Tri-Generation of Hydrogen, Heat and Power From a High Temperature Fuel Cell

Tri-Generation of Hydrogen, Heat, and Power from a
High Temperature Fuel Cell

Jack Brouwer*, Roxana Bekemohammadi, Pere Margalef

National Fuel Cell Research Center
University of California, Irvine

*corresponding author: jb@nfcrc.uci.edu; 949-338-5953 <>Abstract

The current project involves collaborative development and application of a high temperature fuel cell (HTFC) tri-generation system for the first time in the world.  In addition, the current tri-generation system is fueled with anaerobic digester gas that is renewably produced at a wastewater treatment plant.  The National Fuel Cell Research Center is working with Air Products and Chemicals, Inc. and FuelCell Energy to demonstrate HTFC tri-generation at the Orange County Sanitation District facilities in Fountain Valley, California. The current project is successfully demonstrating local highly efficient production of power, heat and hydrogen from a renewable fuel.  The system under test at OCSD can produce up to 125 kg of hydrogen per day, which is sufficient to fuel a fleet of approximately 200 – 300 vehicles.  In addition to having zero emissions, fuel cell vehicles are substantially more efficient than internal combustion engine vehicles and can displace, as a result, more petroleum than the equivalent amount of hydrogen (on an energy basis).  As a result, the current project will displace between 300 and 360 gallons of gasoline per day. <>Introduction

The National Fuel Cell Research Center (NFCRC) of the University of California, Irvine (UCI) has led research, development and demonstration projects focused upon High-Temperature Fuel Cell systems development. In parallel, the NFCRC is engaged in studies of the hydrogen economy from the generation to the utilization of hydrogen. In recent years, the NFCRC has led the development of a novel and attractive strategy for hydrogen fueling that includes: (1) the conceptualization of the “Energy Station,” and (2) HTFC systems for tri-generating hydrogen, heat and power.

One of the most exciting recent developments in integrated energy conversion systems is the concept of poly-generation or tri-generation of power, heat and hydrogen from a high temperature fuel cell. The concept deserves attention and investment because of the significant efficiency improvement, emissions reductions, and resource conservation potential it portends.  In recent years attention to this concept has become especially pronounced with the demonstration of the concept as operated on anaerobic digester gas at the OCSD.  This abstract briefly summarizes the evolution of the concept and the basic features of the concept to aid in understanding its history and potential. <>Benefits of the High Temperature Fuel Cell Hydrogen Co-Production Concept

The basic concept is to capture and purify hydrogen produced by a high temperature fuel cell for use as a fuel in fuel cell automobiles. The processes of fuel processing and high temperature fuel cell electrochemical production of heat and power are synergistically integrated as shown in  REF _Ref323118790 \h Figure 1 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003300320033003100310038003700390030000000 , for example, for a molten carbonate fuel cell.  Thus, a high temperature fuel cell can be used to co-produce electricity for a building and hydrogen for a local refueling station, avoiding the energy and environmental impacts of hydrogen transport and distribution.  Key technical and strategic benefits of this concept are:

(1)   Local hydrogen production avoids the negative energy and environmental impacts of traditional hydrogen transport, distribution and dispensing means,

(2)   HTFC can theoretically produce up to three times as much hydrogen as is required for electricity production using heat and steam that it naturally produces and would otherwise have to reject,

(3)   If all of the reformate/hydrogen stream is sent through the fuel cell its efficiency increases,

(4)   Co-generated hydrogen is a much higher value product than thermal energy,

(5)   Generation of varying relative amounts of hydrogen and electricity allows additional operator control to increase value added, and reduce operating costs,

(6)   Additional hydrogen production provides needed cooling to the fuel cell,

(7)   A cooler fuel cell can operate with less excess air, which reduces the main system parasitic load (air blower power) to additionally improve efficiency,

(8)   Stationary fuel cell systems are already designed to include integrated natural gas reformation technology, and

(9)   Stationary high temperature fuel cell systems with reformers have proven near-zero emissions and high fuel-to-electricity efficiency.

Figure  SEQ Figure \* ARABIC 1. Tri-generation concept as applied to an internally reforming molten carbonate fuel cell <>History of the Tri-Generation Concept

Some of the earliest presentations of HTFC tri-generation were published in 2001 [e.g., Brouwer et al., 2001].  From 2001 to 2003, the tri-generation concept was advanced through: (a) cycle conceptualization, (b) thermodynamic cycle analyses, and (c) dynamic systems analyses.  In 2003, NFCRC worked to develop a collaboration between Air Products and Chemicals Inc. (APCI) and FuelCell Energy (FCE), which led to successful analyses and development of tri-generation with funding support from the U.S. DOE.

NFCRC presented Tri-Generation research results at several technical conferences in 2005 [Leal and Brouwer, 2005a; 2005b; 2005c].  In addition, NFCRC leadership worked with California Governor Arnold Schwarzenegger to develop the California Hydrogen Highway Blueprint Plan, into which they introduced the “Energy Station” concept which includes HTFC tri-generation. [Samuelsen, 2005] In the analyses that accompanied the Blueprint Plan, tri-generation was found to be the most efficient means to produce, deliver, and dispense hydrogen to vehicles.

