Gunther Kolb

Chemical micro process engineering : processing and plants

Preface. Abbreviations and Symbols. 1. Mixing of Miscible Fluids. 1.1 Mixing in Micro Spaces Drivers, Principles, Designs and Uses. 1.2 Active Mixing. 1.3 Passive Mixing. 2. Micro Structured Fuel Processors for Energy Generation. 2.1 Outline and Definitions. 2.2 Factors Affecting the Competitiveness of Fuel Processors. 2.3 Design Concepts of Micro Structured Reactors for Fuel Processing Applications. 2.4 Micro Structured Test Reactors for Fuel Processing. 2.5 Combustion in Micro Channels as Energy Source for Fuel Processors. 2.6 Micro Structured Reactors for Gas Purification (CO Clean up). 2.7 Integrated Micro Structured Reactor Fuel Processing Concepts. 2.8 Comparison of Micro Structured Fuel Processor Systems with Conventional Technologies. 2.9 Fabrication Techniques for Micro Structured Energy Generation Systems. 3. Catalyst Screening. 3.1 Introduction. 3.2 Catalyst Preparation Methodology. 3.3 Parallel Batch Screening Reactors. 3.4 Screening Reactors for Steady Continuous Operation. 3.5 Reactors for Transient/Dynamic Operation. 3.6 Computational Evaluation Methods. 4. Micro Structured Reactor Plant Concepts. 4.1 Micro Reactor or Micro Structured Reactor Plant (MRP). 4.2 Applicable Principles for Micro Structured Reactor Plant (MRP) Design. 4.3 Process Conception and Economics. 4.4 Early Concepts for Micro Structured Reactor Plant Design. 4.5 Fluidic and Electrical Interconnects Device to Device and Device to World. 4.6 Table Top Laboratory Scale Plants. 4.7 Hybrid Plants. 4.8 Mobile Plants. 4.9 Production Plants. 4.10 Plant Installations and Supplier specific Assemblies. 4.11 Process Management. 4.12 Process Engineering. 4.13 New Processes for Cost efficient Reactor Manufacturing. Subject Index.

Detailed Characterization of Various Porous Alumina-Based Catalyst Coatings Within Microchannels and Their Testing for Methanol Steam Reforming

A fundamental study concerning the preparation of porous alumina washcoats in microchannels for the application in heterogeneous gas phase catalysis was performed, focusing on the pre-treatment of the microstructures, properties, and adhesion of the washcoats as well as the testing of the prepared catalysts. Steel microstructures, which are manufactured by wet-chemical etching with chloride solutions, show significant chlorine content at the surface due to the etchant. Anodic oxidation and thermal treatment of the microstructures significantly reduce the undesirable chlorine content, which is assumed to have deleterious effects on the catalyst activity. Good adhesion of the porous catalysts, deposited by a two-step process, washcoating and wet impregnation, was demonstrated by a mechanical test. Cross-sectional profile accuracy was reasonable and reliable. At the example of a CuO/Cr 2 O 3 /Al 2 O 3 system, the distribution of the impregnated components within the washcoat, in lateral (depth of the coating) and horizontal directions (at the coatings surface), was studied by secondary ion mass spectrometry (SIMS). It turned out that Cr 2 O 3 was homogeneously distributed both in horizontal and lateral direction, whereas the content of CuO decreased with the washcoat depth and islands of accumulated material on the surface were formed. The activity of the CuO/Cr 2 O 3 /Al 2 O 3 system was investigated using different alumina carriers for methanol steam reforming. The activity found was correlated with the total catalyst surface area offered to the reaction system.

Low temperature catalytic combustion of propane over Pt-based catalyst with inverse opal microstructure in a microchannel reactor

A novel Pt-based catalyst with highly regular, periodic inverse opal microstructure was fabricated in a microchannel reactor, and catalytic testing revealed excellent conversion and stable activity for propane combustion at low temperatures.

A Methanol Steam Micro-Reformer for Low Power Fuel Cell Applications

Abstract A micro-reformer was fabricated and its performance investigated using copper-zinc catalysts with differing compositions and loadings at various operating conditions. A catalyst with 3:1 copper-to-zinc ratio and 8 wt% loading produced enough hydrogen to power a 28W PEM fuel cell when using a third of the reformers volume (8 cm3) and assuming 64% fuel cell efficiency. Methanol conversion was 65% while hydrogen content in the off-gas was 45% at a temperature of 275°C and residence time of 0.11s. Carbon monoxide levels were approximately 1.45%. Higher methanol conversions (80%) and hydrogen content in the off-gas (50%) were achieved by a second catalyst with 16 wt% at 290°C while utilizing the entire reformer volume. Hydrogen yield and selectivity were high (78 and 98% respectively). Extrapolating from present results, the maximum power output possible to be achieved by this device is 84 W.

Microstructured fuel processors for fuel-cell applications

Microstructured reactors are being developed at IMM for the processing of various fuels to provide hydrogen for mobile and portable fuel-cell systems. The key feature of the systems is the integrated-plate heat-exchanger technology, which allows for thermal integration of several functions in a single device. For example, steam reforming may be coupled with exothermic reactions in separate flow-paths of a heat exchanger. Catalyst coatings are also under development for numerous reactions, such as propane steam reforming, methanol steam reforming, catalytic combustion, water-gas shift, and preferential oxidation of carbon monoxide. These catalysts are being investigated in specially developed testing reactors. Reactors and complete fuel processors are being tested up to 5 kW power output of the corresponding fuel cell.

