Thermochemical processes are noted for their inherent difficulty in producing clean gas/vapor streams for fuel or chemical production, especially where catalytic upgrading of the gas stream is desired. The gas cleanup system can also account for a substantial portion of the overall capital cost. The carryover of char for example not only produces undesirable particulate contaminants, but also has been shown to cause secondary reactions that reduce yields of desired products. Some of these secondary reactions can produce sootthus further complicating the gas/vapor cleanup. Drawing on its eleven years experience designing, building, and operating fast pyrolysis systems, BLE has developed a combination continuous moving granular bed reactor and moving bed granular filter. The BLE reactor uses a design and geometry which allows moving bed reactor particles to serve as both a moving bed granular filter and as heat carriers to provide thermal energy for thermal treatment reactions. Thus the moving bed granular filter media and the heat carrier (HC) are one and the same and act to efficiently scrub solid particulate contaminants from the gas stream. The BLE combination reactor/filter design: Minimizes the carryover of char particulates in the gas/vapor stream, Can operate at atmospheric pressure or at elevated pressures, Minimizes the gas/vapor path length during gas cleanup, thus minimizing secondary reactions attributed to longer residence times and minimizing pressure drop attributed to gas cleanup operations, Reduces system capital and operating costs by combining reactor and gas cleanup operations into one unit operation, Simplifies the fast pyrolysis process and reduces the physical size of the overall system since: Additional, separate equipment for gas filtration is not needed, Additional controls are not needed, and additional methods to remove char from the reactor and recirculate the filter bed media are not needed. Allows the filtration process to be conducted at high temperatures without supplying additional energy, thus preventing the condensation of tar on gas cleanup equipment during the cleanup operation, is relatively easy to manufacture and use. The goals of this project are to use 3-D CAD modeling and cold-flow modeling and testing, followed by testing in our 10 lb/hr Process Development Unit (PDU) to: Develop scalable designs and, to the extent possible, optimize the performance of the combination moving bed granular reactor and filter (CMBGRF), to develop engineering information to facilitate scale up of the CMBGRF design.
