Thermogravimetric Mass Spectrometer Research Articles

Thermal analysis technology to utilize waste biomass and waste heat to produce high-quality combustible gas through simulations and experiments

To ensure the proper utilization of waste biomass (WB) and high-temperature waste heat, this study proposes a new method for obtaining gaseous fuels by pyrolyzing WB and using waste heat in the converter vaporization cooling flue (CVCF). This study is theoretically based on the simulation software Factsage 6.1 and the release patterns of the gaseous products including CO, H2, CH4 and CO2 obtained from waste biomass, were studied at different temperatures and pressures. Thermogravimetric-mass spectrometer (TG-MS) was used to investigate the pyrolysis of WB at heating rates of 5, 10, 15, and 20 °C/min from room temperature to 1400 °C. Kinetics parameters were calculated by using the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models. To investigate the effects of temperature, a settling furnace was also used to simulate CVCF. Thermal decomposition produced the primary gases namely CO, CH4, and H2. Pyrolysis had an average activation energy of 183.29 kJ/mol. As the temperature increased from 800 °C to 1200 °C, the CO content increased from 39.7 % to 48.9 % and the H2 content increased from 35 % to 45.1 %. As the temperature rose from 800 to 1200 °C, the lower heating value (LHV) increased from 11.38 to 12.05 MJ/Nm3. The findings primarily confirmed the feasibility of injecting biomass into the CVCF to generate gaseous fuels from waste heat.

Pyrolysis temperature-dependent carbon retention and stability of biochar with participation of calcium: Implications to carbon sequestration

Converting biomass waste into biochar by slow pyrolysis with subsequent soil amendment is a prospective approach with multiple environmental benefits including soil contamination remediation, soil amelioration and carbon sequestration. This study selected cow manure as precursor to produce biochar under 300 °C, 400 °C, 500 °C and 600 °C, and a remarkable promotion of carbon (C) retention in biochar by incorporation of exogenous Ca was achieved at all investigated pyrolysis temperatures. The C retention was elevated from 49.2 to 68.3% of pristine biochars to 66.1–79.7% of Ca-composite biochars. It was interesting that extent of this improvement increased gradually with rising of pyrolysis temperature, i.e., doping Ca in biomass promoted pyrolytic C retention in biochar by 16.6%, 23.4%, 29.1% and 31.1% for 300 °C, 400 °C, 500 °C and 600 °C, respectively. Thermogravimetric-mass spectrometer (TG-MS) and X-ray photoelectron spectroscopy (XPS) showed that Ca catalyzed thermal-chemical reactions and simultaneously suppressed the release of small organic molecular substances (C2–C7) via physical blocking (CaO, CaCO3, and CaClOH) and chemical bonding (CO and OC–O). The catalyzation mainly occurred at 200–400 °C, while the suppression was more prominent at higher temperatures. Raman spectra and 2D FTIR analysis on biochar microstructure showed that presence of Ca had negative influence on carbon aromatization and thus weakened biochar's stability, while increasing pyrolysis temperature enhanced the stability of carbon structure. Finally, with integrating “C retention” during pyrolysis and “C stability” in biochar, the maximum C sequestration (56.3%) was achieved at 600 °C with the participation of Ca. The study highlights the importance of both Ca and pyrolysis temperature in enhancing biochar's capacity of sequestrating C.

Facile crosslinking of polybutadienes via triazoline heterocyclics: Deciphering mechanism and structural‐property relations

Chain‐end functionalized polybutadiene polymers have widespread application in composite solid propellants (CSP). Curing of these polymers is effected using the reactions at the terminal groups with isocyanates or aziridines if the functional groups are hydroxyl or carboxyl respectively. The high toxicity of isocyanates and aziridines demands alternate cure methods. A facile reaction, devoid of any side reactions is the most desirable one. The large number of double bonds in polybutadienes is favorable for 1, 3 ‐dipolar addition reaction with an azide to yield triazolines. The mechanistic aspects of the uncatalyzed and copper‐mediated azide‐alkene reaction have not been explored previously. The present study focuses on elucidation of the reaction using model compounds of polybutadiene namely trans 3‐hexene, cis‐3 hexene and 3‐methyl pentene which mimic the microstructure of polybutadienes. The paper presents the elucidation of the mechanism using density functional theory (DFT) calculations, detailed reaction pathway and its experimental validation using Fourier transform infrared (FTIR) spectroscopy and 13C nuclear magnetic resonance (NMR) spectroscopy. DFT studies indicate that the activation barrier of 63.8 to 85 kJ/mol for the uncatalyzed reaction. In the copper catalyzed reaction, it diminishes to the range of 18.1 to 33.0 kJ/mol. The thermal decomposition aspects of the cured triazoline system were evaluated using thermogravimetric‐mass spectrometer (TG‐MS). The binder undergoes single stage decomposition in the temperature regime of 278°C‐534°C which is lower than that reported for polyurethane‐polybutadienes. The decomposition reaction yields more volatile products like nitrogen, carbon dioxide, 1,4 butadiene and 4‐vinylcyclohexene, conducive for propellant applications.

