Trihalosilane refining device having divided wall distillation column

Abstract

Trihalosilane refining device having a divided wall distillation column is disclosed. The trihalosilane refining device can be useful in obtaining high-purity trihalosilane from a feed containing a trihalosilane while consuming a small amount of energy.

Claims

1. A trihalosilane refining device comprising: a divided wall distillation column having an upper column region, a preliminary separation region, a main separation region and a lower column region formed therein and comprising an inlet port installed to introduce a feed containing a trihalosilane into the preliminary separation region, a first outlet port, a second outlet port and a third outlet port; and a first distillation column coupled to the divided wall distillation column, wherein the inlet port is installed at a 1/10 to 5/10 section of the preliminary separation region and wherein the second outlet port is formed at a 6/9 to 8/9 section of a divided wall section of the main separation region, and wherein the divided wall distillation column is a tray type designed to have a plate number so that a separation efficiency can be maintained at a level from 50% to 80% with respect to a theoretical plate number.

2. The trihalosilane refining device of claim 1, which has a structure in which the upper and lower column regions are open.

3. The trihalosilane refining device of claim 2, wherein the upper or lower column region has an open length of 800 mm to 3,500 mm.

4. The trihalosilane refining device of claim 1, wherein the divided wall distillation column has a gap between trays in a divided wall section within a range from 200 mm to 1,500 mm.

5. The trihalosilane refining device of claim 1, wherein the divided wall of the divided wall distillation column has a length of 30% or more with respect to a total theoretical plate number of the divided wall distillation column.

6. The trihalosilane refining device of claim 1, wherein the first distillation column is coupled to the divided wall distillation column to introduce a component flowing out through the second outlet port.

7. The trihalosilane refining device of claim 1, wherein the third outlet port is installed at the divided wall distillation column to enable outflow of a component in the lower column region, and the trihalosilane refining device further comprises a second distillation column coupled to the divided wall distillation column to introduce a component flowing out through the third outlet port.

8. The trihalosilane refining device of claim 1, further comprising a third distillation column installed to introduce a component flowing out from a lower portion of the first distillation column.

9. The trihalosilane refining device of claim 1, wherein the first outlet is installed to enable outflow of a component in the upper column region, the second outlet port is installed to enable outflow of a component in the main separation region and the third outlet port is installed to enable outflow of a component in the lower column region.

10. The trihalosilane refining device of claim 9, wherein the first outlet port is installed so as to satisfy the following Expression 2:
0.0139P.sup.3−0.6467P.sup.2+12.692P+27.716≦Tt≦0.0139P.sup.3−0.6467P.sup.2+12.692P+37.716  Expression 2 wherein Tt represents a temperature (° C.) of the first outlet port or the component flowing out through the first outlet port and P represents an operating pressure (Kg/sqcmG) of the upper column region of the divided wall distillation column.

11. The trihalosilane refining device of claim 9, wherein the second outlet port is installed so as to satisfy the following Expression 1:
0.0132P.sup.3−0.624P.sup.2+12.673P+41.371≦Tm≦0.0132P3−0.624P2+12.673P+51.371  Expression 1 wherein Tm represents a temperature (° C.) of the second outlet port or the component flowing out through the second outlet port, and P represents an operating pressure (Kg/sqcmG) of the upper column region of the divided wall distillation column.

12. The trihalosilane refining device of claim 9, wherein the third outlet port is installed so as to satisfy the following Expression 3:
0.016P.sup.3−0.7386P.sup.2+14.3P+78.759≦Tb≦0.016P.sup.3−0.7386P.sup.2+14.3P+88.759  Expression 3 wherein Tb represents a temperature (° C.) of the third outlet port or the component flowing out through the third outlet port and P represents an operating pressure (Kg/sqcmG) of the upper column region of the divided wall distillation column.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a diagram showing a divided wall distillation column according to one illustrative embodiment;

(2) FIGS. 2 and 3 are graphs illustrating a concentration profile of trichlorosilane present in a divided wall section of a main separation region of the divided wall distillation column;

(3) FIG. 4 is a diagram showing a trihalosilane refining device used in Example 1; and

(4) FIG. 5 is a diagram showing a trihalosilane refining device used in Comparative Example 1.

BRIEF DESCRIPTION OF PARTS IN THE DRAWINGS

(5) 100 and 31: divided wall distillation column 101: divided wall 102: condenser 103: reboiler 104: upper column region 105: lower column region 106: preliminary separation region 107: main separation region F: feed EU, EM and ED: effluent DW: divided wall section, preliminary or main separation region or length thereof 32 to 34: first to third distillation columns of Example 1 41 to 45: first to fifth distillation columns of Comparative Example 1 A to K: respective streams in Example 1 or Comparative Example 1

ILLUSTRATIVE EMBODIMENTS

(6) Hereinafter, the method will be described in detail referring to Examples and Comparative Examples; however the scope of the method is not limited to the below description.

Example 1

(7) A trihalosilane refining device having a structure shown in FIG. 4, for example, a structure in which a divided wall distillation column 31, a first distillation column 32, a second distillation column 33 and a third distillation column 34 were coupled to each another, was used to prepare a feed containing trichlorosilane using a conventional method. Then, a simulation was performed on a process of refining the feed containing the trichlorosilane. The simulation was performed using Aspen Plus, and the conditions used for the simulation are listed in the following Tables 1 and 2. In the process, the feed introduced into the distillation column 31 was introduced through the outlet port installed at a point corresponding to 3/10 of a length of the preliminary separation region of the distillation column 31 from a top portion (an upper column region) of the preliminary separation region, and the effluent containing a trichlorosilane flowed out through the second outlet port installed at a point corresponding to 7/9 of a length of the divided wall section of the distillation column 31 from a top portion (an upper column region) of the divided wall section. Upon the simulation, an upper column pressure of the distillation column 31 was maintained at approximately 5.8 Kg/sqcmG. In the trihalosilane refining device, the length of the divided wall of the divided wall distillation column 31 was set to be approximately 30% with respect to the total theoretical plate number of the distillation column 31, and an upper column pressure of the distillation column 31 was maintained at approximately 5.8 Kg/sqcmG upon the simulation.

