Active Ceramic Membranes
Active Ceramic Membranes Enable High-Value Chemical Conversions
At sufficient temperatures, specific compositions of zirconia and other advanced technical ceramics can transport ions — allowing them to act as selective ion transport ceramics at a molecular level. Active ceramic membranes can be applied to a growing variety of solid oxide electrolysis (SOXE), gas-to-chemicals (GTCh), and gas-to-liquids (GTL) conversion applications.
CoorsTek continues to develop this remarkable capability, and to work with key global partners through CoorsTek Membrane Sciences and Ceramatec (a CoorsTek R&D company) to push the frontier of materials science in active ceramic membranes.
Direct Natural Gas Conversion
CoorsTek has developed a new process to use natural gas (methane) as raw material to produce high-value aromatic chemicals. The process uses an advanced ceramic membrane engineered to make the direct, non-oxidative conversion of gas to liquids possible for the first time — reducing cost, eliminating multiple process steps, and avoiding any carbon dioxide (CO2) emissions. The resulting aromatic precursors are source chemicals for insulation materials, plastics, textiles, and jet fuel, among other valuable products.
The co-ionic ceramic membrane intensifies the methane dehydroaromatization (MDA) process by simultaneously extracting hydrogen (H2) and injecting oxygen species — making MDA technology viable by improving yields, extending catalyst stability, and eliminating CO2 emission.
Direct activation of methane, the main component of biogas and natural gas, has been a key goal of the hydrocarbon research community for decades. This new process is detailed in the August 5, 2016 edition of Science, in a research paper entitled “Direct conversion of methane to aromatics in a catalytic co-ionic membrane reactor”.
Watch a video that explains the breakthrough natural gas to liquids conversion process.
Mars Mission and SOXE
In Solid Oxide Electrolysis (SOXE), for example, Ceramatec oxygen transport membrane (OTM) technologies take advantage of zirconia’s ion-conducting properties to create a flow of oxygen ions from an air source at a cathode across the electrolyte membrane to an anode.
When the O2- ions reach the anode, they release electrons as they combine with the fuel (e.g. CO and H2). These electrons then flow in an electrical current, directly creating usable electrical power rather than requiring a heat engine to convert the energy.
The process can also be reversed. CoorsTek R&D company Ceramatec is working with NASA on the MOXIE project for the 2020 Mission to apply its active ceramic membrane technology to generate high-purity oxygen (O2) from the abundant, indigenous carbon dioxide (CO2) in Mars' atmosphere.
Creating Pressurized Pure Oxygen
CoorsTek, through its R&D company Ceramatec, has developed a Solid Electrolyte Oxygen System (SEOS) for the generation of 99.999% pure oxygen that can be used to fill oxygen tanks for medical applications, or anywhere high-purity oxygen is required.
SEOS generators produce oxygen that is separated from feed air supplied at ambient temperature and pressure and compressed using a heated, non-porous ceramic membrane that conducts oxygen ions through its crystal lattice. Electricity then provides the driving force to produce oxygen at elevated pressure for the final application.
Sodium Ion Based Alternatives to Batteries
In a similar fashion, NaSICON (sodium - Na Super Ionic CONductor) is a Na-ion selective membrane. The ceramic membrane cell operates at > 95% transfer efficiency to make Alkali (Na) salts from various sodium organic and inorganic based aqueous and non-aqueous sources. NaSICON cells do not rely on the same, highly reactive chemicals that lithium ion batteries do, making them inherently safer. By using inexpensive and abundant sodium, NaSICON cells can outperform lithium-ion batteries, which require expensive Lithium, at a lower cost.
NaSICON is also useful in applications of pure Na metal production, removal of Na ions from various waste streams, and heavy oil upgrading technologies.