Separation Technology Of The By-Product In Water Of Fischer-Tropsch Synthesis

Techniques to separate the outgrowth involving ethanol, 1-propanol, 1-butanoland water from the Fischer-Tropsch synthesis were studied in this thesis. An optimalprocess for the separation and purification of the alcohols has been proposed. It issignificant in industrialization of liquefied coal to synthesis-oil.Firstly, the feature of the outgrowth of Fischer-Tropsch synthesis was analyzed toput forward a preliminary scheme. Then, a math-model was created and the processwas simulated using the ASPEN PLUS software to get parameters for setting up adistillation assembly. Three thermodynamic models (Wilson, NRTL, UNIQUAC)were tested for modeling the system. Finally, optimal operating parameters wereobtained from experiments.The experiments were conducted using three distillation columns. Theexperimental results and the simulations have been shown that the NRTL model is thebest one comparing to the others and that the optimal parameters are as follows.(1)The top sample of the ethanol separate column is the ethanol production. Thebottom sample is the mixture of 1-propanol, 1-butanol and water. The column is 41theoretical stages and feed stage is 20. Operating parameters are reflux rate 7:1 andD/F is 58%. (2)The top sample of the 1-propanol concentrate column is the mixture of1-propanol, 1-butanol and water. The bottom sample is water. The column is 8theoretical stages and feed stage is 4. Operating parameters are reflux rate 0.4:1;D/Fis 60%. (3)The top samples of the batch azeotropic column vary with time. Water isfully separated in this column. The bottom sample is the mixture of 1-propanal and1-butenal. If the operation goes on, 1-propanal will be separated from the top of thecolumn. This column has 38 theoretical stages.