DIFFERENTIAL THERMAL ANALYSIS METHODS AND TECHNIQUES

1953 ◽  
Author(s):  
Joseph A. Pask ◽  
Maurice F. Warner
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Analysis Methods ◽  
Methods And Techniques

Characterization of Crude Oil for Fireflooding Using Thermal Analysis Methods

1977 ◽  
Vol 17 (03) ◽  
pp. 211-218 ◽  
Author(s):  
J.H. Bae
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crude Oil ◽  
Combustion Process ◽  
Crude Oils ◽  
Temperature Oxidation ◽  
Analysis Methods ◽  
Oxidative Behavior ◽  
Fuel Deposition ◽  
Flowing Atmosphere

Abstract To study the thermo-oxidative behavior of crude oils, differential thermal analysis and thermogravi-metric instruments were developed that could be used at 1,000 degrees F and 1,000 psig in a flowing atmosphere. Subsequently, 15 crude oils, ranging from 6 to 38 degrees API gravity, were used at pressures of 50, 500, and 1,000 psig. Both nitrogen and air atmospheres were used in the experiments. The results show that crude oils can be grouped into three types according to their thermo-oxidative characteristics. The gravity of the crude oils does not correlate well with these patterns. It is also shown that the dependence of fuel availability on temperature and pressure varies with different crude oils. Furthermore, crude oils generally gain weight in an air atmosphere in relation to the evaporation curve obtained in a nitrogen atmosphere at both low and high temperatures. This shows that the availability of oxygen at low temperatures changes drastically the quality and quantity of available fuel. The heat generated by low-temperature oxidation might be significant in fireflooding. Finally, a qualitative correlation of the results of thermal analysis with those of combustion-tube tests is indicated. Introduction A substantial investigative effort has been made over the years, bob in the laboratory and in the field to understand the mechanisms of fireflooding, and a general understanding of the process now exists. However, the many factors that affect the process and the interrelationships of these factors process and the interrelationships of these factors make the process a complicated one. This also makes it difficult to predict the behavior of combustion by simple means. The linear laboratory combustiontube test appears to be fairly standard in the industry. Even in this type of experimental approach translation of the linear tube-test results to the field is not always possible. Two of the most important factors in the combustion process are fuel deposition and oxidation. Unfortunately, these presently are also the factors about which the least is known. Fuel for the process is usually thought to be the heavy fraction of crude oil held in the pores after the fluid displacement. The rate of advance and the peak temperature of the combustion front depend on the amount of fuel, availability of oxygen, and the rate of fuel oxidation. In fact, fuel deposition and oxidation govern the ability to sustain forward combustion and strongly influence the economics of a combustion project. Attempts have been made to use the thermal analysis methods in connection with forward combustion. In particular, differential thermal analysis (DTA) was used to study the oxidation of crude oil in porous media. DTA is a technique wherein energy changes in a substance are detected and measured as a function of time or temperature. In practice, the temperature of the sample is compared continuously with a reference material temperature. The difference in temperature is recorded. Another thermal analysis method is thermogravimetric analysis (TGA). In this technique, a sample is weighed continuously as it is heated at a constant rate. The resulting curve of weight change vs time or temperature gives the TGA thermogram. The objective of this work was to study the thermo-oxidative behavior of crude oils using both DTA and TGA techniques to gain some insight into the combustion process, especially the fuel deposition and oxidation. At the same time, we hoped to obtain information useful for predicting the thermal behavior of crude oil in the combustion process. Toward this goal DTA and TGA process. Toward this goal DTA and TGA equipment was developed that could be used at 1000 degrees F and 1,000 psig in a flowing atmosphere. Fifteen crude oils in a wide gravity range (6 to 38 degrees API) were analyzed, and the results are reported here. EXPERIMENTAL EQUIPMENT For our purposes, it was necessary in the DTA block to have a porous matrix to hold the oil and provisions for flowing gas through the sample at provisions for flowing gas through the sample at pressures up to 1,000 psi. The DTA block used is pressures up to 1,000 psi. The DTA block used is shown schematically in Fig. 1. SPEJ P. 211

Synthesis and structure of novel Ag2Ga2SiSe6 crystals: promising materials for dynamic holographic image recording

RSC Advances ◽  
2016 ◽  
Vol 6 (93) ◽  
pp. 90958-90966 ◽  
Author(s):  
O. V. Parasyuk ◽  
V. V. Pavlyuk ◽  
O. Y. Khyzhun ◽  
V. R. Kozer ◽  
G. L. Myronchuk ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Phase Diagrams ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Holographic Image ◽  
X Ray ◽  
Image Recording ◽  
Analysis Methods ◽  
First Time

Phase diagrams of the AgGaSe2–SiSe2 system were explored by differential thermal analysis (DTA) and X-ray diffraction (XRD) analysis methods for the first time.

