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Molecules 2018, 23(8), 2006;

Comparison of Different Electricity-Based Thermal Pretreatment Methods for Enhanced Bioenergy Production from Municipal Sludge

UBC Bioreactor Technology Group, School of Engineering, The University of British Columbia Okanagan Campus, 1137 Alumni Avenue, Kelowna, BC V1V 1V7, Canada
Author to whom correspondence should be addressed.
Received: 30 June 2018 / Revised: 24 July 2018 / Accepted: 9 August 2018 / Published: 11 August 2018
(This article belongs to the Special Issue Efficient Technology for the Pretreatment of Biomass)
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This paper presents results for a comprehensive study that compares the performance of three electricity-based thermal pretreatment methods for improving the effectiveness of anaerobic digestion (AD) to process municipal wastewater sludge. The study compares thermal pretreatment using conventional heating (CH), microwave (MW), and radio frequency (RF) heating techniques. The effectiveness of the pretreatment methods was assessed in terms of chemical oxygen demand (COD) and biopolymers solubilization, AD bioenergy production, input electrical energy, and overall net energy production of the sequential pretreatment/AD process. The heating applicators for the bench-scale testing consisted of a custom-built pressure-sealed heating vessel for CH experiments, an off-the-shelf programmable MW oven operating at a frequency of 2.45 GHz for MW heating experiments, and a newly developed 1 kW RF heating system operating at a frequency of 13.56 MHz for RF heating experiments. Under identical thermal profiles, all three thermal pretreatment methods achieved similar sludge disintegration in terms of COD and biopolymer solubilization as well as AD bioenergy production (p-value > 0.05). According to the energy assessment results, the application of CH and MW pretreatments resulted in overall negative energy production, while positive net energy production was obtained through the sequential pretreatment/AD process utilizing RF pretreatment. View Full-Text
Keywords: anaerobic digestion; bioenergy; municipal sludge; solubilization; thermal pretreatment anaerobic digestion; bioenergy; municipal sludge; solubilization; thermal pretreatment

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Hosseini Koupaie, E.; Johnson, T.; Eskicioglu, C. Comparison of Different Electricity-Based Thermal Pretreatment Methods for Enhanced Bioenergy Production from Municipal Sludge. Molecules 2018, 23, 2006.

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