A process for converting ethane to liquid fuels may involve directing an ethane stream into an ethane cracking unit to produce an intermediate hydrocarbon stream and a raw ethylene stream; fractionating the intermediate hydrocarbon stream into a gasoline fraction and a diesel fraction; introducing the raw ethylene stream into an oligomerization unit; contacting the raw ethylene stream with an oligomerization catalyst to produce a liquid hydrocarbon stream and an off-gas stream; recycling an off-gas recycle stream from an off-gas stream of the oligomerization unit separation unit to an inlet of the oligomerization reactor; introducing at least part of the off-gas stream into a hydrogenation reactor to remove unconverted olefins; separating a hydrogen component and a plurality of light paraffin components in a post hydrogenation reactor separation unit using a PSA technology or membrane technology; and recycling the light paraffins stream into the ethane cracking unit.