Kinetics, thermodynamics, and thermal decomposition characteristics of co-pyrolysis of municipality solid waste residue hydrochar and &lt;1.5 g/cm3 fraction of South African discarded fine coal

Uwaoma, R.C.; Schroer, B.J.; Strydom, Christien A.; Bunt, John R.; Matjie, R.H.; Mphahlele, Katlego; Meyer, J.A.

doi:10.1016/j.biteb.2022.100998

Cited by 3 publications

(15 citation statements)

References 38 publications

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“…Non-isothermal conditions were used at a constant heating rate for each experiment. The decomposition rate (d X /d t ) was defined using eq . normald X normald t = f ( X ) k ( T ) where f ( x ) is the conversion function and k ( T ) is the temperature-dependent rate function. , The degree of conversion ( X ) was determined using eq . X = m 0 − m normalT m 0 − m ∞ where m 0 and m ∞ are the initial and final sample mass, respectively. m T represents the mass of a sample at a specific temperature.…”

Section: Methodsmentioning

confidence: 99%

“…m T represents the mass of a sample at a specific temperature. k ( T ) is described by the Arrhenius equation. , k = A .25em nobreak0em0.25em⁢ exp ( − E a R T ) where A (s –1 ), E a (J mol –1 ), and R (J K –1 mol –1 ) are the pre-exponential factor, activation energy, and ideal gas constant, respectively. By substituting the Arrhenius equation into eq and dividing by the heating rate β (β = d T /d t ), eq is obtained …”

Section: Methodsmentioning

confidence: 99%

“…k ( T ) is described by the Arrhenius equation. , k = A .25em nobreak0em0.25em⁢ exp ( − E a R T ) where A (s –1 ), E a (J mol –1 ), and R (J K –1 mol –1 ) are the pre-exponential factor, activation energy, and ideal gas constant, respectively. By substituting the Arrhenius equation into eq and dividing by the heating rate β (β = d T /d t ), eq is obtained normald X normald T = A β .25em nobreak0em0.25em⁢ exp ( − E a R T ) f ( X ) When integrating eq , eq is obtained. g ( X ) = ∫ 0 X normald X f ( X ) = A β ∫ T 0 T exp ( − E a R T ) normald T …”

Section: Methodsmentioning

confidence: 99%

“…By substituting the Arrhenius equation into eq and dividing by the heating rate β (β = d T /d t ), eq is obtained normald X normald T = A β .25em nobreak0em0.25em⁢ exp ( − E a R T ) f ( X ) When integrating eq , eq is obtained. g ( X ) = ∫ 0 X normald X f ( X ) = A β ∫ T 0 T exp ( − E a R T ) normald T where T = T 0 + β t and T 0 is the initial experimental temperature …”

Section: Methodsmentioning

confidence: 99%

“…It is difficult to obtain the mechanism for each reaction; therefore, iso-conversional methods are used to estimate these parameters . Multiple iso-conversional methods have been used to determine kinetic parameters for both coal and plastics; , however, the use of these methods have not been reported on the pyrolysis of mixtures of coal and plastics.…”

Section: Introductionmentioning

confidence: 99%

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Mechanical and Thermal Properties of Extrudates Produced from Discarded Coal Fines and Recycled Plastics as Binders

et al. 2023

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This study focuses on the extrusion of discarded coal fines from the Highveld coalfield together with recycled lowdensity polyethylene (LDPE) and polypropylene (PP) which are used as binders to produce agglomerates with better handling properties than the coal fines for industrial use. The binder content varied between 5 and 100 wt %. The barrels of the twin screw extruder were kept at a temperature of 220 °C to melt the binders while forcing the mixture through a 10 mm die. The extrudates containing 10% or more binder were strong and homogeneous, while a 5% binder addition proved to be too low to produce homogeneous extrudates. The extrudates containing 10% LDPE and 10% PP showed compressive strengths of 17.5 and 7.9 MPa before breaking, respectively. The rest of the extrudates (>10% plastic addition) did not break but merely flattened as the plastic load increased. The compressive strength of all the extrudates showed no significant difference after being exposed to water. Furthermore, the extrudates absorbed less than 5% water after being submerged for 24 h. Thermogravimetric analysis of the extrudates was conducted under a nitrogen atmosphere up to 900 °C. Three iso-conversional methods, Kissinger−Akahira−Sunose, Starink, and Flynn−Wall−Ozawa, were used to determine the activation energy of the extrudates and raw materials. The lower activation energy and conversion temperatures found for the extrudates indicate a synergy between plastic and coal fines when the extrudates are pyrolyzed. Results from this study suggest that the coextrusion of recycled plastic with coal fines will produce solid carbonaceous fuels with high hydrophobicity, heating value, and high mechanical strength compared to coal fines.

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