Asia's oldest refinery Digboi Refinery is situated in upper Assam district of Tinsukia. A century ago just before the World War I, history of another kind was in the making in a remote corner of Assam in the midst of the dense and malaria infested jungles by a band of intrepid pioneers searching for black gold.
The Digboi Refinery is located in Digboi town in Tinsukia district in the north-eastern part of the state of Assam, India. It is located at 27°22'48.0"N 95°37'48.0"E. It has an average elevation of 165 metres (541 ft).It is situated 510 km north east of Guwahati.
The Digboi Refinery was set up at Digboi in 1901 by Assam Oil Company Ltd.. It has the distinction of being Asia's first refinery and one of oldest still in operation. Oil was accidentally discovered in 1867 while laying a railway line in Digboi area. It was just found seeping out in dense jungles in Tinsukia district. Digging for oil was started in 1889 and the refinery set up in 1901 at Digboi.
Digboi Refinery has crude processing capacity of 0.65 MMTPA. It processes waxy crude extracted from oil fields operating in area nearby Digboi. It has also started processing of Crude condensate in 2018. Digboi Refinery was modernized with commissioning of new CDU, DCU, CRU towards end of 1990s. In early years of 21st century, new units SDU, WHFU, HDTU, HGU, SRU and Captive Power Plant were commissioned. Later on, Digboi Refinery commissioned MSQU units NHT and ISOM units in 2010. The refinery also has Wax Moulding unit and Wax Pelletisation unit for production of finished Wax in Slab and Pellet form respectively. It has also installed and commissioned a CRMB+ unit in 2018 for production of Crumb Rubber Modified Bitumen using IOCL-R&D developed technology.