dicarbamate resembles that of primary amines and has approximately equal values for the heats of reaction, [Delta]H{sub rxn} (18.3 and 16.5 kJ/mol). The heat of CO2 absorption is lowered by K+ from -75 to -40 kJ/mol. The capacity increases as total solute concentration increases, comparing favorably with 5 M monoethanolamine (MEA). The rate approaches second-order behavior with PZ and is highly dependent on other strong bases. In 1 M PZ, the overall rate constant is 102,000 s−1, 20 times higher than in MEA. The activation energy is 35 kJ/kmol. In K+/PZ, the most significant reactions are PZ and piperazine carbamate with CO2 catalyzed by carbonate. Neutral salts in aqueous PZ increase the apparent rate constant, by a factor of 8 at 3 M ionic strength. The absorption rate in 5 m K+/2.5 m PZ is 3 times faster than 30 wt% MEA. A pseudo-first order approximation represents the absorption rate under limited conditions. At high loadings, the reaction approaches instantaneous behavior. Under industrial conditions, gas film resistance may account for>80% of the total mass transfer resistance at low loadings.

Download or read book Hollow Fiber Membrane Contactors written by Anil K. Pabby and published by CRC Press. This book was released on 2020-11-23 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book on hollow fiber contractors presents an up-to-date compilation of the latest developments and milestones in this membrane technology. Hollow Fiber Membrane Contactors: Module Fabrication, Design and Operation, and Potential Applications provides a comprehensive discussion of hollow fiber membrane applications (including a few case studies) in biotechnology, chemical, food, and nuclear engineering. The chapters in this book have been classified using the following, based on different ways of contacting fluids with each other: Gas-liquid contacting; Liquid-liquid contacting; Supported liquid membrane; Supported gas membrane; Fluid-fluid contacting. Other features include: Discusses using non-dispersive solvent extraction, hollow fiber strip dispersion, hollow fiber supported liquid membranes and role of process intensification in integrated use of these processes Provides technical and economic perspectives with several case studies related to specific scenarios Demonstrates module fabrication, design, operation and maintenance of hollow fiber contactors for different applications and performance Presents discussion on newer concepts like membrane emulsification, membrane nanoprecipitation, membrane crystallization and membrane condenser Special focus on emerging areas such as the use of hollow fiber contactor in back end of nuclear fuel cycle, membrane distillation, dehumidification of air and gas absorption and stripping Discusses theoretical analysis including computational modeling of different hollow fiber membrane processes, and presents emphasis on newly developed area of hollow fiber membrane based analytical techniques Presents discussion on upcoming area dealing with hollow fiber contactors-based technology in fermentation and enzymatic transformation and in chiral separations This book is equally suited for newcomers to the field, as well as for engineers and scientists that have basic knowledge in this field but are interested in obtaining more information about specific future applications.