Catalytic hydrogenolysis of glycerol to propanediols: a review

Abstract

The catalytic hydrogenolysis of readily available glycerol to 1,2-propanediol (1,2-PD) and 1,3-propanediol (1,3-PD), which provides a new promising synthesis route to produce propanediols, has been extensively studied in the past decades. This paper summarizes the most significant reports regarding the glycerol hydrogenolysis into propanediols. Three reaction routes including the ones working towards 1,2-PD production and the recently proposed one leading to 1,3-PD production have been summarized. The catalysts used for this reaction have been classified into two categories according to the types of the metal components: the transition metal catalysts taking Cu, Ni, and Co as representative metal components and the noble metal catalysts containing Ru, Pt, Ir and Ag. Some inexpensive transition-metal catalysts exhibit high 1,2-PD selectivity and yield under mild reaction conditions, while several noble-metal catalysts are promising in synthesizing the more 2 valuable 1,3-PD. Efficient preparation methods and precise mediation techniques have been systematically developed to synthesize functionalized catalysts on the basis of the metal species in combination with acidic or basic compounds. Other technological aspects such as hydrogen sources, reaction solvents, reactor types and feeding processes were also summed in this paper. The focus of this review is on summarizing the preparation methods and the performance of various catalysts in glycerol hydrogenolysis.

Synthesis of Monoalkyl Glyceryl Ethers by Ring Opening of Glycidol with Alcohols in the Presence of Lewis Acids

“…The importance of bio‐based feedstocks in the chemical industry is continuously growing and their use is predicted to surpass that of products obtained by non‐renewable fossil sources in the near future . Indeed, the concept of biorefineries as a new sustainable scenario for the production of fuels and chemicals from biomass has gained considerable attention in recent years, in both academic and industrial environments . In particular, a sector of enormous economic relevance in this area is represented by processes that involve the conversion of glycerol, referred to as “glycerochemistry” …”

“…The present work deals with the productiono fm onoalkyl glyceryl ethers (MAGEs) through an ew reaction pathway based on the reactiono fg lycidol and alcohols catalyzed by Lewis acid-based catalysts. Glycidol is quantitatively converted with high selectivity (99 %) into MAGEs under very mild reaction conditions (80 8Ca nd 0.01 mol %c atalystl oading) in only 1husing Al(OTf) 3 or Bi(OTf) 3 as catalyst. The proposed method enhances the choice of possible green synthetic approaches for the production of value-added products such as MAGEs.…”

“…[1] Indeed, the concepto fb iorefineries as an ew sustainable scenariof or the production of fuels and chemicals from biomass has gained considerable attention in recent years, in both academic and industrial environments. [1][2][3][4] In particular, as ector of enormouse conomic relevance in this area is represented by processes that involve the conversion of glycerol, referred to as "glycerochemistry". [5][6][7][8] Glycerolh as received much attention owing to the continuous increasei nb iodiesel demand, which led the globalp roductiono fg lycerolt or each 1.5 Mt in 2015 and it is expected to rise to 2.5 Mt by 2020.…”

Catalytic Transformation of Biomass Derivatives to Value‐Added Chemicals and Fuels in Continuous Flow Microreactors

“…Novel methods have gained interests recently to obtain more pure forms of lignin that are easier to process. [95,96] It can also react with CO (by carbonylation) or CO 2 (by carboxylation) to glycerol carbonate (a solvent and monomer for polyesters, polycarbonates, etc. [84][85][86][87][88] Top value-added chemicals derived from (pyrolytic) lignin are mainly aromatic components (e. g., BTX), [89] phenol and a variety of lignin monomer molecules (e. g., propylphenol, eugenol, syringol, aryl ethers or alkylated methyl aryl ethers).…”

Effect of Ru Precursors and Reduction Conditions on Catalyst Performance in Glycerol Hydrogenolysis

“…Catalytic hydrogenolysis of glycerol has been extensively studied which has been also summarized and discussed in several recent reviews . In general, catalytic activity and product selectivity were found to be sensitive to the type of active (hydrogenation) metal and acid and/or base co‐catalyst .…”