scholarly journals Study of Thermal Behavior of Moxa Floss Using Thermogravimetric and Pyrolysis-GC/MS Analyses

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Min Yee Lim ◽  
Xinyue Zhang ◽  
Jian Huang ◽  
Liang Liu ◽  
Yutang Liu ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Aromatic Hydrocarbons ◽  
Ignition Temperature ◽  
Herbaceous Plants ◽  
Pyrolysis Gas ◽  
Pyrolysis Products ◽  
Polycyclic Aromatic ◽  
Treatment Safety ◽  
Weight Decrease ◽  
Moxa Floss

Moxa floss is a type of biomass used as the main combustion material in moxibustion, a therapy that applies heat from moxa floss combustion to points or body areas for treatment. Safety concerns regarding moxa smoke have been raised in recent years. Since moxa floss is the source material in moxibustion, its thermal behavior and pyrolysis products would be related to the products formed in moxa smoke. This work aims to understand the thermal behavior of moxa floss and investigate the pyrolysis products generated from moxa floss combustion. Six commercial moxa floss samples of 3 storage years and 10 storage years, and of low, medium, and high ratios, were selected. The kinetic data from moxa floss combustion was carried out by a thermogravimetric analyzer. Pyrolysis-gas chromatography and mass spectroscopy using a gas chromatograph and mass spectrometer equipped with a pyroprobe were used to examine the pyrolysis products. Thermogravimetric profiles for all the samples were overall similar and showed a monotonic weight decrease. The range of intensive reaction temperature occurred between 150°C and 450°C, which was characterized by a major weight loss and accompanied by an exothermal degradation of the main components. The average ignition temperature for the samples of 3 and 10 storage years was 218.3°C and 222.6°C, respectively, which was lower than most herbaceous plants. The identified pyrolysis products include monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, ketones, acids, and alkanes. All were of relatively low intensities of below 5% in relative abundance. No volatiles were detected in the samples of 10 storage years. The relatively low values of ignition temperature suggested that moxa floss is more combustible and can be ignited more easily than other herbaceous plants. This may explain why moxa floss has remained as the preferred material used for moxibustion over the years.

scholarly journals Thermal Transformation of Carbon and Oxygen-Containing Organic Compounds in Sewage Sludge During Pyrolysis Treatment

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2258
Author(s):  
Yanjun Hu ◽  
Yanjun Lu ◽  
Wenchao Ma ◽  
Linjie Wang ◽  
Haryo Wibowo ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Thermal Behavior ◽  
Volatile Compounds ◽  
Organic Compounds ◽  
Thermal Transformation ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Evolved Gas ◽  
Polycyclic Aromatic ◽  
Insight Into

Organic carbon (C) and oxygen (O) contained in sewage sludge strongly impact its thermal behavior during pyrolysis treatment. This study was aimed at getting an insight into the decomposition mechanism of organic compounds containing C and O during sludge pyrolysis using thermo-gravimetric Fourier transform infrared spectroscopy (TG-FTIR) and pyrolysis-gas-chromatography/mass spectrometry (Py-GC/MS) and helpfully improving energy conversion of sewage sludge. The temperature domains of transformation were determined and indications of the main compounds produced during each stage were obtained. Results showed that the volatile compounds that evolved after sludge pyrolysis were mainly distributed into six groups: alkenes, aromatic hydrocarbons, alcohols, aldehydes, phenols and carboxylic acids. Comparison in thermal behavior and composition of the evolved volatile compounds were observed. In the low temperature stage (<350 °C), compounds containing O–C=O accounted for the highest proportion in the evolved gas (55%). Over 350 °C, the production of C=C, –OH, and –C6H5 compounds gradually increased; but little was found of compounds containing O–C=O. Above 550 °C, as thermal chemical reaction involving oxygen-containing groups enhanced, compounds containing O–C=O and –OH tended to disappear, and an increasing amount of macromolecular polycyclic aromatic hydrocarbon was formed. Finally, the thermal transformation pathways of the oxygen and carbon-containing compounds were proposed.

Multi-analytical techniques in characterization and identification of Chinese historical rubbings

2021 ◽  
Author(s):  
Na Yao ◽  
Xiangsheng Zhan ◽  
Qinglin Ma ◽  
Shuya Wei
Keyword(s):  
Aromatic Hydrocarbons ◽  
Staining Method ◽  
Analytical Techniques ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Scientific Support ◽  
Biochemical Compounds ◽  
Polycyclic Aromatic ◽  
Marker Compounds ◽  
Conifer Wood

Abstract For authenticity and conservation purposes, the precious historical rubbings preserved in Wuyuan Museum were studied by multi-analytical techniques including Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS), SEM-EDS and Herzberg staining method. Through Py-GC/MS analyses, five types of constituents could be detected: (1) polycyclic aromatic hydrocarbons from soot; (2) retene and methyl dehydroabietate from tar of conifer wood; (3) marker compounds of egg; (4) additives of menthol and curcumene compounds; (5) biochemical compounds of bark paper. Based on this analytical results, the ink type, binding media and additives in the ink, as well as the fiber origin source of the rubbing paper could be concluded. The materials information of the rubbings obtained through this study could not only provide evidence for its authenticity, but also supply scientific support for its conservation and restoration.

scholarly journals Comparative study of a vitrinite-rich and an inertinite-rich Witbank coal (South Africa) using pyrolysis-gas chromatography

