The invention relates to a system for separating substances in a substance mixture. The system comprises a radiation source and a separation column. The separation column comprises at least a first section, the first section comprising at least a first subsection and a second subsection. The radiation source is configured to radiate electromagnetic radiation in the direction of the first section to heat the first section, wherein the electromagnetic radiation comprises infrared radiation. The electromagnetic radiation is receivable in the first subsection of the separation column with a higher intensity than in the second subsection of the separation column, so that the first subsection is heatable more intensively than the second subsection and a temperature gradient can be formed at least in sections along the first section (21) of the separation column (20).