Large-scale Preparation Of Shaped Porous Carbon Materials For CO₂ Adsorption

Nowadays,energy conservation and environmental protection along with economic globalization are becoming more and more important,carbon dioxide?CO₂?plays the dual role of the main cause of the greenhouse effect and chemical production of important raw materials.Whether in academic research or engineering applications,CO₂ capture and separation technology has received extensive attention.Currently,there are four major CO₂ capture and separation technologies,chemical absorption,membrane separation,cryogenic distillation,and physical adsorption.Among them,the main advantages of the physisorption method are the simple equipment and process,low energy consumption,no corrosion to the equipment and large depth of removal.The key to physisorption is the design and large-scale preparation of cheap adsorbent materials which is efficient and environmental friendly,and also be stable in chemical and physical properties.Under the above research background,this article conducted the experiment and then the performance evaluation mainly focus on the physical adsorption method.Using the principle of organic-inorganic hybridization,a high mechanical strength monolithic porous carbon adsorbent was prepared by a sol-gel method.On this basis,a large-scale amplification was performed and the material was applied to the simulation of CO₂ capture in flue gas.Set separation.details as follows:?1?For commercial activated carbon commonly used as industrial absorbents,the mechanical strength of commercial activated carbon is not high and the carbon powder is easily pulverized under the impact of gas stream.In this chapter,resorcinol,formaldehyde and melamine are used as functional organic carbon sources,and Laponite is used in this chapter.As an inorganic dopant,a series of high mechanical strength monolithic porous carbonaceous adsorbents was prepared by varying the amount of Laponite.The reason for the stable mechanical properties of this composite material is explained from a microscopic point of view.In addition,the pore structure analysis showed that the prepared organic-inorganic hybrid materials produced a hierarchical structure after carbonization,which explained the reasons for the formation of hierarchical structure from the perspective of material synthesis.Compared with industrial carbon adsorbents,this type of adsorbent has the advantages of mild preparation conditions,controllable morphology and structure,and resistance to airflow shocks that are not easily pulverized.CO₂ performance evaluation showed that CO₂ adsorption was 2 mmol g^-1 at25°C under atmospheric pressure,and the cycle regeneration performance was excellent.?2?In view of the complex preparation process of industrial adsorbents and the problem of poor adsorption capacity and selectivity,this chapter builds on the previous chapter to further develop high porosity carbon adsorbents and achieve carbon adsorption under laboratory conditions.The agent is prepared on a large scale.The precursor composites were prepared in one step by sol-gel method.The precursors were sprayed with K₂CO₃ solution and then extruded into a cylindrical composite.The carbon composites were activated by carbonization to prepare high-porosity cylindrical carbon material.The specific samples of the series are all above 1300 m² g^-1,possessing a hierarchical structure,and the compressive strength of the sample can higher than 120 N/cm.CO₂ performance evaluation showed that the adsorption capacity of CO₂ was 5 mmol g^-1 at 25°C,and CO₂ adsorption was still 2.5 mmol g^-1 at 75°C.The equivalent heat of adsorption of the series of samples calculated by the Clausius-Clapeyron equation is less than 30 kJ mol^-1,indicating that the interaction between the sample and CO₂ is physical adsorption,which is conducive to gas separation.