What do you need to know about hydrogen?
Hydrogen, along with other renewables and natural gas, is playing an increasingly important role in the clean energy landscape. Hydrogen is found in a variety of substances, including light, water, air, plants and animals, but is often combined with other chemicals, the best-known combination being with oxygen to make water.
What is hydrogen and what are its benefits?
Historically, hydrogen gas has been used as a component of rocket fuel, as well as in gas turbines to generate electricity or for combustion in internal combustion engines to generate power. In the oil and gas industry, excess hydrogen from catalytic reforming of naphtha was used as fuel for other unit operations.
Hydrogen is a colorless, odorless and tasteless gas that is lighter than air. Since it is lighter than air, this means that it rises higher than our atmosphere, which means that it does not occur naturally, but must be produced. This is done by separating it from other elements and collecting the vapor. Electrolysis is completed by taking a liquid, usually water, and separating it from the chemicals in it. In water, the hydrogen and oxygen molecules separate, leaving two hydrogen bonds and one oxygen bond. The hydrogen atoms form a gas that is captured and stored until needed, while the oxygen atoms are released into the air as they are no longer used. The hydrogen produced has no harmful effects on the environment, which makes many experts believe it is the future.
Why hydrogen is seen as a cleaner future.
In order to generate energy, fuel, which is a chemical substance, is burned. The process usually means breaking chemical bonds and combining them with oxygen. Traditionally, methane gas has been the gas of choice - 85% of homes and 40% of electricity in the UK depend on gas. Methane was seen as a cleaner gas compared to coal, but when it is burned, carbon dioxide is produced as a waste product, contributing to climate change. Hydrogen gas, when burned, produces only water vapor as a waste product, which is already a natural resource.
The difference between blue hydrogen and green hydrogen.
Blue hydrogen is produced from non-renewable energy sources by two methods: steam or autothermal. Steam reforming of methane is the most common for mass production of hydrogen. This method uses a reformer that produces steam at high temperature and pressure, which is combined with methane and a nickel catalyst to produce hydrogen and carbon monoxide. Autothermal reforming uses the same process, but with oxygen and carbon dioxide. Both methods produce carbon as a byproduct.
Green hydrogen is produced using electricity to power an electrolyzer that separates hydrogen from water molecules, producing oxygen as a byproduct. This also allows excess electricity to be used for electrolysis to produce hydrogen gas that can be stored for the future.
The properties that hydrogen possesses have set a precedent for the future of energy. The U.K. government has recognized it as the path to a greener lifestyle and has set a goal for a thriving hydrogen economy by 2030. Japan, South Korea and China are on track to make significant progress in the development of hydrogen technology, and their 2030 goals match those set by the U.K.
PRINCIPLE OF OPERATION OF FUEL CELLS
The design of fuel cells is very simple: each consists of two electrodes and a polymer membrane. The semi-permeable membrane allows only the diffusion of protons, allowing hydrogen cations into the cathode space, which react with oxide anions. Electrons from the anode are diverted to an external electrical circuit, generating the current needed to power equipment. Fuel cells are maintenance-free and not subject to wear and tear.
DESCRIPTION OF THE PROCESS
The fuel cell consists of two electrodes and a membrane that lets only positively charged hydrogen molecules pass through. Hydrogen protons combine with oxygen atoms to form water. The electrons are redirected into an electrical circuit, creating a current that sets the car in motion.