How is high-purity isopentane produced and what purity levels are available?

How is high-purity isopentane produced and what purity levels are available?
High-purity isopentane is manufactured mainly by distillation or adsorption. Distillation typically uses a two-column setup, either de-C4 first then de-C5+, or the reverse, and requires significant capital investment. Adsorption routes are longer and more energy-intensive during desorption. A typical multi-column continuous distillation design can achieve isopentane purity of 99% or higher with recovery above 99%, using double-effect heat integration to cut energy use by 25-30%. The Chinese industry standard HG/T 5613-2019 classifies industrial-grade, polymer-grade and high-purity grades. Polymer-grade material, used as a chain transfer agent and catalyst solvent in gas-phase PE/PP production, demands ppm-level impurity control. High-purity isopentane also serves as a blowing agent for EPS and PU foam, a refrigerant, and a feedstock for dehydrogenation to isopentene and isoprene.