Abstract: The invention relates to an integrated process for continuous production of liquid hydrogen, comprising (a) producing gaseous hydrogen by electrolysis; and (b) liquefying said gaseous hydrogen in a hydrogen liquefaction unit, which liquefaction unit is powered by energy essentially from renewable sources; and, (c) when additional power is needed, using electrical energy generated in a process in which electrical energy and hydrogen are co-generated by an integrated electrolysis process comprising: (d) electrolysing a metal salt or mixture of metal salts and water into the corresponding metal or metals, acid or acids, and oxygen (electricity storage phase), and (e) producing gaseous hydrogen and recovering electricity in a regeneration reaction of the metal (s) and acid(s) of step (d) (regeneration phase); wherein at least part of the gaseous hydrogen generated in step (e) is used in step (b) of the process.

Abstract: A methane content of a bottom sample comprising methane hydrate crystals is determined by:—taking a core sample (5) from a bottom sediment (3) in a deepwater area;—storing the core sample (5) in a storage chamber (4);—lifting the storage chamber (4) to a predetermined waterdepth (BGHZ=Base of Gas Hydrate stability Zone) at which any methane hydrate crystals in the core sample (5) dissociate into water and methane; and—measuring an amount of methane released by the lifted core sample (5).

Abstract: A method for producing hydrocarbons wherein hydrates are excavated from the sea bottom and mixed into a transportable slurry, the slurry being pumped to a support vessel, using near sea bottom positive displacement hydraulic pumps, where the hydrates are converted into a hydrocarbon containing stream, with excavation tailings being pumped down to hydraulic motors to drive the hydraulic pumps.

Abstract: A methane content of a bottom sample comprising methane hydrate crystals is determined by:—taking a core sample (5) from a bottom sediment (3) in a deepwater area;—storing the core sample (5) in a storage chamber (4);—lifting the storage chamber (4) to a predetermined waterdepth (BGHZ=Base of Gas Hydrate stability Zone) at which any methane hydrate crystals in the core sample (5) dissociate into water and methane; and—measuring an amount of methane released by the lifted core sample (5).

Abstract: A method for producing hydrocarbons wherein hydrates are excavated from the sea bottom and mixed into a transportable slurry, the slurry being pumped to a support vessel, using near sea bottom positive displacement hydraulic pumps, where the hydrates are converted into a hydrocarbon containing stream, with excavation tailings being pumped down to hydraulic motors to drive the hydraulic pumps.