The investigation of gas adsorption on catalysts and more generally solid adsorbents requires a very good interaction between the reactive gas and the powder. The Calvet-type DSC offers the main advantage to work with an open tube detection. This configuration allows the adaptation of different types of experimental crucibles, especially with the possibility of introduction of various types of gas under normal or high pressure. The quartz tube reactor is one option for the applications on catalysts, and more generally for all the adsorption investigations. It makes possible the simulation of the use of a plug-flow fixed bed reactor in heterogeneous catalysis.
Fatty acids, paraffins, organic substances, or inorganic salts can be used as thermal energy storage materials if they have high enough latent heat together with temperatures of phase change adapted to the application. Moreover, the sensible heat, or the heat capacity change over the temperature range of the considered phase change can play an important role, together with the thermal conductivity properties of the material. To be suitable for energy storage, a PCM has to possess the main following specifications:
– a large phase change enthalpy
– a phase change temperature adapted to a given energy storage
– a reproducible phase change
– a limited subcooling
All these parameters are measured via the calorimetric technique. The calorimeters and DSC’s that are able to investigate solid and liquid materials can apply for the determination of latent heat. However there are significant differences in term of sample volume and temperature scanning rate. The choice of these two parameters are of high importance in the thermal investigation of PCM’s. In order to solve the drawbacks of the DSC plate detector, the solution is to use larger amounts of sample and very low scanning rates. These specifications are
offered by the MicroDSC type detectors
Carbon capture and sequestration (CCS) technologies play a critical part in the attempts to reduce the atmospheric carbon dioxide content. Common CO2 sequestration techniques involve direct injection into geologic formations such as depleted oil or gas reservoirs, or deep unminable coal seams. An alternative approach is the injection of CO2 into natural methane
hydrate deposits in ocean sediments. In this case, formation of carbon dioxide hydrates is expected, together with a dissociation of methane hydrates. Examples include:
– SECOHYA (SEparation of CO2 by HYdrate Absorption, France)
– SUGAR (Submarine GAs hydrate Reservoirs, Germany)
Transesterification reaction of colza oil by ethanol using sodium hydroxide as a catalyst could be followed up by calorimetry. The high sensitivity and stability of the instrument allowed to get accurate data even with long term experiments.Three main thermal steps could be noticed: (i) fast direct saponification, (ii) ethanolate diffusion rate-limited step, (iii) Heat production acceleration that may be linked with the hydrolysis of some of the produced ester (could be confirmed by simultaneous spectroscopic methods).
Adapted analytic tools are necessary to achieve the challenges faced while improving biomass pyrolysis processes. While calorimetry allows acquiring key thermodynamic data such as heat of pyrolysis and heat capacity of biomass materials, thermogravimetry allows understanding the chemistry and kinetics of the involved decompositions. By coupling these techniques with gas analysis, the data offered allow selecting the best suited pyrolysis process conditions.
The presented coupled system is a powerful tool to give a full insight of the sorption of gas on various media. It can be adapted to the study of tritium on solid or liquid media and the desorbed gas can be analysed by high resolution mass spectrometry.
The calorimeters described, based on the principle of measuring differential heat flow, are especially dedicated to the nuclear field owing to their sensitivity, their high volume capacity, their measuring accuracy and precision. In our opinion these characteristics make these calorimeters formidable working tools suitable for the classification of both Tritium and Pu materials such as product, scrap & wastes according to their radioactivity which is directly proportional to the thermal power generated by the sample decay.
The accurate characterisation of high surface area sorption materials such as MOF’s is very important for practical applications. It can be done with a volumetric Sievert’s technique and thermal analysis technique to access to a full range of data. The characterisation methods presented here are not limited to the presented examples and can be extended to all type of solid or liquid media.
The accurate characterisation of hydrogen sorption materials is very important for practical applications. It can be done with a volumetric Sievert’s technique and thermal analysis technique to access to a full range of data. The characterisations methods presented here are not limited to the presented examples and can be extended to all type of solid or liquid media.
Calorimetry has been extensively used to assess the subsequent effect of material exposure to high pressures, it can be noticed that high pressure calorimetry (or calorimetric experiments directly operated at high pressures) could be more widely employed.
The goal of this study is to obtain formation energies (enthalpy and Gibbs free energy) of CCTO (Calcium copper titanate CaCu3Ti4O12 ) using high temperature solution calorimetry and heat capacity measurements.
This present study investigates the CO2 and CH4 sorption on standard coals. The technique described here can be applied to numerous others applications taking advantage of the versatility of the presented sorption rig and attached accessories.
Before scaling up the synthesis of an innovating active principle or of a chemical with unique properties, it is a key issue to make sure that no risk is encountered by the people or the materials involved in the running of this reaction. A major difficulty lies in the fact that stability or hazards tests can hardly be run with industrial time and mass scales.
Heat is involved at different steps in the preparation of foodstuffs (cooking, processing …). When heating, cooling or freezing, the food products undergo different types of transformations: melting, crystallization, oxidation… All these transformations occur in a certain range of temperature and are associated with heat variations.
The symmetrical thermogravimetric technique provides a solution to follow the mass variations with a high accuracy under a controlled atmosphere. It allows the elimination of errors on the mass weighing due to the manipulations, providing a easier and faster way of experimentation. Moreover the thermogravimetric data obtained can be treated for kinetic evaluation of the oxidation or corrosion processes.
