Kinetic and thermodynamic comparative study of quince bio-waste slow pyrolysis before and after sustainable recovery of pectin compounds

RODRIGO TORRES SCIANCALEPORE; ANABEL FERNANDEZ BRIZUELA; DANIELA A. ASENSIO; MATHIAS RIVEROS ; MARÍA PAULA FABANI; GASTÓN FOUGA; ROSA RODRÍGUEZ; GERMÁN MAZZA

ENERGY CONSERVATION AND MANAGEMENT

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2022 vol. 252 p. 1 - 14

0196-8904

This work aims to study and compare the kinetic and thermodynamic behavior of pyrolysis of quince waste (QW) and pectin-free quince waste (PFQW) after extraction. The pectin extraction with acid treatment had a yield of 3.2 ± 0.1 % (dry basis, db). Pyrolysis was conducted in a macro-TG reactor at three heating rates (5, 10, and 15 °C/min) and temperatures in the range 27-900 °C under a nitrogen atmosphere. A better fit of the experimental data was achieved by modeling the reactions by a multi-step mechanism considering three different parallel reactions for thermal decomposition of hemicelluloses, cellulose, and lignin. The results indicated that the Flynn-Wall-Ozawa (FWO) method provided the best R2, MSE, and AAD values. The resulting values of the thermodynamic activation parameters ΔH, ΔG and ΔS were 53.28 ? 89.36 kJ/mol, 114.54 ? 155.01 kJ/mol, and -0.17 ? (-0.04) kJ/(mol K) for pyrolysis of QW, and 29.97 ? 90.68 kJ/mol, 99.42 ? 158.86 kJ/mol, and -0.23 ? (-0.01) kJ/(mol K) for PFQW. According to bioenergy indicators, PFQW presented good characteristics as a biofuel feedstock due to its high energy density values. The kinetic and thermodynamic parameters indicated greater reactivity of PFQW to pyrolysis compared to QW, showing that in addition to obtaining a product with added value, such as pectin, the extraction process generates a solid residue that is easier to treat under a thermochemical platform. The novelty of the paper focuses on the analysis of sequential processes to valorize quince bio-waste, and on providing valuable kinetic and thermodynamic information.