Synthesis of oxygenated additive fuels from bio-renewable glycerol using sulfated Zr-Al based heterogeneous acid catalyst

High value-added fuel additive production from waste bio-glycerol over a versatile nanohybrid catalyst

“…Initially, acetone and glycerol molecules are activated by the acido-basic sites present in the MAZ catalyst, leading to the formation of polarized acetone and glyceroxide species. 10,55 Subsequently, these glyceroxide and polarized acetone species interact with acetone and glycerol molecules, resulting in the formation of solketal through dehydration followed by a cyclization step. Solketal is thermodynamically less stable but kinetically more favorable, making it the major product in the glycerol acetalization reaction.…”

“…These results suggest that the observed increase in glycerol conversion is likely due to improved glycerol accessibility in acetone, thereby shifting the equilibrium towards the product side and enhancing solketal formation. 10 3.2.3 Effect of reaction time. To examine the variation in glycerol conversion and product selectivity at different time intervals ranging from 1 to 3 hours, the acetalization of glycerol with acetone over the MAZ nanohybrid catalyst at 60 1C and ambient pressure was analyzed to determine the optimum solketal yield.…”

“…Among these, the acetalization reaction of glycerol to produce solketal is of great interest due to its wide range of applications, i.e., it can be used as a fuel additive in gasoline/diesel, as a food additive, and in cosmetic production, and can be used for reducing gum formation in gasoline and reducing the viscosity of biodiesel. 10,11 Traditionally, solketal is produced over a homogeneous catalyst by an acetalization reaction of glycerol and acetone molecules. 12 However poor recyclability, use of hazardous solvents, reactor corrosion, difficulty in catalyst separation, and lower conversion are the main drawbacks of homogeneous catalysts.…”

“…, it can be used as a fuel additive in gasoline/diesel, as a food additive, and in cosmetic production, and can be used for reducing gum formation in gasoline and reducing the viscosity of biodiesel. 10,11…”

“…12 However poor recyclability, use of hazardous solvents, reactor corrosion, difficulty in catalyst separation, and lower conversion are the main drawbacks of homogeneous catalysts. Therefore, heterogeneous catalysts, such as WO 3 /Nb 2 O 5 , 13 MoO 3 -ZrO 2 , 14 SO 4 −2 /ZrO 2 -Al 2 O 3 , 15 sulphated Al-MCM-41, 16 FeCl 3 /γ-Al 2 O 3 , 17 Si induced heteropoly acid, 18 (C 3 H 7 ) 4 N + /PWA, 19 sulfonated mesoporous polymers, 20 acid-functionalized carbons, 21 H-beta zeolite, 22,23 molybdenum and tungsten-promoted SnO 2 , 24 mesostructured silica, 25 zirconia, 26 and mixed metal oxides, 27 are explored for solketal formation, but low glycerol conversion, high cost of catalysts, use of solvents in the reaction medium, and poor recyclability are the drawbacks of these catalyst systems. In addition, metal-functionalized zeolites such as Cu-mordenite, 28 Nb-Y zeolite, 29 etc.…”