A series of amine-based adsorbents were synthesized using siliceous MCM-41 individually impregnated with four different amines（ethylenediamine（EDA）,diethylenetriamine（DETA）,tetraethylenepentamine（TEPA） and pent...A series of amine-based adsorbents were synthesized using siliceous MCM-41 individually impregnated with four different amines（ethylenediamine（EDA）,diethylenetriamine（DETA）,tetraethylenepentamine（TEPA） and pentaethylenehexamine（PEHA）） to study the effect of amine chain length and loading weight on their CO2 adsorption performances in detail.The adsorbents were characterized by FT-IR,elemental analysis,and thermo-gravimetric analysis to confirm their structure properties.Thermo-gravimetric analysis was also used to evaluate the CO2 adsorption performance of adsorbents.Longer chain amine-based materials can achieve higher amine loadings and show better thermal stability.The CO2 adsorption capacities at different temperatures indicate that the CO2 adsorption is thermodynamically controlled over EDAMCM41 and DETA-MCM41,while the adsorption over TEPA-MCM41 and PEHA-MCM41 is under kinetic control at low temperature.The chain length of amines affects the CO2 adsorption performance and the adsorption mechanism significantly.The results also indicate that CO2 adsorption capacity can be enhanced despite of high operation temperatures,if appropriate amines（TEPA and PEHA） are applied.However,adsorbents with short chain amine exhibit higher adsorption and desorption rates due to the collaborative effect of rapid reaction mechanisms of primary amines and less diffusion resistance of shorter chain length amines.展开更多
High-surface-area,hexagonal-structured mesoporous silica,MCM-41,was synthesized and wet impregnated with three different amines of 2-(ethylamino)ethanol(EAE),ethylenediamine(EDA),and tetraethylenepentamine(TEPA)for us...High-surface-area,hexagonal-structured mesoporous silica,MCM-41,was synthesized and wet impregnated with three different amines of 2-(ethylamino)ethanol(EAE),ethylenediamine(EDA),and tetraethylenepentamine(TEPA)for use as solid adsorbents in post-combustion CO_(2) capture application.The CO_(2) adsorption test was performed at 25℃and atmospheric pressure using 15/85 vol%of CO_(2)/N2 at a 20-mL/minute flow rate.Desorption was carried out at 100℃under 20 mL/minute of N2 flow.The results show that the capacity and rate of CO_(2) adsorption obtained from all the amine-modified adsorbents were significantly increased with increasing amine loading due to carbamate formation.Desorption efficiency and heat duty for regeneration were also affected by the amount of amine loading.The more stable the carbamate produced,the higher the energy was required.They exhibited the highest adsorption-desorption performance at 60 wt%amines used for impregnation.Blended EAE/TEPA at different weight ratios at a total concentration at 60 wt%amines was impregnated on MCM-41 adsorbent.Sorbent impregnated with 50%/10%of EAE/TEPA showed the best performance of 4.25 mmolCO_(2)/g at a high adsorption rate,a low heat duty of 12 kJ/mmolCO_(2) and with 9.4%reduction of regeneration efficiency after five repeated adsorption-desorption cycles.展开更多
A novel solid support adsorbent for CO2capture was developed by loading pentaethylenehexamine(PEHA)on commercially available mesoporous molecular sieve MCM-41 using wet impregnation method.MCM-41 samples before and af...A novel solid support adsorbent for CO2capture was developed by loading pentaethylenehexamine(PEHA)on commercially available mesoporous molecular sieve MCM-41 using wet impregnation method.MCM-41 samples before and after PEHA loading were characterized by X-ray powder diffraction,N2adsorption/desorption,thermal gravimetric analysis and scanning electron microscope to investigate the textural and thermo-physical properties.CO2adsorption performance was evaluated in a fixed bed adsorption system.Results indicated that the structure of MCM-41 was preserved after loading PEHA.Surface area and total pore volume of PEHA loaded MCM-41 decreased with the increase of loading.The working adsorption capacity of CO2could be significantly improved at 60%of PEHA loading and 75°C.The effect of the height of adsorbent bed was investigated and the best working adsorption capacity for MCM-41-PEHA-60 reached 165 mg·(g adsorbent)-1at 75°C.Adsorption/desorption circle showed that the CO2working adsorption capacity of MCM-41-PEHA kept stable.展开更多
