Thermal processing of sewage sludge by drying, pyrolysis, gasification and combustion

2001 ◽  
Vol 44 (10) ◽  
pp. 333-339 ◽  
Author(s):  
P. Stolarek ◽  
S. Ledakowicz
Keyword(s):  
Thermal Decomposition ◽  
Sewage Sludge ◽  
Kinetic Parameters ◽  
Thermal Processing ◽  
Combustion Process ◽  
Order Kinetic ◽  
Municipal Sludge ◽  
Pyrolysis Kinetics ◽  
Exponential Factor ◽  
First Order

Thermal processing of sewage sludge including drying, pyrolysis and gasification or combustion may be an alternative to other ways of utilising it. In this paper thermogravimetric analysis (TGA) was employed in the investigation of thermal decomposition of sewage sludge. The kinetic parameters of drying, pyrolysis and gasification or combustion of sewage sludge have been determined in an inert-gas (argon) and additionally some series of the sludge decomposition experiments have been carried out in air, in order to compare pyrolysis and combustion. The pyrolysis char has been gasified with carbon dioxide. A typical approach to the kinetics of thermal decomposition of a solid waste is to divide the volatile evolution into a few fractions (lumps), each of which is represented by a single first-order reaction. If these lumps are assumed to be non-interacting and evolved by independent parallel reactions the first-order kinetic parameters such as activation energy Ei and pre-exponential factor Ai can be determined from mathematical evaluation of TG or DTG curves. The object of our investigations was a municipal sludge from the two wastewater treatment plants (WTP) in Poland. The experiments have been carried out in the thermobalance Mettler-Toledo type TGA/SDTA851 LF, in the temperature range 30-1,000°C. Five different values of heating rate have been applied β = 2, 5, 10, 15 and 20 K/min. The values of Ei and Ai have been determined for all recognised lumps of gaseous products. The method employed has also revealed its usefulness for the determination of kinetic parameters for municipal sludge, that possess an undefined content. An alternative route to combustion of sewage sludge is its gasification, which significantly increases the gaseous product (pyrolytic gas + syngas). Besides pyrolysis kinetics, gasification or combustion process kinetics have also been determined.

scholarly journals Influence of Liming on Kinetics of Sewage Sludge Pyrolysis

2019 ◽  
Vol 26 (1) ◽  
pp. 175-188
Author(s):  
Paweł Stolarek ◽  
Stanisław Ledakowicz ◽  
Radosław Ślęzak
Keyword(s):  
Thermal Decomposition ◽  
Sewage Sludge ◽  
Mass Loss ◽  
Kinetic Parameters ◽  
Heating Rate ◽  
Visual Analysis ◽  
Pyrolysis Kinetics ◽  
Exponential Factor ◽  
The Impact ◽  
Kinetics Of

Abstract Thermogravimetry (TG) is the fast and reliable method for characterization of thermal decomposition of any material and in particular to determine the kinetics of pyrolytic decomposition of sewage sludge. Two types of sewage sludge with and without addition of lime were investigated from kinetic point of view. For TG analysis samples of selected sewage sludge were heated under the inert atmosphere of argon with constant heating rate from 303 to 1273 K; the three heating rate β = 5, 10 and 20 K/min were chosen. The iso-conversion methods of Friedman and Ozawa-Flynn-Wall were employed for analysis of TG results. As the sewage sludge decomposition is very complex process it cannot be described by a simple stoichiometric equation, therefore the so called lumping of reactions in the selected temperature ranges were used with detailed principles arising from visual analysis of DTG curve. The deconvolution of DTG curves performed according to Fraser-Suzuki asymmetric profile allowed the identification of number of lumps and their contribution to the overall mass loss. So the decomposition of sewage sludge with lime addition could be described with five groups of reactions while the one without lime by means of six lumps. The thermal decomposition of sewage sludge was assumed to proceed according to the scheme of parallel concurrent independent reactions of n-th order. The values of the apparent activation energies at different constant values of conversion degrees were determined by the iso-conversion analysis. To estimate the kinetic parameters the non-linear regression with Levenberg-Marquart optimization procedure was used. The kinetic parameters such as activation energy, pre-exponential factor, reaction order and fraction of total mass loss associated with a given reaction were determined. The impact of sewage sludge liming revealed in essential differences of pyrolysis products and pyrolysis kinetics of limed sludge and without lime one was highlighted.

