Torrefaction Processing for Human Solid Waste Management

The proposed approach will make it technically feasible to process human fecal waste and wet mixed waste streams and produce additional water and other useful products in space which will benefit long term space travel, such as an extended Lunar stay or a mission to Mars and Asteroids/Phobos. It is beneficial to NASA in also allowing for solid waste sterilization and stabilization, planetary protection, in-situ resource utilization (ISRU) and/or production of chemical feedstocks and carbon materials. In particular, the solid residue has several potential applications in space. These include production of activated carbon, a nutrient-rich substrate for plant growth, as a filler for polymers and composites, radiation shielding, carbon/hydrogen storage, and fuel gas (CH4, CO, H2) production. In addition to its primary purpose to process fecal waste, torrefaction could potentially be beneficial for other types of wastes, including food wastes, wipes, clothing, and brine.

The goal of the Phase I project was to demonstrate that torrefaction processing of human fecal waste could be advantageous in a spacecraft or habitat environment. In the near term, the fecal waste processing component of the technology would also have applications to fecal resource recovery and/or sterilization/stabilization problems in remote areas such as underdeveloped countries, arctic regions, military operations, oil production platforms, rural areas, farms, submarines, ships, etc., analogous to the uses for NASA technology developed for water purification. In the long term, the technology could be modified and integrated with widespread terrestrial efforts using fecal and related organic solid waste streams to produce biochar for soil amendments, soil remediation, polymer fillers, composite materials, carbon sequestration, solid waste disposal and resource recovery. More »