A system for converting fuel may include a first moving bed reactor, a second reactor, and a non-mechanical valve. The first moving bed reactor may include at least one tapered section and multiple injection gas ports. The multiple injection gas ports may be configured to deliver a fuel to the first moving bed reactor. The first moving bed reactor may be configured to reduce an oxygen carrying material with a fuel by defining a countercurrent flowpath for the fuel relative to the oxygen carrying material. The second reactor may communicate with the first moving bed reactor and may be operable to receive an oxygen source. The second reactor may be configured to regenerate the reduced oxygen carrying material by oxidation.