Swedish Energy Agency grants PowerCell $1.4M loan for the development of next-generation fuel cell APU system
The Swedish Energy Agency has granted fuel cell technology company PowerCell, a spinout from the Volvo Group (earlier post), a loan of SEK 10 million (US$1.385 million) for the development of the next generation PowerPac APU (auxiliary power unit) system, which converts diesel fuel into electricity via a system comprising a catalytic reformer and fuel cells. The next-generation unit covers a larger power range up to 25 kW and maintains the same tolerance towards CO and reformate gas as the present platform.
The PowerCell system comprises three modules: the fuel reformer; the fuel cell stack; and the power electronics. PowerCell selected an Auto Thermal Reactor (ATR) technology to evaporate (not combust) the diesel and extract hydrogen-rich gas with gas purity well within the limits of what a low temperature PEM fuel cell can support in terms of CO.
Fuel reformers mix a fuel with steam and/or air and let the mixture pass a catalytic surface. The reactants are then converted into hydrogen, carbon dioxide, steam and carbon monoxide, with a reaction temperature of more than 400 ˚C. To create an efficient reactor, the catalyst is distributed over a porous support.
To reform diesel on-board in a transport application, the process needs to be self-sustained on heat for the reaction. This is done by combining catalytic oxidation (creates heat) of diesel and steam reforming (requires heat) of diesel. By balancing these two reactions, a nearly heat-source-independent solution is created, called auto-thermal reforming (ATR).
By avoiding combustion, no NOx or particle matters are created. Downstream, sulfur is trapped and carbon monoxide is cleaned up while the hydrogen content is enriched. Further, since no combustion takes place, the noise level is reduced (<60 dBA). The conversion is also efficient (>30%, after DC/DC), making fuel cost low compared to traditional diesel-fueled APU solutions.
PowerCell developed its own proprietary PEM fuel cell, reducing parasitic losses and increasing system robustness. This is achieved through special gas inlets and flow field design.
The reformer module is combined with the fuel cell module by balancing the heat and water in the system. A key property of the PowerCell fuel cell system using diesel is that it does not require any additional water for the reforming process as long as the ambient air temperature is below 40°C.
The next generation of PowerPac focuses on an increased life-span of the stack and the reformer and a reduced production cost. Within the project, a number of prototypes of PowerPac will be produced for field testing before the product is fully developed and ready for sale in Sweden and internationally.
We expect that the interest for the next generation of PowerPac to be huge within the telecommunications and transport sectors globally, as these industries need to significantly reduce their operating costs. PowerPac can help achieve this with a power solution that is clean, durable and compatible with increasingly stringent environmental laws.—Magnus Henell, CEO of PowerCell Sweden