Eucalyptus pulp as an adsorbent for metal removal from biodiesel

• Eucalyptus pulp was employed as an adsorbent for metal removal from biodiesel.
• The treatment resulted in the removal of high amounts of Fe, Mn, and Cu from biodiesel.
• The use of cellulose fiber makes this process an environmentally friendly purification method.
• The regeneration of the cellulosic adsorbent is demonstrated.

This work reports the use of eucalyptus pulp as an adsorbent for metal removal from biodiesel. Fatty acid methyl esters produced from sunflower oil (SfMB) and recycled used cooking oil (RMB), which contained Fe, Mn, and Cu, were treated through filtration on a column filled with the cellulosic adsorbent, and washed with deionized water for comparison. The treatment with cellulose material resulted in the removal of 13–81%, 35–84%, and 40–74% of Fe, Mn, and Cu in biodiesels, while the water washing removed 4–40%, 10–47%, and 4–19%, respectively. In addition to the higher efficiency, the use of cellulose is a more environmentally friendly process than the purification with water, once the latter results in a considerable volume of effluent requiring treatment prior to disposal, besides the high consumption of water. Moreover, the regeneration of the cellulosic adsorbent is demonstrated.