Development and implementation of analyzer based control system and algorithm

Patent metadata

Field	Value
Publication number	US-9834732-B2
Application number	US-201615284770-A
Country	US
Kind code	B2
Filing date	Oct 4, 2016
Priority date	Jul 25, 2012
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A method of correcting measurements of a chemical sensor used in an industrial facility. The method involves correcting for errors known to occur in the steady state and the dynamic state for specifically recognized situations. This method allows for correcting errors that occur due to deadtime, false zero measurements, and non-linear disturbances. The method combines automated measurement techniques and human know how to progressively learn and refine the accuracy of the corrections.

First claim

What is claimed is:

1. A method of controlling corrosion rate of a crude oil refinery process comprising:
measuring copper concentration of the crude oil refinery process to establish an initial corrosion rate of the crude oil refinery process;
measuring pH of the crude oil refinery process;
measuring chloride concentration of the crude oil refinery process;
altering the initial corrosion rate of the crude oil refinery process according to the measured pH and the measured chloride concentration and correcting for dynamic state error, thereby determining an altered corrosion rate;
comparing the altered corrosion rate to a pre-determined range of acceptable values;
if the altered corrosion rate is outside of the pre-determined range of acceptable values, performing a remedial measure to change the altered corrosion rate to a value within the range of acceptable values; and
repeating the steps.

2. The method of claim 1 , wherein the remedial measure comprises adding to the crude oil refinery process a chemical selected from the group consisting of: a neutralizer, a caustic agent, a filming inhibitor, and combinations thereof.

3. The method of claim 1 , wherein the remedial measure comprises adding a neutralizer to the crude oil refinery process.

4. The method of claim 3 , wherein the neutralizer is selected from the group consisting of 3-methoxypropylamine, monoethanolamine, N,N-dimethylaminoethanol, methoxyisopropylamine, and combinations thereof.

5. The method of claim 1 , wherein the remedial measure comprises adding a caustic agent to the crude oil refinery process.

6. The method of claim 5 , wherein the caustic agent is 7.5° to 14° Baume sodium hydroxide solution.

7. The method of claim 1 , wherein the remedial measure comprises adding a filming inhibitor to the crude oil refinery process.

8. The method of claim 7 , wherein the filming inhibitor is selected from the group consisting of: an oil soluble blend of amides, an oil soluble blend of imidazolines, and an oil soluble blend of amides and imidazolines.

9. The method of claim 1 , wherein the altering step comprises performing a regression analysis to determine the altered corrosion rate.

10. A method of controlling corrosion rate of a crude oil refinery process comprising:
measuring copper concentration of the crude oil refinery process to establish an initial corrosion rate of the crude oil refinery process;
measuring pH of the crude oil refinery process;
measuring chloride concentration of the crude oil refinery process;
altering the initial corrosion rate of the crude oil refinery process according to the measured pH and the measured chloride concentration, and correcting for dynamic state error and steady state error, thereby determining an altered corrosion rate;
comparing the altered corrosion rate to a pre-determined range of acceptable values;
if the altered corrosion rate is outside of the pre-determined range of acceptable values, performing a remedial measure to change the altered corrosion rate to a value within the range of acceptable values; and
repeating the steps.

11. The method of claim 10 , wherein the remedial measure comprises adding to the crude oil refinery process a chemical selected from the group consisting of: a neutralizer, a caustic agent, a filming inhibitor, and combinations thereof.

12. The method of claim 10 , wherein the altering step comprises performing a regression analysis to determine the altered corrosion rate.

Assignees

• Nalco Co
• Nalco Company Llc

Inventors

• Wang Jin
• Hilton Nigel P
• Scattergood Glenn L
• Ferguson Sam

Classifications

• G05B23/0221

  Preprocessing measurements, e.g. data collection rate adjustment; Standardization of measurements; Time series or signal analysis, e.g. frequency analysis or wavelets; Trustworthiness of measurements; Indexes therefor; Measurements using easily measured parameters to estimate parameters difficult to measure; Virtual sensor creation; De-noising; Sensor fusion; Unconventional preprocessing inherently present in specific fault detection methods like PCA-based methods · CPC title

• G06F11/00 Primary

  Error detection; Error correction; Monitoring (error detection, correction or monitoring in information storage based on relative movement between record carrier and transducer G11B20/18; monitoring, i.e. supervising the progress of recording or reproducing G11B27/36; in static stores G11C29/00) · CPC title

• C10G75/02 Primary

  by addition of corrosion inhibitors · CPC title

• G05B23/02 Primary

  Electric testing or monitoring · CPC title

• G01N17/02

  Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement · CPC title