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Hydrogen processing of magnet scrap
Hydrogen processing of magnet scrap (HPMS) is a recycling method that uses hydrogen gas to turn sintered rare earth magnets like NdFeB into demagnetized powder for new magnets.
Hydrogen production
Hydrogen production, also called hydrogen generation, is the industrial manufacture of hydrogen gas, mostly from fossil fuels, with 97 million tonnes produced globally in 2023.
Hydrogen Production Model
The hydrogen production model is a combined experimental and analytical representation, built by JAERI and JAEA, of a steam methane reforming plant coupled directly to Japan's HTTR high-temperature gas-cooled reactor.
Hydrogen recovery from refinery purge gas
Hydrogen recovery from refinery purge gas is the capture and purification of unreacted hydrogen from refinery purge streams, mainly by pressure swing adsorption, membranes, or cryogenic separation.
Hydrogen safety
Hydrogen safety is the set of properties, engineering practices, and codes for handling hydrogen fuel safely, addressing its wide flammability range, low ignition energy, and embrittlement of metals.
Hydrogen Shot
Hydrogen Shot is a US Department of Energy initiative launched in June 2021 to cut the cost of clean hydrogen production 80%, to $1 per kilogram in a decade.
Hydrogen society
A hydrogen society is an energy system using hydrogen as a major energy carrier, a goal Japan has pursued with policy since its 2017 strategy.
Hydrogen storage
Hydrogen storage is the keeping of hydrogen as high-pressure gas, cryogenic liquid, solid-state compounds, or underground salt caverns until needed as fuel, a key enabling technology for transportation and stationary power.
Hydrogen storage alloy
A hydrogen storage alloy is an intermetallic compound or alloy that reversibly absorbs hydrogen gas as a metal hydride, used in Ni–MH batteries and stationary storage.
Hydrogen sulfide splitting
Hydrogen sulfide splitting is the decomposition of hydrogen sulfide (H₂S) into hydrogen and sulfur, pursued as a refinery waste treatment and a low-energy route to clean hydrogen.
Hydrogen Systems (company)
Hydrogen Systems is the name of several unrelated companies, including a Belgian electrolyser patent assignee, a Russian Norilsk Nickel fuel-cell venture, and a Saudi distributor.
Hydrogen train
A hydrogen train is a rail vehicle using a fuel cell to turn onboard hydrogen into electricity, emitting only water; the first entered service in Germany in 2018.
Hydrogen trapping
Hydrogen trapping is the binding of dissolved hydrogen atoms to defects and interfaces in a metal lattice, such as dislocations and grain boundaries, slowing hydrogen diffusion and altering embrittlement risk.
Hydrogen valley
A hydrogen valley is a geographically defined region where hydrogen production, storage, distribution, and local end use grow together as one integrated regional value chain.
Hydrogen vehicle
A hydrogen vehicle is a motor vehicle that uses hydrogen as its energy source, most commonly a fuel cell electric vehicle whose exhaust is only water vapor.
Hydrogen water chemistry
Hydrogen water chemistry (HWC) is a boiling water reactor practice, developed in the United States in the late 1970s, that injects hydrogen into feedwater to stop stress corrosion cracking.
Hydrogen-powered aircraft
A hydrogen-powered aircraft, also known as a hydrogen plane, is an aircraft that burns hydrogen in gas turbines or converts it to electricity in fuel cells, emitting no carbon dioxide.
Hydroid, Inc.
Hydroid, Inc. is an American manufacturer of autonomous underwater vehicles, best known for the REMUS family, founded in 2001 and acquired by HII in 2020.
Hydrokinetic turbine
A hydrokinetic turbine, also called a kinetic or free-flow turbine, generates electricity directly from moving water such as river or tidal currents without a dam, like an underwater wind turbine.
Hydrometallurgical lithium-ion battery recycling
Hydrometallurgical lithium-ion battery recycling recovers metals from spent lithium-ion batteries by leaching cathode material in acid and separating lithium, nickel, and cobalt, recovering over 95% of lithium.
Hydropeaking
Hydropeaking is the rapid fluctuation of river flow and water level downstream of hydropower plants, caused by turbine releases timed to meet peak electricity demand.
Hydrophilization
Hydrophilization is a surface treatment that converts a material's outermost layer into a water-attracting state, improving adhesion, printability, and biocompatibility; main methods include wet-chemical oxidation, flame treatment, and plasma.
Hydrophone
A hydrophone is an underwater microphone, an electroacoustic transducer that converts pressure fluctuations in water into electrical signals, first developed during World War I to detect German U-boats.
Hydropneumatic suspension
Hydropneumatic suspension is an automotive suspension using gas as the spring and hydraulic fluid as the damper, invented by Paul Magès at Citroën and first shown in 1954.
Hydropower
Hydropower, also called water power, is a renewable source of electricity that converts the energy of flowing or falling water into electricity using turbines and dams.
Hydropower Sustainability Standard
The Hydropower Sustainability Standard (HSS) is a global certification scheme defining environmental, social, governance, and climate performance requirements for hydropower projects, launched in September 2021 and managed by the Hydropower Sustainability Alliance.
HydroPRS
HydroPRS, also marketed as Hydro-PRT, is a chemical recycling process by UK company Mura Technology that uses supercritical water to convert mixed plastic waste into hydrocarbon feedstocks for new plastics.
Hydropyrolysis
Hydropyrolysis is pyrolysis carried out under pressurized hydrogen, giving a stable, low-oxygen oil; catalytic hydropyrolysis converts biomass and plastics directly into hydrocarbon fuels, cutting greenhouse gas emissions.
Hydros Robotic System
The Hydros Robotic System is an FDA-cleared surgical robot by PROCEPT BioRobotics of San Jose, California that delivers Aquablation therapy, a heat-free, AI-planned waterjet treatment for an enlarged prostate.
Hydrostatic bearing
A hydrostatic bearing, also called an externally pressurized bearing, is a fluid-film bearing in which a pump supplies the pressure that keeps the surfaces separated, even at zero speed.