Energy-efficient routes for the production of gasoline from biogas and pyrolysis oil—process design and life-cycle assessment

Two novel routes for the production of gasoline from pyrolysis oil (from timber pine) and biogas (from ley grass) are simulated, followed by a cradle-to-gate life-cycle assessment of the two production routes. The main aim of this work is to conduct a holistic evaluation of the proposed routes and benchmark them against the conventional route of producing gasoline from natural gas. A previously commercialized method of synthesizing gasoline involves conversion of natural gas to syngas, which is further converted to methanol, and then as a last step, the methanol is converted to gasoline. In the new proposed routes, the syngas production step is different; syngas is produced from a mixture of pyrolysis oil and biogas in the following two ways: (i) autothermal reforming of pyrolysis oil and biogas, in which there are two reactions in one reactor (ATR) and (ii) steam reforming of pyrolysis oil and catalytic partial oxidation of biogas, in which there are separated but thermally coupled reactions and reactors (CR). The other two steps to produce methanol from syngas, and gasoline from methanol, remain the same. The purpose of this simulation is to have an ex-ante comparison of the performance of the new routes against a reference, in terms of energy and sustainability. Thus, at this stage of simulations, nonrigorous, equilibrium-based models have been used for reactors, which will give the best case conversions for each step. For the conventional production route, conversion and yield data available in the literature have been used, wherever available.The results of the process design showed that the second method (separate, but thermally coupled reforming) has a carbon efficiency of 0.53, compared to the conventional route (0.48), as well as the first route (0.40). The life-cycle assessment results revealed that the newly proposed processes have a clear advantage over the conventional process in some categories, particularly the global warming potential and primary energy demand; but there are also some in which the conventional route fares better, such as the human toxicity potential and the categories related to land-use change such as biotic production potential and the groundwater resistance indicator. The results confirmed that even though using biomass such as timber pine as raw material does result in reduced greenhouse gas emissions, the activities associated with biomass, such as cultivation and harvesting, contribute to the environmental footprint, particularly the land use change categories. This gives an impetus to investigate the potential of agricultural, forest, or even food waste, which would be likely to have a substantially lower impact on the environment. Moreover, it could be seen that the source of electricity used in the process has a major impact on the environmental performance.

Development of reformed ethanol fuel cell system for backup and off-grid applications — system design and integration

This work presents a crude bioethanol fueled integrated power system for backup and off-grid applications. The system is based on ethanol steam reformation to hydrogen that is used in polymer electrolyte fuel cells to produce electricity. We introduce the system design and overall system specifications, and report the experimental process of defining specifications for the produced hydrogen quality, a key variable affecting the final system cost, efficiency and durability. Results from development of individual subsystems are also presented together with discussion on the complete system integration.

BIOGO : contributing to the transformation of the petrochemical industry through advances in nanocatalysts and reactor design

*Corresponding author: Gunther Kolb, Decentralized and Mobile Energy Technology Department, Fraunhofer ICT-IMM, Carl-ZeissStraße 18-20, 55129 Mainz, Germany, E-mail: Gunther.Kolb@imm.fraunhofer.de Hannah Newton: C-Tech Innovation Ltd, Capenhurst Technology Park, Capenhurst, Chester CH1 6EH, UK Qi Wang and Smitha Sundaram: Department of Chemical Engineering and Chemistry, Eindhoven Technical University, Postbus 513, Eindhoven 5600MB, The Netherlands Andre van Veen: School of Engineering, University of Warwick, Coventry CV4 7AL, UK Stefan Kiesewalter: Strategic Management, Fraunhofer ICT-IMM, Carl-Zeiss-Straße 18-20, 55129 Mainz, Germany Project profile

Energy systems for a greener future

The Energy Technology and Catalysis Department at Fraunhofer ICT-IMM covers the entire technology chain, with expertise in the areas of catalyst development and stability testing, process simulation, system design and control, development of cheaper fabrication techniques, reactor construction and complete system integration and testing (Figure 1). With a staff of 20 people, the group can be considered as one of the largest for fuel processing development in Europe. In addition to the development of single components and complete fuel processing systems for conventional and regenerative fuels, other business interests lie in the fields of liquid hydrogen technology, exhaust gas treatment systems and biofuel syntheses. The microstructured and microchannel reactors, together with the integrated catalysts therein, allow for the realization of compact and consolidated systems, which is crucial for both mobile and stationary applications. A performance range from 100 W to over 100 kW can be covered. Microstructured plate heat exchanger reactors open new opportunities for heterogeneously catalyzed gas phase reactions with respect to enhanced heat and mass transfer, resulting in shorter residence times via an intelligent coupling of endothermic and exothermic reactions, or even cooling functions. However, processing steps other than the generation of hydrogen can benefit from this integrated coupling. Process steps further downstream, such as water gas shift, preferential oxidation and selective methanation of carbon monoxide, are required to yield hydrogen to the required level of (hydrogen) purity. Meanwhile, the number of successfully demonstrated applications is numerous, especially when one includes bio-based feedstocks as potential, processable feedstock, as illustrated in Figure 2. Of course, processing of logistic fuels such as methane, methanol, ethanol, Liquefied Petroleum Gas (LPG) and diesel are also very active working fields.

Micro-Structured Evaporators for Laboratory Applications and Mobile Power Generation

Different microstructured evaporator concepts are presented, namely a small scale laboratory evaporator driven by electrical energy, a hot gas driven 5 kW evaporator and an evaporator for methanol steam supply to a catalytic start-up burner of a 500 W DMFC system.Copyright