In this paper an ethanol reformer based on catalytic steam reforming with a catalytic honeycomb loaded with RhPd/CeO2 and palladium separation membranes with an area of 30.4 cm2 has been used to generate a pure hydrogen stream of up to 100 ml/min to feed a PEM fuel cell with an active area of 5 cm2. The fuel reformer behavior has been extensively studied under different temperature, ethanol–water flow rate and gas pressure at a fixed S/C ratio of 1.6 (molar). The hydrogen yield has been controlled by acting upon the ethanol–water fuel flow and gas pressure.\ud
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A mathematical model of the ethanol reformer has been developed and an adaptive and predictive control has been implemented on a real time system to take account of its nonlinear behavior. With this control the response time of the reformer can be reduced by a factor of 7 down to 8 s.\ud
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The improved dynamics of the controlled reformer match better the quickly changing hydrogen demands of fuel cells. They reached a magnitude where costly hydrogen buffers between the reformer and the fuel cell can be omitted and an electric buffer at the output of the fuel cell is sufficient.Postprint (published version
In late June 2007, the Epidemiological Surveillance Network in Castilla y León, northern Spain, reported a series of cases in a rural area in the province of Palencia and in the provincial capital city of León, labelled as “fever of unknown origin”. Subsequent epidemiological investigation confirmed an outbreak of tularaemia.
Abstract-This paper addresses the control of an experimental PEM fuel cell system. The fuel cell station is composed by an ElectroChem R 7-cell stack with Nafion 115 R membrane electrodes assemblies (MEAs) and the auxiliary equipment. The control problem is focussed on the air supply in the cathode. The main objectives are to regulate the stack voltage and the cathode oxygen excess ratio. The manipulated variables are the compressor motor voltage and the command current of a proportional valve located at the cathode outlet. A linear and dynamic model at a given operational point is obtained via step tests, which is used in the context of a centralized multivariable Dynamic Matrix Control (DMC).
Official rules and literature concerning the practice of inventories in the management projects or revisions of resin production forests are revised in this paper. Several recommendations on the same subject are also made.
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