Increasing demand for biodiesel production would lead to tremendous supply of glycerol as a coproduct, which is almost 10% by weight. Therefore, utilization of bioglycerol into valuable chemicals is timely to reduce the cost of biodiesel. Both 1,2and 1,3-propanediols are very useful chemicals which can be produced from glycerol. This paper describes a novel process for selective hydrogenolysis of glycerol to 1,2-propanediol over silver incorporated octahedral molecular sieve (OMS-2) catalyst. Also, the current work describes the use of silver as the catalyst for the first time for hydrogenolysis of glycerol. Both batch and continuous mode of operations have been studied to determine the stability of the catalyst. Different loadings (10À30% w/w) of Ag were incorporated in OMS-2 by the precipitation method and used in the reaction. Thirty % w/w Ag-OMS-2 was the best catalyst. It was characterized by various techniques such as SEM, TGA, XRD, N 2 adsorptionÀdesorption, EDAX, TPD-TPR, and FTIR. It is a nano fibrous crystalline material. This Article reports a comprehensive account of this catalytic process.The initial studies were carried out in a batch reactor to optimize the reaction parameters. High conversion of glycerol (about 65À70%) with about 90% selectivity toward 1,2-propanediol was obtained within 8 h under hydrogen pressure. The time-on-stream (TOS) analysis studies were conducted in a fixed bed reactor up to 150 h, which demonstrated that the catalyst was stable and the process has a potential for commercial exploitation. methane sulfonic acid in a water-sulfolane mixture resulted in to 1-propanol, 1,2-PDO, and 1,3-PDO in a 47:22:31 ratio. 12 Dehydroxylation of glycerol in sulfolane catalyzed by a homogeneous complex of ruthenium as catalyst at 52 atm and 110 °C resulting in to very low yields 1,2-/1,3-PDO is reported. 13 The hydrogenolysis of glycerol with copperÀchromiumbased catalysts yielded only 1,2-PDO. 14 Hydrogenolysis of glycerol under 30 MPa H 2 at 260 °C over Raney Ni, Ru, Rh, and Ir catalysts yielded mainly methane, but in the presence of Raney Cu, 1,2-PDO was the main product. 15 Furthermore, other catalysts such as Cu/C, 16 CuÀPt, and CuÀRu bimetallic catalysts 17 have been reported at 1.0À4.0 MPa and 493À513 K. Hydrogenolysis of glycerol and other polyols over Ni/Re catalyst under 8.2 MPa H 2 and 230 °C in 4 h led to 44% 1,2-PDO, 5% 1,3-PDO and 13% ethylene glycol. 18 Glycerol hydrogenolysis on several heterogeneous catalysts under 8 MPa H 2 pressure at 180 °C was investigated over various metals (Cu, Pd, Ni and Rh), supports (ZnO, C and Al 2 O 3 ), solvents (H 2 O, sulfolane and dioxane), and additives (H 2 WO 4 ) were tested to improve the reaction rate and selectivity. 19 Glycerol hydrogenolysis to ethylene glycol and 1,2-PDO was reported with Rh/SiO 2 catalysts including the effect of sulfur and temperature. 20À22 Hydrogenolysis of glycerol over carbon-supported Ru, Pt, and bimetallic PtÀRu and AuÀRu catalysts is also reported. 23,24 The effects of NaOH and CaO addition on the reaction...

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Aromatic as well as aliphatic esters comprise important class of chemicals having variety of applications. Valuable chemicals can be produced from 1,2-propanediol (1,2-PDO) by etherification, esterification and cyclization through acetalization....

Value addition to glycerol, the sole co-product in biodiesel production, will lead to reform of the overall biodiesel economy. Different valuable chemicals can be produced from glycerol using heterogeneous catalysis and these valuable chemicals are useful in industries such as cosmetics, pharmaceuticals, fuels, soap, paints, and fine chemicals. Therefore, the conversion of glycerol to valuable chemicals using heterogeneous catalysis is a noteworthy area of research. Etherification of glycerol with alkenes or alcohols is an important reaction in converting glycerol to various value-added chemicals. This article describes reaction of glycerol with benzyl alcohol in solvent-free medium by using a clay supported modified heteropolyacid (HPA), Cs2.5H0.5PW12O40/K-10 (Cs-DTP/K-10) as solid catalyst and its comparison with other catalysts in a batch reactor. Mono-Benzyl glycerol ether (MBGE) was the major product formed in the reaction along with formation of di-benzyl glycerol ether (DBGE). The effects of different parameters were studied to optimize the reaction parameters. This work provides an insight into characterization of Cs2.5H0.5PW12O40/K-10 catalyst by advanced techniques such as surface area measurement, X-ray analysis, ICP-MS, FT-IR, and SEM. Reaction products were characterized and confirmed by using the GCMS method. The kinetic model was developed from an insight into the reaction mechanism. The apparent energy of activation was found to be 18.84 kcal/mol.

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