Digboi refinery is known as the birthplace of the oil Industry in India. It was commissioned on 11 December 1901. It has the distinction of being Asia’s first refinery and the oldest still in operation.

Earlier owned and operated by the Assam Oil Company Limited/Burmah Oil Company, it came into the fold of the Indian Oil Corporation Limited and became the Assam Oil Division of Indian Oil Corporation Limited.

Its initial capacity was 0.028 MMTPA, which was increased to 0.5 MMTPA in 1940. Subsequently, Digboi Refinery was modernized in phases and its capacity was augmented to 0.65 MMTPA in 1996. A number of new units have been commissioned which include a new Crude Distillation Unit, a new Delayed Coking Unit, a Catalytic Reforming Unit, a new Solvent De-waxing Unit, and a Wax Hydro finishing Unit. The refinery has also installed a Hydrotreater Unit in 2003 to improve the quality of diesel.

Digboi refinery processes High Wax Content Crude and produces Paraffin Wax in addition to distillates and other heavy ends. This is the only refinery in North East having the facility to produce high-quality Paraffin Wax. Relocation of the Wax Pellatization Unit from BR to DR was done in 2013.

According to indianexpress/ iocl