Kinetics of bioactive compounds in functional spice Jiangpo during thermal processing

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Xiaoyan Dai ◽  
Chenhuan Yu ◽  
Qiaofeng Wu
Keyword(s):  
Kinetic Parameters ◽  
Bioactive Compounds ◽  
Thermal Processing ◽  
Order Rate Constant ◽  
Heat Processing ◽  
Order Kinetic ◽  
Time Intervals ◽  
First Order ◽  
Order Kinetic Model ◽  
Kinetics Of

Abstract Jiangpo is an increasingly popular East Asian spice which is made from Mangnolia officinalis bark and ginger juice. Since it induces bioactive compounds decomposition and has influence on final flavor and fragrance, cooking is regarded as the key operation in preparation of Jiangpo. To evaluate the bioactive compounds content changes of Jiangpo during thermal processing, kinetic parameters including reaction order, rate constant, T1/2 and activation energy of bioactive markers namely honokiol, magnolol and curcumin were determined. Cooking was set at temperatures 60, 90 and 120 °C for selected time intervals. Results displayed the thermal kinetic characteristics of the three compounds. Thermal degradation of Honokiol and magnolol both followed first order kinetic model and the loss of curcumin fitted second order. A mathematical model based on the obtained kinetic parameters has also been developed to predict the degradation of honokiol, magnolol and curcumin in non-isothermal state. All the information in this paper could contribute necessary information for optimizing the existing heat processing of Jiangpo.

scholarly journals Kinetics of the thermal decomposition of pine needles

2015 ◽  
Vol 7 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Alok Dhaundiyal ◽  
Jitendra Gangwar
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Pine Needles ◽  
Experimental Results ◽  
Pyrolysis Process ◽  
Order Model ◽  
Exponential Factor ◽  
First Order ◽  
Model Free ◽  
Good Agreement

Abstract A kinetic study of the pyrolysis process of pine needles was examined using a thermogravimetric analyser. The weight loss was measured in nitrogen atmosphere at a purge flow rate of 100 ml/min. The samples were heated over a range of temperature of 19°C–600°C with a heating rate of 10°C/min. The results obtained from the thermal decomposition process indicate that there are three main stages: dehydration, active and passive pyrolysis. The kinetic parameters for the different samples, such as activation energy and pre-exponential factor, are obtained by the shrinking core model (reaction-controlled regime), the model-free, and the first-order model. Experimental results showed that the shrinking model is in good agreement and can be successfully used to understand degradation mechanism of loose biomass. The result obtained from the reaction-controlled regime represented actual values of kinetic parameters which are the same for the whole pyrolysis process; whereas the model-free method presented apparent values of kinetic parameters, as they are dependent on the unknown function ϕ(C), on the sum of the parameters of the physical processes, and on the chemical reactions that happen simultaneously during pyrolysis. Experimental results showed that values of kinetic constant from the first-order model and the SCM are in good agreement and can be successfully used to understand the behaviour of loose biomass (pine needles) in the presence of inert atmosphere. Using TGA results, the simulating pyrolysis can be done, with the help of computer software, to achieve a comprehensive detail of the devolatilization process of different types of biomasses.

scholarly journals Isothermal Kinetic Analysis of the Thermal Decomposition of Wood Chips from an Apple Tree