Zeolites Fit For A Crown: Probing Host-Guest Interactions with Thermogravimetric Methods

2018 ◽  
Author(s):  
Asel Sartbaeva ◽  
Paul R. Raithby ◽  
Remi Castaing ◽  
Antony Nearchou
Keyword(s):  
Mass Spectrometry ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Petrochemical Industry ◽  
Rational Use ◽  
New Methodologies ◽  
First Time ◽  
Kinetics Of

Through a combination of thermogravimetry, mass spectrometry and differential thermal analysis, we demonstrate for the first time that all four zeolites show experimental differences in their host-guest interactions with 18C6. In addition, we have estimated the kinetics of 18C6 decomposition, which is a technique that has not been applied to zeolites previously. Using these findings as a toolkit, a more rational use of OSDAs can be utilised to prepare designer zeolites. Furthermore, the new methodologies presented herein can be applied to current zeolites, such as MFI-type zeolites used in the petrochemical industry.

PHASE EQUILIBRIUM IN THE AS2TE3-TM2TE3 SYSTEM.

2020 ◽  
Vol 5 (8(77)) ◽  
pp. 65-68
Author(s):  
Teymur Mammad Ilyasly ◽  
Rahman Hasanaga Fatullazade ◽  
Zakir Islam Ismailov ◽  
Nigar Nadir Jafarova
Keyword(s):  
Thermal Analysis ◽  
Solid Solution ◽  
Differential Thermal Analysis ◽  
Phase Equilibrium ◽  
Physicochemical Properties ◽  
Thermal Effects ◽  
Isothermal Annealing ◽  
Intermediate Phase ◽  
Physicochemical Analysis ◽  
Two Phases

The synthesis of alloys of the system was carried out stepwise in rotary furnaces. The synthesis mode was selected based on the physicochemical properties of the elementary components. For homogenization, the alloys were subjected to isothermal annealing at 750 and 1275 K, depending on the Tm2Te3 concentration, for 250 h after homogenization of the alloys, they were subjected to physicochemical analysis. The results of differential thermal analysis showed that reversible thermal effects are observed in the alloys of the system. In alloys in a 1: 1 ratio, a new intermediate phase is formed with a composition corresponding to the TmAsTe3 compound. The homogeneity area is observed in the concentration range 52.5-47.5. It was found that in the concentration range 98.5-52.5 Tm2Te3 there are two phases - a mixture of β and of the solid solution, and in the concentration range of 47.51 mol% Tm2Te3 phases and α are in equilibrium. ) 66 The eutectic has coordinates of 11.5 mol Tm2Te3 at a temperature of 575 K.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

Kinetics of temperature-programmed reactivation of a hydrodesulphurization catalyst

1983 ◽  
Vol 48 (12) ◽  
pp. 3340-3355 ◽  
Author(s):  
Pavel Fott ◽  
Pavel Šebesta
Keyword(s):  
Carbon Dioxide ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Thin Layer ◽  
Kinetic Parameters ◽  
Diffusion Region ◽  
Reaction Heat ◽  
Gaseous Products ◽  
Temperature Programmed ◽  
Kinetics Of

The kinetic parameters of reactivation of a carbonized hydrodesulphurization (HDS) catalyst by air were evaluated from combined thermogravimetric (TG) and differential thermal analysis (DTA) data. In addition, the gaseous products leaving a temperature-programmed reactor with a thin layer of catalyst were analyzed chromatographically. Two exothermic processes were found to take part in the reactivation, and their kinetics were described by 1st order equations. In the first process (180-400 °C), sulphur in Co and Mo sulphides is oxidized to sulphur dioxide; in the second process (300-540 °C), in which the essential portion of heat is produced, the deposited carbon is oxidized to give predominantly carbon dioxide. If the reaction heat is not removed efficiently enough, ignition of the catalyst takes place, which is associated with a transition to the diffusion region. The application of the obtained kinetic parameters to modelling a temperature-programmed reactivation is illustrated on the case of a single particle.

Effect of experimental conditions on the differential thermal-analysis of karnallite type hydrates

1984 ◽  
Vol 49 (12) ◽  
pp. 2770-2775
Author(s):  
Vladimir Z. Poilov ◽  
Jana Ederová ◽  
Antonín Blažek
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Experimental Conditions

Article in Russian

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