High pressure phase equilibria of supercritical alcohols with triglycerides, fatty esters and cosolvents

Supercritical fluid technology in biodiesel production

“…The reaction in continuous flow conditions yields above 98% conversion, with a single clear phase at moderate pressures (10-20 MPa), high temperatures (375-400°C), low methanol ratios (3:1-6:1), and short reaction times ( < 3 min). These results are in contrast with those reported by Hegel et al [58], Pereda et al [59], and Velez et al [60], who observed that high conversion can be obtained, in most cases, even when operating in the two-phase region. In this case, oil transesterification could mainly occur in the light supercritical phase, where the oil and the monoglycerides and diglycerides are partially soluble and the concentration of methanol is high.…”

Transesterification in Supercritical Conditions

“…3. The estimated critical pressure of soybean oil-methanol (Hegel et al, 2008) and palm kernel oil-methanol (Bunyakiat et al, 2006) mixtures.…”

“…In 2009, carbon dioxide was applied to supercritical transesterification with ethanol to reduce the operating conditions (Bertoldi et al, 2009). From 2007 to 2010, numerous additional studies, such as vapor-liquid equilibria of binary systems (Anitescu et al, 2008;Fang et al, 2008;Shimoyama et al, 2008;Shimoyama et al, 2009;Tang et al, 2006), phase behavior of the reaction mixture (Glišic & Skala, 2010;Hegel et al, 2008;Hegel et al, 2007), thermal stability of unsaturated fatty acids in supercritical methanol (Imahara et al, 2008) and process simulation and economic analysis (Busto et al, 2006;D'Ippolito et al, 2006;Deshpande et al, 2010;Diaz et al, 2009;van Kasteren & Nisworo, 2007) were reported, leading to a better understanding of the supercritical transesterification process.…”

“…Ethanol is also an interesting candidate because it can be industrially produced from renewable sources in many countries nowadays. However, other supercritical mediums, such as methyl acetate (Saka & Isayama, 2009) and dimethyl carbonate (Ilham & Saka, 2009;Tan et al, 2010b), have also (Hegel et al, 2008) and palm kernel oil-methanol (Bunyakiat et al, 2006) mixtures. …”

Phase equilibrium modeling of triglycerides in supercritical fluids

“…For phase equilibrium modeling of supercritical biodiesel, only transesterification of soybean oil in supercritical methanol with a 0021-9614/$ -see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jct.2010.10.020 propane co-solvent was reported with the use of the GCA-EOS model [9]. Recently, Oliveira et al [10] proposed a Cubic-Plus-Association EOS to predict the VLE of supercritical fatty acid ester in order to optimize the biodiesel production.…”