One exception to note: If the food's sitting in an environment where the temperature is over 90Â°F, the USDA says the food should only be left out for one hour, so keep an eye on the clock if you're serving food on a hot day!
Estimated cost of hydrogen per kilogram in a variety of scenarios. With all of this in mind, here are the cost estimates per kilogram (which each include $1.25 for taxes): Hydrogen from natural gas (produced via steam reforming at fueling station). $4 â $5 per kilogram of hydrogen.
Industrially, hydrogen gas is made using two methods, usually one after the other. In the first reaction, called steam reforming, methane is reacted with water to form hydrogen gas and carbon monoxide.ndustrially, hydrogen gas is made using two methods, usually one after the other. In the first reaction, called steam reforming, methane is reacted with water to form hydrogen gas and carbon monoxide.