A chemical-looping system utilizes oxygen-carrier particles to produce syngas from carbonaceous fuels. The system provides a circuitous flow path for the oxygen-carrier particles, which are used to partially oxidize the fuel to produce syngas. The circuitous flow path can proceed through a plurality of unit operations, including a reducer, a conversion reactor, an oxidizer, and a combustor. The conversion reactor is designed to partially oxidize carbonaceous fuel in co-current flow with the oxygen-carrier particles to produce syngas. In embodiments including an oxidizer, the oxidizer is designed to at partially re-oxidize the carrier particles, yielding hydrogen that can be mixed with partially oxidized products from the conversion reactor to adjust syngas quality. The combustor can be used to fully oxidize the carrier particles traveling in a closed loop. Reactions carried out in the combustor are highly exothermic and yield thermal energy that is absorbed by the carrier particles. The absorbed energy is used at other parts of the process, including the conversion reactor, to drive endothermic reactions. In this manner the system can be operated autothermally or nearly so. Methods of producing syngas are also disclosed.

Disclosed herein is a reaction process system comprising: a reactor system configured to support an endothermic process of a feedstock: wherein the reactor system comprises: a reaction chamber with an internal region arranged to support the endothermic reaction of the feedstock; a heating system that is at least partially within the internal region of the reaction chamber; the heating system comprises a plurality of heating reactors; each heating reactor comprises walls that separate an internal region of the heating reactor from the rest of the internal region of the reaction chamber; each heating reactor comprises an oxygen carrier material in the internal region of the heating reactor; each heating reactor is arranged to support a reduction reaction between the oxygen carrier material and a fuel in the internal region of the heating reactor; and each heating reactor is arranged to support an oxidation reaction between the oxygen carrier material and oxygen in the internal region of the heating reactor; one or more heat exchangers arranged to generate the steam by heating water with heat recovered in dependence on one or more fluid flows out of the reactor system; and when applicable, a steam supply conduit arranged to supply at least some of the generated steam to the reactor system.

The torrefaction unit 1 comprises at least one multiple hearth furnace 2 which is heated by a heat transfer fluid 16 comprising hot water taken from a water space 21 of a steam drum 11. The heat transfer fluid 16 is guided through a water circuit 20 to a heating system 19 of the at least one multiple hearth furnace 2. This means the multiple hearth furnace 2 is heated to a torrefaction temperature indirectly by the use of hot water as heat transfer fluid 16. This is environmentally advantageous. The torrefaction gas 3 created by the torrefaction of material comprising biomass such as municipal solid waste is preferably partially oxidized in a partial oxidation reactor 23 for creating syngas. Preferably, a part of the thermal energy of the syngas is used in an evaporator 9 and/or a superheater 13 to heat water and/or steam and/or to evaporate water. The evaporated water is preferably guided to a steam space 22 of the steam drum 11 and can, thus, be used to heat the heat transfer fluid 16. The partial oxidation reactor 23 and the temperature of the heat transfer fluid 16 can be controlled independently allowing to one single partial oxidation reactor 23 for at least two multiple hearth furnaces 2.