Lasse Rosendahl

Aalborg University · AAU Energy

Accurately estimating the complex motion of the heart can unlock enormous potential for kinetic energy harvesting. This paper presents a foundational dataset for heart kinetic motion through in-vivo tests and investigates the most influential factors in heart kinetic motion. In-vivo tests on a living pig's heart, with signal processing, were carrie...

Industrial and municipal wastes remain significant sources of air, soil, and water pollution, thus causing adverse climate and health impacts. EU faces challenges in developing green recycling processes and reducing GHG emissions. Innovation in green catalysis is a key driver toward the fulfilment of these goals. This study demonstrated a single-st...

Hydrothermal liquefaction (HTL) bio-crude is known as a potential alternative to conventional fossil fuels in the existing infrastructure. Although HTL has enormous potential as a process for renewable fuel production, developing economically viable HTL-based value-chains has encountered extensive challenges owing to the contaminants and the comple...

Aiming toward improved energy conversion in piezoelectric energy harvesters, this study investigates four-point bending (FPB) energy harvesters (FPB-EH) to explore their prominent features and characteristics. The FPB configuration innovatively extends energy harvesting capabilities relative to conventional cantilever beams. The FPB-EH comprises a...

Higher metallic content in nitrogen-rich hydrothermal liquefaction (HTL) biocrudes is a bottleneck during downstream hydroprocessing, which is necessary for producing drop-in biofuels from urban residues and algal feedstocks. Therefore, this work explores a non-catalytic pathway for effective demetallization of nitrogen-rich HTL biocrudes obtained...

This work addresses the process and economic performance of the production of gasoline and diesel range fuels from urban sewage sludge. The overall production route involves direct conversion of the sewage sludge to an intermediate oil phase, so-called biocrude, via hydrothermal liquefaction at near-critical water conditions and further upgrading o...

Improving the energy conversion efficiency of piezoelectric energy harvesters is of great importance, and one approach is to make more uniform use of the working material by ensuring a uniform strain state. To achieve better performance, this paper presents a four-point bending piezoelectric energy harvester with extensive investigation and modelin...

Hydrothermal liquefaction (HTL) is an efficient method for converting lignocellulosic biomass into biocrude oil (BO). This study investigated the effects of temperature, reaction time, catalyst (K2CO3 or Ru/C), heating rate on product yields, quality and chemical composition of BO. Meanwhile, a comprehensive comparison of fast HTL with conventional...

The melting point of the commercial soldering materials is a limiting factor for the functionality of the thermoelectric generators (TEGs) in medium-temperature ranges higher than 200 $^{\circ}$ C. Hence, using a proper bonding method which could be formed at lower temperatures and withstand higher temperatures is inevitable to unlock the full po...

Hydrothermal liquefaction (HTL) is known to be a promising technology to produce crude bio-oils as intermediate to drop-in transport fuels. However, the co-production of liquefaction wastewater (HTL-AP) and hydrochar residues (HCs) limits the economic viability and technical scalability. Hence, the objective of this work is to study the effect of c...

In this study, Co/γ-Al2O3, Co-Mo/γ-Al2O3, Co/attapulgite (ATP) and Co-Mo/ATP catalysts were prepared and applied for hydrothermal liquefaction (HTL) of sewage sludge (SS) to produce bio-oil. The properties of the catalysts were characterized by various techniques (N2 physisorption, ICP, XRD and XPS). The mesoporous nature of synthesized catalysts w...

Improving the energy conversion efficiency of piezoelectric energy harvesters is of great importance, and one approach is to make more uniform use of the working material by ensuring a uniform strain state. To achieve better performance, this paper presents a four-point bending piezoelectric energy harvester with extensive investigation and modelin...

Within the Vibration Piezoelectric Energy Harvesting (VPEH) framework, this paper investigates and designs an optimal piezoelectric harvester (PH) under stochastic real-time vibrations using a step-by-step guideline from an electrical and mechanical perspective. A stochastic-excitation high-order-shear-deformation finite element (FE) method, with e...

Hydrothermal liquefaction (HTL) has shown great potential to convert sewage sludge (SS) with high moisture into bio-crude. However, the disposal and reutilization of hydrothermal liquefaction wastewater (HTLWW) is a critical issue. Anaerobic digestion (AD) is proven to be an alternative to treat organic wastewater. Therefore, energy recovery from h...

Aqueous phase recirculation (APR) during the hydrothermal liquefaction (HTL) process is a means to enhance HTL performance and lower the need for intensive residual water treatment. However, the obtained HTL bio-crude cannot be considered a drop-in biofuel partially due to its significant heteroatom content. Thus, catalytic hydrotreating is typical...

