TY - JOUR
T1 - Understanding the heterogeneous catalytic mechanisms of glycerol carbonate synthesis on oil palm ash surface
T2 - A density functional theory approach
AU - Delesma, Cornelio
AU - Okoye, Patrick
AU - Castellanos-López, Moisés
AU - Longoria, Adriana
AU - Muñiz, Jesús
N1 - Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2022/1/1
Y1 - 2022/1/1
N2 - The use of glycerol as an added-value by-product from the transesterification of triglycerides to produce biodiesel has been the subject of intense research due to its versatility in a wide range of applications. In this work, a theoretical study at the density functional theory (DFT) level to categorize the most probable routes to achieve glycerol conversion was performed. Gibbs free energies were computed to assess the feasibility of the steps involved in experimental glycerol carbonate synthesis from glycerol and dimethyl carbonate. The cyclization from methyl glycerol carbonate anion to glycerol carbonate is reasonable due to the computation of the Gibbs free energy amounting to -310.0 kcal/mol, which indicates an exothermic reaction with the spontaneous rising of glycerol carbonate. The assessment of the molecular dimensions at the optimized geometry of glycerol carbonate showed a critical diameter and length of 5.25 Å and 5.90 Å, respectively; with a volume of 127.7 Å3. Charge population analysis provided insights into the electronic transfer during the reaction and the bonding mechanism resulting in the products. Additionally, the heterogeneous catalysis reaction involved in the glycerol carbonate evolution reaction and its subproducts was studied on a periodic surface model of the oil palm fuel ash catalyst in order to evaluate activation energies and the feasibility of the proposed mechanism. That is, the computations revealed an activation energy barrier of 13.4 kcal/mol (0.58 eV), which also certifies the cyclization feasibility in the formation of glycerol carbonate. The results may contribute in the insilico design of the experimental setup to improve efficiency in the process of transesterification reaction of glycerol and dimethyl carbonate to valuable glycerol carbonate.
AB - The use of glycerol as an added-value by-product from the transesterification of triglycerides to produce biodiesel has been the subject of intense research due to its versatility in a wide range of applications. In this work, a theoretical study at the density functional theory (DFT) level to categorize the most probable routes to achieve glycerol conversion was performed. Gibbs free energies were computed to assess the feasibility of the steps involved in experimental glycerol carbonate synthesis from glycerol and dimethyl carbonate. The cyclization from methyl glycerol carbonate anion to glycerol carbonate is reasonable due to the computation of the Gibbs free energy amounting to -310.0 kcal/mol, which indicates an exothermic reaction with the spontaneous rising of glycerol carbonate. The assessment of the molecular dimensions at the optimized geometry of glycerol carbonate showed a critical diameter and length of 5.25 Å and 5.90 Å, respectively; with a volume of 127.7 Å3. Charge population analysis provided insights into the electronic transfer during the reaction and the bonding mechanism resulting in the products. Additionally, the heterogeneous catalysis reaction involved in the glycerol carbonate evolution reaction and its subproducts was studied on a periodic surface model of the oil palm fuel ash catalyst in order to evaluate activation energies and the feasibility of the proposed mechanism. That is, the computations revealed an activation energy barrier of 13.4 kcal/mol (0.58 eV), which also certifies the cyclization feasibility in the formation of glycerol carbonate. The results may contribute in the insilico design of the experimental setup to improve efficiency in the process of transesterification reaction of glycerol and dimethyl carbonate to valuable glycerol carbonate.
KW - Charge transfer
KW - DFT
KW - Fuel additive
KW - Glycerol carbonate
KW - OPFA
KW - Transesterification
UR - http://www.scopus.com/inward/record.url?scp=85115780047&partnerID=8YFLogxK
U2 - 10.1016/j.fuel.2021.121874
DO - 10.1016/j.fuel.2021.121874
M3 - Artículo
AN - SCOPUS:85115780047
SN - 0016-2361
VL - 307
JO - Fuel
JF - Fuel
M1 - 121874
ER -