Thermogravimetric study of the kinetics and characteristics of the pyrolysis of pulverized coal

Simultaneous thermogravimetric-mass spectrometric (TG-MS) analyzer was used to investigate the pyrolysis characteristics and gas generation rule of three coal samples. Results indicated that Jing-mei (JM), Xinjiang-mei (XM), and Yan-mei (YM) coals had similar pyrolysis characteristics and gas generation law. Their pyrolysis process could be roughly divided into three stages. YM had the highest weight loss and gas generation rates among all the samples. CO and CO2 components in the escaping gas continued to increase when the temperature reached 800 °C. Coats–Redfern method was employed to calculate the activation energy of three kinds of coal at four temperature stages with different mode functions. The activation energy of the four stages of JM pyrolysis was 33.3 kJ mol−1, 2.66kJ mol−1, 88.51kJ mol−1, and 33.26 kJ mol−1. The result of XM pyrolysis was 51.29 kJ mol−1, 6.84 kJ mol−1, 47.38 kJ mol−1, and 15.65 kJ mol−1. Calculations of XM pyrolysis were 51.35 kJ mol−1, 5.11 kJ mol−1, and 117.49 kJ mol−1, 31.15 kJ mol−1 respectively.

Synthesis of hydroxylated fatty amide from underutilized seed oil of Khaya senegalensis: a potential green inhibitor of corrosion in aluminum

BackgroundCorrosion is a serious problem all over the world. Most currently used approach to control corrosion have short comings which necessitates the search for novel materials that are green, cheap, from renewable source, and eco-friendly that can be used to combat this problem of corrosion control.MethodKhaya senegalensis fatty hydroxylamide (KSFA) was synthesized from K. senegalensis seed oil via simple reaction route involving esterification, transesterification, hydroxylation, and amidation reaction. KSFA was characterized using Fourier-transform infrared (FTIR), nuclear magnetic resonance (1HNMR), CHN elemental analyzer, particle size distribution (PSD), X-ray diffractometer, zeta potential, thermogravimetric analysis (TG), thermogravimetric-mass spectrometer (TG-MS), and scanning electron micrograph (SEM) coupled with energy dispersion spectroscopy (EDS). Inhibitory effect of KSFA on corrosion of aluminum (Al) in 0.5 M HCl was studied at different concentrations of KSFA and temperatures using weight loss method.ResultResult from gas chromatography (GC) revealed oil of K. senegalensis to predominantly contain C18:1 (68.46%) fatty acid. Hydroxyl and amide functional groups present in KSFA were confirmed by FTIR and 1HNMR. TG analysis revealed loss in mass around 80–190, 200–450, and above 450 °C while TG-MS revealed five different masses with m/z values 16, 17, 18, 28, and 44. Corrosion inhibition capacity of KSFA was by surface adsorption, which is spontaneous, and physisorption and described by Langmuir isotherm. The corrosion inhibition efficiency of KSFA increased with increase in its concentration while its corrosion rate reduced with increase in concentration.ConclusionThe inhibition efficiency of 90.43% exhibited by KSFA and the fact that KSFA was synthesized via non-hazardous process from a renewable sourced biomass is an indication that KSFA is a potential green and efficient inhibitor of corrosion in aluminum. KSFA is simple to use as an inhibitor and easy to prepare.