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 195
Author(s):  
Ivan Vitázek ◽  
Martin Šotnar ◽  
Stella Hrehová ◽  
Kristína Darnadyová ◽  
Jan Mareček
Keyword(s):  
Thermal Decomposition ◽  
Apple Tree ◽  
Combustion Process ◽  
Reaction Model ◽  
Wood Chips ◽  
Small Scale ◽  
Exponential Factor ◽  
Air Atmosphere ◽  
First Order Chemical Reaction ◽  
Isothermal Kinetic

The thermal decomposition of wood chips from an apple tree is studied in a static air atmosphere under isothermal conditions. Based on the thermogravimetric analysis, the values of the apparent activation energy and pre-exponential factor are 34 ± 3 kJ mol−1 and 391 ± 2 min−1, respectively. These results have also shown that this process can be described by the rate of the first-order chemical reaction. This reaction model is valid only for a temperature range of 250–290 °C, mainly due to the lignin decomposition. The obtained results are used for kinetic prediction, which is compared with the measurement. The results show that the reaction is slower at higher values of degree of conversion, which is caused by the influence of the experimental condition. Nevertheless, the obtained kinetic parameters could be used for the optimization of the combustion process of wood chips in small-scale biomass boilers.

Consecutive reactions in the thermal decomposition of phenylalkyldiazirines

1977 ◽  
Vol 55 (20) ◽  
pp. 3596-3601 ◽  
Author(s):  
Michael T. H. Liu ◽  
Barry M. Jennings
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Diazo Compounds ◽  
First Order ◽  
Temperature Range ◽  
Decomposition Reactions ◽  
Consecutive Reactions ◽  
Rate Processes ◽  
Subsequent Decomposition

The thermal decomposition of phenyl-n-butyldiazirine and of phenylmethyldiazirine in DMSO and in HOAc have been investigated over the temperature range 80–130 °C. The intermediate diazo compounds, 1-phenyl-1-diazopentane and 1-phenyldiazoethane respectively have been detected and isolated. The decomposition of phenyl-n-butyldiazirine and the subsequent decomposition of its product, 1-phenyl-1-diazopentane, are an illustration of consecutive reactions. The kinetic parameters for the isomerization and decomposition reactions have been determined. The isomerization of phenylmethyldiazirine to 1-phenyldiazoethane is first order and probably unimolecular but the kinetics for the subsequent reactions of 1-phenyldiazoethane are complicated by several competing rate processes.

Co-pyrolysis kinetics of sewage sludge and oil shale thermal decomposition using TGA–FTIR analysis

2016 ◽  
Vol 118 ◽  
pp. 345-352 ◽  
Author(s):  
Yan Lin ◽  
Yanfen Liao ◽  
Zhaosheng Yu ◽  
Shiwen Fang ◽  
Yousheng Lin ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Sewage Sludge ◽  
Oil Shale ◽  
Ftir Analysis ◽  
Pyrolysis Kinetics ◽  
Kinetics Of

Inhibition kinetics and mechanism of glutathione and quercetin on acrylamide in the low-moisture Maillard systems

2020 ◽  
Author(s):  
Xiping Nan ◽  
Shuli Nan ◽  
Xianpeng Zeng ◽  
Lining Kang ◽  
Xiangying Liu ◽  
...  
Keyword(s):  
Thermal Processing ◽  
Theoretical Data ◽  
Order Kinetic ◽  
Inhibition Kinetics ◽  
Competitive Reaction ◽  
Binding Reaction ◽  
Inhibition Effect ◽  
First Order ◽  
Maximum Inhibition ◽  
Kinetics Of

The inhibition kinetics of glutathione (GSH) and quercetin on Acrylamide (AA) formation in the low-moisture Maillard systems were investigated at 180 °C. The inhibition rates in an equal-molar asparagine/glucose (Asn/Glc) system was higher than those in asparagine/fructose (Asn/Fru) system, and the maximum inhibition rates for AA were 57.75% with GSH of 10 -2 mol L -1 and 51.38% with quercetin of 10 -1 mol L -1 . The Logistic-Index dynamic model and simplified two consecutive first-order kinetic models were well fitted to the changes of AA in the Asn/Glc system. The kinetics results suggested the predominant inhibition effect of GSH on AA could be attributed to the competitive reaction between GSH and Asn for the consumption of Glc. The kinetic results and HPLC-MS/MS analysis of quercetin inhibiting AA indicated that quercetin might mitigate AA through the binding reaction of quercetin decomposition product and Maillard intermediate product. These experimental results can provide theoretical data to control the formation of AA during food thermal processing.

