Non-Energy Valorization of Residual Biomasses via HTC: CO2 Capture onto Activated Hydrochars

Katia Gallucci,Francesco Di Lauro,Luca Taglieri,Zaheer Ahmad,Alessandro Antonio Papa,Alberto Gallifuoco

doi:10.3390/app10051879

Abstract

This study aims to investigate the CO2 sorption capacity of hydrochar, obtained via hydrothermal carbonization (HTC). Silver fir sawdust was used as a model material. The batch runs went at 200 °C and up to 120 min. The hydrochar was activated with potassium hydroxide impregnation and subsequent thermal treatment (600 °C, 1 h). CO2 capture was assayed using a pressure swing adsorption (PSA) process. The morphology and porosity of hydrochar, characterized through Brunauer-Emmett-Teller, Barrett-Joyner-Halenda (BET-BJH) and scanning electron microscopy (SEM) analyses, were reported and the sorbent capacity was compared with traditional sorbents. The hydrochar recovered immediately after the warm-up of the HTC reactor had better performances. The Langmuir equilibrium isotherm fits the experimental data satisfactorily. Selectivity tests performed with a model biogas mixture indicated a possible use of hydrochar for sustainable upgrading of biogas to bio-methane. It is conceivably a new, feasible, and promising option for CO2 capture with low cost, environmentally friendly materials.

Highlights

Growing population and economy race are the two main concerns regarding the increase in emissions of greenhouse gases (GHG) and, subsequently, the accelerating climate change and global warming
Worldwide researchers recognize the need for a sustainable development and more equity, including poverty eradication, and provide an ethical foundation for limiting the effects of climate changes
Many of the countries most vulnerable to climate change contribute little to GHG emissions

Summary

Introduction

Growing population and economy race are the two main concerns regarding the increase in emissions of greenhouse gases (GHG) and, subsequently, the accelerating climate change and global warming. Carbon dioxide is the first responsible for these unwanted effects [1]. CO2 emissions is one of the most challenging issues facing humanity [2]. Global climate reports show that the average world temperature is steadily increasing with respect to 20th century data [3]. Worldwide researchers recognize the need for a sustainable development and more equity, including poverty eradication, and provide an ethical foundation for limiting the effects of climate changes. The rate of atmospheric accumulation of GHGs and the capacity to address its mitigation and adaptation differ for each nation. Many of the countries most vulnerable to climate change contribute little to GHG emissions

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