| Deut Distillation Column(DDC) added a deut to a distillation and replaced two distillation columns used in conventional process to separate three cuts mixture. Compared with conventional process,DDC shortened the flow path and consumed less energy and facilities;Compared with Dividing Wall Column,DDC used a deut to replace a divided wall and could avoid leaking and help to increase the sufurce for heat exchanging, So it is nessary to study DDC.To study the charecteristics of the DDC, A simulation software called ASPEN PLUS was used to simulate the process of Aromatic Mixture separation with DDC and compute parameter concerned.By simulation and investigation, the optimum conditions were:the stage number of main column was 30;the stage number of side column was 12;the feed stage was on the 6th stage in pre-column;the consist of BTX was 1:3:1;the side-draw stage was on the 12 stage in main-column;reflux ratio was 7;liquid split ratio was 2.7;vapour split ratio was 0.8;the deut column was on the middle area of the distillation column.Copared with conventional process,DDC spared a distillation column,a condenser and a reboiler, the equipments consumption could be reduced,the energy consumption could be reduced by more than 27%.A deut distillation column was designed and made to study the process for the separation of pyrolysis gasoline, The material of the deut column was stainless steel, the other part was hard glass. The height of the column was 7.2m and the deut column was 2m, its diameter was from 50mm to 70mm, the column was packed by glass-spring packing. The material flowed into the middle section of the side column after it was heated, the side-draw product was obstained from the lower end of region of withdrawal part. By ivestigating the influence of reflux ratio, distribution ratio of liquid, flux of top product, flux of side-draw product and the position of the side-draw on the contain of C6～C8 in the side-draw flow, the optimum conditions were decided which were feed flow rate was 6L/h, the top flow rate was 1.08L/h, the side-draw flow rate was 3.0L/h, the distribution ratio of liquid was 3, the reflux ratio was 5.5.under the condition the mass fraction of C5 reached 99.60% in top-draw product;C6～C8 in side-draw stream reached 99.76%;C6 in bottom-draw is 0.21%.The result indicated that the study basically achieved the seperate request.The process of pyrolysis gasoline separation with DDC was also simulated with ASPEN PLUS. the optimum conditions were:main column had 48 stages;pre-column had 12 stages; the feed stage was on the 6th stage in pre-column,reflux ratio was 6:1, liquid split ratio was 1:1, vapour split ratio was 2.5:1, side-draw product rate was 19.4kmol/h,the top-draw rate was 7.1kmol/h,under the conditions,the mass fraction of C5 could reach more than 96% in the overhead product;C6～C8 could reach more than 99% in the side-draw product;And C9 could reach more than 97% in product from the bottom of the column.Conventional process was also simulated,Compared with the conventional process,DDC required less energy, the energy consumption of reboiler could be reduced by 26.11%, and equipments consumption could be reduced by 13.33%. |
PDF Full Text Request