Systems and methods are provided for performing field enhanced separations on a feed, such as a petroleum feed, a refinery feed, or another type of hydrocarbonaceous feed. The system can allow for increased throughput of feed per volume of the separation device or system while performing a desired amount of field enhanced separation. The field enhanced separation can include separation by thermal diffusion, optionally enhanced by the presence of an electric field in the channel for performing the separation by thermal diffusion.