Complex sentence: Frontier Oil owns refineries in Cheyenne, WY and El Dorado, KS.The Cheyenne refinery is a 52,000 bpd capacity refinery and the El Dorado refinery is a 110,000 bpd capacity refinery.
Split into simpler sentences: Frontier Oil owns refineries in Cheyenne, WY and El Dorado, KS. Cheyenne Refinery is a 52,000 bpd capacity refinery and El Dorado Refinery is a 110,000 bpd capacity refinery.