The invention relates to a process and an apparatus for producing an olefin-containing feed stream for a steam reforming plant. According to certain embodiments of the invention, the olefin-containing hydrocarbon starting material is for this purpose vaporized and catalytically hydrogenated. The hydrogenation product stream obtained is separated into a gaseous reforming feed stream, which is fed to a steam reforming plant, and a gaseous recycle stream. As a result of the cooling according to the invention of the gaseous recycle stream down to at least partial condensation thereof and the separate recirculation of the gaseous partial recycle stream and of the liquid partial recycle stream, the procurement of a large and complicated circulation compressor is avoided and electric energy for operating this compressor is saved.