The latest development on amine functionalized solid adsorbents for post-combustion CO_(2)capture:Analysis review

Global warming and associated global climate change have led to serious efforts towards reducing CO_(2)emissions through the CO_(2)capture from the major emission sources.CO_(2)capture using the amine functionalized adsorbents is regard as a direct and effective way to reducing CO_(2)emissions due to their large CO_(2)adsorption amount,excellent CO_(2)adsorption selectivity and lower energy requirements for adsorbent regeneration.Moreover,large number of achievements on the amine functionalized solid adsorbent have been recorded for the enhanced CO_(2)capture in the past few years.In view of this,we review and analyze the recent advances in amine functionalized solid adsorbents prepared with different supporting materials including mesoporous silica,zeolite,porous carbon materials,metal organic frameworks(MOF)and other composite porous materials.In addition,amine functionalized solid adsorbents derived from waste resources are also reviewed because of the large number demand for cost-effective carbon dioxide adsorbents and the processing needs of waste resources.Considering the importance of the stability of the adsorbent in practical applications,advanced research in the capture cycle stability has also been summarized and analyzed.Finally,we summarize the review and offer the recommendations for the development of amine-based solid adsorbents for carbon dioxide capture.

Synthesis of amine-pillar[5]arene porous adsorbent for adsorption of CO_(2)and selectivity over N_(2)and CH_(4)

A novel amine-modified pillar[5]arene bonded porous silica adsorbent(DETA-P5S)was designed to be applied to dynamic CO_(2)adsorption and selective separation of CO_(2)over N_(2)and CH_(4)gases mixture.The results demonstrated that reasonable introduction of DETA into the BE-P5 bonded silica support has sig nificantly increased the adsorption capacity of CO_(2).The DETA-P5S has the optimal adsorption capacity of 9.1 mmol/g with 5 vol%CO_(2)at 40℃.The main reason of this increased capacity could be attributed to the enhanced CO_(2)diffusion into porous adsorbent for its better dispersion in the pores of amine pillar[5]arene cavity and active site of DETA.Furthermore,the dynamic saturation adsorption capacitie of DETA-P5S were 7.11(0.37)and 6.18(0.44)mmol/g for CO_(2)/N_(2)and CO_(2)/CH_(4),respectively,both the ga mixtures showed high separation selectivity.Simultaneously,the DETA-P5S can maintain outstanding CO_(2)adsorption capacity after fifteen regeneration cycles.Consequently,the designed DETA-P5S could serve a a promising adsorbent for CO_(2)capture and storage.

Highly efficient CO_(2)capture on acid-treated sepiolite impregnated with mixed polyethyleneimine and diethanolamine

Amine-functionalized solid adsorbents exhibit broad prospects in CO_(2)capture from flue gases due to their high adsorption capacity and selectivity.However,reported adsorbents are still facing challenges,including high costs,the easy agglomeration of polyamines,and limited adsorption temperature ranges.In this study,sepiolite-based mixed amine adsorbents are prepared by synergistically impregnating acid-treated sepiolite with a mixture of polyethyleneimine(PEI)and diethanolamine(DEA).Results show that at a PEI/DEA loading ratio of 1:1 and a mixture loading of 60wt%,the CO_(2)adsorption capacity of the resulting adsorbent increases from 0.58 mmol/g for acid-treated sepiolite to 2.89 mmol/g at 60℃,and remains above 2.50 mmol/g after 10 cycles.Meanwhile,the optimized adsorbent maintains a capacity of over 2.44 mmol/g within the temperature range of 30-70↓.Additionally,the CO_(2)selectivity and maximum heat of adsorption for the optimized adsorbent are calculated to be 1184 and 60.08 kJ/mol,respectively.An improved CO_(2)adsorption capacity is obtained,an increase from 0.052 mmol/g for acid-treated sepiolite to 1.60 mmol/g.Furthermore,an in-situ diffuse reflectance infrared Fourier-transform spectroscopy(DRIFTS)analysis reveals that the introduction of DEA into PEI helps in polyamine dispersion,thereby enhancing CO_(2)adsorption capacity.The CO_(2)capture mechanism follows a zwitterionic reaction,where CO_(2)is ultimately converted into carbamate and carbamic acid.Overall,the as-prepared sepiolite-based mixed amine adsorbents,which are characterized by high CO_(2)adsorption capacity and selectivity,low cost,broad adsorption temperature range,moderate heat of adsorption,and good cycle stability,show promising potential for industrial applications.

Synthesis and modification of spherical/hollow metal-organic frameworks for efficient extraction of sulfonamides in aqueous environments

In this study,two novel spherical/hollow metal-organic frameworks were successfully synthesized,and further modified by a mild non-covalent modification strategy with dopamine and 1,4-benzenedithiol(BDT)as polymeric monomers to obtain pB DT@PDA-Ni-MOF and p BDT@PDA-Ni/Co-MOF,respectively.The results showed that the above MOFs possessed extremely fast adsorption rates and ideal adsorption capacities for sulfonamides(SAs)and the modified MOFs exhibited enhanced adsorption capacities for SAs owing to a large number of additional functional groups.Then,benefit of their regular morphology and size,a facile syringe-assisted dispersive solid phase extraction(S-DSPE)method was developed for efficient detection of SAs,which will provide a powerful tool for monitoring trace level of SAs in aqueous environment.

Heavy Metal Release from Some Industrial Wastes: Influence of Organic and Inorganic Acids, Clay Minerals, and Nanoparticles

Knowledge about heavy metal release from industrial solid wastes(ISWs) is crucial for better management of their environmental risks. This study was conducted to investigate the effect of organic and inorganic acids, clay minerals, and nanoparticles(NPs) on the release of heavy metals from sugar factory waste, ceramic factory waste, leather factory waste, and stone cutting waste. The influence of the extractants on heavy metal release from these ISWs was in the following descending order: citric acid > oxalic acid > nitric acid≥ sulfuric acid > Ca Cl2. Addition of clay minerals and NPs as adsorbents decreased heavy metal release, which was significantly lower in NP-treated wastes than in the clay mineral-treated wastes. On the other hand, the presence of organic and inorganic acids increased heavy metal adsorption by NPs and clay minerals. These results suggest that NPs can be applied successfully in waste remediation,and organic and inorganic acids play an important role in the removal of heavy metals from the studied adsorbents.

Insights into properties of activated carbons prepared from different raw precursors by pyrophosphoric acid activation

Low-cost activated carbons（ACs） were prepared from four kinds of solid wastes：petroleum coke,Enteromorpha prolifera,lignin from papermaking black liquid and hair,by pyrophosphoric acid（H_4P_2O_7） activation.Thermo-gravimetric analysis of the pyrolysis of H_4P_2O_7-precursor mixtures implied that H_4P_2O_7 had different influences on the pyrolysis behavior of the four raw materials.N_2 adsorption/desorption isotherms,scanning electron microscopy,Fourier transform infrared spectroscopy and adsorption capacities for dyes were used to characterize the prepared activated carbons.AC derived from E.prolifera exhibited the highest surface area（1094 m^2/g） and maximum monolayer adsorption capacity for malachite green（1250 mg/g）.Kinetic studies showed that the experimental data were in agreement with the pseudo-second-order model.The adsorption isotherms were well described by the Langmuir isotherm model,indicating the adsorption of dye onto the ACs proceeded by monolayers.