A5018477687- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Process Optimization and Integration
- Advanced Control Systems Optimization
- biodegradable polymer synthesis and properties
- Carbon dioxide utilization in catalysis
- Chemistry and Chemical Engineering
- Fault Detection and Control Systems
- Carbon Dioxide Capture Technologies
- Energy Efficiency and Management
- CO2 Reduction Techniques and Catalysts
- Catalysis for Biomass Conversion
- Smart Grid Energy Management
- Organometallic Complex Synthesis and Catalysis
- Crystallography and molecular interactions
- Flexible and Reconfigurable Manufacturing Systems
- Polyoxometalates: Synthesis and Applications
- Electric Power System Optimization
- Microplastics and Plastic Pollution
- Integrated Energy Systems Optimization
- Reservoir Engineering and Simulation Methods
- Medical and Health Sciences Research
- Advanced Polymer Synthesis and Characterization
- Building Energy and Comfort Optimization
- Graphene and Nanomaterials Applications
RWTH Aachen University
1977-2023
University of Potsdam
2023
Evonik (Germany)
2021
FH Aachen
2018-2019
Institute of Inorganic Chemistry of the Slovak Academy of Sciences
2019
University of Bath
2014-2015
We report a series of Zr(<sc>iv</sc>) 2,2′-bipyrrolidine–salan derived complexes and their exploitation for the ROP <italic>rac</italic>-lactide to afford highly isotactically enriched PLA.
A series complexes based on 2,2′-bipyrrolidine salan ligands have been prepared and either isotactic or heterotactic PLA prepared.
Polylactide is a biodegradable versatile material based on annually renewable resources and thus CO2 -neutral in its lifecycle. Until now, tin(II)octanoate [Sn(Oct2 )] was used as catalyst for the industrial ring-opening polymerization of lactide spite cytotoxicity. On way towards sustainable catalyst, three iron(II) hybrid guanidine complexes were investigated concerning their molecular structure applied to lactide. The could polymerize unpurified technical-grade rac-lactide well...
Abstract New zinc guanidine complexes with N,O donor functionalities were prepared, characterized by X‐Ray crystallography, and examined for their catalytic activity in the solvent‐free ring‐opening polymerization (ROP) of technical‐grade rac ‐lactide at 150 °C. All showed a high activity. The fastest complex [ZnCl 2 (DMEGasme)] ( C1 ) produced colorless poly(lactide) (PLA) after 90 min conversion 52 % molar masses M w =69 100, polydispersity=1.4). tested different monomer‐to‐initiator...
Abstract The penetration of renewable electricity promises an economic advantage for flexible operation energy‐intense processes. One way to achieve is model predictive control (eNMPC), where dynamic optimization problem directly solved at controller level taking into account a process and operational constraints. We apply eNMPC in silico air separation with integrated liquefier liquid‐assist operation. use mechanistic as both plant surrogate. conduct closed‐loop case study over time horizon...
Abstract The availability of reduced‐dimensional, accurate dynamic models is crucial for the optimal operation chemical processes in fast‐changing environments. Herein, we present a reduced modeling approach rectification columns. model combines compartmentalization to reduce number differential equations with artificial neural networks express nonlinear input–output relations within compartments. We apply control an air separation unit. size equation system by 90% while limiting additional...
We present COSMO-CAMPD, a framework for integrated design of molecules and processes based on COSMO-RS.
Four non-toxic, highly active and robust complexes have been used in the ring opening polymerisation of non-purifed lactide to substitute Sn(Oct)<sub>2</sub>.
Abstract The flexible operation of energy‐intensive processes, such as cryogenic air separation, has economic potential due to increasing fluctuations the electricity markets. Multiproduct separation processes with high ratios liquid product are very promising for storable products. We present a process design an integrated liquefication cycle and assist operation, that facilitates ratio operation. use mechanistic dynamic model in steady‐state optimizations covering wide operational range...
Abstract A new aliphatic hybrid guanidine N,O‐donor ligand (TMGeech) and its zinc chloride complex ([ZnCl 2 (TMGeech)]) are presented. This displays high catalytic activity for the ring‐opening polymerization (ROP) of lactide in toluene, exceeding toxic industry standard tin octanoate by a factor 10. The [ZnCl (TMGeech)] is further demonstrated under industrially preferred melt conditions, reaching conversions within seconds. To bridge gap towards sustainable circular (bio)economy, chemical...
Abstract Process concepts have been conceived and evaluated for the amine‐free homogeneous catalyzed hydrogenation of CO 2 to formic acid (FA). Base‐free DMSO‐mediated production FA has shown avoid formation stable intermediates presumably energy‐intensive recovery strategies. Here, we address challenges in development an overall process: from catalyst immobilization isolation. The was achieved using a multiphasic approach ( n ‐heptane/DMSO) ensuring high retention (>99%) allowing facile...
The integration of renewables into the portfolio energy sources implies that dynamic operation intensive processes, such as air separation, may give an economic advantage. Dynamic process can be achieved by applying nonlinear model predictive control (eNMPC). In this work, we present in-silico case study separation under fluctuating electricity prices. Using a day-ahead price profile, offline optimization (DO) problem is solved, which used initial guess to start fast update method deployed...
Zinc phenoxide complexes L
The heteroleptic complex LZnEt [( 1 ); L = MeNacac MeNC(Me)CHC(Me)O] containing the sterically less demanding N , O ‐chelating ketoiminate (MeNacac) ligand was synthesized by reaction of ZnEt 2 with an equimolar amount MeNacacH, whereas two equivalents MeNacacH gave homoleptic Zn 5 . reacts ArOH (Ar 2,6‐Me ‐Ph) ethane elimination and formation LZnOAr ( ). Addition Lewis base dmap (dmap 4‐dimethylamino pyridine) to yielded corresponding acid‐base adducts dmap‐Zn(L)Et 3 dmap‐Zn(L)OAr 4...
Abstract The synthesis of bio‐based and biodegradable plastics is a hot topic in research due to growing environmental problems caused by omnipresent plastics. As result, polylactide, which has been known for years, seen tremendous increase industrial production. Nevertheless, the manufacturing process using toxic catalyst Sn(Oct) 2 very critical. an alternative, five zinc acetate complexes have synthesized with Schiff base‐like ligands that exhibit high activity ring‐opening polymerization...
Abstract Current research concerning industrial demand side management primarily focuses on monetary aspects. Herein, we extend this perspective by assessing whether economically driven measures increasing the flexibility also result in reduced contributions to residual load. For purpose, conduct a simulative study using historic and projected time series for German electricity sector. First, Fourier analysis are performed show that main oscillation price has period length of 12 hr, whereas...
Abstract Invited for this month's cover is the group of Professor Sonja Herres‐Pawlis at RWTH Aachen (Germany). The image illustrates complex yet flexible circular economy (bio)plastics and role a Zn‐based catalyst therein. Research Article itself available 10.1002/cssc.202300192 .