Thermal decomposition of sewage sludge under N 2 , CO 2 and air: Gas characterization and kinetic analysis

Hernández, Ana Belén Roig; Okonta, Felix; Ntuli, Freeman

doi:10.1016/j.jenvman.2017.03.036

Cited by 38 publications

(30 citation statements)

References 24 publications

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“…Differences observed at higher temperatures most likely result from different sludge compositions used in the two studies. Furthermore, in this study, we observed an inorganic transformation phase (phase 3), which was not reported by Hernandez et al The three sewage samples (P1–P3) of this study were similar as they all exhibited the three distinct combustion phases. However, there are significant differences within the individual combustion phases, especially phase 2.…”

Section: Resultscontrasting

confidence: 63%

“…At the beginning of phase 3, the weight loss remains close to zero and raises again at 650 °C (P1) and 620 °C (P2 and P3). In a comparable TGA study of the combustion of sewage sludge, three combustion phases with slightly different temperature ranges compared to the present study were identified . The first phase in that study describing the evaporation of residual water in the sludge is not displayed in the present study.…”

Section: Resultsmentioning

confidence: 54%

“…Numerous studies have investigated the kinetics of sewage sludge pyrolysis, − referring to incineration in the absence of oxygen. However, the kinetics of sewage sludge combustion (in the presence of oxygen) have only received limited attention. , Hernandez et al investigated the incineration of sewage sludge by differential thermogravimetry (TG) using N 2 , CO 2 , and synthetic air . Five reactions with reaction orders close to one were used to describe the overall devolatilization and combustion of sewage sludge.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Combustion of Sewage Sludge: Kinetics and Speciation of the Combustible

et al. 2018

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Combustion of sewage sludge has become a viable route for sewage sludge management 9 especially as the agricultural use of sewage sludge has become increasingly difficult due to more stringent requirements on the quality of the sewage sludge. Combustion of digested sewage sludge in dedicated 11 mono-combustion facilities is advantageous, as it substantially reduces the volume of the sludge and still 12 allows for a recovery of phosphorus from the sewage sludge ash at a later stage. Despite increasing 13 amounts of sewage sludge being combusted, our knowledge on the respective combustion kinetics is still 14 fragmentary. The goal of this study was, therefore, to identify the major combustion reactions of sewage 15 sludge, assess their Arrhenius parameters (activation energy, pre-exponential factor) and assign suitable 16 reference compounds to the individual reactions. For that purpose, experiments were conducted using a 17 thermogravimetric analyzer (TGA). With matrix inversion, we identified 10 individual reactions. Despite 18 the apparent kinetic compensation most likely caused by insufficient precision of the TGA temperature 19 setting, we were able to relate the major reactions of sewage sludge combustion to the combustion of 20 individual reference compounds. In addition to cellulose and lignin which dominated the weight loss with 21 35% and 20% respectively, hemicellulose, xylan, alginate, and calcite were identified. The dominant 22 fraction of cellulose is consistent with recent studies identifying cellulose mainly originating from toilet 23 paper as a major constituent in wastewater. As the identified model compounds explain more than 80% of 24 the total weight loss observed, our approach allows a rough speciation of the combustible of sewage 25 sludge based on TGA experiments.

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Section: Resultscontrasting

confidence: 63%

Section: Resultsmentioning

confidence: 54%

Section: Introductionmentioning

confidence: 99%

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Combustion of Sewage Sludge: Kinetics and Speciation of the Combustible

et al. 2018

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“…The temperature difference between the surface and core of the particle can be reduced by reducing the heating rate. Several researchers observed similar phenomenon that at lower heating rates, heating of biosolids particles occurs more gradually and leads to a better heat transfer to the inner parts of the biosolids ,, . At higher heating rates, particle heating to the core can be slightly delayed which may delay the overall pyrolysis process.…”

Section: Resultsmentioning

confidence: 99%

“…The values are however different to mechanically‐biologically‐chemically treated biosolids. For example, in a South African study, the activation energy for mechanically‐biologically‐chemically treated biosolids is reported as high as 352 kJ/mol. Similar observation was noted in a Poland study where activation energy for mechanically‐biologically‐chemically treated biosolids is reported as high as 320 kJ/mol.…”

Section: Resultsmentioning

confidence: 99%

A Hybrid Kinetic Analysis of the Biosolids Pyrolysis using Thermogravimetric Analyser

et al. 2018

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In this study, multi‐heating rate and multi‐temperature pyrolysis experiments of mechanically and biologically treated Australian biosolids is conducted in a Thermogravimetric Analyser (TGA). A hybrid approach is applied for the estimation of kinetic parameters of biosolids pyrolysis where model‐free methods such as Kissinger–Akahira–Sunose (KAS) and Ozawa–Flynn–Wall (OFW) are used to derive activation energy while model‐fitting method such as Coats‐Redfern is used to derive pre‐exponential factor. The results obtained from this study are compared with other biosolids, lignocellulosic biomass, microalgae and coal. The activation energy and pre‐exponential factor obtained in the current work are 99.75 kJ/mol and 1.7×109 min−1 respectively. The coefficients of determination (R2) obtained in the determination of activation energies ranged between 0.93 and 0.99.

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Thermal decomposition of antibiotic mycelial fermentation residues in Ar, air, and CO2–N2 atmospheres by TG-FTIR method

Guo

Zheng

et al. 2019

J Therm Anal Calorim

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Thermal decomposition of sewage sludge under N 2 , CO 2 and air: Gas characterization and kinetic analysis

Cited by 38 publications

References 24 publications

Combustion of Sewage Sludge: Kinetics and Speciation of the Combustible

Combustion of Sewage Sludge: Kinetics and Speciation of the Combustible

A Hybrid Kinetic Analysis of the Biosolids Pyrolysis using Thermogravimetric Analyser

Thermal decomposition of antibiotic mycelial fermentation residues in Ar, air, and CO2–N2 atmospheres by TG-FTIR method

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