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This article describes the use of microwave irradiation in the synthesis of bis(cyclo carbonate) compounds (BCCs) in bulk (without solvent) from carbon dioxide capture using an epoxidized compound—a commercial epoxy resin—and compares this process to the conventional method. CO2 cycloaddition to epoxides is an ecological and efficient method for the formation of bis(cyclic carbonates). Moreover, the introduction of gas into the reaction mixture was carried out at atmospheric pressure with a controlled flow rate, which is advantageous from an economic point of view. Progressive structural changes and the presence of characteristic chemical groups were monitored using attenuated total reflectance infrared spectroscopy with Fourier transform. The obtained crude products were purified to obtain three fractions, which were subjected to detailed structural analysis using FT-IR and 13CNMR. The formation of the main product with two cyclic carbonates was confirmed. The presence of monomers, dimers and trimers in individual fractions as well as their thermal stability were determined, and the molecular masses in individual fractions were determined using gel permeation chromatography (GPC). [ABSTRACT FROM AUTHOR]

Gas hydrates are inclusion compounds of a water backbone that encloses gaseous molecules. Thanks to their applications in gas recovery, carbon capture and storage, gas storage, and flow assurance, generating high quality data and predictions of their properties is paramount. A review of novel techniques using first principles density functional theory and molecular dynamics simulations methods coupled to auxiliary simulations methods is presented herein. Structure I (sI), structure II (sII), and structure H (sH) hydrates have been studied extensively, with studies of their material strength showing that it is often misleading to use the properties of ice instead of the difficult‐to‐determine gas hydrate properties. Key differences between the three structures and their possible guests are presented. The interfacial properties of gas hydrates display key behaviours that control nucleation and growth, which are important phases in controlling and monitoring their formation. Gas hydrate thermal properties are also examined, with key differences existing between guests and some unusual alignment in the cages shown for carbon dioxide, ethane, and ethylene oxide sI hydrates. First principles infrared spectroscopy is also examined, with techniques showing that these signatures can be tied to and predict material properties to improve the speed of analysis. Therefore, by quantifying, modelling, predicting, and explaining their formation and dissociation, and linking these to their thermal, material, and interfacial properties, a database of reliable data for science and engineering methods and applications is formed to provide a basis for further work. [ABSTRACT FROM AUTHOR]

• Critical properties, heat capacities, and thermal diffusivities were measured. • The thermal conductivities of the compounds under study were calculated. • Thermal properties were determined for liquid phase at atmospheric pressure. • Glymes are used for capture of CO 2 , H 2 S, and other gases. The critical temperatures, critical pressures, and thermal diffusivities have been measured for mono-, di-, tri-, and tetraglymes, compounds that are used for pre- and post-combustion capture of CO 2 , H 2 S and other gases. The critical properties have been measured using the pulse-heating method applicable to thermally unstable compounds. The combined relative expanded uncertainties with the 0.95 level of confidence are 0.01 and 0.03 for the critical temperature and pressure, respectively. The acentric factors of the compounds have been calculated based on the experimental data. The critical properties of these compounds have also been calculated by the group contribution methods of Wilson and Jasperson, Nannoolal et al., and Hukkerikar et al. in two variants. The Wilson/Jasperson technique provides the best estimation of the critical temperature and the Hukkerikar et al. one gives the best results for the critical pressure. The thermal diffusivities of glymes have been measured at atmospheric pressure in the temperature range from 303.15 to 353.15 K. The thermal conductivities of glymes have been calculated from the experimental data. The temperature dependence of the thermal diffusivities and thermal conductivities has been approximated by linear polynomials. The experimental thermal conductivities of glymes have been compared with those estimated by the methods of Govender et al. and Liu et al. The method of Govender et al. provides a good estimation of the thermal conductivity of glymes. [ABSTRACT FROM AUTHOR]

