Imports In 2014, Montenegro imported $157 in Butene (butylene) and isomers thereof, becoming the 0th largest importer of Butene (butylene) and isomers thereof in the world. At the same year, Butene (butylene) and isomers thereof was the 0th most imported product in Montenegro. Montenegro imports Butene (butylene) and isomers thereof primarily from: N/A.