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1. Accelerated and Natural Aging of Cellulose-Based Paper: Py-GC/MS Method.

Author

Kaszonyi A, Izsák L, Králik M, and Jablonsky M

Subjects
Gas Chromatography-Mass Spectrometry, Lignin, Temperature, Cellulose chemistry, Pyrolysis
Abstract

Samples of papers artificially (2 to 60 days) and naturally (10, 45, and 56 years) aged were studied by the Py-GC/MS method to identify decomposition products. Possible reaction scenarios for cellulose degradation were developed. One of the degradation products is acetic acid, which can (auto)catalyze the cleavage of cellulose β(1→4)-glycosidic bonds of cellulose polymer chains. However, during 20 s of Py-GC/MS analysis, temperatures of up to 300 °C did not significantly increase or modify the formation of decomposition products of paper components. At 300 °C, the amount of several cellulose decomposition products increased regularly depending on the number of days of artificial aging and natural aging, demonstrated mainly by the generation of 2-furancarboxaldehyde, 5-hydroxymethylfurfural, and levoglucosan and its consecutive dehydration products. No correlation between the amount of lignin decomposition products and the time of aging was found when the pyrolysis was performed at 300 °C and 500 °C. Compounds present in the products of decomposition at 500 °C bear the imprint of the chemical composition of the sampled paper. Pyrograms taken at 300 °C using the Py-GC/MS method can give additional information on the changes in the chemical structure of paper during natural or artificial aging, mainly about the cleavage of β(1→4)-glycosidic bonds during aging.

Published
2022
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3. Preliminary investigation of the microwave pyrolysis mechanism of sludge based on high frequency structure simulator simulation of the electromagnetic field distribution

Author

Xuxin Zhao, Rui Ma, Na-Na Yuan, Shichang Sun, Xianghua Zhang, Lin Fang, Peixin Zhang, Shenzhen Univerisity [Shenzhen], Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), This paper was supported by the Shenzhen Science and Technology Planning Project (Grant Nos. JCYJ20150828113927076, JCYJ20130329113322731), the China National Natural Science Foundation (50906058) and the Natural Science Foundation of SZU (No. 827-000037)., Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Electromagnetic field, Hot Temperature, Environmental Engineering, Materials science, Carbon Compounds, Inorganic, 020209 energy, Microwave pyrolysis, Evaporation, Analytical chemistry, Bioengineering, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, 7. Clean energy, Electromagnetic Fields, [CHIM.GENI]Chemical Sciences/Chemical engineering, Waste Management, Electric field, HFSS simulation, 0202 electrical engineering, electronic engineering, information engineering, Desiccation, Microwaves, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Sewage, Waste management, [SDE.IE]Environmental Sciences/Environmental Engineering, Renewable Energy, Sustainability and the Environment, Silicon Compounds, General Medicine, Thermal conduction, Raw sludge, 6. Clean water, Microwave irradiation, Electric field intensity, SiC sludge, Pyrolysis, Intensity (heat transfer)
Abstract

Under microwave irradiation, raw sludge was pyrolyzed mainly by evaporation of water, with a weight loss ratio of 84.8% and a maximum temperature not exceeding 200 °C. High-temperature pyrolysis of SiC sludge could be realized, with a weight loss ratio of 93.4% and a final pyrolysis temperature of 1131.7 °C. Variations between the electric field intensity distribution are the main reason for the differences of pyrolysis efficiencies. HFSS simulation showed that the electric field intensity of the raw sludge gradually decreased from 2.94 × 10 4 V/m to 0.88 × 10 4 V/m when pyrolysis ends, while that of SiC sludge decreased from 3.73 × 10 4 V/m at the beginning to 1.28 × 10 4 V/m, then increased to 4.03 × 10 4 V/m. The electromagnetic effect is the main factor (r ≥ 0.91) influencing the temperature increase and weight loss of raw sludge. Both the electromagnetic effect and heat conduction effect influenced temperature rise and weight loss of SiC sludge, but the former’s influence was comparatively larger.