(Co-)combustion of additives, water hyacinth and sewage sludge: Thermogravimetric, kinetic, gas and thermodynamic modeling analyses

Additives and biomass were co-combusted with sewage sludge (SS) to promote SS incineration treatment and energy generation. (Co-)combustion characteristics of sewage sludge (SS), water hyacinth (WH), and 5% five additives (K2CO3, Na2CO3, Mg2CO3, MgO and Al2O3) were quantified and compared using thermogravimetric-mass spectrometric (TG-MS) and numerical analyses. The combustion performance of SS declined slightly with the additives which was demonstrated by the 0.03-to-0.25-fold decreases in comprehensive combustibility index (CCI). The co-combustion performed well given the 0.31-fold increase in CCI. Kinetic parameters were estimated using the Ozawa-Flynn-Wall (OFW) and Kissinger-Akahira-Sunose (KAS) methods. Apparent activation energy estimates by OFW and KAS were consistent. The addition of K2CO3 and MgCO3 decreased the weighted average activation energy of SS. Adding K2CO3 to the blend reduced CO2, NO2, SO2, HCN and NH3 emissions. CO2, NO2 and SO2 emissions were higher from WH than SS. Adding WH or K2CO3 to SS increased CO2, NO2 and SO2 but HCN and NH3 emissions. Based on both catalytic effects and evolved gases, K2CO3 was potentially an optimal option for the catalytic combustion among the tested additives.

Environmental mitigation of sludge combustion via two opposite modifying strategies: Kinetics and stabilization effect

Nowadays, environmental mitigation remains a key issue challenging sludge combustion toward its clean utilization. Herein, two opposite additives, CaO and kaolin, representing two different strategies, were employed for environmental mitigation of sludge combustion. An advanced TG-MS (thermogravimetric-mass spectrometer) system was used. The online MS analysis indicated that kaolin remarkably decreased the release of NOx whereas the fixation effect of CaO on SO2 was more pronounced. Furthermore, the experiments using a fixed tube furnace proved that overall kaolin had a better role controlling volatility of trace elements (Cr, Ni, Cu, Zn, Pb, As and Ba) than CaO and we found that the fixation mechanism of CaO changed at 750 °C, whereas that of kaolin changed at 500 °C. Then the kinetics of the various stages during sludge combustion were investigated. We found that low temperature stages were along with the formation of new phases, whereas, at high temperatures, the diffusion could be rate-controlling step. The present study thus provides not only a deep understanding of sludge combustion mechanisms but also two effective modifying strategies toward the environmental mitigation of sludge combustion.

Enhanced CO2 separation performance for tertiary amine‐silica membranes via thermally induced local liberation of CH3Cl

A facile method for the fabrication of amine‐silica membranes with enhanced CO2 separation performance was proposed via the thermally induced liberation of small molecules from quaternary ammonium salt. Quaternary ammonium‐silica (QA‐SiO1.5) xerogel powders/films were fabricated via sol‐gel processing and their thermal stability was systematically studied using thermogravimetric mass spectrometer, Fourier transform infrared, energy dispersive spectroscopy, and positron annihilation lifetime spectroscopy analysis. CO2 sorption performances of QA‐SiO1.5 derived xerogel powders were quantitatively compared after assigning their relevant parameters to a dual‐mode sorption model. The gas permeation performances of membranes derived from QA‐SiO1.5 were evaluated in terms of kinetic diameter and temperature dependence of gas permeance, and activation energy (Ep) required for gas permeation. The results indicate that liberation of the CH3Cl molecules from these membranes significantly improved both CO2 permeation and CO2/N2 separation capabilities. Therefore, the present study provides insight that should be useful in the development of high‐performance CO2 separation membranes via the effect of the thermally induced liberation of small molecules. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1528–1539, 2018

Thermal Characteristics of Conversion-Type FeOF Cathode in Li-ion Batteries

Rutile FeOF was used as a conversion-type cathode material for Li-ion batteries. In the present study, 0.6Li, 1.4Li, and 2.7Li per mole lithiation reactions were carried out by changing the electrochemical discharge reaction depth. The thermal characteristics of the FeOF cathode were investigated by thermogravimetric mass spectrometric (TG-MS) and differential scanning calorimeter (DSC) systems. No remarkable HF release was detected, even up to 700 °C, which indicated a low toxic risk for the FeOF cathode. Changes in the thermal properties of the FeOF cathode via different conversion reaction depths in the associated electrolyte were studied by changing the cathode/electrolyte ratio in the mixture. LiFeOF was found to exothermically react with the electrolyte at about 210 °C. Similar exothermic reactions were found with charged FeOF cathodes because of the irreversible Li ions. Among the products of the conversion reaction of FeOF, Li2O was found to exothermically react with the electrolyte at about 120 °C, which induced the main thermal risk of the FeOF cathode. It suggests that the oxygen-containing conversion-type cathodes have a higher thermal risk than the oxygen-free ones, but controlling the cathode/electrolyte ratio in cells successfully reduced the thermal risk. Finally, the thermal stability of the FeOF cathode was evaluated in comparison with FeF3 and LiFePO4 cathodes.

