Disclosed is a system of making an olefin derivative from a dilute olefin feed. Dilute olefin (1) is sent to an olefin reaction unit (3) to form an olefin derivative product. The olefin derivative product (4) is recovered from the reaction unit while a vent stream (5) is also removed. A portion of the vent steam may be recycled back to the reaction unit via line (9). The vent stream is sent to an olefin separation unit (6), where an olefin stream (7) is recovered and returned to the olefin reaction unit for additional processing. The non-olefin compounds are removed via purge (8). Using appropriate recycle of vent gas within the olefin reaction unit allows the use of a high quality olefin stream in the olefin reaction process with a reduced risk of equipment fouling and catalyst contamination, while maintaining a high product quality.
