Gasoline Blending

Gasoline blending is a complex refining process as operating personnel are required to meet fuel quality and legislative targets while operating at the lowest possible costs.

To meet these operating targets, typical properties that are measured and controlled include RON, MON, RVP, Aromatics, Benzene, Olefins, ASTM-D86 Distillation Points, and Oxygenates.

Traditionally, these measurements have been obtained by periodically stopping the blend to obtain laboratory validations or have been provided by a host of classical on-line analytical techniques, e.g. Octane Engines and Gas Chromatographs.

There are, however, a number of problems associated with these approaches. These include the high capital and operating costs of multiple techniques, slow response time and in many cases, poor analytical repeatability.

These disadvantages are especially evident in the utilization of octane engines. These performance issues can lead to significantly higher blending costs due to unavoidable "property giveaway", as well as reduced blender throughput, coupled with increased inventory and demurrage costs.

In the early 1990s, petroleum refiners started to implement Near-Infrared (NIR) technology on gasoline blenders. The direct replacement of the octane engine was a primary driver in these installations.

The technology promised to solve many of the problems associated with traditional analytical techniques.

NIR technology would provide essentially real-time analyses and was capable of multi-stream and multi-property application.

The capital and operating cost benefits were very attractive when compared to traditional approaches.

The improvement in analytical speed and data quality would allow operators to blend continuously, faster and more tightly with respect to operating quality targets.

This would lead to an increase in blender throughput, faster grade changes and ultimately reduced quality "giveaway".


Unfortunately, for many operators who invested heavily in NIR gasoline projects, the reality was somewhat different. It is fair to say that refiners now consider the implementation of NIR technology on gasoline blenders as a risky investment.


The technique of NIR spectroscopy is a correlative secondary method, which can ultimately be only as accurate as the reference methods that provide primary calibration data, e.g. gas chromatograph analysis for olefins or aromatics content.

The client’s reference data is definitely the key driver in NIR performance, given a stable spectrometer as a base development platform. NIR will only mimic the reference data in terms of accuracy.

It can match and track the data from a good reference method. It cannot improve the accuracy of a poor reference method.

• Easyir Gasoline is the solution!