In line with the Program to increase feedstock yield for butyl rubber production, Divinyl & HC Feed Plant of "Nizhnekamskneftekhim" INC launched an Isobutylene Fraction Concentration Unit ( Êò -402), which enabled to take out of service the existing two Concentration Units Êò -250 and Êò -2, and moreover, enables to keep a spare capacity for isobutylene feedstock production in future.