Abstract: A modular direct reduction system for producing direct reduced iron (DRI) includes a reformer system which receives a flow of feed gas and which discharges a flow of reducing gas, the reformer system including a plurality of separate reformer modules connected together and wherein each reformer module includes a reformer vessel including an internal chamber, a reactor tube extending through the internal chamber of the reformer vessel and containing a catalyst configured to react with the feed gas received by the reactor tube to form the reducing gas, and a burner to burn a fuel gas to heat the reactor tube, and a furnace system connected to the reformer system and including a furnace having a first inlet which receives an iron ore, a second inlet which receives the reducing gas from the reformer system to form the DRI, and an outlet which discharges the DRI.