Experimental Study And Computer Simulation Of Steam Rectification

The separation of natural substances needs to be carried out at lowertemperature in order to avoid heat decomposition. Because of the disadvantages oftraditional steam distillation, the steam rectification with the existence of liquid waterwas proposed.In this paper, the hydrodynamics and mass transfer of steam rectification inpacked column was studied experimentally. A mathematical model based onequilibrium stage has been proposed to simulate the process, and the simulation resultagreed well with the experiment. The simulation result also showed that pressure dropand the composition of oil has less influence on the temperature than conventionaldistillation. The energy cost of steam rectification is considerably more than that ofconventional distillation.The experimental study showed that not only the temperature of steamrectification has a remarkable reduction compared with conventional distillation, butalso the vapor velocity of flooding point of steam rectification is much higher thanthat of conventional distillation, whereas, the maximum flow rate of oil is lower thanthat of conventional distillation in column of the same diameter. At the same vaporvelocity, the separation efficiency of steam rectification is higher than that ofconventional distillation, however, when they are compared at the same oil flow ratein column of the same diameter, the result is the opposite. In steam rectification, thepresence of liquid water can improve the mass transfer in the packed bed.