According to an embodiment of the present disclosure, petrochemicals may be produced from crude oil by a process which includes passing the crude oil and hydrogen into a hydroprocessing reactor, separating the hydrotreated oil into a lesser boiling point fraction and a greater boiling point fraction, passing the lesser boiling point fraction to a pyrolysis section of a steam cracker to produce a pyrolysis effluent comprising olefins, aromatics, or both, passing the greater boiling point fraction to a gasifier, where the gasifier produces hydrogen, and passing at least a portion of the hydrogen produced by the gasifier to the hydroprocessing reactor.