Africa's biggest refinery is getting bigger.Nigeria's Dangote refinery has started work on a second crude processing unit that will add another 700,000 barrels per day (bpd) of capacity, putting the complex on track to rival the world's largest refining site and giving billionaire owner Aliko Dangote a much larger role in global fuel markets.According to Dangote Petroleum Refinery CEO David Bird, construction is already underway at the Lekki site outside Lagos. The new refinery is expected to be online by the end of 2028 and would lift total processing capacity at the complex to roughly 1.4 million bpd.The announcement appears to be a more detailed version of the expansion plans Dangote outlined earlier this week, when executives said the company was targeting mechanical completion of a second crude distillation unit by late 2028.The existing 650,000-bpd refinery has already become one of the most closely watched refining assets in the world. After reaching near-full utilization this spring, the facility helped turn Nigeria into a net gasoline exporter for the first time while simultaneously shipping large volumes of jet fuel to Europe amid refinery outages, low inventories, and war-related supply disruptions.At one point this spring, Dangote was exporting roughly 100,000 bpd of jet fuel, with Europe absorbing about half of those volumes.The refinery's growing influence has been particularly visible during the Middle East supply crisis. While many fuel-importing nations scrambled for barrels, Nigeria found itself unusually insulated thanks to rising domestic refining capacity.Bird said the company plans to expand its trading business alongside the refinery buildout. Additional export flows from Nigeria, combined with potential plans for a second refinery in East Africa, could dramatically increase the group's presence in international fuel markets.Kenyan officials have already indicated that Dangote is exploring a refining project there. If both projects move forward, the group's total processing capacity could approach 2 million bpd.That would place Dangote in the same league as the world's largest refining players and turn what began as a solution to Nigeria's fuel import problem into a major force in global petroleum trade.By Julianne Geiger for Oilprice.comMore Top Reads From Oilprice.comHouse Passes War Powers Measure on Iran, But Trump Will Likely Kill ItIranian, Russian Crude Premiums Slide as China Pulls Back on ImportsSouth Korea Boosts Jet Fuel Exports to Nine-Month High