| The essences of removing CO2 by chemisorption is to use alkaline absorbent mixed with CO2 in the flue gas, and react to form volatile salts, the salts will revers decomposition under certain conditions to regenerate for releasing CO2, which to achieve the separation of CO2 and flue gas. So far, the dry absorption with the advantage of low energy consumption, high recycling efficiency, no corrosion to equipment and no secondary pollution has become a research hotspot. This paper studies the preparation of the dry sorbent and the analogue regenerant of the sorbent, to simulate the regenerable characteristic and the dynamics characteristic of analogue regenerant.Through comparative analysis, Suzhou Creek river sediment is chosen as the support of dry absorbent for CO2 capture, and the river sediment is researched by thermal gravimetric analyzer. Results of experiments show that there are three main stages of untreated river sediment thermal decomposition, it is respectively the dehydration stage, the organic carbon pyrolysis stage and the calcination stage. Analysis by SEM and nitrogen adsorption analyzer, compared with the surface morphology, pore structure and surface area, pore volume and pore size to devision monoclinic system K2CO3 and hexagonal K2CO3 that was generated by thermal decomposition of KHCO3. In the final selection, KHCO3 and hexagonal K2CO3 were determined to be the active component of dry absorbent for CO2 capture and the analogue regenerant of potassium-based sorbents. Na2SiO4 was used to be binder, and Guangxi plastered as additives in this paper. After some treatment of the sediment, adding into the binder and additives in accordance with the appropriate proportion and fully mixed with the active component, the analogue regenerant of dry sorbents were prepared after forming ballstye particle. And the dry sorbents for CO2 caputure would be obtained after thermal decomposition. The surface morphology, microstructure and specific surface area was analyzed By scanning electron microscopy (SEM) and surface area analyzer in this paper. TGA experiments of chemically pure KHCO3 was studied at standard conditions and different final temperature of decomposition conditions, results show that, decomposition of KHCO3 would be completed with one step, and it mainly occurred between 100℃～200℃. The best final temperature is about 200℃.The regenerant was studied by thermogravimetric analysis on the loading of potassium bicarbonate, the heating rate and the addition of potassium carbonate, to investigate the regenerable characteristic and dynamics characteristic. Experimental and analytical results show that the the maximum conversion rate was 96.67% when the potassium bicarbonate loading was 40%-50%, the reaction shifted to high temperature when potassium bicarbonate loading was increased. Changes of heating rate was an invisible effect to regenerable reaction,and the regenerable conversion exceeding 90% when heating rate was more than 5℃/min. There were two peaks for DTG curves when KHCO3 and K2CO3 in a state of coexistence, and the two steps were located at 60～130℃and 130～220℃. The temperature range of 60～130℃was the step that removing crystal water, because K2CO3 would become K2CO3·1.5H2O easily for hygroscope. The temperature range of 130～220℃was regeneration reaction stage, the DTG curves moved to high temperature direction, the maximum conversion rate become lower significantly, and the difficulty of regenerable reaction increased. The value of the apparent activation energy of regenerable about potassium-based/river channel sediment supported sorbent for CO2 capture was between 90～110 kJ/mol Sediment load simulations of K+-based absorbent agent to be recycled for the regeneration of the apparent activation energy 90～110 kJ/mol. The value of the apparent activation energy was the lowest when KHCO3 loading was 40%, the value would increase with the heating rate higher, and it increased slightly when K2CO3 was added into the active component.
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