Title: | Fundamental mechanisms and reactions in non-catalytic subcritical hydrothermal processes: A review |
Author(s): | Yousefifar A; Baroutian S; Farid MM; Gapes DJ; Young BR; |
Address: | "Department of Chemical and Materials Engineering, Faculty of Engineering, The University of Auckland, Auckland, New Zealand. Department of Chemical and Materials Engineering, Faculty of Engineering, The University of Auckland, Auckland, New Zealand. Electronic address: s.baroutian@auckland.ac.nz. Department of Chemical and Materials Engineering, Faculty of Engineering, The University of Auckland, Auckland, New Zealand. Electronic address: m.farid@auckland.ac.nz. Scion, Te Papa Tipu Innovation Park, Rotorua, New Zealand" |
DOI: | 10.1016/j.watres.2017.06.069 |
ISSN/ISBN: | 1879-2448 (Electronic) 0043-1354 (Linking) |
Abstract: | "The management and disposal of solid waste is of increasing concern across the globe. Hydrothermal processing of sludge has been suggested as a promising solution to deal with the considerable amounts of sludge produced worldwide. Such a process not only degrades organic compounds and reduces waste volume, but also provides an opportunity to recover valuable substances. Hydrothermal processing comprises two main sub-processes: wet oxidation (WO) and thermal hydrolysis (TH), in which the formation of various free radicals results in the production of different intermediates. Volatile fatty acids (VFAs), especially acetic acid, are usually the main intermediates which remain as a by-product of the process. This paper aims to review the fundamental mechanism for hydrothermal processing of sludge, and the formation of different free radicals and intermediates therein. In addition, the proposed kinetic models for the two processes (WO and TH) from the literature are reviewed and the advantages and disadvantages of each model are outlined. The effect of mass transfer as a critical component of the design and development of the processes, which has been neglected in most of these proposed models, is also reviewed, and the effect of influencing parameters on the processes' controlling step (reaction or mass transfer) is discussed" |
Keywords: | "*Fatty Acids, Volatile Hydrolysis Oxidation-Reduction Sewage *Waste Disposal, Fluid Free radicals Hydrothermal processing Kinetics Mass transfer Thermal hydrolysis Wet oxidation;" |
Notes: | "MedlineYousefifar, Azadeh Baroutian, Saeid Farid, Mohammed M Gapes, Daniel J Young, Brent R eng Review England 2017/07/15 Water Res. 2017 Oct 15; 123:607-622. doi: 10.1016/j.watres.2017.06.069. Epub 2017 Jun 30" |