Assessing the bioenergy potential of high-ash anaerobic sewage sludge using pyrolysis kinetics and thermodynamics to des

  • PDF / 1,361,946 Bytes
  • 12 Pages / 595.276 x 790.866 pts Page_size
  • 55 Downloads / 177 Views

DOWNLOAD

REPORT


ORIGINAL ARTICLE

Assessing the bioenergy potential of high-ash anaerobic sewage sludge using pyrolysis kinetics and thermodynamics to design a sustainable integrated biorefinery José Luiz Francisco Alves 1 & Jean Constantino Gomes da Silva 1 & Mariana Pires Languer 1 & Luciane Batistella 2 & Michele Di Domenico 3 & Valdemar Francisco da Silva Filho 1 & Regina de Fátima Peralta Muniz Moreira 1 & Humberto Jorge José 1 Received: 11 July 2020 / Revised: 10 September 2020 / Accepted: 16 September 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020

Abstract A new opportunity for producing valuable biorefinery products can be found by integrating biochemical and thermochemical processing with municipal wastewater treatment. This study is the first to evaluate the kinetic triplet and thermodynamic parameters from the pyrolysis of typical Brazilian anaerobic sewage sludge performed in the framework of a multi-step solidstate process. The physicochemical characteristics of the anaerobic sewage sludge are comparable to those obtained from lowrank coals. The pyrolysis characteristics were analyzed by non-isothermal thermogravimetry under different heating rates (10, 25, 50, and 90 K min−1) in an inert atmosphere. Two devolatilization stages were distinguished from the active pyrolysis zone, with an average mass loss of 47.56 wt% (sum) in the range of 398–953 K. For each devolatilization stage, three isoconversional methods (Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, and Starink) were utilized to calculate the activation energy, and then the compensation effect method was applied to find the pre-exponential factor. The average activation energies calculated ranged from 113.7 to 117.3 kJ mol−1 for the first stage and from 115.7 to 121.9 kJ mol−1 for the second stage, with respective preexponential factors of 7.39 × 109 min−1 and 8.80 × 107 min−1. According to the master-plots method, it was found that the first stage followed the fourth-order (F4) model, while the second stage was described by the second-order (F2) model. Based on the statistical evaluation, the devolatilization behaviors reconstructed from overall kinetic expression agree reasonably well with the experimental data, proving its practical importance for designing a pyrolytic processing system using anaerobic sewage sludge as raw material. This study contributes by providing useful insights that can be applied to a large-scale biorefinery as a critical step towards producing biofuels coupled to municipal wastewater treatment in an environmentally sustainable manner.

José Luiz Francisco Alves and Constantino Gomes da Silva contributed equally to this work and shared senior authorship. Highlights A new option for useful biorefinery products from municipal wastewater treatment High-ash anaerobic sewage sludge is an underutilized feedstock for pyrolysis Bioenergy potential of high-ash anaerobic sewage sludge via pyrolysis was evaluated New data for optimizing a pyrolysis process in an integrated biorefinery approach The pyrolysis can be combined with