Exxon refinery restarts hydrocracker after CDU restart 3/5/2021 ExxonMobil Corp. has begun restarting the hydrocracker at its 560,500 barrel-per-day (bpd) Baytown, Texas, refinery, shortly after restarting a crude distillation unit (CDU), said sources familiar with plant operations. The 135,000-bpd Pipestill 7 CDU was the first to restart since the Baytown refinery was shut on Feb. 15 by the effects of severe cold weather. The 25,000-bpd hydrocracker produces diesel and other motor fuels. “Exxon Mobil continues to make progress restarting its Baytown operations,” said company spokesman Jeremy Eikenberry. Pipestill 7 is the second largest of the refinery’s three CDUs, which break down crude oil into hydrocarbon feedstocks for all other production units.