Combined hydrogen storage - compression system for the filling of high pressure hydrogen tanks

The present relates to a combined hydrogen storage-compression unit suitable for the filling of high-pressure (350 bar and beyond) hydrogen vessels. It comprises a containment vessel filled with a hydrogen storage alloy, a heating system, a cooling system and a thermal management system. The instant invention shall be connected directly to the hydrogen supply (e.g. an electrolyser) on one side and to the end consumer on the other side. Moreover, it offers the possibility for intermediate storage of at least one time the maximal quantity of hydrogen that is to be supplied at high pressure in a single step.

Hydrogen Storage in Formic Acid – Amine Adducts

Matthias Beller, Gabor Laurenczy

Formic acid, containing 4.4 wt% of hydrogen, is a non-toxic liquid at ambient temperature and therefore an ideal candidate as potential hydrogen storage material. Formic acid can be generated via catalytic hydrogenation of CO2 or bicarbonate in the presence of an amine with suitable ruthenium catalysts. In addition selective dehydrogenation of formic acid amine adducts can be carried out at ambient temperatures with either ruthenium phosphine catalyst systems as well as iron-based catalysts. In detail we obtained with the RuCl2(benzene)/dppe catalyst system a remarkable TON of 260,000 at room temperature. Moreover applying Fe-3(CO)(12) together with tribenzylphosphine and 2,2':6',2 ''-terpyridine under visible light irradiation a TON of 1266 was obtained, which is the highest activity known to date for selective dehydrogenation of formic acid applying non-precious metal catalysts.

Schweizerische Chemische Gesellschaft2011

Hydrogen storage and delivery: immobilization of a highly active homogeneous catalyst for the decomposition of formic acid to hydrogen and carbon dioxide

Paul Joseph Dyson, Weijia Gan, Gabor Laurenczy

The homogeneous catalytic system, based on water-soluble ruthenium(II)– TPPTS catalyst (TPPTS = meta-trisulfonated triphenylphosphine), selectively decomposes HCOOH into H2 and CO2 in aqueous solution. Although this reaction results in only two gas products, heterogeneous catalysts could be advantageous for recycling, especially for dilute formic acid solutions, or for mobile, portable applications. Several approaches have been used to immobilize/solidify the homogeneous ruthenium– TPPTS catalyst based on ion exchange, coordination and physical absorption. The activity of the various heterogeneous catalysts for the decomposition of formic acid has been determined. These heterogenized catalysts offer the advantage of easy catalyst separation/recycling in dilute formic acid, or for mobile, portable applications.

Springer Netherlands2009

Propelling the hydrogen economy: from chemical storage and delivery to utilization in biomass conversion

Lu Chen

Since H2 is a non-polluting, inexhaustible, efficient, and sustainable energy carrier, it has been forecast to become one of the major carriers of energy in the future and is also essential in the production of feedstock chemicals derived from renewable carbon sources. Initially, a Ru(II) catalyst with meta-trisulfonated triphenylphosphine ligands was shown to be a versatile homogeneous catalyst for the reversible dehydrogenation/hydrogenation of N-heterocycles. N-heterocyclic liquid organic hydrogen carrier compounds are attractive H2 storage and delivery compounds. Hydrogen is also essential in reductive fragmentation of lignin, an abundant biomass source that can be cleaved under reductive conditions to produce value-added renewable aromatic platform chemicals. In native lignin most of the units are linked by C-O bonds. Therefore, selective catalytic cleavage of the C-O bonds plays a pivotal role in maximizing the efficiency of the process while maintaining desirable functionality. A pseudo-homogeneous catalytic system consisting of in situ generated platinum nanoparticles dispersed in ionic liquids was used for upgrading high oxygen content bio-oil through hydrodeoxygenation. To improve further the stability of the catalyst, well-defined rhodium nanoparticles dispersed in sub-micrometer size carbon hollow spheres were prepared, which were able to hydrogenate lignin derived products under mild conditions. Confinement of active rhodium nanoparticles within a carbon shell, prevents the intact lignin polymer from entering and interacting with the catalyst. Thus, this catalysts was used to demonstrate that solvolysis leads to fractionation and fragmentation of lignin, with the internal catalysts hydrogenating any reactive fragments generated. An atomically dispersed catalyst, comprising single Pt atoms on Ni nanoparticles supported on carbon, were used in depolymerization of lignin and showed enhanced activity on selective C-O bonds cleavage.

EPFL2021

Propelling the hydrogen economy: from chemical storage and delivery to utilization in biomass conversion

Lu Chen

EPFL2021