In 2006, NFCRC researchers published “A Thermodynamic Analysis of Electricity and Hydrogen Co-Production using a Solid Oxide Fuel Cell” [Leal and Brouwer, 2006].  From 2007 to 2009, APCI worked with FCE to advance the concept with U.S. DOE funding support.  The NFCRC independently advanced the technology by developing dynamic simulation capabilities. [Shaffer et al., 2008; Shaffer and Brouwer, 2009]  NFCRC continued active tri-generation research from 2009 to present, which included completing a dissertation [Margalef, 2010], writing a book chapter [Brouwer and Margalef, 2012], and publishing several papers that analyze tri-generation [Margalef et al., 2011; Shaffer and Brouwer, 2012; Margalef et al., 2012].

From 2011-present, APCI, FCE and NFCRC have partnered to experimentally and theoretically advance tri-generation technology with funding from the DOE and California Air Resources Board.  The tri-generation system that has been installed and that is undergoing testing is shown in  REF _Ref323119018 \h Figure 2 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003300320033003100310039003000310038000000 . The research being accomplished is proving the tri-generation concept, measuring gas clean-up, hydrogen separation technology performance, hydrogen purity, and overall efficiencies for producing the co-products from anaerobic digester gas, compressing and dispensing hydrogen to on-road fuel cell vehicles in California.  In addition, the current effort is providing valuable data for verifying thermodynamic and dynamic models of Tri-Generation technology. 

Figure  SEQ Figure \* ARABIC 2.  Photograph of the Tri-Generation system at OCSD indicating major
system components <>References ADDIN EN.REFLIST

[1]   Brouwer, J., Samuelsen, G.S., Lee, S.W., and O'Connor, T., “Power Park Application of Fuel Cells and Advanced Energy Technologies,” Proceedings of the 92nd International District Energy Association Conference, Las Vegas, NV, May 14, 2001.

[2]   Samuelsen, G.S., “Energy Station Concept,” in California Hydrogen Blueprint Plan, Volume 2, 2005, available on-line at: http://www.hydrogenhighway.ca.gov/plan/reports/volume2_050505.pdf.

[3]   Leal, Elisângela Martins, and Jacob Brouwer, “A Thermodynamic Analysis of Electricity and Hydrogen Co-Production Using a Solid Oxide Fuel Cell,” Proceedings of the 3rd International Conference on Fuel Cell Science, Engineering and Technology, ASME Paper Number FC2005-74136, May, 2005a.

[4]   Leal, E.M., and Brouwer, J. “Thermodynamic Analysis of Production of Hydrogen Using High Temperature Fuel Cells,” 2005 ASME International Mechanical Engineering Congress and Expo, Paper Number IMECE2005-81912, November 5-11, 2005b.

[5]   Leal, E.M., and Brouwer, J., "Production of Hydrogen Using a High-Temperature Fuel Cell: Energy and Exergy Analysis," Proceedings of 18th International Congress of Mechanical Engineering, Paper Number COBEM05-1514, November 6-11, 2005c.

[6]   Leal, E.M., and Brouwer, J., A Thermodynamic Analysis of Electricity and Hydrogen Co-Production using a Solid Oxide Fuel Cell, ASME Journal of Fuel Cell Science and Technology, Volume 3, Issue 2, pp. 137-143, May, 2006.

[7]   Shaffer, Brendan P., Hunsuck, Michael, and Jacob Brouwer, “Quasi-3-D Dynamic Model of an Internally Reforming Planar Solid Oxide Fuel Cell for Hydrogen Co-Production,” Proceedings of the 6th International Conference on Fuel Cell Science, Engineering and Technology,  ASME Paper Number FC08-65193, May, 2008.

[8]   Shaffer, Brendan and Jacob Brouwer, “Dynamic model for understanding spatial temperature and species distributions in internal-reforming solid oxide fuel cells,” ASME Paper FuelCell2009-85095, June, 2009.

[9]   Margalef, Pere, "On the poly-generation of electricity, heat and hydrogen with high temperature fuel cells," PhD dissertation, University of California, Irvine 2010.

[10]     Margalef, Pere, Brown, Tim, Brouwer, Jacob, and Samuelsen, Scott, Short communication: Efficiency of poly-generating high temperature fuel cells, Journal of Power Sources, Volume 196, Issue 4, Pages 2055-2060, 15 February 2011.

[11]     Margalef, Pere, Brown, Tim, Brouwer, Jacob, Samuelsen, Scott, Conceptual design and configuration performance analyses of poly-generating high temperature fuel cells, International Journal of Hydrogen Energy, Volume 36, Issue 16, Pages 10044-10056, August, 2011.

[12]     Shaffer, Brendan and Jacob Brouwer, "Dynamic Model for Understanding Spatial Temperature and Species Distributions In Internal-Reforming Solid Oxide Fuel Cells," Journal of Fuel Cell Science and Technology, accepted for publication, March, 2012.

[13]     Margalef, Pere, Tim Brown, Jacob Brouwer, and Scott Samuelsen, Efficiency Comparison of Tri-generating HTFC to Conventional Hydrogen Production Technologies, International Journal of Hydrogen Energy, accepted for publication, March, 2012.

[14]     Brouwer, Jacob, and Pere Margalef, " Hydrogen Production by High Temperature Fuel Cells," in Encyclopedia of Sustainability Science and Technology, Robert A. Meyers, ed., Springer, 2012.