Skip to main content

A collaborative project to build a 1 kW internal reforming molten carbonate fuel cell stack

Objective

Development of a 1kW internal reforming fuel cell unit. The main problem is the development of reformer catalysts (needed as the available heat is 600-650 C and the heat required for the reaction is 800 C) which are not poisoned by the corrosive carbonate atmosphere.
Catalyst deactivation:

Out-of-cell tests were performed in a tubular reactor to screen a number of potential catalysts as to their suitability for this particular application. From these tests, three catalysts were selected for in-cell tests on 100 cm{2} scale under severe conditions, meaning that the cell was loaded with only a very small amount of catalyst while nominally operated.

By comparing the deactivation rates in these tests, the best catalyst was then tested over 5000 hours under standard MCFC conditions in a 100 cm{2} cell at the end of the project. During that time, its deactivation was found to be negligible. It must be stressed, however, that this holds only for this kind of tests and for these operating times. For longer operation times or for cells eg loaded with a smaller amount of catalyst, deactivation may remain a problem, to which attention must be paid.

Carbonate poisoning:

This was considered to be the main cause of catalyst deactivation and dedicated experiments were performed to investigate the mechanism by which the carbonate was transported to the catalyst. In an MCFC stack, this was found to be either by creep or vapour phase transport. Both mechanisms and their relation with, among others, the catalyst substrate material have been investigated.

Stack testing:

In one of the two short stack experiments, the separator plates were loaded with a pulverized version of one of the selected catalysts (not the one selected for the long-duration test). However, the catalyst loading proved insufficient and the separator plates had to be modified to increase the catalyst loading by incorporating the catalyst in its usual form of 3.2x3.2 mm pellets. Finally, the 1 kW stack test was performed using the modified separator plates. It showed that the required power density (100 mW/cm{2}) could be attained.
Molten carbonate fuel cells (MCFC) operate at 650 C and can produce electricity from methane with 60% efficiency. They use reformers to transform methane into hydrogen for which temperatures of 800 C are required. The hydrogen is then fed into the fuel cell to produce electricity. In this project a concept will be developed where reforming takes place in the fuel cell using its waste heat. In this way the cost can be reduced as an expensive external reformer is not required; additional cost reductions are possible due to lower cooling requirements and the efficiency may be higher than for MCFC which use external reformers.

British Gas and CNR-TAE will develop suitable reformer catalysts. Components, cells up to 1000 cm2 and stacks up to 1 kW will be made by ECN. The testing of cells and stacks will be carried out by ECN.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

ENERGY RESEARCH CENTRE OF THE NETHERLANDS
Address
Westerduinweg 3
1755 ZG Petten
Netherlands

Participants (2)

British Gas plc
United Kingdom
Address
152 Grosvenor Road
SW1V 3JL London
NATIONAL RESEARCH COUNCIL OF ITALY
Italy
Address
Via Salita Santa Lucia Sopra Contesse 5
98126 Messina