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PRODUÇÃO E ARMAZENAMENTO DE HIDROGÉNIO MOLECULAR A PARTIR DA HIDRÓLISE CATALISA...

Com esta sessão laboratorial pretende-se realizar ensaios, à temperatura controlada de 45ºC, de produção local (com simultâneo armazenamento) de hidrogénio molecular (H2) a partir da reacção de hidrólise catalisada de borohidreto de sódio (NaBH4). Pretende-se determinar a taxa de produção de hidrogénio, rendimento da reacção e tempos de indução. Os resultados obtidos deverão ser comparados, sempre que possível,...

Water handling challenge on hydrolysis of sodium borohydride in batch reactors

A study was undertaken in order to investigate the potential of hydrogen (H 2) generation by hydrolysis of solid sodium borohydride (NaBH 4) with stoichiometric amount of distilled water (from molar ratios H 2O/NaBH 4 (mol/mol) of 2 to 18), in the presence of a powder nickel-ruthenium based catalyst, reused more than 300 times. The experiments, performed in batch reactors with different free volumes and bottom ...

Batch sodium borohydride hydrolysis systems: Effect of sudden valve opening on ...

A study was undertaken in order to investigate the potential of hydrogen (H 2) generation by hydrolysis of sodium borohydride solution (10 wt% NaBH 4 and 7 wt% NaOH), in batch reactors, operating at moderate pressures (up to ∼1.2 MPa), in the presence of a powdered nickel-ruthenium based catalyst, reused between 311 and 316 times, to feed on-demand a proton exchange membrane fuel cell. A different approac...

Durability and reutilization capabilities of a Ni-Ru catalyst for the hydrolysi...

The study of catalyst durability and reutilization on catalyzed hydrolysis of sodium borohydride is essential from an application point of view. Few works on this topic are available in the literature. In the present work, a powder nickel-ruthenium based catalyst, unsupported, used in two different schemes of NaBH 4 hydrolysis (alkaline and alkali free hydrolysis), performed in batch reactors with different vol...

Alkali free hydrolysis of sodium borohydride for hydrogen generation under pres...

The present study is related with the production of hydrogen gas (H 2), at elevated pressures and with high gravimetric storage density, to supply a PEM fuel cell on-demand. To achieve this goal, solid sodium borohydride (NaBH4) was mixed with a proper amount of a powder reused nickel-ruthenium based catalyst (Ni-Ru based/NaBH4: 0.2 and 0.4 g/g; ≈150 times reused) inside the bottom of a batch reactor. The...

Effects of the addition of an organic polymer on the hydrolysis of sodium tetra...

An experimental study is presented both on the generation and storage of molecular hydrogen (H2) by small additions of an organic polymer - carboxymethyl cellulose (CMC) - to sodium borohydride (NaBH4) through the alkaline hydrolysis, in the presence of a powdered nickel-ruthenium based catalyst reused from 274 to 282 times. The experiments were performed at 45 °C in two batch reactors with internal volumes of ...

Artificial neural network model applied to a PEM fuel cell

Successive loadings of reactant in the hydrogen generation by hydrolysis of sod...

In this paper, for the first time, an experimental investigation is presented of five successive loadings of reactant alkaline solution of sodium borohydride (NaBH4) for hydrogen generation, using an improved nickel-based powder catalyst, under uncontrolled ambient conditions. The experiments were performed in two batch reactors with internal volumes of 0.646 l and of 0.369 l. The compressed hydrogen generated,...

Modelling Studies on Water Management in PEM Fuel Cells

Direct Methanol Fuel Cells operating at high methanol concentrations: modelling...