Polymers of intrinsic microporosity (PIMs) are among the most promising candidates for the development of novel polymeric gas separation membranes for processes such as carbon capture and storage, natural gas treatment and biogas upgrading. As one of the approaches to optimize their performance, PIMs are functionalized by CO 2 -philic groups to improve the CO 2 separation by the enhancement of specific noncovalent interactions. In this work, we show the preparation of amine-PIM from the archetypal PIM-1, using borane dimethyl sulphide complexes in order to control the degree of conversion. The PIM-1 to amine-PIM-1 conversion was characterized by ATR-IR and NMR analysis. The influence of the amine moiety on the gas transport behaviour was investigated by two complementary techniques: gas permeation measurements by the time lag method and analysis of the sorption kinetics and the equilibrium sorption isotherms by the gravimetric method. Both techniques show that permeability decreases with increasing degree of conversion. The trends in the indirectly calculated solubility confirm those of direct analysis, although quantitative comparison of the two shows fundamental differences. A pressure and temperature study on a fully converted sample indicates that the solution-diffusion model should be expressed in concentration dependent transport parameters to be correct. The experimental work was supported by quantum mechanics studies and by molecular dynamics simulations to confirm the selective non-covalent interaction of CO 2 with the amino groups. [ABSTRACT FROM AUTHOR]

In this paper, the structure-property relationships of a clay ceramic with organic additives (biomass and biochar) are investigated to develop an alternative material for thermal energy storage. The firing transformations were elucidated using X-ray pair distribution function analysis, differential scanning calorimetry, and scanning electron microscopy. It was found that the biomass increased the porosity, which resulted in a decrease of the specific heat capacity. On the other hand, the biochar remained in the clay ceramic without any interaction with the clay matrix up to 950°C. The specific heat capacity of the clay ceramic increased from 1.20 to 1.49 kJ/kg·K for a 30 wt% addition of biochar. The clay ceramic with a 30 wt% addition of biochar also conserved a high flexural strength of 11.1 MPa compared to that of the clay ceramic without organic additives (i.e., 18.9 MPa). Furthermore, the flexural strength only decreased by 23% after 100 thermal cycles. The crack growth associated with the thermal fatigue was limited by crack bridging and crack trapping. Hence, the current results suggest that clay/biochar ceramics can be as efficient as molten salts in thermal energy storage with the added benefit of an ease of use in the physical form of bricks. [ABSTRACT FROM AUTHOR]

Biochar thermosequences produced from the charring of poultry manure and freshwater macroalgae feedstocks between 300 and 700 °C were analyzed by pyrolysis-GC-MS to assess the nature of the thermochemical conversion of N-rich feedstocks. With increasing charring temperature (T CHAR ), the products of intact lignin, protein and polysaccharides decreased whereas those of charred aromatic domains (monocyclic and polycyclic aromatic hydrocarbons, benzonitriles) increased. These results are in agreement with thermosequences obtained from lignocellulosic feedstocks under the same analytical conditions. Therefore, we aimed to create a universal proxy of the degree of thermochemical alteration of biochar thermosequences from diverse series of feedstocks (gorse wood, chestnut wood, rice straw, poultry manure, freshwater algae and tannin) using Principal Components Analysis (PCA). From the PCA the relation of pyrolysis products with charring intensity was established and translated to Thermal Stability Indices (TSI p ), which then gave rise to calculations of TSI of the biochars (TSI b ). The TSI p varied only slightly between the different feedstocks suggesting that they could be used in future research to interpret pyrolysis fingerprints for a wide range of different biochars. In addition, TSI b can be used as a thermostability proxy for biochars and were found to be more reliable than other pyrolytic proxies such as the benzene/toluene or naphthalene/C 1 -naphthalenes ratios. This study marks the first attempt to develop a single proxy of stability for biochars at T CHAR from pyrolysis fingerprints using 157 common pyrolysis products. These proxies will provide a simple measure for the usefulness of a biochar for C sequestration and/or soil amelioration. [ABSTRACT FROM AUTHOR]

