HEGEL Pablo Ezequiel
congresos y reuniones científicas
Thermodynamic modeling for process design, simulation and optimization in the production of biodiesel
Puerto Varas
Conferencia; IX Iberoamerican Conference on Phase Equilibria and Fluid Properties for Process Design; 2012
Institución organizadora:
In the last decade the production of soybean and sunflower oil has greatly increased worldwide. Together with it, the market of the oil refining by-products, phospholipids sludge (wet gum) and distillates of the deodorizer (DDEO), is rapidly changing. Particularly, the lecithin content of soy oil is quite high; therefore, large volumes of sludge are being produced. This sludge contains approximately 25% oil and 25% of lecithin. Since it also has almost 50% water, its nutritional value for animal fed is low if used without further processing. In this work we propose to perform the direct hydrolysis of phospholipids and oil enclosed in the wet gum. A series of experiments was performed to determine the effect of temperature (523 K to 563 K) and water to lipids mass ratio (7 to 24 m/m). In all the studies a complete conversion of lipids was observed. After the separation of solid substrate and volatile compounds, the reaction products soluble in hexane (upper 70 wt.% of the initial lipids) have a concentration of fatty acids greater than 50 wt%.The biodiesel production industry requires thermodynamic models able to correlate and predict the phase equilibria of the mixtures present along the process. Moreover, very high accuracy is required in some due to their sensitiveness to the components distributions, like the glycerol washing out unit, in order to achieve an appropriate design, simulation and optimization of the production and purification sections. In this work, the Group Contribution Equation of State (GCA-EoS) is applied to model several systems of importance in this field. The mixtures evaluated can be highly non-ideal, especially in the last purification steps where polar compounds are infinitely diluted in biodiesel. Experimental VLE and LLE data were satisfactorily correlated and predicted with a single set of interaction parameters, using a simplified version of the association contribution of the model. In this way GCA-EoS can be used for the whole process with a faster convergence of simulated units in comparison with the case of considering the rigorous association model. Furthermore, considering that GCA-EoS is a group contribution model, biodiesel production from different raw material, i.e soy, palm or canola oil, can be predicted without requiring new parameters adjustment.