Olive oil wastewater could be newest biofuel feedstock

In France, scientists at Mulhouse Institute of Materials Science are finding ways to use olive oil wastewater, a harmful pollutant, for useful products, like biofuel and fertilizer. They mixed wastewater created from olive oil production with cypress sawdust, another waste product that is common in the Mediterranean, where 97 percent of the world’s olive oil is produced. The mixture was dried and water collected as it evaporated. The water was clean and used for crop irrigation and the dried material was exposed to high temperatures without oxygen (pyrolysis) which caused it to decompose into combustible gas and charcoal pellets. The gas was then collected and condensed into a biobased oil that could be used as a heat source and the charcoal used as crop fertilizer. In field tests, they found that vegetation grown with the charcoal biofertilizer had improved plant growth than those without the biofertilizer.