Preparation of Microporous Carbon from Sargassum horneri by Hydrothermal Carbonization and KOH Activation for CO2 Capture

Ganning Zeng,Huijuan Ying,Xi Wu,Jiawei Wang,Xin Dou,Sa Lou,Ning Ai

doi:10.1155/2018/4319149

Ganning Zeng, Huijuan Ying + Show 5 more

Open Access

https://doi.org/10.1155/2018/4319149

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Abstract

High-performance microporous activated carbon (AHC) for CO2 capture was prepared from an emerging marine pollutant, Sargassum horneri, via hydrothermal carbonization (HTC) and KOH activation. The as-synthesized carbon material was characterized by N2 sorption-desorption measurement, TGA, SEM, XRD, FTIR, and elemental analysis. Impressively, the activated carbon exhibited high specific surface area (1221 m2/g), narrow distributed micropores (∼0.50 nm), and a relatively high nitrogen content (3.56 wt.%), which endowed this carbon material high CO2 uptake of 101.7 mg/g at 30°C and 1 bar. Moreover, the carbon material showed highly stable CO2 adsorption capacity and easy regeneration over four adsorption-desorption cycles. Two kinetic models were employed in this work and found that the pseudo-first-order kinetic model (R2 = 0.99) provided the best description. In addition, the high CO2 uptake is mainly attributed to the presence of abundant narrow microporous. The macroporous structure of hydrochar (HC) played an important role in the production of microporous carbon with high adsorption properties. This work provides an efficient strategy for preparing microporous activated carbon from Sargassum horneri, and AHC is a promising candidate acting as an efficient CO2 adsorbent for further industrial application.

Highlights

Diverse groups of organisms are found living in the ocean, of which, macroalgae is at least 10,000 different species described to date
We reported a facile method to synthesis microporous activated carbon with large quantities of narrow micropores (∼0.50 nm). e synthesis was performed under mild hydrothermal conditions and subsequent KOH activation, and the product was applied for carbon capture and storage (CCS). e CO2 capture capacity, kinetics, and regeneration of microporous carbon were investigated
In the derivative thermogravimetry (DTG) curve, two extensive peaks were detected between 200 and 350°C. e first peak and the second peak below 350°C might be associated with the decomposition of carbohydrates and proteins, respectively. e thermal degradation patterns were similar to that of macroalgae reported by Li et al [42]. e weight loss of the final stage at a temperature range of 400–800°C might be attributed to the degradation of lignin and remaining proteins [43]

Summary

Introduction

Diverse groups of organisms are found living in the ocean, of which, macroalgae is at least 10,000 different species described to date. Hydrothermal carbonization (HTC) is a thermochemical conversion process where an organic substrate is converted into a solid product enriched in carbon content in the presence of water [16]. It was first described in 1913 by Bergius and was reintroduced to the public in the 21st century by Titirici and Antonietti in Germany [17]. In terms of the CO2 capture by activated carbons, it has been reported that the narrow micropores play a decisive role in CO2 adsorption capacity [20,21,22,23]. We reported a facile method to synthesis microporous activated carbon with large quantities of narrow micropores (∼0.50 nm). e synthesis was performed under mild hydrothermal conditions and subsequent KOH activation, and the product was applied for carbon capture and storage (CCS). e CO2 capture capacity, kinetics, and regeneration of microporous carbon were investigated

Materials and Methods

Results and Discussion

Decarboxylation

Conclusion