Publications de Rudolf Paul Wilhelm Jozef Struis

Relating alkali release from a wood pellet with combustion progress: A modified random pore model supportive study

Christian Ludwig, Marco Wellinger, Rudolf Paul Wilhelm Jozef Struis

This paper concerns a miniature gasifier fed with a constant ambient-pressure flow of air to study the pyrolysis and subsequent combustion stage of a single wood pellet at T = 800 ℃. The alkali release and the concentration of simple gases were recorded si ...

EnPress Publisher2024

Surfactant-based enrichment of rare earth elements from NdFeB magnet e-waste: Optimisation of cloud formation and rare earths extraction

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Mohamed Tarik, Ajay Bhagwan Patil

Appropriate waste and resource management are essential for a sustainable circular economy with reduced environmental impact. With critical resources, e-waste may serve as indirect raw material. For example, with NdFeB permanent magnets, Neodymium (Nd) and ...

2023

Separation and Recycling Potential of Rare Earth Elements from Energy Systems: Feed and Economic Viability Review

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Viktoria Paetzel, Ajay Bhagwan Patil

This review explores the potential of separating and recycling rare earth elements (REEs) from different energy conversion systems, such as wind turbines, electric vehicles batteries, or lighting devices. The REEs include 17 elements (with global productio ...

2022

Insights about inductively coupled plasma optical emission spectroscopy interferences of major rare earth elements in complex e-waste feeds

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Mohamed Tarik, Ajay Bhagwan Patil

The advent of rare earth elements (REEs) with optoelectronic properties has shifted the technology paradigm from digital to a smart and hybrid world. Their substantial uses also resulted in a large piling up of e-waste. Therefore, e-waste is now a lucrativ ...

2022

Opportunities in Critical Rare Earth Metal Recycling Value Chains for Economic Growth with Sustainable Technological Innovations

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Ajay Bhagwan Patil

Rare earth elements (REEs) are often referred to as the industrial vitamins and the key drivers of the industry 4.0 revolution. The current global supply chain of REEs for green and high-tech applications with more than 220 metric kilotons per year involve ...

2022

Exploiting end-of-life lamps fluorescent powder e-waste as a secondary resource for critical rare earth metals

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Mohamed Tarik, Ajay Bhagwan Patil

The consensus is growing for the UN sustainable development goals regarding responsible consumption, production, and climate actions. Because of growth towards a digital society (“industry 4.0 revolution”), it is needed to have our resources and economies ...

2021

Extraction of Rare Earth Metals: The New Thermodynamic Considerations Toward Process Hydrometallurgy

Andrea Testino, Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Ajay Bhagwan Patil

Successful management of secondary waste resources is essential for the viable circular economy. E-waste could serve as the potential urban mining source for the alternative supply chain of critical metals such as rare earth elements (REEs). The hydrometal ...

Springer Nature Switzerland AG2021

On-line liquid quench sampling and UV–Vis spectroscopy for tar measurements in wood gasification process gases

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis

In biomass gasification processes, the formation and handling of tars are of major concern. Robust and versatile analytical tools are needed to on-line monitor tar compound concentrations in process gases from lab- to industrial scale. This study addresses ...

Elsevier2016

Review of fly ash inertisation treatments and recycling

Rudolf Paul Wilhelm Jozef Struis

Fly ash (FA) is a by-product of power, and incineration plants operated either on coal and biomass, or on municipal solid waste. FA can be divided into coal fly ash, obtained from power plant burning coal, flue gas desulphurisation FA, that is, the by-prod ...

Springer Verlag2014

Inertisation of heavy metals in municipal solid waste incineration fly ash by means of colloidal silica – a synchrotron X-ray diffraction and absorption study

Rudolf Paul Wilhelm Jozef Struis

Many efforts have been undertaken in past decades to minimize pollution from municipal solid waste incineration fly ash (MSWI FA). This residue is toxic, because of its high concentration of heavy metals, mainly Pb and Zn. A new method for heavy metals ent ...

RSC Publishing2013

Redox dynamics of sulphur with Ni/GDC anode during SOFC operation at mid- and low-range temperatures: An operando S K-edge XANES study

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis

Sulphur poisoning of nickel-based solid oxide fuel cell (SOFC) anode catalysts is a well-documented shortcoming, but not yet fully understood. Here, a novel experiment is demonstrated to obtain spectroscopic information at operando conditions, in particula ...

Elsevier2013

Piezoresistive Ni:a-C:H thin films containing hcp-Ni or Ni3C investigated by XRD, EXAFS, and wavelet analysis

Rudolf Paul Wilhelm Jozef Struis

Elsevier2013

Integrated Minerals Recycling In Biofuel Production – The Sunchem Process

Martin Brandenberger, Andrea Testino, Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Mariluz Bagnoud, Frédéric Vogel

2011

Sulphur poisoning of Ni catalysts in the SNG production from biomass: A TPO/XPS/XAS study

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Tilman J. Schildhauer

Ni-based catalysts are prone to deactivation (poisoning) of their active surface sites by sulphur and carbon species contained in the gas fed to the reactor. This study focuses on Ni/Al2O3-based catalyst samples which had allegedly been deactivated by sulp ...

2009

Studying the Formation of Ni3C from CO and Metallic Ni at T=265 degrees C in Situ Using Ni K-Edge X-ray Absorption Spectroscopy

Alexander Wokaun, Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis

Metallic Ni nanopowder (Ni-0) was monitored during 23 h of carburization (2CO + 3Ni(0) - Ni3C + CO2, T = 265 degrees C) using Ni K-edge X-ray absorption spectroscopy. X-ray diffraction analysis made afterward at room temperature revealed 28 +/- 3% Ni3C amo ...

American Chemical Society2009

The Fate of Lead in MSWI-Fly Ash During Heat Treatment: An X-Ray Absorption Spectroscopy Study

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis

Wiley-Blackwell2009

Studying sulfur functional groups in Norway spruce year rings using S L-edge total electron yield spectroscopy

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis

Profiles of the major sulfur functional groups in mature Norway spruce wood tissue have been established for the first time. The big challenge was the development of a method suitable for sulfur speciation in samples with very low sulfur content (

Elsevier2008