Exceptionally High CO2 Capturing Capacity of Porous Organic Polymers

Pre-combustion flue gas capture has been emerged as an efficient alternative to circumvent the costly procedures of materials regeneration utilized by the energy industry for CO2 capture and separation. Stability of the porous structure and repeated use at high pressure and high temperature are among the essential requirements for the efficient materials to be used for industrial level CO2 separation. Herein we report the CO2 adsorption-desorption performance of nanoporous covalent organic polymers (COPs), which can operate efficiently and repeatedly at elevated pressure of 200 bars and above. Since, pre-combustion capture also requires removal of hydrogen along with CO2; therefore, nanoporous COP was also tested for hydrogen removal at high pressure. COP material prepared with simple technique from building block monomers of cyanuric chloride and linked with 1,3-bis(4-piperidinyl)propane has enough surface area and pore volume which makes the material capable to store large quantity of syngas at high temperature and pressure. Results indicated that the newly synthesized COP material can adsorbed exceptionally large quantity of CO2 and very little hydrogen at 200 bars and 35°C. Additionally, the adsorption isotherm was exactly matched with the desorption isotherm, suggesting the material has excellent adsorption-desorption characteristics. Similarly, the material has shown very stable performance when used repeatedly and alternatively for CO2 and hydrogen after regeneration at 50°C. The capturing performance of material was also investigated for other gases like methane and nitrogen at various pressures and temperatures. Experimental results revealed that COP material has exceptional CO2 adsorption efficiency, very good selectivity, and strong stability and can be manufacture with simple techniques. Lastly, material is economically attractive when it is compared with the commercially available materials and has exceptional performance contrary to activated carbon, metal organic frame work and monoethanole amine.qscienc

Gas solubility and rheological behavior study of betaine and alanine based natural deep eutectic solvents (NADES)

Natural deep eutectic solvent (NADES) produced herein this work by mixing betaine and alanine with lactic acid and malic acid with 1:1 M mixing ratios. Thermophysical properties including water content, thermal stability, density and gas solubility of CO2 and N2 were experimented at different isotherms for wide pressures range up to 50 bars. Moreover, detailed rheological experiments were conducted on the studied materials to obtain viscosity and deduce the dynamic flow behavior. A pressure driven physisorption mechanism was observed for the studied systems. Betaine based NADES materials showed superior carbon dioxide and nitrogen solubility when they are mixed with lactic acid. On the other hand, the rheological experimental results show shear-thinning effect in which the η is decreasing with shear rate at all temperatures. Low viscosity profiles NADES assure the less mass transfer resistance for lactic acid based NADES systems and it also confirmed that the high CO2 and N2 solubility for lactic acid based NADES samples.NPRP grant # 6-330-2-140 from the Qatar National Research Fund (a member of Qatar Foundation) and by Ministerio de Economía y Competitividad (Spain, project CTQ2013-40476-R)

A detailed study of cholinium chloride and levulinic acid deep eutectic solvent system for CO2 capture via experimental and molecular simulation approaches

Choline chloride + levulinic acid deep eutectic solvent is studied as a suitable material for CO2 capturing purposes. The most relevant physicochemical properties of this solvent are reported together with the CO2 solubility as a function of temperature. The corrosivity of this solvent is studied showing better performance than amine-based solvents. A theoretical study using both density functional theory and molecular dynamics approaches is carried out to analyze the properties of this fluid from the nanoscopic viewpoint, and their relationship with the macroscopic behavior of the system and its ability for CO2 capturing. The behavior of the liquid–gas interface is also studied and its role on the CO2 absorption mechanism is analyzed. The reported combined experimental and theoretical approach leads to a complete picture of the behavior of this new sorbent with regard to CO2, which together with its low cost, and the suitable environmental and toxicological properties of this solvent, lead to a promising candidate for CO2 capturing technological applicationsMinisterio de Economı´a y Competitividad (Spain, project CTQ2013-40476-R) and Junta de Castilla y Leo´n (Spain, project BU324U1

Investigation of Ester- and Amide-Linker-Based Porous Organic Polymers for Carbon Dioxide Capture and Separation at Wide Temperatures and Pressures

