New Energy

Why are hydrogen fuel cells efficient alternative energy sources?

Fuel cell technology has existed since 1839, when electrochemical energy was first generated by combining hydrogen and oxygen, resulting in a by-product of water. Fuel cell systems have since been confined to niche applications such as space exploration, with the wider energy industry now exploring the potential of this exciting technology on a commercial scale. Several hydrogen oxygen fuel cell designs have been embraced to meet the growing demand for clean energy. These provide an excellent proposition for combined heat and power (CHP) projects but can be just as easily scaled down for mobile applications.

Fuel cell systems are strongly tipped as viable green energy sources of the future. The dwindling sustainability of traditional fossil fuels, and the relative simplicity of combining hydrogen and oxygen to create electricity and water, make this non-polluting alternative energy technology all the more attractive. Creating an efficient, reliable and safe clean energy source does, however, require considerable expertise. Not least in the control of fluids and gases involved in this ground-breaking technology. Bürkert has the knowledge and broad spectrum of products required to advance this technology to market.

How fuel cells work to convert hydrogen to electricity

Fuel cells work by converting electrochemical energy into electricity, heat and water. Each cell contains an anode and cathode electrode, as well as a connecting electrolyte. Gaseous hydrogen is supplied to the anode, while oxygen is fed to the cathode. The hydrogen fuel travelling across the electrolyte induces a positive and negative charge that generates the electrical current. When combined with oxygen, water forms as a by-product that subsequently requires draining. The main types of fuel cell offer advantages and challenges, but each requires a high degree of control infrastructure to operate efficiently and reliably. Something that Bürkert is equipped to provide, thanks to our comprehensive array of components, which we can also combine to develop cost-effective, bespoke system modules.

The importance of accurate gas control in fuel cell systems

For hydrogen oxygen fuel cells to adapt to changing loads, accurate gas control is essential. This relies on a thorough understanding of the hydrogen source and having a properly calibrated measurement system installed. Hydrogen-rich gas powered fuel cells require a controlled outlet for the non-hydrogen components to ensure continuous electricity production. Some fuel cell technology requires the oxygen and hydrogen to be mixed with steam in order to keep the proton exchange membrane humid. The temperature and load on the fuel cell determine the amount of steam required, which also affects the flow rate of the gases. Pressurised fuel cell systems demand careful pressure control to safeguard the integrity of the fuel cell. Bürkert offers a variety of proportional solenoids, pressure transducers and control valves for the precise control of pressures within the fuel cell.

Controlling aggressive ultra-pure water by-products in fuel cells for power generation

Humidifying gases via steam generation requires a control loop for ultra-pure water and a drain valve for the condensate. Without either of which the fuel cell would fill with water and become inoperable. Some fuel cell applications may favour passing the hydrogen through a water quench instead, which also requires close control of the water level. Any water created by the electrochemical reaction will also need to be drained. The corrosive nature of ultra-pure water means that careful consideration must be given to material specifications for valve components and seals, whatever the scenario. This is just one of many areas of expertise that Bürkert’s Systemhaus engineers can advise upon when developing fuel cell systems.

Supporting alternative energy sources of the future

Specialist and larger-scale applications for fuel cells have already been established and the technology is advancing. The focus is now on smaller, mobile installations, as well as the development of a hydrogen fuel station network.  Much of the research and development currently takes place on test bench models. The next step is to scale up these prototypes to develop commercially viable fuel cell systems. For producers aiming to develop new hydrogen oxygen fuel cell technologies, accurate and reliable control and monitoring of all the parameters will be critical. Bürkert draws on decades of experience and expertise to provide applicable gas mixing and metering units, flow control and measurement equipment, and additional safety shut-off valves. All of which can assist with the next evolutionary stages of this clean energy technology.

Bürkert products ideally suited to fuel cell system applications

Bürkert’s product range for fuel cell applications includes:

• Solenoid valves
• Flow sensors
• Pressure sensors
• Solenoid control valves
• Mass flow controllers
• Process valves
• Integrated peripheral modules

Bürkert products are suitable for the following fuel cell applications:

• Stationary power generators
• APUs (Auxiliary Power Units)
• Uninterruptible power supplies (UPS)
• Service vehicles
• Reformer systems
• PSA plants
• Hydrogen generators
• Fuel cell test benches

For more information about Bürkert’s capabilities in the fuel cell market, download our fuel cell brochure.