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

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.

An Exploratory Study of Hydrochar as a Matrix for Biotechnological Applications

“…The preparation of solid matrices was realized using a two-step procedure, with hydrothermal carbonization under standard conditions and subsequent hydrochar activation. Details of both methods are available elsewhere. , Briefly, the waste biomass/demineralized water slurry (7/1 dry weight liquid/solid) underwent hydrothermal carbonization at 200 °C for 30 min in a 250 mL autoclave reactor. The hydrochar was separated by the process water by filtration, oven-dried (105 °C, overnight), hand-milled, and sieved (ISO 3310-1 and 2 and ASTM E11, Endecott sieves).…”

“…HC-driven gas-phase adsorption studies usually make use of standard equipment . Recently, the use of laboratory-scale pressure-swing adsorption equipment introduced laboratory tests closer to the industrial situation, a strategy generally advisible for assessing the practical adsorptive potentiality of HC. Liquid-phase adsorption studies are the majority, especially in the removal of pollutants from wastewater. , More information about the interactions between HC and water-soluble proteins would be advisable. , However, the topic has potential for bulk biorefinery separation processes and innovative biocatalysis and nanoscale biomedical applications.…”

Prospects of low‐temperature solid sorbents in industrial CO₂ capture: A focus on biomass residues as precursor material

“…Otherwise, Galluci et al 309 investigated the CO 2 adsorption capacity of silver fir sawdust hydrochar produced in batches at 200°C for up to 120 min. The hydrochar was further activated by potassium hydroxide impregnation and subsequent thermal treatment (600°C, 1 h).…”

“…Otherwise, Galluci et al 309 . investigated the CO₂ adsorption capacity of silver fir sawdust hydrochar produced in batches at 200°C for up to 120 min.…”

Energy Analysis of an Integrated Plant: Fluidized Bed Steam Gasification of Hydrothermally Treated Biomass Coupled to Solid Oxide Fuel Cells

“…HTC increases the energy density of the feedstock, which is beneficial to the logistics of biomass use. Finally, in the last few years, hydrothermal conversions attracted interest for producing value-added products [22].…”