Ethylene Oxide


Ethylene Oxide is formed by reacting ethylene with oxygen over an Ethylene Oxide catalyst. The main competing reaction is the combustion of ethylene to CO2 and water. There is also a consecutive combustion reaction where Ethylene Oxide further reacts to the combustion products (see reaction figure - right, top).

The goal of Ethylene Oxide catalysis is to maximise the primary reaction (K1) while minimising or eliminating the competing and consecutive reactions, K2 and K3. CRI has been working in the area of Ethylene Oxide catalysis for more than 40 years, constantly and consistently improving catalyst performance.

The most important measure of Ethylene Oxide catalyst performance is selectivity-defined as the molar yield of Ethylene Oxide produced per molar quantity of ethylene reacted. Another important parameter is activity, the catalyst temperature required to achieve a desired Ethylene Oxide production level. CRI’s scientists have focused on improving not only the initial selectivity performance of our Ethylene Oxide catalysts, but also the average catalyst selectivity throughout life.

CRI’s long-term success is built on a series of revolutionary scientific breakthroughs that have defined Ethylene Oxide catalysis for over 40 years. CRI currently offers Ethylene Oxide catalysts in four different families (see graph - right, bottom), all of which were first invented by CRI, clearly marking CRI as the world’s undisputed Ethylene Oxide catalyst technology leader.

CRI remains active in developing, testing, demonstrating, and marketing future generations of industry-leading catalysts. Our goal remains the same as it has always been - to be the undisputed leader in providing superior Ethylene Oxide catalyst products to the global Ethylene Oxideindustry.

High activity catalyst

CRI’s High Activity (HA) catalyst family has been in existence since the 1960s. An R&D breakthrough in 1972 led to the development of the modern HA catalyst. With many improvements over the years, CRI has a long history in providing HA catalysts to the Ethylene Oxide marketplace.

CRI HA catalysts offer exceptional initial catalyst activity and long-term stability at reasonable selectivities. With many more than 300 charges of HA catalysts started up and operated all over the world, CRI is an industry leader in this catalyst family technology. However, with the invention of more selective catalysts by CRI, HA catalysts are typically only used by older Ethylene Oxide processes that cannot take advantage of more modern catalyst families.

High selectivity catalyst

CRI revolutionised the Ethylene Oxide industry when our first High Selectivity (HS) catalyst was introduced in 1987. HS catalysts offer superior selectivity compared to HA Catalysts, leading edge catalyst technology, and efficient plant operation.

HS catalysts have saved the industry thousands of kilotons in reduced ethylene consumption and reduced CO2 emissions. Over 25% of the world’s Ethylene Oxide is made over CRI’s HS catalysts. With many more than 200 charges of HS catalyst operated and more than 20 years of operational experience, CRI is the unparalleled leader in HS catalyst technology.

Hybrid catalyst

While HS catalysts offer outstanding economic performance to customers, process constraints in some plants limit their use. Therefore, CRI scientists embarked upon an ambitious R&D program designed to unite the best features of both the HA and HS catalysts into a single catalyst. The result? CRI’s “Hybrid” (HY) Catalyst Family.

These catalysts feature much higher selectivity than HA catalysts, while retaining better long-term activity and stability than HS catalysts. Introduced in 2002, HY catalysts have quickly become accepted in the marketplace, with more than 60 commercial charges in operation. Once again, CRI has demonstrated its technical leadership in delivering winning technology to the marketplace.

High performance catalyst

The scientists at CRI were not content with a HY catalyst that was a “better” HA catalyst. They have continued to work on improving HY catalysts to compete with the best performance of HS catalysts. CRI is proud to announce the invention of a fourth catalyst family, the High Performance (HP) family of Ethylene Oxide catalysts.

HP catalysts have initial selectivities approaching or in some cases equaling HS catalyst performance. HP catalysts feature the high stability of HA and HY catalysts, making them the longest lived, highest selectivity catalysts available in the world. First demonstrated on a small scale in 2005, CRI’s HP catalyst family is now poised once again to recalibrate what defines a world-class Ethylene Oxide catalyst.

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CRI Catalyst Company LP, with its global resources in research and development (R&D), manufacturing, and surface and materials science is a highly desirable partner in custom catalyst development.

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