May 3, Hossein Ghezel-Ayagh, Fuel Cell Energy
Advances in Solid Oxide Fuel Cell Power Systems
Abstract: Recent progress in Solid Oxide Fuel Cell (SOFC) materials, performance and manufacturing has triggered the efforts in scale-up of the technology and development of SOFC systems for a gamut of applications. Due to the absence of Carnot cycle limitations, SOFC is highly efficient in electrochemically converting a stream of fuel into electricity as compared to the conventional thermo-mechanical power generation equipment. Emissions from SOFC systems are negligible as the electrochemical power generation process does not produce NOx associated with high temperature flames present in the thermo-mechanical devices such as internal combustion engines.
In addition to very high efficiencies, SOFC power systems have a myriad of benefits as compared to the alternative power generation equipment. SOFC systems have high reliability and very low noise output because very few moving parts are used. SOFC systems maintain the high efficiency profile over a range of size levels, from hundreds of kilowatts to as large a size as an application requires. This size flexibility positions fuel cell technology favorably with respect to capturing diverse emerging distributed generation applications (e.g., hospitals, hotels, university campuses, retail stores, industrial plants, or residential subdivisions).
Fuel flexibility is one of the most important features of the SOFC systems. Because of the high operating temperature of the SOFC (600-1000 °C), system design may be configured to have the capability to operate using a variety of fuel sources, including natural gas, coal syngas, liquid fuels such as diesel and ethanol, and renewable energy sources such as biogas derived from anaerobic digesters or landfills. Large SOFC installations (hundreds of megawatts) operating on gasified coal, natural gas or biogas could replace coal-burning power plants to deliver electricity affordably, with zero emissions, through the electrical transmission and distribution system that exists today.
The potential advantages of higher efficiency, environmental friendliness, and siting flexibility of SOFC have long been recognized. The challenges have been to develop products, which fully realize these goals, have adequate life spans, and competitive costs. A fuel cell power system consists of the fuel cell section and what is referred to as the balance of plant (BOP). The fuel cell section consists of one or more stacks of fuel cells. A stack is a group of individual fuel cells which are physically held together, are fed fuel and oxidant, and whose electrical output is combined. Fuel cell stacks either individually or combined into multi-stack modules are configured as part of fully self-contained power plants. The BOP includes all the components in a fuel cell power plant besides the electrochemical fuel cell stacks, consisting of fuel handling and clean-up equipment, air supply subsystem, heat recovery equipment, power conversion equipment, control equipment, etc. The design of an SOFC power system requires considerations for the cost of the components, operational transients and degradation of the fuel cells over a long period of time.
This presentation will discuss the recent advances in the development of the anode-supported planar SOFC technology, the scale-of the fuel cell stacks for commercial application, and the development of very unique market-entry SOFC-based power systems.
Biography: Hossein Ghezel-Ayagh is the Director of Solid State Energy Conversion Alliance (SECA) Program at FuelCell Energy (FCE). Hossein has a PhD degree from Illinois Institute of Technology in Chemical Engineering. He has been involved in research activities related to energy and electrochemical conversion devices. Hossein has participated in various aspects of fuel cell product development including materials research, electrocatalysis, stack design, and fuel processing. He has contributed to the design and development of components for phosphoric acid fuel cell (PAFC), PEM fuel cell, internal reforming carbonate fuel cell (MCFC) and SOFC systems. Currently, Hossein heads the Company’s SOFC and Electrochemical Membrane technology development activities. He directs a highly skilled team of scientists and engineers which are involved in all aspects of the SOFC technology development including cell components, stack scale-up, and systems design.
Faculty Host: Emily Ryan