Butadiene, C4H6 - also known as 1,3-Butadiene, is a simple conjugated diene. It is mainly derived using an extractive distillation process from the Crude C4 stream. Most Butadiene is polymerized to produce Styrene-Butadiene Rubber (SBR), which is used in manufacturing automobile tires. Other uses include manufacturing adhesives, sealants, coatings, and rubber articles like shoe soles.

Raffinate-1 is a by-product of the process of extractive distillation of Crude C4. Crude C4 contains 55-60% of Raffinate-1, while the other portion is Butadiene. Raffinate-1 consists of Isobutylene, Butene-1, Butene-2 and small amounts of Butanes and other compounds. Isobutylene is the primary feedstock to manufacture Methyl Tertiary Butyl Ether (MTBE) and Di-isobutylene (DIB).