Which refiners are least CO2 intensive, and which refiners are most CO2 intensive? This spreadsheet answers the question, by aggregating data from 130 US refineries, based on EPA regulatory disclosures.
The full database contains a granular breakdown, facility-by-facility, showing each refinery, its owner, its capacity, throughput, utilisation rate and CO2 emissions across six categories: combustion, refining, hydrogen, CoGen, methane emissions and NOx (chart below).

Assessed companies include Aramco, BP, Chevron, Citgo, Delek, ExxonMobil, Koch, Hollyfrontier, Marathon, Phillips66, PBF, Shell and Valero.