The Study Of The Separation Of N-Alkanes And ?-alkenes From Oil Product Of Fischer-Tropsch Synthesis

Fischer-tropsch synthesis is one of the important methods of coal liquefaction.So it is very important to study the separation of n-alkanes and?-alkenes of fischer-tropsch synthesis products.In this paper,based on the C₁₀0 as raw material,solvent selection,determination of vapor-liquid equilibrium data,simulating calculation and lab-scale experiment were conducted for the extractive distillation of1-decene and n-decane.At first,the solvents were selected by the extraction solvent qualitative rule.Inspect the relative volatility of the original system through the vapor-liquid equilibrium.The results showed that dimethyl phthalate was the suitable solvent.Two element interaction parameters are needed in the simulation of extractive distillation process,and there is no report in the literature.So the vapor-liquid equilibrium data of the two groups of three elements were determined by the improved Rose reactor.The experimental data were obtained by the thermodynamic consistency test,and the model parameters of the NRTL equation were obtained.Then,the extractive distillation of 1-decene and n-decane with dimethyl phthalate as solvent was simulated with process software.Effect of the theoretical plate number,reflux ratio,solvent ratio,solvent feed stage and feed stage on the mass fraction of n-decane in top product were studied by using single factor experimental design.The results showed that the extractive distillation column,when the theoretical plate number was 55,reflux ratio was 2,solvent ratio was 8,solvent feed stage was 4 and feed stage was 25,the mass fraction of n-decane was 99.1%?wt?;the solvent recovery column,when the theoretical plate number was 27,reflux ratio was 2,the mass fraction of 1-decene was 99.2%?wt?,At the same time,the solvent in the bottom can be recyled.At last,the extractive distillation to separate n-decane and 1-decene by using dimethyl phthalate were studied in a batch extractive tower.The variation of the mass concentration of the top product with time was investigated under the optimal operation condition R=2 and S/F=8.The mass fraction of n-decane in top product was95.96%?wt?and 1-decene was 99%?wt?.The results showed that dimethyl phthalate played a good effect in the separation of 1-decene and n-decane.