This paper investigates self-powering online condition monitoring for rotating machines by the piezoelectric transducer as an energy harvester and sensor. The method is devised for real-time working motors and relies on self-powered wireless data transfer where the data comes from the piezoelectric transducer’s output. Energy harvesting by Piezocer...

As the literature lacks any systematic study upon the sol–gel process from the process point of view, herein the current work, the influence of key operating parameters including F127/TEOS ratio, Aging time, and calcination rate upon final product textural and bulk properties is aimed to be screened using response surface methodology (RSM). Under u...

Triboelectric nanogenerator (TENG) is a new category of efficient technologies for energy harvesting applications. It has been shown as a promising method for converting low-frequency mechanical motions into electrical energy. The amount of power generated and its optimization are the most important criteria in the design of TENGs. However, some im...

Hydrothermal liquefaction (HTL) of biomass is establishing itself as one of the leading technologies for the conversion of virtually any type of biomass feedstock into drop-in biofuels and renewable materials. Several catalysis strategies have been proposed for this process to increase the yields of the product (biocrude) and/or to obtain a product...

The aim of this paper is to evaluate the costs and GHG emissions of advanced biofuels production through hydrothermal liquefaction (HTL) of sewage sludge in The Netherlands targeting the marine fuels market. The process evaluated consists of a distributed configuration of regional HTL plants co-located with wastewater treatment plants, with central...

In the present study, the protein-extracted grass residue (press cake) was processed through hydrothermal liquefaction under sub and supercritical temperatures (300, 350 and 400 °C) with and without using a potassium carbonate catalyst. The results revealed that bio-crude yield was influenced by both temperature and the catalyst. The catalyst was f...

In the current study, the electrical responses of a thermoelectric (TE) module and a photovoltaic (PV) cell are investigated in three different systems, namely, a PV-only system, TE-only system, and hybrid TE-PV system with a beam splitter (TE-PV-BS), under variable solar irradiations demonstrating partly cloudy weather conditions. To enhance the d...

Lignin liquefaction process under catalyst-free conditions in a temperature range from 573 K to 647 K is investigated with this mathematical model. Based on the theoretical understanding of the physical and chemical processes of the liquefaction process in subcritical temperatures, a comprehensive mathematical model for the decomposition of lignin...

As the applications of thermoelectric generators (TEGs) have become more extensive in last decades, the transient characteristics of TEGs have gradually attracted attention. The current transient studies on TEG systems, however, mostly rely on simulation learning. Moreover, the small number of designed experiments mostly considered a single heating...

An experimental study is carried out to investigate performance of three different solar energy harvesting systems. The critical electrical outputs of a photovoltaic (PV) cell and a thermoelectric generator (TEG) namely voltage, current and maximum power generation are obtained in a PV-only and a TEG-only system. The results are compared with perfo...

This study demonstrates the co-hydrodeoxygenation of partially upgraded bio-oil (PUB) obtained from hydro-thermal liquefaction of pinewood, with rapeseed oil (RO) to produce bio-derived drop-in fuel. Enhanced miscibility of PUB in RO showed the high potential of HTL bio-oil for co-processing with different refinery streams in existing refineries. C...

This study focuses on the valorization of the organic fraction of municipal solid waste (biopulp) by hydrothermal liquefaction. Thereby, homogeneous alkali catalysts (KOH, NaOH, K2CO3, and Na2CO3) and a residual aqueous phase recirculation methodology were mutually employed to enhance the bio-crude yield and energy efficiency of a sub-critical hydr...

The potential of using cold water brown macroalgae Fucus vesiculosus for biocrude production via non-catalytic supercritical hydrothermal liquefaction (HTL) was studied. Demineralization, residue neutralization, and high value-added product (alginate and fucoidan) extraction processes were carried out before using the biomass for HTL biocrude produ...

Recent environmental regulations have urged refiners to decrease NOx emissions related to fuels particularly used in marine transportation. To this, hydrodenitrogenation (HDN) of Iranian Vacuum Bottom (IVB), as one of the most abundant but problematic effluents of Iranian refineries used for marine applications, was evaluated for the very first tim...

In this contribution, we successfully applied demineralization (i.e., solvent-assisted separation and acid washing) for the removal of carbonaceous solids and inorganics from a biocrude obtained from the catalytic hydrothermal liquefaction (HTL) of Miscanthus. The experimental results of all six employed acids showed that 0.1 M H2SO4 was the most e...

The management and optimization of the aqueous phase are the major challenges that hinder the promotion of hydrothermal liquefaction (HTL) technology on a commercial scale. Recently, many studies reported about the accumulation of the N-content in the bio-crude with continuous recycling of the aqueous phase from high protein-containing biomass. In...

