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Papers by Andrew Dicks
Journal of Power Sources, 1996
In most cases hydrogen is the preferred fuel for use in the present generation of fuel cells bein... more In most cases hydrogen is the preferred fuel for use in the present generation of fuel cells being developed for commercial applications. O[ all the potential sources of hydrogen, natural gas offers many advantages, it is widely available, clean, and can be converted to hydrogen relatively easily. When catalytic steam reforming is used to generate hydrogen from natural gas, it is essential that sulfur compounds in the" natural gas are removed upstream of the reformer and various types of desulfurisation processes are available, in addition, the quality of fuji required for each type of fuel cell varies according to the anode material used, and the cell temperature. Low temperature cells will not tolera~, high concentrations of carbon monoxide, whereas the molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) anodes cont~.~', nickel on which it is possible to electrochemically oxidise carbon monoxide directly. The ability to internally reform fuel gas is a feature ~ ~ the MCFC and SOFC. lntemal reforming can give benefits in terms of increased electrical efficiency owing to the reduction in the requi,.~ d cell cooling and therefore parasitic system losses. Direct electrocatalysis of hydrocarbon oxidation has been the elusive goal of fuel t'cll developers over many years and recent laboratory results are encouraging. This paper reviews the principal methods of converting natural ~. ts into hydrogen, namely catalytic steam reforming, autothermic reforming, pyrolysis and partial oxidation; it reviews currently availa~~e purification techniques and discusses some recent advances in internal reforming and the direct use of natural gas in fuel cells.
Journal of Power Sources, 2006
Carbon possesses unique electrical and structural properties that make it an ideal material for u... more Carbon possesses unique electrical and structural properties that make it an ideal material for use in fuel cell construction. In alkaline, phosphoric acid and proton-exchange membrane fuel cells (PEMFCs), carbon is used in fabricating the bipolar plate and the gas-diffusion layer. It can also act as a support for the active metal in the catalyst layer. Various forms of carbon -from graphite and carbon blacks to composite materials -have been chosen for fuel-cell components. The development of carbon nanotubes and the emergence of nanotechnology in recent years has therefore opened up new avenues of materials development for the low-temperature fuel cells, particularly the hydrogen PEMFC and the direct methanol PEMFC. Carbon nanotubes and aerogels are also being investigated for use as catalyst support, and this could lead to the production of more stable, high activity catalysts, with low platinum loadings (<0.1 mg cm −2 ) and therefore low cost. Carbon can also be used as a fuel in high-temperature fuel cells based on solid oxide, alkaline or molten carbonate technology. In the direct carbon fuel cell (DCFC), the energy of combustion of carbon is converted to electrical power with a thermodynamic efficiency close to 100%. The DCFC could therefore help to extend the use of fossil fuels for power generation as society moves towards a more sustainable energy future.
Catalysis Today, 1997
Steam reforming of hydrocarbons such as natural gas is an attractive method of producing the hydr... more Steam reforming of hydrocarbons such as natural gas is an attractive method of producing the hydrogen fuel gas required by fuel cells. It may be carried out external to the fuel cell or internally. The two types of fuel cell in which internal reforming is most appropriate are the molten carbonate (MCFC), operating at ca. 650°C and the solid oxide (SOFC) which currently operates above 800°C. At such temperatures, the heat liberated by the electrochemical reactions within the cell can be utilised by the endothermic steam reforming reaction. This paper reviews some of the catalytic aspects of internal reforming in these two types of cell. In the MCFC the major catalyst issue is that of long term activity in the presence of a corrosive alkaline environment produced by the cell's electrolyte. In Europe, this is being addressed by British Gas and others, in a programme part-funded by the European Commission. In this programme, potential catalysts for the direct internal reforming MCFC were evaluated in 'out-of-cell' tests. This has led to the demonstration of a 1 kW proof-of-concept DIR-MCFC stack and the start of a European 'Advanced DIR-MCFC' project. For the SOFC, it has been shown that state-of-the-art nickel cermet anodes can provide sufficient activity for steam reforming without the need for additional catalyst. However, anode degradation may occur when steam reforming is carried out for long periods. New anode materials could therefore offer significant benefits. 0 1997 Elsevier Science B.V.
Email (for orders and customer service enquiries): cs-books@wiley.co.uk Visit our Home Page on ww... more Email (for orders and customer service enquiries): cs-books@wiley.co.uk Visit our Home Page on www.wileyeurope.com or www.wiley.com All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any ...
