Experimental studies on the pyrolysis of low rank coal with waste plastics and waxes

Abstract

This work reported the possible conversion of low-grade Indian coal to fuel oil through pyrolysis and co-pyrolysis, to produce an alternate and renewable fuel. It investigated the kinetics and thermodynamics of different grade coals selected from coal mines of Odisha, India by thermogravimetric analysis in temperatures ranging from 30°C to 1000°C under a nitrogen atmosphere at five heating rates of 5, 10, 15, 20, and 25°C minand#8722;1 followed by batch pyrolysis and subsequent analysis of the condensable liquid products. The kinetic parameters were determined using model-fitting approaches, assuming a first-order kinetic model, from 250 635°C (major degradation zone). The calculation of the activation energy (E) and the Arrhenius factor (A) was performed for three distinct grades of coal samples under varying heating rates. Changing the coal grade and heating rate resulted in a considerable variation in the kinetic parameters. The thermodynamic parameters such as entropy change (and#916;S), enthalpy change (and#916;H), and free energy change (and#916;G) were also evaluated using established equations. The batch pyrolysis study of coal was carried out in a semi-batch reactor at different temperatures with an optimum oil yield of 18.94 wt% at 450°C. The chemical composition of pyrolytic oil at different temperatures was investigated by the FTIR and GC-MS analysis confirmed the presence of alcohols and phenols, saturated and unsaturated hydrocarbons, and alicyclic and aromatic hydrocarbons in the coal pyrolytic oil. newlineThe catalytic coal pyrolysis kinetics and thermodynamics of coal with three different types of catalysts (Ceria, Zirconia, and Lanthanum Oxide) was also investigated. The activation energy of pure low-grade coal decreased with the presence of 2.5% Ceria catalyst and increased with a further increase in the amount of catalyst. Compared to thermal pyrolysis, catalytic pyrolysis oil had more phenols, oxygenated compounds, and saturated hydrocarbons and less unsaturated hydrocarbons, aromatics, and cyclic hydrocarbons. newlineThe non-isoth