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Is there a Future for Fuel Cells in Exploration and Production of Oil and Gas?

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Why Fuel Cells ?

Fuel cells are in focus as the future energy conversion tool in the transportation sector, for stationary power production as well as for power supply to portable electronics. Large development programmes are under way in Europe, the US, Japan and Asia.

A fuel cell converts the chemical energy in the fuel to electricity and heat through an electrochemical reaction. For simplicity, a fuel cell can be viewed as a battery that provides direct current (DC)-power and heat as long as fuel is supplied to the cell.

The energy conversion takes place in the fuel cell stack consisting of cell plates and electron-conducting interconnect plates stacked on top of each other. Each cell plate consists of three layers – a cathode (air side), an electrolyte and an anode (fuel side). The chemical reactions taking place at the anode or cathode depends on the fuel and type of cell. One possible cathode reaction is:

O₂ + 4e- = 2O^2-

The corresponding anode reaction may be

2H₂ + 2O²- = 2H₂O + 4e-

Several fuel cell technologies are being developed, each named after the electrolyte facilitating the diffusion of ions, e.g. H+ or O^2-, through the electrolyte.

Some fuel cells, e.g. the proton exchange membrane (PEM) cell, require close to pure hydrogen for reliable operation over time whilst others, like the Direct Methanol Fuel Cell (DMFC), can operate on methanol and the Solid Oxide Fuel Cell (SOFC) can be fuelled by natural gas.

No moving parts are involved in the energy conversion process and thus valves and air blowers comprise the only moving parts in a fuel cell system. Furthermore, fuel cell systems can offer from moderate to very high electrical efficiencies and nitrogen oxide (NO_x) emissions are typically in the range of 1parts per million volume (ppmv) or lower. Thus, fuel cell technology paves the way for silent, energy-efficient and low-emission power production.

Exploration and production (E&P) of oil and gas is energy-consuming, and emissions to the atmosphere resulting from consumption of energy is recognised as a major global pollution problem. Accordingly, every major oil and gas company, as any other major energy consumer, have an obligation to pursue new solutions facilitating reduced future operational emissions. Fuel cell technology may well be a part of such future solutions.

State of the Art

As yet, the only commercially available fuel cell is the phosphoric acid fuel cell (PAFC). Prototype PEM- and DMFC-based systems are emerging. The former may substitute the combustion engine in future passenger vehicles and the latter is expected to start replacing batteries in hand-held computers, mobile phones or personal computers (PCs) in just a few years.

For stationary power production, the SOFC is of particular interest due to its high electrical efficiency, fuel diversity capabilities and potential for mass production at a competitive cost. For example, SOFC-systems can be operated on pre-reformed natural gas, gasified biomass or gasified coal. SOFCs operate at high temperatures providing high quality waste heat allowing favourable integration with endothermic processes resulting in potentially very high thermal efficiencies. This technology is still on demonstration level and considerable efforts are being made both in Europe and particularly in the US to develop commercial SOFC-based power supply systems. In the following, some future SOFC applications of relevance to oil and gas E&P are described.

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