Organic compounds, such as covalent organic framework, metal–organic frameworks, and covalent organic polymers have been under investigation to replace the well-known amine-based solvent sorption technology of CO2 and introduce the most efficient and economical material for CO2 capture and storage. Various organic polymers having different function groups have been under investigation both for low and high pressure CO2 capture. However, search for a promising material to overcome the issues of lower selectivity, less capturing capacity, lower mass transfer coefficient and instability in materials performance at high pressure and various temperatures is still ongoing process. Herein, we report synthesis of six covalent organic polymers (COPs) and their CO2, N2, and CH4 adsorption performances at low and high pressures up to 200 bar. All the presented COPs materials were characterized by using elemental analysis method, Fourier transform infrared spectroscopy (FTIR) and solid state nuclear magnetic resonance (NMR) spectroscopy techniques. Physical properties of the materials such as surface areas, pore volume and pore size were determined through BET analysis at 77 K. All the materials were tested for CO2, CH4, and N2 adsorption using state of the art equipment, magnetic suspension balance (MSB). Results indicated that, amide based material i.e. COP-33 has the largest pore volume of 0.2 cm2/g which can capture up to the maximum of 1.44 mmol/g CO2 at room temperature and at pressure of 10 bar. However, at higher pressure of 200 bar and 308 K ester-based compound, that is, COP-35 adsorb as large as 144 mmol/g, which is the largest gas capturing capacity of any COPs material obtained so far. Importantly, single gas measurement based selectivity of COP-33 was comparatively better than all other COPs materials at all condition. Nevertheless, overall performance of COP-35 rate of adsorption and heat of adsorption has indicated that this material can be considered for further exploration as efficient and cheaply available solid sorbent material for CO2 capture and separation.Qatar National Research Fund, National Priorities Research Program grant (NPRP 5-499-1-088)

Photocatalytic oxidation of air toxics via visible light irradiation and nano-photocatalysts

This thesis explores synthesis of various types of metal oxide nanoparticles through a wet-chemical synthesis route. The materials were used for photocatalytic oxidation of gaseous toluene irradiated with UV, artificial solar light, and pure visible light. Tantalum based compounds like BiTaO4: La, BiNbO4: Ga and Ta2O5 have shown better performance than a commercial TiO2 under UV and solar light. Ta2O5 and nitrogen doped Ta2O5 have shown excellent performance for toluene oxidation with solar and visible light

Nanoporous Polymeric Materials For Co2 Capture And Separation

Control of carbon dioxide emissions without significant penalties requires effective CO2 scrubbing from point sources, such as fossil fuel burning power plants, cement factories and steel making. Capturing process is the most costly; hence the research is directed to finding solutions to it. Efficient CO2 scrubbing without a significant energy penalty remains an outstanding challenge for fossil fuel-burning industry where aqueous amine solutions are still widely used. Porous materials have long been evaluated for next generation CO2 adsorbents. Porous polymers, robust and inexpensive, show promise as feasible materials for the capture of CO2 from warm exhaust fumes. Nanoporous polymeric materials show considerable CO2 uptakes and are likely to replace monoethanol amine (MEA) solutions for industrial CO2 capture. We report recently developed nanoporous covalent organic polymers (COPs), which show significant capacities and selectivities for CO2. To name a few, COP-1 shows 5.6 g/g CO2 uptake at 200 bar and 45 °C, COP-2 shows a CO2/H2 selectivity of over 10:1 and COP-33 1.8 g/g at CO2 uptake at 200 bar 50 °C with a CO2/H2 selectivity of 3:1. These results point to an ideal nanoporous structure to be made from a highly porous, inexpensive, physisorptive solid, which is chemically modified with amine functionalities.qscienc

