Papers by Keyword: TG

Abstract: A innovative method to simplify calculation the kinetics model is applied to wood pyrolysis. Thermal degradation of basswood was investigated with thermogravimetry. The thermal kinetic TG analysis of basswood under N₂ atmosphere was studied at the heating rate of 10,20, 30, 90K/min. All the TG curves are divided into four parts which are drying, slow pyrolysis, fast pyrolysis, and carbonization. The third one is employed to determine the parameters for around 69% of the total mass loss occurs in this range. The peak of the composition is according with DTG curve. It validate assumption of reaction stage.According to the developed method, the react order, reaction energy and pre-exponential factor are obtained, which are in the range of 2.8~4.3, 101.7~126.6 kJ/mol and 2.3×10⁸~7.0×10¹⁰min^-1, respectively, which are in the range of that reported previously. As a comparison experimental data with calculated data, the well fitting results indicate that this method is appropriate for simulating wood pyrolysis kinetics.

Abstract: The catalyst discarded from fluidized catalytic cracking (FCC) units of heavy oil fractions presents in its composition typically high concentrations of silica and alumina, which give to it the possibility to be used as a pozzolanic material. The pozzolanic activity of a spent FCC catalyst from a Brazilian refinery oil was evaluated by studying the influence of the substitution in different degrees of a type II cement, by this catalytic residue on the hydration process and on the compressive strength of the formed materials. The influence of different particle size fractions of the residue and of its milling process was studied as well. The pozzolanic activity was evaluated by thermogravimetry (TG), derivative thermogravimetry (DTG) and non-conventional differential-thermal analysis (NCDTA). The results show that the chemical pozzolanic activity is enhanced when the sample presents a higher specific surface, as well as, the milling of the residue it is fundamental in order to be accepted and used as a pozzolanic material on partial substitution to cement.

Abstract: Lithium ortho-silicate is a suitable solid sorbent for capturing CO₂. This reversible chemical reaction is applicable to CHP. Reaction rate of Lithium ortho-silicate are studied by TG ( Thermogravimetry) and volumetric method that the influence of heat and mass transfer limitations at packed bed is designed as small as possible. CO₂ adsorption reaction rate depends on the temperature. During continual operation, maximum reaction rate do not decrease for 10cycle and it turned out that the reaction system is repeated with from kept .The adsorbent utilization is higher than 60% at every condition. It turn out that lithium ortho-silicate is applicable to CHP.

Abstract: The cheaper phosphoric acid was uesd to replace the phosphorus oxychloride, starch was used to replace pentaerythritol and water as solvent to synthesize a new low-cost intumescent flame retardant (IFR)—starch phosphate ethylenediamine salts. The structure of the IFR was characterized with infrared spectroscopy. The IFR was used to impart flame retardancy to the Epoxy self-leveling floor (Epoxy Resin, EP) to get the fireproof Epoxy self-leveling floor. The results of test showed that 20% of IFR limit oxygen index of EP/IFR composite reach 31.0%. The results show that flame retardant catalyze the pyrolysis of epoxy resin into charcoal; Vertical burning passed UL94 V-0 rating.

Abstract: Sample polluted soil surrounding Shougang as object, TG, thermal analysis of raw soil and cement raw meal experiments were made, the results show that: the polluted soil contains a variety of PAHs of organic pollutants, the total concentration of PAHs is about 156.39ppm. PAHs contaminated soil can be divided into three stages of weight loss at 850°C: water losing stages, organic matter decomposition stages and inorganic carbonate decomposition stages. With the increase in heating temperature, removal rate of total PAHs in raw soil is high. Using polluted soil as cement siliceous raw material, except naphthalene, acenaphthene, two hydrogen acenaphthene and anthracene, other organic compounds of PAHs have residues at 300°Cand small amounts of phenanthrene have residue at 600°C, means cement raw material has certain adsorption of PAHs pollutants. Therefore, when co processing PAHs polluted soil into the cement kiln, considering should be focused the content of pollutants in flue gas volatilization and C2 raw mill especially.

Abstract: Hemp was treated with guanidine dihydrogen phosphate [GDP] to impart flame retardance. The thermal degradation of the samples were studied by thermogravimetry (TG) and differential thermal analysis (DTA). The flame retardance was determined by LOI. Morphology of the char structure was studied by SEM to obtain information concerning the thermal degradation mechanism. For hemp treated with GDP, which has higher LOI and char yield values, the oxidative decomposition stages include a decomposition stage at lower temperatures (165-240°C) , leading to more carbonaceous residue and small amount of flammable products to get the good flame retardance. The SEM of the chars of hemp treated with GDP also indicate the structure of the charring layer may increase heat insulation, and protect inner matrix materials.

Abstract: A novel cheap macromolecular intumescent flame retardant (IFR), was synthesized. Unsaturated polyester resin (UPR) was modified with IFR to get the flame retardant UPR, whose flammability and burning behavior were characterized by limiting oxygen index (LOI). 22.7% of weight of IFR was doped into UPR to get 28.5 of LOI. The thermal properties of epoxy resins containing IFR were investigated with thermogravimetry (TG). Activation energy for the decomposition of samples was obtained using Kissinger equation. The resultant data show that for UPR containing IFR, compared with UPR, IFR decreased weight loss, thermal stability, increased the char yield, which shows that IFR can catalyze decomposition and carbonization of UPR.

Abstract: Fractionated pyrolysis of biomass and its three main components (viz. hemicellulose, cellulose and lignin) was carried out on a thermogravimetric analyzer, which effectively separated the pyrolysis progress of different compositions. Three temperature ranges of 40-300 °C, 300-400 °C and 400-700 °C were presented with hemicellulose, cellulose and lignin as the dominant component, respectively. Fir contains much more cellulose and lignin than rice straw, and thus the weight loss in 300-400 °C is much higher, as 66.4% of the total weight loss. Rice straw contains more extractives and hemicellulose, resulting in higher mass loss in the early pyrolysis stage of 40-300 °C. The pyrolysis of biomass was predicted by hemicellulose, cellulose and lignin according to the additivity law, and the fractionated pyrolysis showed good performance in the prediction of volatile and residue yields of wood biomass. The interactions of biomass components were revealed to be unneglectable.

Abstract: In this work, the TG/DTA behavior of decabromodiphenyl ether (BDE-209) at nitrogen and air atmosphere by using a thermogravimetric analyzer was investigated. The results showed that both of TG and DTG curves at nitrogen atmosphere are very similarly with that at air atmosphere. About 75 wt% and 25 wt% of total mass loss were observed at the temperature range of about 300-430 °C and about 430-580°C, respectively. It is indicated that the mass loss of BDE-209 during the thermal treamtnet is mainly caused by the evaporation and thermal decomposition.

Abstract: This paper presents the results of dilatometry and DTA analyses performed on a Ni base super alloy sample on which a ZrO₂/20%Y₂O₃ coating was deposited. The tests were done at similar temperatures as those present in a gas turbine engine at the inlet of the turbine. The purpose is to assess how a turbine blade with a ZrO₂/20%Y₂O₃ coating would behave to changes in volume due to temperature and structural changes. The differential thermal analyses and thermo gravimetric analyses were performed on the DTA PT 1600 Linseis installation. The thermal dilatometry was performed on the L75HX XXXX installation.