Turning human excrement into biofuel

team of researchers from Israel’s Ben Gurion University of the Negev (BGU) has demonstrated, for the first time, a technique for converting human excrement into hydrochar—a safe, renewable biomass fuel that resembles charcoal—as well as a nutrient-rich fertilizer. According to the team, this process could potentially address two major issues that affect many less-affluent countries—poor sanitation and growing energy needs.In a pilot study published in the Journal of Cleaner Production, the researchers described how they used a technique known as “hydrothermal carbonization” to heat raw solid human waste in a special “pressure cooker” to three different temperatures (180, 210 and 240 degrees Celsius) for periods of either 30, 60 or 120 minutes.This sterilizes the human waste and dries it out, creating a solid coal-like substance known as hydrochar, which can be used for household cooking and heating. In addition, a nutrient-rich liquid is produced that could be used as a fertilizer. Last year, the BGU researchers carried out similar research using poultry excrement.