PRT 140: Lesson 7 Analytics and Miscellaneous Measurement

Objectives

  • Discuss and identify major analytical instruments
  • Discuss miscellaneous/specialty instruments
  • Activity – PID/Instrument ID
  • Test review

Reading

Terms to Know and Discuss

  • Hand-Held, In-Line
  • Visual, photometric
  • pH, ORP, Conductivity
  • Opacity, Turbidity
  • Chromatograph, Spectrometer
  • CEMS, personnel monitors
  • Quantitative, Qualitative
  • Rectilinear speed, Rotational speed

Why Monitor Analytical Variables?

  • Environmental Monitoring/Reporting
  • Mechanical integrity of Fixed Equipment
  • Economics
  • Product Quality Assurance

Which reason do you think is most important?

CEMS

  • Continuous Environmental Monitoring Systems
  • Reports emissions for EPA guidelines
  • Sometimes on stacks, emissions from fired equipment
  • Other systems required by regulation
  • Mechanical Integrity
  • Monitor corrosion rates
  • Monitor corrosive atmospheres/liquids
  • Monitor vibration, other indicators for rotating equipment

Economics

  • Find problems real-time
  • Correct problems real-time
  • Save money

Product Quality

  • Test finished products
  • Test production streams
  • May be dozens of parameters on products like fuels, chemicals

Qualitative vs. Quantitative

Qualitative

  • To trigger response
  • To make conversation
  • Normal discussions

Quantitative

  • To analyze in detail
  • To make process corrections

Examples

  • Baby, It’s cold outside (qualitative)
  • It’s -47 °F outside (quantitative)
  • There is benzene present in the air in the lab (qualitative)
  • There is 0.5 ppb benzene present in the air in the lab (quantitative)

Sampling System

  • Obtain a representative sample from the process stream.
  • Transport the sample to the analyzer while maintaining its physical/chemical integrity.
  • Analyze the sample.
  • Return the sample to the process or discard it appropriately.

Handheld Instrument

 

 

An illustration of a handheld instrument
A personal H2S handheld gas detector

In-Line Instrument

  • In-Line instruments are permanently installed within the process unit.
  • The data from in-line instruments is used in product quality control, and/or environmental reporting.

Personal Monitor

An example of a personal dosimeter
A Personal Dosimeter
[image-140-7-3] By Elfabriciodelamancha (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
Personal Dosimeter to Monitor VOC exposure

Employee wears dosimeter during regular work for required time period, then it is sent away for analysis –

Determines TWA, STEL readings –

QUANTITATIVE ANALYSIS

Lab Instrument

An example of a lab instrument
Lab Instrument
[image: 140-7-4] By Mirolka (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

pH

pH – acidity measurement – hydrogen ions specifically

  • Water systems and processes
  • Indications of corrosion, scaling issues
  • Scale = 0 to 14
    • <7 = Acid
    • >7 = Base (caustic)
    • 7 = neutral

ORP – Oxidation-Reduction Potential

  • Ratio of reducing agents to oxidizing agents in the sample
  • Free electron concentration
  • Similar to acid/base analysis

Chromatography

Packed columns for gas chromatography
[image 140-7-5] Image from LibrTexts.org
A chart showing a calibration curve
Chromatographic curve
[image 140-7-6]
  • Chromatography separates mixtures into components by forcing them through a ‘packed column’.
  • Gas flows through column, pushes material through – heavier molecules take longer to move through
  • As stream exits the column, different types of detectors used to read amount of material.
  • Data = time through column, size of peak on chart
  • Time through column = identify component
  • Size of peak on chart = amount of component
  • Use calibration standards to identify and quantify
  • Other methods of separation – ability to adsorb onto column, polarity, etc – same principles
pH   meter A Measures the amount of particulate matter in a gas stream by measuring the transmittance or absorption of light through the material
ORP meter B Measures the ratio of reducing agents to oxidizing agents
Conductivity meter C Separates the molecular components of a liquid or gas by forcing them through a packed column.
Chromatograph D Measures the hydrogen ion concentration
Turbidity analyzer E Measures the ability of a solution to conduct electricity
Opacity analyzer F Measures the amount of particulate matter in a liquid stream by measuring the amount of transmittance or absorption of light through the material

Vibration Monitors

  • Why is it important to monitor vibration on rotating equipment?
  • Excessive vibration is a sign that equipment is out of alignment
  • Excessive vibration is a sign that equipment is wearing out – could fail

Rotation/Speed monitors

  • Rectilinear = speed in a straight line – velocity
    • i.e. meters/second, feet/sec
  • Rotational = speed of revolution, for rotating equipment like pumps, motors
    • i.e rpm

Exercise

  • PID review
  • Instrument Functional description
  • Loop Analysis – how much can we do already?
  • Look Ahead…

 

A diagram for activity 1
Activity: Figure 1
[image-140-7-7]
Activity figure 2
[image 140-7-8]
 

An example instrument diagram
Activity 2
[image-140-7-9]
An example instrument diagram
Activity 3
[image-140-7-10]
An example instrument diagram
Activity 4
[image-140-7-11]