Publications by Christian Ludwig

Related publications (134)

Natural and simulated weathering of polystyrene: A molecular view of the polymeric interface

Christian Ludwig, Florian Frédéric Vincent Breider, Michel Rossi, Tobias Borgmeyer, Lu Zhou

This work presents the changing abundance of surface functional groups (SFGs) on polystyrene (PS) upon weathering within one or a few molecular monolayers from a molecular point of view. PS particles were aged by exposing it to a gas flow of typically (5 % ...

Elsevier BV2024

Extraction of carotenoids from Chlorella vulgaris using green solvents and syngas production from residual biomass

Christian Ludwig, Christof Holliger, Jean-Paul Schwitzguebel, Shivom Sharma

A combined process for carotenoids extraction and efficient bioenergy recovery from the wet microalgae biomass is proposed. High added-value products could thus be extracted prior a hydrothermal gasification of the algal biomass into synthetic natural gas. ...

2017

Recycling rare earth metals from luminescent fibers by solvent extraction

Christian Ludwig, Ajay Bhagwan Patil, Ayush Agarwal, Laura Torrent Fabrega

Rare earth elements (REEs) are known for their specialized optical and electronic properties that have led to their use in a wide range of applications, such as luminescent fibers employed in security papers (e.g., bank notes). Most of the security documen ...

Elsevier BV2025

Heat, Electricity, or Transportation? The Optimal Use of Residual and Waste Biomass in Europe from an Environmental Perspective

Christian Ludwig, Bernhard Steubing

The optimal use of forest energy wood, industrial wood residues, waste wood, agricultural residues, animal manure, biowaste, and sewage sludge in 2010 and 2030 was assessed for Europe. An energy system model was developed comprising 13 principal fossil tec ...

2012

Online elemental analysis of process gases with ICP-OES: A case study on waste wood combustion

Christian Ludwig, Marco Wellinger

A mobile sampling and measurement system for the analysis of gaseous and liquid samples in the field was developed. An inductively coupled plasma optical emission spectrometer (ICP-OES), which is built into a van, was used as detector. The analytical syste ...

Elsevier2012

Transmission of Alkali Aerosols through Sampling Systems

Christian Ludwig, Tilman J. Schildhauer

In biomass gasification, particles such as condensed alkali salts pose a threat on equipment. Due to high loads of condensable tars in the gases, sampling of these particles to liquids and subsequent analysis of the liquid is frequently the method of choic ...

2011

Flow microcapillary plasma mass spectrometry-based investigation of new Al–Cr–Fe complex metallic alloy passivation

Christian Ludwig, Noémie Elise Ott

Al-Cr-Fe complex metallic alloys are new intermetallic phases with low surface energy, low friction, and high corrosion resistance down to very low pH values (0-2). Flow microcapillary plasma mass spectrometry under potentiostatic control was used to chara ...

Elsevier2014

Supercritical water anomalies in the vicinity of the Widom line

Christian Ludwig

Supercritical water is used in a variety of chemical and industrial applications. As a consequence, a detailed knowledge of the structure-properties correlations is of uttermost importance. Although supercritical water was considered as a homogeneous fluid ...

Nature Research2019

A hyphenated SMPS-ICPMS coupling setup: Size-resolved element specific analysis of airborne nanoparticles

Christian Ludwig, Adrian Hess

Physical and chemical characterization of gas borne particles in the nanometer to sub micrometer size range includes knowledge about particle size distribution and chemical composition, possibly with a high time resolution. However, most of the available t ...

Elsevier Sci Ltd2015

The Kinetics of Adsorption and Desorption of Selected Semivolatile Hydrocarbons and H2O Vapor on Two Mineral Dust Materials: A Molecular View

Christian Ludwig, Michel Rossi, Riccardo Iannarelli

A flowing gas experiment using a Knudsen flow reactor was performed on a series of seven semivolatile probe gases interacting with two often used mineral dust materials, namely, coarse Arizona test dust (ATD-C) and kaolinite. The semivolatile probe gases u ...