Influence of catalysts on co-combustion of sewage sludge and water hyacinth blends as determined by TG-MS analysis

Effects of the three metal carbonates (K2CO3, Na2CO3, and MgCO3) were quantified on catalytic co-combustion of the sewage sludge and water hyacinth (SW) blend using a thermogravimetric-mass spectrometric (TG-MS) analysis and kinetics modeling. The main dominating steps of the catalysts were the organic volatile matter release and combustion stage. Weighted mean values of activation energy (Em) were estimated at 181.18KJ·mol−1, 199.76KJ·mol−1, 138.76KJ·mol−1, and 177.88KJ·mol−1 for SW, SW+5% K2CO3, SW+5% Na2CO3, and SW+5% MgCO3, respectively. The lowest Em occurred with SW+5% Na2CO3. Overall, catalyst effect on co-combustion appeared to be negligible as indicated by Gibbs free energy (ΔG). The normalized intensities of SW+MgCO3 were strongest. The addition of Na2CO3 and MgCO3 to SW increased flue gases emissions (CO2, NO2, SO2, HCN, and NH3) of SW, whereas the addition of K2CO3 to SW reduced flue gases emissions from the entire combustion process.

Hydrogen Evolution during Devolatilization To Predict Coking Potential of Metallurgical Coals

Evolution of hydrogen during the plastic state is a key parameter in coke making for the production of quality coke. Based on this phenomenon, a new devolatilization method has been developed for accessing the coking property of coals using the evolution of H2 during thermogravimetric–mass spectrometer (TG-MS) analysis. Four coals having different coking potentials, commonly used in steel industries, were considered. The investigation was performed at temperatures up to 1100 °C in an argon atmosphere under a constant heating rate of 3 °C/min to simulate the coking environment. Nonisothermal kinetics is considered as a good indication of different reaction regimes during pyrolysis, which is generally done through TGA alone. In this study evolution of H2 is used to develop nonisothermal kinetics through a new quantification approach. Finally, a definite and more generic correlation was established, based on H2 enrichment in volatiles around specific temperature zones, for measuring the exact coking behavior...

Preparation of activated carbon-metal (hydr) oxide materials by thermal methods. Thermogravimetric-mass spectrometric (TG-MS) analysis

Activated carbon (AC)-metal (hydr) oxide (MO) materials prepared by wet impregnation of a commercial AC with Al3+, Fe3+, Zn2+, SnCl2, TiO2 and WO42− in water at pH between 1.37 and 9.54 in two successive soaking and oven-drying steps are analysed by thermogravimetry-mass spectrometry (TG-MS) between 25 and 900°C. Under identical conditions, a blank sample (ACB) was first prepared using deionized water and then thermally analyzed. The mass loss in the TG analysis is 1.35wt% for AC, 2.12wt% for ACB, and between 2.47 and 23.20wt% for the AC-MO materials. For these materials, it depends on the impregnation agent and varies by SnCl2>Fe3+>Al3+>Zn2+>WO42−>TiO2. The number of thermal effects giving off CO2 and CO is larger with the Al3+, Fe3+ and Zn2+ ions than with SnCl2, TiO2 and WO42−. It is so in particular for CO2 with the Fe3+ ion and for CO with the Al3+ ion. In general, the release of CO at high temperature has been associated with the carbothermal reduction of metal oxides. As a result of the reaction low-melting point metals such as Al, Zn and Sn, unlike Fe and W, are formed which vaporize and thereby contribute to the mass loss. Only with Fe3+ and TiO2, the amount of desorbed water is larger by dehydroxylation than by dehydration. The masses of evolved H2O, CO2 and CO are by far higher with SnCl2, whereas they are lower with TiO2 and WO42−.

Synthesis, Structure and Thermal Property of a 3D Coordination Polymer [Sr(BDC)(H<sub>2</sub>O)

The solvothermal reactions of Sr(NO3)2 with 1,4-benzenedicarboxylic acid (BDC) in a mixture of H2O/N,Nʹ-dimethylformamide (DMF) resulted in a novel coordination polymer, [Sr(BDC) (H2O)] (1), which was characterized by single crystal and variable temperature powder X-ray diffraction (VTPXRD), elemental analysis, infra-red (IR) spectroscopy, and thermogravimetric-mass spectrometric (TG-MS) analysis. Compound 1 crystallizes in the orthorhombic space group Pbca with a=1.1854(2) nm, b=0.7122 (1) nm, and c=2.0031(4) nm. It is a three-dimensional (3D) framework consisting of zigzag chains that are formed by face-shared SrO8 square antiprisms and bridging BDC ligands. TG-MS and VTPXRD studies revealed that the framework of compound 1 exhibited a high thermal stability.

