Efficacies of Carbon-Based Adsorbents for Carbon Dioxide Capture

Tasmina Khandaker,Muhammad Hossain,Palash Dhar,Mohammad Ahmed,Md Hossain,Md Rahman

doi:10.3390/pr8060654

Abstract

Carbon dioxide (CO2), a major greenhouse gas, capture has recently become a crucial technological solution to reduce atmospheric emissions from fossil fuel burning. Thereafter, many efforts have been put forwarded to reduce the burden on climate change by capturing and separating CO2, especially from larger power plants and from the air through the utilization of different technologies (e.g., membrane, absorption, microbial, cryogenic, chemical looping, and so on). Those technologies have often suffered from high operating costs and huge energy consumption. On the right side, physical process, such as adsorption, is a cost-effective process, which has been widely used to adsorb different contaminants, including CO2. Henceforth, this review covered the overall efficacies of CO2 adsorption from air at 196 K to 343 K and different pressures by the carbon-based materials (CBMs). Subsequently, we also addressed the associated challenges and future opportunities for CBMs. According to this review, the efficacies of various CBMs for CO2 adsorption have followed the order of carbon nanomaterials (i.e., graphene, graphene oxides, carbon nanotubes, and their composites) < mesoporous -microporous or hierarchical porous carbons < biochar and activated biochar < activated carbons.

Highlights

Fossil fuels supply more than 98% of the world’s energy demands [1]
The further modification of those materials can significantly increase the cost, such as composite materials preparation and fabrication for the end-use. Their average CO2 adsorption capacity values were 5.13 ± 1.62 and 3.23 ± 1.13 mmol/g, respectively, at 273 and 298 K, which was even lower than that of cheap materials, such as biochar at both temperatures (Figure 4). These results indicate that graphene, graphene oxide, and carbon nanotubes (CNTs) have lower CO2 adsorption capacity compared to biochar and activated biochar and even compared with other types of carbon-based materials (CBMs)
CBMs are very efficient in the capture of CO2 from the air at different temperatures and pressures due to their specific properties, including high surface area, mesoporosity, microporosity, micropore volume, well-defined pore size distributions, and high stability, at different environmental conditions

Summary

Introduction

Fossil fuels supply more than 98% of the world’s energy demands [1]. Due to the burning of fossil fuels in industrial activities, the concentration of CO2 has been increasing in the atmosphere significantly [2]. Membrane separation techniques have been utilized for the capture of CO2 at low pressure These kind of technologies often suffers from high operating costs, and they are non-energy efficient to compress the Processes 2020, 8, 654; doi:10.3390/pr8060654 www.mdpi.com/journal/processes. CO2 capture via solid-state materials (e.g., adsorption technology) is very cost-effective, easy to (such as amine-based adsorption technology),. (e.g., adsorption design, has a functional surface, hydrophobicity, need low energy consumption, simple operation, technology) is very cost-effective, easy to design, has a functional surface, hydrophobicity, need low and easy regeneration of adsorbents [11,12,13,14,15]. The subsequent objective of this review was to provide from the air at different temperatures and pressures. CBMs (carbon-based materials) for CO2 capture through adsorption technology

Efficacy of CBMs for CO2 Capture

Biochar for among

Comparative Analysis of CBMs Performances

Future Challenges and Opportunities

Findings

Conclusions