Biobased catalyst in biorefinery processes: sulphonated hydrothermal carbon for glycerol esterification

Abstract

Sulphonated hydrothermal carbon (SHTC), obtained from D-glucose by mild hydrothermal carbonisation and subsequent sulphonation with sulphuric acid, is able to catalyse the esterification of glycerol with different carboxylic acids, namely, acetic, butyric and caprylic acids. Product selectivity can be tuned by simply controlling the reaction conditions. On the one hand, SHTC provides one of the best selectivity towards monoacetins described up to now without the need for an excess of glycerol. On the other hand, excellent selectivity towards triacylglycerides (TAG) can be obtained, beyond those described with other solid catalysts, including well-known sulphonic resins. Recovery of the catalyst showed partial deactivation of the solid. The formation of sulphonate esters on the surface, confirmed by solid state NMR, was the cause of this behaviour. Acid treatment of the used catalyst, with subsequent hydrolysis of the surface sulphonate esters, allows SHTC to recover its activity. The higher selectivity towards mono-and triesters and its renewable origin makes SHTC an attractive catalyst in biorefinery processes.

Selective esterification of fatty acids with glycerol to monoglycerides over –SO3H functionalized carbon catalysts

“…The XRD patterns of the carbon catalysts (not shown here) resembled those of the sulfonated carbons reported in our previous works and consistent with an amorphous carbon structure giving rise to broad, weak C(002) and C(101) diffraction peaks near 2h = 15°-30°and 40°-50°(absent in the case of HTCSO3H), respectively [18][19][20][21][22][23].…”

“…These materials have gained considerable attention as novel, recyclable substitutes to mineral acid catalysts subsequently independently applied by different authors in various liquid phase reactions such as esterification, hydrolysis, transesterification, acetylation etc. [17][18][19][20][21][22][23]. However, till date, no reports could be found in open literature depicting the catalytic application of such -SO 3 H containing carbon materials (sulfonated carbons) for the esterification of glycerol with long chain fatty acids (lauric, oleic etc.).…”

Levulinic Acid Biorefineries: New Challenges for Efficient Utilization of Biomass

“…Roldan et al [98] have optimized esterification catalysts obtained by hydrothermalc arbonization of glucose for the production of glycerole sters. The highest selectivity of the sulfonated catalysts is obtained at mid-reaction temperatures of 90-110 8Cand is 57 %f or triacylglycerides, whereas the selectivity of diacylglycerides is approximately 38 %.…”

Application of Heterogeneous Catalysts in the First Steps of the Oseltamivir Synthesis

“… SAC-13 [26]: nafion-silica composite, with perfluoroalkyl sulfonic groups.  sulfonated hydrothermal carbon (SHTC): prepared from glucose under mild conditions and sulfonated with sulfuric acid [27] that contains arylsulfonic groups and has shown improved activity in different esterification reactions [28,29]. The results obtained with all the sulfonic catalysts are collected in Table 1.…”

“…• sulfonated hydrothermal carbon (SHTC): prepared from glucose under mild conditions and sulfonated with sulfuric acid [27] that contains arylsulfonic groups and has shown improved activity in different esterification reactions [28,29].…”