Biogas performance

On Testa farm biogas in used in two Fiat Totem combined heat and power units. The performance of the Totem is reported in table V. 

Hybrid membranes have been reported to successfully increase the performance of polymeric materials in different gas separation applications, such as the production of enriched oxygen or nitrogen streams, biogas and natural gas upgrading, and CO2 capture in postcombustion. 

An alternative to the use of H2 as fuel is methanol, which is a liquid fuel and easy to handle. This can be directly transformed to electrical current in a DMFC (direct methanol fuel cell). The DMFC allows a simple system design. However, presently achieved performance data of DMFC is not satisfactory and material costs are too high. As another alternative, methanol or hydrocarbons (e.g. natural gas, biogas) can be transformed to hydrogen on board the electric vehicle by a reformation reaction. This allows use of the H2-PEFC cell, which has a higher level of development. The reformate feed gas may contain up to 2.5% carbon monoxide (CO) by volume, which can be reduced to about 50ppm CO using a selective oxidizer (Wilkinson et al. [1997]). 

Moller, H. B., Nielsen, A. M., Nakakubo, R., Olsen, H. J. (2007). Process performance of biogas digesters incorporating pre-separated manure. Livestock Science, II2, 217—223. 

The paper presents an analytical model of the Biogas Tower Reactor, a new type of reactor for anaerobic waste water treatment. This model is developed on the basis of biochemical assumptions and knowledge of the reactors hydrodynamics. The dynamical model helps to understand the process in detail and to evaluate the performance of the process. A simplified linearised model will be derived in order to facilitate the design of the controllers. 

As already mentioned, MCFCs can be used with many different gases, such as natural gas, coal gas, biogas, and landfill gas, but certain contaminants present in these fuels can be harmful to MCFC operation and cause degradation of performance and a reduction in cell life. 

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