(Bloomberg) -- Nigerian billionaire Aliko Dangote said he’s on schedule to finish his $15 billion oil refinery, which will be one of the world’s biggest, by next year.

“There are quite a lot of challenges, but we’re moving,” Dangote told reporters at a conference in Paris about the plant, which is being built near Lagos, Nigeria’s commercial capital, and is designed to process 650,000 barrels of crude daily. “We’re still targeting next year for commissioning.”

The 61-year-old said he will export about 35 percent of what the refinery produces.

Analysts have questioned whether Dangote, worth $10.8 billion according to the Bloomberg Billionaire’s Index, will be able to finish such a massive project on time and within costs. Edinburgh-based Wood Mackenzie doesn’t see the refinery starting production until 2022.

READ: A $15 Billion Oil Bet Is Tough Challenge for Richest African

The complex will include a $2.5 billion fertilizer factory, set to be completed this year, and a petrochemical plant. They will be powered by gas, which will be sent from the Niger River delta via two 550-kilometer (341-mile) underwater pipelines, which will also cost Dangote about $2.5 billion.

--With assistance from Paul Wallace.

To contact the reporter on this story: Francois de Beaupuy in Paris at fdebeaupuy@bloomberg.net

To contact the editors responsible for this story: Dana El Baltaji at delbaltaji@bloomberg.net, Sophie Mongalvy

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