Operational Data for a Full Scale Prototype Torrefaction Processing Unit (TPU) for Spacecraft
This paper describes work on the development and testing of a full scale prototype Torrefaction Processing Unit (TPU). The TPU can be used to sterilize human solid waste and produce a stable, relatively odor-free solid product that can be more easily stored or recycled, and also to simultaneously recover moisture. This TPU is designed to be compatible with the Universal Waste Management System (UWMS), now under development by NASA. A stand-alone TPU could be used to treat the waste canister from the UWMS, thus allowing the waste canister to be reused and significantly reducing the number of canisters required on board. The main components are the stainless steel canister, heating jacket, heat bridge aluminum bottom plate, stainless steel top plate, temperature probe, air-cooled water vapor pre-chiller, thermoelectric water vapor condenser, particle filtration unit, gas sensor array, and data acquisition system. The gas sensors measure carbon dioxide (CO2), carbon monoxide (CO), and hydrogen sulfide (H2S). A nitrogen carrier gas flow (~ 1 LPM) is controlled by a mass flow controller. The carrier gas flow is not essential to the torrefaction process, but is convenient for the gas analysis measurements. The canister is lined with a PTFE bag for easy removal of the torrefied material at the end of the processing step. It was tested with about 20 bagged samples of simulated or actual solid waste material and representative amounts of the associated paper products. The data include processing time, the solid, liquid and gaseous product yields, and the total energy consumption. Experimental data, along with modeling using the COMSOL Multiphysics package, were used to further optimize and finalize the TPU design.
Mark Wojtowicz, Advanced Fuel Research (AFR), Inc., USA
Joseph Cosgrove, Advanced Fuel Research (AFR), Inc., USA
Thomas Stapleton, United Technologies Aerospace Systems (UTAS), USA
Jeffrey Lee, National Aeronautics and Space Administration (NASA), USA
ICES304: Physio-Chemical Life Support - Waste Management Systems - Technology and Process Development
The 49th International Conference on Environmental Systems was held in Boston, Massachusetts, USA on 07 July 2019 through 11 July 2019.