(8) TABLE-US-00001 TABLE 1 Items of divided wall distillation column 31 Theoretical plate number Upper column region 18 Preliminary separation region 38 Main separation region 38 Lower column region 20

(9) TABLE-US-00002 TABLE 2 First Second Third distillation distillation distillation column column column Theoretical plate number 45 40 24 Feed introduction plate 29 5 13

(10) The results obtained for respective streams (indicated by A to J in FIG. 4) based on the simulation results are listed in the following Tables 3 and 4.

(11) TABLE-US-00003 TABLE 3 Stream No. A B C D E F G H I J Temperature 60.0 59.4 101.4 144.9 76.6 157.2 49.8 55.1 49.8 57.3 (° C.) Pressure 5.6 5.8 6.1 6.2 0.8 1.0 0.8 1.1 0.8 1.1 (Kg/sqcmG) Flow rate 1,909 22 1,640 247 190 57 30 1,610 1,600 10 (Kg/hr) Mass fraction (%) HCl 0.26 22.561 0 0 0 0 0 0 0 0 DCS 0.52 42.122 0 0 0 0 0 0 0 0 BCL3 0.01 0.868 0 0 0 0 0 0 0 0 TCS 86.20 34.449 99.914 0.027 0.035 0 100 99.913 100 85.918 STC 10.00 0 0.086 76.710 99.723 0 0 0.087 0 14.082 PCL3 0.01 0 0 0.077 0.1 0 0 0 0 0 Heavies 3.0 0 0 23.186 0.142 100 0 0 0 0 HCl: hydrochloric acid DCS: dichlorosilane BCL3: boron trichloride TCS: trichlorosilane STC: silicon tetrachloride PCL3: phosphorus trichloride Heavies: other high boiling point component

(12) TABLE-US-00004 TABLE 4 Divided wall First Second Third distillation distillation distillation distillation column column column column Calorie 2.300 0.017 1.613 1.161 consumption (Gcal/hr)

Comparative Example 1

(13) A trihalosilane refining device having a structure in which five conventional distillation columns were coupled to each another as shown in FIG. 5 was used to simulate a process of refining trichlorosilane present in the same feed as used in Example 1. The simulation was performed in the same Aspen Plus as used in Example 1. The conditions used for the simulation are listed in the following Table 5.

(14) TABLE-US-00005 TABLE 5 First Second Third Fourth Fifth distillation distillation distillation distillation distillation column 41 column 42 column 43 column 44 column 45 Theoretical 45 40 40 45 24 plate number Feed 13 11 11 9 13 introduction plate

(15) The results obtained for respective streams (indicated by A to K in FIG. 5) based on the simulation results are listed in the following Tables 6 and 7.

(16) TABLE-US-00006 TABLE 6 Stream No. A B C D E F G H I J K Temperature 90.0 55.6 102.8 49.9 85.1 76.1 152.4 49.8 55.1 49.8 56.9 (° C.) Pressure 5.6 5.8 5.8 0.8 0.8 0.8 1.0 0.8 1.1 0.8 1.1 (Kg/sqcmG) Flow rate 1909 20 1889 1640 249 190 59 30 1610 1600 10 (Kg/hr) Mass fraction (%) HCl 0.26 24.817 0 0 0 0 0 0 0 0 0 DCS 0.52 49.634 0 0 0 0 0 0 0 0 0 BCL3 0 0.954 0 0 0 0 0 0 0 0 0 TCS 86.2 24.595 86.852 99.93 0.719 0.942 0 99.99996 99.929 100 89.494 STC 10 0 10.106 0.07 76.205 99.058 2.609 0.00004 0.071 0 11.056 PCL3 0.02 0 0.01 0 0.076 0 0.323 0 0 0 0 Heavies 3 0 3.032 0 23 0 97.068 0 0 0 0 HCl: hydrochloric acid DCS: dichlorosilane BCL3: boron trichloride TCS: trichlorosilane STC: silicon tetrachloride PCL3: phosphorus trichloride Heavies: other high boiling point component

(17) TABLE-US-00007 TABLE 7 First Second Third Fourth Fifth distillation distillation distillation distillation distillation column 41 column 42 column 43 column 44 column 45 Calorie 9.458 0.172 1.617 0.043 1.161 consumption (Gcal/hr)

(18) As seen from the results, it was revealed that the energy (2.300 Gcal/hr) consumed at the divided wall distillation column used in Example 1 was significantly lower than the energy (9.458 Gcal/hr+0.172 Gcal/hr) consumed at the first and second distillation columns 41 and 42 used in Comparative Example 1, which served as the divided wall distillation column used in Example 1. More particularly, it was confirmed that the energy was reduced by 7.330 Gcal/hr for an energy curtailment of approximately 76%. In comparison of the entire processes (the processes performed in the divided wall distillation column and the first to third distillation columns used in Example 1 versus the processes performed in the first to fifth distillation columns used in Comparative Example 1), it could be seen that the energy was reduced by approximately 7.36 Gcal/hr in Example 1 for an energy curtailment of approximately 59%, compared with Comparative Example 1.