ANS:C - aromatics

In the Edeleanu process, the extractor temperature is maintained at -20°C to reduce the aromatics content of kerosene. Here’s why:

• Edeleanu Process: This is a selective solvent extraction process used primarily to remove aromatic compounds from kerosene and other middle distillates. Aromatic compounds have higher solubility in selective solvents at lower temperatures.
• Temperature Control: By maintaining a low temperature (-20°C), the solubility of aromatic hydrocarbons in the solvent (usually furfural or phenol) is enhanced. This facilitates the selective extraction of aromatics from the kerosene stream.
• Purpose: The main objective of reducing aromatics in kerosene through the Edeleanu process is to improve the product quality by reducing the potential for smoke formation during combustion and meeting regulatory specifications for aviation fuels and other applications where low aromatic content is preferred.

Therefore, in the Edeleanu process, the extractor temperature of -20°C is specifically chosen to effectively reduce the aromatic content of kerosene, enhancing its quality and performance characteristics. The Edeleanu process is a type of extraction process in the petroleum refining industry, whereby liquid sulfur dioxide is used to extract aromatics from kerosene pool, liquid SO₂ selectively dissolves the aromatics leaving behind the low aromatic content kerosene as the finished product. It is named after the Romanian chemist of Jewish origin Lazar Edeleanu. The aromatic extract is then separated from SO₂ through rectification and SO2 recirculation. Temperature is maintained at -20°C.