Process for distilling a crude composition in a rectification plant including an indirect heat pump

Patent metadata

Field	Value
Publication number	US-12053725-B2
Application number	US-202017629084-A
Country	US
Kind code	B2
Filing date	Jul 6, 2020
Priority date	Jul 22, 2019
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

A process for purifying a crude composition comprising rectifying the crude composition in a rectification plant. The rectification plant comprises a rectification column including: a first overhead condenser for condensing a head fraction, and a reboiler for evaporating a bottom fraction. A difference between a temperature of the head fraction and a temperature of the bottom fraction is less than or equal to 20° C. A heat pump is provided between the first overhead condenser and the reboiler. The heat pump is an indirect heat pump that is operated with water or methanol as a refrigerant, and the indirect heat pump includes an expansion valve and a compressor. The heat pump comprises a second condenser located upstream of the compressor.

First claim

The invention claimed is:

1. A process for purifying a crude composition comprising:
rectifying the crude composition in a rectification plant comprising a rectification column including: a first overhead condenser for condensing a head fraction, and a reboiler for evaporating a bottom fraction, wherein:
a difference between a temperature of the head fraction and a temperature of the bottom fraction is less than or equal to 20° C.,
a heat pump is provided between the first overhead condenser and the reboiler, the heat pump being an indirect heat pump that is operated with water or methanol as a refrigerant, the indirect heat pump including an expansion valve and a compressor,
the heat pump comprises a second condenser located upstream of the compressor,
an inlet line connects a tube side of the first overhead condenser with the second condenser, and
an outlet line connects the second condenser with the tube side of the first overhead condenser such that remaining vapor is sent to and condensed in the second condenser and condensate is sent back to the first overhead condenser.

2. The process in accordance with claim 1 , wherein the difference between the temperature of the head fraction and the temperature of the bottom fraction is less than or equal to 15ºC.

3. The process in accordance with claim 1 , wherein the temperature of the bottom fraction is 80° ° C. to 150° ° C.

4. The process in accordance with claim 1 , wherein the temperature of the head fraction is 65° ° C. to 130° C.

5. The process in accordance with claim 1 , wherein the crude composition includes a silane as a component to be purified.

6. The process in accordance with claim 1 , wherein the first overhead condenser is a shell and tube falling film evaporator.

7. The process in accordance with claim 1 , wherein the reboiler is a shell and tube falling film evaporator.

8. The process in accordance with claim 1 , wherein:
the indirect heat pump comprises: a vapor line that connects a tube side of the first overhead condenser with a shell side of the reboiler, and a condensate line that connects the shell side of the reboiler with the tube side of the first overhead condenser, and
the vapor line comprises the compressor and the condensate line comprises the expansion valve.

9. The process in accordance with claim 1 , wherein the compressor comprises one or more turbofans.

10. The process in accordance with claim 1 , wherein the compressor comprises one or more turbofans and droplets of water or methanol are sprayed into vapor flowing through the one or more turbofans so as to desuperheat the vapor.

11. A rectification plant comprising:
a rectification column, the rectification column comprising:
a first overhead condenser for condensing a head fraction;
a reboiler for evaporating a bottom fraction; and
a heat pump provided between the first overhead condenser and the reboiler, wherein:
the heat pump is an indirect heat pump that includes an expansion valve and a compressor, and
the heat pump comprises: a second condenser located upstream of the compressor, an inlet line connecting a tube side of the first overhead condenser with the second condenser, and an outlet line connecting the second condenser with the tube side of the first overhead condenser such that remaining vapor is sent to and condensed in the second condenser and condensate is sent back to the first overhead condenser.

12. The rectification plant in accordance with claim 11 , wherein the compressor comprises one or more turbofans.

13. The rectification plant in accordance with claim 11 , wherein the first overhead condenser is a first shell and tube falling film evaporator and the reboiler is another a second shell and tube falling film evaporator.

Assignees

• Sulzer Management Ag

Inventors

• Zuber Laurent
• Ni Lin Feng

Classifications

• B01D3/148

  in combination with at least one evaporator · CPC title

• B01D3/007 Primary

  Energy recuperation; Heat pumps · CPC title

• B01D1/2856

  The compressed vapour is used for heating a reboiler or a heat exchanger outside an evaporator · CPC title

• Y02B30/52

  Heat recovery pumps, i.e. heat pump based systems or units able to transfer the thermal energy from one area of the premises or part of the facilities to a different one, improving the overall efficiency · CPC title

• B01D3/14 Primary

  Fractional distillation {or use of a fractionation or rectification column} · CPC title