Full text

Turn on search term navigation

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.

Abstract

Featured Application

This manuscript studies the feasibility of combining anaerobic digestion with high temperature and pressure treatments to reduce the final amount of digestate requiring disposal and to produce a material with higher added value. However, thermal treatments present high energy demand and installation costs. This research is a preliminary study performed to evaluate different process configurations and establish strategies for reducing the thermal demand of the combined approach.

Abstract

Anaerobic digestion is a biological process with wide application for the treatment of high organic-containing streams. The production of biogas and the lack of oxygen requirements are the main energetic advantages of this process. However, the digested stream may not readily find a final disposal outlet under certain circumstances. The present manuscript analyzed the feasibility of valorizing digestate by the hydrothermal carbonization (HTC) process. A hypothetical plant treating cattle manure and cheese whey as co-substrate (25% v/w, wet weight) was studied. The global performance was evaluated using available data reported in the literature. The best configuration was digestion as a first stage with the subsequent treatment of digestate in an HTC unit. The treatment of manure as sole substrate reported a value of 752 m3/d of biogas which could be increased to 1076 m3/d (43% increase) when coupling an HTC unit for digestate post-treatment and the introduction of the co-substrate. However, the high energy demand of the combined configurations indicated, as the best alternative, the valorization of just a fraction (15%) of digestate to provide the benefits of enhancing biogas production. This configuration presented a much better energy performance than the thermal hydrolysis pre-treatment of manure. The increase in biogas production does not compensate for the high energy demand of the pre-treatment unit. However, several technical factors still need further research to make this alternative a reality, as it is the handling and pumping of high solid slurries that significantly affects the energy demand of the thermal treatment units and the possible toxicity of hydrochar when used in a biological process.

Details

Title
Feasibility of Coupling Anaerobic Digestion and Hydrothermal Carbonization: Analyzing Thermal Demand
Author
González, Rubén 1   VIAFID ORCID Logo  ; Ellacuriaga, Marcos 2 ; Aguilar-Pesantes, Alby 2 ; Carrillo-Peña, Daniela 3   VIAFID ORCID Logo  ; García-Cascallana, José 2 ; Smith, Richard 4 ; Gómez, Xiomar 3 

 Department of Electrical, Systems and Automatic Engineering, School of Electrical, Industrial and Informatics, University of León, Campus de Vegazana, 24071 León, Spain; [email protected] 
 Department of Applied Chemistry and Physics, School of Industrial Engineering, University of León, Campus de Vegazana, 24071 León, Spain; [email protected] (M.E.); [email protected] (A.A.-P.); [email protected] (J.G.-C.) 
 Chemical and Environmental Bioprocess Engineering Group, Natural Resources Institute (IRENA), University of León, Av. de Portugal 41, 24071 León, Spain; [email protected] 
 Department of Chemical and Environmental Engineering, University of Nottingham, Coates Building B12, Nottingham NG7 2RD, UK; [email protected] 
First page
11660
Publication year
2021
Publication date
2021
Publisher
MDPI AG
e-ISSN
20763417
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2612744421
Copyright
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.