Helium star transform into a red giant after losing its hydrogen envelope in the future. Helium star A helium star or helium strong star is a class O or B star (blue), which has extraordinarily strong helium lines and weaker than normal hydrogen lines, indicating strong stellar winds and a mass loss of the outer envelope. "Extreme helium stars" (EHe) entirely lack hydrogen in their spectra. Previously, a "helium star" was a synonym for a B class star, but this usage is considered obsolete. A "helium star" is also a term for a hypothetical star that could occur if two helium white
Power-to-gas reaction, or biological methanation resulting in an extra energy conversion loss of 8%. The methane /SNG may then be fed into the natural gas grid or further converted in to LPG by synthesising SNG with partial reverse hydrogenation at high pressure and low temperature. LPG in turn can be converted into alkylate which is a premium gasoline blending stock because it has exceptional antiknock properties and gives clean burning. The third method uses the output gas of a wood gas generator or a biogas plant, after the biogas upgrader is mixed with the produced hydrogen from the electrolyzer, to upgrade