Study on Nitrogen Transformation during Sewage Sludge Pyrolysis at Low Temperatures

2015 ◽  
Vol 768 ◽  
pp. 484-495 ◽  
Author(s):  
Si Jiang Xiong ◽  
Ren Zhong Pang ◽  
Jian Kun Zhuo ◽  
Qiang Yao
Keyword(s):  
Sewage Sludge ◽  
Low Temperatures ◽  
Relative Proportion ◽  
Nitrogen Transformation ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Spectrometry ◽  
Pyrolysis Gas ◽  
Thermogravimetric Analyzer ◽  
Nitrogen Conversion ◽  
Amine Compounds

The nitrogen conversion with attention to the intermediates and NOx precursors has been investigated during the primary pyrolysis of sewage sludge by using Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetric analyzer (TGA) coupled with Fourier transform infrared spectrometry (FTIR). The results indicated that 75.4% of total nitrogen exists in the forms of protein in the sewage sludge. Amine compounds and nitrogen heterocyclics were found to be the main nitrogenated intermediates during the pyrolysis process in the temperature range of 250-400 °C. As the dominant nitrogenated compounds, the relative proportions of amine compounds were above 52% in all cases. And since the decomposition of sewage sludge was promoted by high temperature, the relative proportion of amine compounds increased by 24.6% when the temperature raised from 300 to 400 °C. Moreover, the generation of NH3 at 250 oC was mainly derived from the decomposition of ammonium salt, while the deamination of amine compounds led to a significant increase of NH3 at 300 °C.

Application of a fractionation technique for better understanding of the removal of natural organic matter by alum coagulation

2002 ◽  
Vol 2 (5-6) ◽  
pp. 427-433 ◽  
Author(s):  
J. van Leeuwen ◽  
C. Chow ◽  
R. Fabris ◽  
N. Withers ◽  
D. Page ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
High Performance ◽  
Relative Proportion ◽  
Water Source ◽  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Alum Treatment ◽  
Hydrophobic Acids

To gain an improved understanding of the types of organic compounds that are recalcitrant to water treatment, natural organic matter (NOM) isolates from two drinking water sources (Mt. Zero and Moorabool reservoirs, Victoria, Australia) were separated into fractions of distinct chemical behaviour using resins. Four fractions were obtained from each water source and were organics absorbed to: (1) XAD-8 (very hydrophobic acids, VHA); (2) DAX-4 (slightly hydrophobic acids, SHA); (3) bound to an anion exchange resin (charged organics, CHAR); and (4) not absorbed or bound to resins (neutrals, NEUT). These fractions were then tested to determine the capacity of alum to remove them from water and to correlate this with the character of each isolate. The fractions were characterised by the application of high performance size exclusion chromatography (HPSEC), bacterial regrowth potential (BRP), trihalomethane formation potential (THMFP), pyrolysis gas-chromatography mass spectrometry (Py-GC-MS) and thermochemolysis. The highest removals of dissolved organic carbon (DOC) by alum treatment were in waters spiked with the CHAR fractions while the NEUT fractions were the most recalcitrant. The number average molecular weights (Mn) of DOC of the CHAR fractions before treatment were the highest, whilst those of the NEUT fractions were the lowest. After alum treatment, the Mn of the NEUT fractions were only slightly reduced. Results from Py-GC-MS and thermochemolysis indicate that the NEUT fractions had the highest relative proportion of saccharide derived organic material. Nonetheless, the BRP of waters spiked with the NEUT fractions differed markedly, indicating that organics recalcitrant to alum treatment can vary substantially in their chemical composition and capacity to support microbial growth.

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.

Novel flame retardancy effect of phenethyl-bridged DOPO derivative on epoxy resin

2017 ◽  
Vol 30 (6) ◽  
pp. 667-676 ◽  
Author(s):  
Wei Yan ◽  
Jie Yu ◽  
Mingqiu Zhang ◽  
Lijuan Long ◽  
Tao Wang ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Visual Observation ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Spectrometry ◽  
Pyrolysis Gas ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Potential Applications ◽  
Flame Retardant Properties ◽  
Oxide Derivative

A series of flame-retardant epoxy resins (EPs) containing either phenethyl-bridged 9 or 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative (bisDOPO) were prepared. The flame-retardant properties of bisDOPO on EP composites were characterized by the limiting oxygen index (LOI), the UL-94 vertical burning, and the cone calorimeter test (CCT).The LOI of the EP/bisDOPO composites increased from 21.8% to 38.0%, and the hybrids with the 10 wt% bisDOPO obtained a V-0 rating in the UL94 vertical burning test. The char residue following the CCT showed intumescent structures with continuous and compact surfaces that can effectively suppress the spread of the flame and extinguish the fire. This was confirmed through both visual observation and scanning electron microscopy (SEM) measurements. The flame-retardant mechanism was studied by Fourier transform infrared spectroscope (FTIR), thermogravimetric analysis/infrared spectrometry, SEM/energy-dispersive X-ray, and pyrolysis-gas chromatography/mass spectrometry. Overall, bisDOPO was an effective flame retardant with potential applications within EP.

scholarly journals Torrefaction of Short Rotation Coppice of Poplar under Oxidative and Non-Oxidative Atmospheres

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1479 ◽  
Author(s):  
Ana Álvarez ◽  
Gemma Gutiérrez ◽  
María Matos ◽  
Consuelo Pizarro ◽  
Julio L. Bueno
Keyword(s):  
Kinetic Constant ◽  
Short Rotation Coppice ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Decomposition Products ◽  
Value Analysis ◽  
Heating Value ◽  
Thermogravimetric Analyzer ◽  
Short Rotation ◽  
Reaction Orders

