Fuel Cell Design ENCH 340 Spring, 2005 UTC

Technical and Economic Aspects of a 25 kW Fuel Cell Chris Boudreaux Jim Henry, P.E. Wayne Johnson Nick Reinhardt

Technical and Economic Aspects of a 25 kW Fuel Cell Investigate the design of --a 25 kW Fuel Cell --Coproduce Hydrogen --Grid parallel --Solid Oxide Electrolyte Chemical and Thermodynamic Aspects Our Capabilities

Outline Introduction to the project Flowsheet Development Equipment Design Economics

Introduction Overall Reaction Methane + Air --> Electricity + Hydrogen + Heat

Introduction Pressure Swing Absorption Fuel Cell Reformer Gas Hydrogen Electricity Air Heat SynGas POC

Fuel Cell-Chemistry SynGas Air O+O+ O+O+ H2H2 H2OH2O CO CO 2 POC O 2 N 2 “Air” Solid Oxide Electrolyte Is porous to O + H2H2 + CO

Fuel Cell-Electricity SynGas Air O+O+ O+O+ H2H2 H2OH2O CO CO 2 POC O 2 N 2 “Air” Electrons Load

Fuel Cell-Challenges SynGas Air O+O+ O+O+ H2H2 H2OH2O CO CO 2 POC O 2 N 2 “Air” H2H2 + CO Hot SynGas Hot Air Recover H 2 Recover Heat

Flowsheet Development

Equipment Design

Economics

Fuel Cell Heat. Objective Develop and demonstrate a 25 kW, grid parallel, solid oxide fuel cell system that coproduces hydrogen., the installation be configured to simultaneously and efficiently produce hydrogen from a commercial natural gas feedstream in addition to electricity. This ability to produce both hydrogen and electricity at the point of use provides an early and economical pathway to hydrogen production.. Ceramic processing and challenges in the design and manufacturing process of SOFCs will be addressed. The amount of hydrogen that the unit produces may be controlled by the adjusting the natural gas flow at steady power production (i.e., adjusting the fuel utilization). A nominal production rate of 25 kg of hydrogen per day falls within the expected upper and lower utilization limits for 25 kW electricity production. The system produces a hydrogen-rich exhaust stream that will be purified using a Pressure Swing Absorption (PSA) unit. The hydrogen flow and purity are interdependent. It is expected that purity >98% is achievable for flows of 2-3 kg/day. Critical impurities, such as CO and CO2 will be measured. It is not clear that this size system makes sense for commercial production. We are looking at a 25 kW module as a building block for commercial production to begin in The size of the 25 kW module is estimated to be smaller than a 5 ft cube. The cost of early commercial systems is expected to be <$10K/kW