Is there a "best" heavy fuel for partial oxidation [PO]? How do you define "best" ?
The main advantage of PO is that it can operate on low-priced heavy fuels and supplies hydrogen at such pressures capable of reducing the compression costs in hydrocrackers and ammonia plants.
Please note that when the PO process is done with oxygen, air liquefaction would be normally required.
Besides, the dry gas produced in this case is a mixture (90%+) of CO and hydrogen plus small amounts of CO2, CH4, N2, Ar, H2S, COS. This gas undergoes a shift reaction and other purifications.