Method and a system for monitoring and control of fouling and optimization thereof of two side membrane fouling process

Patent metadata

Field	Value
Publication number	US-9737858-B2
Application number	US-201114369975-A
Country	US
Kind code	B2
Filing date	Dec 23, 2011
Priority date	Dec 23, 2011
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

Methods are disclosed for monitoring, controlling and optimizing fouling of a two side membrane fouling process. The method for monitoring fouling of a two side membrane fouling process can include determining the process model for the two side membrane fouling process. The parameters of the process model can be grouped based on the interactions thereof between the parameters so as to form one or more groups of parameters. At least one key performance index is estimated in relation to one or more groups of parameters. The fouling of the two side membrane fouling process is monitored correspondingly in relation to at least one key performance index.

First claim

We claim:

1. A method for controlling fouling on and cleaning of a feed side and a draw side of a membrane wherein the feed side includes a feed solution and the draw side includes a draw solution, the method comprising:
providing a process model for operation of the feed side and draw side of the membrane, wherein the process model includes one or more parameters indicative of at least one of external concentration polarisation and internal concentration polarisation;
estimating a feed side key performance index and a draw side key performance index from the one or more parameters of the process model;
estimating fouling on the feed side and fouling on the draw side of the membrane based on the feed side key performance index and the draw side key performance index;
altering flow of at least one of feed solution or draw solution based on the estimated fouling at the feed side and the estimated fouling at the draw side for controlling fouling on the feed side and draw side of the membrane to maintain substantially the same fouling rate at the feed side and the draw side of the membrane; and
concurrently cleaning the feed side and the draw side of the membrane.

2. The method as claimed in claim 1 , comprising:
controlling a two side membrane process by estimating optimal operating conditions for the two side membrane process based on an objective function, and by considering fouling of the membrane.

3. The method as claimed in claim 2 , wherein the objective function comprises one or more objectives, which include at least one of increasing energy production, scheduling of membrane maintenance, and distribution of load.

4. The method as claimed in claim 1 , wherein the parameters comprise:
at least one of water permeability, solute permeability, reflection coefficient, mass transfer coefficient, Darcy's coefficient, flux, density, viscosity, diffusivity, velocity, flow rate, pressure, salt concentration, and temperature.

5. The method as claimed in claim 4 , wherein at least one of the parameters corresponds to a parameter of water and/or solute.

6. The method as claimed in claim 4 , wherein at least one of the parameters corresponds to a parameter of feed and/or draw solution.

7. The method as claimed in claim 1 , wherein each said key performance index comprises:
a membrane fouling parameter of either side or both sides of the membrane in relation to feed and/or draw solution.

8. The method as claimed in claim 1 , performed online or offline.

9. A method for controlling fouling of a two side membrane fouling process, the method comprising:
determining a process model for the two side membrane fouling process;
grouping parameters of the process model, based on interactions between the parameters, to form one or more groups of parameters;
estimating at least one key performance index in relation to the one or more groups of parameters;
controlling fouling of the two side membrane fouling process in relation to the at least one key performance index by altering a flow of solution on either side or on both sides of the two side membrane to maintain substantially the same fouling rate on both sides of the two side membrane; and
concurrently cleaning both sides of the two side membrane.

10. The method as claimed in claim 9 , comprising:
altering the flow of solution when a fractional change in the key performance index exceeds a predetermined percentage of a threshold value.

11. The method as claimed in claim 9 , comprising:
controlling the two side membrane process by estimating optimal operating conditions for the two side membrane process based on an objective function, and by considering fouling of the two side membrane.

12. The method as claimed in claim 11 , wherein the objective function comprises:
one or more objectives, which include at least one of increasing energy production, scheduling of membrane maintenance, and distribution of load.

13. The method as claimed in claim 9 , wherein the parameters comprise:
at least one of water permeability, solute permeability, reflection coefficient, mass transfer coefficient, Darcy's coefficient, flux, density, viscosity, diffusivity, velocity, flow rate, pressure, salt concentration, and temperature.

14. The method as claimed in claim 13 , wherein at least one of the parameters corresponds to a parameter of water and/or solute.

15. The method as claimed in claim 13 , wherein at least one of the parameters corresponds to a parameter of feed and/or draw solution.

16. The method as claimed in claim 9 , wherein the key performance index comprises:
a membrane fouling parameter of either side or both sides of the two side membrane in relation to feed and/or draw solution.

17. The method as claimed in claim 9 , comprising:
altering the flow of solution when a fractional change in the key performance index exceeds a predetermined percentage of a threshold value.

18. A system in a plant employing a membrane separation process, comprising:
means for: storing a process model regarding operation of the feed side and draw side of a membrane, wherein the process model includes one or more parameters indicative of at least one of external concentration polarisation and internal concentration polarisation, for estimating a feed side key performance index and a draw side key performance index from the one or more parameters of the process model, and for estimating fouling on the feed side and fouling on the draw side of the membrane based on the feed side key performance index and the draw side key performance index; and
means for altering flow of at least one of feed solution or draw solution based on the estimated fouling at the feed side and the estimated fouling at the draw side for controlling fouling on the feed side and draw side of the membrane to maintain substantially the same fouling rate at the feed side and the draw side of the membrane in order to allow concurrent cleaning of the feed side and the draw side of the membrane.

19. A system in a plant employing a membrane separation process and/or a power generation process, comprising:
means for: determining and storing a process model regarding a two side membrane fouling process, for grouping parameters of the process model, based on interactions between the parameters, to form one or more groups of parameters, and for estimating at least one key performance index in relation to the one or more groups of parameters; and
means for controlling fouling of the two side membrane fouling process in relation to the at least one key performance index by altering a flow of solution on either side or on both sides of the two side membrane to maintain substantially the same fouling rate on both sides of the two side membrane in order to allow concurrent cleaning of both sides of the two side membrane.

Assignees

• Subbiah Senthilmurugan
• Mekapati Srinivas
• Abb Schweiz Ag

Inventors

• Subbiah Senthilmurugan
• Mekapati Srinivas

Classifications

• B01D2311/16

  Flow or flux control · CPC title

• B01D61/025

  Reverse osmosis; Hyperfiltration · CPC title

• B01D61/58

  Multistep processes · CPC title

• B01D2311/10

  Temperature control · CPC title

• B01D61/12

  Controlling or regulating · CPC title