Sequential Production of Levulinic Acid and Porous Carbon Material from Cellulose

Abstract

A sequential production of levulinic acid (LA) and porous carbon material (CM) from cellulose was conducted by a two-step process. The cellulose was first acid hydrolyzed, and the preferred reaction conditions required a severity factor of 4.0–4.5, in which the yields of LA, formic acid, and solid residue were 38 ± 3 wt%, 17 ± 3 wt%, and 15 ± 3 wt%, respectively. The solid residue was further used for CM preparation through pyrolysis, with or without ZnCl2 activation. The ZnCl2 activation promoted the formation of CMs with improved thermal stability, high surface area (1184–2510 m2/g), and excellent phenol adsorption capacity (136–172 mg/g). The used CM can be easily regenerated by a simple methanol Soxhlet extraction process, and a comparable phenol adsorption capacity of 97 mg/g was maintained for the 5th reusing. Finally, 100 g cellulose produced 40.5 g LA, 18.9 g formic acid and 8.5 g porous CM, with a total carbon utilization ratio reaching 74.4%.

Conductive Carbon Materials from the Hydrothermal Carbonization of Vineyard Residues for the Application in Electrochemical Double-Layer Capacitors (EDLCs) and Direct Carbon Fuel Cells (DCFCs)

“…The SSAs obtained for BCs and PHCs from cellulose correspond well with literature, since similar SSAs were obtained by Kang et al [81] on pyrolyzed cellulosic hydrochar. The type IV isotherms observed for PHCs from cellulose (Figure 7B) indicate the presence of macropores.…”

Beyond Conventional Activating Methods, a Green Approach for the Synthesis of Biocarbon and Its Supercapacitor Electrode Performance

“…Moreover, sub-micropore and mesopore architectures within a porous structure provide interconnected channels throughout the fast charge/discharge route, leading to a high rate capability and enhanced charge storage capacity. Macropores also deliver ion buffering reservoirs, which shorten ion diffusion pathways into internal porosity assuring decrease in the electric resistance. − According to the International Union of Pure and Applied Chemistry, a micropore is categorized as a pore with a diameter of less than 2 nm, while a pore with size ranging between 2 and 50 mm is considered to be a mesopore, and the pore size of a macropore is larger than 50 nm …”

Challenges to Levulinic Acid and Humins Valuation in the Sugarcane Bagasse Biorefinery Concept

“…Preliminary investigations are being made and forwarded to the valuation of HUs approaching the structure and its formation mechanism [14,46]. Recently, it was demonstrated that HUs generally contained a carbon content of 60-80 wt% [55], which indicated that more than 30% of the initial carbon in cellulose was wasted as solid carbonaceous residue. As a material with high carbon content, Kang et al [55], showed that about 74.4% of the initial carbon of cellulose was transferred into value-added products, (47% carbon in LA), and also 16.1% in carbon adsorbents, especially for wastewater treatment.…”

“…Recently, it was demonstrated that HUs generally contained a carbon content of 60-80 wt% [55], which indicated that more than 30% of the initial carbon in cellulose was wasted as solid carbonaceous residue. As a material with high carbon content, Kang et al [55], showed that about 74.4% of the initial carbon of cellulose was transferred into value-added products, (47% carbon in LA), and also 16.1% in carbon adsorbents, especially for wastewater treatment. HUs represent a matrix rich in carbon and furanic structures with hydroxyl and carbonyl functional groups.…”