Simulation by Aspen Plus on desolventizing of crude oil in soybean protein extracting process with reverse micelles

Abstract: Compared with other traditional methods, the disadvantages of high production costs and pollution prevention were overcome in the soy-protein extraction process by reverse micelles. Soybean crude oil, containing organic solvent, can be extracted together with soybean protein by reverse micelles. It is necessary to control the purity of the organic solvent that is recycled, as well as the purity of the soybean crude oil in the circulating production process. The Aspen Plus 11.1 software is used for simulating the desolventizing of crude oil in the soy-protein extraction process by reverse micelles, which is aimed at recycling the organic solvent. This work aims to study continuous and circulating spirit distillation by computational simulation, presenting some strategies of process control to regulate the purity of the solvent and the soybean oil. With the modular analysis function of Aspen Plus, the purity of the oil and solvent, the stage number of distillation column, and the heat load of the reboiler and the condenser were analyzed. A generalized model (based on the NRTL model) for estimation of activity coefficients is applied to the simulation of the extraction process. The equilibrium stage model based on the RADFRAC module of Aspen Plus is employed for the steady-state simulation of the improved process flowsheet, and therefore rigorous simulations allow the appropriate operating conditions to be established in the separating process. It is shown in the results that the reflux ratio of the vacuum distillation was 0.352, the distillate flow was 10.348 kg/h, and the purity of the oil and solvent can be 98.9% and 99.7% respectively, while the actual heat loads of the reboiler and the condenser were 1398.824 W and -1626.226 W, respectively. According to the sensitivity analysis, the concentration of oil and solvent grew respectively with the number of stages, and the optimal number of stages was seven. The cost was analyzed based on simulation calculations, in which the annual cost savings was￥1,272,000. As an alternative to control the purity of solvent and soybean oil, the spirit distillation unit was highly efficient in the case of low contamination and production costs. Moreover, the reflux ratio and product flow rate have an important influence on the purity of spirit composition. The key parameters were provided for unit operations separating organic solvent from soybean oil. The technical key points for the industrialized installation design were discussed to provide reliable data for enlarged desolventizing devices in the industrial field.