Activity of a Sulfonated Carbon-Based Catalyst Derived from Organosolv Lignin toward Esterification of Stearic Acid under Near-Critical Alcohol Conditions

Abstract

In this study, an environmentally benign carbon-based catalyst derived from extracted bagasse lignin (EL) was successfully synthesized by solvothermal carbonization and sulfonation with methane sulfonic acid (MSA). Interestingly, the results indicated that the use of MSA as a sulfonation agent made a catalyst with higher thermal stability than conventional sulfuric acid. Thus, in comparison to the catalyst prepared by using sulfuric acid, the catalyst prepared by using MSA (EL–MSA) exhibited higher catalytic activity in the esterification of stearic acid under near-critical methanol conditions. Under optimum conditions (260 °C for 5 min, a 9:1 methanol-to-stearic-acid molar ratio, 5 wt % catalyst loading, and 10% v/v toluene), the esterification over the EL–MSA catalyst promoted a 91.1% methyl stearate yield. Moreover, the results also revealed that the high thermal stability of the EL–MSA catalyst not only affects its great catalytic activity, but it also prevents damage to the porous structure and decomposition of acidic surface oxygen-containing functional groups. It contributes to the excellent reusability of the catalyst. After the fifth run, a high yield of 82.8% was obtained. The effect of alcohol type on the catalyst performance was also studied. It was found that the EL–MSA catalyst also presented good performance toward esterification with ethanol and propanol, from which ethyl stearate and propyl stearate with a more than 80% ester yield can be achieved.

Thermocatalytic Decomposition of Methane: A Review on Carbon-Based Catalysts

“…The presence of oxygenated surface groups, such as carboxylic, phenolic, lactonic, and carbonylic groups, is known to significantly affect the chemical and catalytic activities of carbon catalysts. , Surface functional groups on ACs are located at the edges represented by the noncarbon heteroatoms such as nitrogen, phosphorus, hydrogen, and oxygen (Figure ). The acidic nature of ACs is formed through bonding with these heteroatoms, which come from oxygen functional groups and can enhance the catalytic performance of carbon in the initial stage by either directly reacting with methane or by generating new reacting sites by releasing CO x .…”

Optimization of the catalytic production of methyl stearate by applying response surface Box–Behnken design: an intensified green option for high-cetane biofuel manufacture

“…Concerning MST production, it is well known that this alkyl ester can be synthesized via the esterication of stearic acid (SA) with methanol following homogeneous, heterogeneous, or enzymatic routes; however, the number of reports dealing with the synthesis of MST is scarce contrasting to what is found for other alkyl esters. Regarding the heterogeneous route for MST production, some catalysts including montmorillonite-based clays, [8][9][10][11] Amberlyst-15, 12 Nb 2 O 5 , 13 tin zirconium oxide, 14 amidoximated polyacrylonitrile ion exchange bres, 15 carbon-based catalyst 16 and sulfated ZrO 2 -SiO 2 (ref. 17) have been tested.…”

Encapsulation of AgNPs in a Lignin Isocyanate Film: Characterization and Antimicrobial Properties

“…On the other hand, the organosolv process allows the delignification of lignocellulosic biomass in an environmentally benign manner with little alterations to lignins structure [ 13 , 14 , 15 , 16 ]. Because of its renewability, abundance, low cost, and presence of a plethora of functional groups, it is considered to be a promising biobased polyol substitute for polyurethane (PU) production [ 17 ].…”

“…Lignin is isolated from different plant samples which contain complex polymers that need harsh or mild solvents for depolymerization such acid hydrolysis, alkaline hydrolysis, enzyme, reductive or oxidative fractionation, and combined pretreatment methods (Figure 2) [11,12]. On the other hand, the organosolv process allows the delignification of lignocellulosic biomass in an environmentally benign manner with little alterations to lignins structure [13][14][15][16]. Because of its renewability, abundance, low cost, and presence of a plethora of functional groups, it is considered to be a promising biobased polyol substitute for polyurethane (PU) production [17].…”

“…By incorporating lignin into the PUF, the glass transition temperature, the crosslinking density, and the mechanical stress of the PUF were ultimately improved [18,20,21]. Polyurethane films prepared using lignin have also been shown to have a high UV absorbance, good mechanical properties, and high thermal On the other hand, the organosolv process allows the delignification of lignocellulosic biomass in an environmentally benign manner with little alterations to lignins structure [13][14][15][16]. Because of its renewability, abundance, low cost, and presence of a plethora of functional groups, it is considered to be a promising biobased polyol substitute for polyurethane (PU) production [17].…”