March 16 (Reuters) - Exxon Mobil Corp (XOM.N) has successfully started up a new $2-billion crude distillation unit (CDU) at its Beaumont, Texas refinery, said Karen McKee, president of Exxon Products Solutions on Thursday.

The new CDU adds 250,000 barrels per day (bpd) to the refinery's capacity to break down crude oil into feedstocks for motor fuels.

In a statement issued on Thursday, Exxon set the refinery's capacity at more than 630,000 bpd.

"The unit is started up and we're just ramping up rates at present, but it's operating very reliably," McKee said in a phone interview.

Exxon began the initial startup of the new crude unit in late February, people familiar with plant operations told Reuters. read more

"We're well over 200,000 bpd at this point," McKee said. "We're pushing rates right now so I would anticipate we'll get to full capacity soon."

Exxon has said it wants the crude unit to reach its full 250,000-bpd capacity by the end of March.

The Beaumont refinery expansion, built between 2019 and 2022 and which includes a new hydrotreater, allows Exxon to take advantage of crude oil it produces in the Permian Basin in Texas and New Mexico.

McKee said the Beaumont refinery is well-positioned because of "tremendous logistics in and out of the site" to supply diesel and other motor fuels from the new crude unit to U.S. or international markets.

McKee said the biggest challenge was pushing on through the COVID-19 pandemic.

"We had the courage to keep going on this project despite the many challenges both with getting work done and also demand for products and cash flow during the pandemic period," McKee said.

The new crude unit is equal in size to mid-level refinery and boosts the Beaumont refinery's capacity by 68%.