To provide an apparatus and a system suitable for continuously and stably producing hydrogen by taking advantage of a direction composition reaction of hydrocarbons as well as a method for separating a solid product.
Provided are a hydrogen producing apparatus using a nickel-based metal structure for the direct decomposition reaction of hydrocarbons and a discharging and recovering system comprising: a depressurization chamber communicating with a lower opening of the reaction chamber of hydrogen producing apparatus 1 via a ventilation hole; a first valve capable of opening and closing said ventilation hole; a collection box communicating with the depressurization chamber via a channel; a second valve capable of opening and closing said depressurization chamber; and a depressurization pump communicating with the collection box.