Torrefaction improves some of the poorest characteristics of biomass such as hygroscopicity, low energy density, or poor grindability which may cause some problems during its handling, storage and combustion. The aim of this work is to apply the torrefaction process to a Short Rotation Coppice of Poplar (SRCP) and characterize the new fuel. Therefore, both non-oxidative and oxidative torrefaction of SRCP were conducted in a tube furnace reactor within the range 200–240 °C and the torrefied biomass was fully characterize, i.e., proximate, ultimate, compositional and heating value analysis as well as wettability studies. In addition, Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) was performed at optimal torrefaction temperature. Torrefaction kinetics were obtained using a thermogravimetric analyzer at optimal torrefaction temperature. Minimum mass and energy yields were found to be respectively 85.0% and 87.4% for oxidative torrefaction and 87.5% and 94.1% for non-oxidative option. Moisture was reduced from 6.97% to 4.8% and 4.4% for oxidative and non-oxidative torrefaction, respectively. Wettability studies carried out show an increase in hydrophobic behavior. Lignin was affected by torrefaction since decomposition products from guaiacyl (G) and syringyl (S) units were released during Py-GC/MS experiments. The reaction orders were 1.92 and 1.82 for oxidative and non-oxidative torrefaction, respectively and kinetic constant values were 5.99·× 10−5 and 2.98·× 10−5 s−1.

Thermo-Oxidative Decomposition of Lovage (Levisticum officinale) and Davana (Artemisia pallens) Essential Oils under Simulated Tobacco Heating Product Conditions

2020 ◽  
Vol 29 (1) ◽  
pp. 27-43
Author(s):  
Emma Jakab ◽  
Zoltán Sebestyén ◽  
Bence Babinszki ◽  
Eszter Barta-Rajnai ◽  
Zsuzsanna Czégény ◽  
...  
Keyword(s):  
Low Temperature ◽  
Essential Oils ◽  
Relative Yield ◽  
Gas Chromatography Mass Spectrometry ◽  
Intramolecular Rearrangement ◽  
Oxidation Reactions ◽  
Pyrolysis Gas ◽  
Oxidative Decomposition ◽  
Oxidative Pyrolysis ◽  
Artemisia Pallens

SummaryThe thermo-oxidative decomposition of lovage (Levisticum officinale) and davana (Artemisia pallens) essential oils has been studied by pyrolysis-gas chromatography/mass spectrometry in 9% oxygen and 91% nitrogen atmosphere at 300 °C to simulate low-temperature tobacco heating conditions. Both lovage and davana oils contain numerous chemical substances; the main components of both oils are various oxygen-containing compounds. Isobenzofuranones are the most important constituents of lovage oil, and their relative intensity changed significantly during oxidative pyrolysis. (Z)-ligustilide underwent two kinds of decomposition reactions: an aromatization reaction resulting in the formation of butylidenephthalide and the scission of the lactone ring with the elimination of carbon dioxide or carbon monoxide. Davanone is the main component of davana oil, which did not decompose considerably during low-temperature oxidative pyrolysis. However, the relative yield of the second most intensive component, bicyclogermacrene, reduced markedly due to bond rearrangement reactions. Davana ether underwent oxidation reactions leading to the formation of various furanic compounds. The changes in the composition of both essential oils could be interpreted in terms of bond splitting, intramolecular rearrangement mechanisms and oxidation reactions of several constituents during low-temperature oxidative pyrolysis. The applied thermo-oxidative method was found to be suitable to study the stability of the essential oils and monitor the decomposition products under simulated tobacco heating conditions. In spite of the complicated composition of the essential oils, no evidence for interaction between the oil components was found. [Beitr. Tabakforsch. Int. 29 (2020) 27–43]

CHARACTERISATION OF DISSOLVED ORGANIC CARBON (DOC) LEACHED FROM LEAVES IN WATER

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Markus Heryanto Langsa
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Total Organic Carbon ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Pyrolysis Gas Chromatography ◽  
Chromatography Mass Spectrometry ◽  
Pinus Radiate

<p>Penelitian ini bertujuan untuk menentukan senyawa organik khususnya organic karbon terlarut (DOC) dari dua spesies daun tumbuhan (<em>wandoo eucalyptus </em>and <em>pinus radiate, conifer</em>) yang larut dalam air selama periode 5 bulan leaching eksperimen. Kecepatan melarutnya senyawa organic ditentukan secara kuantitatif dan kualitatif menggunakan kombinasi dari beberapa teknik diantaranya Total Organic Carbon (TOC) analyser, Ultraviolet-Visible (UV-VIS) spektrokopi dan pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS).</p><p>Hasil analisis DOC dan UV menunjukkan peningkatan yang tajam dari kelarutan senyawa organic di awal periode pengamatan yang selanjutnya berkurang seiring dengan waktu secara eksponensial. Jumlah relatif senyawa organic yang terlarut tergantung pada luas permukaan, aktifitas mikrobiologi dan jenis sampel tumbuhan (segar atau kering) yang digunakan. Fluktuasi profil DOC dan UV<sub>254</sub> disebabkan oleh aktifitas mikrobiologi. Diperoleh bahwa daun kering lebih mudah terdegradasi menghasilkan senyawa organic dalam air dibandingkan dengan daun segar. Hasil pyrolysis secara umum menunjukkan bahwa senyawa hidrokarbon aromatic dan fenol (dan turunannya) lebih banyak ditemukan pada residue sampel setelah proses leaching kemungkinan karena adanya senyawa lignin atau aktifitas humifikasi mikrobiologi membuktikan bahwa senyawa-senyawa tersebut merupakan komponen penting dalam proses karakterisasi DOC.</p>

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