Events at Department of Energy Technology

PhD defence by Muhammad Salman Haider


17.08.2021 kl. 13.00 - 16.00


Muhammad Salman Haider, Department of Energy Technology, will defend the thesis "Demetallization and Catalytic Hydroprocessing of Nitrogen-rich Hydrothermal Liquefaction Biocrudes"


Demetallization and Catalytic Hydroprocessing of Nitrogen-rich Hydrothermal Liquefaction Biocrudes


Muhammad Salman Haider


Professor Lasse Rosendahl


Assistant Professor Daniele Castello


Associate Professor Henrik Sørensen


Associate Professor, Søren Løkke, Aalborg University (Chairman)
Dr. Douglas Eliott, Pacific Northwest National Laboratory (PNNL),USA
Dr. Ursel Hornung, Karlsruhe Institute of Technology, Germany


Evolving concerns regarding climate change, energy security and dependency on fossil fuels for long haul heavy duty transportation have raised environmental awareness and an urge to reduce the overall carbon footprint by exploring sustainable fuel alternatives. In this regard, hydrothermal liquefaction (HTL) combined with catalytic upgrading is a potential promising technology.

This dissertation investigate the nitrogen-rich HTL biocrudes at molecular level and significantly improve and optimize the down-stream processing: demetallization and catalytic hydrotreating. This PhD work has contributed significantly to answering some of the decade-long fundamental questions for effective down-stream processing of nitrogen-rich HTL biocrudes (i.e. (i) pretreatment routes for demetallization and related bottlenecks; (ii) potential problems associated with metalloporphyrins, oxygenates, and basic nitrogenates; (iii) thermal instability of HTL biocrudes and coking propensity; (iv) what is the proper hydrotreating temperature and how to select it?; (v) role of FT-ICR MS and a priori identification of coke precursors; and (vi) catalyst grading in reactor bed and the role of organic contaminants (metals, oxygen, nitrogen etc.) in the selection of different commercial catalysts). This has been achieved by rethinking the way the HTL biocrudes are currently perceived.

This research results in a 335 hours and 165 hours continuous hydrotreating campaign for Spirulina and sewage sludge HTL biocrudes without pressure drop, reactor plugging and catalyst deactivation. In both cases hydroprocessing experiments were stopped because the HTL biocrude feed was completely consumed. Overall, the successful hydrotreating campaigns will help to establish the drop-in biofuels from hydroprocessing of HTL biocrudes and transfer it to industrial relevance.

In a nutshell, this work lay the foundation of being the first step of important new research directions within the field of HTL biocrude. Furthermore, it also advances the present state-of-art of HTL biocrude upgrading with critical thinking and analysis. Overall, this work demonstrates the viability of demetallization via acid washing and smooth continuous hydroprocessing; moreover, it significantly underlines the crucial role of advanced analytics in process optimization.


THE DEFENCE will be IN ENGLISH - all are welcome.





AAU Energy


Pontoppidanstræde 111, Room 1.177