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)

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

High performance CO2 filtration and sequestration by using bromomethyl benzene linked microporous networks

Porous solid sorbents have been investigated for the last few decades to replace the costly amine solution and explore the most efficient and economical material for CO2 capture and storage. Covalent organic polymers (COPs) have been recently introduced as promising materials to overcome several issues associated with the solid sorbents such as thermal stability and low gas capturing capacity. Herein we report the synthesis of four COPs and their CO2, N2 and CH4 uptakes. All the presented COP materials were characterized by using an elemental analysis method, Fourier transform infrared spectroscopy (FTIR) and solid state nuclear magnetic resonance (NMR) spectroscopy techniques. The physical properties of the materials such as surface area, pore volume and pore size were determined by BET analysis at 77 K. All the materials were tested for CO2, CH4 and N2 adsorption through a volumetric method using magnetic sorption apparatus (MSA). Among the presented materials, COP-118 has the highest surface area of 473 m2 g-1 among the other four materials and has shown excellent performance by capturing 2.72 mmol g-1 of CO2, 1.002 mmol g-1 of CH4 and only 0.56 mmol g-1 of N2 at 298 K and 10 bars. However the selectivity of another material, COP-117-A, was better than that of COP-118. Nevertheless, the overall performance of the latter has indicated that this material can be considered for further exploration as an efficient and cheaply available solid sorbent compound for CO2 capture and separation. 2016 The Royal Society of Chemistry.Scopu

Carbon Dioxide Solubility in Phosphonium-, Ammonium-, Sulfonyl-, and Pyrrolidinium-Based Ionic Liquids and their Mixtures at Moderate Pressures up to 10 bar

Carbon dioxide solubility in four ionic liquids (ILs) of different families with different cationic-anionic groups (tributylmethylphosphonium formate, butyltrimethylammonium bis(trifluoromethyl sulfonyl) imide, 1-methyl-1-propylpyrrolidinium dicyanamide, and 1-ethyl-3-methylimidazolium acetate) at temperature of 298 K and a pressure range from vacuum to 10 bar were studied in this work using state of the art gravimetric sorption experiments. This work provides insight information regarding CO2 solubility for IL-IL mixing effect pressures up to 10 bar and at 298 K. Density values were used to calculate molar volume of ionic liquids for further discussions on CO2 solubility-molar volume relationship. Noticeably higher CO2 solubility with IL-IL hybridized systems of different family is opening a new window for research on a molecular level by simulations and intellectually designed ILs. Chemisorption behavior has been observed for the ILs that contain acetate-based anions in the structure and relevant discussion is included in this work. (Graph Presented).This paper was made possible by the support of Qatar National Research Fund, Undergraduate Research Experience Program (UREP 15-131-2-044) and National Priorities Research Program Grant (NPRP 6-330-2-140). The statements made herein are solely the responsibility of the authors. We also acknowledge Ministerio de Econom?a y Competitividad (Spain, project CTQ2013-40476-R) and Junta de Castilla y Le?n (Spain, project BU324U14).Scopu

Double Salt Ionic Liquids Based on Ammonium Cations and Their Application for CO₂ Capture

Simple ionic liquids (containing one type of cation with one type of anion) and complex mixed ionic liquids (containing several types of anions and cations, double salts) based on ammonium cations were studied in this work using a combined computational and experimental approach. Theoretical studies were carried out using classical molecular dynamics simulations. The properties and structure of these fluids and their changes upon CO₂ absorption were analyzed. The fluids’ structural, energetic, and dynamic properties were considered as a function of the type of ions composing the ionic liquids together with their changes when CO₂ is present as a function of CO₂ concentration. Likewise, experimental measurements analyze carbon capturing abilities for the studied mixed ionic liquids as a function of pressure and temperature. The reported results show that mixing two neat ammonium-based ionic liquids does not change remarkably the properties of the involved neat ionic liquids, and also the affinities for CO₂ are also similar in the mixed ionic liquids. Therefore, vastly different ions should be considered when mixed ionic liquids are designed for stimulating CO₂ physisorption by increasing the available volume and tuning affinity toward CO₂. This work provides a nanoscopic and macroscopic characterization of complex ionic liquids and their ability for carbon capturing for the first time

High-Pressure Methane, Carbon Dioxide, and Nitrogen Adsorption on Amine-Impregnated Porous Montmorillonite Nanoclays

Montmorillonite nanoclay was studied for its capability of storing carbon dioxide, methane, and nitrogen at elevated pressures. Adsorption data were collected to study and assess the possible applications of montmorillonite to gas storage, as it is available in depleted shale reservoirs. The thermodynamic properties of montmorillonite and its amine impregnated structures were studied in this manuscript. Material characterization via Brunauer–Emmett–Teller analysis, thermogravimetric analysis, Fourier transform infrared and energy dispersive X-ray spectroscopies, and scanning electron microscopy was carried out on the nanoclay samples followed by low- and high-pressure gas sorption experimental measurements via high-pressure magnetic suspension sorption apparatus at 298 and 323 K isotherms up to 50 bar. Selectivities of each gas on each nanoclay material is calculated based on single gas adsorption measurements and presented in the manuscript. Additionally, heat of adsorption and kinetics of adsorption are calculated and reported