An industrial scale heptane hydroisomerization process was simulated based on a concept of two reactors and a zeolite membrane. A product stream containing tribranched, and part of the dibranched C-7 isomers with octane number up to 92 is predicted. The economics of the process shows an investment cost of 40 million euros, with the membrane unit as the main cost driver. The technical and economical feasibility of this industrial scale heptane hydroisomerization process depends mainly on further development and performance of zeolite membranes. (c) 2004 Elsevier B.V. All rights reserved.