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Petroleum Solutions - Octane and More

Operations Gasoline blending Diesel blending Reforming Pipelines Benefits Reduced giveaway Higher unit throughput Eliminate re-blends Reduced production costs Instant feedback Multiple sample points

Gasoline RON, MON, (R+M)/2 Oygenates Distillation points Olefins Benzene Reid Vapor Pressure Haze Diesel Cetane index Cetane number Cloud point Flash point ASTM Color & Haze Red dye Aviation Saybolt Color Haze

NIR is ideally suited for continuous monitoring in refineries.  For example, NIR spectra of gasoline with various octane ratings are shown here, where the wavelength of light is plotted on the horizontal axis and absorbance is plotted on the vertical axis. Notice that aromatic (1150 nm) and aliphatic (1200 nm) hydrocarbons have distinct signals and are important in establishing a calibration.   Absorbance responds to concentration changes.   These spectral changes represent large changes in properties, such as octane number.

Guided Wave analyzers come equipped with all the computational methods to convert these spectral variations into octane number, benzene, oxygenates, etc. in real time.

The trend shown here is based upon such a calibration of NIR spectra of the type shown above for Research Octane Number, RON.  This trend reflects a two month period comparing real-time NIR predictions and RON values generated by a knock engine on grab samples.

This is typical of what real-time monitoring can provide. Notice the greater variability in the latter part of the trend.  This helped the process quality engineers to improve the process even further.

NIR monitoring provides with you with real-time monitoring to catch upsets, minimize the number of grab samples taken back to your field lab.  This saves you money in terms of adding just the right amount of oxygenates and additives.

Our SpectrOn system can measure all of these properties sequentially at up to 11 sample points.  We have the expertise to help you using the experience gained from over 100 SpectrOn systems in place worldwide, including calibration support, training and spare parts.  This includes:

• SpectrOn NIR analyzer for up to 11 sample streams
• ROSA for capturing grab samples adjacent to the flow cell
  
• SCS sample conditioning system to eliminate haze and control temperature
• Optical validation
• Preliminary model development
• CLASS PA and CLIENT SERVER control software for MODBUS
• Optional service contracts for remote model maintenance

It is crucial to understand that any optical measurement is dependent upon the quality of the sample presented to it.  This is why we spend so much effort in providing you with the means to condition your sample before it is analzyed with one of our remote fiber optic sample cells. This is an example of our SCS system. It first cools the sample stream and then removes any haze that develops. It then heats the sample prior to passing through the optical flow cell, thereby ensuring  sample clarity for the best possible prediction of the parameter of interest, such as cetane.  It also provides the means to clean the optical flow cell with a solvent.

Color and haze are also frequently monitored as indicators of process upsets and for product release.  They are also measured in pipelines during transport. 

Haze is a measure of water content.  Like so many measurements, it was traditionally a visual measurement (ASTM D4176) where a 100 mm diameter jar was filled with fuel and ranked 1 through 6 in front of a laminated ASTM page with horizontal lines of varying thicknesses, as shown here.  We can now quantify this on-line in real time, as we have done with other fuel color measurements.

Optical Solutions' brand of SMART photometers have been installed worldwide, such as our ClearView,to measure:

• Saybolt (-15 to +30) in aviation fuel
• ASTM (D1500) in diesel fuel (1-7) and gas oil
• Haze (D4176)  (1-6)
• Red dye in non-automotive diesel (0-1 ppm and 1-20 ppm) for North America

If color is the critical parameter, we can remove any haze with sample conditioning systems, such as SCS shown above.  We have fiber optic insertion probes with retraction devices where high sample stream pressures (1500 psi) pose a worker safety problem. This picture shows an installation in Europe with our insertion probe and retraction device. It is measuring color.  The line pressure or plant air keeps the insertion probe in the pipe.  Releasing this pressure allows retraction for cleaning and validation.