Due to its capability to produce negative CO2 emissions, bioenergy in combination with carbon capture and storage (BECCS) has been identified as a key technology to limit global warming and to support the energy transition in pursue of the climate targets of this century. Among different bioenergy applications, advanced liquid biofuels produced thr...

Among different carbon sources, biomass is the most abundant organic carbon source available for producing renewable bio-oils and the value-added chemicals. Hydrothermal liquefaction (HTL) is a green method for sustainable transformation of dry and wet waste biomass to bio-oils and chemical products that are potentially applicable as raw materials...

Hydrothermal liquefaction (HTL) is an effective technology for bio-crude production. To date, various co-liquefaction studies were performed with contrasted (different composition) biomasses in subcritical water. Therefore, the present study investigated co-hydrothermal liquefaction of similar kinds of lignocellulosic biomasses (wheat straw, eucaly...

Knowing the nature of damping in piezoelectric energy harvesters can lead to proper damping and electromechanical models and designing highly efficient harvesters with less damping. As an attempt toward a better understanding of damping in piezoelectric energy harvesters, this paper presents experimental results for structural and viscous air dampi...

This study investigates the integration of a biomass mechanical pretreatment technology and hydrothermal liquefaction for the valorization of biopulp; the organic fraction of municipal solid waste. A preliminary screening of the hydrothermal liquefaction conditions was carried out to investigate the impact of temperature (350 and 400 •C) and the pr...

Utilizing thermoelectric generators (TEGs) is increasing in many industrial applications due to its advantages. Heat rejection from cold side of a TEG module is a substantial parameter to improve conversion efficiency of the module. One of the easy-to-use cooling approaches is using direct current (DC) fans. This study investigates a self-cooling T...

Waste cooking oil (WCO) is generally considered a global waste but with prospective for secondary use such as fuels or chemicals. In the present work, functionalizing of WCO to polymeric surfactants through a cleaner approach with high emulsification ability for enhanced oil recovery (EOR) of fossil crude and enhanced biocrudes solubility in petrol...

In the present study, eucalyptus biomass was processed to produce biocrude via hydrothermal liquefaction. The effect of process conditions (temperature, alkali catalyst) was initially investigated. The maximum biocrude yield (35.78%, daf) was achieved at subcritical conditions (350 ̊C-catalyst) and comparatively lower at supercritical conditions. T...

Toward the accurate electrical and mechanical modulations of the piezoelectric harvester, this paper presents a unified electromechanical-coupled voltage equation and a damping determination method. A single differential equation for the voltage is obtained that accommodates mechanical and electrical physics for which the exact transient solution i...

Hydrothermal liquefaction (HTL) is a promising technology for converting organic-rich waste biomass such as swine manure (SM) and sewage sludge (SS) into energy-dense bio-crude. Until now, one of the major challenges associated with HTL is the pumpability of high dry-matter containing fibrous feedstocks for continuous processing. In this context, t...

The technical and economic feasibility to deliver sustainable liquid biocrude through hydrothermal liquefaction (HTL) while enabling negative carbon dioxide emissions is evaluated in this paper, looking into the potential of the process in the context of negative emission technologies (NETs) for climate change mitigation. In the HTL process, a gas...

Achieving high power densities through initiative designs of piezoelectric harvester in various geometries is a key point in vibration energy harvesting. State-of-the-art analytical and finite element models (FEMs) ignore structural damping, inter-laminar continuity, shear stresses, and contact layer effect between the substrate and piezoelectric l...

Heavy metals (HMs) are undoubtedly an unavoidable nuisance in today's era, and their appropriate handling and disposal carry the utmost significance. Construction wood (CW), specifically hazardous and non-hazardous wood is contaminated due to a mixture of different materials like paints, coatings, and copper layers, etc. that need proper attention...

The NextGenRoadFuels Horizon 2020 project, started in November 2018, will prove the Hydrothermal Liquefaction (HTL) pathway as an efficient route to produce high-volume, cost-competitive drop-in synthetic gasoline and diesel fuels as well as other hydrocarbon compounds.In NextGenRoadFuels, biogenic urban resources such as sewage sludge from treated...

The technical and economic feasibility to deliver sustainable liquid biocrude through hydrothermal liquefaction (HTL) while enabling negative carbon dioxide emissions is evaluated in this paper, looking into the potential of the process in the context of negative emission technologies (NETs) for climate change mitigation. In the HTL process, a gas...

Zinc-antimonide is an encouraging alternative thermoelectric material to bismuth telluride based material for medium temperature range applications. In this work two fabrication concepts are proposed to build flexible modules using P-type zinc-antimony thin film and constantan straps, where the constantan was used as flexible electrical interconnec...

