ExxonMobil: New Zeolite Cuts Ethylene Extraction Costs

ExxonMobil and the Institute of Chemical Technology (ITQ) in Spain have discovered a new silica zeolite that cuts down the cost of extracting ethylene from ethane, the US-based producer said on Thursday.

The new material is patented and called ITQ-55, ExxonMobil said. When used with other separation processes, ITQ-55 can result in reductions of up to 25% in the energy used in ethylene separation as well as the carbon dioxide (CO2) associated with it.

Ethylene extraction is an energy-intensive process because it relies on cryogenic distillation. The new material saves so much energy over cryogenic dstilliation because it relies on absorption, an entirely different process. Moreover, ITQ-55 selectively absorbs ethylene over ethane.

This preference is due to the material's flexible pore structure, a feature that ExxonMobil has called unique. This structure allows ITQ-55 to act like a flexible molecular sieve, allowing the diffusion of flatter ethylene molecules as opposed to the more cylindrical-shaped ethane ones.

As such, the material absorbs ethylene and filters out ethane, said Avelino Corma, a professor of the institute and a co-author of the research in the material.

Although ITQ-55 holds promise, it still needs more research before larger scale demonstration and commercialisation can be considered, ExxonMobil said. Future research will focus on incorporating ITQ-55 into a membrane and developing more materials for gas separation.

The results of the research were published in the journal Science, and an abstract can be seen here.

The Institute of Chemical Technology is a joint research centre in Valencia that was created by the Universitat Politecnica de Valencia and the Consejo Superior de Investigaciones Cientificas.