(479g) Comparing Capital Cost and Power Consumption between Cryogenic Distillation and Membrane Cascades for Ethane/Ethylene Separation

Ethylene is one of the most versatile and widely used petrochemicals in the world. The separation of ethane/ethylene is of prime importance in the production of polymer-grade ethylene for industrial manufacturing. Because of the energy-intensive nature of the separation, the growing concern for reducing carbon dioxide emissions has led to intense research about the energy-efficient separation processes.

Here we will present our results comparing power consumption and capital cost of the two separation processes on an equivalent basis for two different plant sizes. To compare cryogenic distillation and membrane cascade on an equivalent basis, we need to use state-of-the-art processes for each of the two separation processes. Therefore, 1) we will first briefly present a novel energy efficiency cryogenic distillation process; 2) then discuss a Mixed Integer Non-linear Program (MINLP) for binary membrane separations; and 3) finally, we will present power consumption and capital cost of the cryogenic distillation and the membrane cascades under different performance specifications of product purity and recovery, and membrane permselectivity and permeability parameters.

Our results will provide useful insights into the performance of each of the methods on an equivalent basis. For membranes, our methodology provides valuable benchmarks for permeance, perm-selectivity, and lifetime values needed for the ethane/ethylene separation membranes.