2022

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

Enhancing Algae Biomass Production by Using Dye-Sensitized Solar Cells as Filters

Mohammad Khaja Nazeeruddin, Christian Ludwig, Shivom Sharma, Peng Qin, Eya Nicodeme

One of the most promising options for decreasing the costs of microalgae production is enhancing the production and reducing the energy demand of the culturing systems and the high surface area requirements. Because microalgae growth requires only specific ...

2021

Thermodynamic-Kinetic Precipitation Modeling. A Case Study: The Amorphous Calcium Carbonate (ACC) Precipitation Pathway Unravelled

Christian Ludwig, Paul Bowen, Andrea Testino, Agnese Carino, Mohammad Reza Andalibi, Frank Pilger

Nine accurate experimental data sets on amorphous calcium carbonate (ACC) formation in dilute solution were collected varying temperature and pH. The entire precipitation process is described using a complete thermodynamic-kinetic model. The thermodynamic ...

American Chemical Society2017

Air Side Contamination in SOFC Stack Testing

Christian Ludwig, Jan Van Herle, Aïcha Hessler-Wyser, Josef Andreas Schuler, Zacharie Wuillemin

Solid Oxide Fuel Cells (SOFCs) are likely candidates for electricity production with high efficiency and promise reasonable fuel tolerance. While fuel impurities are known anode poisons, less attention is brought to air-purity, especially to air-side conta ...

2010

Air Side Contamination in Solid Oxide Fuel Cell Stack Testing

Christian Ludwig, Jan Van Herle, Aïcha Hessler-Wyser, Josef Andreas Schuler, Zacharie Wuillemin

Solid Oxide Fuel Cells (SOFCs) are likely candidates for electricity production with high efficiency and promise reasonable fuel tolerance. While fuel impurities are known anode poisons, less attention is brought to air-purity, especially to air-side conta ...

Elsevier2011

Sintering and coking resistant core–shell microporous silica–nickel nanoparticles for CO methanation: Towards advanced catalysts production

Christian Ludwig, Andrea Testino

Modern engineered materials have to be developed to address specific problems associated to chemical processes that directly affect our society. Catalysts are key materials used for large scale production of at least 90% of the everyday goods. Many energy ...

Elsevier2016

Size-fractionated characterization and quantification of nanoparticle release rates from a consumer spray product containing engineered nanoparticles

Christian Ludwig

This study describes methods developed for reliable quantification of size- and element-specific release of engineered nanoparticles (ENP) from consumer spray products. A modified glove box setup was designed to allow controlled spray experiments in a part ...

Springer Verlag2010

Elemental and Thermo-gravimetric Characterization of Trace Metals in Leaves and Soils as Bioindicators of Pollution in Kyiv City

Christian Ludwig, Ajay Bhagwan Patil

In this study, leaf and soil samples were used as bio-monitors for different alkali and heavy metals at six different locations in Kyiv city. Using x–y plots of the inductively coupled plasma optical emission spectroscopy (ICP-OES) data measured the discre ...

2021

Producing synthetic natural gas from microalgae via supercritical water gasification: A techno-economic sensitivity analysis

Christian Ludwig, Frédéric Vogel, Martin Brandenberger

A techno-economic sensitivity analysis of the production of synthetic natural gas (SNG) via catalytic supercritical water gasification (SCWG) of microalgae produced in raceway ponds (RP), tubular-, or flat-panel-airlift photobioreactors (FPA-PBR) has been ...

Elsevier2013

Siloxane compounds in biogas from manure and mixed organic waste: Method development and speciation analysis with GC-ICP-MS

Christian Ludwig, Debora Foppiano

A novel method for the determination of linear and cyclic siloxane compounds (L2, L3, D3, D4, D5, and D6) in biogas was developed by combining gas chromatography (GC) with inductively coupled plasma mass spectrometry (ICP-MS). Using a continuous liquid que ...

2020