Research progress of catalysts and reaction mechanism in glycerol condensation to acetone glycidol

With the booming of biodiesel industry, it is urgent to high-valued to recycle glycerol as the main by-product. The condensation of glycerol (GLY) with acetone to produce acetone glycidol (2, 2-dimethyl-1, 3-dioxolane-4-methanol, Solketal) is promising direction for GLY utilization, because Solketal can function as fuel additive to modify the fuel viscosity and low-temperature performance of oil significantly, and reduce the emission of carbon monoxide, small solid particles and other environmentally unfriendly substances further. However, the reaction needs to be accelerated by the catalyst with acid nature, thus the design and modification over the structure and acid properties of catalysts are dominating the process of glycerol ketonization reaction. So, this paper systematically reviews the progress of homogeneous and heterogeneous acid catalysts, and the reaction mechanism in recent years. It is classified based on the structural properties, advantages and characteristics of different catalysts, and influences of their structural properties on catalytic activity. Finally, some future directions for this research field are pointed out.