In some cases, gases such as oxygen, nitrogen, syngas and hydrogen are produced by industrial gases companies that are focused on these products. In other cases, the user of the industrial gas, such as a steel works, methanol plant, ammonia producer, oil refinery or chemicals plant will produce the industrial gases that they require for themselves. This is known as ‘captive production’ and takes place within the battery limits of the plant. In essence the same technologies are used to produce the industrial gases and the same gas analysis requirements exist. The only difference is that you are either making the gas for yourself, or buying it from an outsourced industrial gas provider.