Biogas powered fuel cell wins award, attracts attention from Sweden

Acumentrics Corporation, a leading developer of solid oxide fuel cells has won the 2007 New England Innovation Award from SBANE, the Smaller Business Alliance of New England. The company was one of 7 winners chosen from a pool of 171 applicants.

Acumentrics manufactures 5000-watt solid oxide fuel cell systems (SOFC) for power applications. It is also developing combined-heat-and-power units for the home market. Originally the company made power conditioners and backup for the military market. They acquired the fuel cell technology in 2000. Since then, they have increased the output of a single tube from 1 watt to 60 watts. Today they have over 30 fielded units.

One of their key innovations was making ceramic fuel cell technology shatter resistant. It is shatter resistant because of its shape - it is a tube, not a thin sheet as most other fuel cell manufacturers have used - with a special composition of layers that prevents them from flaking off (diagram, click to enlarge). Solid oxide fuel cells must handle temperature swings from 20 to 800ºC. Many other solid oxide fuel cells crack when they are cycled on and off, because of thermal shock.

Carbon neutral biogas
Another highly important feature of the SOFC's is that they do not require hydrogen or the hydrogen economy - which is mired in controversy because it requires huge investments in production, distribution and storage technologies. Acumentrics' fuel cells instead run on biogas, natural gas, propane, ethanol, diesel, and biodiesel - because they can disassociate fuels in the tube, via in-situ reformation (diagram, click to enlarge). While their systems can run off hydrogen, too, customers prefer to work with logistic fuels that are more affordable. Acumentrics fuel cells consume half as much fuel as a comparable small-engine generator, per kW. The combination of carbon neutral biofuels with highly efficient fuel cells makes for what is probably the cleanest and most efficient power system currently in existence.

The fact that SOFC's can be fed carbon neutral biogas instead of hydrogen has attracted the attention of the EU, and more in particular of Germany and Sweden, world leaders in biogas production. In Germany, the fuel cell was used with biogas in a world's first, to cool a server farm. The biogas is supplied by Schmack Biogas, global technology leader in the sector (earlier post). Another SOFC project making use of biogas and delivering both heat and power in a highly efficient way was launched late last year by German company MTU CFC in the District of Böblingen in Leonberg (previous post).

The EU recently awarded a grant of €5.8 (US$7.5) to a European consortium undertaking a three-year project to develop Large Solid Oxide Fuel Cell-based (SOFC) power plants that run on a multitude of (bio)fuels. The project, "Towards a Large SOFC Power Plant" started on January 1, 2007, with a total budget of €11 (US$14.2) million (earlier post).

Last week, Acumentrics shipped another of its 5 kW fuel cell generators to the innovative GlashusEtt environmental information center in Stockholm, Sweden. This generator was purchased by ABB Corporate Research in Västerås, Sweden, together with 8 other Swedish companies and organizations (FMV, Fortum, GlashusEtt, JM, Morphic, SBC, the City of Stockholm and the Swedish Energy Agency). The purpose of the installation is to evaluate how the state-of-the-art solid oxide fuel cell (SOFC) works with the carbon neutral biofuel:
bioenergy :: biofuels :: energy :: sustainability :: biogas :: SOFC :: fuel cell :: CHP :: carbon neutral :: efficiency ::

"We are thrilled to see our units run on carbon-neutral biogas," said Gary Simon, CEO of Acumentrics. "People from all over the world come to observe Hammarby Sjöstad’s clever environmental system. And our ability to run directly off biogas makes our fuel cells extremely practical. While we can run on hydrogen, too, it is great to offer compatibility with logistical, affordable fuels. The renewable aspect is a huge bonus."

Stockholm has developed a new, eco-friendly, waterfront district called Hammarby Sjöstad which is slated to house some 25,000 residents. The district features solar cells, green roofs, foot paths, environmentally benign building materials, vacuum-assisted refuse collection, and a wastewater treatment plant that produces biogas for the district.

The wastewater treatment plant produces high quality, 97% methane biogas that is piped into apartments for heating and cooking. This same biogas is piped to the Acumentrics fuel cell system. Acumentrics’ solid oxide fuel cells disassociate fuels inside the cell, via in-situ reformation. They run directly from the biogas, without the need for complex pre-processing (reforming) of the fuel. The result is an elegant power system with fewer parts.

At present the electricity produced by the fuel cell is put to a load bank, but grid-tie ability is slated for later this year. Acumentrics’ fuel cells have the unique ability to follow loads. Output can be adjusted up or down with no harm to the cells. The company believes this is the first real-world solid oxide fuel cell installation that runs on biogas.

The GlashusEtt is Hammarby Sjöstad’s environmental information center. Knowledge is disseminated via study trips, exhibitions, and demonstrations of new environmental technology. Acumentrics’ fuel cell system is located on the third floor.

Acumentrics’ fuel cells can be built inexpensively, which was independently confirmed by the US Department of Energy’s SECA program in its rigorous tests for cost, reliability, durability, efficiency, and start-stop cycling. Today, all of the manufacturing is done in Westwood, MA. The company starts with ceramic powders which are formed into tubular cells, and finishes with fully-enclosed power systems complete with computer controls. In winning the SBANE award, Acumentrics joins an illustrious list that includes companies like Genzyme, Stonyfield Farm, The Mathworks, and iRobot.

Hyper efficiency and carbon negativity
In Europe, biogas is being developed on a large scale for the production of fuels for stationary power generation (to be used in natural gas plants), as well as for the transport sector (earlier post). It is being fed into the natural gas grid on a large scale (previous post) or in dedicated pipelines supplying cities (see here), while some are creating real biorefineries around it that deliver green specialty chemicals, fuels and power (earlier post). The green gas can be made by the anaerobic fermentation of biomass, either obtained from dedicated energy crops (such as specially bred grass species or biogas maize), or from industrial, municipal or agricultural waste-streams.

Of all biofuels, biogas delivers most energy per hectare of crops. It is also the least carbon intensive production path, with some biogas pathways actually delivering carbon negative bioenergy (earlier post). In Germany, some project the potential for biogas to be so high that it might replace all natural gas imports from Russia (see here).

Meanwhile, new fuel cells are being developed that do not require hydrogen to function, but that work on all common types of biofuels, from biomass-based syngas to ethanol and biogas. The latter fuel path is far more feasible for large-scale power generation than hydrogen, the production of which is inefficient, very costly and not very clean (if derived from fossil fuels; in case the hydrogen is made from biogenic processes and biomass, it is renewable and carbon-neutral, but currently, biohydrogen production is not very efficient).

The combination of the efficiency of the SOFC fuel cells - which is far higher than power plants using combustion engines or turbines - and the low carbon footprint and efficiency of biogas production based on organic waste, may probably be the cleanest and most efficient large-scale energy system currently in operation anywhere.