Mechanistic study of enhanced H2 synthesis in biomass gasifiers with in‐situ CO2 capture using CaO

AbstractBiomass gasification coupled with in situ CO2 removal using CaO is a promising process for the sustainable production of H2. Thermodynamic equilibrium modeling predicts biomass conversion to gas containing up to 81.4 vol % H2 (dry basis). However, in practice, discrepancies between theoretical and experimental results demonstrate the significance of nonequilibrium phenomena. In this context, we have developed a simultaneous thermogravimetric‐mass spectrometric (TG‐MS) technique to study the influence of: (i) heating rate, (ii) CaO loading, (iii) evolved gas residence time, and (iv) reaction atmosphere. The results of this study give insight into the decomposition mechanisms of biomass in the presence of CaO, including the influence of: (i) CO2 removal, (ii) sorbent hydration (Ca(OH)2), (iii) intrinsic heating and swelling effects associated with the exothermic gas–solid absorption reactions, and (iv) the direct catalytic role of CaO for char gasification and tar elimination. © 2008 American Institute of Chemical Engineers AIChE J, 2008

Pyrolysis study of a hydride-sol-gel silica

The thermal behaviour of a sol-gel prepared hydride silica gel (HSiO sample) in the 20-1000°C interval was studied by coupled thermogravimetric-mass spectrometric (TG-MS) analyses carried out at various heating rates. Thermogravimetric curve elaboration allowed the determination of the flex temperatures, corresponding to the maximum release rate of gas-evolved compounds, and to calculate the activation energy of the overall process. The mass spectrometric data, registered in the TG-MS measurements, were treated to discriminate the single reactions accounting for the release of each compound, among which water, dihydrofuran and various silane- and siloxane-derived species. These results were used to calculate the comprehensive activation energy and also those of each of the released species. Different methods of data processing were used to achieve better reliability of calculated activation energies. The discussion focuses on the high extension of kinetic information arising from MS data processing and on the advantage of identifying the contribution of single reactions, although they occur simultaneously during the heating process. In this respect, good agreement was found between the activation energies of the overall process calculated by separately processing TG and MS data. By processing MS data, the same agreement was observed in the comparison between the activation energy calculated for the overall thermal process and in the sum of the weighed activation energies of the reaction of each released compound.

Description of tire pyrolysis by thermal degradation behaviour of main components

In the first part of this work, several straight rubbers (natural rubber, three styrene–butadiene rubbers with different styrene and oil contents and butadiene rubber) are characterized by thermogravimetric/mass spectrometric (TG/MS) analysis. Additionally, the influence of three typical tire additives ZnO, sulfur and carbon black on the thermal degradation of the straight rubbers is analyzed by TG/MS experiments. In the second part, rubber mixtures and tire parts are investigated by TG/MS and gaschromatographic/mass spectrometric (GC/MS) measurements. It turned out that the GC/MS spectra of the volatile pyrolysis products of rubber mixtures can be composed from the spectra of their rubber components. The multi-step DTG curves of the rubber mixtures can be separated in sections according to the thermal decomposition of their straight elastomers. DTG curves of tire parts are superposed from the DTG curves of their main rubber components, with sufficient approximation of the experimental DTG curves. Furthermore, from TG experiments formal kinetic parameters are derived for the investigated straight rubbers. The thermal decomposition of tire parts can then also be calculated with the formal kinetic parameters for the thermal decomposition of their rubber components.

Effect of Heating Rate on Steam Gasification of Biomass. 2. Thermogravimetric-Mass Spectrometric (TG-MS) Analysis of Gas Evolution

Evolution rates of low-molecular-weight gas products (H2, CH4, CO, and CO2) in pyrolysis and steam gasification of biomass (cellulose and lignin) were studied using thermogravimetric-mass spectrometric (TG-MS) analysis. Total gas yields were measured with a TCD-micro gas chromatograph (micro GC) at heating rates of 1, 10, and 100 K s-1. Steam gasification of biomass demonstrated heating rate effects on gas evolution: 81 wt % of cellulose was converted into tar in pyrolysis; also, slow heating and steam gasification of nascent char occurred above 700 K, evolving H2. Rapid heating significantly enhanced secondary pyrolysis of cellulose tar to yield H2, CO, and CH4. In contrast, char formation at 500−773 K was dominant in lignin pyrolysis. Evolution of H2 and CO2 were significantly increased by steam gasification of char. Insignificant influence of heating rate on carbon and hydrogen yield of lignin was observed. Over 70% of lignin's chemical energy was converted into gas, especially hydrogen.

