Systems and methods for operating transport reactors are provided. The method can include fluidizing one or more particulates within a transport reactor. The one or more particulates can include one or more carbonaceous materials. The method can also include maintaining one or more pressure differentials between two or more points within the transport reactor using at least one integrally geared compression system. The at least one integrally geared compression system can include a bull gear, at least one pinion, and two or more compressors.