Published
2017

4. Ablative thermal protection system under uncertainties including pyrolysis gas composition

Author

Jean Lachaud, Mickael Rivier, Pietro Marco Congedo, Shape reconstruction and identification (DeFI ), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre de Mathématiques Appliquées - Ecole Polytechnique (CMAP), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université de la Nouvelle-Calédonie (UNC), Experiments presented in this paper were carried out using the PlaFRIM experimental testbed, supported by Inria, CNRS (LABRI and IMB), Université de Bordeaux, Bordeaux INP and Conseil Régional d'Aquitaine (see https://www.plafrim.fr/)., Centre de Mathématiques Appliquées - Ecole Polytechnique (CMAP), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)

Subjects
[PHYS.PHYS.PHYS-FLU-DYN]Physics [physics]/Physics [physics]/Fluid Dynamics [physics.flu-dyn], 0209 industrial biotechnology, Hypersonic speed, Nuclear engineering, Heat and mass transfer, Aerospace Engineering, 02 engineering and technology, 01 natural sciences, 010305 fluids & plasmas, 020901 industrial engineering & automation, Atmospheric entry, Space Shuttle thermal protection system, 0103 physical sciences, Environmental science, Anchored-ANOVA, Gas composition, Porous medium, Porosity, Material properties, Pyrolysis, Uncertainty quantification, Thermal protection systems, Pyrolysis Carbon/phenolic composites
Abstract

International audience; Spacecrafts such as Stardust (NASA, 2006) are protected by an ablative Thermal Protection System (TPS) for their hypersonic atmospheric entry. A new generation of TPS material, called Phenolic Impregnated Carbon Ablator (PICA), has been introduced with the Stardust mission. This new generation of low density carbon-phenolic composites is now widely used in the aerospace industry. Complex heat and mass transfer phenomena coupled to phenolic pyrolysis and pyrolysis gas chemistry occur in the material during atmospheric entry. Computer programs, as the Porous material Analysis Toolbox based on OpenFoam (PATO) released open source by NASA, allow to study the material response. In this study, a non-intrusive Anchored Analysis of Variance (Anchored-ANOVA) method has been interfaced with PATO to perform low-cost sensitivity analysis on this problem featuring a large number of uncertain parameters. Then, a Polynomial-Chaos method has been employed in order to compute the statistics of some quantities of interest for the atmospheric entry of the Stardust capsule, by taking into account uncertainties on effective material properties and pyrolysis gas composition. This first study including pyrolysis gas composition uncertainties shows their key contribution to the variability of the quantities of interest.

Published
2019

5. The effects of catalysts on the conversion of organic matter and bio-fuel production in the microwave pyrolysis of sludge at different temperatures

Author

Xianghua Zhang, Xiaofei Huang, Rui Ma, Yang Zhou, Xuxin Zhao, Peixin Zhang, Shichang Sun, Lin Fang, Shenzhen Univerisity [Shenzhen], Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), This paper was supported by the China National Natural Science Foundation (50906058), the Natural Science Foundation of SZU (No. 827-000037), and the Shenzhen Science and Technology Planning Project (Grant Nos. JCYJ20150828113927076, JCYJ20130329113322731)., Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Environmental Engineering, Materials science, Hot Temperature, 020209 energy, Bio-fuel, Catalytic microwave pyrolysis, Bioengineering, 02 engineering and technology, Activation energy, 010501 environmental sciences, Fluid catalytic cracking, CaO catalyst, 01 natural sciences, 7. Clean energy, Ferric Compounds, Sludge, Catalysis, [CHIM.GENI]Chemical Sciences/Chemical engineering, 0202 electrical engineering, electronic engineering, information engineering, Organic matter, Microwaves, Waste Management and Disposal, 0105 earth and related environmental sciences, chemistry.chemical_classification, Waste management, Sewage, Renewable Energy, Sustainability and the Environment, [SDE.IE]Environmental Sciences/Environmental Engineering, Temperature, General Medicine, [CHIM.CATA]Chemical Sciences/Catalysis, Cracking, chemistry, Chemical engineering, 13. Climate action, Biofuel, Yield (chemistry), Biofuels, Pyrolysis, Fe(2)O(3) catalyst
Abstract

International audience; Adding catalyst could improve the yields and qualities of bio-gas and bio-oil, and realize the oriented production. Results showed that the catalytic gas-production capacities of CaO were higher than those of Fe2O3, and the bio-gas yield at 800°C reached a maximum of 35.1%. Because the polar cracking active sites of CaO reduced the activation energy of the pyrolysis reaction and resulted in high catalytic cracking efficiencies. In addition, the quality of bio-oil produced by CaO was superior to that by Fe2O3, although the bio-oil yield of CaO was relatively weak. The light bio-fuel oriented catalytic pyrolysis could be realized when adding different catalysts. At 800°C, CaO was 45% higher than Fe2O3 in aspect of H2 production while Fe2O3 was 103% higher than CaO in aspect of CH4 production. Therefore, CaO was more suitable for H2 production and Fe2O3 was more suitable for CH4 production.

Published
2017