Zeolites have an enormous impact on our daily lives, both directly and indirectly. Zeolites are used in the production of petrochemicals, fuels, biogas, water purification, as well as household products like cat litter, disposable nappies, clothes, furniture, foods and construction materials. Zeolites have microporous structures which gives them excellent attributes as adsorbents or catalysts.
At C-Tech, our interest in zeolites is currently focussed on their use as catalysts in the production of biofuel, as part of the FP7-funded project BIOGO. BIOGO is a €12.3M collaborative European project between fifteen partners from seven countries, who together intend to create a fully integrated and comprehensive process for the production of biofuels using novel nanocatalysts, innovative micro-reactor technology and sustainable resources.
As part of our involvement in the BIOGO project, we are trying to optimise thin film coatings on the zeolite structures that will benefit selectivity and efficiency in the production of biofuel. Different methods and ‘recipes’ for coatings are being trialled at C-Tech to identify coatings that exhibit anti-coking properties, thereby extending the life of the catalyst.
In developing these thin film coatings, we are interested in their surface structure: as the higher the surface area the larger the number of reaction sites and so the greater the potential for catalytic activity. The distribution of the different chemical elements in our coatings that have catalytic and anti-coking effects is also of interest as, ideally there would be a uniform distribution to maximise their influence in a biofuel reactor. To see whether the coatings we are producing have a good surface structure and distribution of chemical elements, we sent samples of iron and chromium-doped zeolites to BIOGO project partners at the University of Warwick to analyse in their imaging suite.
Low-magnification image of the iron-zeolite material.
Scanning electron microscope images of C-Tech thin film zeolite coatings were captured showing the surface structures to be cubic polycrystallites, i.e. composed of multiple crystals of varying size (3-6 µm) and orientation. The elemental analysis conducted showed that the composition expected was observed, though at very low levels for the instruments to detect.
High-magnification image of the iron-zeolite material.
There are still two and a half years remaining of the BIOGO project and at C-Tech we will be spending this time refining our methods of producing thin film coatings and optimising the functionality of these films for the biofuel production process.