Template Technique for Synthesis of CaO-based Sorbents
9th International Mesostructured Materials Symposium (IMMS9)
17-20 Aug 2015
|| Derevshhikov Vladimir Sergeevich
, Semeykina Viktoriya Sergeevna
, Bitar Jasmine
, Parkhomchuk Ekaterina Vasilievna
, Okunev Aleksei Grigorʹevich
Boreskov Institute of Catalysis SB RAS
Novosibirsk State University
Emissions of large amounts of CO2 to the atmosphere, mostly as a by-product of burning fossil fuels in man-made processes, are contributing to climate change. Among the options for reducing greenhouse gas emissions there is CO2 capture from the large stationary sources. It was proposed in many works to use calcium-based sorbents for effective CO2 capture from gases at high temperatures. It is well known that textural properties drastically effects to sorption/regeneration performance of sorbent during cycles under the conditions of CO2 capture process . Different methods involving direct thermal decomposition of the,
Ca-containing precursors, wet chemistry, sol-gel technique and flame pyrolysis, were applied to modify porous structure of Ca-based sorbents. In mentioned cases porosity and pore size distribution are regulated by chemical nature of precursors and conditions of experiment. In parallel with interest growing to CaO-sorbents novel template approach started emerging and developing. In general this technique consists of two steps: at first step the template particles with definite shape and size are introduced to matrix media. After that
matrix material solidifies and template is deleted. Thus, template synthesis with nanocasting is a direct technique for design materials with appropriate porosity and pore size distribution . We have used template approach to introduce additional porosity in CaO-based sorbents and to arrange theirs pore size distribution. The effect of synthetized sorbents porous structure on their sorption performance during repetitive carbonation/regeneration cycles was investigated.
The pore size distribution of prepaid sorbents drastically depends on the quantity and the size of introduced template, but also on the sorbent preparation conditions. The introducing of template significantly increases the rate both of sorbent carbonation and calcination reactions.
of sorbent with template for more than 1 order of magnitude in comparing with the pure
sample without template. In this way template approach seems to be a perspective technique
to prepare the CaO-based sorbents with better carbonation/calcination performance  it is
also a subsequent development and improvement of synthesis technique required.
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