Propane is a fuel used for residential heating in the United States, and to a limited extent, has also been used as liquid transportation fuel. Although its production is currently petroleum-based, scientists from the Massachusetts Institute of Technology (MIT) have demonstrated that it could also be produced from biological raw material. Called the “C3 Bioenergy Process”, it utilizes “supercritical water” (water at high temperature and pressure), which facilitates the conversion of biological compounds to propane. According to MIT graduate student, Andrew Peterson, supercritical water becomes “non polar” (a chemical property of many organic compounds) during the reaction and mixes with the organic products. When the reaction approaches completion, the reaction is cooled down to room temperature and the propane “floats out” of the solution..