Green seaweeds from the genus Ulva are a promising feedstock for the production of biochar for carbon (C) sequestration and soil amelioration. Ulva can be cultivated in waste water from land-based aquaculture and Ulva blooms (“green tides”) strand millions of tons of biomass on coastal areas of Europe and China each year. The conversion of Ulva into biochar could recycle C and nutrients from eutrophic water into agricultural production. We produce biochar from Ulva ohnoi , cultivated in waste water from an aquaculture facility, and characterize its suitability for C sequestration and soil amelioration through bio-chemical analyses and plant growth experiments. Two biomass pre-treatments (fresh water rinsing to reduce salt, and pelletisation to increase density) were crossed with four pyrolysis temperatures (300–750 °C). Biomass rinsing decreased the ash and increased the C content of the resulting biochar. However, biochar produced from un-rinsed biomass had a higher proportion of fixed C and a higher yield. C sequestration decreased with increasing pyrolysis temperatures due to the combination of lower yield and lower total C content of biochar produced at high temperatures. Biochar produced from un-rinsed biomass at 300 °C had the greatest gravimetric C sequestration (110–120 g stable C kg −1 seaweed). Biochar produced from un-pelletised Ulva enhanced plant growth three-fold in low fertility soils when the temperature of pyrolysis was less than 450 °C. The reduced effectiveness of the high-temperature biochars (>450 °C) was due to a lower N and higher salt content. Soil ameliorated with biochar produced from pelletised biomass had suppressed plant germination and growth. The most effective biochar for C sequestration and soil amelioration was produced from un-rinsed and un-pelletised Ulva at 300 °C. The green tide that occurs annually along the Shandong coastline in China generates sufficient biomass (200,000 tons dry weight) to ameliorate 12,500 ha of soil, sequester 15,000 t C and recycle 5500 t N into agriculture. We provide clear parameters for biochar production to enable the beneficial use of this biomass. [ABSTRACT FROM AUTHOR]

• High P-T method is proved to be the simplest for ZnCO 3 synthesis. • The crystal structure of impurity-free ZnCO3 was determined by single crystal X-ray diffraction. • Accurate thermal expansion of ZnCO 3 was quantified by single crystal X-ray diffraction at different temperatures. Carbonate materials have been increasingly favoured in terms of the development of flame retardants because of the eternal subject of inorganic carbon sequestration. In this regard, anhydrous zinc carbonate (ZnCO 3) has been deemed as suitable candidate thanks to its excellent flame retardancy compared to traditional hydroxid flame retardant. However, the single crystals growth, accurate characterizations of structural and thermal properties are still not entirely clear from previous studies. With this in mind, ZnCO 3 single crystals were synthesized under high-pressure-temperature conditions (high P-T; 3 GPa and 973 K). The crystal structure of impurity-free ZnCO 3 was determined by means of single crystal X-ray diffraction (XRD). The symmetry was identified as R 3 ¯ c , while the unit cell parameters were a= 4.6463(3) Å and c= 15.0015(11) Å with a final R value of 0.0229. The quantitative analyses of Raman spectrum and infrared absorption indicate that the as-synthesized ZnCO 3 is anhydrous phase. Using Thermogravimetric (TG) / Differential Scanning Calorimeter (DSC) measurements, ZnCO 3 was decomposed in the temperature range of 593–773 K, whereas the heat capacity and the endothermic peak were determined. According to the single crystal XRD from 150 K to 383 K, the thermal expansion coefficients were quantified as α a = 7.90 × 10−6 K−1 and α c = 22.8 × 10–6 K−1, as well as α Vunit cell = 38.8 × 10–6 K−1. These findings provide a precise characterisation and obtain important thermal parameters for the evaluation of its flame retardant properties. [ABSTRACT FROM AUTHOR]

The growing concerns surrounding the rising carbon emissions have impelled the leaders around the world to make efforts to prevent catastrophic manifestations of climate change and global warming. This has led to the resurrection of vegetal concrete building materials using biomass, which have the added benefits of carbon sequestration apart from low embodied energy and renewability. Vegetal concretes are made up of an organic or inorganic binder, and biomass originating from agro-forestry industries such as rice husk, straw bale, hemp, kenaf, cork, and so on. Hemp concrete, a variety of vegetal concrete has been widely researched and is arguably one of the most researched building materials in current times. This paper presents a review of the state-of-the-art of hemp concrete research, with a view to identifying research gaps that shall guide future research for its implementation in the fast-growing green buildings industry. The reviewed aspects of hemp concrete include properties of hemp relevant to construction, binder characteristics, mechanical properties, durability, hygric and thermal properties, environmental credentials, manufacturing processes, and current applications. Several research gaps with regards to the hydraulicity of the binder, strength and durability, and fire resistance of hemp concrete were identified. It was also established that hemp concrete has very low embodied carbon and embodied energy, making it ideal for green building applications. The paper ends with a discussion outlining the need and direction for future research on improving the manufacturing processes and mechanical performance of hemp concrete for wider adoption by the construction industry. [ABSTRACT FROM AUTHOR]