Density and Conversion in Biodiesel Production with Supercritical Methanol

• Published in: Industrial & engineering chemistry research Vol. 49; no. 16; pp. 7666 - 7670
• Main Authors: Velez, A, Hegel, P, Mabe, G, Brignole, E. A
• Format: Journal Article
• Language: English
• Published: American Chemical Society 18-08-2010
• Subjects: General Research
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie100670r

The densities of reacting mixtures of vegetable oils + methanol were measured by loading a closed vessel with a known amount of an oil/alcohol mixture of a given molar ratio. For each studied condition, the mixture was brought to a temperature at which the system became homogeneous. The isochoric (constant-volume) relation between temperature and pressure at this particular density and composition was recorded. In the temperature range of 550−630 K, a high conversion of the oil to the corresponding fatty esters and glycerin was obtained. The densities of sunflower oil with methanol for two different alcohol/oil ratios, namely, 40:1 and 25:1, were measured. Densities of coconut oil + methanol and methyl oleate + methanol mixtures were also measured. The effect of global density on conversion was studied at long reaction times (3−4 h). Strong evidence of the phase transitions of the reacting mixtures, from heterogeneous to homogeneous, was obtained from the experimental results.