Low-Fouling Heat Exchanger for Biofuel Usage in Combined Heat and Power Units

Abstract

Micro combined heat and power units (mCHP) are efficient energy systems for residential applications. With biogas as renewable energy source, the full potential of this technology would be released. Especially in rural areas, where centralized heating systems are rare, biogas is most likely available. However, there are disadvantages compared to natural gas that inhibited the usage of biogas in mCHP until now. First of all biogas is not as clean as natural gas and comprises various components according to its production conditions and raw material input. This leads to a higher rate of soot particles and pollutants in the exhaust gas. Consequently, fouling in the downstream heat exchanger (HE) is a serious issue when operating biogas in mCHPs. One approach to solve this problem is the identification of a fouling resistant coating for the HE surface in contact with the flue gas. This is complemented with a redesign of the HE to improve coatability and cleanability. This work presents the proceeding to evolve a fouling resistant HE for operating biogas in mCHPs.

Additional information

Funding

Funding from German Federal Environmental Foundation (Deutsche Stiftung Umwelt – DBU reference number 29108) and the technical advice by Dr. Jürgen Weiser from intelli Engineering GmbH is gratefully acknowledged.

Notes on contributors

Steffi Höft

Steffi Höft was a research assistant at the Institute for Chemical and Thermal Process Engineering, Technische Universität Braunschweig, Germany (ICTV Research Group Fouling & Cleaning). In 2010 she received a Dipl.-Ing. degree in Biological Process Engineering from the Technische Universität Braunschweig. Currently she is working at BMA AG in Braunschweig.

Sebastian Grahn

Sebastian Grahn received his Dipl.-Ing. degree in Mechanical Engineering from the Otto-von-Guericke-Universität Magdeburg in 2009. Following his studies, he worked as development engineer at intelli engineering GmbH. Since 2016, he is research assistant at the Chair of Machine Elements and Tribology at Otto-von-Guericke-Universität Magdeburg. His fields of activity are automotive projects with single-cylinder engines and all-wheel power trains.

Ingmar Bialuch

Ingmar Bialuch is a researcher at the Fraunhofer Institute for Surface Engineering and Thin Films in Braunschweig/Germany. He received the graduate engineer degree in 1998 from the University of Applied Sciences in Lübeck/Germany. His research interests are modified diamond-like carbon films prepared by plasma assisted chemical vapor deposition (PACVD) techniques.

Wolfgang Augustin

Wolfgang Augustin is a senior researcher at the Institute for Chemical and Thermal Process Engineering, Technische Universität Braunschweig, Germany. He received his Dr.-Ing. in 1992 in Chemical Engineering from Technische Universität Braunschweig. His main research interests are heat and mass transfer, fouling and cleaning and surface interactions on the micro scale level.

Stephan Scholl

Stephan Scholl is a professor of chemical and thermal process engineering at the Technische Universität Braunschweig, Germany. He received his doctorate degree in 1991 from the Technical University of Munich. After 11 years with BASF AG, Ludwigshafen, Germany, he joined Technische Universität Braunschweig in 2002. His main research areas are heat and mass transfer with an emphasis on fouling and viscous systems, separation processes in biotechnological applications, as well as process intensification.