On the evaluation of flue gases capturing capacity of porous organic materials

Integrated Gasification Combined Cycle (IGCC) has been emerged as an efficient alternative to post and oxy-combustion systems for power generation with controllable CO2 capture and separation. However, this system operates and requires separation of gases at high pressure prior to combustion which subsequently demands highly stable material for CO2 capture and separation. Pre-combustion flue gas capture has been instigated as an alternative to circumvent the costly procedures of materials regeneration utilized by the energy industry for CO2 capture and separation[1]. Stability of the porous structure and repeated use at high pressure and high temperature are among the essential requirements for the efficient materials to be used for industrial level CO2 separation [2, 3]. Herein we report the CO2 adsorption-desorption performance of nanoporous covalent organic polymers (COPs), which can operate efficiently and repeatedly at elevated pressure of 200 bars and above. Since, pre-combustion capture also requires removal of hydrogen along with CO2; therefore, nanoporous COP was also tested for hydrogen removal at high pressure. COP material prepared with simple technique from building block monomers of cyanuric chloride and linked with 1, 3-bis(4-piperidinyl)propane has enough surface area and pore volume which makes the material capable to store large quantity of syngas at high temperature and pressure. Results indicated that the newly synthesized COP material can adsorbed exceptionally large quantity of CO2 and very little hydrogen at 200 bars and 35 °C. Additionally, the adsorption isotherm was exactly matched with the desorption isotherm, suggesting the material has excellent adsorption-desorption characteristics. Similarly, the material has shown very stable performance when used repeatedly and alternatively for CO2 and hydrogen after regeneration at 50 °C. The capturing performance of material was also investigated for other gases like methane and nitrogen at various pressures and temperatures. Experimental results revealed that COP material has exceptional CO2 adsorption efficiency, very good selectivity, and strong stability and can be manufacture with simple techniques. Upon comparing with other materials like hyper cross-linked polymers, amine modified SBA-15[4], poly-benzimidazole activated carbon, and organic networks[5], it was found that covalent organic polymers presented here has exceptionally high CO2 uptake capacity, release very low heat of adsorption and possess very good mass transfer coefficient[6]. Lastly, material is economically viable when it is compared with the commercially available materials and has exceptional performance contrary to monoethanole amine.Scopu

Comparative investigation of photocatalytic degradation of toluene on Nitrogen doped Ta2O5 and Nb2O5 nanoparticles

Nb2O5 and Ta2O5 nanoparticles were prepared at a moderate sintering temperature of 700 °C using a solution method. Nitrogen doped Nb2O5 and Ta2O5 were obtained by ammonia gas treatment at 700 °C. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and UV-vis diffuse reflectance spectroscopy. All the materials were used for photocatalytic decomposition of gaseous toluene irradiated with artificial solar light and pure visible light. Most of the materials were multiple crystallites with orthorhombic and monoclinic structures. Tantalum based compounds, undoped (Ta2O5 (lab)) and nitrogen doped (Ta2O5:N (lab)), have shown much better performance than niobium based materials. Ta2O5:N (lab) decomposed gaseous toluene with a rate similar to those of Ta2O5 (lab) and Ta2O5:N (com) in the initial 60 min but at a higher rate at extended time under artificial sunlight. Ta2O5:N (lab) decomposed about 70% toluene with artificial sunlight and 30% with pure visible light (lambda = 400 nm). The material also exhibited a very stable performance with artificial sunlight and pure visible light

Comparative study on low and high pressure CO2 adsorption capacity of organic materials

Application of solid sorbents for CO2 capture and separation has been under consideration since last decades owing to the promising feature of repeatable use, low cost of regeneration and thermo physical stability. However, the capturing capacity, selectivity and the overall performance of adsorbents at different temperatures and pressures still require further investigation to make these materials capable of replacing the mono-ethanol system. Here in we report synthesis, characterization and application of covalent organic polymers. Capturing capacity of COPs at low temperature and pressure has been experimented for two COPs materials (namely COP-9, COP-10) for CO2 and N2 adsorption. Materials were also characterized with BET and TGA. Copyright 2017 American Institute of Chemical Engineers. All rights reserved.This paper was made possible by the support of Qatar National Research Fund, National Priorities Research Program grant (NPRP# 5-499-1-088) and (NPRP# 6-330-2-140). The statements made herein are solely the responsibility of the authors.Scopu

Insights into choline chloride-phenylacetic acid deep eutectic solvent for CO2 absorption

The properties of choline chloride plus phenylacetic acid deep eutectic solvents in neat liquid state and upon absorption of CO2 are analyzed using a theoretical approach combining quantum chemistry using Density Functional Theory and classic molecular dynamics methods. This study investigates the physicochemical properties, structuring, dynamics and interfacial behavior of the selected deep eutectic solvent from the nano-size point of view to infer its viability for effective CO2 capture. DFT results provided information on the mechanism of short-range interactions between CO2 and the studied DES, showing a better performance than previously studied DES. The mechanism of CO2 capture is analyzed considering model flue gas, showing a two-stage process with water, CO2 and N2 molecules developing adsorbed layers at the interface but in different regions. Water adsorbed layers would delay the migration of CO2 molecules toward bulk liquid regions, which should be considered for developing large-scale applications.Scopu