Kinetic Investigation of Thermal Decomposition Reactions of Podophyllic Acid and Picropodophyllic Acid

2011 ◽  
Vol 391-392 ◽  
pp. 1230-1234
Author(s):  
Pu Hong Wen
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Model ◽  
Kinetic Parameters ◽  
Decomposition Reaction ◽  
Exponential Factor ◽  
Decomposition Reactions ◽  
Integral Forms ◽  
Free Energy Of Activation ◽  
Entropy Of Activation ◽  
Temperature Programmed

The thermal behavior and thermal decomposition kinetic parameters of podophyllic acid and picropodophyllic acid in a temperature-programmed mode have been investigated by means of DSC and TG-DTG. The kinetic model functions in differential and integral forms of the thermal decomposition reactions mentioned above for leading stage were established. The kinetic parameters of the apparent activation energy Ea and per-exponential factor A were obtained from analysis of the TG-DTG curves by integral and differential methods. The most probable kinetic model function of the decomposition reaction in differential form was 2/3•α-1/2 for podophyllic acid and 1/2• (1-α)-1 for picropodophyllic acid. The values of Ea indicated that the reactivity of picropodophyllic acid was highter than that of podophyllic acid in the thermal decomposition reaction. The values of the entropy of activation ΔS≠, enthalpy of activation ΔH≠ and free energy of activation ΔG≠ of the reactions were estimated.

scholarly journals Modeling of Metalized Food Packaging Plastics Pyrolysis Kinetics Using an Independent Parallel Reactions Kinetic Model

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1763 ◽  
Author(s):  
Samy Yousef ◽  
Justas Eimontas ◽  
Nerijus Striūgas ◽  
Mohammed Ali Abdelnaby
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Food Packaging ◽  
Decomposition Temperature ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Average Deviation ◽  
Exponential Factor ◽  
Parallel Reactions

Recently, a pyrolysis process has been adapted as an emerging technology to convert metalized food packaging plastics waste (MFPWs) into energy products with a high economic benefit. In order to upscale this technology, the knowledge of the pyrolysis kinetic of MFPWs is needed and studying these parameters using free methods is not sufficient to describe the last stages of pyrolysis. For a better understanding of MFPWs pyrolysis kinetics, independent parallel reactions (IPR) kinetic model and its modification model (MIPR) were used in the present research to describe the kinetic parameters of MFPWs pyrolysis at different heating rates (5–30 °C min−1). The IPR and MIPR models were built according to thermogravimetric (TG)-Fourier-transform infrared spectroscopy (FTIR)-gas chromatography−mass spectrometry (GC-MS) results of three different types of MFPWs (coffee, chips, and chocolate) and their mixture. The accuracy of the developed kinetic models was evaluated by comparing the conformity of the DTG experimental results to the data calculated using IPR and MIPR models. The results showed that the dependence of the pre-exponential factor on the heating rate (as in the case of MIPR model) led to better conformity results with high predictability of kinetic parameters with an average deviation of 2.35% (with an improvement of 73%, when compared to the IPR model). Additionally, the values of activation energy and pre-exponential factor were calculated using the MIPR model and estimated at 294 kJ mol−1 and 5.77 × 1017 kJ mol−1 (for the mixed MFPW sample), respectively. Finally, GC-MS results illustrated that pentane (13.8%) and 2,4-dimethyl-1-heptene isopropylcyclobutane (44.31%) represent the main compounds in the released volatile products at the maximum decomposition temperature.

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