METHOD FOR PURIFICATION OF BIODIESEL
The invention pertains to a method for purifying crude biodiesel, wherein said crude biodiesel is contacted with a clay material, said clay material having: a surface area of more than 120 m2/g; a total pore volume of more than 0.35 ml/g; a silicon content, calculated as Siθ2, of at least 60 wt.-%.
1 . Method for purifying crude biodiesel, wherein said crude biodiesel is contacted with a clay material, said clay material having:
a surface area of more than 120 m2/g;
a total pore volume of more than 0.35 ml/g;
a silicon content, calculated as Si0 2 , of at least 60 wt.-%.
2 . Method according to claim 1 , wherein the clay material contains more than 10% of amorphous material as determined by quantitative X-ray diffraction analysis of the mineral phases of the clay material.
3 . Method according to claim 1 , wherein the clay material has an aluminium content, calculated as Al 2 0 3 , of less than 15 wt.-%.
4 . Method according to claim 1 , wherein the clay material has a sediment volume in water after 1 h of less than 15 ml/2 g.
5 . Method according to claim 1 , wherein the clay material has a cation exchange capacity of more than 40 meq/100 g.
6 . Method according to claim 1 , wherein the clay material contains magnesium, calculated as MgO, in an amount of less than 7 wt.-%.
7 . Method according to claim 1 , wherein the crude biodiesel contains more than 0.2 wt.-% glycerol.
8 . Method according to claim 1 , wherein no water washing step is performed on the crude biodiesel.
9 . Method according to claim 1 , wherein the biodiesel is obtained by alcoholysis of a triglyceride.