Journal of Power Sources, 1996
In most cases hydrogen is the preferred fuel for use in the present generation of fuel cells bein... more In most cases hydrogen is the preferred fuel for use in the present generation of fuel cells being developed for commercial applications. O[ all the potential sources of hydrogen, natural gas offers many advantages, it is widely available, clean, and can be converted to hydrogen relatively easily. When catalytic steam reforming is used to generate hydrogen from natural gas, it is essential that sulfur compounds in the" natural gas are removed upstream of the reformer and various types of desulfurisation processes are available, in addition, the quality of fuji required for each type of fuel cell varies according to the anode material used, and the cell temperature. Low temperature cells will not tolera~, high concentrations of carbon monoxide, whereas the molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) anodes cont~.~', nickel on which it is possible to electrochemically oxidise carbon monoxide directly. The ability to internally reform fuel gas is a feature ~ ~ the MCFC and SOFC. lntemal reforming can give benefits in terms of increased electrical efficiency owing to the reduction in the requi,.~ d cell cooling and therefore parasitic system losses. Direct electrocatalysis of hydrocarbon oxidation has been the elusive goal of fuel t'cll developers over many years and recent laboratory results are encouraging. This paper reviews the principal methods of converting natural ~. ts into hydrogen, namely catalytic steam reforming, autothermic reforming, pyrolysis and partial oxidation; it reviews currently availa~~e purification techniques and discusses some recent advances in internal reforming and the direct use of natural gas in fuel cells.
Journal of Power Sources, 2006
Carbon possesses unique electrical and structural properties that make it an ideal material for u... more Carbon possesses unique electrical and structural properties that make it an ideal material for use in fuel cell construction. In alkaline, phosphoric acid and proton-exchange membrane fuel cells (PEMFCs), carbon is used in fabricating the bipolar plate and the gas-diffusion layer. It can also act as a support for the active metal in the catalyst layer. Various forms of carbon -from graphite and carbon blacks to composite materials -have been chosen for fuel-cell components. The development of carbon nanotubes and the emergence of nanotechnology in recent years has therefore opened up new avenues of materials development for the low-temperature fuel cells, particularly the hydrogen PEMFC and the direct methanol PEMFC. Carbon nanotubes and aerogels are also being investigated for use as catalyst support, and this could lead to the production of more stable, high activity catalysts, with low platinum loadings (<0.1 mg cm −2 ) and therefore low cost. Carbon can also be used as a fuel in high-temperature fuel cells based on solid oxide, alkaline or molten carbonate technology. In the direct carbon fuel cell (DCFC), the energy of combustion of carbon is converted to electrical power with a thermodynamic efficiency close to 100%. The DCFC could therefore help to extend the use of fossil fuels for power generation as society moves towards a more sustainable energy future.
Catalysis Today, 1997
Steam reforming of hydrocarbons such as natural gas is an attractive method of producing the hydr... more Steam reforming of hydrocarbons such as natural gas is an attractive method of producing the hydrogen fuel gas required by fuel cells. It may be carried out external to the fuel cell or internally. The two types of fuel cell in which internal reforming is most appropriate are the molten carbonate (MCFC), operating at ca. 650°C and the solid oxide (SOFC) which currently operates above 800°C. At such temperatures, the heat liberated by the electrochemical reactions within the cell can be utilised by the endothermic steam reforming reaction. This paper reviews some of the catalytic aspects of internal reforming in these two types of cell. In the MCFC the major catalyst issue is that of long term activity in the presence of a corrosive alkaline environment produced by the cell's electrolyte. In Europe, this is being addressed by British Gas and others, in a programme part-funded by the European Commission. In this programme, potential catalysts for the direct internal reforming MCFC were evaluated in 'out-of-cell' tests. This has led to the demonstration of a 1 kW proof-of-concept DIR-MCFC stack and the start of a European 'Advanced DIR-MCFC' project. For the SOFC, it has been shown that state-of-the-art nickel cermet anodes can provide sufficient activity for steam reforming without the need for additional catalyst. However, anode degradation may occur when steam reforming is carried out for long periods. New anode materials could therefore offer significant benefits. 0 1997 Elsevier Science B.V.
Email (for orders and customer service enquiries): cs-books@wiley.co.uk Visit our Home Page on ww... more Email (for orders and customer service enquiries): cs-books@wiley.co.uk Visit our Home Page on www.wileyeurope.com or www.wiley.com All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any ...