NOVELTY - Production of product(s) from syngas comprises gasifying a feedstock in the presence of an oxidant to provide a syngas comprising carbon dioxide, carbon monoxide, and hydrogen. At least a portion of the syngas is combusted to provide an exhaust gas. At least a portion of the exhaust gas is introduced to a channel having reaction zone(s) that are in indirect heat exchange with the exhaust gas. The reaction zones comprise catalyst-containing tubes. A reactant in at least one of the reaction zones is reacted to provide reactor products.    USE - The process is used for production of product(s), e.g. methanol, alkyl formates, dimethyl ether, ammonia, Fischer-Tropsch products, methane, and/or their derivatives. The Fischer-Tropsch products can be diesel fuels, kerosene, aviation fuels, naphtha, gasoline, detergents, waxes, lubricants, refinery/petrochemical feedstocks, other transportation fuels, synthetic crude oil, liquid fuels, alpha -olefins, and/or their derivatives.    ADVANTAGE - The recirculating solids can serve to rapidly heat the incoming feedstock that also minimizes tar formation. By operating at a nearly constant temperature, the reaction has a closer approach to equilibrium, which in turn requires less catalyst for the reaction. The dissipation of heat decreases the chances for hot spots in the reactor and prolongs catalyst life. The method can provide for leaks from duct-installed synthesis reactor tubes, steam coils, and process heat exchangers or boiler feed water (BFW) coils to pass into the exhaust gas and be controlled or vented. This minimizes any risk of cross-contamination between process streams. Since boiler feedwater at elevated pressure can be not used as a reactor-cooling medium in contact with the reactor tubes, there can be minimal risk of catalyst poisoning from the BFW in the event of a breach of a reactor tube wall.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a system for producing product(s) from syngas.    DESCRIPTION OF DRAWING(S) - The drawing is a sectional view of a gasifier.    Feedstock line (305)    Oxidants line (310)    Risers (325)    Disengagers (330, 340)    Syngas line (375)