By Reuters Staff 1 Min Read FILE PHOTO: A view of the Exxon Mobil refinery in Baytown, Texas September 15, 2008. REUTERS/Jessica Rinaldi HOUSTON (Reuters) - Production at the restarted Exxon Mobil Corp 369,024 barrel-per-day (bpd) Beaumont, Texas, refinery is being hampered by reduced coker throughput, said sources familiar with plant operations. The 45,000-bpd coker has been operating at varying production levels since restarting earlier this week, the sources said. Exxon spokesman Jeremy Eikenberry declined to discuss the status of individual units at the Beaumont refinery. “Exxon Mobil continues to make progress restarting operations at its Beaumont refinery,” Eikenberry said. The coker converts residual crude oil from distillation units into motor fuel feedstocks or petroleum coke, a substitute for coal.