Portland cement is produced by one of the highest energy-consumptive industrial processes. Within the process, the rotary kiln represents one of the major sources of thermal energy loss. Based on the lengthwise temperature profile of the kiln, an optimal placement for heat recovery is identified based on the highest surface temperatures. This study...

Effective catalytic hydrotreatment of highly nitrogenous biocrudes derived from the hydrothermal liquefaction (HTL) of primary sewage sludge and microalga Spirulina biomass was explored. A critical issue is the lack of thermal stability of raw HTL biocrudes at the severe conditions (~400 °C) required for hydrodenitrogenation. This fact suggests the...

Wood liquefaction in hot compressed water is modeled using the hydrolysis of Cellulose, Hemicellulose, and Lignin. These three components are reacted under catalyst-free subcritical conditions in a temperature range from 553 K to 640 K, and the heating rate ranges from 2 K/min to 6 K/min. Using a simplified reaction scheme, water-soluble products 1...

The solubility behavior of three renewable bio-liquids obtained from hydrothermal liquefaction, rapeseed oil, and two common refinery streams is investigated. 242 solubility tests are performed, which lay the foundation for testing three different solubility approaches, namely: Hildebrand, Wiehe, and Hansen solubility parameters, and gaining a bett...

Intense farming activities and the growth of the population produce increasing amounts of wastes, which represent an environmental concern and require an adequate disposal. Animal manure, fish sludge, and sewage sludge are all wet wastes consisting of organic, but also inorganic material. Hydrothermal liquefaction is proposed to treat these wastes...

Effective catalytic hydrotreatment of highly nitrogenous biocrudes derived from the hydrothermal liquefaction (HTL) of second (sewage sludge) and third (microalga Spirulina) generation biomass was explored. A critical issue is the lack of thermal stability of raw HTL biocrudes at the severe conditions (~400 {\deg}C) required for hydrodenitrogenatio...

In this study, hydrothermal liquefaction (HTL) of wheat straw (WS) in sub (350 °C) and supercritical (400 °C) water with and without alkali catalyst was performed to investigate the potential of WS for the production of biocrude. The influences of temperature and catalyst were studied for the HTL products. Results showed that maximum biocrude yield...

Hydrothermal processes enable an effective conversion of waste biomasses into fuels and carbonaceous materials. Covering the heat requirements with concentrated solar energy is a clever strategy to increase the plant efficiency and pursue the principles of circular economy. With the purpose of producing liquid and solid biofuels through zero-energy...

Using phase change materials (PCMs) is an efficient technique to thermal management of a thermoelectric generator (TEG) system. In this paper a TEG, integrated with PCMs, is investigated and optimized to achieve maximum thermal to electrical conversion efficiency by the TEG. Finite element simulation of the system performance is implemented in Mult...

This paper presents an initiative concept in geometry and material lay-up toward energy conversion enhancement of piezoelectric energy harvesters from wideband excitation signals. The energy harvester demonstrated in this work has Macro-fiber-composite (MFC) as active layers and composite laminate as the center shim. This concept utilizes variable...

Large-scale commercialization of drop-in biofuel technologies require a deeper understanding of the molecular structure of biocrude oils and their compatibility with fossil crudes in term of molecular interactions that govern miscibility. For the first time, the compatibility of hydrothermal liquefaction (HTL) derived biocrude obtained from pinewoo...

Results • The temperature had a negligible influence on bio-crude yield and quality, whereas catalyst (K 2 CO 3) slightly improved both the yield and quality. • The overall, 58-67% of the carbon went into the bio-crude at both sub and supercritical conditions. • The bio-crude at supercritical conditions contained lower nitrogen, which indicates tha...

Concentrated photovoltaic (CPV) modules experience a reduction in the conversion efficiency with increasing in the cell temperature as a result of long wavelength solar irradiation which is not absorbed by the cell’s band gap. Separation of long wavelength solar spectrum from the solar irradiation helps to fully utilize the solar irradiation as a p...

Based on the literature, Co-precipitation process has been narrowly studied from the “process” point of view thus far, which has led to the majority of this complex phenomenon remains unknown scientifically. This work firstly tries to deeply screen the synthesis procedure of γ-Alumina in terms of precipitation, whereas such key parameters ruling th...

Hydrothermal liquefaction (HTL) is a promising technology for the production of bio-crude. However, some unresolved issues still exist within HTL, which need to be resolved before its promotion on a commercial scale. The management of the aqueous phase is one of the leading challenges related to HTL. In this study, the sewage sludge has been liquef...

A generic approach is proposed for the estimation of advanced biocrudes properties from liquefied biomass and the enthalpy of formation of biomass feedstocks applicable to the modeling of biomass conversion processes where the exact stoichiometry and kinetics are unknown, such as pyrolysis, solvolysis and hydrothermal liquefaction. The enthalpy of...