Complementary blending of meadowfoam seed oil methyl esters with biodiesel prepared from soybean and waste cooking oils to enhance fuel properties†

The complementary blending of cold-pressed meadowfoam seed oil methyl esters (MFME) with soybean and waste cooking oil methyl esters (SME and WCME) was investigated. MFME prepared from cold-pressed meadowfoam oil exhibited an exceptionally high induction period (IP) of 66.2 h whereas SME and WCME yielded considerably lower values of 5.9 and 4.5 h, respectively. The kinematic viscosities (KVs) of SME and WCME were within the prescribed ranges in the biodiesel standards (ASTMD6751 and EN 14214) but MFME was not due to its content of unique longer-chain fatty acids. Furthermore, the iodine value (IV) of SME was in excess of the maximum limit specified in EN 14214 whereas MFME and WCME were not. Lastly, the cold flow properties of MFME were superior to those of SME and WCME. Complementary blends of MFME-SME and MFME-WCME ameliorated deficiencies of the individual fuels. Blends containing 20–30 vol % MFME in WCME provided IPs, KVs and IVs within the limits prescribed in both ASTM D6751 and EN 14214. With respect to MFME-SME blends, those containing 30–50% MFME complied with the specifications of both biodiesel standards. In addition, highly linear correlations between percentage of MFME and fuel properties were established. Furthermore, the influence of storage for 90 days on fuel properties of the blends was determined.