Biomass Valorization to Produce Porous Carbons: Applications in CO2 Capture and Biogas Upgrading to Biomethane—A Mini-Review

Maria Bernardo,Isabel Fonseca,Isabel A A C Esteves,Nuno Lapa

doi:10.3389/fenrg.2021.625188

Maria Bernardo, Isabel Fonseca + Show 2 more

Open Access

https://doi.org/10.3389/fenrg.2021.625188

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Abstract

Porous carbon materials, derived from biomass wastes and/or as by-products, are considered versatile, economical and environmentally sustainable. Recently, their high adsorption capacity has led to an increased interest in several environmental applications related to separation/purification both in liquid- and gas-phases. Specifically, their use in carbon dioxide (CO2) capture/sequestration has been a hot topic in the framework of gas adsorption applications. Cost effective biomass porous carbons with enhanced textural properties and high CO2 uptakes present themselves as attractive alternative adsorbents with potential to be used in CO2 capture/separation, apart from zeolites, commercial activated carbons and metal-organic frameworks (MOFs). The renewable and sustainable character of the precursor of these bioadsorbents must be highlighted in the context of a circular-economy and emergent renewable energy market to reach the EU climate and energy goals. This mini-review summarizes the current understandings and discussions about the development of porous carbons derived from bio-wastes, focusing their application to capture CO2 and upgrade biogas to biomethane by adsorption-based processes. Biogas is composed by 55–65 v/v% of methane (CH4) mainly in 35–45 v/v% of CO2. The biogas upgraded to bio-CH4 (97%v/v) through an adsorption process yields after proper conditioning to high quality biomethane and replaces natural gas of fossil source. The circular-economy impact of bio-CH4 production is further enhanced by the use of biomass-derived porous carbons employed in the production process.

Highlights

Biogas produced from several biomasses is a renewable fuel source of methane that after proper conditioning can be injected into the gas pipeline networks or used as energy for transport (Scarlat et al, 2018; Ferella et al, 2019)
Fresh overviews devoted to the state of the art of adsorbents for CO2 removal have been focused on biomass derived porous carbons (Singh et al, 2019; Xu and Strømme, 2019; Sher et al, 2020)
Much of the research lacks the use of biomass-derived adsorbents employed themselves as keymaterials to capture CO2 and upgrade biogas to bio-CH4 by adsorption-based processes (PSA), in a concept of a circulareconomy (Cheng et al, 2020; Sherwood, 2020; D’Adamo et al, 2021; Kumar and Verma, 2021)

Summary

Introduction

Biogas produced from several biomasses is a renewable fuel source of methane that after proper conditioning can be injected into the gas pipeline networks or used as energy for transport (Scarlat et al, 2018; Ferella et al, 2019). The key element in Biomass-Derived Porous Carbons for Biogas Upgrading adsorption-based processes is the need for an effective adsorbent with high adsorption capacities for the species to capture, low productions cost and low environmental impacts. Much of the research lacks the use of biomass-derived adsorbents employed themselves as keymaterials to capture CO2 and upgrade biogas to bio-CH4 by adsorption-based processes (PSA), in a concept of a circulareconomy (Cheng et al, 2020; Sherwood, 2020; D’Adamo et al, 2021; Kumar and Verma, 2021).

Results

Conclusion