Cloudpoint
In the petroleum industry, cloud point refers to the temperature below which wax in diesel or biowax in biodiesels forms a cloudy appearance. The presence of solidified waxes thickens the oil and clogs fuel filters and injectors in engines. The wax also accumulates on cold surfaces (producing, for example, pipeline or heat exchanger fouling) and forms an emulsion with water. Therefore, cloud point indicates the tendency of the oil to plug filters or small orifices at cold operating temperatures. An everyday example of cloud point can be seen in olive oil stored in cold weather. Olive oil begins to solidify at around 4 °C, whereas winter temperatures in temperate countries can often be colder than 0 °C. In these conditions, olive oil begins to develop white, waxy clumps of solidified oil that sink to the bottom of the container. In crude or heavy oils, cloud point is synonymous with wax appearance temperature (WAT) and wax precipitation temperature (WPT). The cloud point of a ...