Work

Technoeconomic evaluation of integrating hydrothermal liquefaction in wastewater treatment plants

Year: 2024

Type: article

Abstract: This study presents a techno-economic analysis (TEA) of producing biocrude through hydrothermal liquefaction (HTL), focusing on smaller decentralized HTL plants integrated within wastewater treatment plants (WWTPs) of various sizes. The base case evaluation focuses on the sludges generated at the Fredericia WWTP in Denmark, receiving an organic load of 150k population equivalent (PE). For TEA, a steady-state process simulation is conducted using Aspen Plus®, utilizing a rigorous kinetic HTL-model. The derived mass and energy balances serve as input for the TEA. The findings reveal the significant impact of operational expenditure (OPEX) on overall economics, with utilities, plant maintenace, and salaries constituting a significant proportion of OPEX. Analysis conducted on the Fredericia WWTP indicates that processing 323 kg/h of dry solids feedstock yields 94 kg/h of biocrude at a MBSP of 1.4 €/kg. MBSP varies between 0.9 to 1.8 €/kg across other evaluated plant sizes (0.1 to 1.0 million PE). By considering a sewage sludge handling credit similar to current costs for disposing sewage sludge or digestate, biocrude can be produced at a competitive to crude oil prices for WWTPs larger that 300k PE. Furthermore, sensitivity analysis identifies biocrude yield, labor costs, and sludge dry matter content as key MBSP influencers.

Source: Bioresource Technology

DOI: 10.1016/j.biortech.2024.132030

Authors: Arif Hussain, Konstantinos Anastasakis

Institutions: Aarhus University, Aarhus University Centre for Water Technology

Language: English

Topic: Thermochemical Biomass Conversion Processes

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Affordable and clean energy, Clean water and sanitation, Industry, innovation and infrastructure

Open Access status: hybrid

Estimated APC paid: $4,740