NGL volumes continue to climb because of all the surging “wet” shale gas production. These days about 7% of gas plant NGL production is “isobutane”, (also known as IC4, I Grade, methylpropane, R600a, iso and “izo” to our friends in Canada). Over the past two years gas plant production of iso is up about 25%, and that volume is expected to increase another 30% over the next two years. Most isobutane is used by refineries to make high-octane alkylate, but what about the rest? Today we take a closer look at this lesser known natural gas liquid (NGL) and the sometimes exotic uses it is put to.