text: In natural gas cyclic processes, a unit produces hot reducing gas, which is injected into the reactor. To ensure continuous operation of the unit converting natural gas into reducing gas, several tanks are operated in parallel and with a time lag.
  The best-known of this type is HYL I and its improved variant, HYL II. This is the oldest industrial direct gas reduction process, developed in Mexico in 1957 by the Hylsa company.