2019 ◽  
Vol 6 (4) ◽  
pp. 621-632
Author(s):  
Ofentse M. Moroeng ◽  
Vimbai Mhuka ◽  
Mathew M. Nindi ◽  
R. James Roberts ◽  
Nicola J. Wagner
Keyword(s):  
Bituminous Coal ◽  
Mineral Matter ◽  
Common Source ◽  
Gas Chromatograph ◽  
Geologic History ◽  
Pyrolysis Gas ◽  
Pyrolysis Products ◽  
Molecular Chemistry ◽  
Polycyclic Aromatic ◽  
The Impact

Abstract This study aims to compare iso-rank vitrinite-rich and inertinite-rich coal samples to understand the impact of coal-forming processes on pyrolysis chemistry. A medium rank C bituminous coal was density-fractionated to create a vitrinite-rich and an inertinite-rich sub-sample. The vitrinite-rich sample has 83 vol% total vitrinite (mineral-matter-free basis), whereas the inertinite-rich counterpart has 66 vol% total inertinite. The vitrinite-rich sample is dominated by collotelinite and collodetrinite. Fusinite, semifusinite, and inertodetrinite are the main macerals of the inertinite-rich sample. Molecular chemistry was assessed using a pyrolysis gas chromatograph (py-GC) equipped with a thermal desorption unit coupled to a time of flight mass spectrometer (MS) (py-GC/MS) and solid-state nuclear magnetic resonance (13C CP-MAS SS NMR). The pyrolysis products of the coal samples are generally similar, comprised of low and high molecular weight alkanes, alkylbenzenes, alkylphenols, and alkyl-subtituted polycyclic aromatic hydrocarbons, although the vitrinite-rich sample is chemically more diverse. The lack of diversity exhibited by the inertinite-rich sample upon pyrolysis may be interpreted to suggest that major components were heated in their geologic history. Based on the 13C CP-MAS SS NMR analysis, the inertinite-rich sample has a greater fraction of phenolics, reflected in the py-GC/MS results as substituted and unsubstituted derivatives. The greater abundance of phenolics for the inertinite-rich sample may suggest a fire-related origin for the dominant macerals of this sample. The C2-alkylbenzene isomers (p-xylene and o-xylene) were detected in the pyrolysis products for the vitrinite-rich and inertinite-rich samples, though more abundant in the former. The presence of these in both samples likely reflects common source vegetation for the dominant vitrinite and inertinite macerals.

Characterization of Pyrolysis Products Obtained from Desmodesmus sp. Cultivated in Anaerobic Digested Effluents (DADE)

2015 ◽  
Vol 11 (6) ◽  
pp. 825-832 ◽  
Author(s):  
Gang Li ◽  
Ren-jie Dong ◽  
Nan Fu ◽  
Yu-guang Zhou ◽  
Dong Li ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Maximum Yield ◽  
Compositional Analysis ◽  
High Yield ◽  
Nitrogen Compounds ◽  
Pyrolysis Products ◽  
Algae Cultivation ◽  
Polycyclic Aromatic ◽  
Lower Temperature

Abstract The present study includes the compositional analysis and pyrolysis products obtained from Desmodesmus sp. cultivated in anaerobic digested effluents (DADE) from 300°C to 800°C. Compared to Desmodesmus sp. cultivated in BG11 (DBG11), both species exhibited a hydrogen content of ca. 6%, ca. 7% of nitrogen, and ca. 0.56% of sulfur except carbon content, of which was lower than DBG11. Pyrolysis products of DADE consisted of aliphatic hydrocarbons, aromatic hydrocarbons, acids, nitrogen compounds, phenols, polycyclic aromatic hydrocarbons (PAHs), alcohols, aldehydes, and furans. Pyrolysis of DADE at 800°C produced 62.52% (the maximum yield) of pyrolysis products compared to 41.89% at 600°C. Considering the reasonably high yield and minimum release of pollutants, lower temperature (600°C) was found to be optimum for producing biofuel from DADE. A process combing anaerobic digestion and algae cultivation can be proposed as a direct and effective way to produce biofuel so as to reduce contaminations to the environment.

scholarly journals Catalytic Fast Pyrolysis of Biomass into Aromatic Hydrocarbons over Mo-Modified ZSM-5 Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1051
Author(s):  
Laizhi Sun ◽  
Zhibin Wang ◽  
Lei Chen ◽  
Shuangxia Yang ◽  
Xinping Xie ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Fast Pyrolysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Catalyst Characterization ◽  
Mass Ratio ◽  
Pyrolysis Gas ◽  
Catalytic Fast Pyrolysis ◽  
Polycyclic Aromatic ◽  
Mo Content ◽  
Pyrolysis Of Biomass

Mo-modified ZSM-5 catalysts were prepared and used to produce aromatic hydrocarbons during catalytic fast pyrolysis (CFP) of biomass. The composition and distribution of aromatics were investigated on pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). The reaction factors, such as the Mo content, the reaction temperature and the catalyst/biomass mass ratio, were also optimized. It was found that the 10Mo/ZSM-5 catalyst displayed the best activity in improving the production of monocyclic aromatic hydrocarbons (MAHs) and decreasing the yield of polycyclic aromatic hydrocarbons (PAHs) at 600 °C and with a catalyst/biomass ratio of 10. Furthermore, according to catalyst characterization and the experiment results, the aromatics formation mechanism over Mo/ZSM-5 catalysts was also summarized and proposed.

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