基金supported by the National Natural Science Foundation of China(91434120)the Fundamental Research Funds for the Central Universities(2014ZD06),and the 111 Project(No.B12034)
文摘A series of amine-based adsorbents were synthesized using siliceous MCM-41 individually impregnated with four different amines（ethylenediamine（EDA）,diethylenetriamine（DETA）,tetraethylenepentamine（TEPA） and pentaethylenehexamine（PEHA）） to study the effect of amine chain length and loading weight on their CO2 adsorption performances in detail.The adsorbents were characterized by FT-IR,elemental analysis,and thermo-gravimetric analysis to confirm their structure properties.Thermo-gravimetric analysis was also used to evaluate the CO2 adsorption performance of adsorbents.Longer chain amine-based materials can achieve higher amine loadings and show better thermal stability.The CO2 adsorption capacities at different temperatures indicate that the CO2 adsorption is thermodynamically controlled over EDAMCM41 and DETA-MCM41,while the adsorption over TEPA-MCM41 and PEHA-MCM41 is under kinetic control at low temperature.The chain length of amines affects the CO2 adsorption performance and the adsorption mechanism significantly.The results also indicate that CO2 adsorption capacity can be enhanced despite of high operation temperatures,if appropriate amines（TEPA and PEHA） are applied.However,adsorbents with short chain amine exhibit higher adsorption and desorption rates due to the collaborative effect of rapid reaction mechanisms of primary amines and less diffusion resistance of shorter chain length amines.
基金supported by the Petroleum and Petrochemical College and the Rachadapisek Sompote Fund,Chulalongkorn University for Postdoctoral Fellowship to the first author.
文摘High-surface-area,hexagonal-structured mesoporous silica,MCM-41,was synthesized and wet impregnated with three different amines of 2-(ethylamino)ethanol(EAE),ethylenediamine(EDA),and tetraethylenepentamine(TEPA)for use as solid adsorbents in post-combustion CO_(2) capture application.The CO_(2) adsorption test was performed at 25℃and atmospheric pressure using 15/85 vol%of CO_(2)/N2 at a 20-mL/minute flow rate.Desorption was carried out at 100℃under 20 mL/minute of N2 flow.The results show that the capacity and rate of CO_(2) adsorption obtained from all the amine-modified adsorbents were significantly increased with increasing amine loading due to carbamate formation.Desorption efficiency and heat duty for regeneration were also affected by the amount of amine loading.The more stable the carbamate produced,the higher the energy was required.They exhibited the highest adsorption-desorption performance at 60 wt%amines used for impregnation.Blended EAE/TEPA at different weight ratios at a total concentration at 60 wt%amines was impregnated on MCM-41 adsorbent.Sorbent impregnated with 50%/10%of EAE/TEPA showed the best performance of 4.25 mmolCO_(2)/g at a high adsorption rate,a low heat duty of 12 kJ/mmolCO_(2) and with 9.4%reduction of regeneration efficiency after five repeated adsorption-desorption cycles.
基金Supported by the National Natural Science Foundation of China(20836008,21176132)the Special Research Fund for the Doctoral Program of the Ministry of Education of China(20101012174)
文摘A novel solid support adsorbent for CO2capture was developed by loading pentaethylenehexamine(PEHA)on commercially available mesoporous molecular sieve MCM-41 using wet impregnation method.MCM-41 samples before and after PEHA loading were characterized by X-ray powder diffraction,N2adsorption/desorption,thermal gravimetric analysis and scanning electron microscope to investigate the textural and thermo-physical properties.CO2adsorption performance was evaluated in a fixed bed adsorption system.Results indicated that the structure of MCM-41 was preserved after loading PEHA.Surface area and total pore volume of PEHA loaded MCM-41 decreased with the increase of loading.The working adsorption capacity of CO2could be significantly improved at 60%of PEHA loading and 75°C.The effect of the height of adsorbent bed was investigated and the best working adsorption capacity for MCM-41-PEHA-60 reached 165 mg·(g adsorbent)-1at 75°C.Adsorption/desorption circle showed that the CO2working adsorption capacity of MCM-41-PEHA kept stable.
