Technology

C5 Pygas processed in the CPD Dimerization Unit is fractionated into DCPD and Isoprene-enriched C₅ Cut, that can be sent either to an Extraction Plant for Isoprene Recovery or to a Hydrogenation Plant. The DCPD Process has the flexibility to cope with varying Product targets; for CPD conversions of 85 to 90%, DCPD purity is 83%. In the same Unit, a DCPD of 91-92% is obtained by limiting the CPD conversion to 50-60%. A Unit put on stream in 1991 produces both 83% and 92% purity DCPD depending on the application. After the CPD separation step, the remaining C₅ Cut is concentrated in Isoprene and Pentadiene enriched C₅ Cut and can be sent to an Extractive Distillation Unit. There, an Isoprene-Pentadiene Stream is removed from the C₅ Olefins and Paraffins. Isoprene and Pentadiene can then be separated by Superfractionation.