Particle & Surface Sciences distribute Clemex products throughout Australia and New Zealand. Petroleum is a naturally occurring, flammable liquid found in rock formations in the earth, consisting of organic compounds and complex hydrocarbons.
These hydrocarbons consist of long chains of carbon and hydrogen molecules which, once refined, break down into a variety of products such as gasoline, diesel, kerosene, fuel oil, solvents, fertilizers, pesticides, and plastics. Other products, such as asphalt, can also be “cracked” by modern refineries into more valuable products.
Cracking is a process whereby complex organic molecules are broken down into simpler molecules by the shattering of carbon-carbon bonds. In fluid catalytic cracking the long-chain molecules of high boiling hydrocarbon liquids are turned into much shorter molecular chains at elevated temperature by means of a fluidised powdered catalyst.
The powdered catalyst consists of small ceramic balls, or beads, about 1 to 2 microns in diameter. These beads, packed in columns, draw out impurities from crude oil as it passes through. During this process, the beads wear down, and by doing so, lose their properties as catalysts due to a reduction of surface area.
Clemex was provided with four vials containing ceramic beads. The purpose of the analysis was to see if the software could classify a group of beads by degree of wear. The vials were numbered:
- Vial #1 containing pristine beads
- Vial #2 containing slightly worn beads
- Vial #3 containing worn beads
- Vial #4 containing fragmented beads
The beads were randomly placed onto a sticky surface in order to prevent them from moving around. If a large number of samples were to be analysed, the use of a grid to hold the samples in place should be considered. The motorised stage’s movement would thus always be the same. Given the size of the beads (± 2mm), a low-power objective must be used to keep them entirely within the visible area (as much as possible). Nevertheless, the magnification should be high to resolve the texture of the ball’s surface. A magnification of 50X was found to be the best compromise for this analysis.
Considering the shape of the beads and the magnification used, it is only possible to focus on small sections of an object at the same time. The multi-layer grab instruction is important in reconstructing the complete image from the several images taken at different Z positions, each containing only a small area in focus. The Z displacement of the motorized stage was doubled in order to increase the speed of the Multi-layer grab instruction. It was found that reflected light and a black background are the conditions that allow for the best contrast of surface details, and thus to obtain the greatest variation in gray levels from one category to another.
Using the analyser, a number of different factors were measured on beads belonging to each of the four categories. The results obtained were compared using graphs, and those which showed a clear-cut variation between categories were retained for use. These factors are size, gray intensity, and texture. Although none of these three factors alone are enough to categorise the beads according to the four wear levels, their combined use makes classification possible. For a group of beads, the Clemex Vision PE image analysis system can automatically calculate the percentage of each of the four categories to which they belong. From there, the final classification is done.
The Clemex Vision PE image analysis system can be used for the following applications:
- Pharmaceutical Industry
- Materials Industry
- Chemical Industry