The characterization of the sorption of CO2 on the different medias (coal, basalt…) is crucial for the understanding of the mechanisms of safe, stable, and reliable storage of CO2 in geological storage. The Sievert’s technique permits to quantify the CO2 uptake of a solid media. Equilibrium or Kinetic measurements can be done to have a full scope of sorption behaviours. In addition, heat of the different reactions can be collected using calorimeters.
We present a small sample of the experiments that can be obtained with some of our system (from assessing performance to “abuse testing” and of course for the development of new material)
The use of the chemical sorbents is today one of the most popular absorption technique for the CO2 capture in postcombustion techniques. In such an industrial process, the amine solution is introduced at the top of an absorption tower while the exhausted fume containing carbon dioxide is introduced at the bottom. As an intimate contact is reached in the absorption tower, the amine solution chemically absorbs the carbon dioxide from the gaseous stream. Such a process especially requires two types of thermodynamic parameters: gas solubility and enthalpy of absorption. The enthalpy of absorption, according to the amount of absorbed gas and the corresponding heat capacities of solutions, define the temperatures of the fluids when they exit the absorption columns. Flow mixing calorimetry is the ideal technique for measuring such enthalpies of absorption. In order to work under pressure, a dedicated high pressure mixing vessel is adapted to be used on the Setaram C80 calorimeter.
The structural changes of materials are associated with modifications of thermodynamic parameters. Techniques most frequently used for the study of the structural modifications are generally and respectively those of X-Ray diffraction and thermal analysis. However both types of characterization are generally obtained on independent apparatus operated by different operators that does not facilitate the correlation between both types of phenomena. In order to solve this problem, a coupling of time-resolved X-Ray diffraction at both small and wide angles with differential scanning calorimetry is introduced as a new technique that allows simultaneous characterization of thermal and structural properties of a sample. The apparatus called Microcalix is designed for laboratory bench and conventional source. The example of the study of polymorphism is presented as an application.
Two major problems arise when interpreting TG-MS data: firstly, multiple fragmentation peaks can lead to a complex spectrum, especially when a lot of organic species are emitted by the
decomposing substances at the same time. This can be bypassed thanks to new techniques such as FT-ICR (Fourier Transform Ion Cyclotron Resonance) and chemical ionisation.
Secondly, species of different nature and / or conformation but same molecular weight can lead to similar peaks and thus confuse the data interpretation.
Humidity Absorption of a Pharmaceutical Compound. CO2 Absorption of a Drug during Transportation.
Understanding the physical degradation of organic materials and components (pyrolisis, oxidation, dehydration, loss of solvent…) is a major concern today. In this context, advanced technologies, using the coupling of thermal analyzers with other analytical instruments have been developed to study samples of gas emissions during the heating process. Real time monitoring of the compounds is therefore indispensable.The aim of this present work has been to develop innovative coupling between thermogravimetric analyzers and a high resolution compact mass spectrometer (FTICR-MS) with chemical ionization techniques.
The food industry have great interest in precise measurement of CO2 gas sorption properties of well known packaging materials including PET. Such measurements would be a great aid in the development and testing of advanced packaging materials such as those used for soda or sparkling beverages containers.
The wide variety of materials being proposed for hydrogen storage today present a number of different challenges to the researcher from an analytical characterization perspective. These include both evaluating the true performance of the materials for real-world applications as well as understanding the underlying fundamental mechanisms controlling the materials properties.
The usual way to determine the thermodynamic conditions of the formation of hydrates in drilling mud formulations is to use a PVT cell with visual observation and simultaneous temperature and pressure measurements. This technique requires heavy instrumentation and often cannot be used if solid particles are present in the formulation. Calorimetry is another way to determine compositions, dissociation enthalpies and heat capacities of hydrates. In order to work under high pressure, an innovative methodology (patent of the French Institute of Petroleum) has been developed using High Pressure MicroDSC to determine the thermodynamic properties and kinetics of gas hydrate formation. This technique allows the detection of phase transitions versus time, temperature and pressure.
State-of-the-art characterization of the hydrogen storage properties of advanced materials requires specialized measurement techniques and equipment for making a variety of measurements including: Pressure-Composition Isotherms (PCT). The PCTPro-2000 is the most advanced fully automated instrument for measuring gas sorption properties of materials, especially for hydrogen storage materials. It is specifically designed for high precision measurements over a wide range of sample sizes, pressures and temperatures.
Gas hydrates, or clathrate hydrates materials have become the focus of great interest in the development of energy and environment-related technologies. All of these applications require the ability to solve problems related to the rates of formation and decomposition of the hydrates, their gas storage capacities and stabilities. PCTPro-2000 is the most advanced fully automated instrument for measuring gas sorption properties of materials. It is specifically designed for high precision measurements over a wide range of sample sizes, pressures and temperatures appropriate for Hydrate investigations.
Calorimetry allows very precise and easy measurements of nuclear materials without any special preparation of the sample, but the major drawback of the technique is the relatively long time of measurement. This mainly depends on the time of response of the calorimeter, but also the thermal inertia due to the large heat capacity of the container. The problem can be numerically solved using a specific software for a predictive measurement of the calorimetric value.
The calorimetric techniques, and especially DSC, are more and more used for the characterization of food ingredients (fatty compounds, starch, proteins, …) such as glass transition, melting, crystallization, denaturation,… The very high sensitive calorimetry opens a new way of determination when the DSC technique is no more adapted. This technique uses very high sensitive detectors (semiconductors) and allows to work on large amounts of sample (volume available : 1 cm3). Very weak thermal effects such as denaturation of proteins in diluted state, gelification of polysaccharides, are detectable. The calorimetric technique is also adapted for mixing simulations such as dilution, dissolution, wetting, reaction and also enzymatic reactions.