Sol-Gel Synthesis and Pyrolysis Study of Oxyfluoride Silica Gels

Silicon oxyfluoride materials are synthesized by the sol-gel method using triethoxyfluorosilane as precursor, bearing the Si—F bond. SiO(2−0.5x) F x gel preparation requires peculiar experimental control of hydrolysis and condensation reactions. Maintenance of the Si—F bond during gelling, heating and aging was studied in the case of processes carried out under an argon atmosphere or in air. Fluorine contents in resulting samples were quantified by FT-IR and X-ray photoelectron spectroscopy (XPS); specific surface area and porosity of powdered samples were determined by N2 adsorption. The thermal stability of oxyfluoride gels was studied by thermogravimetric-mass spectrometric (TG-MS) coupled analyses during heat treatment, under He flow. Mass spectra recorded during principal weight losses indicate the release of variously fluorinated silicon species resulting from Si—F/Si—O exchange reactions. The evolution of these species was observed at different temperatures, depending on gelling conditions. In particular, degradation of ≡Si—F moieties was prominent for gels aged in air, whereas samples processed under an argon atmosphere preserve the ≡Si—F bond up to 300°C.

速度制御熱分析（ＣＲＴＡ）法および同時ＴＧ‐ＭＳ法を用いた高分子の熱分解反応速度論

Kinetic study in thermal decomposition of polymeric materials has been examined by means of simultaneous thermogravimetric-mass spectrometric (TG-MS) analysis and controlled-rate thermogravimetry (CRTG) which belongs to controlled-rate thermal analysis (CRTA). We proposed rate-jump control (RJC) method in which the preselected two decomposition rates are controlled alternately at the interval of the constant weight loss percentage, in order to estimate the apparent activation energy without preliminary knowledge of the actual mechanism. The reaction models governing the thermal decomposition of poly(caproamide) (Nylon-6) and poly-(methyl methacrylate) (PMMA) will be easily attributed by the shape of curves observed from constant decomposition rate control (CDRC) experiments. The each kinetic parameter sets were estimated from the RJC data and the evolved gas components obtained from simultaneous TG-MS system, and the corresponding kinetic models were reaction of a random scission in the main chain with L = 2 (L is the smallest polymerization degree of polymer that does not evaporate) and 1.5 order reaction of depolymerization, respectively.It is concluded that the combination of analytical techniques by the thermogravimetric curves obtained from CRTG and chemical species obtained from TG-MS, is capable of establishing the uniqueness of kinetic parameters and reaction models, when dealing with thermal decomposition reaction in polymers.

Thermogravimetric/mass spectrometric characterization of the thermal decomposition of (4‐O‐methyl‐D‐glucurono)‐D‐xylan

AbstractA thermogravimetric/mass spectrometric (TG/MS) system was used to characterize the thermolysis reactions of (4‐O‐methyl‐D‐glucurono)‐D‐xylan. The mass spectrometric peaks, measured as function of time, were attributed to water, methanol, carbon monoxide, carbon dioxide, formaldehyde, formic acid, acetic acid, acetone, acrolein, 2‐furaldehyde, and 3‐hydroxy‐2‐penteno‐1,5‐lactone. The time derivative of the thermogravimetric curve (DTG) consisted of two partially overlapping peaks, indicating a multistep mechanism. The mass spectrometric intensities of the peaks assigned to methanol and 2‐furaldehyde coincided with the first DTG peak, suggesting that the first DTG peak represents both dehydration and fragmentation pathways. Methanol, water, formyl group, and carbon dioxide contributed to both of the DTG peaks. This indicates that the dehydration, decarboxylation, and decarbonylation took place in two steps. The compounds observed only in the second DTG peak and later (acetone, formic acid, formaldehyde, acrolein, acetic acid, and 3‐hydroxy‐2‐penteno‐1,5‐lactone) are probably products of reactions which occur after the collapse of the original polysaccharide structure.