Real time optimization of batch processes

• US 10,133,268 B2
• Filed: 12/17/2014
• Issued: 11/20/2018
• Est. Priority Date: 01/30/2014
• Status: Active Grant

• Current Assignee: ExxonMobil Research & Engineering Company (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Research & Engineering Company (Exxon Mobil Corporation)
• Inventors: Bokis, Constantinos, Georgiou, Apostolos T., Hanratty, Peter J.
• Primary Examiner(s): Lo, Kenneth M
• Assistant Examiner(s): Shafayet, Mohammed
• Application Number:
  US14/573,090
• Publication Number:
  US 20150212501A1
• Time in Patent Office: 1,434 Days
• Field of Search: 700272, 700 28, 700 36, 700 29, 700268, 700 40
• CPC Class Codes: G05B 13/021 in which a variable is automatically adjusted to optimise the performance
• CPC Class Codes: G05B 23/0294 Optimizing process, e.g. process efficiency, product quality

Abstract

Systems and methods for optimizing a system operating in a first mode of operation include detecting an event associated with a cycle in a first mode of operation. When the cycle ends (i.e., when another event is detected), steady state criteria is applied to determine whether data associated with the cycle satisfies the steady state criteria. Optimization targets can be calculated based on the data associated with the cycle. Control signals including the optimization targets can be applied to a next cycle operating in the first mode of operation to improve process performance.

Claims

1. A method for optimizing a batch process system operating in at least one mode of operation, wherein the batch process system having successive cycles of operation in the at least one mode of operation, the method comprising:

detecting an event associated with a cycle of operation of the batch process system operating in a first mode of operation by obtaining data associated with current operation of the batch process system;

determining, using one or more processors, whether the obtained data associated with the cycle of operation satisfies steady state criteria,

wherein determining whether the data associated with the cycle satisfies the steady state criteria comprises;

selecting an offset, the offset is a transient period in which no data is recorded, obtaining data following the offset, and determining whether the data following the offset from the event satisfies the steady state criteria,

wherein determining whether the data following the offset from the event satisfies the steady state criteria comprises;

separating the cycle into a first cycle portion and a second cycle portion, averaging a first set of data associated with the first cycle portion, averaging a second set of data associated with the second cycle portion, and determining whether the average of the first set of data and the average of the second set of data are within a predetermined tolerance of an overall average, wherein the overall average is the average of all data including the first set of data and the second set of data;

generating, using one or more processors, optimization targets for the first mode of operation based on the obtained data; and

applying control signals comprising the optimization targets, using one or more processors, for a subsequent cycle of operation of the batch process system, when the batch process system is operating in the first mode of operation during a subsequent cycle of operation.

2. The method of claim 1, wherein the event comprises a drum change event, wherein the drum change event includes switching operation from one drum to another drum.

3. The method of claim 1, wherein the event comprises an online spalling transition event.

4. The method of claim 1, wherein the offset is selected based on a time period of transient behavior in previous cycles operating in the first mode of operation.

5. The method of claim 1, wherein the offset is about 90 minutes.

6. The method of claim 1, wherein determining whether the data following the offset associated with the cycle satisfies the steady state criteria further comprises comparing a maximum value and a minimum value to the overall average.

7. The method of claim 1, wherein the control signals further comprise optimized values for control variables.

8. The method of claim 1, wherein the optimization targets comprise at least one of a reflux flow rate, a pumparound flow rate, an overhead temperature, and overhead product specification, and a bottom product specification.

9. The method of claim 1, further comprising:

detecting a second event associated with a second cycle operating in the first mode of operation;

determining that data associated with the second cycle satisfies the steady state criteria;

adjusting the optimization targets for the first mode of operation based on the data associated with the second cycle; and

applying second control signals comprising the adjusted optimization targets for a subsequent cycle in the first mode of operation.

10. The method of claim 1, further comprising:

detecting a second event associated with a second cycle operating in the first mode of operation;

determining that data associated with the second cycle does not satisfy the steady state criteria; and

applying the control signals comprising the optimization targets, without adjusting the optimization targets based on the data associated with the second cycle, for a subsequent cycle in the first mode of operation.

11. An apparatus for optimizing a batch process system having at least one operating mode, wherein the batch process system having successive cycles of operation in the at least one mode of operation, the apparatus comprising:

at least one sensor configured to monitor the system to obtain data associated with the operation of the system during a cycle of operation and detect an event associated with a cycle operating in a first mode of operation; and

at least one processor operatively connected to the at least one sensor,

wherein the at least one processor determines whether or not the event associated with the cycle operating in the first mode of operation is operating in a steady state based upon a determination whether data associated with the cycle satisfies steady state criteria,

wherein the determination whether the data associated with the cycle satisfies the steady state criteria comprises;

selecting an offset, the offset is a transient period in which no data is recorded, obtaining data following the offset, and determining whether the data following the offset from the event satisfies the steady state criteria,

wherein determining whether the data following the offset from the event satisfies the steady state criteria comprises;

separating the cycle into a first cycle portion and a second cycle portion, averaging a first set of data associated with the first cycle portion, averaging a second set of data associated with the second cycle portion, and determining whether the average of the first set of data and the average of the second set of data are within a predetermined tolerance of an overall average, wherein the overall average is the average of all data including the first set of data and the second set of data, and

wherein the at least one processor generates optimization targets for the first mode of operation based on the data;

a database for storing the optimization targets generated by the at least one processor; and

a controller configured to apply control signals comprising the optimization targets for a next cycle of operation of the batch process system operating in the first mode of operation.