Fuel cells are widely regarded by researchers, industry and governments as a promising means of converting chemical energy directly into electricity with high efficiency and relatively low environmental impact. Among the various fuel cell technologies, proton exchange membrane fuel cell technology has advanced rapidly and is now being deployed commercially across a growing range of applications. Their broader deployment, however, remains constrained by the difficulty and cost of producing, storing and transporting high-purity hydrogen. Establishing a practical, reliable and economically viable fuel supply is therefore a central challenge for the fuel cell industry.

High-temperature proton exchange membrane fuel cells (HT-PEMFCs) generally operate between 130°C and 200°C. Like conventional low-temperature PEMFCs, which typically run at temperatures of no more than 80°C, they offer a flexible system configuration and high power density. Their higher operating temperature provides greater tolerance to certain contaminants in the fuel stream, particularly carbon monoxide in hydrogen-rich reformate.

This greater tolerance can simplify balance-of-plant requirements by reducing the need for extensive fuel purification and thermal management. Depending on the system configuration, fuel quality and operating conditions, these characteristics may also improve overall system efficiency and help reduce operating complexity and costs. Rather than depending exclusively on high-purity hydrogen, these systems can use industrial by-product hydrogen or hydrogen-rich reformate produced from fuels such as methanol. Electricity and useful heat can therefore be generated simultaneously, improving overall fuel utilisation.

HT-PEMFCs may help address several long-standing challenges associated with conventional hydrogen energy systems. These include the high cost of hydrogen purification, the technical demands of storage and transportation, the need for dedicated refuelling infrastructure, and the complexity of safety management. Producing and consuming hydrogen at the point of use can reduce certain storage, transportation and refuelling requirements. This approach may be particularly suitable for combined heat and power applications in which both electricity and recoverable heat can be utilised locally.

The range of potential uses is broad. In both civilian and defence settings, HT-PEMFC systems could supply onboard power for road vehicles and marine vessels, serve as emergency backup units, or support mobile and stationary power generation. They may also be suitable for distributed combined heat and power systems, particularly in applications where both electricity and useful thermal energy are required close to the point of consumption.

Methanol-reforming combined heat and power systems may also offer a relatively low-carbon route to distributed energy generation. The carbon intensity of electricity produced by a methanol-reforming HT-PEMFC system is estimated at approximately 0.62 g of CO₂per kWh. The remaining carbon dioxide can be absorbed in a calcium hydroxide solution and converted into calcium carbonate, which can then be used as a raw material in cement production. Another option is to process the captured CO₂into dry ice for use in the food and cold-chain sectors.

For projects producing tens of thousands of tonnes of CO₂, carbon capture, utilisation and storage (CCUS) technologies can be incorporated to recover the emitted carbon dioxide for use in green methanol production. This approach can establish a circular carbon pathway, supporting both large-scale greenhouse gas emission reductions and the lower-carbon utilisation of fossil energy resources.