Nigerian billionaire Aliko Dangote said he’s on schedule to finish by next year his $15 billion oil refinery, which will be one of the world’s biggest, despite analysts saying the timeline is ambitious.

“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 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 the refinery’s products, while the rest will serve the local market. His Dangote Industries Ltd. said last year the plan is to produce about 50 million liters (13.2 million gallons) a day of gasoline and 15 million liters of diesel, though output can be changed according to demand. The company has been in talks with oil traders including Royal Dutch Shell Plc, Vitol Group and Trafigura Group Pte about them supplying crude and buying refined fuel.

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

The complex will include a $2.5 billion fertilizer factory with a capacity of 3 million metric tons annually, set to be ready 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, also costing Dangote about $2.5 billion.

“By next year, we’ll be exporting almost 2 million metric tons of urea and ammonia,” Dangote said. (Bloomberg)